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Duarte ME, Parnsen W, Zhang S, Abreu MLT, Kim SW. Low crude protein formulation with supplemental amino acids for its impacts on intestinal health and growth performance of growing-finishing pigs. J Anim Sci Biotechnol 2024; 15:55. [PMID: 38528636 PMCID: PMC10962153 DOI: 10.1186/s40104-024-01015-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 02/14/2024] [Indexed: 03/27/2024] Open
Abstract
BACKGROUND Low crude protein (CP) formulations with supplemental amino acids (AA) are used to enhance intestinal health, reduce costs, minimize environmental impact, and maintain growth performance of pigs. However, extensive reduction of dietary CP can compromise growth performance due to limited synthesis of non-essential AA and limited availability of bioactive compounds from protein supplements even when AA requirements are met. Moreover, implementing a low CP formulation can increase the net energy (NE) content in feeds causing excessive fat deposition. Additional supplementation of functional AA, coupled with low CP formulation could further enhance intestinal health and glucose metabolism, improving nitrogen utilization, and growth performance. Three experiments were conducted to evaluate the effects of low CP formulations with supplemental AA on the intestinal health and growth performance of growing-finishing pigs. METHODS In Exp. 1, 90 pigs (19.7 ± 1.1 kg, 45 barrows and 45 gilts) were assigned to 3 treatments: CON (18.0% CP, supplementing Lys, Met, and Thr), LCP (16.0% CP, supplementing Lys, Met, Thr, Trp, and Val), and LCPT (16.1% CP, LCP + 0.05% SID Trp). In Exp. 2, 72 pigs (34.2 ± 4.2 kg BW) were assigned to 3 treatments: CON (17.7% CP, meeting the requirements of Lys, Met, Thr, and Trp); LCP (15.0% CP, meeting Lys, Thr, Trp, Met, Val, Ile, and Phe); and VLCP (12.8% CP, meeting Lys, Thr, Trp, Met, Val, Ile, Phe, His, and Leu). In Exp. 3, 72 pigs (54.1 ± 5.9 kg BW) were assigned to 3 treatments and fed experimental diets for 3 phases (grower 2, finishing 1, and finishing 2). Treatments were CON (18.0%, 13.8%, 12.7% CP for 3 phases; meeting Lys, Met, Thr, and Trp); LCP (13.5%, 11.4%, 10.4% CP for 3 phases; meeting Lys, Thr, Trp, Met, Val, Ile, and Phe); and LCPG (14.1%, 12.8%, 11.1% CP for 3 phases; LCP + Glu to match SID Glu with CON). All diets had 2.6 Mcal/kg NE. RESULTS In Exp. 1, overall, the growth performance did not differ among treatments. The LCPT increased (P < 0.05) Claudin-1 expression in the duodenum and jejunum. The LCP and LCPT increased (P < 0.05) CAT-1, 4F2hc, and B0AT expressions in the jejunum. In Exp. 2, overall, the VLCP reduced (P < 0.05) G:F and BUN. The LCP and VLCP increased (P < 0.05) the backfat thickness (BFT). In Exp. 3, overall, growth performance and BFT did not differ among treatments. The LCPG reduced (P < 0.05) BUN, whereas increased the insulin in plasma. The LCP and LCPG reduced (P < 0.05) the abundance of Streptococcaceae, whereas the LCP reduced (P < 0.05) Erysipelotrichaceae, and the alpha diversity. CONCLUSIONS When implementing low CP formulation, CP can be reduced by supplementation of Lys, Thr, Met, Trp, Val, and Ile without affecting the growth performance of growing-finishing pigs when NE is adjusted to avoid increased fat deposition. Supplementation of Trp above the requirement or supplementation of Glu in low CP formulation seems to benefit intestinal health as well as improved nitrogen utilization and glucose metabolism.
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Affiliation(s)
- Marcos Elias Duarte
- Department of Animal Science, North Carolina State University, Raleigh, NC, 27695, USA
| | - Wanpuech Parnsen
- Department of Animal Science, North Carolina State University, Raleigh, NC, 27695, USA
| | - Shihai Zhang
- Department of Animal Science, North Carolina State University, Raleigh, NC, 27695, USA
| | - Márvio L T Abreu
- Department of Animal Science, North Carolina State University, Raleigh, NC, 27695, USA
| | - Sung Woo Kim
- Department of Animal Science, North Carolina State University, Raleigh, NC, 27695, USA.
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Kirupananthan D, Bertolo RF, Brunton JA. Lysine Dipeptide Enhances Gut Structure and Whole-Body Protein Synthesis in Neonatal Piglets with Intestinal Atrophy. J Nutr 2022; 152:1843-1850. [PMID: 35481706 DOI: 10.1093/jn/nxac095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/28/2022] [Accepted: 04/21/2022] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Parenteral nutrition (PN) is often a necessity for preterm infants; however, prolonged PN leads to gut atrophy, weakened gut barrier function, and a higher risk of intestinal infections. Peptide transporter-1 (PepT1) is a di- or tripeptide transporter in the gut and, unlike other nutrient transporters, its activity is preserved with the onset of intestinal atrophy from PN. As such, enteral amino acids in the form of dipeptides may be more bioavailable than free amino acids when atrophy is present. OBJECTIVES In Yucatan miniature piglets with PN-induced intestinal atrophy, we sought to determine the structural and functional effects of enteral refeeding with lysine as a dipeptide, compared to free L-lysine. METHODS Piglets aged 7-8 days were PN-fed for 4 days to induce intestinal atrophy, then were refed with enteral diets with equimolar lysine supplied as lysyl-lysine (Lys-Lys; n = 7), free lysine (n = 7), or Lys-Lys with glycyl-sarcosine (n = 6; to determine whether competitive inhibition of Lys-Lys uptake would abolish PepT1-mediated effects). The diets provided lysine at 75% of the requirement and were gastrically delivered for a total of 18 hours. Whole-body and tissue-specific protein synthesis, as well as indices for gut structure and barrier function, were measured. RESULTS The villus height, mucosal weight, and free lysine concentration were higher in the Lys-Lys group compared to the other 2 groups (P < 0.05). Lysyl-lysine led to greater whole-body protein synthesis compared to free lysine (P < 0.05). Mucosal myeloperoxidase activity was lower in the Lys-Lys group (P < 0.05), suggesting less inflammation. The inclusion of glycyl-sarcosine with Lys-Lys abolished the dipeptide effects on whole-body and tissue-specific protein synthesis (P < 0.05), suggesting that improved lysine availability was mediated by PepT1. CONCLUSIONS Improved intestinal structure and whole-body protein synthesis suggests that feeding strategies designed to exploit PepT1 may help to avoid adverse effects when enteral nutrition is reintroduced into the compromised guts of neonatal piglets.
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Affiliation(s)
| | - Robert F Bertolo
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Janet A Brunton
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada
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Khavinson V, Linkova N, Kozhevnikova E, Dyatlova A, Petukhov M. Transport of Biologically Active Ultrashort Peptides Using POT and LAT Carriers. Int J Mol Sci 2022; 23:ijms23147733. [PMID: 35887081 PMCID: PMC9323678 DOI: 10.3390/ijms23147733] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 01/27/2023] Open
Abstract
Ultrashort peptides (USPs), consisting of 2–7 amino-acid residues, are a group of signaling molecules that regulate gene expression and protein synthesis under normal conditions in various diseases and ageing. USPs serve as a basis for the development of drugs with a targeted mechanism of action. The purpose of this review is to systematize the available data on USP transport involving POT and LAT transporters in various organs and tissues under normal, pathological and ageing conditions. The carriers of the POT family (PEPT1, PEPT2, PHT1, PHT2) transport predominantly di- and tripeptides into the cell. Methods of molecular modeling and physicochemistry have demonstrated the ability of LAT1 to transfer not only amino acids but also some di- and tripeptides into the cell and out of it. LAT1 and 2 are involved in the regulation of the antioxidant, endocrine, immune and nervous systems’ functions. Analysis of the above data allows us to conclude that, depending on their structure, di- and tripeptides can be transported into the cells of various tissues by POT and LAT transporters. This mechanism is likely to underlie the tissue specificity of peptides, their geroprotective action and effectiveness in the case of neuroimmunoendocrine system disorders.
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Affiliation(s)
- Vladimir Khavinson
- Department of Biogerontology, Saint Petersburg Institute of Bioregulation and Gerontology, 197110 Saint Petersburg, Russia; (N.L.); (E.K.); (A.D.)
- Group of Peptide Regulation of Aging, Pavlov Institute of Physiology of Russian Academy of Sciences, 199034 Saint Petersburg, Russia
- Correspondence: or ; Tel.: +7-(921)-9110800
| | - Natalia Linkova
- Department of Biogerontology, Saint Petersburg Institute of Bioregulation and Gerontology, 197110 Saint Petersburg, Russia; (N.L.); (E.K.); (A.D.)
- The Laboratory “Problems of Aging”, Belgorod National Research University, 308015 Belgorod, Russia
| | - Ekaterina Kozhevnikova
- Department of Biogerontology, Saint Petersburg Institute of Bioregulation and Gerontology, 197110 Saint Petersburg, Russia; (N.L.); (E.K.); (A.D.)
| | - Anastasiia Dyatlova
- Department of Biogerontology, Saint Petersburg Institute of Bioregulation and Gerontology, 197110 Saint Petersburg, Russia; (N.L.); (E.K.); (A.D.)
| | - Mikhael Petukhov
- Petersburg Nuclear Physics Institute Named after B.P. Konstantinov, NRC “Kurchatov Institute”, 188300 Gatchina, Russia;
- Peter the Great St. Petersburg Group of Biophysics, Higher Engineering and Technical School, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
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Pleić IL, Bušelić I, Messina M, Hrabar J, Žuvić L, Talijančić I, Žužul I, Pavelin T, Anđelić I, Pleadin J, Puizina J, Grubišić L, Tibaldi E, Šegvić-Bubić T. A plant-based diet supplemented with Hermetia illucens alone or in combination with poultry by-product meal: one step closer to sustainable aquafeeds for European seabass. J Anim Sci Biotechnol 2022; 13:77. [PMID: 35811320 PMCID: PMC9272557 DOI: 10.1186/s40104-022-00725-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/04/2022] [Indexed: 11/10/2022] Open
Abstract
Background Increasing demand for high-value fish species and pressure on forage fish is challenging aquaculture to ensure sustainable growth by replacing protein sources in aquafeeds with plant and terrestrial animal proteins, without compromising the economic value and quality of the final fish product. In the present study, the effects of a plant protein-based diet (CV), two plant-based diets in which graded amounts of plan protein mixtures were replaced with Hermetia illucens meal alone (VH10) or in combination with poultry by-product meal (PBM) (VH10P30), a fishmeal (FM) diet (CF) and an FM diet supplemented with H. illucens (FH10) on growth performance, gut health and homeostasis of farmed subadult European seabass were tested and compared. Results Fish fed the VH10 and VH10P30 diets showed the highest specific growth rates and lowest feed conversion ratios among the tested groups. Expectedly, the best preservation of PI morphology was observed in fish fed the CF or FH10 diets, while fish fed the CV diet exhibited significant degenerative changes in the proximal and distal intestines. However, PBM supplementation mitigated these effects and significantly improved all gut morphometric parameters in the VH10P30 group. Partial substitution of the plant mixture with insect meal alone or PBM also induced most BBM genes and activated BBM enzymes, suggesting a beneficial effect on intestinal digestive/absorption functions. Regarding intestinal microbiota, fish fed diets containing H. illucens meal (FH10, VH10, VH10P30) had the highest richness of bacterial communities and abundance of beneficial genera such as Lactobacillus and Bacillus. On the other hand, fish fed CV had the highest microbial diversity but lost a significant component of fish intestinal microbiota, the phylum Bacteroidetes. Finally, skin pigmentation most similar to that of farmed or even wild seabass was also observed in the fish groups fed CF, FH10 or VH10P30. Conclusion Plant-based diets supplemented with PBM and H. illucens pupae meal have great potential as alternative diets for European seabass, without affecting growth performance, gut homeostasis, or overall fitness. This also highlights the importance of animal proteins in diets of European seabass, as the addition of a small amount of these alternative animal protein sources significantly improved all measured parameters. Supplementary Information The online version contains supplementary material available at 10.1186/s40104-022-00725-z.
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Tokutake Y, Taciak M, Sato K, Toyomizu M, Kikusato M. Effect of dipeptide on intestinal peptide transporter 1 gene expression: An evaluation using primary cultured chicken intestinal epithelial cells. Anim Sci J 2021; 92:e13604. [PMID: 34309968 PMCID: PMC9285489 DOI: 10.1111/asj.13604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 06/20/2021] [Accepted: 06/28/2021] [Indexed: 12/21/2022]
Abstract
Peptide transporter 1 (PepT1) is a transporter responsible for absorbing dipeptide and tripeptide in enterocytes and is upregulated by dipeptide in mammals. It has not been certain whether intestinal PepT1 expression is responsive to dipeptides in chickens because of the lack of in vitro study using the cultured enterocytes. This study established a primary culture model of chicken intestinal epithelial cells (IECs) in two‐dimensional monolayer culture using collagen gel by which the response of chicken PepT1 gene expression to dipeptide stimuli was evaluated. The cultured chicken IECs showed the epithelial‐like morphology attached in a patch‐manner and exhibited positive expression of cytokeratin and epithelial cadherin, specific marker proteins of epithelial cells. Moreover, the chicken IECs exhibited the gene expression of intestinal cell type‐specific marker, villin1, mucin 2, and chromogranin A, suggesting that the cultured IECs were composed of enterocytes as well as goblet and enteroendocrine cells. PepT1 gene expression was significantly upregulated by synthetic dipeptide, glycyl‐l‐glutamine, in the cultured IECs. From the results, we herein suggested that dipeptide is a factor upregulating PepT1 gene expression in chicken IECs.
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Affiliation(s)
- Yukako Tokutake
- Animal Nutrition, Life Sciences, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Marcin Taciak
- Animal Nutrition, Life Sciences, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland
| | - Kan Sato
- Animal Nutrition, Life Sciences, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Masaaki Toyomizu
- Animal Nutrition, Life Sciences, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Motoi Kikusato
- Animal Nutrition, Life Sciences, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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Biolley C, Tretola M, Bee G, Jud C, Silacci P. Punicalagin increases glutamate absorption in differentiated Caco-2 cells by a mechanism involving gene expression regulation of an EAAT3 transporter. Food Funct 2019; 10:5333-5338. [PMID: 31389458 DOI: 10.1039/c9fo00191c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This study investigates, for the first time, the ability of punicalagin to modulate intestinal glutamate uptake by upregulation of the expression of one of its transporters present on the enterocyte membrane. The use of an Ussing chamber revealed an increase in glutamate transport in differentiated Caco-2 cells after punicalagin treatment for 24 h. This cell line constitutively expresses two glutamate transporters: EAAT1 and EAAT3. In response to punicalagin, the expression of EAAT3 was increased, at both mRNA and protein levels, but not that of EAAT1. Transfection with EAAT3-targeting siRNA specifically altered basal and induced EAAT3 gene expression, decreasing the positive effect of punicalagin on glutamate uptake. These data confirmed the involvement of EAAT3 in increasing glutamate uptake by enterocytes after punicalagin treatment.
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Al-Ali AAA, Nielsen RB, Steffansen B, Holm R, Nielsen CU. Nonionic surfactants modulate the transport activity of ATP-binding cassette (ABC) transporters and solute carriers (SLC): Relevance to oral drug absorption. Int J Pharm 2019; 566:410-433. [DOI: 10.1016/j.ijpharm.2019.05.033] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 05/10/2019] [Accepted: 05/11/2019] [Indexed: 01/11/2023]
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Rabbit SLC15A1, SLC7A1 and SLC1A1 genes are affected by site of digestion, stage of development and dietary protein content. Animal 2019; 13:326-332. [DOI: 10.1017/s1751731118001404] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Spanier B, Rohm F. Proton Coupled Oligopeptide Transporter 1 (PepT1) Function, Regulation, and Influence on the Intestinal Homeostasis. Compr Physiol 2018; 8:843-869. [PMID: 29687907 DOI: 10.1002/cphy.c170038] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Physiological and therapeutic regulation of glucose homeostasis by upper small intestinal PepT1-mediated protein sensing. Nat Commun 2018; 9:1118. [PMID: 29549253 PMCID: PMC5856761 DOI: 10.1038/s41467-018-03490-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 02/16/2018] [Indexed: 02/07/2023] Open
Abstract
High protein feeding improves glucose homeostasis in rodents and humans with diabetes, but the mechanisms that underlie this improvement remain elusive. Here we show that acute administration of casein hydrolysate directly into the upper small intestine increases glucose tolerance and inhibits glucose production in rats, independently of changes in plasma amino acids, insulin levels, and food intake. Inhibition of upper small intestinal peptide transporter 1 (PepT1), the primary oligopeptide transporter in the small intestine, reverses the preabsorptive ability of upper small intestinal casein infusion to increase glucose tolerance and suppress glucose production. The glucoregulatory role of PepT1 in the upper small intestine of healthy rats is further demonstrated by glucose homeostasis disruption following high protein feeding when PepT1 is inhibited. PepT1-mediated protein-sensing mechanisms also improve glucose homeostasis in models of early-onset insulin resistance and obesity. We demonstrate that preabsorptive upper small intestinal protein-sensing mechanisms mediated by PepT1 have beneficial effects on whole-body glucose homeostasis. High protein diets are known to improve metabolic parameters including adiposity and glucose homeostasis. Here the authors demonstrate that preabsorptive upper small intestinal protein-sensing mechanisms mediated by peptide transporter 1 improve glucose homeostasis by inhibiting hepatic glucose production.
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Hu QX, Ottestad-Hansen S, Holmseth S, Hassel B, Danbolt NC, Zhou Y. Expression of Glutamate Transporters in Mouse Liver, Kidney, and Intestine. J Histochem Cytochem 2018; 66:189-202. [PMID: 29303644 DOI: 10.1369/0022155417749828] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Glutamate transport activities have been identified not only in the brain, but also in the liver, kidney, and intestine. Although glutamate transporter distributions in the central nervous system are fairly well known, there are still uncertainties with respect to the distribution of these transporters in peripheral organs. Quantitative information is mostly lacking, and few of the studies have included genetically modified animals as specificity controls. The present study provides validated qualitative and semi-quantitative data on the excitatory amino acid transporter (EAAT)1-3 subtypes in the mouse liver, kidney, and intestine. In agreement with the current view, we found high EAAT3 protein levels in the brush borders of both the distal small intestine and the renal proximal tubules. Neither EAAT1 nor EAAT2 was detected at significant levels in murine kidney or intestine. In contrast, the liver only expressed EAAT2 (but 2 C-terminal splice variants). EAAT2 was detected in the plasma membranes of perivenous hepatocytes. These cells also expressed glutamine synthetase. Conditional deletion of hepatic EAAT2 did neither lead to overt neurological disturbances nor development of fatty liver.
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Affiliation(s)
- Qiu Xiang Hu
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Sigrid Ottestad-Hansen
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Silvia Holmseth
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Bjørnar Hassel
- Department of Complex Neurology and Neurohabilitation, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Niels Christian Danbolt
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Yun Zhou
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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Jando J, Camargo SMR, Herzog B, Verrey F. Expression and regulation of the neutral amino acid transporter B0AT1 in rat small intestine. PLoS One 2017; 12:e0184845. [PMID: 28915252 PMCID: PMC5600382 DOI: 10.1371/journal.pone.0184845] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 08/24/2017] [Indexed: 01/11/2023] Open
Abstract
Absorption of neutral amino acids across the luminal membrane of intestinal enterocytes is mediated by the broad neutral amino acid transporter B0AT1 (SLC6A19). Its intestinal expression depends on co-expression of the membrane-anchored peptidase angiotensin converting enzyme 2 (ACE2) and is additionally enhanced by aminopeptidase N (CD13). We investigated in this study the expression of B0AT1 and its auxiliary peptidases as well as its transport function along the rat small intestine. Additionally, we tested its possible short- and long-term regulation by dietary proteins and amino acids. We showed by immunofluorescence that B0AT1, ACE2 and CD13 co-localize on the luminal membrane of small intestinal villi and by Western blotting that their protein expression increases in distal direction. Furthermore, we observed an elevated transport activity of the neutral amino acid L-isoleucine during the nocturnal active phase compared to the inactive one. Gastric emptying was delayed by intragastric application of an amino acid cocktail but we observed no acute dietary regulation of B0AT1 protein expression and L-isoleucine transport. Investigation of the chronic dietary regulation of B0AT1, ACE2 and CD13 by different diets revealed an increased B0AT1 protein expression under amino acid-supplemented diet in the proximal section but not in the distal one and for ACE2 protein expression a reverse localization of the effect. Dietary regulation for CD13 protein expression was not as distinct as for the two other proteins. Ring uptake experiments showed a tendency for increased L-isoleucine uptake under amino acid-supplemented diet and in vivo L-isoleucine absorption was more efficient under high protein and amino acid-supplemented diet. Additionally, plasma levels of branched-chain amino acids were elevated under high protein and amino acid diet. Taken together, our experiments did not reveal an acute amino acid-induced regulation of B0AT1 but revealed a chronic dietary adaptation mainly restricted to the proximal segment of the small intestine.
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Affiliation(s)
- Julia Jando
- Institute of Physiology, Zurich Center of Integrative Human Physiology and NCCR Kidney.CH, University of Zurich, Zurich, Switzerland
| | - Simone M. R. Camargo
- Institute of Physiology, Zurich Center of Integrative Human Physiology and NCCR Kidney.CH, University of Zurich, Zurich, Switzerland
| | - Brigitte Herzog
- Institute of Physiology, Zurich Center of Integrative Human Physiology and NCCR Kidney.CH, University of Zurich, Zurich, Switzerland
| | - François Verrey
- Institute of Physiology, Zurich Center of Integrative Human Physiology and NCCR Kidney.CH, University of Zurich, Zurich, Switzerland
- * E-mail:
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Liu H, Wang J, Mou D, Che L, Fang Z, Feng B, Lin Y, Xu S, Li J, Wu D. Maternal Methyl Donor Supplementation during Gestation Counteracts the Bisphenol A-Induced Impairment of Intestinal Morphology, Disaccharidase Activity, and Nutrient Transporters Gene Expression in Newborn and Weaning Pigs. Nutrients 2017; 9:nu9050423. [PMID: 28445388 PMCID: PMC5452153 DOI: 10.3390/nu9050423] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 04/17/2017] [Accepted: 04/19/2017] [Indexed: 01/05/2023] Open
Abstract
This study was conducted to explore whether exposure to bisphenol A (BPA) during pregnancy could change intestinal digestion and absorption function in offspring using pigs as a model, and whether methyl donor (MET) could counteract the BPA-induced impacts. Fifty Landrace × Yorkshire sows were divided into four dietary groups throughout gestation: control diet (CON); control diet supplemented with BPA (50 mg/kg); control diet supplemented with MET (3 g/kg betaine, 400 mg/kg choline, 150 μg/kg vitamin B12, and 15 mg/kg folic acid); and control diet with BPA and MET supplementation (BPA + MET). Intestine samples were collected from pigs’ offspring at birth and weaning. Maternal BPA exposure during pregnancy significantly reduced the ratio of jejunum villus height to crypt depth, decreased the jejunum sucrase activity, down-regulated the mRNA expression of jejunum peptide transporter 1 (Pept1) and DNA methyl transferase 3a (DNMT3a), and decreased the DNA methylation level of jejunum Pept1 in offspring (p < 0.05). Maternal MET supplementation significantly raised the ratio of villus height to crypt depth in jejunum and ileum, improved the jejunum lactase activity, up-regulated the mRNA expression of jejunum Pept1, lactase (LCT), DNMT1, DNMT3a, and methylenetetrahydrofolate reductase (MTHFR), and increased the DNA methylation level of jejunum Pept1 in offspring (p < 0.05). However, the ratio of jejunum villus height to crypt depth was higher in BPA + MET treatment compared with CON and BPA treatment (p < 0.05). Meanwhile, there was no difference in the jejunum sucrase activity, the mRNA expression of jejunum Pept1 and DNMT3a, and the DNA methylation level of jejunum Pept1 between CON and BPA + MET treatment. These results indicated that maternal exposure to BPA during gestation might suppress offspring’s intestinal digestion and absorption function, whereas supplementation of MET could counteract these damages, which might be associated with DNA methylation.
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Affiliation(s)
- Hong Liu
- Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu 611130, China.
| | - Jun Wang
- Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu 611130, China.
| | - Daolin Mou
- Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu 611130, China.
| | - Lianqiang Che
- Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu 611130, China.
| | - Zhengfeng Fang
- Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu 611130, China.
| | - Bin Feng
- Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu 611130, China.
| | - Yan Lin
- Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu 611130, China.
| | - Shengyu Xu
- Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu 611130, China.
| | - Jian Li
- Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu 611130, China.
| | - De Wu
- Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu 611130, China.
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Wang HC, Shi FY, Hou MJ, Fu XY, Long RJ. Cloning of oligopeptide transport carrier PepT1 and comparative analysis of PepT1 messenger ribonucleic acid expression in response to dietary nitrogen levels in yak () and indigenous cattle () on the Qinghai-Tibetan plateau. J Anim Sci 2017; 94:3431-3340. [PMID: 27695788 DOI: 10.2527/jas.2016-0501] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The gastrointestinal lumen can directly absorb all di- and tripeptide protein degradation products, and oligopeptide absorption depends on the specific peptide transport carriers, which are located in gastrointestinal epithelial cells on the brush border membrane. Yak () use N more efficiently than cattle do, which implies that yak have a specific mechanism of nonprotein utilization including a peptide absorption mechanism. However, this mechanism has not been clarified. Our objective was to explore whether yak possess any adaptive mechanisms of peptide absorption to survive in the harsh foraging environment of the Qinghai-Tibetan plateau. Twelve castrated males of each of 2 genotypes, yak () and indigenous cattle (), were fed diets of various N levels. The yak PepT1 (yPepT1) cDNA was cloned in omasum epithelial tissue. Our results showed that the full-length yPepT1 cDNA contains 2,805 bp, and a 2,121-bp open reading frame encodes a putative protein of 707 AA residues. The yPepT1 AA sequence identified 5 putative extracellular N-glycosylation sites (Asn, Asn, Asn, Asn, and Asn), 2 putative intracellular protein kinase A sites (Ser and Thr), and 3 intracellular putative protein kinase C sites (Ser, Ser, and Ser). The yPepT1 AA sequence was 99, 95, 86, and 83% identical to PepT1 from cattle (), sheep (), pigs (), and humans (), respectively. The relative PepT1 mRNA expression for indigenous cattle was greater than yak in the rumen, omasum, duodenum, ileum, and liver ( < 0.001); however, it was lower in jejunum tissue ( < 0.01). The relative PepT1 mRNA expression in response to increasing dietary N for both genotypes were linear in the rumen and jejunum ( < 0.10); quadratic or cubic in the reticulum ( < 0.01); linear or quadratic in the duodenum, ileum, and liver ( ≤ 0.01); and linear, quadratic, or cubic in the omasum ( < 0.001). Moreover, there were significant interactions between genotype and dietary N in rumen, reticulum, omasum, duodenum, jejunum, ileum, and liver tissues. In conclusion, the PepT1 profile and expression in gastrointestinal epithelial cells of yak varied from those of cattle, implying that yak have evolved a peptide transport mechanism to adapt the environment of the Qinghai-Tibetan plateau.
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Di- and tripeptide transport in vertebrates: the contribution of teleost fish models. J Comp Physiol B 2016; 187:395-462. [PMID: 27803975 DOI: 10.1007/s00360-016-1044-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/12/2016] [Accepted: 10/20/2016] [Indexed: 02/06/2023]
Abstract
Solute Carrier 15 (SLC15) family, alias H+-coupled oligopeptide cotransporter family, is a group of membrane transporters known for their role in the cellular uptake of di- and tripeptides (di/tripeptides) and peptide-like molecules. Of its members, SLC15A1 (PEPT1) chiefly mediates intestinal absorption of luminal di/tripeptides from dietary protein digestion, while SLC15A2 (PEPT2) mainly allows renal tubular reabsorption of di/tripeptides from ultrafiltration, SLC15A3 (PHT2) and SLC15A4 (PHT1) possibly interact with di/tripeptides and histidine in certain immune cells, and SLC15A5 has unknown function. Our understanding of this family in vertebrates has steadily increased, also due to the surge of genomic-to-functional information from 'non-conventional' animal models, livestock, poultry, and aquaculture fish species. Here, we review the literature on the SLC15 transporters in teleost fish with emphasis on SLC15A1 (PEPT1), one of the solute carriers better studied amongst teleost fish because of its relevance in animal nutrition. We report on the operativity of the transporter, the molecular diversity, and multiplicity of structural-functional solutions of the teleost fish orthologs with respect to higher vertebrates, its relevance at the intersection of the alimentary and osmoregulative functions of the gut, its response under various physiological states and dietary solicitations, and its possible involvement in examples of total body plasticity, such as growth and compensatory growth. By a comparative approach, we also review the few studies in teleost fish on SLC15A2 (PEPT2), SLC15A4 (PHT1), and SLC15A3 (PHT2). By representing the contribution of teleost fish to the knowledge of the physiology of di/tripeptide transport and transporters, we aim to fill the gap between higher and lower vertebrates.
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Nosworthy MG, Dodge ME, Bertolo RF, Brunton JA. Enterally delivered dipeptides improve small intestinal inflammatory status in a piglet model of intestinal resection. Clin Nutr 2016; 35:852-8. [DOI: 10.1016/j.clnu.2015.05.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 04/23/2015] [Accepted: 05/24/2015] [Indexed: 11/24/2022]
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Al Hafid N, Christodoulou J. Phenylketonuria: a review of current and future treatments. Transl Pediatr 2015; 4:304-17. [PMID: 26835392 PMCID: PMC4728993 DOI: 10.3978/j.issn.2224-4336.2015.10.07] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 10/26/2015] [Indexed: 01/16/2023] Open
Abstract
Phenylketonuria (PKU) is an autosomal recessive inborn error of metabolism caused by a deficiency in the hepatic enzyme phenylalanine hydroxylase (PAH). If left untreated, the main clinical feature is intellectual disability. Treatment, which includes a low Phe diet supplemented with amino acid formulas, commences soon after diagnosis within the first weeks of life. Although dietary treatment has been successful in preventing intellectual disability in early treated PKU patients, there are major issues with dietary compliance due to palatability of the diet. Other potential issues associated with dietary therapy include nutritional deficiencies especially vitamin D and B12. Suboptimal outcomes in cognitive and executive functioning have been reported in patients who adhere poorly to dietary therapy. There have been continuous attempts at improving the quality of medical foods including their palatability. Advances in dietary therapy such as the use of large neutral amino acids (LNAA) and glycomacropeptides (GMP; found within the whey fraction of bovine milk) have been explored. Gene therapy and enzyme replacement or substitution therapy have yielded more promising data in the recent years. In this review the current and possible future treatments for PKU are discussed.
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van der Wielen N, van Avesaat M, de Wit NJW, Vogels JTWE, Troost F, Masclee A, Koopmans SJ, van der Meulen J, Boekschoten MV, Müller M, Hendriks HFJ, Witkamp RF, Meijerink J. Cross-species comparison of genes related to nutrient sensing mechanisms expressed along the intestine. PLoS One 2014; 9:e107531. [PMID: 25216051 PMCID: PMC4162619 DOI: 10.1371/journal.pone.0107531] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 08/12/2014] [Indexed: 01/29/2023] Open
Abstract
INTRODUCTION Intestinal chemosensory receptors and transporters are able to detect food-derived molecules and are involved in the modulation of gut hormone release. Gut hormones play an important role in the regulation of food intake and the control of gastrointestinal functioning. This mechanism is often referred to as "nutrient sensing". Knowledge of the distribution of chemosensors along the intestinal tract is important to gain insight in nutrient detection and sensing, both pivotal processes for the regulation of food intake. However, most knowledge is derived from rodents, whereas studies in man and pig are limited, and cross-species comparisons are lacking. AIM To characterize and compare intestinal expression patterns of genes related to nutrient sensing in mice, pigs and humans. METHODS Mucosal biopsy samples taken at six locations in human intestine (n = 40) were analyzed by qPCR. Intestinal scrapings from 14 locations in pigs (n = 6) and from 10 locations in mice (n = 4) were analyzed by qPCR and microarray, respectively. The gene expression of glucagon, cholecystokinin, peptide YY, glucagon-like peptide-1 receptor, taste receptor T1R3, sodium/glucose cotransporter, peptide transporter-1, GPR120, taste receptor T1R1, GPR119 and GPR93 was investigated. Partial least squares (PLS) modeling was used to compare the intestinal expression pattern between the three species. RESULTS AND CONCLUSION The studied genes were found to display specific expression patterns along the intestinal tract. PLS analysis showed a high similarity between human, pig and mouse in the expression of genes related to nutrient sensing in the distal ileum, and between human and pig in the colon. The gene expression pattern was most deviating between the species in the proximal intestine. Our results give new insights in interspecies similarities and provide new leads for translational research and models aiming to modulate food intake processes in man.
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Affiliation(s)
- Nikkie van der Wielen
- Top Institute Food and Nutrition, 9A, Wageningen, The Netherlands
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Mark van Avesaat
- Top Institute Food and Nutrition, 9A, Wageningen, The Netherlands
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, NUTRIM, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Nicole J. W. de Wit
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Jack T. W. E. Vogels
- Netherlands Organisation for Applied Scientific Research, TNO, Zeist, The Netherlands
| | - Freddy Troost
- Top Institute Food and Nutrition, 9A, Wageningen, The Netherlands
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, NUTRIM, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Ad Masclee
- Top Institute Food and Nutrition, 9A, Wageningen, The Netherlands
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, NUTRIM, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Sietse-Jan Koopmans
- Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands
- Animal Sciences Group, Wageningen University and Research centre, Lelystad, The Netherlands
| | - Jan van der Meulen
- Animal Sciences Group, Wageningen University and Research centre, Lelystad, The Netherlands
| | - Mark V. Boekschoten
- Top Institute Food and Nutrition, 9A, Wageningen, The Netherlands
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Michael Müller
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Henk F. J. Hendriks
- Top Institute Food and Nutrition, 9A, Wageningen, The Netherlands
- Netherlands Organisation for Applied Scientific Research, TNO, Zeist, The Netherlands
| | - Renger F. Witkamp
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Jocelijn Meijerink
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
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A high-protein formula increases colonic peptide transporter 1 activity during neonatal life in low-birth-weight piglets and disturbs barrier function later in life. Br J Nutr 2014; 112:1073-80. [DOI: 10.1017/s0007114514001901] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Dietary peptides are absorbed along the intestine through peptide transporter 1 (PepT-1) which is highly responsive to dietary protein level. PepT-1 is also involved in gut homeostasis, both initiating and resolving inflammation. Low-birth-weight (LBW) neonates are routinely fed a high-protein (HP) formula to enhance growth. However, the influence of this nutritional practice on PepT-1 activity is unknown. Intestinal PepT-1 activity was compared in normal-birth-weight (NBW) and LBW piglets. The effect of HP v. normal-protein (NP) formula feeding on PepT-1 activity and gut homeostasis in LBW piglets was evaluated, during the neonatal period and in adulthood. Flux of cephalexin (CFX) across the tissue mounted in Ussing chambers was used as an indicator of PepT-1 activity. CFX flux was greater in the ileum, but not jejunum or colon, of LBW than NBW piglets during the neonatal period. When LBW piglets were formula-fed, the HP formula increased colonic CFX during the 1st week of life. Later in life, intestinal CFX fluxes and barrier function were similar whether LBW pigs had been fed NP or HP formula. However, colonic permeability of HP- but not NP-fed pigs increased when luminal pH was brought to 6·0. The formyl peptide N-formyl methionyl-leucyl-phenylalanine conferred colonic barrier protection in HP-fed piglets. Heat shock protein 27 levels in the colonic mucosa of HP-fed LBW pigs correlated with the magnitude of response to the acidic challenge. In conclusion, feeding a HP formula enhanced colonic PepT-1 activity in LBW pig neonates and increased sensitivity of the colon to luminal stress in adulthood.
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Trivedi MS, Shah JS, Al-Mughairy S, Hodgson NW, Simms B, Trooskens GA, Van Criekinge W, Deth RC. Food-derived opioid peptides inhibit cysteine uptake with redox and epigenetic consequences. J Nutr Biochem 2014; 25:1011-8. [PMID: 25018147 DOI: 10.1016/j.jnutbio.2014.05.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 04/07/2014] [Accepted: 05/05/2014] [Indexed: 12/17/2022]
Abstract
Dietary interventions like gluten-free and casein-free diets have been reported to improve intestinal, autoimmune and neurological symptoms in patients with a variety of conditions; however, the underlying mechanism of benefit for such diets remains unclear. Epigenetic programming, including CpG methylation and histone modifications, occurring during early postnatal development can influence the risk of disease in later life, and such programming may be modulated by nutritional factors such as milk and wheat, especially during the transition from a solely milk-based diet to one that includes other forms of nutrition. The hydrolytic digestion of casein (a major milk protein) and gliadin (a wheat-derived protein) releases peptides with opioid activity, and in the present study, we demonstrate that these food-derived proline-rich opioid peptides modulate cysteine uptake in cultured human neuronal and gastrointestinal (GI) epithelial cells via activation of opioid receptors. Decreases in cysteine uptake were associated with changes in the intracellular antioxidant glutathione and the methyl donor S-adenosylmethionine. Bovine and human casein-derived opioid peptides increased genome-wide DNA methylation in the transcription start site region with a potency order similar to their inhibition of cysteine uptake. Altered expression of genes involved in redox and methylation homeostasis was also observed. These results illustrate the potential of milk- and wheat-derived peptides to exert antioxidant and epigenetic changes that may be particularly important during the postnatal transition from placental to GI nutrition. Differences between peptides derived from human and bovine milk may contribute to developmental differences between breastfed and formula-fed infants. Restricted antioxidant capacity, caused by wheat- and milk-derived opioid peptides, may predispose susceptible individuals to inflammation and systemic oxidation, partly explaining the benefits of gluten-free or casein-free diets.
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Affiliation(s)
- Malav S Trivedi
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Jayni S Shah
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Sara Al-Mughairy
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Nathaniel W Hodgson
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Benjamin Simms
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Geert A Trooskens
- Department of Mathematical Modelling, Statistics and Bioinformatics, Faculty of Bioscience Engineering, Ghent University, Ghent 9000, Belgium
| | - Wim Van Criekinge
- Department of Mathematical Modelling, Statistics and Bioinformatics, Faculty of Bioscience Engineering, Ghent University, Ghent 9000, Belgium
| | - Richard C Deth
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA.
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Enhanced intestinal permeability and oral bioavailability of enalapril maleate upon complexation with the cationic polymethacrylate Eudragit E100. Eur J Pharm Sci 2014; 55:1-11. [DOI: 10.1016/j.ejps.2014.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 12/28/2013] [Accepted: 01/09/2014] [Indexed: 11/17/2022]
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Do TTH, Hindlet P, Waligora-Dupriet AJ, Kapel N, Neveux N, Mignon V, Deloménie C, Farinotti R, Fève B, Buyse M. Disturbed intestinal nitrogen homeostasis in a mouse model of high-fat diet-induced obesity and glucose intolerance. Am J Physiol Endocrinol Metab 2014; 306:E668-80. [PMID: 24425764 DOI: 10.1152/ajpendo.00437.2013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The oligopeptide transporter peptide cotransporter-1 Slc15a1 (PEPT1) plays a major role in the regulation of nitrogen supply, since it is responsible for 70% of the dietary nitrogen absorption. Previous studies demonstrated that PEPT1 expression and function in jejunum are reduced in diabetes and obesity, suggesting a nitrogen malabsorption from the diet. Surprisingly, we reported here a decrease in gut nitrogen excretion in high-fat diet (HFD)-fed mice and further investigated the mechanisms that could explain this apparent contradiction. Upon HFD, mice exhibited an increased concentration of free amino acids (AAs) in the portal vein (60%) along with a selective increase in the expression of two AA transporters (Slc6a20a, Slc36a1), pointing to a specific and adaptive absorption of some AAs. A delayed transit time (+40%) and an increased intestinal permeability (+80%) also contribute to the increase in nitrogen absorption. Besides, HFD mice exhibited a 2.2-fold decrease in fecal DNA resulting from a reduction in nitrogen catabolism from cell desquamation and/or in the intestinal microbiota. Indeed, major quantitative (2.5-fold reduction) and qualitative alterations of intestinal microbiota were observed in feces of HFD mice. Collectively, our results strongly suggest that both increased AA transporters, intestinal permeability and transit time, and changes in gut microbiota are involved in the increased circulating AA levels. Modifications in nitrogen homeostasis provide a new insight in HFD-induced obesity and glucose intolerance; however, whether these modifications are beneficial or detrimental for the HFD-associated metabolic complications remains an open issue.
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Affiliation(s)
- Thi Thu Huong Do
- Université Pierre et Marie Curie, Paris, Unité Mixte de Recherche S938, Paris, France
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Abstract
In vertebrates and invertebrates, morphological and functional features of gastrointestinal (GI) tracts generally reflect food chemistry, such as content of carbohydrates, proteins, fats, and material(s) refractory to rapid digestion (e.g., cellulose). The expression of digestive enzymes and nutrient transporters approximately matches the dietary load of their respective substrates, with relatively modest excess capacity. Mechanisms explaining differences in hydrolase activity between populations and species include gene copy number variations and single-nucleotide polymorphisms. Transcriptional and posttranscriptional adjustments mediate phenotypic changes in the expression of hydrolases and transporters in response to dietary signals. Many species respond to higher food intake by flexibly increasing digestive compartment size. Fermentative processes by symbiotic microorganisms are important for cellulose degradation but are relatively slow, so animals that rely on those processes typically possess special enlarged compartment(s) to maintain a microbiota and other GI structures that slow digesta flow. The taxon richness of the gut microbiota, usually identified by 16S rRNA gene sequencing, is typically an order of magnitude greater in vertebrates than invertebrates, and the interspecific variation in microbial composition is strongly influenced by diet. Many of the nutrient transporters are orthologous across different animal phyla, though functional details may vary (e.g., glucose and amino acid transport with K+ rather than Na+ as a counter ion). Paracellular absorption is important in many birds. Natural toxins are ubiquitous in foods and may influence key features such as digesta transit, enzymatic breakdown, microbial fermentation, and absorption.
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Affiliation(s)
- William H Karasov
- Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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25
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Foster DR, Yee S, Bleske BE, Carver PL, Shea MJ, Menon SS, Ramachandran C, Welage LS, Amidon GL. Lack of Interaction Between the Peptidomimetic Substrates Captopril and Cephradine. J Clin Pharmacol 2013; 49:360-7. [DOI: 10.1177/0091270008329554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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26
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Ontogeny of dipeptide uptake and peptide transporter 1 (PepT1) expression along the gastrointestinal tract in the neonatal Yucatan miniature pig. Br J Nutr 2012; 110:275-81. [DOI: 10.1017/s0007114512005041] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The H+-coupled transporter, peptide transporter 1 (PepT1), is responsible for the uptake of dietary di- and tripeptides in the intestine. Using an in vivo continuously perfused gut loop model in Yucatan miniature pigs, we measured dipeptide disappearance from four 10 cm segments placed at equidistant sites along the length of the small intestine. Pigs were studied at 1, 2, 3 (suckling) and 6 weeks (post-weaning) postnatal age. Transport capability across the PepT1 transporter was assessed by measuring the disappearance of 3H-glycylsarcosine; real-time RT-PCR was also used to quantify PepT1 mRNA. Each of the regions of intestine studied demonstrated the capacity for dipeptide transport. There were no differences among age groups in transport rates measured in the most proximal intestine segment. Transport of 3H-glycylsarcosine was significantly higher in the ileal section in the youngest age group (1 week) compared with the other the suckling groups; however, all suckling piglet groups demonstrated lower ileal transport compared with the post-weaned pigs. Colonic PepT1 mRNA was maximal in the earliest weeks of development and decreased to its lowest point by week 6. These results suggest that peptide transport in the small intestine may be of importance during the first week of suckling and again with diet transition following weaning.
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27
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Liu Z, Zhou Y, Feng J, Lu S, Zhao Q, Zhang J. Characterization of oligopeptide transporter (PepT1) in grass carp (Ctenopharyngodon idella). Comp Biochem Physiol B Biochem Mol Biol 2012; 164:194-200. [PMID: 23219926 DOI: 10.1016/j.cbpb.2012.11.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 11/19/2012] [Accepted: 11/26/2012] [Indexed: 01/07/2023]
Abstract
The oligopeptide transporter (PepT1) is located on the brush-border membrane of the intestinal epithelium, and plays an important role in dipeptide and tripeptide absorptions from protein digestion. In this study, we cloned the PepT1 cDNA from grass carp and characterized its expression profile in response to dietary protein and feed additives (sodium butyrate) treatments. The PepT1 gene encodes a protein of 714 amino acids with high sequence similarity with other vertebrate homologues. Expression analysis revealed highest levels of PepT1 mRNA expression in the foregut of grass carp. In addition, PepT1 mRNA expression exhibited diurnal variation in all three bowel segments of intestine with lower levels of expression in daytime than nighttime. During embryonic development, PepT1 showed a dynamic pattern of expression reaching maximal levels of expression in the gastrula stage and minimal levels in the organ stage. The PepT1 expression showed constant levels from 14 to 34 day post-hatch. To determine whether fish diet of different protein contents may have any effect on PepT1 expression, we extended our research to dietary regulation of PepT1 expression. We found that dietary protein levels had a significant effect on PepT1 gene expression. In addition, PepT1 mRNA levels were higher after feeding with fish meal than with soybean meal. Moreover, in vitro and in vivo sodium butyrate treatments increased PepT1 expression in the intestine of grass carp. The results demonstrate for the first time that PepT1 mRNA expression is regulated in a temporal and spatial pattern during development, and dietary protein and feed additives had a significant effects on PepT1 gene expression in grass carp.
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Affiliation(s)
- Zhen Liu
- Department of Biotechnology and Environmental Science, Changsha University, Changsha 410003, China
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28
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Nerveless and gutsy: intestinal nutrient sensing from invertebrates to humans. Semin Cell Dev Biol 2012; 23:614-20. [PMID: 22248674 PMCID: PMC3712190 DOI: 10.1016/j.semcdb.2012.01.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 12/27/2011] [Accepted: 01/04/2012] [Indexed: 12/22/2022]
Abstract
The increasingly recognized role of gastrointestinal signals in the regulation of food intake, insulin production and peripheral nutrient storage has prompted a surge of interest in studying how the gastrointestinal tract senses and responds to nutritional information. Identification of metabolically important intestinal nutrient sensors could provide potential new drug targets for the treatment of diabetes, obesity and gastrointestinal disorders. From a more fundamental perspective, the study of intestinal chemosensation is revealing novel, non-neuronal modes of communication involving differentiated epithelial cells. It is also identifying signalling mechanisms downstream of not only canonical receptors but also nutrient transporters, thereby supporting a chemosensory role for “transceptors” in the intestine. This review describes known and proposed mechanisms of intestinal carbohydrate, protein and lipid sensing, best characterized in mammalian systems. It also highlights the potential of invertebrate model systems such as C. elegans and Drosophila melanogaster by summarizing known examples of molecular evolutionary conservation. Recently developed genetic tools in Drosophila, an emerging model system for the study of physiology and metabolism, allow the temporal, spatial and high-throughput manipulation of putative intestinal sensors. Hence, fruit flies may prove particularly suited to the study of the link between intestinal nutrient sensing and metabolic homeostasis.
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29
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Madsen SL, Wong EA. Expression of the chicken peptide transporter 1 and the peroxisome proliferator-activated receptor α following feed restriction and subsequent refeeding. Poult Sci 2011; 90:2295-300. [PMID: 21934013 DOI: 10.3382/ps.2010-01173] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The peptide transporter 1 (PepT1) transports di- and tripeptides from the lumen of the small intestine into the enterocyte. Expression of this transporter is affected by numerous factors, including feed restriction. During a fasting state, PepT1 is thought to be regulated by peroxisome proliferator-activated receptor α (PPARα). The objective of this study was to evaluate the effects of a feed restriction-refeeding regimen on expression of chicken PepT1 and PPARα. Ten-day-old broiler chicks were placed on a 24-h feed restriction with 6 birds sampled before and after the restriction. Following feed restriction, the remaining birds were divided into 3 groups: continuously fasted, refed-food withdrawn, and refed ad libitum. The duodenum, jejunum, and ileum were sampled 1, 2, 3, 5, and 7 h post feed restriction. Expression of PepT1 and PPARα increased almost 2-fold post feed restriction (P < 0.002). A significant group × time interaction was observed for PPARα, with the continuously fasted group showing a peak at 29 h postrestriction (P = 0.002). A group × segment interaction was found for both PepT1 (P = 0.002) and PPARα (P = 0.01); within the continuously fasted group, PepT1 expression was greatest in the jejunum (P < 0.001) and ileum (P = 0.01) when compared with the duodenum. No difference was observed between the jejunum and ileum. The PPARα expression was greatest in the jejunum (P = 0.03) when compared with the duodenum, with no difference between the jejunum and ileum or between the duodenum and ileum. The increase in PepT1 expression during a time of reduced feed intake suggests the importance of having transporters ready to scavenge any available luminal nutrients. The concurrent increase in PPARα suggests a possible regulatory role for this receptor in the regulation of PepT1 during feed restriction.
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Affiliation(s)
- S L Madsen
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, USA
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Nässl AM, Rubio-Aliaga I, Sailer M, Daniel H. The intestinal peptide transporter PEPT1 is involved in food intake regulation in mice fed a high-protein diet. PLoS One 2011; 6:e26407. [PMID: 22031831 PMCID: PMC3198773 DOI: 10.1371/journal.pone.0026407] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 09/26/2011] [Indexed: 01/04/2023] Open
Abstract
High-protein diets are effective in achieving weight loss which is mainly explained by increased satiety and thermogenic effects. Recent studies suggest that the effects of protein-rich diets on satiety could be mediated by amino acids like leucine or arginine. Although high-protein diets require increased intestinal amino acid absorption, amino acid and peptide absorption has not yet been considered to contribute to satiety effects. We here demonstrate a novel finding that links intestinal peptide transport processes to food intake, but only when a protein-rich diet is provided. When mice lacking the intestinal peptide transporter PEPT1 were fed diets containing 8 or 21 energy% of protein, no differences in food intake and weight gain were observed. However, upon feeding a high-protein (45 energy%) diet, Pept1(-/-) mice reduced food intake much more pronounced than control animals. Although there was a regain in food consumption after a few days, no weight gain was observed which was associated with a reduced intestinal energy assimilation and increased fecal energy losses. Pept1(-/-) mice on high-protein diet displayed markedly reduced plasma leptin levels during the period of very low food intake, suggesting a failure of leptin signaling to increase energy intake. This together with an almost two-fold elevated plasma arginine level in Pept1(-/-) but not wildtype mice, suggests that a cross-talk of arginine with leptin signaling in brain, as described previously, could cause these striking effects on food intake.
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Affiliation(s)
- Anna-Maria Nässl
- ZIEL Research Center of Nutrition and Food Sciences, Abteilung Biochemie, Technische Universität München, Freising, Germany
| | - Isabel Rubio-Aliaga
- ZIEL Research Center of Nutrition and Food Sciences, Abteilung Biochemie, Technische Universität München, Freising, Germany
| | - Manuela Sailer
- ZIEL Research Center of Nutrition and Food Sciences, Abteilung Biochemie, Technische Universität München, Freising, Germany
| | - Hannelore Daniel
- ZIEL Research Center of Nutrition and Food Sciences, Abteilung Biochemie, Technische Universität München, Freising, Germany
- * E-mail:
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Intestinal gene expression in pigs: effects of reduced feed intake during weaning and potential impact of dietary components. Nutr Res Rev 2011; 24:155-75. [DOI: 10.1017/s0954422411000047] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The weaning transition is characterised by morphological, histological and microbial changes, often leading to weaning-associated disorders. These intestinal changes can partly be ascribed to the lack of luminal nutrition arising from the reduced feed intake common in pigs after weaning. It is increasingly becoming clear that changes in the supply with enteral nutrients may have major impacts on intestinal gene expression. Furthermore, the major dietary constituents, i.e. carbohydrates, fatty acids and amino acids, participate in the regulation of intestinal gene expression. However, nutrients may also escape digestion by mammalian enzymes in the upper gastrointestinal tract. These nutrients can be used by the microflora, resulting in the production of bacterial metabolites, for example, SCFA, which may affect intestinal gene expression indirectly. The present review provides an insight on possible effects of reduced feed intake on intestinal gene expression, as it may occur post-weaning. Detailed knowledge on effects of reduced feed intake on intestinal gene expression may help to understand weaning-associated intestinal dysfunctions and diseases. Examples are given of intestinal genes which may be altered in their expression due to supply with specific nutrients. In that way, gene expression could be modulated by dietary means, thereby acting as a potential therapeutic tool. This could be achieved, for example, by influencing genes coding for digestive or absorptive proteins, thus optimising digestive function and metabolism, but also with regard to immune response, or by influencing proliferative processes, thereby enhancing mucosal repair. This would be of special interest when designing a diet to overcome weaning-associated problems.
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Cedernaes J, Olszewski PK, Almén MS, Stephansson O, Levine AS, Fredriksson R, Nylander O, Schiöth HB. Comprehensive analysis of localization of 78 solute carrier genes throughout the subsections of the rat gastrointestinal tract. Biochem Biophys Res Commun 2011; 411:702-7. [DOI: 10.1016/j.bbrc.2011.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 07/02/2011] [Indexed: 01/07/2023]
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Mourad FH, Saadé NE. Neural regulation of intestinal nutrient absorption. Prog Neurobiol 2011; 95:149-62. [PMID: 21854830 DOI: 10.1016/j.pneurobio.2011.07.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 04/28/2011] [Accepted: 07/20/2011] [Indexed: 12/17/2022]
Abstract
The nervous system and the gastrointestinal (GI) tract share several common features including reciprocal interconnections and several neurotransmitters and peptides known as gut peptides, neuropeptides or hormones. The processes of digestion, secretion of digestive enzymes and then absorption are regulated by the neuro-endocrine system. Luminal glucose enhances its own absorption through a neuronal reflex that involves capsaicin sensitive primary afferent (CSPA) fibres. Absorbed glucose stimulates insulin release that activates hepatoenteric neural pathways leading to an increase in the expression of glucose transporters. Adrenergic innervation increases glucose absorption through α1 and β receptors and decreases absorption through activation of α2 receptors. The vagus nerve plays an important role in the regulation of diurnal variation in transporter expression and in anticipation to food intake. Vagal CSPAs exert tonic inhibitory effects on amino acid absorption. It also plays an important role in the mediation of the inhibitory effect of intestinal amino acids on their own absorption at the level of proximal or distal segment. However, chronic extrinsic denervation leads to a decrease in intestinal amino acid absorption. Conversely, adrenergic agonists as well as activation of CSPA fibres enhance peptides uptake through the peptide transporter PEPT1. Finally, intestinal innervation plays a minimal role in the absorption of fat digestion products. Intestinal absorption of nutrients is a basic vital mechanism that depends essentially on the function of intestinal mucosa. However, intrinsic and extrinsic neural mechanisms that rely on several redundant loops are involved in immediate and long-term control of the outcome of intestinal function.
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Affiliation(s)
- Fadi H Mourad
- Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
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Boudry G, David ES, Douard V, Monteiro IM, Le Huërou-Luron I, Ferraris RP. Role of intestinal transporters in neonatal nutrition: carbohydrates, proteins, lipids, minerals, and vitamins. J Pediatr Gastroenterol Nutr 2010; 51:380-401. [PMID: 20808244 DOI: 10.1097/mpg.0b013e3181eb5ad6] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
To support rapid growth and a high metabolic rate, infants require enormous amounts of nutrients. The small intestine must have the complete array of transporters that absorb the nutrients released from digested food. Failure of intestinal transporters to function properly often presents symptoms as "failure to thrive" because nutrients are not absorbed and as diarrhea because unabsorbed nutrients upset luminal osmolality or become substrates of intestinal bacteria. We enumerate the nutrients that constitute human milk and various infant milk formulas, explain their importance in neonatal nutrition, then describe for each nutrient the transporter(s) that absorbs it from the intestinal lumen into the enterocyte cytosol and from the cytosol to the portal blood. More than 100 membrane and cytosolic transporters are now thought to facilitate absorption of minerals and vitamins as well as products of digestion of the macronutrients carbohydrates, proteins, and lipids. We highlight research areas that should yield information needed to better understand the important role of these transporters during normal development.
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Affiliation(s)
- Gaëlle Boudry
- Institut National de Recherche Agronomique, UMR1079 Système d'Elevage, Nutrition, Animale et Humaine, St-Gilles, France
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Dietary protein hydrolysates and free amino acids affect the spatial expression of peptide transporter PepT1 in the digestive tract of Atlantic cod (Gadus morhua). Comp Biochem Physiol B Biochem Mol Biol 2010; 156:48-55. [PMID: 20144729 DOI: 10.1016/j.cbpb.2010.02.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2009] [Revised: 01/26/2010] [Accepted: 02/01/2010] [Indexed: 02/06/2023]
Abstract
The effects of dietary inclusions of size-fractionated peptides and free amino acids (FAAs) on Peptide Transporter 1 (PepT1) mRNA levels were assessed along the length of the intestine of juvenile Atlantic cod (Gadus morhua). Five groups of fish (10-15g) were fed for 46days on diets containing approximately 42% protein, provided either as fish meal (FM, control diet) or as a combination of FM with whole fish hydrolysate (FH), retenate after ultrafiltration of FH (UFR), nanofiltered retenate of FH (NFR), or a mix of FAAs, at a 30% level of FM substitution. PepT1 mRNA expression was assessed in pyloric caeca (S1) and the remainder of the intestine divided into four equally long segments (S2-S5). PepT1 transcripts were found in all segments, indicating that the whole intestine is involved in peptide absorption. Differences in the regional expression profile of PepT1 were found. Under control diet (FM diet) conditions, fish exhibited a reduced expression in S5 compared to S2. In fish fed FAA and UFR diets, PepT1 mRNA levels were higher in S2 and S3 compared to other regions. These data suggest that PepT1 may be variably recruited along the whole intestine, including the most distal part, in response to changes in the luminal protein source content. This adaptive response might be functional to keep a maximal efficiency of protein absorption at the intestinal level.
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Qandeel HG, Alonso F, Hernandez DJ, Duenes JA, Zheng Y, Scow JS, Sarr MG. Role of vagal innervation in diurnal rhythm of intestinal peptide transporter 1 (PEPT1). J Gastrointest Surg 2009; 13:1976-85. [PMID: 19707837 PMCID: PMC2830643 DOI: 10.1007/s11605-009-0984-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Accepted: 07/24/2009] [Indexed: 01/31/2023]
Abstract
BACKGROUND Protein is absorbed predominantly as di/tripeptides via H(+)/peptide cotransporter-1 (PEPT1). We demonstrated previously diurnal variations in expression and function of duodenal and jejunal but not ileal PEPT1; neural regulation of this pattern is unexplored. HYPOTHESIS Complete abdominal vagotomy abolishes diurnal variations in gene expression and transport function of PEPT1. METHODS Twenty-four rats maintained in a 12-h light/dark room [6AM-6PM] underwent abdominal vagotomy; 24 other rats were controls. Four weeks later, mucosal levels of mRNA and protein were measured at 9AM, 3PM, 9PM, and 3AM (n = 6 each) by quantitative real-time PCR and Western blots, respectively; transporter-mediated uptake of dipeptide (Gly-Sar) was measured by the everted-sleeve technique. RESULTS Diurnal variation in mRNA, as in controls, was retained post-vagotomy in duodenum and jejunum (peak at 3PM, p < 0.05) but not in ileum. Diurnal variations in expression of protein and Gly-Sar uptake, however, were absent post-vagotomy (p > 0.3). Similar to controls, maximal uptake was in jejunum after vagotomy (V (max), nmol/cm/min: jejunum vs. duodenum and ileum; 163 vs. 88 and 71 at 3AM; p < 0.04); K (m) remained unchanged. CONCLUSIONS Vagal innervation appears to mediate in part diurnal variations in protein expression and transport function of PEPT1, but not diurnal variation in mRNA expression of PEPT1.
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Affiliation(s)
- Hisham G Qandeel
- Gastrointestinal Research Unit and Department of Surgery, Mayo Clinic, 200 1st Street SW, Rochester, MN 55905, USA
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Raybould HE. Nutrient sensing in the gastrointestinal tract: possible role for nutrient transporters. J Physiol Biochem 2009; 64:349-56. [PMID: 19391461 DOI: 10.1007/bf03174091] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Although it is well established that the presence of nutrients in the gut lumen can bring about changes in GI function, the mechanisms and pathways by which these changes occur has not been fully elucidated. It has been known for many years that luminal nutrients stimulate the release of hormones and regulatory peptides from gut endocrine cells and that luminal nutrients activate intrinsic and extrinsic neural pathways innervating the gut. Activation of gut endocrine cells and neural pathways by nutrients in the gut lumen is key in coordination of postprandial GI function and also in the regulation of food intake. Recent evidence suggests that these pathways can be modified by long term changes in diet or by inflammatory processes in the gut wall. Thus it is important to determine the cellular and molecular mechanisms underlying these processes not only to increase our understanding of as part of basic physiology but also to understand changes in these pathways that occur in the presence of pathophysiology and disease. This review summarizes some of the latest data that we have obtained, together with information from the other laboratories, which have elucidated some of the mechanisms involved in nutrient detection in the gut wall. The focus is on monosaccharides and protein hydrolysates as there is some evidence for a role for nutrient transporters in detection of these nutrients.
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Affiliation(s)
- H E Raybould
- Dept. Anatomy, Physiology and Cell Biology, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA.
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Qandeel HG, Duenes JA, Zheng Y, Sarr MG. Diurnal expression and function of peptide transporter 1 (PEPT1). J Surg Res 2009; 156:123-8. [PMID: 19577760 DOI: 10.1016/j.jss.2009.03.052] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 02/13/2009] [Accepted: 03/22/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND Protein is absorbed primarily as di/tripeptides, which are transported into the enterocyte exclusively by H(+)/peptide cotransporter 1 (PEPT1). Diurnal changes in expression and function of several other mucosal transporters occur in rat. Diurnal variations in mRNA, protein, and transport function of PEPT1 occur in rat duodenum and jejunum, but not in ileum. METHODS Mucosal levels of mRNA and protein were determined at 9 AM, 3 PM, 9 PM, and 3 AM (n=6 each) by real time RT-PCR and Western blotting, respectively, in rats maintained in a 12-h light/dark room [light 6 AM to 6 PM]; transporter-mediated uptake of dipeptide (Gly-Sar) was also measured by everted sleeve technique. RESULTS mRNA transcripts of PEPT1 and Gly-Sar uptake varied diurnally in duodenum and jejunum (peak at 3 PM, P<0.05), but not in ileum; maximal uptake was in jejunum. V(max) (nmol/cm/min) was greater at 3 PM and 9 PM compared with 9 AM (3 PM versus 9 AM: 104 versus 62 in duodenum, and 185 versus 101 in jejunum; P<0.03); K(m) was unchanged across time points or locations. Protein levels varied minimally in jejunum and ileum with peaks at 9 PM and 3 AM. CONCLUSION Gene expression and transport function of PEPT1 vary diurnally in duodenum and jejunum in temporal association with nocturnal feeding of rats.
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Affiliation(s)
- Hisham G Qandeel
- Gastroenterology Research Unit and Department of Surgery, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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Rubio-Aliaga I, Daniel H. Peptide transporters and their roles in physiological processes and drug disposition. Xenobiotica 2008; 38:1022-42. [PMID: 18668438 DOI: 10.1080/00498250701875254] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
1. The peptide transporters belong to the peptide transporter (PTR) family and serve as integral membrane proteins for the cellular uptake of di- and tripeptides in the organism. By their ability also to transport peptidomimetics and other substrates with therapeutic activities or precursors of pharmacologically active agents, they are of considerable importance in pharmacology. 2. PEPT1 is the low-affinity, high-capacity transporter and is mainly expressed in the small intestine, whereas PEPT2 is the high-affinity, low-capacity transporter and has a broader distribution in the organism. 3. Targeted mouse models have revealed PEPT2 to be the dominant transporter for the reabsorption of di- and tripeptides and its pharmacological substrates in the organism, and for the removal of these substrates from the cerebrospinal fluid. Moreover, the peptide transporters undergo physiological and pharmacological regulation and, of great interest, are present in disease states where PEPT1 exhibits ectopic expression in colonic inflammation. 4. The paper reviews the structural characteristics of the peptide transporters, the structural requirements for substrates, the distribution of the peptide transporters in the organism, and finally their regulation in the organism in healthy and pathological situations.
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Affiliation(s)
- I Rubio-Aliaga
- Molecular Nutrition Unit, Technical University of Munich, Freising-Weihenstephan, Germany
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Frazier S, Ajiboye K, Olds A, Wyatt T, Luetkemeier ES, Wong EA. Functional Characterization of the Chicken Peptide Transporter 1 (Pept1, Slc15a1) Gene. Anim Biotechnol 2008; 19:201-10. [DOI: 10.1080/10495390802240206] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Nolles JA, Peeters IGS, Bremer BI, Moorman R, Koopmanschap RE, Verstegen MWA, Schreurs VVAM. Dietary amino acids fed in free form or as protein do differently affect amino acid absorption in a rat everted sac model. J Anim Physiol Anim Nutr (Berl) 2008; 92:529-37. [DOI: 10.1111/j.1439-0396.2007.00743.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hironaka T, Itokawa S, Ogawara KI, Higaki K, Kimura T. Quantitative evaluation of PEPT1 contribution to oral absorption of cephalexin in rats. Pharm Res 2008; 26:40-50. [PMID: 18784906 DOI: 10.1007/s11095-008-9703-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Accepted: 08/05/2008] [Indexed: 10/21/2022]
Abstract
PURPOSE PEPT1 mediates the intestinal absorption of many drugs, but its contribution to oral absorption of drugs is still controversial. The objective of this study is to quantitatively evaluate the contribution of PEPT1 to oral absorption of cephalexin, a typical substrate for PEPT1, in rats. MATERIALS AND METHODS The absorbability of cephalexin via PEPT1 or passive diffusion was assessed in five intestinal segments by utilizing glycyl-proline as a competitive inhibitor by in-situ closed loop method. Absorption kinetics of cephalexin after oral administration was predicted by GI-Transit-Absorption model. RESULTS Absorbability of cephalexin was segment-dependent, and concentration-dependent in all the segments except for the lower ileum. Intrinsic absorption rate constant via PEPT1 ranged from 0.64 to 4.07 h(-1). The absorption rate constants via passive diffusion ranged from 0.78 to 1.24 h(-1). Plasma concentration-time profile of cephalexin was successfully predicted and the substantial contribution of PEPT1 to the oral absorption was calculated to be from 46% to 60% of total absorption. Simulation study indicated that 83% bioavailability would be expected for cephalexin even though PEPT1 does not function. CONCLUSIONS PEPT1 substantially contributes to oral absorption of cephalexin, around a half of total absorption. However, the function of PEPT1 can be compensated by passive diffusion for cephalexin.
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Affiliation(s)
- Takanori Hironaka
- Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Okayama, 700-8530, Japan
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Lafforgue G, Arellano C, Vachoux C, Woodley J, Philibert C, Dupouy V, Bousquet-Mélou A, Gandia P, Houin G. Oral absorption of ampicillin: role of paracellular route vs. PepT1 transporter. Fundam Clin Pharmacol 2008; 22:189-201. [PMID: 18353114 DOI: 10.1111/j.1472-8206.2008.00572.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The beta-lactam antibiotic ampicillin has a relatively poor oral bioavailability in animals and man (30-40%), and its widespread agricultural use in livestock may be contributing to the emergence of antibiotic resistance in the environment. The aim of this study was to define the absorption mechanism by which ampicillin crosses the small intestinal epithelium. The improved rat everted gut sac system was used, with an emphasis on the role of the PepT1 transporter. The absorption kinetics, effects of pH and the use of competitive substrates failed to provide any substantive evidence that the transporter played a major role in ampicillin absorption. Ethylenediaminetetraacetic acid enhanced the absorption, and tissue levels remained low, suggesting that paracellular transport was predominant. pH and competition studies with glycylsarcosine, the widely used PepT1 substrate, also failed to show any transporter activity. Despite evidence from studies with Caco-2 cells that beta-lactam antibiotics are transported by the PepT1 transporter in rat small intestine, the results rather suggest that paracellular diffusion is the major mechanism of absorption, at least for beta-lactam antibiotics with poor bioavailability, such as ampicillin. We suggest that the use of Caco-2 cells underestimates the role of the paracellular route in the absorption of hydrophilic drugs in vivo, and may exaggerate the role of influx transporters.
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Affiliation(s)
- Guylène Lafforgue
- Laboratoire Cinétique des Xénobiotiques, Faculté des Sciences Pharmaceutiques, 35 Chemin des Maraîchers, 31062 Toulouse cedex 4, France
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Li K, Xu L, Kulkarni AA, Perkins DI, Haworth IS, Davies DL. Ethanol inhibits functional activity of the human intestinal dipeptide transporter hPepT1 expressed in Xenopus oocytes. Alcohol Clin Exp Res 2008; 32:777-84. [PMID: 18336632 DOI: 10.1111/j.1530-0277.2008.00636.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The pathological effects of high alcohol (ethanol) consumption on gastrointestinal and hepatic systems are well recognized. However, the effects of ethanol intake on gastric and intestinal absorption and transport systems remain unclear. The present study investigates the effects of ethanol on the human peptide transporter 1 (hPepT1) which mediates the transport of di-and tripeptides as well as several orally administered peptidomimetic drugs such as beta-lactam antibiotics (e.g., penicillin), angiotensin-converting enzyme inhibitors, the anti-neoplastic agent bestatin, and prodrugs of acyclovir. METHODS Xenopus oocytes were injected with hPepT1 cRNA and incubated for 3 to 10 days. Currents induced by glycyl-sarcosine (Gly-Sar), Ala-Ala (dipeptides), penicillin and enalapril measured in the presence or absence of ethanol were determined using an 8-channel 2-electrode voltage clamp system, with a membrane potential of -70 mV and 11 voltage steps of 100 milliseconds (from +50 mV to -150 mV in -20 mV increments). RESULTS Ethanol (200 mM) inhibited Gly-Sar and Ala-Ala currents by 42 and 30%, respectively, with IC(50)s of 184 and 371 mM, respectively. Ethanol reduced maximal transport capacity (I(max)) of hPepT1 for Gly-Sar without affecting Gly-Sar binding affinity (K(0.5) and Hill coefficient). Penicillin- and enalapril-induced currents were significantly less than those induced by dipeptides and were not inhibited by ethanol. CONCLUSION Ethanol significantly reduced transport of dipeptides via a reduction in transport capacity, rather than competing for binding sites in hPepT1. Ethanol inhibition or alteration of transport function may be a primary causative factor contributing to both the nutritional deficits as well as the immunological deficiencies that many alcoholics experience including alcohol liver disease and brain damage.
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Affiliation(s)
- Kaixun Li
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90033, USA.
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Terada T, Inui KI. Gene expression and regulation of drug transporters in the intestine and kidney. Biochem Pharmacol 2007; 73:440-9. [PMID: 17137557 DOI: 10.1016/j.bcp.2006.10.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2006] [Revised: 10/06/2006] [Accepted: 10/09/2006] [Indexed: 01/09/2023]
Abstract
Intestinal absorption and renal secretion of ionic drugs are controlled by a number of drug transporters expressed at the brush-border and basolateral membranes of epithelial cells. Over the last several years, considerable progress has been made regarding the molecular identification and functional characterization of drug transporters. Under some physiological and pathophysiological conditions, the expression and transport activity of drug transporters are changed, affecting the pharmacokinetics of substrate drugs. The regulation of transport activity in response to endogenous and exogenous signals can occur at various levels such as transcription, mRNA stability, translation, and posttranslational modification. Transcriptional regulation is of particular interest, because changes in transport activity are dynamically regulated by increases or decreases in levels of mRNA expression. The tissue-specific expression of drug transporters is also under transcriptional control, and recent studies using clinical samples from human tissues have revealed the expression profiles of drug transporters in the human body. The purpose of this research updates is to review the recent progress in the study of the gene expression and regulation of intestinal and renal drug transporters.
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Affiliation(s)
- Tomohiro Terada
- Department of Pharmacy, Kyoto University Hospital, Kyoto 606-8507, Japan
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Raybould HE, Glatzle J, Freeman SL, Whited K, Darcel N, Liou A, Bohan D. Detection of macronutrients in the intestinal wall. Auton Neurosci 2006; 125:28-33. [PMID: 16504594 DOI: 10.1016/j.autneu.2006.01.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2006] [Revised: 01/07/2006] [Accepted: 01/07/2006] [Indexed: 01/09/2023]
Affiliation(s)
- Helen E Raybould
- Department of Anatomy, Physiology and Cell Biology, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA.
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Martín-Venegas R, Soriano-García JF, Vinardell MP, Geraert PA, Ferrer R. Oligomers Are Not the Limiting Factor in the Absorption of DL-2-Hydroxy-4-(methylthio)butanoic Acid in the Chicken Small Intestine. Poult Sci 2006; 85:56-63. [PMID: 16493946 DOI: 10.1093/ps/85.1.56] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The methionine hydroxy analogue DL-2-hydroxy-4-(methylthio)butanoic acid (HMB) is commonly used as a supplemental source of methionine in commercial animal diets. The HMB free acid is an aqueous solution that contains 88% product in an equilibrium mixture of monomer, dimer, and polymeric compounds. The present study examines whether the presence of these nonmonomeric forms reduces the absorption of the hydroxy analogue in the chicken small intestine. In vivo and in vitro methodologies were used to compare the intestinal absorption of an HMB product containing mainly monomer (HMB-PCM) with commercial HMB. The results from the in vivo perfusion of the jejunum showed no significant differences between the 2 hydroxy analogue sources in monomer absorption from the intestinal lumen, tissue accumulation, or plasma concentration. The results also indicate that the nonmonomeric forms are hydrolyzed during perfusion. Moreover, monomer tissue accumulation in everted sacs showed no significant differences between substrates, either in the presence or in the absence of a H+-gradient; a higher value was observed in the jejunum and ileum in comparison with the duodenum. Similarly, serosal appearance in H+-gradient conditions did not differ significantly between substrates, and it showed the same regional profile as in tissue accumulation. Oligomer hydrolysis was confirmed in vitro without significant differences between segments. In conclusion, the presence of nonmonomeric forms is not a limiting factor in HMB absorption, apparently because of the hydrolytic capacity of intestinal mucosa, as confirmed by experiments in vivo and in vitro.
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Affiliation(s)
- R Martín-Venegas
- Department de Fisiologia, Facultat de Farmàcia, Universitat de Barcelona
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Sai Y. Biochemical and molecular pharmacological aspects of transporters as determinants of drug disposition. Drug Metab Pharmacokinet 2005; 20:91-9. [PMID: 15855719 DOI: 10.2133/dmpk.20.91] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Membrane transporters are integral membrane proteins typically having 12 transmembrane domains. Most of the SLC family transporters consist of 300-800 amino acid residues with a molecular mass of 40-90 kDa, while the corresponding values of ABC family transporters are 1,200-1,500 residues and 140-180 kDa, respectively. Each transporter has a characteristic tissue distribution and subcellular localization. I have isolated cDNAs of various transporters, including oligopeptide transporter PEPT1, monocarboxylic acid transporter MCT1 and organic cation/carnitine transporters (OCTNs), and determined their tissue distribution and subcellular localization. I have also determined the absolute expression levels of transporters to evaluate their relative contributions to drug transport in various tissues. It is important to note that expression levels of transporters can be changed under various physiological conditions and by administration of drugs. Changes in expression level, subcellular localization and functional properties can all be involved in inter-individual differences in drug pharmacokinetics. Transporters are among the key determinants of drug disposition.
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Affiliation(s)
- Yoshimichi Sai
- Department of Pharmaceutics, Kyoritsu University of Pharmacy, 1-5-30 Sibakoen, Minato-ku, Tokyo 105-8512, Japan.
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Anderle P, Sengstag T, Mutch DM, Rumbo M, Praz V, Mansourian R, Delorenzi M, Williamson G, Roberts MA. Changes in the transcriptional profile of transporters in the intestine along the anterior-posterior and crypt-villus axes. BMC Genomics 2005; 6:69. [PMID: 15882471 PMCID: PMC1145182 DOI: 10.1186/1471-2164-6-69] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Accepted: 05/10/2005] [Indexed: 01/03/2023] Open
Abstract
Background The purpose of this work was to characterize the expression of drug and nutrient carriers along the anterior-posterior and crypt-villus axes of the intestinal epithelium and to study the validity of utilizing whole gut tissue rather than purified epithelial cells to examine regional variations in gene expression. Results We have characterized the mRNA expression profiles of 76 % of all currently known transporters along the anterior-posterior axis of the gut. This is the first study to describe the expression profiles of the majority of all known transporters in the intestine. The expression profiles of transporters, as defined according to the Gene Ontology consortium, were measured in whole tissue of the murine duodenum, jejunum, ileum and colon using high-density microarrays. For nine transporters (Abca1, Abcc1, Abcc3, Abcg8, Slc10a2, Slc28a2, Slc2a1, Slc34a2 and Slc5a8), the mRNA profiles were further measured by RT-PCR in laser micro-dissected crypt and villus epithelial cells corresponding to the aforementioned intestinal regions. With respect to differentially regulated transporters, the colon had a distinct expression profile from small intestinal segments. The majority (59 % for p cutoff ≤ 0.05) of transporter mRNA levels were constant across the intestinal sections studied. For the transporter subclass "carrier activity", which contains the majority of known carriers for biologically active compounds, a significant change (p ≤ 0.05) along the anterior-posterior axis was observed. Conclusion All nine transporters examined in laser-dissected material demonstrated good replication of the region-specific profiles revealed by microarray. Furthermore, we suggest that the distribution characteristics of Slc5a8 along the intestinal tract render it a suitable candidate carrier for monocarboxylate drugs in the posterior portion of the intestine. Our findings also predict that there is a significant difference in the absorption of carrier-mediated compounds in the different intestinal segments. The most pronounced differences can be expected between the adjoining segments ileum and colon, but the differences between the other adjoining segments are not negligible. Finally, for the examined genes, profiles measured in whole intestinal tissue extracts are representative of epithelial cell-only gene expression.
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Affiliation(s)
- Pascale Anderle
- ISREC, Swiss Institute for Experimental Cancer Research, 1066 Epalinges s/Lausanne, Switzerland
| | - Thierry Sengstag
- Swiss Institute for Experimental Cancer Research (ISREC) and Swiss Institute of Bioinformatics (SIB), NCCR Molecular Oncology, CH-1066 Epalinges s/Lausanne, Switzerland
| | - David M Mutch
- Nestle Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland
| | - Martin Rumbo
- ISREC, Swiss Institute for Experimental Cancer Research, 1066 Epalinges s/Lausanne, Switzerland
| | - Viviane Praz
- ISREC and Swiss Institute of Bioinformatics, 1066 Epalinges s/Lausanne, Switzerland
| | - Robert Mansourian
- Nestle Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland
| | - Mauro Delorenzi
- Swiss Institute for Experimental Cancer Research (ISREC) and Swiss Institute of Bioinformatics (SIB), NCCR Molecular Oncology, CH-1066 Epalinges s/Lausanne, Switzerland
| | - Gary Williamson
- Nestle Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland
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