Fructose, a prevalent hexose, has become a widely used food additive, with its usage rising significantly because of socio-economic advancements and shifts in human dietary habits. Excessive fructose intake has been implicated in obesity, cardiovascular disease, metabolic syndromes, inflammation, and cancer, among other disorders. This review discusses the absorption, distribution, and metabolism of fructose and the links between fructose metabolism and major metabolic pathways. The role of fructose in metabolic diseases, including metabolic dysfunction-associated fatty liver disease, hyperinsulinemia, and hyperuricemia, is also highlighted. Furthermore, the role of fructose in the development of chronic inflammation, including gut inflammation, liver inflammation, and neuroinflammation, is discussed. Lastly, in the context of cancer development, this review summarizes the dual role of fructose in tumors, both pro- and anti-tumor effects. Future studies on the role of fructose in cancer should focus on the complexity of physiological and pathological conditions, such as the specific tumor microenvironment and metabolic status. Fructose has been shown to induce metabolic reprogramming of multiple immune cells and increase pro-inflammatory immune responses; therefore, inhibiting or promoting its metabolism may regulate immune responses. And targeting fructose metabolism may be a promising approach to treating metabolic diseases, inflammation, and cancer.

High-fat diet causes elevation of steatosis, dyslipidemia and oxidative stress which eventually leads to hepatic injury in the form of non-alcoholic fatty liver disease (NAFLD). Naringin, a natural flavonoid, having tremendous potentiality including antioxidant, anti-inflammatory, hypolipidemic role. Based on this proposition, we investigated the role of naringin in hepatotoxicity and its possible underlying mechanism caused by high-fat diet for prolonged time. Fifteen Wistar rats were divided into three groups: Group A (CON) received normal diet; Group B (HFD) was administered with high-fat diet for 16 weeks; and Group C (THN) was treated with naringin (100 mg/kg B.W.) for last 6 weeks after induction of obesity. After autopsy, various parameters were studied like gravimetry, serum biochemistry, ROS activity, anti-oxidant enzymes, genes expression (AMPK and SREBP-1C), histochemistry, histopathology and ultrastructure of hepatic tissue. In HFD group, Masson's trichome stain intensity increased 6.8-folds, indicating the onset of liver fibrosis; ROS generation and lipid peroxidation (TBARS) were significantly (p < 0.01) increased, whereas SOD and CAT were decreased by 36.7 % and 49.7 %, respectively. Furthermore, these parameters were remained normal in THN group. Besides, HFD group displayed extreme elevation in hepatic SREBP-1C expression (147 %) and downregulation of AMPK gene (77 %) compared to control. The ultrastructural study revealed most important and new insight of this study where HFD induced extreme reticule stress in hepatic tissue which was significantly improved by the treatment of naringin. These findings demonstrate that the naringin may be used as a potential therapeutic agent to combat obesity related hyperlipidemia and NAFLD.

Nonalcoholic steatohepatitis (NASH) is a multifaceted liver disease. Endoplasmic reticulum stress (ERS), a key driver in NASH pathogenesis, triggers metabolic irregularities, liver steatosis, and inflammation. Genipin, an iridoid from the traditional Chinese medicine Gardenia jasminoides, has demonstrated significant effects against ERS. In the current work, 33 new genipin derivatives were designed and synthesized to evaluate their potential to treat NASH. Notably, G15 emerged as the most potent candidate, significantly attenuating lipid accumulation induced by free fatty acids (FFAs) in L-02 cells. Further investigation revealed that G15's mitigation of ERS was primarily achieved by suppressing the levels of inositol-requiring enzyme 1 (IRE1). Western blot analysis confirmed that G15 effectively down-regulated IRE1 protein expression and decreased the expression levels of its downstream X-box binding protein 1 (XBP1) and signal transducer and activator of transcription 3 (STAT3) proteins, thereby reducing cellular lipid accumulation. In addition, G15 treatment inhibited FFA-induced nitric oxide (NO) production in a concentration-dependent manner and suppressed the secretion of pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α. Collectively, these findings underscore that G15 has the potential to be a leading candidate for the treatment of NASH by down-regulating the IRE1/XBP1/STAT3 signaling pathway.

Resolvin D5 (RD5), a lipid mediator derived from DHA via 5-lipoxygenase signaling, has been shown to resolve inflammation in various disease models. This study aimed to investigate the role of RD5 in the development of hepatic steatosis in individuals with obesity and explore the detailed mechanisms involved. Protein expression was evaluated via Western blot analysis, whereas hepatic lipid deposition was examined via Oil Red O staining and triglyceride quantification. Autophagosomes were detected via MDC staining. Our findings indicated that RD5 treatment normalized lipogenic lipid accumulation, fatty acid uptake, oxidation, apoptosis, and endoplasmic reticulum (ER) stress in palmitate-treated primary hepatocytes. As a cytoprotective signaling pathway, RD5 treatment increased the expression of SIRT6 and autophagy markers, such as those involved in LC3 conversion and p62 degradation. The beneficial effects of RD5 on hepatic lipid metabolism, apoptosis, and ER stress were negated by SIRT6 small interfering RNA or 3-methyladenine, an inhibitor of autophagy. Furthermore, RD5 administration decreased hepatic steatosis, apoptosis, and ER stress in the livers of high-fat diet (HFD)-fed mice. In line with the in vitro results, RD5 treatment elevated SIRT6 and autophagy levels in the livers of HFD-fed mice. These novel findings suggest that RD5 improves hepatic lipid metabolism, apoptosis and ER stress through SIRT6/autophagy signaling, thereby attenuating hepatic steatosis. RD5 may have therapeutic potential for treating nonalcoholic fatty liver disease with minimal side effects.

Background/Objectives: Endoplasmic reticulum stress (ERS) contributes to hepatocyte inflammation, triggered by prolonged exposure to lipotoxicity, and promotes non-alcoholic fatty liver disease (NAFLD) progression by recruiting and activating hepatic macrophages, which accelerate fibrosis and exacerbate disease progression. Here, we aimed to evaluate the therapeutic potential of ginsenoside Rh2 (Rh2) in a cell model of NAFLD induced by the ERS inducer thapsigargin (THA). Methods: HepG2 cells were treated with THA to induce ERS and mimic NAFLD conditions. The effects of Rh2 on ERS, lipid accumulation, and apoptosis were assessed in HepG2 cells. Additionally, THP-1 cells were used to investigate macrophage activation upon exposure to conditioned medium (CM) from THA- and Rh2-treated HepG2 cells. Gene and protein expression of inflammatory and lipid synthesis markers were analyzed, as well as M1/M2 macrophage polarization markers. Results: Rh2 inhibited THA-induced apoptosis, ERS, and lipid accumulation in HepG2 cells. It also reduced the expression of lipid synthesis genes (SREBF1, FAS) and inflammatory markers (IL-6, IL-1β, TNF-α, MCP-1). CM from Rh2-treated HepG2 cells suppressed macrophage activation in THP-1 cells, decreased M1 polarization markers (CD80, CD86), and increased M2 markers (CD163, Arg1, MRC-1). Conclusions: These results suggest that Rh2 effectively suppresses inflammation and lipid storage in ERS-induced HepG2 cells while modulating the crosstalk between hepatocytes and macrophages. These findings underscore the potential of Rh2 as a promising therapeutic agent for the prevention and early intervention of NAFLD progression.

Metabolic associated steatohepatitis characterized by lipid accumulation, inflammation and fibrosis, is a growing global health issue, contributing to severe liver-related mortality. With limited effective treatments available, there is an urgent need for novel therapeutic strategies. Moringa oleifera, rich in antioxidants, offers potential for combating steatohepatitis, but its cytotoxicity presents challenges. Aloe vera, renowned for its cytocompatibility and anti-inflammatory effects, shows promise in mitigating these risks. Using infrared spectrometry and mass spectrometry, we identified 1586 metabolites from both plants across 84 chemical classes. By encapsulating these phytochemicals in nanoparticles, we achieved increased solubility, cytocompatibility, and gene modulation to hepatic stellate cells affected by steatohepatitis. Chemoinformatic analysis revealed bioactive metabolites, including hesperetin analogs, known to inhibit TGF-β. Our results demonstrate that these nanoparticles not only improved gene expression modulation related to metabolic associated steatohepatitis, particularly TGF-β and COL1A1, but also outperformed free compounds, highlighting their potential as a novel therapeutic approach.

Donepezil (Do), a drug known for its ability to reduce neuronal inflammation and for its use in the treatment of Alzheimer's disease, has shown promise in combating hepatic lipid accumulation in hyperlipidemic conditions and endoplasmic reticulum (ER) stress, a factor associated with alterations in hepatic lipid metabolism. However, the mechanisms by which these problems are alleviated have not been fully elucidated. In this study, we investigated the effects of Do on hepatic lipid metabolism through both in vitro and in vivo studies. We examined the expression of proteins associated with lipogenesis and ER stress via immunoblot analysis, and hepatic lipid accumulation was assessed via oil red O staining. In addition, autophagosome formation was analyzed by counting MDC-positive cells. Our results demonstrated that Do treatment improved hepatic lipid metabolism and reduced the expression of ER stress markers, resulting in decreased lipogenic lipid deposition and apoptosis in the hepatocytes and livers of hyperlipidemic mice. Mechanistically, knocking down AMPK or inhibiting autophagy with 3-methyladenine (3 MA) attenuated the effects of Do on palmitate-exposed hepatocytes. These results suggest that Do alleviates hepatic ER stress via the AMPK/autophagy pathway and AMPK-mediated fatty acid oxidation, resulting in improved hepatic lipid metabolism and reduced hepatic steatosis and apoptosis. Our study provides evidence that Do may be a promising therapeutic approach for Alzheimer's disease patients with metabolic dysfunction-associated steatotic liver disease (MASLD).

Background/Objectives: Trefoil factor protein 3 (Tff3) is a small peptide known as an epithelial tissue-protective protein, and it is also identified as a novel participant in complex metabolic processes. In numerous mouse models of obesity, Tff3 has been found to be downregulated in the liver and its overexpression is associated with an improvement in metabolic parameters. These mouse models with metabolic phenotypes have a multigenic background, with numerous genes contributing to their phenotype. To elucidate the role of Tff3 protein in metabolic events, we developed a mouse model with Tff3 deficiency on a C57Bl6N background without other intrinsic mutations affecting metabolism. Methods: We investigated the effects of a high-fat diet (9 weeks) on the liver of Tff3 protein-deficient mice of both sexes and the corresponding wild type. We investigated the general metabolic status of the animals and analysed the expression of markers of relevant pathophysiological pathways in the liver. Results:Tff3-deficient mice had significantly lower body weight. They also had a comparable total liver fat content but it was distributed in small vesicles, indicating the protective effect of Tff3 deficiency. The results of molecular analysis showed no major gene expression changes in inflammation-, ER- and oxidative stress-, and lipid metabolism-related genes. Tff3-/- males had reduced expression of Il1α and Cxcr7 genes in the liver and no global proteome changes; Tff3-deficient females had decreased expression of Irs2 and Atf4 genes and total proteome comparison showed decreased levels of proteins related to ribosome biosynthesis and the inhibition of acetylation. Conclusions: Our results demonstrate that Tff3 deficiency reduces lipid accumulation in the liver and we set the direction for further studies aimed at uncovering the exact molecular mechanisms in other organs. Furthermore, it emphasises the need to include both sexes in future research, as the observed phenotype differs significantly depending on sex.

Metabolic dysfunction-associated steatohepatitis (MASH), a progressive form of fatty liver disease, presents a significant global health challenge. Despite extensive research, fully elucidating its complex pathogenesis and developing accurate non-invasive diagnostic tools remain key goals. Multi-omics approaches, integrating data from transcriptomics, proteomics, metabolomics, and lipidomics, offer a powerful strategy to achieve these aims. This review summarizes key findings from multi-omics studies in MASH, highlighting their contributions to our understanding of disease mechanisms and the development of improved diagnostic models. Transcriptomic studies have revealed widespread gene dysregulation affecting lipid metabolism, inflammation, and fibrosis, while proteomics has identified altered protein expression patterns and potential biomarkers. Metabolomic and lipidomic analyses have further uncovered significant changes in various metabolites and lipid species, including ceramides, sphingomyelins, phospholipids, and bile acids, underscoring the central role of lipid dysregulation in MASH. These multi-omics findings have been leveraged to develop novel diagnostic models, some incorporating machine learning algorithms, with improved accuracy compared to traditional methods. Further research is needed to validate these findings, explore the complex interplay between different omics layers, and translate these discoveries into clinically useful tools for improved MASH diagnosis and prognosis.

In recent years, there have been significant advances in pathological research on alcoholic liver disease (ALD), with suitable animal models making a significant contribution. However, the currently established animal ALD models still have some significant drawbacks, especially the inability to induce the entire human ALD lineage, which may be related to physiological differences between animals and humans. This review comprehensively summarized the most widely used experimental models of ALD, including voluntary drinking, Lieber-DeCarli, Meadows-Cook, Tsukamoto-French, NIAAA, and the "second hit" model. "Second hit" refers to an additional factor that damages the liver. There are various "second hit" models that fall into two main categories: particular diets and drugs. These models can either simulate human drinking patterns more accurately or produce varying degrees of ALD without significantly increasing animal mortality. We introduced the established method of the original models, discussed the advantages and disadvantages of the existing models from the aspects of operability and practicality, and provided existing improvement methods, hoping to provide a reference for future researchers.

Hepatic endoplasmic reticulum (ER) stress is implicated in the development of steatosis and its progression to nonalcoholic steatohepatitis (NASH). The ER in the liver can sustain metabolic function by activating defense mechanisms that delay or prevent the progression of nonalcoholic fatty liver disease (NAFLD). However, the precise mechanisms by which the ER stress response protects against NAFLD remain largely unknown. Recently, activin E has been linked to metabolic diseases such as insulin resistance and NAFLD. However, the physiological conditions and regulatory mechanisms driving hepatic Inhbe expression (which encodes activin E) as well as the metabolic role of activin E in NAFLD require further investigation. Here we found that hepatic Inhbe expression increased under prolonged fasting and ER stress conditions, which was mediated by ATF4, as determined by promoter analysis in a mouse model. Consistently, a positive correlation between INHBE and ATF4 expression levels in relation to NAFLD status was confirmed using public human NAFLD datasets. To investigate the role of activin E in hepatic steatosis, we assessed the fluxes of the lipid metabolism in an Inhbe-knockout mouse model. These mice displayed a lean phenotype but developed severe hepatic steatosis under a high-fat diet. The deficiency of Inhbe resulted in increased lipolysis in adipose tissue, leading to increased fatty acid influx into the liver. Conversely, hepatic overexpression of Inhbe ameliorated hepatic steatosis by suppressing lipolysis in adipose tissue through ALK7-Smad signaling. In conclusion, activin E serves as a regulatory hepatokine that prevents fatty acid influx into the liver, thereby protecting against NAFLD.

Type 2 diabetes mellitus (T2DM) is an intricate disease correlated with many metabolic deregulations, including disordered glucose metabolism, oxidative stress, inflammation, and cellular apoptosis due to hepatic gluconeogenesis aberrations. However, there is no radical therapy to inhibit hepatic gluconeogenesis disturbances yet. We thus sought to probe the effectiveness and uncover the potential mechanism of quercetin (QCT) and silk sericin (SS) in mitigating hyperglycemia-induced hepatic gluconeogenesis disorder, which remains obscure. Administration of QCT and SS to diabetic male albino rats markedly restored the levels of glucose, insulin, advanced glycation end-products (AGEs), liver function enzymes, alpha-fetoprotein (AFP), globulin, and glycogen, in addition to hepatic carbohydrate metabolizing enzymes and gluconeogenesis in comparison with diabetic rats. Furthermore, treatment with QCT and SS modulated hepatic malondialdehyde (MD), reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), nitric oxide, tumor necrosis factor-alpha (TNF-α), and interleukin-1β (IL-1β), in addition to serum interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2), implying their effectiveness in safeguarding cells against oxidative impairment and inflammation. Remarkably, QCT and SS treatments led to the upregulation of expression of phosphatidylinositol 3-kinases (PI3K), phospho-Akt (p-Akt), and forkhead box-O1 (FOXO1) genes in hepatic tissues compared to diabetic rats, orchestrating these singling pathways for curtailing hyperglycemia and pernicious consequences in hepatic tissues. Importantly, immunohistochemical investigations exhibited downregulation of caspase-3 expression in rats treated with QCT and SS compared to diabetic animals. Beyond that, the histopathological results of hepatic tissues demonstrated notable correlations with biochemical findings. Interestingly, the in silico results supported the in vivo findings, showing notable binding affinities of QCT and SS to PI3K, GPx, and TNF-α proteins. These results imply that QCT and SS could mitigate oxidative stress and inflammation and regulate hepatic gluconeogenesis in diabetic rats. However, QCT revealed greater molecular interactions with the studied proteins than SS. Overall, our results emphasize that QCT and SS have significant therapeutic effects on attenuating hyperglycemia-induced hepatic gluconeogenesis, with QCT showing superior effectiveness.

Nucleotide-binding Oligomerization Domain 1 (NOD1) is a cytosolic pattern recognition receptor that senses specific bacterial peptidoglycan moieties, leading to the induction of inflammatory response. Besides, sensing peptidoglycan, NOD1 has been reported to sense metabolic disturbances including the ER stress-induced unfolded protein response (UPR). However, the underpinning crosstalk between the NOD1 activating microbial ligands and the metabolic cues to alter metabolic response is not yet comprehensively defined. Here, we show that underlying ER stress aggravated peptidoglycan-induced NOD1-mediated inflammatory response in hepatoma cells. The HepG2 cells, undergoing ER stress induced by thapsigargin exhibited an amplified inflammatory response induced by peptidoglycan ligand of NOD1 (i.e. iE-DAP). This aggravated inflammatory response disrupted lipid and glucose metabolism, characterized by de novo lipogenic response, and increased gluconeogenesis in HepG2 cells. Further, we characterized that the aggravation of NOD1-induced inflammatory response was dependent on inositol-requiring enzyme 1-α (IRE1-α) and protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) activation, in conjunction with calcium flux. Altogether, our findings suggest that differential UPR activation makes liver cells more sensitive towards bacterial-derived ligands to pronounce inflammatory response in a NOD1-dependent manner that impairs hepatic nutrient metabolism.

Upadacitinib (UPA) has been utilized to treat conditions such as rheumatoid arthritis, psoriatic arthritis, atopic dermatitis, ulcerative colitis, Crohn's disease, ankylosing spondylitis, and axial spondyloarthritis by modulating inflammation via the JAK pathway. However, its impact on hepatic lipogenesis remains insufficiently studied. This research evaluated protein expression through Western blotting, lipid accumulation with oil red O staining, autophagosomes in hepatocytes via MDC staining, and hepatic apoptosis via cell viability and caspase 3 activity assays. This study aimed to explore the effects of UPA on hepatic lipogenesis and the underlying molecular mechanisms in in vitro models of hepatic steatosis. These findings demonstrated that UPA reduced lipid deposition, apoptosis, and ER stress in palmitate-treated hepatocytes. UPA treatment inhibited phosphorylated JAK1 and STAT3 while promoting the expression of phosphorylated AMPK and autophagy markers. AMPK siRNA negated the effects of UPA on lipogenic lipid deposition, apoptosis, JAK1/STAT3 phosphorylation, and ER stress. These results reveal that UPAmitigates ER stress through the JAK1/STAT3/AMPK pathway, thereby reducing lipid deposition and apoptosis in hyperlipidemic hepatocytes, supporting its potential as a therapeutic strategy for treating hepatic steatosis in obese individuals.

Uvaol (UV), a pentacyclic triterpene found in olives and virgin olive oil, is known for its anti-inflammatory and antioxidant effects in various disease models. While olive oil is reported to reduce obesity and insulin resistance, the specific impact of UV on liver lipid metabolism and its molecular mechanisms are not fully understood. In this study, hepatic lipid accumulation was measured using oil red O staining, and protein expression levels in liver cells were assessed via Western blot analysis. Apoptosis was evaluated through cell viability and caspase 3 activity assays. UV treatment reduced lipid accumulation, fatty acid uptake, apoptosis, and ER stress in palmitate-treated liver cells. Additionally, UV enhanced fatty acid oxidation. Mechanistically, increased SIRT6 expression and autophagy were observed in UV-treated cells. SIRT6-targeted siRNA or 3-methyladenine blocked the effects of UV in hyperlipidemic cells. In conclusion, UV improves SIRT6/autophagy signaling, reducing lipid deposition and apoptosis in liver cells under high lipid conditions. This in vitro study provides strong evidence for potential therapeutic strategies for hepatic steatosis.

Nonalcoholic steatohepatitis (NASH) represents a severe disease subtype of nonalcoholic fatty liver disease (NAFLD) that is thought to be highly associated with systemic metabolic abnormalities. It is characterized by a series of substantial liver damage, including hepatocellular steatosis, inflammation, and fibrosis. The end stage of NASH, in some cases, may result in cirrhosis and hepatocellular carcinoma (HCC). Nowadays a large number of investigations are actively under way to test various therapeutic strategies, including emerging oligonucleotide drugs (e.g., antisense oligonucleotide, small interfering RNA, microRNA, mimic/inhibitor RNA, and small activating RNA) that have shown high potential in treating this fatal liver disease. This article systematically reviews the pathogenesis of NASH/NAFLD, the promising druggable targets proven by current studies in chemical compounds or biological drug development, and the feasibility and limitations of oligonucleotide-based therapeutic approaches under clinical or pre-clinical studies.

Interleukin-27 (IL-27) is a recently discovered cytokine that has been implicated in inflammatory and metabolic conditions, such as atherosclerosis and insulin resistance. However, the mechanisms by which IL-27 attenuates hepatic lipid accumulation in hyperlipidemic conditions and counteracts endoplasmic reticulum (ER) stress, a known risk factor for impaired hepatic lipid metabolism, have not been elucidated. This in vitro study was designed to examine the effect of IL-27 on hepatic lipid metabolism. The study included the evaluation of lipogenesis-associated proteins and ER stress markers by Western blotting, the determination of hepatic lipid accumulation by Oil Red O staining, and the examination of autophagosome formation by MDC staining. The results showed that IL-27 treatment reduced lipogenic lipid deposition and the expression of ER stress markers in cultured hepatocytes exposed to palmitate. Moreover, treatment with IL-27 suppressed CD36 expression and enhanced fatty acid oxidation in palmitate-treated hepatocytes. The effects of IL-27 on hyperlipidemic hepatocytes were attenuated when adenosine monophosphate-activated protein kinase (AMPK) or 3-methyladenine (3 MA) were inhibited by small interfering RNA (siRNA). These results suggest that IL-27 attenuates hepatic ER stress and fatty acid uptake and stimulates fatty acid oxidation via AMPK/autophagy signaling, thereby alleviating hepatic steatosis. In conclusion, this study identified IL-27 as a promising therapeutic target for nonalcoholic fatty liver disease (NAFLD).

NASH, characterized by inflammation and fibrosis, is emerging as a leading etiology of HCC. Lipidomics analyses in the liver have shown that the levels of polyunsaturated phosphatidylcholine (PC) are decreased in patients with NASH, but the roles of membrane PC composition in the pathogenesis of NASH have not been investigated. Lysophosphatidylcholine acyltransferase 3 (LPCAT3), a phospholipid (PL) remodeling enzyme that produces polyunsaturated PLs, is a major determinant of membrane PC content in the liver.

The expression of LPCAT3 and the correlation between its expression and NASH severity were analyzed in human patient samples. We examined the effect of Lpcat3 deficiency on NASH progression using Lpcat3 liver-specific knockout (LKO) mice. RNA sequencing, lipidomics, and metabolomics were performed in liver samples. Primary hepatocytes and hepatic cell lines were used for in vitro analyses. We showed that LPCAT3 was dramatically suppressed in human NASH livers, and its expression was inversely correlated with NAFLD activity score and fibrosis stage. Loss of Lpcat3 in mouse liver promotes both spontaneous and diet-induced NASH/HCC. Mechanistically, Lpcat3 deficiency enhances reactive oxygen species production due to impaired mitochondrial homeostasis. Loss of Lpcat3 increases inner mitochondrial membrane PL saturation and elevates stress-induced autophagy, resulting in reduced mitochondrial content and increased fragmentation. Furthermore, overexpression of Lpcat3 in the liver ameliorates inflammation and fibrosis of NASH.

These results demonstrate that membrane PL composition modulates the progression of NASH and that manipulating LPCAT3 expression could be an effective therapeutic for NASH.

Interleukin-38 (IL-38), recently recognized as a cytokine with anti-inflammatory properties that mitigate type 2 diabetes, has been associated with indicators of insulin resistance and nonalcoholic fatty liver disease (NAFLD). This study investigated the impact of IL-38 on hepatic lipid metabolism and endoplasmic reticulum (ER) stress. We assessed protein expression levels using Western blot analysis, while monodansylcadaverine staining was employed to detect autophagosomes in hepatocytes. Oil red O staining was utilized to examine lipid deposition. The study revealed elevated serum IL-38 levels in high-fat diet (HFD)-fed mice and IL-38 secretion from mouse keratinocytes. IL-38 treatment attenuated lipogenic lipid accumulation and ER stress markers in hepatocytes exposed to palmitate. Furthermore, IL-38 treatment increased AMP-activated protein kinase (AMPK) phosphorylation and autophagy. The effects of IL-38 on lipogenic lipid deposition and ER stress were nullified in cultured hepatocytes by suppressing AMPK through small interfering (si) RNA or 3-methyladenine (3MA). In animal studies, IL-38 administration mitigated hepatic steatosis by suppressing the expression of lipogenic proteins and ER stress markers while reversing AMPK phosphorylation and autophagy markers in the livers of HFD-fed mice. Additionally, AMPK siRNA, but not 3MA, mitigated IL-38-enhanced fatty acid oxidation in hepatocytes. In summary, IL-38 alleviates hepatic steatosis through AMPK/autophagy signaling-dependent attenuation of ER stress and enhancement of fatty acid oxidation via the AMPK pathway, suggesting a therapeutic strategy for treating NAFLD.

Endoplasmic Reticulum Stress (ERS) is a key factor in the development of Non-Alcoholic Fatty Liver Disease (NAFLD) in diabetes. The current study aimed to examine the effects of exercise and IGF-I on ERS markers in liver tissue. Rats were divided into five groups (n = 8 per group), including control (CON), diabetes (DIA), diabetes + exercise (DIA + EX), diabetes + IGF-I (DIA + IGF-I), and diabetes + exercise + IGF-I (DIA + EX + IGF-I). Type 1 diabetes was induced by an I.P. injection of streptozotocin (60 mg/kg). After 30 days of treatment with exercise or IGF-I alone or in combination, liver tissue was assessed for caspase 12, 8, and CHOP protein levels, and expression of ERS markers (ATF-6, PERK, IRE-1A) and lipid metabolism-involved genes (FAS, FXR, SREBP-1c) by western immunoblotting. In addition, for the evaluation of histopathological changes in the liver, Hematoxylin - Eosin and Masson's Trichrome staining were done. Compared to the control group, diabetes significantly caused liver fibrosis, induced ERS, increased caspase 12 and 8 levels in the liver, and changed expression levels of genes associated with lipid metabolism, including FAS, FXR, and SREBP-1c. Treatment with either exercise or IGF-I reduced fibrosis levels suppressed ER stress markers and apoptosis, and improved expression of genes associated with lipid metabolism. In addition, simultaneous treatment with exercise and IGF-I showed a synergistic effect compared to DIA + E and DIA + IGF-I. The results suggest that IGF-1 and exercise reduced liver fibrosis possibly by reducing ERS, creating adaptive ER stress status, and improving protein folding.

Adipose tissue (AT), once considered a mere fat storage organ, is now recognized as a dynamic and complex entity crucial for regulating human physiology, including metabolic processes, energy balance, and immune responses. It comprises mainly two types: white adipose tissue (WAT) for energy storage and brown adipose tissue (BAT) for thermogenesis, with beige adipocytes demonstrating the plasticity of these cells. WAT, beyond lipid storage, is involved in various metabolic activities, notably lipogenesis and lipolysis, critical for maintaining energy homeostasis. It also functions as an endocrine organ, secreting adipokines that influence metabolic, inflammatory, and immune processes. However, dysfunction in WAT, especially related to obesity, leads to metabolic disturbances, including the inability to properly store excess lipids, resulting in ectopic fat deposition in organs like the liver, contributing to non-alcoholic fatty liver disease (NAFLD). This narrative review delves into the multifaceted roles of WAT, its composition, metabolic functions, and the pathophysiology of WAT dysfunction. It also explores diagnostic approaches for adipose-related disorders, emphasizing the importance of accurately assessing AT distribution and understanding the complex relationships between fat compartments and metabolic health. Furthermore, it discusses various therapeutic strategies, including innovative therapeutics like adipose-derived mesenchymal stem cells (ADMSCs)-based treatments and gene therapy, highlighting the potential of precision medicine in targeting obesity and its associated complications.

Non-alcoholic fatty liver disease (NAFLD) is a liver disorder characterized by the ac-cumulation of fat in hepatocytes without alcohol consumption. Mitochondrial dysfunction and endoplasmic reticulum (ER) stress play significant roles in NAFLD pathogenesis. The unfolded protein response in mitochondria (UPRmt) is an adaptive mechanism that aims to restore mitochondrial protein homeostasis and mitigate cellular stress. This study aimed to investigate the effects of ( +)-Lipoic acid (ALA) on UPRmt, inflammation, and oxidative stress in an in vitro model of NAFLD using HepG2 cells treated with palmitic acid and oleic acid to induce steatosis.

Treatment with palmitic and oleic acids increased UPRmt-related proteins HSP90 and HSP60 (heat shock protein), and decreased CLPP (caseinolytic protease P), indicating ER stress activation. ALA treatment at 1 μM and 5 μM restored UPRmt-related protein levels. PA:OA (palmitic acid:oleic acid)-induced ER stress markers IRE1α (Inositol requiring enzyme-1), CHOP (C/EBP Homologous Protein), BIP (Binding Immunoglobulin Protein), and BAX (Bcl-2-associated X protein) were significantly reduced by ALA treatment. ALA also enhanced ER-mediated protein glycosylation and reduced oxidative stress, as evidenced by decreased GPX1 (Glutathione peroxidase 1), GSTP1 (glutathione S-transferase pi 1), and GSR (glutathione-disulfide reductase) expression and increased GSH (Glutathione) levels, and improved cellular senescence as shown by the markers β-galactosidase, γH2Ax and Klotho-beta.

In conclusion, ALA ameliorated ER stress, oxidative stress, and inflammation in HepG2 cells treated with palmitic and oleic acids, potentially offering therapeutic benefits for NAFLD providing a possible biochemical mechanism underlying ALA beneficial effects.

Endoplasmic reticulum (ER) stress, promoting lipid metabolism disorders and steatohepatitis, contributes significantly to the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Hugan Qingzhi tablets (HQT) has a definite effect in the clinical treatment of NAFLD patients, but its mechanism is still unclear. This study aims to investigate the effects of HQT on ER stress in the liver tissues of NAFLD rats and explore the underlying mechanism.

The NAFLD rat model was managed with high-fat diet (HFD) for 12weeks. HQT was administrated in a daily basis to the HFD groups. Biochemical markers, pro-inflammatory cytokines, liver histology were assayed to evaluate HQT effects in HFD-induced NAFLD rats. Furthermore, the expression of ER stress-related signal molecules including glucose regulating protein 78 (GRP78), protein kinase RNA-like endoplasmic reticulum kinase (PERK), p-PERK, eukaryotic translation initiation factor 2α (EIF2α), p-EIF2α, activating transcription factor 4 (ATF4), acetyl-coenzyme A-carboxylase (ACC), activating transcription factor (ATF6), and nuclear factor-kappa B-p65 (NF-κB-p65) were detected by western blot and/or qRT-PCR.

The histopathological characteristics and biochemical data indicated that HQT exhibited protective effects on HFD-induced NAFLD rats. Furthermore, it caused significant reduction in the expression of ERS markers, such as GRP78, PERK, p-PERK, and ATF6, and subsequently downregulated the expression of EIF2α, p-EIF2α ATF4, ACC, and NF-κB-p65.

The results suggested that HQT has protective effect against hepatic steatosis and inflammation in NAFLD rats by attenuating ER stress, and the potential mechanism is through inhibition of PERK and ATF6 pathways.

Nonalcoholic fatty liver disease (NAFLD), characterized by excess liver triglyceride accumulation (hepatic steatosis), leads to an increased risk for cardiometabolic diseases and obesity-related mortality. Emerging evidence points to endoplasmic reticulum (ER) stress in the central nervous system as critical in NAFLD pathogenesis. Here, we tested the contribution of ER stress in a circumventricular organ-hypothalamic circuit in NAFLD development during obesity.

C57BL/6J male mice were fed a high-fat diet (HFD) or normal chow. A combination of histological, viral tracing, intersectional viral targeting, and in vivo integrative physiological approaches were used to examine the role of ER stress in subfornical organ to hypothalamic paraventricular nucleus projecting neurons (SFO➔PVN) in NAFLD during diet-induced obesity.

Immunohistochemical analysis revealed marked unfolded protein response activation in the SFO, particularly in excitatory SFO➔PVN neurons of HFD-fed animals. Moreover, intersectional viral inhibition of ER stress in SFO➔PVN neurons resulted in a reduction in hepatomegaly, hepatic steatosis, and a blunted increase in body weight gain during diet-induced obesity, independent of changes in food intake, substrate partitioning, energy expenditure, and ambulatory activity.

These results indicate that ER stress in an SFO➔PVN neural circuit contributes to hepatic steatosis during obesity.

Endoplasmic reticulum (ER) stress plays a pivotal role in adipogenesis, which encompasses the differentiation of adipocytes and lipid accumulation. Sustained ER stress has the potential to disrupt the signaling of the unfolded protein response (UPR), thereby influencing adipogenesis. This comprehensive review illuminates the molecular mechanisms that underpin the interplay between ER stress and adipogenesis. We delve into the dysregulation of UPR pathways, namely, IRE1-XBP1, PERK and ATF6 in relation to adipocyte differentiation, lipid metabolism, and tissue inflammation. Moreover, we scrutinize how ER stress impacts key adipogenic transcription factors such as proliferator-activated receptor γ (PPARγ) and CCAAT-enhancer-binding proteins (C/EBPs) along with their interaction with other signaling pathways. The cellular ramifications include alterations in lipid metabolism, dysregulation of adipokines, and aged adipose tissue inflammation. We also discuss the potential roles the molecular chaperones cyclophilin A and cyclophilin B play in adipogenesis. By shedding light on the intricate relationship between ER stress and adipogenesis, this review paves the way for devising innovative therapeutic interventions.

The steatotic diseases of metabolic dysfunction-associated steatotic liver disease (MASLD), alcohol-associated liver disease (ALD), and chronic hepatitis C (HCV) account for the majority of liver disease prevalence, morbidity, and mortality worldwide. While these diseases have distinct pathogenic and clinical features, dysregulated lipid droplet (LD) organelle biology represents a convergence of pathogenesis in all three. With increasing understanding of hepatocyte LD biology, we now understand the roles of LD proteins involved in these diseases but also how genetics modulate LD biology to either exacerbate or protect against the phenotypes associated with steatotic liver diseases. Here, we review the history of the LD organelle and its biogenesis and catabolism. We also review how this organelle is critical not only for the steatotic phenotype of liver diseases but also for their advanced phenotypes. Finally, we summarize the latest attempts and challenges of leveraging LD biology for therapeutic gain in steatotic diseases. In conclusion, the study of dysregulated LD biology may lead to novel therapeutics for the prevention of disease progression in the highly prevalent steatotic liver diseases of MASLD, ALD, and HCV.

Non-alcoholic fatty liver (NAFL) is a prevalent hepatic disorder of global significance that can give rise to severe complications. This research endeavor delves into the potential of nano-liposomal formulated Lycopene (Lip-Lyco) in averting the development of obesity and insulin resistance, both of which are major underlying factors contributing to NAFL. The investigation further scrutinizes the impact of Lip-Lyco on intricate cellular pathways within the liver tissue of rats induced with NAFL, specifically focusing on the progression of steatosis and fibrosis. To establish an obesity-NAFL model, twenty rats were subjected to a high-fat diet (HFD) for a duration of twelve weeks, after which they received an oral treatment of Lip-Lyco (10mg/kg) for an additional eight weeks. Another group of sixteen non-obese rats were subjected to treatment with or without Lip-Lyco, serving as a control for comparison. Results: The rats on a hypercaloric diet had high body mass index (BMI) and insulin resistance, reflected in disturbed serum adipokines and lipid profiles. Oxidative stress, inflammation, and apoptosis were evident in hepatic tissue, and the autophagic process in hepatocytes was inhibited. Additionally, the hedgehog pathway was activated in the liver tissue of NAFL group. Lip-Lyco was found to counteract all these aspects of NAFL pathogenesis. Lip-Lyco exhibited antioxidant, anti-inflammatory, hypoglycemic, antiapoptotic, autophagy-inducing, and Hedgehog signaling inhibitory effects. This study concludes that Lip-Lyco, a natural compound, has promising therapeutic potential in combating NAFLdisease. However, more experimental and clinical studies are required to confirm the effectiveness of lycopene in treating NAFLdisease.

To explore the specific protective mechanism of 3021 meal replacement powder (MRP) against non-alcoholic fatty liver disease (NAFLD).

C57BL/6J male mice were divided into four groups: control group, 3021 MRP group, model group and test group. The lipid accumulation and endoplasmic reticulum stress (ERS)-related proteins in hepatocytes of mice were detected by hematoxylin-eosin (HE) staining, oil red O staining and Western blotting.

The expressions of GRP78, GRP94, p-PERK and p-IRE1α were significantly inhibited in test group compared with those in model group. The protein expressions of p-NF-κB, p-JNK, IL-1β, IL-18 and NOX4 in test group were also significantly lower than those in model group. In vivo and in vitro experiments revealed that the body weight and lipid droplet content, and the expressions of ERS-related proteins (including BIP and XBP-1) in liver tissues all significantly declined in model group compared with those in 3021 MRP group.

In conclusion, 3021 MRP can greatly reduce lipid accumulation by inhibiting ERS, oxidative stress and inflammatory response in NAFLD.

The simultaneous exposure to a high-fat (HF) diet and to bisphenol A (BPA) from delivered foods and food-delivery containers is on the rise in humans, according to the increased frequency of food delivery during the COVID-19 pandemic. This co-exposure could cause harmful tissue toxicity in the human body. Here, the preventive effect of Allium macrostemon Bunge (AM) extract against dysfunction in adipose tissue and the liver under co-exposure to BPA and an HF diet was examined using mice. C57BL/6N mice were divided into four groups (n = 6 or 7/group) according to diet and treatment: control diet with vehicle (CON), HF diet with vehicle (HF), HF diet with an oral injection of BPA (HF + BP), and HF diet with an oral injection of BPA and AM extract (HF + BP + AM). HF feeding increased body weight gain compared to CON feeding, while BP + HF and BP + HF + AM feeding suppressed body weight gain compared with HF feeding. The BP + HF group had lower body weight than the HF group, but the two groups had similar epididymal fat mass. The HF + BP + AM group showed lower pro-inflammatory gene expression levels in adipose tissue and epididymal fat mass compared to the HF + BP group. Altered endoplasmic reticulum (ER) stress response in the liver was partly observed in the HF + BP group, as shown by increased total phosphorylated Jun N-terminal kinase protein levels compared to those in the HF group. In addition, ecdysterone 25-O-β-D-glucopyranoside and 6-gingerol were identified in AM extract by mass spectrometry and molecular networking analysis. In summary, the AM extract diminished adipose tissue inflammation and hepatic ER stress in an HF diet and BPA co-exposure condition. To utilize AM as a potential food component to alleviate the harmful effect of an HF diet and BPA exposure, further research investigating the specific impact of AM extract supplementation using additional experimental groups or various treatment doses is warranted.

Endonuclease G (ENDOG), a nuclear-encoded mitochondrial intermembrane space protein, is well known to be translocated into the nucleus during apoptosis. Recent studies have shown that ENDOG might enter the mitochondrial matrix to regulate mitochondrial genome cleavage and replication. However, little is known about the role of ENDOG in the cytosol. Our previous work showed that cytoplasmic ENDOG competitively binds with 14-3-3γ, which released TSC2 to repress mTORC1 signaling and induce autophagy. Here, we demonstrate that cytoplasmic ENDOG could also release Rictor from 14-3-3γ to activate the mTORC2-AKT-ACLY axis, resulting in acetyl-CoA production. Importantly, we observe that ENDOG could translocate to the ER, bind with Bip, and release IRE1a/PERK to activate the endoplasmic reticulum stress response, promoting lipid synthesis. Taken together, we demonstrate that loss of ENDOG suppresses acetyl-CoA production and lipid synthesis, along with reducing endoplasmic reticulum stress, which eventually alleviates high-fat diet-induced nonalcoholic fatty liver disease in female mice.

Oxidative stress triggers metabolic-associated fatty liver disease (MAFLD) and fibrosis. Previous animal studies demonstrated that the transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF2), the master regulator of antioxidant response, protects against MAFLD and fibrosis. S217879, a next generation NRF2 activator has been recently shown to trigger diet-induced steatohepatitis resolution and to reduce established fibrosis in rodents. Our aim was to evaluate the therapeutic potential of S217879 in human MAFLD and its underlying mechanisms using the relevant experimental 3D model of patient-derived precision cut liver slices (PCLS).

We treated PCLS from 12 patients with varying stages of MAFLD with S217879 or elafibranor (peroxisome proliferator-activated receptor [PPAR]α/δ agonist used as a referent molecule) for 2 days. Safety and efficacy profiles, steatosis, liver injury, inflammation, and fibrosis were assessed as well as mechanisms involved in MAFLD pathophysiology, namely antioxidant response, autophagy, and endoplasmic reticulum-stress.

Neither elafibranor nor S217879 had toxic effects at the tested concentrations on human PCLS with MAFLD. PPARα/δ and NRF2 target genes (pyruvate dehydrogenase kinase 4 [PDK4], fibroblast growth factor 21 [FGF21], and NAD(P)H quinone dehydrogenase 1 [NQO1], heme oxygenase 1 [HMOX1], respectively) were strongly upregulated in PCLS in response to elafibranor and S217879, respectively. Compared with untreated PCLS, elafibranor and S217879-treated slices displayed lower triglycerides and reduced inflammation (IL-1β, IL-6, chemokine (C-C motif) ligand 2 [CCL2]). Additional inflammatory markers (chemokine (C-C motif) ligand 5 [CCL5], stimulator of interferon genes [STING], intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1]) were downregulated by S217879. S217879 but not elafibranor lowered DNA damage (phospho-Histone H2A.X [p-H2A.X], RAD51, X-ray repair cross complementing 1 [XRCC1]) and apoptosis (cleaved caspase-3), and inhibited fibrogenesis markers expression (alpha smooth muscle actin [α-SMA], collagen 1 alpha 1 [COL1A1], collagen 1 alpha 2 [COL1A2]). Such effects were mediated through an improvement of lipid metabolism, activated antioxidant response and enhanced autophagy, without effect on endoplasmic reticulum-stress.

This study highlights the therapeutic potential of a new NRF2 activator for MAFLD using patient-derived PCLS supporting the evaluation of NRF2 activating strategies in clinical trials.

Oxidative stress is a major driver of metabolic-associated fatty liver disease (MAFLD) development and progression. Nuclear factor (erythroid-derived 2)-like 2, the master regulator of the antioxidative stress response, is an attractive therapeutic target for the treatment of MAFLD. This study demonstrates that S217879, a new potent and selective nuclear factor (erythroid-derived 2)-like 2 activator, displays antisteatotic effects, lowers DNA damage, apoptosis, and inflammation and inhibits fibrogenesis in human PCLS in patients with MAFLD.

Salt stress and heavy metal are instigating hazard to crops, menace to agricultural practices. Single and combined stresses affecting adversely to the growth and metabolism of plants. To explore salt and heavy metal resistant plant lines as phytoremediants is a need of time. Physiological responses are main adaptive responses of the plants towards stresses. This response varies with species and ecotype as well as type and level of stress. Two cucurbit weeds from two ecotypes were selected to evaluate their physiological adaptations against independent and combined stresses of various levels of salt (NaCl) and heavy metal (NiCl2). Various physiological parameters like water potential, osmotic potential, pressure potential, CO2 assimilation rate, stomatal conductance, chlorophyll a and b, carotenoids, and production of adaptive chemicals like SOD, CAT, proteins, sugars and proline were studied. Citrullus colocynthis showed more adaptive response than Cucumis melo agrestis and desert ecotype was more successful than agricultural ecotype against stresses.

Various intracellular pathways regulate inflammation in NASH. Cyclic GMP-AMP synthase (cGAS) is a DNA sensor that activates STING and plays a role in inflammatory diseases. Here, we explored the role of cGAS in hepatic damage, steatosis, inflammation, and liver fibrosis in mouse models of NASH.

cGAS deficient (cGAS-KO) and STING deficient (STING-KO) mice received high fat-high cholesterol-high sugar diet (HF-HC-HSD) or relevant control diets. Livers were evaluated after 16 or 30 weeks.

HF-HC-HSD diet, both at 16 and 30 weeks, resulted in increased cGAS protein expression as well as in increased ALT, IL-1β, TNF-α and MCP-1 in wild-type (WT) mice compared to controls. Surprisingly, liver injury, triglyceride accumulation, and inflammasome activation were greater in HF-HC-HSD cGAS-KO compared to WT mice at 16 and to a lesser extent at 30 weeks. STING, a downstream target of cGAS was significantly increased in WT mice after HF-HC-HSD. In STING-KO mice after HF-HC-HSD feeding, we found increased ALT and attenuated MCP1 and IL-1β expression compared to WT mice. Markers of liver fibrosis were increased in cGAS- and STING-KO mice compared to WT on HF-HC-HSD. We discovered that cGAS-KO mice had a significant increase in circulating endotoxin levels on HF-HC-HSD that correlated with changes in intestinal morphology which was exacerbated by HF-HC-HSD compared to WT mice.

Our findings indicate that cGAS or STING deficiency exacerbate liver damage, steatosis, and inflammation in HF-HC-HSD diet-induced NASH, which might be linked to the disruption of the gut barrier.

Non-Alcoholic fatty liver disease is characterized by the accumulation of excess fat in the liver, chronic inflammation, and cell death, ranging from simple steatosis to fibrosis, and finally leads to cirrhosis and hepatocellular carcinoma. The effect of Fibroblast growth factor 2 on apoptosis and ER stress inhibition has been investigated in many studies. In this study, we aimed to investigate the effect of FGF2 on the NAFLD in-vitro model in the HepG2 cell line.

The in-vitro NAFLD model was first induced on the HepG2 cell line using oleic acid and palmitic acid for 24 h and evaluated by ORO staining and Real-time PCR. The cell line was then treated with various concentrations of fibroblast growth factor 2 for 24 h, total RNA was extracted and cDNA was consequently synthesized. Real-time PCR and flow cytometry was applied to evaluate gene expression and apoptosis rate, respectively.

It was shown that fibroblast growth factor 2 ameliorated apoptosis in the NAFLD in-vitro model by reducing the expression of genes involved in the intrinsic apoptosis pathway, including caspase 3 and 9. Moreover, endoplasmic reticulum stress was decreased following upregulating the protective ER-stress genes, including SOD1 and PPARα.

FGF2 significantly reduced ER stress and intrinsic apoptosis pathway. Our data suggest that FGF2 treatment could be a potential therapeutic strategy for NAFLD.

Our study aimed to investigate the changes in hepatic endoplasmic reticulum (ER) stress, inflammation, insulin signaling, and lipid metabolism during the administration of a high-fat diet (HFD) in mice in order to identify correlations between obesity and metabolic disease development in the liver.

We used short-, medium-, and long-term HFD periods, corresponding to 4, 8, and 12 weeks, respectively, and isolated exosomes from adipose tissue. We confirmed the effect of adipose tissue-derived exosomes on metabolic disorders in obesity in alpha mouse liver 12 (AML12) hepatocytes.

Adipose tissue-derived exosomes from HFD mice did not affect the AML12 cells after 4 weeks, but ER stress, inflammatory response, insulin resistance, and lipid synthesis were observed after 8 and 12 weeks. Furthermore, we confirmed that an HFD increases the amount of adipose tissue-derived exosomes in mice. Consequently, we can infer that adipose tissue-derived exosomes from HFD-fed mice significantly increase ER stress, inflammatory response, insulin resistance, and lipid synthesis in AML12 cells.

Our results demonstrate that obesity alters the effects of adipose tissue-derived exosomes in the liver, potentially becoming a risk factor in the development of obesity-induced liver diseases.

CARF (CDKN2AIP) regulates cellular fate in response to various stresses. However, its role in metabolic stress is unknown. We found that fatty livers from mice exhibit low CARF expression. Similarly, overloaded palmitate inhibited CARF expression in HepG2 cells, suggesting that excess fat-induced stress downregulates hepatic CARF. In agreement with this, silencing and overexpressing CARF resulted in higher and lower fat accumulation in HepG2 cells, respectively. Furthermore, CARF overexpression lowered the ectopic palmitate accumulation in HepG2 cells. We were interested in understanding the role of hepatic CARF and underlying mechanisms in the development of NAFLD. Mechanistically, transcriptome analysis revealed that endoplasmic reticulum (ER) stress and oxidative stress pathway genes significantly altered in the absence of CARF. IRE1α, GRP78, and CHOP, markers of ER stress, were increased, and the treatment with TUDCA, an ER stress inhibitor, attenuated fat accumulation in CARF-deficient cells. Moreover, silencing CARF caused a reduction of GPX3 and TRXND3, leading to oxidative stress and apoptotic cell death. Intriguingly, CARF overexpression in HFD-fed mice significantly decreased hepatic steatosis. Furthermore, overexpression of CARF ameliorated the aberrant ER function and oxidative stress caused by fat accumulation. Our results further demonstrated that overexpression of CARF alleviates HFD-induced insulin resistance assessed with ITT and GTT assay. Altogether, we conclude that excess fat-induced reduction of CARF dysregulates ER functions and lipid metabolism leading to hepatic steatosis.