Proteomic profiling of various human dental stem cells - a systematic review

Table 1 Proteomic analysis of individual human dental stem cells

Ref.	Human dental stem cells analyzed	Method used	Main findings	Inference
Morsczeck et al[30]	Dental follicle precursor cells	2-DE combined with LC-MS/MS Bioinformatic analyses	Differentially regulated proteins: 115 upregulated proteins: Glutamine synthetase, lysosomal proteinase cathepsin B Proteins, plastin 3 t-isoform, beta-actin, superoxide dismutases, and transgelin Highly downregulated proteins: Cofilin-1, pro-alpha 1 collagen, destrin, prolyl 4-hydrolase and dihydrolipoamide dehydrogenase Upregulated proteins Downregulated proteins	Actin-bundling and defense against Oxidative cellular stress Collagen biosynthesis Catabolism, cell motility and biological quality Cell cycle progression and protein metabolism
Pivoriunas et al[15]	Human dental pulp derived SHEDs	2-DE and MALDI-TOF-MS	The protein spot designs imagined on 2-DE gels were entirely replicable, and roughly 150–300 protein spots were distinguished on each gel The cells communicated trademark antigens of MSC-like cells, including CD73, CD90, CD105, CD146, and did not express hematopoietic markers CD14, CD34, and CD45, as surveyed with FACS examination	Identification of profoundly communicated proteins in SHEDs uncovered proteomic profiles fundamentally the same as that of MSC-like cells got from different tissues
Niehage et al[10]	hPDLSCs	LC-MS/MS	400 cell surface proteins were recognized Prominently, a few proteins affiliated with the tumor necrosis factor receptor super family (CD40, CD120a, CD261, CD262, CD264, and CD266), distinctive integrins (alpha-4, alpha-6, and alpha-10), or interleukin receptors (CD121a, CD130, CD213a1, CD217, and CDw210b) were distinguished	Huge, changes in the proteomes of DPSCs cultured in either low (BE medium) or high (S medium) serum content milieu
Xiong et al[25]	hPDLSCs	2-DE-MS	An aggregate of 80 very much settled proteins spots with an atomic weight scope of 10-110 kDa were recognized. Following spot extraction and investigation by MS, a sum of 32 protein spots were recognized as membrane related proteins PDLSC were likewise found to express two novel cell surface proteins, Annexin A2 and sphingosine kinase 1	These proteomic discoveries give the stage to additionally characterize the cell surface protein articulation profile of PDLSC so as to additionally describe this cell populace and support development of novel isolation and purification strategies
Wei et al[11]	hPDLSCs	2-DE coupled with MALDI-TOF MS	23 protein spots identified to the early odontogenic differentiation were distinguished; These proteins included cytoskeleton proteins, nuclear proteins, cell membrane-bound molecules, proteins involved in matrix synthesis, and metabolic enzymes; The expression of four identified proteins, which were heteronuclear ribonuclear proteins C, annexin VI, collagen type VI, and matrilin-2, was confirmed by Western blot and real-time real time polymerase chain reaction	Articulation changes of the recognized proteins uncover the inclusion of involvement of various regulation mechanisms in odontoblast-like differentiation including cell cycle, protein synthesis and degradation, Ca2+ homeostasis, signal transduction, translation, and cellular energy regulation, which are all fascinating focuses for further examinations
Wu et al[26]	Human periodontal ligament cells	2-DE combined with LC-MS/MS and peptide mass fingerprinting	61 proteins in periodontal ligament cells experiencing differentiation appeared no less than a 1.5-crease change in intensity, of which 29 differentially communicated proteins were effectively distinguished by MALDI-TOF MS The outflows of a portion of the recognized proteins were moreover confirmed stern blotting and reverse transcription–polymerase chain reaction analysis	These proteins for the most part included cytoskeleton proteins and cytoskeleton-related proteins, nuclear proteins and cell membrane bound particles, and might be related with the remarkable capacity of periodontal ligament cells in keeping up periodontal tissue homeostasis, especially in the midst of the mineralization of periodontal tendon
Gnanasegaran et al[12]	DPSCs from carious teeth	PCR Western blot analysis Impulse detection via microelectrode array	The capability of DPSCs-CT to differentiate into DAergic-like cells was not proportionate to that of DPSCs; This was also reflected in both gene and protein generation whereby key neuronal markers, for example, nestin, NURR1 and beta-III-tubulin were expressed essentially lower when contrasted with separated DPSCs; Also, articulations of transcriptomes identified with neurogenesis uncovered down control of over half of the qualities when contrasted with separated DPSC	DPSCs-CT were able to differentiate into DAergic-like cells but not as efficiently as DPSCs
Dou et al[31]	DFCs	iTRAQ labeling combined with MS	A total of 2092 transmitted proteins were distinguished in adjusted media of iDFCs. Diverged from primary DFCs, 253 unmistakably conveyed proteins were found in iDFCs secretome (142 up-managed and 111 down-controlled); Bioinformatic examination revealed that the vast majority of emitted proteins were locked in with cell process, metabolic procedure, biologic control, cell part association or biogenesis, immune framework process, formative procedure, reaction to upgrade and flagging	Proteomic profile of cell secretome wasn’t largely affected after immortalization converted by this piggyback immortalization system; The secretome of iDFCs may be a good candidate of primary DFCs for regenerative medicine
Reichenberg et al[27]	Periodontal ligament fibroblast	2-DE MALDI-TOF	900 spots were distinguished and recognized 117 protein spots originating in 74 different genes; In addition to scaffold cytoskeletal proteins, proteins implicated with cellular motility and membrane trafficking, chaperone, stress and folding proteins, metabolic enzymes, proteins associated with detoxification and membrane activity, biodegradative metabolism, translation and transduction, extracellular proteins, and cell cycle regulation proteins were recognized	Most of these identified proteins are closely related to the extensive PDL fibroblasts’ functions and homeostasis
Hao et al[28]	Periodontal ligament stem cells	Microarray	Expression of 116 miRNAs was found to be altered after osteo-induction, with 30 upregulated and 86 downregulated; Thirty-one of these miRNAs (26.7%) had osteogenesis-related target genes	Noteworthy modifications in miRNA articulation profiles were seen amid osteogenic separation of hPDLSCs; These outcomes infer that miRNAs may effectively affect this procedure by focusing on osteogenesis-related genes
Wilson et al[13]	DPSCs	High-resolution array comparative genomic hybridization	Spontaneously immortalized and hTERT immortalized DPSCs do not demonstrate tumorgenic potential	Cultured DPSC lines that can be differentiated into neurons may be safe for future in vivo therapy for neurobiological diseases
Choi et al[14]	DPSCs	Microarray	Strong expression of BBX during the odontoblast differentiation of DPSCs; The overexpression of BBX cDNA in DPSCs/progenitors induced substantial mineralization and expression of the odontoblast marker genes, such as ALP, OPN, BSP, DMP1, and DSPP	The results show that BBX plays a key role in the regulation of odontoblast differentiation of hPDLSCs/progenitors.

2-DE: Two-dimensional gel electrophoresis; SHEDs: Stem cells from human exfoliated deciduous teeth; LC: Liquid chromatography; MS: Mass spectrometry; MALDI-TOF: Matrix assisted laser desorption/ionization time-of-flight; MSC: Mesenchymal stem cells; FACS: Fluorescent-activated cell sorting; DPSCs: Dental pulp stem cells; PDLSCs: Periodontal ligament stem cells; hPDLSCs: Human PDLSCs; PCR: Polymerase chain reaction; CT: Computed tomography; iTRAQ: Isobaric tag for relative and absolute quantitation; DFCs: Dental follicle cells; iDFCs: Immortalized DFCs; PDL: Periodontal ligament; hTERT: Human telomerase reverse transcriptase.

Table 2 Comparative proteomic analysis amongst various human dental stem cells

Ref.	Human dental stem cells compared	Method used	Main findings
Taraslia et al[16]	SHEDs and PDLSCs	Nano-LC tandem-MS	SHEDs prevalently communicated atoms that are engaged with sorting out the cytoskeletal network, cell migration and adhesion, while PDLSCs are profoundly energy delivering cells, endlessly communicating proteins that are involved in different parts of cell metabolism and multiplication
Eleuterio et al[17]	Periodontal ligament and dental pulp	2-DE MALDI-TOF/TOF	DPSCs vs PDLSCs express differentially regulated proteins that are potentially related to growth, regulation and genesis of neuronal cells, suggesting that SCs derived from oral tissue source populations may possess the potential ability of neuronal differentiation which is very consistent with their neural crest origin
Patil et al[18]	Dental follicle, dental pulp and dental papilla	2DE coupled with MALDI-TOF MS	19 proteins either found commonly or differentially expressed among the three types of dental MSCs which were largely similar cellular properties and multilineage potential
Ma et al[19]	DPSCs and CDPSCs	2DE electrophoresis (2-D DIGE) in combination with (MALDI-TOF MS)	18 protein spots differentially expressed between DPSCs and CDPSCs; These differently expressed proteins are mostly involved in the regulation of cell proliferation, differentiation, cell cytoskeleton and motility. CDPSCs had a higher expression of antioxidative proteins that might protect CDPSCs from oxidative stress
Akpinar et al[20]	DPSCs from natal, exfoliated deciduous, and an impacted third molar tooth	2DE approach coupled with MALDI-TOF/TOF	61 proteins were predominantly expressed by all three stem cell types. Classification of the identified proteins based on biological function revealed that structurally important proteins and proteins that are involved in protein folding machinery are predominantly expressed by all three stem cell lines
Wang et al[21]	DPSCs and periodontal ligament stem cells	iTRAQ technique	A total of 159 differentially expressed proteins in PDLSCs and DPSCs. GO classification terms that distinguish osteo-induced PDLSCs from DPSCs were identified. two thirds of the enriched GO terms belonged to metabolic processes and response to stimulus, suggesting that PDLSCs and DPSCs may undergo distinct metabolic changes during the differentiation process and that the differentiation induction environment could act as a stress condition. Mineralization and migration capacities of PDLSCs were greater than those of DPSCs
Guo et al[32]	Dental follicle and dental papilla cells	2DE approach coupled with MALDI-TOF/TOF	12 proteins were significantly differential, and phosphoserine aminotransferase 1, isoform 2 of hypoxia-inducible factor 1-alpha and Isoform 1 of annexin A2, were the most significantly differential proteins. These proteins are related to regulation of bone balance, angiogenesis and cell survival in an anoxic environment. Both DFCs and DPCs express odontogenic, neurogenic and peridontogenic markers
Tian et al[33]	DFCs and periodontal ligament cells	2DE approach coupled with MALDI-TOF/TOF	32 differentially expressed proteins in DFCs and PDLCs. PDLCs could contribute to regenerate dentin-like tissues in the inductive microenvironment of treated dentin matrix. DFCs presented more remarkable dentinogenic capability than PDLCs
Joo et al[22]	Apical papilla and dental pulp	A cytokine membrane array and enzyme-linked immunosorbent assay	Odontoblast differentiation-related cytokines were more strongly expressed in DPSCs-CM, while cell-proliferation–related cytokines were more strongly expressed in DACCs-CM; DPSCs may exert a stronger paracrine effect than DACCs on regeneration of the dentin–pulp complex, in terms of odontoblast differentiation
Wang et al[23]	DPSCs and SHED	Flow cytometry analysis of cell surface antigens RT-qPCR Western blot analysis	Notable alterations were exhibited in SHED and DPSCs during the process of extensive expansion in vitro and the results may provide guidance for the selection of safe and effective expanded SHED and DPSCs for regenerative medicine and therapy
Li et al[29]	DFCs and periodontal ligament cells	iTRAQ	A total of 2138 proteins were identified and 39 of these proteins were consistently differentially expressed between DFCs and PDLCs. Gene ontology analyses revealed that the protein subsets expressed higher in PDLCs were related to actin binding, cytoskeletal protein binding, and structural constituent of muscle. PDLCs display enhanced actin cytoskeletal dynamics relative to DFCs while DFCs may exhibit a more robust antioxidant defense ability relative to PDLCs

SHEDs: Stem cells from human exfoliated deciduous teeth; PDLSCs: Periodontal ligament stem cells; LC: Liquid chromatography; MS: Mass spectrometry; 2-DE: Two-dimensional gel electrophoresis; MALDI-TOF: Matrix assisted laser desorption/ionization time-of-flight; SCs: Schwann cells; MSCs: Mesenchymal stem cells; DPSCs: Dental pulp stem cells; CDPSCs: Carious DPSCs; iTRAQ: Isobaric tag for relative and absolute quantitation; DFCs: Dental follicle cells; DPCs: Dental pulp cells; CM: Conditioned medium; SHEDs: Human exfoliated deciduous teeth; RT-qPCR: Real time quantitative polymerase chain reaction; iTRAQ: Isobaric tag for relative and absolute quantitation.

Table 3 Comparative proteomic analysis of human dental stem cells with other mesenchymal stem cells of the body

Ref.	Comparison		Main findings
	Dental stem cells	Mesenchymal stem cells
Kumar et al[24]	DPSCs	BMSCs	DPSCs and its secretome show an inherent tendency for higher osteogenic differentiation and lower adipogenic differentiation, these may be potential candidates for effective future therapy in osteoporosis where disturbance of osteocyte/adipocyte homeostasis is reported
Eleuterio et al[17]	DPSCs and periodontal ligament stem cells	BMSCs	Stem cells from oral tissue represent an easily accessible and autologous niche of stem cells that could give a worthwhile source to regenerative medication including many tissue frameworks and nerve repair
Yu et al[34]	Dental apical papilla	BMSCs	As for BMSCs, SCAPs indicated extended outflow of proteins that are locked in with metabolic methods and translation and lower measurements of those related with normal bond, developmental strategies, and safe limit; Similarly, SCAPs released on a very basic level greater proportions of chemokines and neurotrophins than BMSCs, however BMSCs discharged more ECM proteins and proangiogenic factors

DPSCs: Dental pulp stem cells; BMSCs: Bone marrow mesenchymal stem cells; SCAPs: Mesenchymal stem cells from dental apical papilla; ECM: Extracellular matrix.

Table 4 Proteomic studies on influence or microenvironment or preconditioning factors on human dental stem cells

Ref.	Dental stem cells	Influence of niche or microenvironment or preconditioning factors	Main findings
Dou et al[37]	DPSCs	Hypoxia	Hypoxic culture of DPSCs under 3D framework incompletely influences the proteome profile of cells. Albeit present moment hypoxic culture (1% O2 for 24 h) changed articulation of a few proteins, the in an unexpected way communicated protein represent 2.7% (57 of 2115); By and large the impact of hypoxia on protein articulation in DPSCs was not substantial
Lee et al[38]	DPSCs	Preameloblasts conditioned medium	Preameloblasts molded medium initiates the odontogenic differentiation of DPSCs and advances dentin development in vivo and in vitro Of the distinguished proteins, Cpne7 is another applicant that is engaged with odontoblast differentiation
Kim et al[39]	DPSCs	Human LOXL2	LOXL2 negatively affects the differentiation of hDPSCs and blocking LOXL2 can elevate the hDPSC differentiation to odontoblasts
Wang et al[21]	DPSCs Periodontal ligament stem cells	Osteogenic induction medium	Fewer than 5% of the differentially imparted proteins make up the close proteomic profile between osteo-induced PDLSCs and DPSCs This examination portrays the differences between osteo-induced PDLSCs and DPSCs in vitro The mineralization and migration cutoff points of PDLSCs were more noticeable than those of DPSCs, in which heat shock protein beta-1, Protein S100-A10 and S100-A11 may have an impact
Jung et al[40]	Gingival fibroblasts	Cyclosporin-A	Prx 1 may play a relevant role in CsA-induced proliferation of gingival fibroblasts
Bakopoulou et al[41]	Apical papilla mesenchymal stem cells	Stress microenvironments: Serum deprivation, glucose deprivation, and oxygen deprivation/hypoxia conditions, individually or in combination	Endothelial transdifferentiation potential as well as angiogenic paracrine activity of apical papilla mesenchymal stem cells was significantly upgraded when uncovered for a brief timeframe to combined stress microenvironments
Lin et al[42]	hPDLSCs	2,3,5,4’-tetrahydroxystilbene-2-O-β-D-glucosid	2,3,5,4’-tetrahydroxystilbene-2-O-β-D-glucosid enhanced the renewal ability and proliferative potential of hDPSCs via the AMPK/ERK/SIRT1 axis
Rani et al[43]	hPDLSCs	PVF of the horseshoe crab embryo	PVF could improve cell cycle regulatory gene expression in DPSCs as shown by the higher articulation of the considerable number of qualities considered in this investigation at various cell passages in the treated gathering contrasted with the untreated group
Laothumthut et al[44]	hPDLSCs	WSM extracted from the nacreous layer of the bivalve pinctada maxima	The human dental pulp cells cultured in nacreous WSM showed higher relative cell suitability than those in DMEM with comparative morphological appearance; Huge changes were found in the overall plenitude of 44 proteins in cells after introduction to WSM for about 14 d; They assume a job in cell adhesion, cell proliferation, metabolic process, signal transduction, stress reaction, transcription, translation, and transport
Bok et al[45]	Dental follicle derived stem cells	HUVECs	Expanded angiogenic movement in DFSC/HUVEC co-cultures may invigorate osteoblast development of DFSCs. Along these lines, the emission of angiogenic factors from HUVECs may assume a job in the osteogenic differentiation of DFSCs
Tsikandelova et al[46]	Human dental pulpal cells	FGF 8 protein	FGF8 treatment could advance endogenous recuperating of the dental mash by means of enlistment of dental pulp progenitors just as by advancing their angiogenic and odontogenic differentiation
Qin et al[47]	Human dental pulpal cells	Metformin	Metformin can incite DPC differentiation and mineralization in an AMPK-subordinate way and that this all around endured antidiabetic drug has potential in regenerative endodontics just as in other regenerative applications
Wang et al[48]	hPDLSCs	DFO	Early introduction to DFO advanced the mineralization of DPSCs and expanded autophagic action Autophagy restraint stifled DFO-prompted DPSC movement and odontoblast differentiation
Li et al[49]	hPDLSCs	SCs and its secreted vesicles	SC emission demonstrated an overwhelmingly regulatory on the development of hDPCs

DPSCs: Dental pulp stem cells; LOXL2: Lysyl oxidase like 2; hDPSC: Human dental pulp stem cells; PDLSCs: Periodontal ligament stem cells; hPDLSCs: Human PDLSCs; PVF: Perivitelline fluid; WSM: Water-soluble matrix; HUVECs: Human umbilical vein endothelial cells; DFSC: Dental follicle stem cells; DPCs: Dental pulp cells; DFO: Deferoxamine; SC: Schwann cell; hDPCs: Human dental pulp cells.

Table 5 Phenotypic cell surface markers in dental stem cells

Ref.	Dental stem cells	Mesenchymal stromal cell markers			Hematopoietic (stem) cell markers
		Positive	Negative		Positive	Negative
Niehage et al[10]		CD29, CD44, CD73, CD90, CD105, CD146, CD166	CD271		CD 34, CD 45, CD133,CD117
Choi et al[14]	DPSCs	CD29, CD44, CD105 and CD90
Pivoriuunas et al[15]	SHEDs	CD73, CD90, CD105, CD146					CD14, CD34, and CD45
Taraslia et al[16]	SHEDs and PDLSCs	CD73, CD90 & CD105					CD45, CD34 and CD31
Eleuterio et al[17]	PDLSCs and DPSCs	CD13+, CD29+, CD44+,CD105+, CD73+, CD90+, CD146+, CD166+					CD117, CD133, CD144, CD271, CD14, CD34, CD45
Patil et al[18]	DPSCs, APSCs and DFSCs	CD44, CD73, CD90 & vimentin markers specifically associated with MSCs.			A few cells expressed CD34 and CD45 markers associated with hematopoietic cells
Akpinar et al[20]	DPSCs of SHED, Natal teeth and impacted third molar	CD3, CD4, CD13, CD14, CD29, CD34, CD44, CD45, CD73, CD90, CD106, CD117, CD146, CD166, HLA-DR, and HLA-ABC
Wang et al[21]	SHEDs and DPSCs	CD73, CD90 and CD105			Low expression of CD34, CD11b, CD19, CD45 and HLA-DR
Kumar et al[24]	DPSCs	CD73, CD90 and CD105					CD34 and CD45
Xiong et al[25]	PDLSCs	CD 73 and CD 90
Wu et al[26]	PDLSCs	STRO-1, CD146, CD29, CD44 and CD106					CD34
Hao et al[28]	PDLSCs	STRO-1, CD146, CD29 and CD90					CD31, CD34, CD45 and CD106
Li et al[29]	DFSCs and PDLSCs	CD73 and CD 90					CD31, CD34 and CD45, HLA-DR
Dou et al[31]		CD73, CD90, and CD146					CD34, CD45
Guo et al[32]	DPSCs and DFSCs	STRO-1, CD29, CD44, CD90 and CD146			DPSCs: CD146 and CD106		CD31
Tian et al[33]	DFSCs and PDLSCs	CD146 and STRO-1: Higher in DFSCs, CD105, CD90, CD44 and CD29					CD 31, CD34 and CD45
Yu et al[34]	APSCs	CD73, CD90, CD105 and CD146					CD34
Dou et al[37]	DPSCs	CD73, CD90, and CD146					CD34 and CD45
Lee et al[38]	DPSCs	STRO-1 and CD44
Kim et al[39]	DPSCs	CD44, CD73, and CD105					CD34
Bakopoulou et al[41]		CD90/Thy-1, CD73, CD146/MUC18, CD81/TAPA and the cell adhesion molecules CD49f/a6-integrin, CD29/b1-integrin, CD51/av-integrin, and CD166/ALCAM. Lower expression: STRO-1 (22.6%–2.2%), CD24 (25.8%–1.9%), and CD34 (3.2%–0.5%)			CD105 and CD106		CD45
Bok et al[45]	DFSCs	CD44, CD73, CD90 and CD105					CD34 and CD45
Tsikandelova et al[46]	DPSCs	CD49f, CD117, CD146, CD271, CD105 and Stro-1
Qin et al[47]		CD73, CD90 and CD105					CD34 and CD45

DPSCs: Dental pulp stem cells; SHEDs: Stem cells from human exfoliated deciduous teeth; PDLSCs: Periodontal ligament stem cells; APSCs: Stem cells from apical papilla; DFSCs: Dental follicle stem cells; MSCs: Mesenchymal stem cells.