MicroRNA profiling reveals dysregulated microRNAs and their target gene regulatory networks in cemento‐ossifying fibroma

Background

Cemento‐ossifying fibroma (COF) is a benign fibro‐osseous neoplasm of uncertain pathogenesis, and its treatment results in morbidity. MicroRNAs (miRNA) are small non‐coding RNAs that regulate gene expression and may represent therapeutic targets. The purpose of the study was to generate a comprehensive miRNA profile of COF compared to normal bone. Additionally, the most relevant pathways and target genes of differentially expressed miRNA were investigated by in silico analysis.

Methods

Nine COF and ten normal bone samples were included in the study. miRNA profiling was carried out by using TaqMan® OpenArray® Human microRNA panel containing 754 validated human miRNAs. We identified the most relevant miRNAs target genes through the leader gene approach, using STRING and Cytoscape software. Pathways enrichment analysis was performed using DIANA‐miRPath.

Results

Eleven miRNAs were downregulated (hsa‐miR‐95‐3p, hsa‐miR‐141‐3p, hsa‐miR‐205‐5p, hsa‐miR‐223‐3p, hsa‐miR‐31‐5p, hsa‐miR‐944, hsa‐miR‐200b‐3p, hsa‐miR‐135b‐5p, hsa‐miR‐31‐3p, hsa‐miR‐223‐5p and hsa‐miR‐200c‐3p), and five were upregulated (hsa‐miR‐181a‐5p, hsa‐miR‐181c‐5p, hsa‐miR‐149‐5p, hsa‐miR‐138‐5p and hsa‐miR‐199a‐3p) in COF compared to normal bone. Eighteen common target genes were predicted, and the leader genes approach identified the following genes involved in human COF: EZH2, XIAP, MET and TGFBR1. According to the biology of bone and COF, the most relevant KEGG pathways revealed by enrichment analysis were proteoglycans in cancer, miRNAs in cancer, pathways in cancer, p53‐, PI3K‐Akt‐, FoxO‐ and TGF‐beta signalling pathways, which were previously found to be differentially regulated in bone neoplasms, odontogenic tumours and osteogenesis.

Conclusion

miRNA dysregulation occurs in COF, and EZH2, XIAP, MET and TGFBR1 are potential targets for functional analysis validation.     

Altered expression of miR-21, miR-125b, and miR-203 indicates a role for these microRNAs in oral lichen planus

J Oral Pathol Med (2012) 41 : 90–95 Background: Oral lichen planus (OLP), which is a chronic inflammatory disease of the oral mucosa with unknown etiology, affects about 2% of the population. MicroRNAs are small non‐coding RNAs involved in normal processes such as development and differentiation as well as progression of human diseases. The aim of this study was to investigate the expression of miR‐21, miR‐125b, and miR‐203 and to compare RNA levels of their potential targets, the tumor suppressor p53 and its relative p63, both known to be deregulated in OLP. Methods: In biopsies from 20 patients with OLP and 20 age‐ and sex‐matched healthy controls, epithelium was laser dissected and analyzed for the expression of miR‐21, miR‐125b, miR‐203, p53, and p63 using qRT/PCR. Results: Increased expression of miR‐21 and miR‐203, decreased expression of miR‐125, and down‐regulation of p53 and ΔNp63 RNA were seen in OLP compared to normal oral mucosa. When comparing microRNA expression to levels of p53 and p63 RNA, a significant negative correlation was seen between ΔNp63 and miR‐203 and between miR‐21 and p53, respectively. Conclusion: Results indicate a role for the studied microRNAs in changes seen in OLP.     

口腔扁平苔藓相关microRNAs的研究进展

口腔扁平苔藓(oral lichen planus,OLP)是一种常见的病因不明的慢性炎症性疾病,细胞介导的局部免疫应答紊乱在其中发挥着重要作用。目前发现microRNAs(miRNAs)在炎性反应、自身免疫性疾病的发生发展中起到重要作用,已有大量研究报道显示miRNAs可能与OLP相关。文献复习结果表明,miRNA?19a高表达和miRNA?122、miRNA?199、miRNA?138、miRNA?635、miRNA?578低表达可能通过调控白介素、干扰素、肿瘤坏死因子等细胞因子而与OLP的发生相关;miRNA?125a低表达和miRNA?132、miRNA?146a、miRNA?155高表达可能通过影响CD4^+T细胞在Th1/Th2亚群上的分化过程而与OLP的严重程度相关;miRNA?26a、miRNA?29a、miRNA?31高表达和miRNA?27b、miRNA?200a、miRNA?137低表达可能通过具有功能关系的相关基因组、转录因子和miRNA协同调控网络等与OLP癌变风险相关。目前研究仍存在不足之处,许多利用基因芯片筛选差异表达miRNA的研究并没有根据OLP类型或癌变风险进一步的分组探究。     

MicroRNA‐137 promoter methylation in oral lichen planus and oral squamous cell carcinoma

Oral lichen planus (OLP) is a common oral mucosal disease, which is generally considered a potentially malignant lesion. To identify efficiently prognostic biomarker, we investigated the microRNA‐137 (miR‐137) promoter methylation in OLP and compared with the samples from healthy volunteers and patients with oral squamous cell carcinoma (OSCC). A total of 20 OLP and 12 patients with OSCC as well as 10 healthy subjects were subjected to miR‐137 promoter methylation analysis using methylation‐specific PCR (MSP). To address the malignancy prediction potential from miR‐137 promoter methylation status, methylation of the p16 gene, a well‐known tumor suppressor, was investigated in the same samples. The p16 methylation and miR‐137 promoter methylation were found to be 25% and 35% in patients with OLP, 50% and 58.3% in patients with OSCC, and 0% and 0% in healthy subjects, respectively. The differences between miR‐137 and p16 methylation levels were statistically significant between healthy controls and patients. Methylation levels of the two promoters were also influenced by age, gender, and lesion duration. Interestingly, aberrant promoter methylation of the p16 and miR‐137 genes was only found in the epithelium but not in the connective tissue from patients with OLP. This raises the possibility to use miR‐137 methylation as a biomarker for malignant prediction in patients with OLP.     

Analysis of the expression of heat‐shock protein 27 in patients with oral lichen planus

Oral Diseases (2012) 19 , 65–72 Objective: Heat‐shock protein 27 (hsp27) has been implicated in several biological events. In this experimental study, we aimed at analysing, for the first time, the expression of hsp27 in the diverse stages of oral lichen planus (OLP) lesions. Materials and methods: Thirty‐six biopsy specimens of patients with OLP and 10 of healthy patients were selected. OLP specimens were divided into three groups: G1 – moderate or mildly active OLP; G2 – active or moderately active atrophic OLP; G3 – mild or inactive atrophic OLP. Hsp27 expression was analysed by immunohistochemistry (staining intensity and percentage of stained cells), and results of staining were compared between the different groups. Gender, age and anatomical location were also studied. Results: In the basal layer, an increase of hsp27 expression in both G2 and G3 was observed when compared to G1 and control group. In contrast, a decrease of hsp27 expression in the superficial layer was observed in all groups when compared to control group. Conclusion: The increased expression of Hsp27 in the basal layer observed during the OLP evolution and the less staining in the superficial layers in all cases of OLP suggest that hsp27 may have a role in the OLP pathogenesis.     

miR‐181 as a putative biomarker for lymph‐node metastasis of oral squamous cell carcinoma

J Oral Pathol Med (2011) 40 : 397–404 Background: Oral squamous cell carcinoma (OSCC) is an important malignant disease around the world. Aberrant expression of MicroRNAs (miRNAs) has been implicated in carcinogenesis of various cancers. In previous studies, up‐regulation of miR‐181 was observed when OSCC progressed from leukoplakia, dysplasia to invasive carcinoma. However, the function of miR‐181 in oral tumorigenesis remains unclear. Materials and methods: The expression levels of miR‐181 in the tissue and plasma of OSCC patients were measured by quantitative RT‐PCR. The correlation between miR‐181 level and multiple clinical variables were then checked by Mann–Whitney test and Wilcoxon matched pairs test. To study the functional meaning of up‐regulated miR‐181, migration assay and invasion assay by transwells and colony forming assay were applied to analyze the tumorigenic phenotypes of OSCC cells with ectopical expression of miR‐181. Results: Among different clinical variables, over‐expression of miR‐181 was correlated with lymph‐node metastasis, vascular invasion, and a poor survival. Functional assays revealed ectopically over‐expressed miR‐181 would enhance cell migration and invasion, but not the ability of anchorage‐independent growth of OSCC cells. In addition, the up‐regulation of miR‐181 could be detected both in tumor tissues and plasma. Conclusion: miR‐181 may enhance lymph‐node metastasis through regulating migration, which could potentially be exploited as a putative biomarker for patients with OSCC.     

miR-155、miR-146a在口腔扁平苔藓患者外周血和组织中的变化与相关性研究

目的 探讨miRNA（miR-155、miR-146a及miR-146b）在口腔扁平苔藓（oral lichen planus, OLP）患者外周血及病损组织中的表达及其与OLP临床特征的关系,为进一步探讨OLP的发病机制提供参考。方法 采用荧光定量PCR法,以U6基因为内参,分别检测OLP患者外周血及病损组织、健康对照外周血及组织中miR-155、miR-146a及miR-146b的相对含量。采用SPSS17.0软件包对数据进行统计学分析。结果 荧光定量PCR检测显示,与正常对照组相比,外周血 miR-155 表达水平在OLP 患者中显著增高, 病损组织中升高更加明显（组织中miR-155水平是外周血中的7.0倍）;而OLP患者外周血中miR-146a、miR-146b含量与对照组相比无显著差异（P=0.218,P=0.229）,但OLP患者病损组织中miR-146a表达升高,显著高于对照组（P=0.003）,且组织中miR-146a水平是外周血中的5倍。相关性分析结果显示,外周血中miR-155的表达水平与REU计分呈高度正相关（相关系数R=0.887,P<0.01）。结论 OLP患者外周血和组织中miR-155、miR-146a异常变化表明,miR-155、miR-146a可能与OLP的发生与演进有关,OLP可能是以局部炎症为主的慢性炎症性疾病。     

Increase of microRNA miR‐31 level in plasma could be a potential marker of oral cancer

Oral Diseases (2010) 16 , 360–364 Backgrounds: Oral squamous cell carcinoma (OSCC) is a worldwide disease. MicroRNAs are endogenously expressed non‐coding RNAs that have important biological and pathological functions. miR‐31 was found markedly up‐regulated in OSCC and several other malignancies. However, miR‐31 expression was also down‐regulated in the metastasis process of breast carcinoma. Materials and methods: Using quantitative RT‐PCR analysis, we identified plasma miR‐31 in OSCC patients (n = 43) and case controlled individuals (n = 21). Nine OSCC patients saliva were also analyzed. The Mann–Whitney test and Wilcoxon matched pairs test were used to compare the differences among the various clinical variants. Results: miR‐31 in plasma was significantly elevated in OSCC patients relative to age and sex‐matched control individuals. This marker yielded a receiver operating characteristic curve area of 0.82 and an accuracy of 0.72 defined by leave‐one‐out cross‐validation. In addition, the plasma miR‐31 in patients was remarkably reduced after tumor resection suggesting that this marker is tumor associated. Our preliminary analysis also demonstrated the feasibility of detecting the increase of miR‐31 in patient’s saliva. Conclusion: This study concluded that plasma miR‐31 could be validated a marker of OSCC for diagnostic uses.     

No detection of TSH or TSHR in oral lichen planus lesions in patients with or without hypothyroidism

Abstract

Objective: An association between hypothyroidism (HT) and oral lichen planus (OLP) has been reported. However, the mechanisms that could explain this association remain unresolved. This study aimed to evaluate the expression of thyroid-stimulating hormone (TSH) and thyroid-stimulating hormone receptor (TSHR) in healthy oral mucosa and in OLP lesions of individuals with and without HT.

Material and methods: Immunohistochemical expression of TSH and TSHR was studied in oral mucosal biopsies obtained from 14 OLP patients with HT, 14 OLP patients without HT and 10 healthy controls without oral mucosal lesions. Gene expression of TSHR was investigated by using three different PCR techniques in oral mucosal samples from 7 OLP patients with HT, 3 OLP patients without HT, 9 healthy controls and in cultured human oral epithelial cells. Gene expression of TSH was examined by employing 2 PCR techniques in oral mucosal samples from 2 OLP patients with HT, 2 OLP patients without HT and 4 healthy controls.

Results: TSH and TSHR stainings were negative in the studied oral mucosal specimens. Gene quantification assays demonstrated negative gene expression of TSH and TSHR in clinical and in vitro samples.

Conclusions: These results suggest that TSH and TSHR may not be commonly involved in the pathogenetic mechanism that could explain the association between OLP and hypothyroidism.     

Identification of potential therapeutic target genes,key miRNAs and mechanisms in oral lichen planus by bioinformatics analysis

The study aimed to identify the potential target genes and key miRNAs as well as to explore the underlying mechanisms in the pathogenesis of oral lichen planus (OLP) by bioinformatics analysis. The microarray data of GSE38617 were downloaded from Gene Expression Omnibus (GEO) database. A total of 7 OLP and 7 normal samples were used to identify the differentially expressed genes (DEGs) and miRNAs. The DEGs were then performed functional enrichment analyses. Furthermore, DEG-miRNA network and miRNA-function network were constructed by Cytoscape software. Total 1758 DEGs (598 up- and 1160 down-regulated genes) and 40 miRNAs (17 up- and 23 down-regulated miRNAs) were selected. The up-regulated genes were related to nuclear factor-Kappa B (NF-κB) signaling pathway, while down-regulated genes were mainly enriched in the function of ribosome. Tumor necrosis factor (TNF), caspase recruitment domain family, member 11 (CARD11) and mitochondrial ribosomal protein (MRP) genes were identified in these functions. In addition, miR-302 was a hub node in DEG-miRNA network and regulated cyclin D1 (CCND1). MiR-548a-2 was the key miRNA in miRNA-function network by regulating multiple functions including ribosomal function. The NF-κB signaling pathway and ribosome function may be the pathogenic mechanisms of OLP. The genes such as TNF, CARD11, MRP genes and CCND1 may be potential therapeutic target genes in OLP. MiR-548a-2 and miR-302 may play important roles in OLP development.     

Evaluation of MicroRNA‐146a and Its Targets in Gingival Tissues of Patients With Chronic Periodontitis

Background: MicroRNAs (miRNAs) are a group of small non‐coding RNAs that play an important role in the regulation of gene expression. miRNA‐146a (miR‐146a), a member of the miR‐146 family, is involved in the control of inflammation. Periodontitis is a set of chronic inflammatory disorders of the tissues surrounding the teeth that lead to the breakdown of alveolar bone and tooth loss. In this study, expression levels of miR‐146a and its targets, including tumor necrosis factor (TNF)‐α, interleukin (IL)‐1β, and IL‐6, are evaluated in human patients with chronic periodontitis (CP). Methods: The study population consisted of 10 healthy controls and 20 individuals with CP. For each participant, clinical parameters including probing depth and clinical attachment level were measured, and a gingival tissue sample was collected. Levels of miR‐146a, TNF‐α, IL‐1β, and IL‐6 were quantified using real‐time polymerase chain reaction. Results: Levels of miR‐146a were significantly higher in patients with CP (P <0.001). There was a positive correlation between levels of miR‐146a and clinical parameters (P <0.05). Elevated miR‐146a was accompanied by a significant reduction in TNF‐α and IL‐6 (P <0.001). Conclusions: Patients with CP had higher levels of miR‐146a than healthy individuals, accompanied by reduced levels of TNF‐α and IL‐6. A positive relationship between miR‐146a levels and clinical parameters suggests a pathophysiologic role of miR‐146a in CP.     

Salivary Interleukin‐6 and ‐8 in Patients With Oral Cancer and Patients With Chronic Oral Inflammatory Diseases

Background: Previous research has indicated that salivary interleukin (IL)‐6 and IL‐8 are potential biomarkers for oral squamous cell carcinoma (OSCC). However, their levels have been found to be significantly elevated in patients with chronic periodontitis (CP) or oral lichen planus (OLP). The data also showed wide variations in levels among the different studies, and no standardization procedure was ever performed. Therefore, the objective of this study is to determine whether CP or OLP confounds the use of IL‐6 or IL‐8 for OSCC detection. Methods: Saliva samples were collected from five groups: OSCC before treatment (n = 18); CP (n = 21); disease‐active OLP (n = 21); disease‐inactive OLP (n = 20); and healthy controls (n = 21). IL‐6 and IL‐8 concentrations (determined by enzyme‐linked immunosorbent assays) were compared, using total salivary protein–standardized levels to validate the data. The Kruskal–Wallis test (α = 0.05) followed by pairwise Mann–Whitney U (post hoc) tests with Bonferroni adjustments (α = 0.00625) were used for statistical analysis. Results: Salivary IL‐6 levels were significantly higher in patients with OSCC than in patients with CP (P <0.001), disease‐active OLP (P = 0.001), disease‐inactive OLP (P <0.001), and healthy controls (P <0.001). Salivary IL‐8 levels were significantly higher in patients with OSCC than in patients with CP (P <0.001), but only marginally significantly higher than in healthy controls (P = 0.014). Statistical results of standardized IL‐6 and IL‐8 levels were consistent with the non‐standardized levels in all pairs except one. Conclusion: Salivary IL‐6 may be a useful biomarker in the detection of OSCC, unconfounded by CP or OLP.     

Anti‐angiogenic therapy (bevacizumab) in the management of oral lichen planus

Oral lichen planus (OLP), a mucocutaneous chronic inflammatory disease, is conventionally managed using topical corticosteroid therapy. Given the fact that OLP is strongly linked to angiogenesis, anti‐angiogenic drugs, such as bevacizumab, might be introduced as an alternative treatment for contraindicated, non‐responsive patients. The aim of the present study was to report the short‐term effectiveness and safety of intralesional bevacizumab injection in the management of atrophic/erosive OLP. A case series study was conducted in patients with atrophic/erosive OLP in the buccal mucosa, assigned to receive either 2.5 mg of bevacizumab, by intralesional injection (n = 20, test), or topical 0.1% triamcinolone acetonide ointment (n = 20, control). The size, score, and pain intensity of the lesions were assessed pre‐ and post‐treatment. Tissue biopsies were collected for histopathologic, immunohistochemical, and ultrastructural examination. After 1 wk, the test group had significant reductions both in lesion seize and in pain scores compared with controls. A marked decrease in vascular endothelial growth factor (VEGF) and interleukin‐8 immunoexpression was noted in tissue biopsies from bevacizumab‐treated lesions compared with control lesions. Furthermore, ultrastructural examination of OLP tissue specimens revealed significant healing signs associated with bevacizumab treatment. Short‐term data suggest that intralesional bevacizumab injection effectively and safely achieved resolution of atrophic/erosive OLP lesions without disease exacerbations during a 3‐month follow‐up period.     

Elevated MicroRNA‐128 in Periodontitis Mitigates Tumor Necrosis Factor‐α Response via p38 Signaling Pathway in Macrophages

Background: Periodontitis is a chronic inflammatory disease resulting from an inflammatory response to subgingival plaque bacteria, including Porphyromonas gingivalis. MicroRNA (miRNA) is a current focus in regulating the inflammatory processes. In this study, the inflammatory miRNA expression in gingival tissues of patients with periodontitis and of healthy individuals is compared, and its role in regulating the inflammatory response is examined. Methods: Gingival tissues from patients with periodontitis and healthy individuals were collected for miRNA microarray. THP‐1 and CA9‐22 cells were challenged with P. gingivalis, and miRNA expression was determined by real‐time polymerase chain reaction. Target genes for miRNA were predicted using TargetScanHuman database, and miRNA gene expressions were reviewed using public databases. For the functional study, THP‐1 cells were transfected with a miRNA‐128 mimic, and target gene expression was compared with THP‐1 cells challenged with P. gingivalis. For the tolerance test, THP‐1 cells transfected with miRNA‐128 mimic were treated with phorbol 12‐myristate 13‐acetate (PMA) or paraformaldehyde (PFA)‐fixed Escherichia coli. Tumor necrosis factor (TNF)‐α production was determined by enzyme‐linked immunosorbent assay, and mitogen‐activated protein kinase (MAPK) protein phosphorylation was determined by Western blot. Results: Gingival tissues from patients with periodontitis showed increased expression of miRNA‐128, miRNA‐34a, and miRNA‐381 and decreased expression of miRNA‐15b, miRNA‐211, miRNA‐372, and miRNA‐656. THP‐1 cells and CA9‐22 cells challenged with P. gingivalis showed increased miRNA‐128 expression. Among the predicted miRNA‐128 target genes, several genes that are involved in MAPK signaling pathway showed similar gene expression pattern between P. gingivalis challenge and miRNA‐128 mimic transfection. In THP‐1 cells transfected with miRNA‐128 mimic, TNF‐α production was lower, and phosphorylation of p38 was inhibited when challenged with PMA or PFA‐fixed E. coli. Conclusion: miRNA‐128 may be involved in mitigating the inflammatory response induced by P. gingivalis in periodontitis.     

Changes in miRNA expression in sera and correlation to duration of disease in patients with multifocal mucosal lichen planus

J Oral Pathol Med (2012) 41 : 86–89 Background: Mucosal lichen planus is a severe variant of lichen planus, Lichen planus (LP), which in many ways affect patients’ lives. The aetiology is not fully understood, and there is no treatment clearing the disease once and for all. Oral LP has by the WHO been classified as a precancerous lesion. Micro‐RNAs, miRNAs, are non‐coding, small single‐stranded RNAs involved in biological processes like apoptosis, proliferation, differentiation, metastasis, angiogenesis and immune response. Methods and Results: In sera from 30 patients with multifocal mucosal LP, 15 miRNAs were identified as significantly differentially expressed compared with controls. The three most up‐regulated miRNAs are all connected to oral squamous cell carcinoma or epithelial carcinoma in general. Discussion: Even if no specific LP‐associated miRNA profile was found, data clearly indicate that miRNAs could play a role in the earlier phases of lichen planus.     

PerioGlas® Regulates Osteoblast RNA Interfering

Purpose: PerioGlas^® (PG) is an alloplastic material that has been used for grafting periodontal osseous defects since the 1990s. In animal models, it has been proven that PG achieves histologically good repairs of surgically created defects. In clinical trials, PG is effective as an adjunct to conventional surgery in the treatment of intrabony defects; however, how PG alters osteoblast activity to promote bone formation is poorly understood. We therefore attempted to address this question by using microRNA (miRNA) microarray techniques to investigate the translation process in osteoblasts exposed to PG. Materials and Methods: By using miRNA microarrays containing 329 probes designed from human miRNA sequences, we identified several miRNA whose expression was significantly modified in osteoblast‐like cell lines (MG‐63) cultured with PG. Results: There were ten up‐regulated miRNA (mir‐337, mir‐377, mir‐9, mir‐516, mir‐515‐3p, mir‐496, mir‐200b, mir‐489, mir‐25, mir‐423) and two down‐regulated miRNA (mir‐26a, mir‐30d). Conclusion: PG acts on miRNAs, which in turn regulate several messengers. Among them there are mRNAs related to bone formation and skeletal and cartilage development. The vast majority of detected genes are down‐regulated, and some are homeobox genes like NOG, EN1, and CHRD. Other down‐regulated genes are receptors (like GHRHR) and extracellular matrix proteins (like COMP). Although the exact mechanism of PG action on osteoblasts is still incompletely understood, these data demonstrate that PG has not only an osteoconductive effect, but also regulates bone formation.     

miR‐140‐5p‐mediated regulation of the proliferation and differentiation of human dental pulp stem cells occurs through the lipopolysaccharide/toll‐like receptor 4 signaling pathway

Human dental pulp stem cells (DPSCs) are oral mesenchymal stem cells with potential to differentiate into various cell types. Recent studies of DPSCs have focused on microRNAs (miRNAs), a class of small noncoding RNAs that play crucial roles in regulating DPSC phenotypes. In the current study, the expression of miR‐140‐5p was significantly decreased during lipopolysaccharide (LPS)‐mediated differentiation of DPSCs in vitro. Overexpression of miR‐140‐5p enhanced proliferation of DPSCs and inhibited DPSC differentiation, whereas suppression of miR‐140‐5p produced the opposite effect. Moreover, the expression of toll‐like receptor 4 (TLR‐4), a critical regulator of DPSCs, was negatively correlated with the levels of miR‐140‐5p. A luciferase reporter analysis confirmed that miR‐140‐5p could regulate TLR‐4 by directly binding to the 3′‐untranslated region (3′‐UTR) of the TLR4 mRNA. Additionally, we suppressed TLR‐4 expression by treating cells with a TLR‐4 inhibitor, CLI‐095, and demonstrated that the effect of the miR‐140‐5p inhibitor on DPSC proliferation and differentiation could be partially reversed by blocking TLR‐4. Taken together, our data suggest that miR‐140‐5p is a novel miRNA that regulates DPSC proliferation and differentiation.