scholarly journals Mechanical Stress Modulates the RANKL/OPG System of Periodontal Ligament Stem Cells via α7 nAChR in Human Deciduous Teeth: An In Vitro Study

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Yujiang Chen ◽  
Kuan Yang ◽  
Zhifei Zhou ◽  
Lulu Wang ◽  
Yang Du ◽  
...  

The aim of this study was to investigate the mechanism by which periodontal ligament stem cells (PDLSCs) modulate root resorption of human deciduous teeth under mechanical stress. In this investigation, the PDLSCs were derived from deciduous and permanent teeth at different stages of root resorption. A cyclic hydraulic pressure was applied on the PDLSCs to mimic chewing forces in the oral environment. The cultured cells were characterized using osteogenic and adipogenic differentiation assays, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting analysis. The PDLSCs exhibited the ability to induce osteoclast differentiation under certain mechanical stresses. As the expressions of RUNX2, alkaline phosphatase (ALP), and osteoprotegerin (OPG) were significantly reduced, the receptor activator of the nuclear factor kappa-B ligand (RANKL) was upregulated increasing the RANKL/OPG ratio. Under hydrodynamic pressure at 0-135 kPa, the expressions of alpha 7 nicotinic acetylcholine receptors (α7 nAChR), p-GSK-3β, and active-β-catenin were markedly upregulated in PDLSCs from unresorbed deciduous teeth. Treatment with the α7 nAChR inhibitor alpha-bungarotoxin (α-BTX) and the Wnt pathway inhibitor DKK1 may reverse the mechanical stress inducing upregulation of RANKL and reduction of RUNX2, ALP, and OPG. Alizarin red staining confirmed these results. The mechanical stress applied on the deciduous tooth PDLSCs can induce osteoclastic effects through upregulation of α7 nAChR and activation of the canonical Wnt pathway. It can be suggested that chewing forces may play a major role at the beginning of the physiological root resorption of deciduous teeth.

2020 ◽  
Vol 11 (9) ◽  
Author(s):  
Qian Li ◽  
Xiwen Sun ◽  
Yunyi Tang ◽  
Yanan Qu ◽  
Yanheng Zhou ◽  
...  

Abstract Despite the ubiquitous mechanical cues at both spatial and temporal dimensions, cell identities and functions are largely immune to the everchanging mechanical stimuli. To understand the molecular basis of this epigenetic stability, we interrogated compressive force-elicited transcriptomic changes in mesenchymal stem cells purified from human periodontal ligament (PDLSCs), and identified H3K27me3 and E2F signatures populated within upregulated and weakly downregulated genes, respectively. Consistently, expressions of several E2F family transcription factors and EZH2, as core methyltransferase for H3K27me3, decreased in response to mechanical stress, which were attributed to force-induced redistribution of RB from nucleoplasm to lamina. Importantly, although epigenomic analysis on H3K27me3 landscape only demonstrated correlating changes at one group of mechanoresponsive genes, we observed a genome-wide destabilization of super-enhancers along with aberrant EZH2 retention. These super-enhancers were tightly bounded by H3K27me3 domain on one side and exhibited attenuating H3K27ac deposition and flattening H3K27ac peaks along with compensated EZH2 expression after force exposure, analogous to increased H3K27ac entropy or decreased H3K27ac polarization. Interference of force-induced EZH2 reduction could drive actin filaments dependent spatial overlap between EZH2 and super-enhancers and functionally compromise the multipotency of PDLSC following mechanical stress. These findings together unveil a specific contribution of EZH2 reduction for the maintenance of super-enhancer stability and cell identity in mechanoresponse.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Tingting Meng ◽  
Ying Zhou ◽  
Jingkun Li ◽  
Meilin Hu ◽  
Xiaomeng Li ◽  
...  

Background and Objective. This study investigated the effects and underlying mechanisms of azithromycin (AZM) treatment on the osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) after their stimulation with TNF-α in vitro. Methods. PDLSCs were isolated from periodontal ligaments from extracted teeth, and MTS assay was used to evaluate whether AZM and TNF-α had toxic effects on PDLSCs viability and proliferation. After stimulating PDLSCs with TNF-α and AZM, we analyzed alkaline phosphatase staining, alkaline phosphatase activity, and alizarin red staining to detect osteogenic differentiation. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis was performed to detect the mRNA expression of osteogenic-related genes, including RUNX2, OCN, and BSP. Western blotting was used to measure the NF-κB signaling pathway proteins p65, phosphorylated p65, IκB-α, phosphorylated IκB-α, and β-catenin as well as the apoptosis-related proteins caspase-8 and caspase-3. Annexin V assay was used to detect PDLSCs apoptosis. Results. TNF-α stimulation of PDLSCs decreased alkaline phosphatase and alizarin red staining, alkaline phosphatase activity, and mRNA expression of RUNX2, OCN, and BSP in osteogenic-conditioned medium. AZM enhanced the osteogenic differentiation of PDLSCs that were stimulated with TNF-α. Western blot analysis showed that β-catenin, phosphorated p65, and phosphorylated IκB-α protein expression decreased in PDLSCs treated with AZM. In addition, pretreatment of PDLSCs with AZM (10 μg/ml, 20 μg/ml) prevented TNF-α-induced apoptosis by decreasing caspase-8 and caspase-3 expression. Conclusions. Our results showed that AZM promotes PDLSCs osteogenic differentiation in an inflammatory microenvironment by inhibiting the WNT and NF-κB signaling pathways and by suppressing TNF-α-induced apoptosis. This suggests that AZM has potential as a clinical therapeutic for periodontitis.


2021 ◽  
Author(s):  
Feng Zhou ◽  
Jia Guo ◽  
Fang Wang ◽  
Wanmin Zhao ◽  
Xiaoning He ◽  
...  

Abstract Background: Periodontal ligament stem cells (PDLSCs) aggregate is still limited in clinical application for lack of angiogenesis. This study aimed to investigate the effects and underlying mechanism of exosomes derived from stem cells from human exfoliated deciduous teeth (SHED) aggregate (SA-Exo) on the aggregate formation and angiogenic properties of PDLSCs.Methods: SA-Exo were isolated by ultracentrifugation. The effect of SA-Exo on the aggregate formation and angiogenic differentiation of PDLSCs were evaluated by investigating extracellular matrix (ECM) deposition and tube formation assay. MicroRNA (miRNA) sequencing was employed to screen different miRNA expression. The effect of targeting miRNA on ECM deposition and angiogenesis of PDLSCs aggregate was investigated after overexpression and inhibition of miRNA. Periodontal bone defect rat models were established to evaluate the effect of the PDLSCs aggregate and SA-Exo combination on periodontal bone regeneration. Results: SA-Exo could significantly enhance the ECM deposition and angiogenic ability of PDLSCs. The expression of ECM-associated proteins (COL-I, integrinβ1, and fibronectin), angiogenesis-related proteins (PDGF, ANG, TGFβRII), and related pathway (p-SMAD1/5 and p-SMAD2/3) were upregulated in PDLSCs aggregate with SA-Exo. Mechanistically, miR-222 was found relatively abundant in SA-Exo, which promoted ECM deposition and angiogenesis of PDLSCs. In vivo experiment further validated that combinational use of PDLSCs aggregate and SA-Exo promote more bone formation and neovascularization in rat’s periodontal bone defect.Conclusions: SA-Exo-shuttled miR-222 contributes to PDLSCs aggregate engineering by promoting aggregate formation and angiogenesis, which might through activate the TGF-β/SMAD signaling pathway.


2019 ◽  
Vol 48 (4) ◽  
pp. 030006051985164
Author(s):  
Jun Li ◽  
Youjian Peng

Objective To investigate the effects of the flavonoid, puerarin, on osteogenic differentiation of human periodontal ligament stem cells (PDLSCs). Methods Human PDLSCs were isolated from patients undergoing orthodontic treatment, and the cell surface markers CD146, CD34, CD45, and STRO-1 were identified by immunofluorescence. Cell proliferation was detected by MTT assay; alkaline phosphatase (ALP) activity was measured, and calcium deposition was detected by alizarin red staining. PCR was then used to detect the distributions of COL-I, OPN, Runx2, and OCN, genes related to osteogenic differentiation. Results Staining was positive for cytokines CD146, CD34, CD45, and STRO-1 in the experimental group; staining was also positive for silk protein, but negative for keratin. After 7 days of culture, exposure to puerarin significantly promoted the level of intracellular ALP; increased puerarin concentration led to increased intracellular ALP. Red mineralized nodules appeared upon exposure to puerarin and the number of nodules was concentration-dependent. PCR analysis revealed that COL-I, OPN, Runx2, and OCN expression levels increased as puerarin concentration increased. Conclusions Exposure to puerarin can promote proliferation and ALP activity in human PDLSCs, thus promoting both molecular and osteogenic differentiation; these findings may provide a theoretical basis for the clinical treatment of periodontal disease with puerarin.


2020 ◽  
Author(s):  
Yi Zhao ◽  
Qiaoli Zhai ◽  
Hong Liu ◽  
Xun Xi ◽  
Shuai Chen ◽  
...  

Abstract BackgroundPeriodontal disease is a common disease that compromises the integrity of tooth-supporting tissues. Bone regeneration is the ultimate goal of periodontal therapies, in which osteogenic differentiation of human periodontal ligament stem cells plays a critical role. The tripartite motif (TRIM)16 is downregulated in periodontal tissues of patients with periodontitis and involved in osteogenic differentiation of human bone marrow mesenchymal stem cells(hBMSCs).However, the role of TRIM16 in the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) is largely unknown.MethodshPDLSCs were isolated and identified by immunophenotype assays using flow cytometry. Overexpression plasmids and specific short-hairpin RNAs (shRNAs) were constructed to manipulate the expression of target molecules. Alkaline phosphatase (ALP) staining, alizarin red staining (ARS) and enzyme‐linked immunosorbent assays (ELISA) were used to evaluate osteogenic potential capacity. Reverse transcription quantitative PCR (RT-qPCR) and Western blot analysis were performed to determine the expression of osteogenic-related markers and activation of relevant signaling pathways. Co-immunoprecipitation assays were performed to confirm the interactions between proteins and the ubiquitination of RUNX2. A LC-MS/MS analysis was performed to explore the different expression proteins in present of TRIM16.ResultsTRIM16 significantly promoted alkaline phosphatase activity and mineralized nodule formation, and positively regulated the osteogenic differentiation of hPDLSCs by enhancing protein expression of RUNX2, COL1A1 and OCN. Mechanistically, TRIM16 serves as a pivotal factor that stabilizes RUNX2 protein levels by decreasing CHIP-mediated K48-linked ubiquitination degradation of the RUNX2 protein. Besides, TRIM16 significantly increased expression of COL1A1 via activation of p38MAPK/RUNX2.ConclusionThis study identified a novel mechanism of TRIM16 in regulating stability of the RUNX2 protein, which may promote the osteogenic differentiation of hPDLSCs. TRIM16 may be a potential target of stem cell based-bone regeneration for periodontal therapies.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Lin Fu ◽  
Na Li ◽  
Yu Ye ◽  
Xiaying Ye ◽  
Tong Xiao ◽  
...  

Let-7 miRNA family has been proved as a key regulator of mesenchymal stem cells’ (MSCs’) biological features. However, whether let-7b could affect the differentiation or proliferation of periodontal ligament stem cells (PDLSCs) is still unknown. Here, we found that the expression of hsa-let-7b was visibly downregulated after mineralization induction of PDLSCs. After transfected with hsa-let-7b mimics or inhibitor reagent, the proliferation ability of PDLSCs was detected by cell counting kit-8 (CCK-8), flow cytometry, and 5-ethynyl-2-deoxyuridine (EdU) assay. On the other hand, the osteogenic differentiation capacity was detected by alkaline phosphatase (ALP) staining and activity, alizarin red staining, Western blot, and quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). We verified that hsa-let-7b did not significantly impact the proliferation ability of PDLSCs, but it could curb the osteogenic differentiation of PDLSCs. Besides, we predicted CTHRC1 acts as the downstream gene of hsa-let-7b to affect this process. Moreover, the combination of CTHRC1 and hsa-let-7b was verified by dual luciferase reporter assay. Our results demonstrated that the osteogenic differentiation of PDLSCs was enhanced after inhibiting hsa-let-7b, while was weakened after cotransfection with Si-CTHRC1. Collectively, hsa-let-7b can repress the osteogenic differentiation of PDLSCs by regulating CTHRC1.


2014 ◽  
Vol 23 (20) ◽  
pp. 2524-2534 ◽  
Author(s):  
Bei Li ◽  
Yu Zhang ◽  
Qingchao Wang ◽  
Zhiwei Dong ◽  
Linjuan Shang ◽  
...  

2020 ◽  
Author(s):  
Xiaoyu Li ◽  
Bowen Zhang ◽  
Hong Wang ◽  
Xiaolu Zhao ◽  
Zijie Zhang ◽  
...  

Abstract Background: Periodontal ligament stem cells (PDLSCs) have many applications in the field of cytotherapy, tissue engineering, and regenerative medicine. However, the effect of age on the biological characteristics and immunoregulation of PDLSCs remains unclear.Methods: In this study, we compared PDLSCs isolated from young and elderly individuals. PDLSCs proliferation was analyzed by Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) staining, and apoptosis level was detected by Annexin V-PE/7-ADD staining. PDLSCs osteogenic/adipogenic differentiation potentials were assessed by alkaline phosphatase (ALP), Alizarin Red, Oil Red O staining and related quantitative analysis. PDLSCs immunoregulatory capacity was determined by EdU and Annexin V-PE/7-ADD staining. To explore its underlying mechanism, microarray, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), and western blot analyses were performed to detect differentially expressed genes and proteins in PDLSCs. Results: Our results demonstrated that with aging, the proliferation and osteogenic/adipogenic differentiation potential of PDLSCs decreased, whereas apoptosis of PDLSCs increased. Moreover, the immunosuppressive ability of PDLSCs decreased with aging. Compared with PDLSCs from young subjects, analysis of mRNA expression revealed an upregulation of CCND3 and RC3H2 , and a downregulation of Runx2, ALP, COL1A1, PPARγ2, CXCL12, FKBP1A, FKBP1B, NCSTN, P2RX7, PPP3CB, RIPK2, SLC11A1, and TP53 in those from elderly individuals. Furthermore, protein expression levels of Runx2, ALP, COL1A1, and PPARγ2 in the elderly group was decreased, whereas that of CCND3 increased. Conclusions: Taken together, aging influences biological and immunological characteristics of PDLSCs, and thus it is more appropriate to utilized PDLSCs from young individuals for tissue regeneration, post-aging treatment, and allotransplantation.


2019 ◽  
Author(s):  
Zhuo Wang ◽  
Yuanliang Huang ◽  
Luanjun Tan

Abstract Backgrounds: Long non-coding RNAs (lncRNAs) have been widely known to have an appreciable effect in physiology and pathology. In tooth regeneration, periodontal ligament stem cells (PDLSCs) are regarded as a key effector, whereas, how lncRNA acts in the osteogenic differentiation of PDLSCs have not been completely understood. This study aims to find out the relationship between lncRNA DANCR and the proliferation and osteogenic differentiation of PDLSCs. Method: Microarray was used to observe the different expression of lncRNAs in differentiated and undifferentiated PDLSCs. And then osteogenic-related lncRNA, DNACR was screened out. To explore its effects on proliferation and osteogenic differentiation by constructing an overexpression and inhibition model. qRT-PCR was used to detect the mRNA expression of osteogenesis related genes. MTT assay was performed to assess the effects of DNACR on cell growth curve. To quantify the effects of DNACR on osteogenic differentiation of PDLCs, ALP staining and alizarin red was performed in basic culture medium and osteogenic medium. Data were statistically processed. Results: Compared with the undifferentiated PDLSCs, the alizarin red staining level was higher in differentiated PDLSCs. And the expressions of osteogenic differentiation marker genes Runt-related transcription factor 2 (Runx2), osteocalcin (OCN) and bone morphogenetic protein (BMP-2) were significantly increased in the differentiated PDLSCs. Furthermore, we noticed that comparing with control groups, the expression of LncRNA DANCR decreases markedly in osteogenically induced PDLSCs. DANCR promoted proliferation of PDLSCs, as evidenced by cell viability. Further investigation has proven that the downregulation of DANCR shows in the calcium sediment forming, alkaline phosphatase (ALP) activation and some osteogenic-related gene markers’ upregulation including Runx2, OCN and BMP-2, which finally results in the osteogenic differentiation of PDLSCs following the transfection and induction. Conversely, DANCR upregulation was shown to repress the osteogenic differentiation potential of PDLSCs. Conclusions: The osteogenic differentiation of PDLSCs has proven to related to the down regulation of lncRNA DANCR. And this paper throws light on the effects of DANCR in the process of PDLSCs’ osteogenic differentiation.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Yu Ye ◽  
Yue Ke ◽  
Liu Liu ◽  
Tong Xiao ◽  
Jinhua Yu

The ability of human periodontal ligament stem cells (PDLSCs) to differentiate into osteoblasts is significant in periodontal regeneration tissue engineering. In this study, we explored the role and mechanism of circRNA FAT1 (circFAT1) in the osteogenic differentiation of human PDLSCs. The proliferation capacity of PDLSCs was evaluated by EdU and CCK-8 assay. The abilities of circFAT1 and miR-4781-3p in regulating PDLSC differentiation were analyzed by western blot, reverse transcription-polymerase chain reaction (RT-PCR), alkaline phosphatase (ALP), and Alizarin red staining (ARS). A nucleocytoplasmic separation experiment was utilized for circFAT1 localization. A dual-luciferase reporter assay confirmed the binding relationship between miR-4781-3p and circFAT1. It was showed that circFAT1 does not affect the proliferation of PDLSCs. The osteogenic differentiation of PDLSCs was benefited from circFAT1, which serves as a miRNA sponge for miR-4781-3p targeting SMAD5. Both knockdown of circFAT1 and overexpression of miR-4781-3p suppressed the osteogenic differentiation of PDLSCs. Thus, circFAT1 might be considered as a potential target of PDLSCs mediated periodontal bone regeneration.


Sign in / Sign up

Export Citation Format

Share Document