EZH2 Regulates Lipopolysaccharide-Induced Periodontal Ligament Stem Cell Proliferation and Osteogenesis through TLR4/MyD88/NF-κB Pathway

Background. Periodontitis induced by bacteria especially Gram-negative bacteria is the most prevalent chronic inflammatory disease worldwide. Emerging evidence supported that EZH2 plays a significant role in the inflammatory response of periodontal tissues. However, little information is available regarding the underlying mechanism of EZH2 in periodontitis. This study is aimed at determining the potential role and underlying mechanism of EZH2 in periodontitis. Methods. The protein levels of EZH2, H3K27ME, p-p65, p-IKB, TLR4, MyD88, Runx2, and OCN were examined by western blot assay. Proliferation was evaluated by CCK8 assay. The levels of TNFα, IL1β, and IL6 were detected by ELISA assay. Migration was detected by wound healing assay. The distribution of p65 was detected by immunofluorescence. The formation of mineralized nodules was analyzed using alizarin red staining. Results. LPS stimulation significantly promoted EZH2 and H3K27me3 expression in primary human periodontal ligament stem cells (PDLSCs). Targeting EZH2 prevented LPS-induced upregulation of the inflammatory cytokines and inhibition of cell proliferation and migration. Furthermore, EZH2 knockdown attenuated the TLR4/MyD88/NF-κB signaling to facilitate PDLSC osteogenesis. Conclusions. Modulation of the NF-κB pathway through the inhibition of EZH2 may offer a new perspective on the treatment of chronic apical periodontitis.

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Epigenetic silencing of KLF2 by long non-coding RNA SNHG1 inhibits periodontal ligament stem cell osteogenesis differentiation

Stem Cell Research & Therapy ◽

10.1186/s13287-020-01953-8 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Zhaobao Li ◽

Xiangjun Guo ◽

Shuainan Wu

Keyword(s):

Osteogenic Differentiation ◽

Periodontal Ligament ◽

Marker Genes ◽

Loss Of Function ◽

Periodontal Ligament Stem Cells ◽

Alizarin Red ◽

Protein Levels ◽

Dental Tissues ◽

Periodontal Ligament Stem Cell ◽

Novel Therapeutic Strategies

Abstract Background Exploring the effects of lncRNA SNHG1 in the process of osteogenic differentiation of periodontal ligament stem cells (PDLSCs) would provide novel therapeutic strategies for tissue regeneration. Methods Loss-of-function and gain-of-function assays were induced by lentivirus. The osteogenic differentiation of PDLSCs were assessed by ALP staining and Alizarin Red staining as well as the mRNA and protein levels of osteogenic marker genes osterix, osteocalcin, and alkaline phosphatase through qRT-PCR and western blot. RNA immunoprecipitation assay and chromatin immunoprecipitation assays were performed to uncover the interaction between SNHG1 and EZH2. Results Our analysis revealed that SNHG1 was downregulated and KLF2 was upregulated during the osteogenic induction differentiation of PDLSCs. SNHG1 inhibited while KLF2 promoted osteogenic differentiation of PDLSCs. SNHG1 directly interact with the histone methyltransferase enhancer of the zeste homolog 2 (EZH2) and modulate the histone methylation of promoter of Kruppel-like factor 2 (KLF2) and altered the progress osteogenic differentiation of PDLSCs. Conclusions Taken together, SNHG1 inhibited the osteogenic differentiation of PDLSCs through EZH2-mediated H3K27me3 methylation of KLF2 promotor and provided a novel class of therapeutic targets for regenerate dental tissues.

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Red and Yellow Injectable Platelet-Rich Fibrin Demonstrated Differential Effects on Periodontal Ligament Stem Cell Proliferation, Migration, and Osteogenic Differentiation

International Journal of Molecular Sciences ◽

10.3390/ijms21145153 ◽

2020 ◽

Vol 21 (14) ◽

pp. 5153 ◽

Cited By ~ 1

Author(s):

Prakan Thanasrisuebwong ◽

Sirichai Kiattavorncharoen ◽

Rudee Surarit ◽

Chareerut Phruksaniyom ◽

Nisarat Ruangsawasdi

Keyword(s):

Cell Proliferation ◽

Cell Migration ◽

Bone Regeneration ◽

Osteogenic Differentiation ◽

Periodontal Ligament ◽

Buffy Coat ◽

Periodontal Ligament Stem Cells ◽

Alizarin Red ◽

Platelet Rich Fibrin ◽

Periodontal Ligament Stem Cell

The biological benefits of using two fractions derived from injectable platelet-rich fibrin (i-PRF) in bone regeneration remain unclear. Thus, the current study examined two fractionation protocols producing yellow i-PRF and red i-PRF on periodontal ligament stem cells (PDLSCs). The i-PRF samples from five donors were harvested from two different levels, with and without a buffy coat layer, to obtain red and yellow i-PRF, respectively. The PDLSCs were isolated and characterized before their experimental use. The culture medium in each assay was loaded with 20% of the conditioned medium containing the factors released from the red and yellow i-PRF. Cell proliferation and cell migration were determined with an MTT and trans-well assay, respectively. Osteogenic differentiation was investigated using alkaline phosphatase and Alizarin red staining. The efficiency of both i-PRFs was statistically compared. We found that the factors released from the red i-PRF had a greater effect on cell proliferation and cell migration. Moreover, the factors released from the yellow i-PRF stimulated PDLSC osteogenic differentiation earlier compared with the red i-PRF. These data suggest that the red i-PRF might be suitable for using in bone regeneration because it induced the mobilization and growth of bone regenerative cells without inducing premature mineralization.

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TRIM16 Positively Regulates Osteogenic Differentiation of Human Periodontal Ligament Stem Cells by Modulating the Ubiquitination and Degradation of RUNX2

10.21203/rs.3.rs-38207/v1 ◽

2020 ◽

Author(s):

Yi Zhao ◽

Qiaoli Zhai ◽

Hong Liu ◽

Xun Xi ◽

Shuai Chen ◽

...

Keyword(s):

Stem Cells ◽

Alkaline Phosphatase ◽

Bone Regeneration ◽

Osteogenic Differentiation ◽

Periodontal Ligament ◽

Osteogenic Potential ◽

Common Disease ◽

Periodontal Ligament Stem Cells ◽

Alizarin Red ◽

Periodontal Tissues

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.

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TRIM16 Promotes Osteogenic Differentiation of Human Periodontal Ligament Stem Cells by Modulating CHIP-Mediated Degradation of RUNX2

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2020.625105 ◽

2021 ◽

Vol 8 ◽

Author(s):

Yi Zhao ◽

Qiaoli Zhai ◽

Hong Liu ◽

Xun Xi ◽

Shuai Chen ◽

...

Keyword(s):

Stem Cells ◽

Bone Regeneration ◽

Osteogenic Differentiation ◽

Periodontal Ligament ◽

Critical Role ◽

Nodule Formation ◽

Periodontal Ligament Stem Cells ◽

Protein Levels ◽

Periodontal Tissues ◽

Short Hairpin Rnas

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, an E3 ubiquitin ligase, is downregulated in periodontal tissues of patients with periodontitis, while the role of TRIM16 in the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) is largely unknown. Firstly, we found that TRIM16 was increased throughout the osteogenic media induced differentiation of hPDLSCs. Then overexpression plasmids and specific short-hairpin RNAs (shRNAs) were constructed to manipulate the expression of target molecules. TRIM16 significantly promoted alkaline phosphatase activity, mineralized nodule formation, and positively regulated the expression of osteo-specific markers RUNX2, COL1A1 and OCN except the mRNA of RUNX2. Mechanistically, TRIM16 serves as a pivotal factor that stabilizes RUNX2 protein levels by decreasing CHIP-mediated K48-linked ubiquitination degradation of the RUNX2 protein. This study identified a novel mechanism of TRIM16 in regulating stability of the RUNX2 protein, which promoted the osteogenic differentiation of hPDLSCs. TRIM16 may be a potential target of stem cell based-bone regeneration for periodontal therapies.

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Melatonin Promotes Osteogenic Differentiation in Lipopolysaccharide-Stimulated Human Periodontal Ligament Stem Cells Through Bone Morphogenic Proteins-2-Related Signaling

Journal of Biomaterials and Tissue Engineering ◽

10.1166/jbt.2019.2032 ◽

2019 ◽

Vol 9 (5) ◽

pp. 679-686

Author(s):

Na Yu ◽

Jinghui Zhang ◽

Lijuan Han ◽

Cunjirigala Na ◽

Xiaoguang Yuan

Keyword(s):

Stem Cells ◽

Cell Proliferation ◽

Wnt Signaling ◽

Osteogenic Differentiation ◽

Periodontal Ligament ◽

Biological Activities ◽

Phase Cell ◽

Periodontal Ligament Stem Cells ◽

Alizarin Red ◽

Protein Expressions

Periodontitis is one of the most widespread infectious diseases that troubled the majority of adults. Human periodontal ligament stem cells (hPDLSCs) have been reported as a promising therapy for the treatment of periodontitis. Melatonin, an indoleamine hormone from pineal gland, has various biological activities such as anti-inflammation, anti-cancer and so on. However, whether it is functional in periodontitis is still unclear. The aim of this study was to investigate the effect of melatonin in periodontitis and elucidate the molecular mechanism. Lipopolysaccharide (LPS) was used to stimulate hPDLSCs, and viability of hPDLSCs that was treated with melatonin (0, 1, 10, 50 and 100 μmol/L) for 24 h or 48 h was determined by MTT assay. Flow cytometry analysis was carried out to detect the influence of melatonin on cell proliferation. Osteogenic differentiation ability of melatonin was determined by Alkaline phosphatase (ALP) assay kit and Alizarin Red Staining. Lastly, western blot was used for the determination of protein expressions related to proliferation, differentiation and ERK/Wnt signaling activity. The results showed that LPS significantly inhibited cell viability, which was reversed by melatonin, especially at 10 μM for 48 h and at 50 μM for 24 h. Melatonin (10 μM, 48 h) and melatonin (50 μM, 24 h) notably induced G0/G1 phase cell arrest, increased the expression of CDK2, cyclin E and decreased the expression of p27 in LPS-stimulated hPDLSCs. Besides, melatonin significantly promoted cell differentiation through increasing ALP activity, mineralization and protein expressions of Oct4, Sox-2, Runx2 and bone morphogenic protein-2 (BMP-2). Additionally, BMP-2 related ERK and Wnt signaling was activated with the treatment of melatonin in LPS-stimulated hPDLSCs. Collectively, melatonin could improve cell proliferation and osteogenic differentiation in LPS-stimulated hPDLSCs, partly through regulating BMP2-related ERK/Wnt pathway.

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Attenuation of Porphyromonas Gingival Lipopolysaccharide-Induced Periodontal Ligament Stem Cells Injury and Inflammation by Blocking Cell Pyroptosis

Journal of Biomaterials and Tissue Engineering ◽

10.1166/jbt.2021.2759 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1940-1946

Author(s):

Shuangfeng Jiang ◽

Shanjuan Huang ◽

Jin Liu ◽

Qi Zhou ◽

Xiaosheng Liu

Keyword(s):

Stem Cells ◽

Cell Proliferation ◽

Osteogenic Differentiation ◽

Inflammatory Cytokines ◽

Chronic Periodontitis ◽

Cell Apoptosis ◽

Periodontal Ligament ◽

High Mobility ◽

Periodontal Ligament Stem Cells ◽

Alizarin Red

Periodontitis is a chronic inflammation of periodontal tissue, and programmed cell death plays an important role in chronic periodontitis induced by P. gingivalis. Studies have shown that the increased expression of pyroptosis-related NLRP3 inflammasome and the pro-inflammatory cytokines IL-1β and IL-18 in gingivitis, invasive periodontitis, and chronic periodontitis patients. The present study aimed to investigate whether the inhibition of pyroptosis could protect porphyromonas gingival lipopolysaccharide (pg-LPS)-induced human periodontal ligament stem cells (hPDLSCs) injury and inflammation. The hPDLSCs were treated with pg-LPS and ATP in the presence of caspase1/4 inhibitor VX765. The cell proliferation and survival were assessed by CCK-8, the osteogenic differentiation capacity was evaluated by Alkaline Phosphatase (ALP) assay and alizarin red staining. Then, cell apoptosis, cleavage of gasdermin D (GSDMD) and generation of inflammatory cytokines were estimated. Lastly, western blotting was used to detect the expression of potential target proteins. Results showed that the treatment of pg-LPS plus ATP significantly inhibited the proliferation, survival and osteogenic differentiation of hPDLSCs, while inducing cell apoptosis, pyroptosis and inflammation. However, the presence of VX765 partially recovered the cell proliferation, survival and osteogenic differentiation. At the same time, VX765 inhibited cell apoptosis, cleavage of GSDMD and generation of inflammatory cytokines. Besides, the expression of related proteins including Bax, Bcl-2, cleaved (c)-caspase3, c-caspase4, c-caspase1, Toll Like Receptor 4, High Mobility Group Box 1 (HMGB1) and NLRP3 was all rescued by VX765. In conclusion, our results revealed that the blocking of cell pyroptosis could protect hPDLSCs from pg-LPS-induced injury. Therefore, the application of pyroptosis inhibitor may be a valuable therapeutic approach for treating periodontitis.

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D-Mannose Enhanced Immunomodulation of Periodontal Ligament Stem Cells via Inhibiting IL-6 Secretion

Stem Cells International ◽

10.1155/2018/7168231 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Lijia Guo ◽

Yanan Hou ◽

Liang Song ◽

Siying Zhu ◽

Feiran Lin ◽

...

Keyword(s):

T Cell ◽

Periodontal Ligament ◽

Alveolar Bone ◽

Periodontal Regeneration ◽

Treg Cells ◽

Cell Number ◽

Periodontal Ligament Stem Cells ◽

Periodontal Tissues ◽

Periodontal Tissue Regeneration ◽

Periodontal Ligament Stem Cell

Periodontal ligament stem cell- (PDLSC-) mediated periodontal tissue regeneration has recently been proposed for the new therapeutic method to regenerate lost alveolar bone and periodontal ligament. It was reported that both autogenic and allogeneic PDLSCs could reconstruct damaged periodontal tissues but the regeneration effects were not consistent. The effective methods to improve the properties of PDLSCs should be further considered. In this study, we investigated if D-mannose could affect the immunomodulatory properties of hPDLSCs. After being pretreated with D-mannose, hPDLSCs could inhibit T cell proliferation and affect T cell differentiation into Treg cells. We found that less IL-6 could be detected in D-mannose-pretreated hPDLSCs. In the D-mannose pretreatment group, induced Treg cell number would decrease if increased IL-6 levels could be detected. Our data uncovered a previously unrecognized function of D-mannose to regulate the immunomodulatory function of PDLSCs and that IL-6 might play a key role in this process. The results provided a property method to improve PDLSC-based periodontal regeneration.

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Targeting EZH2 Ameliorates the LPS-Inhibited PDLSC Osteogenesis via Wnt/β-Catenin Pathway

Cells Tissues Organs ◽

10.1159/000511702 ◽

2021 ◽

pp. 1-9

Author(s):

Mosha Cheng ◽

Qing Zhou

Keyword(s):

Bone Morphogenetic Protein 2 ◽

Periodontal Ligament Stem Cells ◽

Alizarin Red ◽

Protein Levels ◽

Inflammatory Conditions ◽

Morphogenetic Protein ◽

Related Transcription Factor ◽

Underlying Mechanisms ◽

Factor Α ◽

Osteoblast Maturation

As a histone methyltransferase, enhancer of zeste homolog 2 (EZH2), suppresses osteoblast maturation and is involved in inflammation. However, the role of EZH2 in human periodontal ligament stem cells (PDLSCs) under inflammation still needs to be further investigated. This study aimed to identify the underlying mechanisms and explore the function of EZH2 in PDLSC osteogenesis under inflammation. PDLSCs were treated with sh-EZH2, DZNep or DKK1 under inflammation. The alkaline phosphatase (ALP) activity, alizarin red staining, and osteogenesis-related protein levels were analyzed. Lipopolysaccharide (LPS)-induced inflammation restrained osteogenic differentiation. Under inflammation, the upregulation of EZH2 suppressed the expression of osteogenic markers, including osteocalcin, runt-related transcription factor 2, and bone morphogenetic protein-2, the activity of ALP, and the accumulation of mineralization through the Wnt/β-catenin pathway. EZH2 knockdown inhibited the levels of proinflammatory cytokines such as interleukin-6 and tumor necrosis factor-α. These results suggested that LPS-induced overexpression of EZH2 suppressed PDLSC osteogenesis under inflammatory conditions through the Wnt/β-catenin pathway. These findings give new insights into the physiological differentiation and pathological inflammation of PDLSC osteogenesis, and provide an underlying therapeutic target for periodontitis.

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Azithromycin Promotes the Osteogenic Differentiation of Human Periodontal Ligament Stem Cells after Stimulation with TNF-α

Stem Cells International ◽

10.1155/2018/7961962 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Tingting Meng ◽

Ying Zhou ◽

Jingkun Li ◽

Meilin Hu ◽

Xiaomeng Li ◽

...

Keyword(s):

Stem Cells ◽

Alkaline Phosphatase ◽

Osteogenic Differentiation ◽

Alkaline Phosphatase Activity ◽

Periodontal Ligament ◽

Caspase 3 ◽

Caspase 8 ◽

Periodontal Ligament Stem Cells ◽

Alizarin Red ◽

Induced Apoptosis

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.

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SHED Aggregate Derived Exosomes-shuttled miR-222 Promotes the Regenerative Properties of Periodontal Ligament Stem Cells

10.21203/rs.3.rs-432229/v1 ◽

2021 ◽

Author(s):

Feng Zhou ◽

Jia Guo ◽

Fang Wang ◽

Wanmin Zhao ◽

Xiaoning He ◽

...

Keyword(s):

Stem Cells ◽

Bone Defect ◽

Periodontal Ligament ◽

Underlying Mechanism ◽

Tube Formation ◽

Deciduous Teeth ◽

Aggregate Formation ◽

Periodontal Ligament Stem Cells ◽

Mirna Sequencing

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.

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