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ABSTRACT Periodontal ligament stem cells (PDLSCs) are key cells that suppress periodontal damage during both the progression and recovery stages of periodontitis. Although substantial evidence has demonstrated that incubation under an inflammatory condition may accelerate senescence of PDLSCs, whether cellular senescence in response to inflammatory incubation contributes to cell dysfunction remain unexplored. In this study, we first observed inflammation‐caused PDLSC senescence in periodontitis based on comparisons of matched patients, and this cellular senescence was demonstrated in healthy cells that were subjected to inflammatory conditions. We subsequently designed further experiments to investigate the possible mechanism underlying inflammation‐induced PDLSC senescence with a particular focus on the role of long noncoding RNAs (lncRNAs). LncRNA microarray analysis and functional gain/loss studies revealed SLC30A4‐AS1 as a regulator of inflammation‐mediated PDLSC senescence. By full‐length transcriptome sequencing, we found that SLC30A4‐AS1 interacted with SRSF3 to affect the alternative splicing (AS) of TP53BP1 and alter the expression of TP53BP1‐204. Further functional studies showed that decreased expression of TP53BP1‐204 reversed PDLSC senescence, and SLC30A4‐AS1 overexpression‐induced PDLSC senescence was abolished by TP53BP1‐204 knockdown. Our data suggest for the first time that SLC30A4‐AS1 plays a key role in regulating PDLSC senescence in inflammatory environments by modulating the AS of TP53BP1. [ABSTRACT FROM AUTHOR]

Periodontal ligament stem cells (PDLSCs) have broad applications in tissue engineering and regeneration. However, the function of PDLSCs changes in different microenvironments. This study aimed to explore the effects of different developmental stages on the biological characteristics of PDLSCs. Here, PDLSCs were successfully cultured from the periodontal tissues of various groups, including a group with immature roots, a young group with mature roots, and an aging group with mature roots. By comparing the results of the three experimental groups, we found that the donors with immature roots exhibited the best proliferative ability and osteogenic differentiation, whereas the aging group demonstrated the worst proliferation. The trend for adipogenic differentiation was the opposite to that for osteogenic differentiation. The cell sheet and in vivo experiments revealed that in the immature root group, the cells produced more extracellular matrix and new bone and better absorbed the implant materials. These results indicate that PDLSCs perform various functions at different stages of development. In clinical applications of PDLSCs for periodontal regeneration, donors with incompletely developed roots have stronger biological characteristics. [ABSTRACT FROM AUTHOR]

Approximately half of the adult population is suffering from periodontal disease, and conventional periodontal treatment strategies can only slow the progression of the disease. As a kind of tissue engineering, periodontal regeneration brings hope for the treatment of periodontal disease. Low-intensity pulsed ultrasound (LIPUS) is a form of ultrasound with a frequency of 1–3 MHz and a much lower intensity (< 1W/cm2) than traditional ultrasound energy and output. LIPUS has been adopted for a variety of therapeutic purposes due to its bioeffects such as thermal, mechanical, and cavitation effects, which induce intracellular biochemical effects and lead to tissue repair and regeneration ultimately. In this systematic review, we summarize the basic research of LIPUS in the treatment of periodontal disease in periodontal disease animal models and the influence of LIPUS on the biological behavior (including promoting osteogenic differentiation of stem cells and inhibiting inflammatory response) and potential mechanism of periodontal ligament stem cells (PDLSCs), hoping to provide new ideas for the treatment of periodontal disease. We believe that LIPUS can be used as an auxiliary strategy in the treatment of periodontal disease and play an exciting and positive role in periodontal regeneration. [ABSTRACT FROM AUTHOR]

Background: The immunogenicity of allogeneic mesenchymal stem cells (MSCs) is significantly enhanced after transplantation or differentiation, and these cells can be recognized and cleared by recipient immune cells. Graft rejection has become a major obstacle to improving the therapeutic effect of allogeneic MSCs or, after their differentiation, transplantation in the treatment of diabetes and other diseases. Solving this problem is helpful for prolonging the time that cells play a role in the recipient body and for significantly improving the clinical therapeutic effect. Methods: In this study, canine adipose-derived mesenchymal stem cells (ADSCs) were used as seed cells, and gene editing technology was used to knock out the B2M gene in these cells and cooperate with the overexpression of the PD-L1 gene. Gene-edited ADSCs (GeADSCs), whose biological characteristics and safety are not different from those of normal canine ADSCs, have been obtained. Results: The immunogenicity of GeADSCs is reduced, the immune escape ability of GeADSCs is enhanced, and GeADSCs can remain in the body for a longer time. Using the optimized induction program, the efficiency of the differentiation of GeADSCs into new islet ß-cells was increased, and the maturity of the new islet ß-cells was increased. The immunogenicity of new islet ß-cells decreased, and their immune escape ability was enhanced after the cells were transplanted into diabetic dogs (the graft site was prevascularized by the implantation of a scaffold to form a vascularized pouch). The number of infiltrating immune cells and the content of immune factors were decreased at the graft site. Conclusions: New islet ß-cell transplantation, which has low immunogenicity, can reverse diabetes in dogs, and the therapeutic effect of cell transplantation is significantly enhanced. This study provides a new method for prolonging the survival and functional time of cells in transplant recipients and significantly improving the clinical therapeutic effect. [ABSTRACT FROM AUTHOR]

Objective As a signaling molecule, NO regulates key physiological processes and is closely related to periodontitis. To investigate the effect of flavonoid NO donor composite nanoparticles (G10@HAP/MSN@ZnO@COS) on osteogenic differentiation of periodontal ligament stem cells (PDLSCs) by regulating macrophage polarization. Methods The novel NO donor drug G10 was loaded on hydroxyapatite/mesoporous silicanant particles (HAP/MSN), filled with zinc oxide (ZnO), and then coated with chitosan (COS) to prepare composite nanoparticles (G10@HAP/MSN@ZnO@COS). The best concentration of G10@HAP/MSN@ZnO@COS was screened to promote cell proliferation by CCK-8 cell experiment. After the mouse mononuclear macrophages were stimulated by lipopolysaccharide, the mice were divided into four groups: Control group, G10 group, HAP/MSN@ZnO@COS group and G10@HAP/MSN@ZnO@COS group. Each group was cultured with fresh medium, 5 μg/mL G10, 5 μg/ mL HAP/MSN@ZnO@COS and 5 μg/mL G10@HAP/MSN@ZnO@COS for 72 h respectively. ELISA and RT-qPCR were used to detect the expression of cytokines (TNF-α, IL-6, IL-1β, iNOS, IL-10) and mRNA expression in each group, and the phenotypic changes of M1/M2 were evaluated. The supernatant of each culture medium was used as conditioned medium to culture PDLSCs, and the osteogenic ability and cell mineralization were evaluated by alkaline phosphatase activity test and alizarin red staining. Results CCK-8 experiment showed that G10@HAP/MSN@ZnO@COS of 5 μg/mL could significantly promote the proliferation of PDLSCs. The results of ELISA showed that compared with Control group, the expression of M1 type marker IL-1β, IL-6, TNF-α and iNOS in G10@HAP/MSN@ZnO@COS group was significantly decreased (P

Shuai Tang,1– 4 Wenyu Feng,2– 4 Zekun Li,1 Xinjuan Liu,1 Tong Yang,1– 4 Fulan Wei,2– 4 Gang Ding1 1School of Stomatology, Shandong Second Medical University, Weifang, Shandong, 261053, People’s Republic of China; 2Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, People’s Republic of China; 3Shandong Key Laboratory of Oral Tissue Regeneration, Shandong University, Jinan, Shandong, 250012, People’s Republic of China; 4Shandong Provincial Clinical Research Center for Oral Diseases, Shandong University, Jinan, Shandong, 250012, People’s Republic of ChinaCorrespondence: Gang Ding, School of Stomatology, Shandong Second Medical University, Baotong West Street No. 7166, Weifang, Shandong, 261053, People’s Republic of China, Email dinggang@sdsmu.edu.cn Fulan Wei, Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University, Wenhua West Road No. 44-1, Jinan, Shandong, 250012, People’s Republic of China, Email weifl@sdu.edu.cnIntroduction: Inflammatory bowel disease is a complex chronic inflammatory condition characterized by dysbiosis of the gut microbiota and dysregulation of immune system. In recent years, extracellular vesicles (EVs) derived from mesenchymal stem cells have garnered significant attention for their beneficial potentials in immune modulation and tissue repair. This study aims to evaluate the therapeutic effects and underlying mechanisms of EVs derived from lipopolysaccharide (LPS)-pretreated periodontal ligament stem cells (PDLSCs) in mice with colitis.Methods: A mouse model of colitis was established using 3.0% dextran sulfate sodium (DSS). Following the induction of colitis, mice were treated via tail vein injection with either conventional PDLSC-derived EVs (P-EVs) or LPS-pretreated PDLSC-derived EVs (LPS pre-EVs). The EVs were characterized using transmission electron microscopy, nanoparticle tracking analysis, and Western blot analysis. The therapeutic effects and mechanisms were evaluated through a combination of small animal live imaging, disease activity index (DAI) scoring, histopathological staining, qRT-PCR, 16S rRNA gene sequencing, and mass spectrometry analysis.Results: The LPS pre-EVs exhibited typical EVs characteristics in terms of morphology, particle size distribution, and marker protein expression. Compared to P-EVs, LPS pre-EVs significantly ameliorated weight loss, DAI scores, colon length, and perianal symptoms in DSS-induced murine colitis. Additionally, LPS pre-EVs up-regulated the expression of Arginase-1, a typical M2 macrophage marker, and tight junction proteins, including ZO-1, Occludin, and Claudin-1, enhanced gut microbial diversity, and significantly regulated intestinal protein expression and activation of the PI3K/AKT signaling pathway.Conclusion: LPS pre-EVs exhibit significant anti-inflammatory and tissue repair effects in a mouse model of colitis. The underlying mechanisms may involve the regulation of macrophage polarization, maintenance of intestinal barrier function, modulation of the gut microbiota, and activation of the PI3K/AKT signaling pathway. Keywords: inflammatory bowel disease, periodontal ligament stem cells, extracellular vesicles, gut microbiota, PI3K/AKT signaling pathway

Introduction: Orthodontic tooth movement (OTM) involves complex interactions between mechanical forces and periodontal tissue adaptation, mainly mediated by periodontal ligament cells, including periodontal ligament stem cells (PDLSCs), osteoblasts, and osteoclasts. Dopamine (DA), a neurotransmitter known for its critical role in bone metabolism, is investigated in this study for its potential to enhance osteogenic differentiation in PDLSCs, which are pivotal in OTM. This study examined the potential of DA to facilitate OTM by binding to DA receptors (D1R and D2R) and activating the ERK1/2 signaling pathway. We propose that DA's interaction with these receptors on PDLSCs could enhance osteogenic differentiation, thereby accelerating bone remodeling and reducing the duration of orthodontic treatments, which offering a novel approach to improve clinical outcomes in orthodontic care. Methods: This study utilized a rat OTM model, micro-CT, histological analyses, and in vitro assays to investigate dopamine's effect on osteogenesis. PDLSCs were cultured and treated with DA, and cytotoxicity, osteogenic differentiation, gene and protein expression assessed. Results: Dopamine administration significantly increased trabecular bone density and osteogenic marker expression in an OTM rat model. In vitro, DA at 10 nM optimally promoted human PDLSCs osteogenesis without affecting proliferation. Blocking DA receptors or inhibiting the ERK1/2 pathway attenuated these effects, underscoring the importance of dopaminergic signaling in tension-induced osteogenesis during OTM. Conclusion: Taken together, our study reveals that local dopamine administration at a concentration of 10 nM not only enhances tension-induced osteogenesis in vivo but also significantly promotes osteogenic differentiation of PDLSCs in vitro through D1 and D2 receptor-mediated ERK1/2 signaling pathway activation.

Mesenchymal stem cells (MSCs) are highly favored in clinical trials due to their unique characteristics, which have isolated from various human tissues. Derived from dental tissues, dental stem cells (DSCs) are particularly notable for their applications in tissue repair and regenerative medicine, attributed to their readily available sources, absence of ethical controversies, and minimal immunogenicity. Hydrogel-loaded stem cell therapy is widespread across a variety of injuries and diseases, and has good repair capabilities for both soft and hard tissues. This review comprehensively summarizes the regenerative and differentiation potential of various DSCs encapsulated in hydrogels across different tissues. In addition, the existing problems and future direction are also addressed. The application of hydrogel–DSCs composite has gained substantial progress in the field of tissue regeneration and need in-depth study in the future. [ABSTRACT FROM AUTHOR]

Qingru Niu,1– 3,&ast; Chuanmiao Lin,1– 3,&ast; Shuqing Yang,1– 3 Shuxuan Rong,1– 3 Junbin Wei,1– 3 Tingting Zhao,1– 3 Yingying Peng,1– 3 Zhilan Cheng,1– 3 Yunyi Xie,1– 3 Yan Wang1– 3 1Hospital of Stomatology, Guanghua School of Stomatology, Guangzhou, People’s Republic of China; 2Sun Yat-Sen University, Guangzhou, People’s Republic of China; 3Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Yunyi Xie; Yan Wang, Email xieyy59@mail2.sysu.edu.cn; wang93@mail.sysu.edu.cnPurpose: Periodontitis is a chronic infectious disease characterized by progressive inflammation and alveolar bone loss. Forkhead box O1 (FoxO1), an important regulator, plays a crucial role in maintaining bone homeostasis and regulating macrophage energy metabolism and osteogenic differentiation of mesenchymal stem cells (MSCs). In this study, FoxO1 was overexpressed into small extracellular vesicles (sEV) using engineering technology, and effects of FoxO1-overexpressed sEV on periodontal tissue regeneration as well as the underlying mechanisms were investigated.Methods: Human periodontal ligament stem cell (hPDLSCs)-derived sEV (hPDLSCs-sEV) were isolated using ultracentrifugation. They were then characterized using transmission electron microscopy, Nanosight, and Western blotting analyses. hPDLSCs were treated with hPDLSCs-sEV in vitro after stimulation with lipopolysaccharide, and osteogenesis was evaluated. The effect of hPDLSCs-sEV on the polarization phenotype of THP-1 macrophages was also evaluated. In addition, we measured the reactive oxygen species (ROS) levels, adenosine triphosphate (ATP) production, mitochondrial characteristics, and metabolism of hPDLSCs and THP-1 cells. Experimental periodontitis was established in vivo in mice. HPDLSCs-sEV or phosphate-buffered saline (PBS) were injected into periodontal tissues for four weeks, and the maxillae were collected and assessed by micro-computed tomography, histological staining, and small animal in vivo imaging.Results: In vitro, FoxO1-overexpressed sEV promoted osteogenic differentiation of hPDLSCs in the inflammatory environment and polarized THP-1 cells from the M1 phenotype to the M2 phenotype. Furthermore, FoxO1-overexpressed sEV regulated the ROS level, ATP production, mitochondrial characteristics, and metabolism of hPDLSCs and THP-1 cells in the inflammatory environment. In the in vivo analyses, FoxO1-overexpressed sEV effectively promoted bone formation and inhibited inflammation.Conclusion: FoxO1-overexpressed sEV can regulate osteogenesis and immunomodulation. The ability of FoxO1-overexpressed sEV to regulate inflammation and osteogenesis can pave the way for the establishment of a therapeutic approach for periodontitis. Keywords: periodontal ligament stem cells, small extracellular vesicles, periodontitis, bone homeostasis, mitochondrial function

Abstract Background The role of periodontal ligament stem cells (PDLSCs) in repairing periodontal destruction is crucial, but their functions can be impaired by excessive oxidative stress (OS). Nocardamine (NOCA), a cyclic siderophore, has been shown to possess anti-cancer and anti-bacterial properties. This study aimed to investigate the protective mechanisms of NOCA against OS-induced cellular dysfunction in PDLSCs. Methods The cytotoxicity of NOCA on PDLSCs was assessed using a CCK-8 assay. PDLSCs were then treated with hydrogen peroxide (H2O2) to induce OS. ROS levels, cell viability, and antioxidant factor expression were analyzed using relevant kits after treatment. Small molecule inhibitors U0126 and XAV-939 were employed to block ERK signaling and Wnt pathways respectively. Osteogenic differentiation was assessed using alkaline phosphatase (ALP) activity staining and Alizarin Red S (ARS) staining of mineralized nodules. Expression levels of osteogenic gene markers and ERK pathway were determined via real-time quantitative polymerase chain reaction (RT-qPCR) or western blot (WB) analysis. β-catenin nuclear localization was examined by western blotting and confocal microscopy. Results NOCA exhibited no significant cytotoxicity at concentrations below 20 µM and effectively inhibited H2O2-induced OS in PDLSCs. NOCA also restored ALP activity, mineralized nodule formation, and the expression of osteogenic markers in H2O2-stimulated PDLSCs. Mechanistically, NOCA increased p-ERK level and promoted β-catenin translocation into the nucleus; however, blocking ERK pathway disrupted the osteogenic protection provided by NOCA and impaired its ability to induce β-catenin nuclear translocation under OS conditions in PDLSCs. Conclusions NOCA protected PDLSCs against H2O2-induced OS and effectively restored impaired osteogenic differentiation in PDLSCs by modulating the ERK/Wnt signaling pathway.

A thorough comprehension of age‐related variances in orthodontic tooth movement (OTM) and bone remodeling response to mechanical force holds significant implications for enhancing orthodontic treatment. Mitophagy plays a crucial role in bone metabolism and various age‐related diseases. However, the impact of mitophagy on the bone remodeling process during OTM remains elusive. Using adolescent (6 weeks old) and adult (12 months old) rats, we established OTM models and observed that orthodontic force increased the expression of the mitophagy proteins PTEN‐induced putative kinase 1 (PINK1) and Parkin, as well as the number of tartrate‐resistant acid phosphatase‐positive osteoclasts and osteocalcin‐positive osteoblasts. These biological changes were found to be age‐related. In vitro, compression force loading promoted PINK1/Parkin‐dependent mitophagy in periodontal ligament stem cells (PDLSCs) derived from adolescents (12–16 years old) and adults (25–35 years old). Furthermore, adult PDLSCs exhibited lower levels of mitophagy, impaired mitochondrial function, and a decreased ratio of RANKL/OPG compared to young PDLSCs after compression. Transfection of siRNA confirmed that inhibition of mitophagy in PDLSC resulted in decreased mitochondrial function and reduced RANKL/OPG ratio. Application of mitophagy inducer Urolithin A enhanced bone remodeling and accelerated OTM in rats, while the mitophagy inhibitor Mdivi‐1 had the opposite effect. These findings indicate that force‐stimulated PDLSC mitophagy contributes to alveolar bone remodeling during OTM, and age‐related impairment of mitophagy negatively impacts the PDLSC response to mechanical stimulus. Our findings enhance the understanding of mitochondrial mechanotransduction and offer new targets to tackle current clinical challenges in orthodontic therapy. [ABSTRACT FROM AUTHOR]

Non-coding RNA has many types which has rich functions and plays an important role in the study of basic molecular mechanisms. Many non-coding RNA have important implications for pluripotent stem cells and embryonic stem cells. It has been found to affect the self-renewal and osteogenesis of many types of stem cells. They have also been found to regulate stem cell proliferation and induct bone differentiation. Periodontal ligament stem cells are essential for the regeneration of periodontal tissue. In recent years, in the field of stomatology, studies have found that many non-coding RNA also have significant regulatory effects on the proliferation and differentiation of periodontal stem cells and may become potential therapeutic targets for many common periodontal diseases such as periodontitis, bone/tooth/soft tissue loss and orthodontic treatment. Therefore, we summarized the current research status of non-coding RNA in the field of molecular mechanism of periodontal ligament stem cells and prospected its future progress. [ABSTRACT FROM AUTHOR]

Background: Periodontitis is a chronic inflammatory disease mediated by dysbiosis of the oral microflora, resulting in the destruction of periodontal tissue. Increasing evidence suggested that mesenchymal stem cell (MSCs) and exosomes derived from MSCs play a critical role in periodontal tissue regeneration. However, whether stem cells from exfoliated deciduous teeth (SHED)‐secreted exosomes can improve the therapeutic potential of periodontitis is largely unknown. Objective: Here, we aim to evaluate the effect of SHED‐exosomes on inflammation, apoptosis and osteogenic differentiation in periodontitis. Methods: The periodontitis cell model was constructed by stimulating periodontal ligament stem cells (PDLSCs) with lipopolysaccharide (LPS), and the periodontitis rats were established by ligation. Results: First, we isolated exosomes from the SHED, and we figured out that exosomes secreted by SHED were enriched in miR‐92a‐3p and the exosomes enhanced proliferation and osteogenic differentiation and reduced apoptosis and inflammatory responses in PDLSCs. In addition, we found that SHED‐exosomes alleviated inflammatory effect and elevated the expression of osteogenic‐related genes in periodontitis rat model. Moreover, miR‐92a‐3p targeted downstream Krüppel‐Like Transcription Factor 4 (KLF4) and regulated the PI3K/AKT pathway. Finally, our data indicated that upregulation of KLF4 or activation of PI3K/AKT by 740Y‐P counteracted the inhibitory effect of SHED‐exosomes on periodontitis progression. Conclusion: Taken together, our finding revealed that exosomal miR‐92a‐3p derived from SHED contributed to the alleviation of periodontitis development and progression through inactivating the KLF4/PI3K/AKT signaling pathway, which may provide a potential target for the treatment of periodontitis. [ABSTRACT FROM AUTHOR]

Objectives: Type 2 diabetes (T2DM), a recognized risk factor for periodontitis, is characterized by insulin resistance. However, the molecular mechanisms concerning the role of insulin resistance in linking T2DM and periodontitis remain poorly elucidated due to the absence of an appropriate T2DM cell model. We aimed to explore an appropriate model of T2DM in human periodontal ligament stem cells (hPDLSCs) and uncover the involved mechanisms. Materials and Methods: hPDLSCs were incubated with common reagents for recapitulating insulin resistance state including high glucose (HG) (15, 25, 35, 45 mM), glucosamine (0.8, 8, 18, 28, 38 mM), or palmitic acid (PA; 100, 200, 400, 800 μM), combined with LPS for 48 h. The insulin signaling pathway, inflammation, and pyroptosis were detected by western blots and quantitative real‐time polymerase chain reaction (RT–qPCR). The effects on osteogenesis were evaluated by alkaline phosphatase staining, alizarin red S staining, RT–qPCR, and western blots. Results: HG failed to recapitulate insulin resistance. Glucosamine was sufficient to induce insulin resistance but failed to trigger inflammation. In total, 100 and 200 μM PA exhibited the most proinflammatory, insulin resistance, and pyroptosis induced role, and inhibited the osteogenic differentiation of hPDLSCs. Conclusion: Palmitic acid is a promising candidate for developing T2DM model in hPDLSCs. [ABSTRACT FROM AUTHOR]

Background: Teeth and supporting oral tissues are attractive and accessible sources of stem cells. Periodontal ligament stem cells (PDLSC) are readily isolated from extracted third molars, and exhibit the ability to self‐renew and differentiate into multiple mesodermal cell fates. Clinical experience suggests that the exact location of periodontal defects affects the oral bone remodeling and wound healing. Compared to the mandible, the maxilla heals quicker and more efficiently. Angiogenesis is key in tissue regeneration including dental tissues, yet few studies focus on the angiogenic potential of PDLSC, none of which considered the differences between upper and lower jaw PDLSC (u‐PDLSC and l‐PDLSC, respectively). Methods: Here we studied the angiogenic potential of u‐PDLSC and l‐PDLSC and compared the results to well‐established mesenchymal stem cells (MSC). Cells were characterized in terms of surface markers, proliferation, and vascular endothelial growth factor (VEGF) secretion, and angiogenic assays were performed. Newly formed capillaries were stained with CD31, and their expression of platelet endothelial cell adhesion molecule (PECAM‐1), angiopoietin 2 (ANGPT2), and vascular endothelial growth factor receptor 1 and 2 (VEGFR‐1, VEGFR‐2) were measured. Results: Periodontal stem cells from the upper jaw showed a higher proliferation capacity, secreted more VEGF, and formed capillary networks faster and denser than l‐PDLSC. Gene expression of angiogenesis‐related genes was significantly higher in u‐PDLSC than in l‐PDLSC or MSC, given that culture conditions were suitable. Conclusion: The oral cavity is a valuable source of stem cells, particularly PDLSC, which are promising for oral tissue engineering due to their robust growth, lifelong accessibility, low immunogenicity, and strong differentiation potential. Notably, u‐PDLSC exhibit higher VEGF secretion and accelerate capillary formation compared to l‐PDLSC or MSC. This study suggests a potential molecular mechanism in capillary formation, emphasizing the significance of precise location isolation of PDLSC. [ABSTRACT FROM AUTHOR]

Posttranslational modifications (PTMs) are crucial regulatory mechanisms for cellular differentiation and organismal development. Acylation modification is one of the main PTMs that plays a pivotal role in regulating the osteogenic differentiation of mesenchymal stem cells and is a focal point of research in bone tissue regeneration. However, its mechanism remains incompletely understood. This article aims to investigate the impact of protein crotonylation on osteogenic differentiation in periodontal ligament stem cells (PDLSCs) and elucidate its underlying mechanisms. Western blot analysis identified that the modification level of acetylation, crotonylation, and succinylation were significantly upregulated after osteogenic induction of PDLSCs. Subsequently, sodium crotonate (NaCr) was added to the medium and acyl-CoA synthetase short-chain family member 2 (ACSS2) was knocked down by short hairpin RNA plasmids to regulate the total level of protein crotonylation. The results indicated that treatment with NaCr promoted the expression of osteogenic differentiation-related factors in PDLSCs, whereas silencing ACSS2 had the opposite effect. In addition, mass spectrometry analysis was used to investigate the comprehensive analysis of proteome-wide crotonylation in PDLSCs under osteogenic differentiation. The analysis revealed that the level of protein crotonylation related to the PI3K-AKT signaling pathway was significantly upregulated in PDLSCs after osteogenic induction. Treatment with NaCr and silencing ACSS2 affected the activation of the PI3K-AKT signaling pathway. Collectively, our study demonstrates that protein crotonylation promotes osteogenic differentiation of PDLSCs via the PI3K-AKT pathway, providing a novel targeting therapeutic approach for bone tissue regeneration. [ABSTRACT FROM AUTHOR]

To investigate the effect and mechanism of sanguinarine (SAN) on osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) treated with tumor necrosis factor-α (TNF-α). hPDLSCs were divided into 6 groups: Control group, TNF-α group, TNF-α+0.1SAN group, TNF-α+1SAN group, TNF-α+10SAN group and TNF-α+100SAN group. All hPDLSCs were cultured in osteogenic induction medium. Except Control group, 10 ng/mL TNF-α was added to the culture medium of other groups. 0, 0.1, 1, 10, 100 μmol/L sanguinarine were added to the culture medium of TNF-α+0.1SAN group, TNF-α+1SAN group, TNF-α+10SAN group and TNF-α+100SAN group, respectively. HPDLSCs of all groups were cultured at 37 ℃ and 5% CO2 for 21 days. The activity of alkaline phosphatase (ALP) was detected by visible light colorimetry. The formation of calcified nodules was observed by alizarin red staining, and OD562 nm (representing the amount of calcified nodules) was counted. The transcription levels of Runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), osterix (OSX), cementum attachment protein (CAP) and Smad4 were detected by qRT-PCR. The phosphorylation level of NF-kappa B (NF-κB) p65 was detected by Western blot. Compared with that in the Control group, the relative ALP activity, amount of calcified nodules, and the relative expression of RUNX2, OCN, OSX, CAP and Smad4 mRNA in TNF-α group decreased (P<0.05), while p-NF-κB p65/NF-κB p65 increased (P<0.05). Compared with that in the TNF-α group, the relative ALP activity, amount of calcified nodules, RUNX2, OCN, OSX, CAP and Smad4 mRNA expression of TNF-α+1SAN group, TNF-α+10SAN group and TNF-α+100SAN group increased (P<0.05), while p-NF-κB p65/NF-κB p65 decreased (P<0.05). Sanguinarine can promote the osteogenic differentiation of hPDLSCs treated with TNF-α, and the mechanism may be related to the inhibition of the activation of NF-κB. Sanguinarine may be a candidate drug to promote the osteogenic differentiation of hPDLSCs in inflammatory microenvironment. [ABSTRACT FROM AUTHOR]

Abstract Background Bone defects in the maxillofacial region restrict the integrity of dental function, posing challenges in clinical treatment. Bone tissue engineering (BTE) with stem cell implants is an effective method. Nanobiomaterials can effectively enhance the resistance of implanted stem cells to the harsh microenvironment of bone defect areas by promoting cell differentiation. Graphene oxide quantum dots (GOQDs) are zero-dimensional nanoscale derivatives of graphene oxide with excellent biological activity. In the present study, we aimed to explore the effects of GOQDs prepared by two methods (Y-GOQDs and B-GOQDs) on the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs), as well as the effect of gelatin methacryloyl (GelMA)-encapsulated GOQD-induced hPDLSC sheets on the repair of mandibular periodontal defects in rats. We also explored the molecular biological mechanism through which GOQD promotes bone differentiation. Results There were significant differences in oxygen-containing functional groups, particle size and morphology between Y-GOQDs and B-GOQDs. Y-GOQDs promoted the osteogenic differentiation of hPDLSCs more effectively than did B-GOQDs. In addition, GelMA hydrogel-encapsulated Y-GOQD-induced hPDLSC cell sheet fragments not only exhibited good growth and osteogenic differentiation in vitro but also promoted the repair of mandibular periodontal bone defects in vivo. Furthermore, the greater effectiveness of Y-GOQDs than B-GOQDs in promoting osteogenic differentiation is due to the regulation of hPDLSC mitochondrial dynamics, namely, the promotion of fusion and inhibition of fission. Conclusions Overall, Y-GOQDs are more effective than B-GOQDs at promoting the osteogenic differentiation of hPDLSCs by regulating mitochondrial dynamics, which ultimately contributes to bone regeneration via the aid of the GelMA hydrogels in vivo. Graphical Abstract

Abstract Background Periodontal ligament stem cells (PDLSCs) have been proposed as therapeutic candidates in periodontal diseases and periodontium defects. Paracrine factors of PDLSCs, namely, secretome, can contribute to tissue regeneration comparable to direct stem cell application. This study explored restoration effects of PDLSC-derived secretome/conditioned medium (PDLSC-CM) on PDLSCs themselves in an inflammatory microenvironment and identified its action mechanisms using proteomics and transcriptomic profiling. Methods PDLSC-CM was prepared from cells under healthy culture conditions. Mass spectrometry and liquid chromatography–tandem mass spectrometry (LC–MS/MS) were then performed to analyze the PDLSC-CM proteome. Osteogenic differentiation of PDLSCs under inflammatory conditions or in the presence of PDLSC-CM was then characterized in assays of alkaline phosphatase activity, intracellular calcium levels, protein expression of osteogenic markers, and matrix mineralization. Furthermore, the transcriptomic profile was assessed to identify significantly enriched signaling pathways and associated molecular networks by RNA sequencing. Results LC–MS/MS proteomics identified a total of 203 proteins and distinguished 187 significant protein changes in PDLSC-CM compared to control-CM. LPS-treated PDLSCs significantly attenuated osteogenic differentiation. When PDLSCs were treated with PDLSC-CM alone, their osteogenic activity was significantly upregulated compared to the control group. Moreover, the LPS-impaired osteogenesis of PDLSCs was reconstituted by PDLSC-CM treatment. RNA sequencing revealed 252, 1,326, and 776 differentially expressed genes in the control vs. LPS, control vs. PDLSC-CM, and LPS vs. LPS + PDLSC-CM groups, respectively. Conclusion This study suggest that PDLSC-CM restores the osteogenic potential of PDLSCs in an inflammatory environment through secretory functions representing potential repair and regenerative mechanisms.

BACKGROUND: Reactive oxygen species is a double-edged sword in the development of periodontitis and the regeneration of periodontal tissue. Low concentration of reactive oxygen species induces the differentiation of periodontal fibroblasts, and excessive reactive oxygen species will cause damage to periodontal tissue. In the process of inflammation, the accumulation of reactive oxygen species in periodontal tissue induces damage to cells and tissues through a variety of signaling pathways or through redox reactions. OBJECTIVE: To review the double-edged sword effect of reactive oxygen species in periodontitis and periodontal tissue regeneration, thereby providing potential targets and treatment ideas for the clinical treatment of periodontitis and periodontal tissue regeneration. METHODS: Databases of CNKI and PubMed were searched for relevant articles published from April 1990 to April 2023 with the key words of “periodontal tissue engineering, periodontal defect, regeneration of periodontal tissue, chronic periodontitis, reactive oxygen species, oxidative stress, antioxidative stress, oxidative injuries, free radicals, reactive nitrogen species” in Chinese and English, respectively. By reading the titles and abstracts, repetitive studies or irrelevant literatures were excluded. Finally, 77 articles were included for review. RESULTS AND CONCLUSION: Reactive oxygen species are a kind of free radicals with high reactivity. When bacteria invade, reactive oxygen species are released in large quantities by the respiratory explosion of neutrophils and play a double-edged sword role in the body through their redox reactions or as pleiotropic physiological signal transmitters. In periodontitis, low concentrations of reactive oxygen species can kill invading pathogenic bacteria, but high concentrations of reactive oxygen species promote the secretion of inflammatory factors through JNK, RANK, Wnt/β-Catenin and other pathways, promote immune damage or directly damage tissues through oxidative reactions or through other ways to aggravate periodontitis. In the process of periodontal tissue regeneration, low concentrations of reactive oxygen species can promote the proliferation and differentiation of periodontal ligament stem cells through Nrf2 and other pathways and can promote the secretion of vascular endothelial growth factor to promote vascular regeneration. This provides seeds and a nutrient environment for periodontal tissue regeneration, which is extremely important for promoting periodontal tissue regeneration. However, high concentrations of reactive oxygen species will reduce the activity of periodontal ligament stem cells and damage endothelial cells, which are not conducive to vascular regeneration. This will inhibit wound healing and periodontal tissue regeneration. Therefore, it is important to explore the role of reactive oxygen species in the development of periodontitis and periodontal tissue regeneration and to discover the potential mechanism of its action and to explore the appropriate concentration for its role in reducing periodontal inflammation and promoting periodontal tissue regeneration for the future treatment of periodontitis and periodontal tissue regeneration in clinical practice. Using reactive oxygen species as a target to explore ways to reduce periodontal inflammation and promote periodontal ligament stem cell activity and vascular regeneration may become a clinically effective method for treating periodontitis and promoting periodontal tissue regeneration. [ABSTRACT FROM AUTHOR]

Periodontal tissue regeneration is important for preserving teeth. Periodontal ligament stem cells (PDLSCs) are useful in periodontal tissue regeneration; however, tooth extraction is required to obtain these cells. Therefore, we focused on induced pluripotent stem (iPS) cells and established a method to obtain PDLSC-like cells from iPS cells. Specifically, we first differentiated iPS cells into neural crest–like cells (iNCs). Next, we obtained PDLSC-like cells (iPDLSCs) by culturing iNCs on extracellular matrix (ECM) derived from human primary periodontal ligament cells (HPDLCs). This differentiation method suggested that ECM derived from HPDLCs is important for iPDLSC differentiation. Thus, we aimed to identify the PDLSC-inducing factor present in HPDLC-derived ECM in this study. We first performed comprehensive analyses of HPDLC genes and identified fibrillin-2 (FBN2), an ECM-related factor. Furthermore, to clarify the effect of FBN2 on iPDLSC differentiation, we cultured iNCs using ECM derived from HPDLCs with FBN2 knocked down. As a result, expression of PDL-related markers was reduced in iNCs cultured on ECM derived from HPDLCs transfected with FBN2 siRNA (iNC-siFBN2) compared with iPDLSCs. Furthermore, the expression of CD105 (a mesenchymal stem cell marker), proliferation ability, and multipotency of iNC-siFBN2 were lower compared with iPDLSCs. Next, we cultured iNCs on FBN2 recombinant protein; however, expression of PDL-related markers did not increase compared with iPDLSC. The present results suggest the critical involvement of FBN2 in inducing iPDLSCs from iNCs when in fact it does not promote iPDLSC differantiation. Therefore, we need to elucidate the entire HPDLC-ECMs, responsible for iPDLSCs induction. [ABSTRACT FROM AUTHOR]

Objectives: Promoting the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) is a way to regenerate periodontal bone. This study aimed to determine whether lncRNA MALAT1 promotes the osteogenic differentiation of human PDLSCs in vitro. Materials and Methods: Human PDLSCs were extracted from the human periodontal ligament, and after osteogenic differentiation was induced using osteogenic medium, the human PDLSCs were transfected with siRNA‐MALAT1, miR‐93‐5p mimics, and miR‐93‐5p inhibitors. The expression of osteogenesis‐related genes was assessed by RT–qPCR and western blotting, alkaline phosphatase (ALP) activity was assessed by ALP activity assay, and the formation of mineralized nodules was assessed by alizarin red S (ARS) staining. RNA immunoprecipitation (RIP) and luciferase assays were performed to assess the binding of MALAT1, miR‐93‐5p, and SMAD5. Results: The expression of lncRNA metastasis‐associated lung adenocarcinoma transcript 1 (MALAT1) was upregulated, while that of miR‐93‐5p was downregulated after PDLSC osteogenic differentiation. Knockdown of MALAT1 inhibited the osteogenic differentiation of PDLSCs, and MALAT1 expression negatively correlated with miR‐93‐5p expression. miR‐93‐5p inhibited the osteogenic differentiation of human PDLSCs by specifically binding to SMAD5. Conclusion: MALAT1 regulates human PDLSC differentiation by regulating the miR‐93‐5p/SMAD5 axis. [ABSTRACT FROM AUTHOR]

Objective To observe the promotional effects of psoralen on proliferation and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs), and to explore their mechanism. Methods The third-generation hPDLSCs were divided into six groups: the control group and 5, 10, 25, 50 and 100 μmol/L psoralen groups, respectively. HPDLSCs in the 5, 10, 25, 50 and 100 μmol/L psoralen groups were treated with 5, 10, 25, 50 and 100 μmol/L psoralen, and hPDLSCs in the control group were cultured normally. Cell proliferation capacity was measured by CCK-8 assay, alkaline phosphatase (ALP) activity by colorimetric method, and mineralization nodules by alizarin red staining. Another third-generation hPDLSCs were divided into two groups: the control group and 25 μmol/L psoralen group. Cells in the 25 μmol/L psoralen group were treated with 25 μmol/L psoralen, while cells in the control group were cultured normally. Transcription factor 2 (Runx 2) and osteopontin (OPN) mRNA were detected by RT-PCR. Results Compared with the control group, cell proliferation capacity and ALP activity increased in the 5, 10, 25, 50 and 100 μmol/L psoralen groups, and mineralization nodules increased in the 25 μmol/L psoralen group (all P<0. 05) . Compared with the 5 μmol/L psoralen group, cell proliferative capacity increased in the 25, 50 and 100 μmol/L psoralen groups, ALP activity increased in the 10 and 25 μmol/L psoralen groups, and mineralization nodules increased in the 25 μmol/L psoralen group (all P<0. 05) . Compared with the 10 μmol/L psoralen group, cell proliferation capacity increased in the 25, 50 and 100 μmol/L psoralen groups (all P<0. 05) . Compared with the 25 μmol/L group, ALP activity decreased in the 50 and 100 μmol/L psoralen groups (all P<0. 05) . Compared with the control group, relative expression levels of Runx 2 and OPN mRNA increased in the 25 μmol/L psoralen group (all P<0. 05) . Conclusions Psoralen of 5-100 μmol/L promotes the proliferation and osteogenic differentiation of hPDLSCs. It shows a dose-dependent enhancement at 5 to 25 μmol/L, and there is no obvious change at 50 to 100 μmol/L. The mechanism of psoralen promoting the proliferation and osteogenic differentiation of hPDLSCs may be related to the regulation of Runx 2 signaling pathway. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) are a novel class of endogenous non-coding RNAs (ncRNAs) which unlike linear RNAs, have a covalently closed continuous loop structure. circRNAs are found abundantly in human cells and their biology is complex. They feature unique expression to different types of cells, tissues, and developmental stages. To the present, the functional roles of circular RNAs are not fully understood. They reportedly act as microRNA (miRNA) sponges, therefore having key regulatory functions in diverse physiological and pathological processes. As for dentistry field, lines of evidence indicate that circRNAs play vital roles in the odontogenic and osteogenic differentiation of dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs). Abnormal expression of circRNAs have been found in other areas of pathology frequently reflected also in the oral environment, such as inflammation or bone and soft tissue loss. Therefore, circRNAs could be of significant importance in various fields in dentistry, especially in bone and soft tissue engineering and regeneration. Understanding the molecular mechanisms occurring during the regulation of oral biological and tissue remodeling processes could augment the discovery of novel diagnostic biomarkers and therapeutic strategies that will improve orthodontic and other oral therapeutic protocols. [ABSTRACT FROM AUTHOR]

Objectives: Crocin is a major class of medicinal components in saffron. This study aimed to determine whether crocin directly promotes the proliferation and osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) in vitro and in vivo. Materials and Methods: CCK8 cell proliferation assay, reverse transcription quantitative polymerase chain reaction (RT–qPCR), Western blot analysis and Alizarin Red staining were performed in PDLSCs using crocin as a stimulant. DKK1 was used to selectively inhibit Wnt/β‐catenin signaling, and Western blotting was performed to investigate the underlying mechanism. The PDLSCs were mixed with calcium phosphate cement and implanted into nude mice subcutaneously to study the effect of crocin on PDLSC osteogenic differentiation in vivo. Results: The CCK‐8 assay showed that crocin did not promote the proliferation of PDLSCs. Treatment with 400 μM crocin significantly promoted PDLSC mRNA levels of ALP, COL1 and OCN; RUNX2 and BMP2 protein expression; mineralized nodule formation in vitro and in vivo; and ALP activity in tissues in vivo. In addition, crocin significantly promoted the phosphorylation of β‐catenin and cyclin D1. DKK1 inhibits Wnt/β‐catenin activation and partially reverses crocin‐mediated promotion of PDLSC osteogenic differentiation. Conclusion: Crocin may contribute to the regeneration of periodontal bone tissue. [ABSTRACT FROM AUTHOR]

Copyright of West China Journal of Stomatology is the property of Sichuan University, West China College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background and Objectives: Periodontitis is an immuno‐inflammatory disease caused by dental plaque biofilms and inflammations. The regeneration of bone tissue in inflammatory environment is of great significance for the treatment of periodontal disease, but the specific molecular mechanism of bone formation in periodontitis still needs further exploration. The objective of this study was to identify key osteogenesis‐related genes (ORGs) in periodontitis. Methods: We used two datasets from the Gene Expression Omnibus (GEO) database to find differentially expressed mRNAs and miRNAs, further performed Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Then we predicted the downstream genes of the differentially expressed miRNAs (DEMs) by the TargetScan database and established a miRNA‐mRNA regulatory network. Finally, the osteogenic mechanism of periodontitis was explored through quantitative real‐time PCR (qRT‐PCR) by inducing inflammatory environment and osteogenic differentiation of hPDLSCs. Results: Through differential expression analysis and prediction of downstream target genes of DEMs, we created a miRNA‐mRNA regulatory network consisting of 29 DEMs and 11 differentially expressed osteogenesis‐related genes (DEORGs). In addition, the qRT‐PCR results demonstrated that BTBD3, PLAT, AKAP12, SGK1, and GLCE expression levels were significantly upregulated, while those of TIMP3, ZCCHC14, LIN7A, DNAH6, NNT, and ITGA6 were downregulated under the dual effects of inflammatory stimulation and osteogenic induction. Conclusion: DEORGs might be important factors in the osteogenic phase of periodontitis, and the miRNA‐mRNA network may shed light on the clarification of the role and mechanism of osteogenesis in periodontitis and contribute to the development of novel therapeutic strategies. [ABSTRACT FROM AUTHOR]

Background: Bone defects in the maxillofacial region restrict the integrity of dental function, posing challenges in clinical treatment. Bone tissue engineering (BTE) with stem cell implants is an effective method. Nanobiomaterials can effectively enhance the resistance of implanted stem cells to the harsh microenvironment of bone defect areas by promoting cell differentiation. Graphene oxide quantum dots (GOQDs) are zero-dimensional nanoscale derivatives of graphene oxide with excellent biological activity. In the present study, we aimed to explore the effects of GOQDs prepared by two methods (Y-GOQDs and B-GOQDs) on the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs), as well as the effect of gelatin methacryloyl (GelMA)-encapsulated GOQD-induced hPDLSC sheets on the repair of mandibular periodontal defects in rats. We also explored the molecular biological mechanism through which GOQD promotes bone differentiation. Results: There were significant differences in oxygen-containing functional groups, particle size and morphology between Y-GOQDs and B-GOQDs. Y-GOQDs promoted the osteogenic differentiation of hPDLSCs more effectively than did B-GOQDs. In addition, GelMA hydrogel-encapsulated Y-GOQD-induced hPDLSC cell sheet fragments not only exhibited good growth and osteogenic differentiation in vitro but also promoted the repair of mandibular periodontal bone defects in vivo. Furthermore, the greater effectiveness of Y-GOQDs than B-GOQDs in promoting osteogenic differentiation is due to the regulation of hPDLSC mitochondrial dynamics, namely, the promotion of fusion and inhibition of fission. Conclusions: Overall, Y-GOQDs are more effective than B-GOQDs at promoting the osteogenic differentiation of hPDLSCs by regulating mitochondrial dynamics, which ultimately contributes to bone regeneration via the aid of the GelMA hydrogels in vivo. [ABSTRACT FROM AUTHOR]

Background: Periodontal ligament stem cells (PDLSCs) have been proposed as therapeutic candidates in periodontal diseases and periodontium defects. Paracrine factors of PDLSCs, namely, secretome, can contribute to tissue regeneration comparable to direct stem cell application. This study explored restoration effects of PDLSC-derived secretome/conditioned medium (PDLSC-CM) on PDLSCs themselves in an inflammatory microenvironment and identified its action mechanisms using proteomics and transcriptomic profiling. Methods: PDLSC-CM was prepared from cells under healthy culture conditions. Mass spectrometry and liquid chromatography–tandem mass spectrometry (LC–MS/MS) were then performed to analyze the PDLSC-CM proteome. Osteogenic differentiation of PDLSCs under inflammatory conditions or in the presence of PDLSC-CM was then characterized in assays of alkaline phosphatase activity, intracellular calcium levels, protein expression of osteogenic markers, and matrix mineralization. Furthermore, the transcriptomic profile was assessed to identify significantly enriched signaling pathways and associated molecular networks by RNA sequencing. Results: LC–MS/MS proteomics identified a total of 203 proteins and distinguished 187 significant protein changes in PDLSC-CM compared to control-CM. LPS-treated PDLSCs significantly attenuated osteogenic differentiation. When PDLSCs were treated with PDLSC-CM alone, their osteogenic activity was significantly upregulated compared to the control group. Moreover, the LPS-impaired osteogenesis of PDLSCs was reconstituted by PDLSC-CM treatment. RNA sequencing revealed 252, 1,326, and 776 differentially expressed genes in the control vs. LPS, control vs. PDLSC-CM, and LPS vs. LPS + PDLSC-CM groups, respectively. Conclusion: This study suggest that PDLSC-CM restores the osteogenic potential of PDLSCs in an inflammatory environment through secretory functions representing potential repair and regenerative mechanisms. [ABSTRACT FROM AUTHOR]

Periodontal defects' localization affects wound healing and bone remodeling, with faster healing in the upper jaw compared to the lower jaw. While differences in blood supply, innervation, and odontogenesis contribute, cell-intrinsic variances may exist. Few studies explored cell signaling in periodontal ligament stem cells (PDLSC), overlooking mandible-maxilla disparitiesUsing kinomics technology, we investigated molecular variances in PDLSC. Characterization involved stem cell surface markers, proliferation, and differentiation capacities. Kinase activity was analyzed via multiplex kinase profiling, mapping differential activity in known gene regulatory networks. Upstream kinase analysis identified stronger EphA receptor expression in the mandible, potentially inhibiting osteogenic differentiation. The PI3K-Akt pathway showed higher activity in lower-jaw PDLSC. PDLSC from the upper jaw exhibit superior proliferation and differentiation capabilities. Differential activation of gene regulatory pathways in upper vs. lower-jaw PDLSC suggests implications for regenerative therapies. [ABSTRACT FROM AUTHOR]

Segmental bone defects that are caused by trauma, infection, tumor resection, or osteoporotic fractures present significant surgical treatment challenges. Host bone autograft is considered the gold standard for restoring function but comes with the cost of harvest site comorbidity. Allograft bone is a secondary option but has its own limitations in the incorporation with the host bone as well as its cost. Therefore, developing new bone tissue engineering strategies to treat bone defects is critically needed. In the past three decades, the use of stem cells that are delivered with different scaffolds or growth factors for bone tissue engineering has made tremendous progress. Many varieties of stem cells have been isolated from different tissues for use in bone tissue engineering. This review summarizes the progress in using different postnatal stem cells, including bone marrow mesenchymal stem cells, muscle-derived stem cells, adipose-derived stem cells, dental pulp stem cells/periodontal ligament stem cells, periosteum stem cells, umbilical cord-derived stem cells, peripheral blood stem cells, urine-derived stem cells, stem cells from apical papilla, and induced pluripotent stem cells, for bone tissue engineering and repair. This review also summarizes the progress using exosomes or extracellular vesicles that are delivered with various scaffolds for bone repair. The advantages and disadvantages of each type of stem cell are also discussed and explained in detail. It is hoped that in the future, these preclinical results will translate into new regenerative therapies for bone defect repair. [ABSTRACT FROM AUTHOR]

Objective: Periodontitis is characterized by alveolar bone injury and absorption, with high incidence and poor treatment effect. Proliferation, migration, differentiation and apoptosis of osteoblasts are identified as key factors during the regeneration of alveolar bone tissue processes. Periodontal ligament stem cells (PDLSCs) have been proved to be a possible candidate for the treatment of periodontitis due to its multiple advantages, such as increasing the regenerative capacity of bone tissue. However, the effect of exosomes derived from PDLSCs (PDLSC‐Exo) on osteoblasts remains to be further studied. Methods and Materials: In this work, cell proliferation, migration, osteogenic differentiation, and H2O2‐induced apoptosis were detected after cells were exposed to PDLSC‐Exo by CCK‐8, scratch wound assay, alizarin red S and alkaline phosphatase staining, real‐time PCR, flow cytometry, tunel assay, and so on. Moreover, the activation of PI3K/AKT and MEK/ERK signaling pathways was evaluated by western blotting. Results: We found that PDLSC‐Exo are capable of promoting hFOB1.19 cell proliferation, migration and osteogenic differentiation, inhibiting H2O2‐induced apoptosis, and activating the PI3K/AKT and MEK/ERK signaling pathways. Conclusion: These results suggest that PDLSC‐Exo may be a promising therapeutic for osteoblastic damage. [ABSTRACT FROM AUTHOR]

Abstract Low level laser treatment (LLLT) is known for its photobiostimulatory and photobiomodulatory characteristics, which stimulate cell proliferation, increase cellular metabolism, and improve cellular regeneration. The objective of the present research was to assess the possible influence of infrared diode laser irradiation on the behaviour, attachment, and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) seeded on different types of dental implants. Two distinct types of implants, one subjected to laser surface treatment and the other treated with acid etching, were longitudinally divided into two halves and submerged in six wells culture plates. Both implants were subjected to infrared diode laser treatment, and subsequently, the morphology and attachment of cells were examined using scanning electron microscopy (SEM) after 14 and 21 days. The behaviour of (hPDLSCs) towards two types of implants, when exposed to osteogenic medium and low-level laser therapy (LLLT), was assessed using quantitative real-time polymerase chain reaction to measure the expression of stemness markers and osteogenic markers. The scanning electron microscopy (SEM) demonstrated that the application of infrared diode laser irradiation substantially improved the attachment of cells to both types of implants. The stemness gene markers were significantly down regulated in cells seeded on both surfaces when challenged with osteogenic media in relation to control. At 14 days, early osteogenic markers, were upregulated, while late osteogenic markers, were downregulated in both challenged groups. At the 21-day mark, hPDLSCs seeded on an acid-etched implant exhibited increased expression of all osteogenic markers in response to stimulation with osteogenic media and infra-red diode laser, in contrast to hPDLSCs seeded on a laser surface treated implant under the same conditions. Finally, the findings of our research revealed that when subjected to infrared diode laser, human periodontal ligament stem cells cultured on both types of implants demonstrated improved cellular attachment and differentiation. This suggested that infrared diode laser enhanced the activity of the cells surrounding the implants. Hence, the use of infrared diode laser could be pivotal in improving and expediting the clinical osseointegration process around dental implants.

Low level laser treatment (LLLT) is known for its photobiostimulatory and photobiomodulatory characteristics, which stimulate cell proliferation, increase cellular metabolism, and improve cellular regeneration. The objective of the present research was to assess the possible influence of infrared diode laser irradiation on the behaviour, attachment, and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) seeded on different types of dental implants. Two distinct types of implants, one subjected to laser surface treatment and the other treated with acid etching, were longitudinally divided into two halves and submerged in six wells culture plates. Both implants were subjected to infrared diode laser treatment, and subsequently, the morphology and attachment of cells were examined using scanning electron microscopy (SEM) after 14 and 21 days. The behaviour of (hPDLSCs) towards two types of implants, when exposed to osteogenic medium and low-level laser therapy (LLLT), was assessed using quantitative real-time polymerase chain reaction to measure the expression of stemness markers and osteogenic markers. The scanning electron microscopy (SEM) demonstrated that the application of infrared diode laser irradiation substantially improved the attachment of cells to both types of implants. The stemness gene markers were significantly down regulated in cells seeded on both surfaces when challenged with osteogenic media in relation to control. At 14 days, early osteogenic markers, were upregulated, while late osteogenic markers, were downregulated in both challenged groups. At the 21-day mark, hPDLSCs seeded on an acid-etched implant exhibited increased expression of all osteogenic markers in response to stimulation with osteogenic media and infra-red diode laser, in contrast to hPDLSCs seeded on a laser surface treated implant under the same conditions. Finally, the findings of our research revealed that when subjected to infrared diode laser, human periodontal ligament stem cells cultured on both types of implants demonstrated improved cellular attachment and differentiation. This suggested that infrared diode laser enhanced the activity of the cells surrounding the implants. Hence, the use of infrared diode laser could be pivotal in improving and expediting the clinical osseointegration process around dental implants. [ABSTRACT FROM AUTHOR]

Background: Toll‐like receptor 4 (TLR4)‐mediated inflammatory responses are associated with diabetes and periodontitis, which are dysregulated by O‐GlcNAcylation. Objective: This study aimed to investigate the effects of O‐GlcNAc transferase (OGT)‐mediated TLR4 O‐GlcNAcylation on the osteogenesis of periodontal ligament stem cells (PDLCs). Methods: PDLCs were treated with high glucose (HG) to establish a cell model. Osteogenic differentiation was evaluated using western blotting, an alkaline phosphatase activity assay, and an alizarin red S staining assay. The regulation of OGT on the O‐GlcNAcylation of TLR4 was analyzed using co‐immunoprecipitation, immunoprecipitation, western blotting, and immunofluorescence staining. Results: The results showed that HG inhibited osteogenic differentiation and promoted inflammatory response. Knockdown of OGT promoted osteogenic differentiation of HG‐treated PDLCs. OGT interacted with TLR4 and increased the O‐GlcNAcylation and protein levels of TLR4 in the cytomembrane of PDLCs. Moreover, silenced TLR4 reversed the effects on osteogenic differentiation induced by OGT in HG‐treated PDLCs. Conclusion: O‐GlcNAcylation of TLR4 induced by OGT suppresses osteogenic differentiation of PDLCs after HG stimulation. The findings suggest a promising strategy for treating DP. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Prevention & Treatment For Stomatological Diseases is the property of Journal of Prevention & Treatment For Stomatological Diseases Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: To develop a stem cell delivery model and improve the safety of stem cell transplantation for bone regeneration, this study aimed to determine the effects of stem cell sources, serum-free cell culture, and hydrogel cell encapsulation on the growth and osteogenic differentiation of mesenchymal stem cells (MSCs) from the oral cavity. Methods: The study groups were categorized according to stem cell sources into buccal fat pad adipose (hBFP-ADSCs) (Groups 1, 4, and 7), periodontal ligament (hPDLSCs) (Groups 2, 5, and 8), and dental pulp-derived stem cells (hDPSCs) (Groups 3, 6, and 9). MSCs from each source were isolated and expanded in three types of sera: fetal bovine serum (FBS) (Groups 1–3), human serum (HS) (Groups 4–6), and synthetic serum (SS) (StemPro™ MSC SFM) (Groups 7–9) for monolayer (m) and hydrogel cell encapsulation cultures (e). Following this, the morphology, expression of MSC cell surface antigens, growth, and osteogenic differentiation potential of the MSCs, and the expression of adhesion molecules were analyzed and compared. Results: SS decreased variations in the morphology and expression levels of cell surface antigens of MSCs from three cell sources (Groups 7m–9m). The levels of osteoblastic differentiation of the hPDLSCs and hBFP-ADSCs were increased in SS (Groups 8m and 7m) and the cell encapsulation model (Groups 1e, 4e, 7e–9e), but the promoting effects of SS were decreased in a cell encapsulation model (Groups 7e–9e). The expression levels of the alpha v beta 3 (ITG-αVβ3) and beta 1 (ITG-β1) integrins in the encapsulated cells in FBS (Group 1e) were higher than those in the SS (Group 7e). Conclusions: Human PDLSCs and BFP-ADSCs were the optimum stem cell source for stem cell encapsulation by using nanohydroxyapatite–calcium carbonate microcapsule–chitosan/collagen hydrogel in serum-free conditions. [ABSTRACT FROM AUTHOR]

In regenerative bone tissue medicine, combining artificial bone substitutes with progenitor cells is a prospective approach. Surface modification via cold atmospheric plasma (CAP) enhances biomaterial–cell interactions, which are crucial for successful bone regeneration. Using a rabbit calvarial critical-size defect model, we assessed the use of CAP-pretreated beta-tricalcium phosphate (β-TCP), alone or with periodontal ligament stem cells (PDLSCs), for bone regeneration. Histological and histomorphometric analyses at two and four weeks revealed significantly improved bone regeneration and reduced inflammation in the CAP-treated β-TCP with PDLSCs compared to β-TCP alone. Immunohistochemical analysis also showed an increase in the bone healing markers, including bone morphogenic proteins 2 and 4, runt-related transcription factor 2, collagen-1, and osteonectin, after two and four weeks in the CAP-treated β-TCP implants with PDLSC. This in vivo study demonstrates for the first time the superior bone regenerative capacity of CAP-pretreated β-TCP seeded with PDLSCs, highlighting the therapeutic potential of this combined approach in osteoregeneration. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate the effect of proanthocyanidin (PA) on osteogenesis mediated by periodontal ligament stem cells (PDLSCs) and endogenous alveolar bone regeneration. Background: Leveraging the osteogenic potential of resident stem cells is a promising strategy for alveolar bone regeneration. PA has been reported to be effective in osteogenesis. However, the effect and mechanism of PA on the osteogenic differentiation of PDLSCs remain elusive. Methods: Human PDLSCs were treated with various doses of PA to assess the cell proliferation using Cell Counting Kit‐8. The osteogenic differentiation ability was detected by qRT‐PCR analysis, western blot analysis, Alizarin red S staining, and Alkaline Phosphatase staining. The level of autophagy was evaluated by confocal laser scanning microscopy, transmission electron microscopy, and western blot analysis. RNA sequencing was utilized to screen the potential signaling pathway. The alveolar bone defect model of rats was created to observe endogenous bone regeneration. Results: PA activated intracellular autophagy in PDLSCs, resulting in enhanced osteogenic differentiation. Moreover, this effect could be abolished by the autophagy inhibitor 3‐Methyladenine. Mechanistically, the PI3K/Akt/mTOR pathway was negatively correlated with PA‐mediated autophagy activation. Lastly, PA promoted the alveolar bone regeneration in vivo, and this effect was reversed when the autophagy process was blocked. Conclusion: PA may activate autophagy by inhibiting PI3K/Akt/mTOR signaling pathway to promote the osteogenesis of PDLSCs and enhance endogenous alveolar bone regeneration. [ABSTRACT FROM AUTHOR]

Background: Periodontal ligament stem cells (PDLSCs) are the most potential cells in periodontal tissue regeneration and bone tissue regeneration. Our prior work had revealed that WD repeat‐containing protein 72 (WDR72) was crucial for osteogenic differentiation of PDLSCs. Here, we further elucidated its underlying mechanism in PDLSC osteogenic differentiation. Methods: Human PDLSCs, isolated and identified by flow cytometry, were prepared for osteogenic differentiation induction. Levels of WDR72, long non‐coding RNA X‐Inactive Specific Transcript (XIST), upstream stimulatory factor 2 (USF2), and osteogenic marker genes (Runx2, Osteocalcin, and Collagen I) in human PDLSCs and clinical specimens were detected by RT‐qPCR. Protein expressions of WDR72, Runx2, Osteocalcin, and Colla1 were tested by Western blot. The interactions among the molecules were verified by RIP, RNA pull‐down, ChIP, and luciferase reporter assays. Osteogenic differentiation was evaluated by alkaline phosphatase (ALP) and alizarin red staining (ARS). Results: WDR72 was decreased in periodontal tissues of periodontitis patients, and overexpression reversed TNF‐α‐mediated suppressive effects on PDLSC osteogenic differentiation. Mechanically, XIST recruited the enrichment of USF2 to the WDR72 promoter region, thereby positively regulating WDR72. WDR72 silencing overturned XIST‐mediated biological effects in PDLSCs. Conclusion: WDR72, regulated by the XIST/USF2 axis, enhances osteogenic differentiation of PDLSCs, implying a novel strategy for alleviating periodontitis. [ABSTRACT FROM AUTHOR]

PDLSCs possess multidirectional differentiation potential and self-renewal ability. In the inflammatory environment, signalling pathways, such as Wnt/β-catenin, Wnt/Ca2+, Wnt/PCP, NF-κB, MAPK, BMPs, and PI3K/AKT, are involved in regulating the osteogenic differentiation of PDLSCs. In addition, multiple signalling pathways that interact with microRNAs play crucial roles in the osteogenic differentiation of PDLSCs.

Abstract Background The key to the success of endogenous regeneration is to improve the homing rate of stem cells, and low-energy laser is an effective auxiliary means to promote cell migration and proliferation. The purpose of this study was to observe whether low-energy neodymium (Nd: YAG) laser with appropriate parameters can affect the proliferation and migration of periodontal ligament stem cells (PDLSCs) through SDF-1/CXCR4 pathway. Methods h PDLSCs were cultured and identified. CCK8 assay was used to detect the proliferation of h PDLSCs after different power (0, 0.25, 0.5, 1, and 1.5 W) Nd: YAG laser (MSP, 10 Hz, 30 s, 300 μ m) irradiation at 2th, 3rd,5th, and 7th days, and the optimal laser irradiation parameters were selected for subsequent experiments. Then, the cells were categorized into five groups: control group (C), SDF-1 group (S), AMD3100 group (A), Nd: YAG laser irradiation group (N), and Nd: YAG laser irradiation + AMD3100 group (N + A). the migration of h PDLSCs was observed using Transwell, and the SDF-1 expression was evaluated using ELISA andRT-PCR. The SPSS Statistics 21.0 software was used for statistical analysis. Results The fibroblasts cultured were identified as h PDLSCs. Compared with the C, when the power was 1 W, the proliferation rate of h PDLSCs was accelerated (P 0.05). The number of cell perforations values as follows: C (956.5 ± 51.74), A (981.5 ± 21.15), S (1253 ± 87.21), N (1336 ± 48.54), and N + A (1044 ± 22.13), that increased significantly in group N (P

Objectives: To investigate the effect of three different calcium silicate-based materials (CSBM) on the biological behavior of human periodontal ligament stem cells (hPDLSCs). Methods: Eluates of Biodentine, NeoPutty and TheraCal PT prepared at 1:1, 1:2, and 1:4 ratios were extracted under sterile conditions. The cytotoxicity of the extracts to the hPDLSCs was assessed using the MTT assay. Scratch wound healing assay was utilized for assessing cell migration. Scanning electron microscopy was used to detect cell attachment and morphology. Calcium ion release was measured using inductively coupled plasma-optical emission spectrometry; the pH-value was evaluated with a pH-meter. ANOVA with post hoc Tukey test was used for statistical analysis. Results: Cell viability was significantly higher for Biodentine and NeoPutty at day 1 with all dilutions (p < 0.05), while at day 3 and day 7 with dilutions 1:2 and 1:4; all materials showed similar behavior (p > 0.05). Biodentine had the highest percentage of cell migration into the scratched area at day 1 for all dilutions (p < 0.05). Stem cells were attached favorably on Biodentine and NeoPutty with evident spreading, and intercellular communications; however, this was not shown for TheraCal PT. Biodentine showed the highest pH values and calcium ion release (p < 0.05). Conclusions: The resin-free CSBM showed better performance and favorable biological effects on hPDLSCs and were therefore considered promising for usage as endodontic repair materials. Clinical significance: Proper selection of materials with favorable impact on the host stem cells is crucial to ensure outcome in different clinical scenarios. [ABSTRACT FROM AUTHOR]

BACKGROUND: Periodontal disease is a chronic inflammation of tooth supporting tissue. The destruction of these tissues leads to tooth loss. Periodontal tissue regeneration is the ultimate goal of periodontal therapy. OBJECTIVE: To review the biological characteristics of periodontal ligament stem cells and their influencing factors in promoting periodontal tissue regeneration. METHODS: Databases of PubMed, CNKI, Wanfang, ScienceDirect, and Medline were retrieved with the key words of “periodontal ligament stem cells, periodontal tissue regeneration” in English and Chinese for articles published from 2004 to 2021. The articles were screened according to the inclusion and exclusion criteria and finally 72 articles were included for review. RESULTS AND CONCLUSION: Periodontitis is a widespread disease characterized by inflammation leading to progressive damage to tooth support structures until teeth fall off. A grand goal of periodontal regeneration therapy is to repair the lost or damaged supporting tissues in periodontal tissue, including alveolar bone, periodontal ligament and cementum, and may effectively reduce the tooth loss caused by periodontitis. Stem cells for periodontal regeneration are the focus of regeneration research and it is also a potential treatment for periodontitis. Periodontal ligament stem cells may be the most suitable cells as cell sources. The in-depth study of biology also emphasizes that periodontal ligament stem cells are promising immunomodulators. However, there are a variety of factors that enhance or inhibit the role of periodontal ligament stem cells in periodontal tissue regeneration. Understanding the influence mechanism of various factors will help us to have more in-depth research in this field. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cannabidiol, one of the major non-psychotomimetic components from plant Cannabis sativa, has anti-inflammatory, antioxidant, and other pharmacological activities. Recently, it was shown that cannabidiol could effectively promote the osteogenic differentiation of preosteoblasts and mesenchymal stem cells. However, the effect of cannabidiol on the proliferation and osteogenic differentiation of human periodontal ligament stem cells remains unclear. OBJECTIVE: To investigate the effects of cannabidiol on the proliferation and osteogenic differentiation of human periodontal ligament stem cells. METHODS: Human periodontal ligament stem cells were isolated and cultured using explant method. Cell identification was performed by morphological observation, flow cytometry analysis, and multidirectional differentiation assay. CCK-8 assay was used to assess the effect of different concentrations of cannabidiol (0.1, 0.5, 2.5, 12.5 μmol/L) on the proliferation of human periodontal ligament stem cells. Alkaline phosphatase activity assay, Alizarin Red S staining and semi quantitative analysis were performed to assess different concentrations of cannabidiol (0.1, 0.5, 2.5 μmol/L) on the osteogenic differentiation of human periodontal ligament stem cells. Osteogenic differentiation-related gene expression level changes were assessed by qPCR. RESULTS AND CONCLUSION: (1) 0.1 μmol/L cannabidiol showed no significant effect on the viability of human periodontal ligament stem cells; 0.5 and 2.5 μmol/L cannabidiol significantly increased cell proliferation, whereas 12.5 μmol/L cannabidiol had obvious cytotoxicity. (2) 0.1-2.5 μmol/L cannabidiol significantly enhanced alkaline phosphatase activity and mineral deposition of human periodontal ligament stem cells, and upregulated the expression of osteogenic related genes COL 1, OCN, RUNX2, and β-catenin. (3) In conclusion, cannabidiol promoted proliferation and osteogenic differentiation of human periodontal ligament stem cells in a concentration dependent manner, with the most significant effect at 2.5 μmol/L, which may be related to Wnt/β-catenin signaling pathway. [ABSTRACT FROM AUTHOR]

Periodontitis is an inflammatory disease characterized by alveolar bone loss. Periodontal ligament stem cells (PDLSCs) have osteogenic differentiation potential, which can be influenced by epigenetics regulation in periodontitis. Therefore, this review aimed to shed light on the role of different epigenetic mechanisms in the osteogenic differentiation of PDLSCs and to consider the prospects of their possible therapeutic applications in periodontitis. Databases MEDLINE (through PubMed) and Web of Science were searched for the current knowledge of epigenetics in osteogenic differentiation of PDLSCs using the keywords "periodontal ligament stem cells", "epigenetic regulation", "epigenetics", "osteogenic differentiation", and "osteogenesis". All studies introducing epigenetic regulation and PDLSCs were retrieved. This review shows that epigenetic factors like DNMT, KDM6A, HDACi, some miRNAs, and lncRNAs can induce the osteogenic differentiation of PDLSCs in the noninflammatory microenvironment. However, the osteogenic differentiation of PDLSCs is inhibited in the inflammatory microenvironment through the upregulated DNA methylation of osteogenesis‐related genes and specific changes in histone modification and noncoding RNA. Epigenetics of osteogenic differentiation of PDLSCs in inflammation exhibits the contrary effect compared with a noninflammatory environment. The application of epigenetic drugs to regulate the abnormal epigenetic status in periodontitis and focus on alveolar bone regeneration is promising. [ABSTRACT FROM AUTHOR]