Quercetin-Loaded Bioglass Injectable Hydrogel Promotes m6A Alteration of Per1 to Alleviate Oxidative Stress for Periodontal Bone Defects.

Periodontal disease ranks third among noncommunicable illnesses, behind cancer and cardiovascular disease, and is closely related to the occurrence and progression of various systemic diseases. However, elucidating the processes of periodontal disease and promoting periodontal bone regeneration remains a challenge. Here, quercetin is demonstrated to reduce the oxidative stress state of orofacial mesenchymal stem cells (OMSCs) in vitro and to affect the osteogenic growth of OMSCs through molecular mechanisms that mediate the m6A change in Per1. Nevertheless, the limited therapeutic efficacy of systemic medication and the limitations of local medication resulting from the small, moist, and highly dynamic periodontal environment make it challenging to treat periodontal tissues with medication. Herein, a biosafe injectable hydrogel drug-controlled delivery system is constructed as a bone-enhancing factory and loaded with quercetin to treat oxidative stress injury in periodontal tissues. This drug-carrying system made up of nanoscale bioglass microspheres and a light-cured injectable hydrogel, allows effective drug particle loading and cementation in the dynamic and moist periodontal environment. Furthermore, the system demonstrates the ability to stimulate OMSCs osteogenic differentiation in a Per1-dependent manner, which ultimately promotes periodontal bone repair, suggesting that this system has potential for clinical periodontal therapy.

Analysis of joint protein expression profile in anterior disc displacement of TMJ with or without OA.

OBJECTIVE: Anterior disc displacement (ADD) is a common clinical issue and may cause osteoarthritis (OA). However, the research of protein changes in synovial fluid as disease development marker and potential treatment clue is still insufficient. MATERIALS AND METHODS: We conducted the high-resolution mass spectrometry (MS) of synovial fluid collected from 60 patients with normal disk position to ADD and ADD with osteoarthritis (OA). The proteins with significant changes among the 3 groups were analyzed by biological information and further validated by in primary rat condyle chondrocytes and OA animal model. RESULTS: FGL2, THBS4, TNC, FN1, OMD etc. were significantly increased in ADD without OA (p < 0.05), which reflected the active extracellular matrix and collagen metabolism. FGFR1, FBLN2, GRB2 etc. were significantly increased in ADD with OA group (p < 0.05), which revealed an association with apoptosis and ferroptosis. Proteins such as P4HB, CBLN4, FHL1, VIM continuously increase in the whole disease progress (p < 0.05). Both the in vitro and in vivo results are consistent with protein changes detected in MS profile. CONCLUSION: This study firstly provides the expression changes of proteins from normal disc condyle relationship toward ADD with OA, which can be selected and studied further as disease progress marker and potential treatment targets.

Bioinspired Nanospheres as Anti-inflammation and Antisenescence Interfacial Biolubricant for Treating Temporomandibular Joint Osteoarthritis.

The development of temporomandibular joint (TMJ) osteoarthritis is highly associated with mechanical overloading, which can result in accelerated cartilage degradation and damage due to increased interfacial friction and the release of inflammatory factors and catabolic enzymes. In the present study, we for the first time developed self-assembled drug-free nanospheres with pharmaceutical-active functions, which could be used as an intra-articularly injected biolubricant for the treatment of TMJ osteoarthritis based on a synergistic therapy of enhanced lubrication, anti-inflammation, and antisenescence. The nanospheres possessed the hydrophobic core of dopamine methacrylamide and the hydrophilic shell of sulfobetaine methacrylate, which formed into spherical aggregates in aqueous solution by specific interactions following reversible addition-fragmentation chain transfer polymerization. The biodegradation test, tribological test, and free radical scavenging test showed that the nanospheres were endowed with physiological stability, lubrication enhancement, and free radical scavenging capability. In addition, the in vitro cell test revealed that the nanospheres alleviated inflammatory and senescent phenotype for inflammation and oxidative stress stimulated chondrocytes. Furthermore, the in vivo animal test indicated that the nanospheres, after intra-articular injection into TMJ with an osteoarthritis environment, effectively protected condylar cartilage and subchondral bone from structural damage and attenuated cartilage matrix degradation and aging. In summary, the self-assembled nanospheres might be used as a promising biolubricant for achieving anti-inflammatory and antisenescent treatment of TMJ osteoarthritis.

A high-resolution route map reveals distinct stages of chondrocyte dedifferentiation for cartilage regeneration.

Articular cartilage damage is a universal health problem. Despite recent progress, chondrocyte dedifferentiation has severely compromised the clinical outcomes of cell-based cartilage regeneration. Loss-of-function changes are frequently observed in chondrocyte expansion and other pathological conditions, but the characteristics and intermediate molecular mechanisms remain unclear. In this study, we demonstrate a time-lapse atlas of chondrocyte dedifferentiation to provide molecular details and informative biomarkers associated with clinical chondrocyte evaluation. We performed various assays, such as single-cell RNA sequencing (scRNA-seq), live-cell metabolic assays, and assays for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq), to develop a biphasic dedifferentiation model consisting of early and late dedifferentiation stages. Early-stage chondrocytes exhibited a glycolytic phenotype with increased expression of genes involved in metabolism and antioxidation, whereas late-stage chondrocytes exhibited ultrastructural changes involving mitochondrial damage and stress-associated chromatin remodeling. Using the chemical inhibitor BTB06584, we revealed that early and late dedifferentiated chondrocytes possessed distinct recovery potentials from functional phenotype loss. Notably, this two-stage transition was also validated in human chondrocytes. An image-based approach was established for clinical use to efficiently predict chondrocyte plasticity using stage-specific biomarkers. Overall, this study lays a foundation to improve the quality of chondrocytes in clinical use and provides deep insights into chondrocyte dedifferentiation.

Pharmaceutical therapeutics for articular regeneration and restoration: state-of-the-art technology for screening small molecular drugs.

Articular cartilage damage caused by sports injury or osteoarthritis (OA) has gained increased attention as a worldwide health burden. Pharmaceutical treatments are considered cost-effective means of promoting cartilage regeneration, but are limited by their inability to generate sufficient functional chondrocytes and modify disease progression. Small molecular chemical compounds are an abundant source of new pharmaceutical therapeutics for cartilage regeneration, as they have advantages in design, fabrication, and application, and, when used in combination, act as powerful tools for manipulating cellular fate. In this review, we present current achievements in the development of small molecular drugs for cartilage regeneration, particularly in the fields of chondrocyte generation and reversion of chondrocyte degenerative phenotypes. Several clinically or preclinically available small molecules, which have been shown to facilitate chondrogenesis, chondrocyte dedifferentiation, and cellular reprogramming, and subsequently ameliorate cartilage degeneration by targeting inflammation, matrix degradation, metabolism, and epigenetics, are summarized. Notably, this review introduces essential parameters for high-throughput screening strategies, including models of different chondrogenic cell sources, phenotype readout methodologies, and transferable advanced systems from other fields. Overall, this review provides new insights into future pharmaceutical therapies for cartilage regeneration.

High-Resolution Dissection of Chemical Reprogramming from Mouse Embryonic Fibroblasts into Fibrocartilaginous Cells.

Articular cartilage injury and degeneration causing pain and loss of quality-of-life has become a serious problem for increasingly aged populations. Given the poor self-renewal of adult human chondrocytes, alternative functional cell sources are needed. Direct reprogramming by small molecules potentially offers an oncogene-free and cost-effective approach to generate chondrocytes, but has yet to be investigated. Here, we directly reprogrammed mouse embryonic fibroblasts into PRG4+ chondrocytes using a 3D system with a chemical cocktail, VCRTc (valproic acid, CHIR98014, Repsox, TTNPB, and celecoxib). Using single-cell transcriptomics, we revealed the inhibition of fibroblast features and activation of chondrogenesis pathways in early reprograming, and the intermediate cellular process resembling cartilage development. The in vivo implantation of chemical-induced chondrocytes at defective articular surfaces promoted defect healing and rescued 63.4% of mechanical function loss. Our approach directly converts fibroblasts into functional cartilaginous cells, and also provides insights into potential pharmacological strategies for future cartilage regeneration.

Ezh2 Ameliorates Osteoarthritis by Activating TNFSF13B.

Epigenetic regulation is highly correlated with osteoarthritis (OA) development, whereas its role and detailed mechanisms remain elusive. In this study, we explored the expression of EZH2, an H3K27me3 transferase, in human OA cartilages and its roles in regulating OA pathogenesis. Here, we found EZH2 was highly expressed in both mice and human OA cartilage samples by using histological analysis and RNA sequencing (RNA-Seq). The medial meniscectomy (MMx) OA model results indicated the conditional knockout of Ezh2 deteriorated OA pathological conditions. Furthermore, we showed the positive role of Ezh2 in cartilage wound healing and inhibition of hypertrophy through activating TNFSF13B, a member of the tumor necrosis factor superfamily. Further, we also indicated that the effect of TNFSF13B, increased by Ezh2, might boost the healing of chondrocytes through increasing the phosphorylation of Akt. Taken together, our results uncovered an EZH2-positive subpopulation existed in OA patients, and that EZH2-TNFSF13B signaling was responsible for regulating chondrocyte healing and hypertrophy. Thus, EZH2 might act as a new potential target for OA diagnosis and treatment. © 2020 American Society for Bone and Mineral Research.

Therapeutic Agents for the Treatment of Temporomandibular Joint Disorders: Progress and Perspective.

Temporomandibular joint disorders (TMD) are a common health condition caused by the structural or functional disorders of masticatory muscles and the temporomandibular joint (TMJ). Abnormal mandibular movement in TMD patients may cause pain, chronic inflammation, and other discomfort, which could be relieved by a variety of drugs through various delivery systems. In this study, we summarized commonly used therapeutic agents in the management of TMD as well as novel bioactive molecules in preclinical stage and clinical trials. The emerging therapy strategies such as novel intra-TMJ delivery systems and implants based on tissue engineering are also discussed. This comprehensive review will strengthen our understanding of pharmacological approaches for TMD therapy.

Exploring the role of Mir204/211 in HNSCC by the combination of bioinformatic analysis of ceRNA and transcription factor regulation.

OBJECTIVES: This study aimed to reveal the regulatory roles of microRNAs in head and neck squamous cell carcinoma (HNSCC) through comprehensive ceRNA, miRNA-transcription factor (TF)-hub gene network and survival analysis. MATERIALS AND METHODS: Expression analysis was performed using the 'edgeR' package based on The Cancer Genome Atlas database. The ceRNA network was screened by intersecting prediction results from miRcode, miRTarBase, miRDB and TargetScan. GSE30784, GSE59102 and GSE107591 from the Gene Expression Omnibus repository were chosen for cross-validation. Hub genes were identified using a protein-protein interaction network constructed by Search Tool for the Retrieval of Interacting Genes. The Transcriptional Regulatory Relationships Unraveled by Sentence-based Text mining (TTRUST) was utilized to map the miRNA-TF-Hub gene network. Patient overall survival was analyzed using the 'survival' package in R. Structural and functional analysis of miR-204/211 was based on miRbase and RNAstructure. RESULTS: A ceRNA network of 178 lncRNAs, 19 miRNAs and 55 mRNAs was generated, and a TF regulatory network with 11 miRNAs, 11 TFs and 18 hub genes was constructed from the 52 hub genes identified through the protein-protein interaction (PPI) network. Survival analysis demonstrated that the dysregulated expression of 11 lncRNAs and 14 mRNAs was highly related to overall survival. Furthermore, miR-204 and miR-211 were significantly involved in the network with identical mature structures, indicating them as key miRNAs in HNSCC. CONCLUSION: This study reveals the comprehensive molecular regulatory networks centralized by miRNAs in HNSCC and uncovers the crucial role of miR-204 and miR-211, which may become potential diagnostic and therapeutic targets.