Beyond energy production, nutrient metabolism plays a crucial role in stem cell lineage determination. Changes in metabolism based on nutrient availability and dietary habits impact stem cell identity. Evidence suggests a strong link between metabolism and epigenetic mechanisms occurring during embryonic development and later life of offspring. Metabolism regulates epigenetic mechanisms such as modifications of DNA, histones, and microRNAs. In turn, these epigenetic mechanisms regulate metabolic pathways to modify the metabolome. One-carbon metabolism (OCM) is a crucial metabolic process involving transfer of the methyl groups leading to regulation of multiple cellular activities. OCM cycles and its related micronutrients are ubiquitously present in stem cells and feed into the epigenetic mechanisms. In this review, we briefly introduce the OCM process and involved micronutrients and discuss OCM-associated epigenetic modifications, including DNA methylation, histone modification, and microRNAs. We further consider the underlying OCM-mediated link between nutrition and epigenetic modifications in embryonic development.

The Hedgehog (Hh) signaling pathway orchestrates its influence through a dynamic interplay of Hh proteins, the cell surface receptor Ptch1, Smo, and Gli transcription factors, contributing to a myriad of developmental events. Indian Hedgehog (Ihh) and Gli zinc finger transcription factor 1 (Gli1) play crucial roles in developmental regulation within the Hh signaling pathway. Ihh regulates chondrocyte proliferation, differentiation, and bone formation, impacting the development of cranial bones, cartilage, and the temporomandibular joint (TMJ). Losing Ihh results in cranial bone malformation, decreased ossification, and affects the formation of cranial base cartilage unions, TMJ condyles, and joint discs. Gli1 is predominantly expressed during early craniofacial development, and Gli1+ cells are identified as the primary mesenchymal stem cells (MSCs) for craniofacial bones, crucial for cell differentiation and morphogenesis. Additionally, a complex mutual regulatory mechanism exists between Gli1 and Ihh, ensuring the normal function of the Hh signaling pathway by directly or indirectly regulating each other's expression levels. And the interaction between Ihh and Gli1 significantly impacts the normal development of craniofacial tissues.This review summarizes the pivotal roles of Gli1 and Ihh in the intricate landscape of mammalian craniofacial development, and outlines the molecular regulatory mechanisms and intricate interactions governing the growth of bone and cartilage exhibited by Gli1 and Ihh, which Provides new insights into potential therapeutic strategies for related diseases or researches of tissue regeneration.

As a novel research hotspot in tissue regeneration, dental-derived mesenchymal stromal cells (MSCs) are famous for their accessibility, multipotent differentiation ability, and high proliferation. However, cellular heterogeneity is a major obstacle to the clinical application of dental-derived MSCs. Here, we reviewed the heterogeneity of dental-derived MSCs firstly and then discussed the key markers and epigenetic modifications related to the proliferation, differentiation, immunomodulation, and aging of dental-derived MSCs. These messages help to control the composition and function of dental-derived MSCs and thus accelerate the translation of cell therapy into clinical practice.

Mesenchymal stem cell (MSC)-based therapies for articular cartilage regeneration are effective mostly due to paracrine signals mediated by extracellular vesicles, especially small extracellular vesicles (sEV). However, it is unknown whether dental follicle cell-derived sEV (DFC-sEV) affect cartilage regeneration in temporomandibular joint osteoarthritis (TMJ-OA). In this study, the effects of DFC-sEV on IL-1β-induced mandibular condylar chondrocytes (MCCs) were determined using CCK8 assays, scratch assays, flow cytometry, and Western blot analysis of matrix synthesis and catabolic proteins. Furthermore, we used an abnormal occlusion-induced rat model and intra-articular injection of DFC-sEV, the pathological changes of which were observed by HE staining, safranin O staining, immunohistochemistry, and micro-CT analysis of subchondral bone loss. Gene set enrichment analysis (GSEA) was used to determine the related mechanism involved in the effect of DFC-sEV. Immunofluorescence analysis and Western blotting were used to evaluate the expression of HIF-1α, HIF-2α, MMP13, and VEGF in MCCs. Then, lentivirus-induced Epas1 overexpression and Western blot analysis of the downstream regulators of HIF-2α were performed. We found that DFC-sEV promoted MCCs proliferation and migration and protected against cartilage matrix destruction induced by IL-1β. In addition, DFC-sEV prevented cartilage destruction in an abnormal occlusion rat model. Furthermore, we found that DFC-sEV reduced the expression of HIF-1α and HIF-2α in vitro and in vivo and decreased the downstream regulators of HIF-2α, including MMP13 and VEGF. Our study indicated that DFC-sEV attenuated TMJ cartilage damage in vitro and in vivo, which might be involved in the regulation of HIF-2α.

Background: Sappanwood is widely used in the prevention and treatment in diseases due to its ability to seal blood vessels, dissipate stasis, and relieve pain. Important monomer components of sappanwood, Protosappanin A (PA) and Protosappanin B (PB) have anti-tumour and antimicrobial medicinal properties. This study investigated the anti-inflammatory and osteogenic differentiation effects of a crude extract of Sappanwood (ESP), PA and PB against periodontitis in periodontal ligament stem cells (PDLSCs). Methods: Oil Red O staining was used to assess the ability of adipocytes to differentiate. Alizarin Red staining was used to assess the capacity to differentiate into osteoblasts. Third-passage PDLSCs were grown in either basic medium alone or basic media with varying doses of ESP (0.0625 mg/mL, 0.03125 mg/mL and 0.125 mg/mL), PA and PB (2.5 µM, 5 µM, 10 µM). The CCK-8 assay was used to measure cell proliferation. Real Time PCR (RT-qPCR) and Enzyme-Linked Immunosorbnent Assay (ELISA) assay were used to measure gene expression. The capacity to differentiate into osteoblasts was evaluated using Alizarin Red staining, and Alkaline Phosphatase (ALP) staining and activity. Results: The development of lipid droplets and mineralized nodules was examined using Oil Red O staining and Alizarin Red staining. Flow cytometry revealed that PDLSCs were CD29 (98.23%) and CD44 (98.81%) positive, but CD34 (0.16%) and CD45 (0.09%) negative. CCK-8 assay showed that ESP at three concentrations (0.03125 mg/mL, 0.0625 mg/mL and 0.125 mg/mL) and 2.5 µM, 5 µM and 10 µM PA and PB had no cytotoxicity at 5 and 7 days (p < 0.05). qRT-PCR and ELISA assay indicated that ESP, PA and PB downregulated the inflammatory cytokines IL-8, IL-6, IL-1β, IL-10 and IL-4 and elevated the mRNA expression of osteogenesis cytokines RUNX2 , OSX and OCN in PDLSCs (p < 0.05). Alizarin red staining, and ALP staining and activity showed that ESP, PA and PB increased mineralized nodules and the ALP content of in PDLSCs (p < 0.05). Conclusions: ESP, PA and PB can reduce the inflammatory response and amplify the osteogenic differentiation of PDLSCs. Therefore, ESP, PA and PB may have potential pharmacological effects in controlling the progression of periodontitis and promoting periodontal tissue regeneration.