Dental mesenchymal stem cells (DMSCs) are pivotal for tooth development and periodontal tissue health and play an important role in tissue engineering and regenerative medicine because of their multidirectional differentiation potential and self-renewal ability. The cellular microenvironment regulates the fate of stem cells and can be modified using various optimization techniques. These methods can influence the cellular microenvironment, activate disparate signaling pathways, and induce different biological effects. "Epigenetic regulation" refers to the process of influencing gene expression and regulating cell fate without altering DNA sequences, such as histone methylation. Histone methylation modifications regulate pivotal transcription factors governing DMSCs differentiation into osteo-/odontogenic lineages. The most important sites of histone methylation in tooth organization were found to be H3K4, H3K9, and H3K27. Histone methylation affects gene expression and regulates stem cell differentiation by maintaining a delicate balance between major trimethylation sites, generating distinct chromatin structures associated with specific downstream transcriptional states. Several crucial signaling pathways associated with osteogenic differentiation are susceptible to modulation via histone methylation modifications. A deeper understanding of the regulatory mechanisms governing histone methylation modifications in osteo-/odontogenic differentiation and immune-inflammatory responses of DMSCs will facilitate further investigation of the epigenetic regulation of histone methylation in DMSC-mediated tissue regeneration and inflammation. Here is a concise overview of the pivotal functions of epigenetic histone methylation at H3K4, H3K9, and H3K27 in the regulation of osteo-/odontogenic differentiation and renewal of DMSCs in both non-inflammatory and inflammatory microenvironments. This review summarizes the current research on these processes in the context of tissue regeneration and therapeutic interventions.
Mesenchymal Stem Cells/physiology* ; Humans ; Osteogenesis/genetics* ; Histones/metabolism* ; Cell Differentiation/physiology* ; Methylation ; Odontogenesis/genetics* ; Epigenesis, Genetic

Tissue interactions play a crucial role in tooth development. Notably, extracellular vesicle-mediated interactions between the mandible and tooth germ are considered essential. Here, we revealed that mandible extracellular vesicles could modulate the proliferation and differentiation of dental mesenchymal cells by regulating the histone demethylase KDM2B. Further investigation showed that mandible derived extracellular vesicles could deliver miR-206 to KDM2B, thereby regulating tooth development. An animal study demonstrated that the miR-206/KDM2B pathway affected tooth morphogenesis and mineralization after eight weeks of subcutaneous transplantation in nude mice. In conclusion, this study suggested that the mandible played a critical role in tooth morphogenesis and mineralization, which could be a potential therapeutic target for abnormal tooth development and an alternative model for tooth regeneration.
Animals ; Extracellular Vesicles/metabolism* ; Jumonji Domain-Containing Histone Demethylases/metabolism* ; Swine ; MicroRNAs/metabolism* ; Mandible ; Mice, Nude ; Odontogenesis/physiology* ; Swine, Miniature ; Mice ; Cell Differentiation ; Cell Proliferation

Extracellular vesicles (EVs), defined as cell-secreted nanoscale vesicles that carry bioactive molecules, have emerged as a promising therapeutic strategy in tumor and tissue regeneration. Their potential in repairing intervertebral disc degeneration (IDD) through multidimensional regulatory mechanisms is a rapidly advancing field of research. This paper provided an overview of the mechanisms of EVs in IDD repair, thoroughly reviewed recent literature on EVs for IDD, domestically and internationally, and summarized their therapeutic mechanisms. In IDD repair, EVs could act through different mechanisms at the molecular, cellular, and tissue levels. At the molecular level, EVs could treat IDD by inhibiting inflammatory reactions, suppressing oxidative stress, and regulating the synthesis and decomposition of extracellular matrix. At the cellular level, EVs could treat IDD by inhibiting cellular pyroptosis, ferroptosis, and apoptosis and promoting cell proliferation and differentiation. At the tissue level, EVs could treat IDD by inhibiting neovascularization. EVs have a strong potential for clinical application in the treatment of IDD and deserve more profound study.
Extracellular Vesicles/physiology* ; Humans ; Intervertebral Disc Degeneration/therapy* ; Apoptosis ; Cell Proliferation ; Oxidative Stress ; Cell Differentiation ; Extracellular Matrix/metabolism* ; Animals ; Pyroptosis

BACKGROUND: Fibrosis of the connective tissue in the vaginal wall predominates in pelvic organ prolapse (POP), which is characterized by excessive fibroblast-to-myofibroblast differentiation and abnormal deposition of the extracellular matrix (ECM). Our study aimed to investigate the effect of ECM stiffness on vaginal fibroblasts and to explore the role of methyltransferase 3 (METTL3) in the development of POP. METHODS: Polyacrylamide hydrogels were applied to create an ECM microenvironment with variable stiffness to evaluate the effects of ECM stiffness on the proliferation, differentiation, and expression of ECM components in vaginal fibroblasts. METTL3 small interfering RNA and an overexpression vector were transfected into vaginal fibroblasts to evaluate the effects of METTL3 silencing and overexpression on matrix stiffness-induced vaginal fibroblast-to-myofibroblast differentiation and abnormal modulation of the ECM. Both procedures were detected by 5-ethynyl-2'-deoxyuridine (EdU) staining, Western blotting (WB), quantitative real-time polymerase chain reaction (RT-qPCR), and immunofluorescence (IF). RESULTS: Vaginal fibroblasts from POP patients exhibited increased proliferation ability, increased expression of α-smooth muscle actin (α-SMA), decreased expression of collagen I/III, and significantly decreased expression of tissue inhibitors of matrix metalloproteinases (TIMPs) in the stiff matrix ( P <0.05). Compared with those from non-POP patients, vaginal wall tissues from POP patients demonstrated a significant increase in METTL3 content ( P <0.05). However, silencing METTL3 expression in vaginal fibroblasts with high ECM stiffness resulted in decreased proliferation ability, decreased α-SMA expression, an increased ratio of collagen I/III, and increased TIMP1 and TIMP2 expression. Conversely, METTL3 overexpression significantly promoted the process of increased proliferation ability, increased α-SMA expression, decreased ratio of collagen I/III and decreased TIMP1 and TIMP2 expression in the soft matrix ( P <0.05). CONCLUSIONS Elevated ECM stiffness can promote excessive proliferation, differentiation, and abnormal ECM modulation, and the expression of METTL3 plays an important role in alleviating or aggravating matrix stiffness-induced vaginal fibroblast-to-myofibroblast differentiation and abnormal ECM modulation.
Humans ; Female ; Extracellular Matrix/metabolism* ; Cell Differentiation/genetics* ; Methyltransferases/metabolism* ; Pelvic Organ Prolapse/pathology* ; Fibroblasts/metabolism* ; Myofibroblasts/metabolism* ; Vagina/metabolism* ; Cell Proliferation/physiology* ; Cells, Cultured ; Middle Aged

Mitochondrial metabolism is crucial for providing energy and heme precursors during erythroid development. Oxoglutarate dehydrogenase complex (OGDC) is a key enzyme in the mitochondrial tricarboxylic acid (TCA) cycle, and its level gradually increases during erythroid development, indicating its significant role in erythroid development. The aim of the present study was to explore the role and mechanism of OGDC in erythroid development. In this study, we treated erythroid progenitor cells with CPI-613, a novel lipoic acid analog that competitively inhibits OGDC. The results showed that CPI-613 inhibited erythropoietin (EPO)-induced differentiation and enucleation of human CD34⁺ hematopoietic stem cells into erythroid cells, suppressed cell proliferation, and induced apoptosis. The results of in vivo experiments showed that CPI-613 also hindered the recovery of mice from acute hemolytic anemia. Further mechanism research results showed that CPI-613 increased reactive oxygen species (ROS) in erythroid progenitor cells, inhibited mitochondrial respiration, caused mitochondrial damage, and suppressed heme synthesis, thereby inhibiting erythroid differentiation. Clinical research results showed that oxoglutarate dehydrogenase (OGDH) protein expression levels were up-regulated in bone marrow cells of polycythemia vera (PV) patients. Treatment with CPI-613 significantly inhibited the excessive proliferation and differentiation of erythroid progenitor cells of the PV patients. These findings demonstrates the critical role of OGDC in normal erythroid development, suggesting that inhibiting its activity could be a novel therapeutic strategy for treating PV.
Animals ; Humans ; Mitochondria/metabolism* ; Mice ; Ketoglutarate Dehydrogenase Complex/physiology* ; Cell Differentiation/drug effects* ; Cells, Cultured ; Erythropoiesis/drug effects* ; Reactive Oxygen Species/metabolism* ; Cell Proliferation/drug effects* ; Erythroid Precursor Cells/cytology* ; Apoptosis/drug effects* ; Thioctic Acid/pharmacology* ; Caprylates ; Sulfides

Cardiovascular diseases are the leading cause of mortality, posing a significant threat to human health due to the high incidence rate. Atherosclerosis, a chronic inflammatory disease, serves as the primary pathological basis for most such conditions. The incidence of atherosclerosis continues to rise, but its pathogenesis has not been fully elucidated. As an important member of the small GTPase superfamily, Ras-association proximate 1 (Rap1) is an important molecular switch involved in the regulation of multiple physiological functions including cell differentiation, proliferation, and adhesion. Rap1 achieves the utility of the molecular switch by cycling between Rap1-GTP and Rap1-GDP. Rap1 may influence the occurrence and development of atherosclerosis in a cell-specific manner. This article summarizes the potential role and mechanism of Rap1 in the progression of atherosclerosis in different cells, aiming to provide new therapeutic targets and strategies for clinical intervention.
Humans ; Atherosclerosis/metabolism* ; rap1 GTP-Binding Proteins/physiology* ; Animals ; Cell Differentiation ; Cell Adhesion ; Cell Proliferation

Steroid-induced osteonecrosis of femoral head (SONFH) is a disease characterized by femoral head collapse and local pain caused by excessive use of glucocorticoids. Peroxisome proliferator-activated receptor-γ (PPARγ) is mainly expressed in adipose tissue. Wnt/β-catenin, AMPK and other related signaling pathways play an important role in regulating adipocyte differentiation, fatty acid uptake and storage. Bone marrow mesenchymal cells (BMSCs) have the ability to differentiate into adipocytes or osteoblasts, and the use of hormones upregulates PPARγ expression, resulting in BMSCs biased towards adipogenic differentiation. The increase of adipocytes affects the blood supply and metabolism of the femoral head, and the decrease of osteoblasts leads to the loss of trabecular bone, which eventually leads to partial or total ischemic necrosis and collapse of the femoral head. MicroRNAs (miRNAs) are a class of short non-coding RNAs that regulate gene expression by inhibiting the transcription or translation of target genes, thereby affecting cell function and disease progression. Studies have shown that miRNAs affect the progression of SONFH by regulating PPARγ lipid metabolism-related signaling pathways. Therefore, it may be an accurate and feasible SONFH treatment strategy to regulate adipogenic-osteoblast differentiation in BMSCs by targeted intervention of miRNA differential expression to improve lipid metabolism. In this paper, the miRNA-mediated PPARγ-related signaling pathways were classified and summarized to clarify their effects on lipid metabolism in SONFH, providing a theoretical reference for miRNA targeted therapy of SONFH, and then providing scientific evidence for SONFH precision medicine.
MicroRNAs/physiology* ; PPAR gamma/metabolism* ; Femur Head Necrosis/metabolism* ; Humans ; Signal Transduction/physiology* ; Lipid Metabolism/physiology* ; Animals ; Cell Differentiation ; Mesenchymal Stem Cells/cytology* ; Glucocorticoids/adverse effects*

Transcription factor PU.1, as a core member of the ETS family, plays a pivotal role in the multi-lineage differentiation of hematopoietic stem cells, particularly in the regulation of erythroid differentiation. PU.1 orchestrates the process of hematopoietic stem cell differentiation towards erythroid cells by modulating the transcription of lineage-determining factors and interacting with other key transcription factors in a fine-tuned manner. PU.1 plays an irreplaceable role in the development and function of red blood cells, with its abnormal expression closely related to the occurrence and progression of various blood diseases, including leukemia, myelodysplastic syndromes, and various types of anemia. This article comprehensively analyzes the functional roles and molecular mechanisms of PU.1 in various stages of erythroid differentiation, as well as its potential roles in related blood diseases. This review not only deepens our understanding of the mechanism by which PU.1 regulates erythroid differentiation, but also provides theoretical grounds for blood disease therapies based on PU.1.
Humans ; Proto-Oncogene Proteins/genetics* ; Trans-Activators/genetics* ; Cell Differentiation/physiology* ; Hematologic Diseases/physiopathology* ; Erythroid Cells/cytology* ; Animals ; Erythropoiesis/physiology*

Infertility has become one of the most serious diseases worldwide, and 50% of this disease can be attributed to male-related factors. Spermatogenesis, by definition, is a complex process by which spermatogonial stem cells (SSCs) self-renew to maintain stem cell population within the testes and differentiate into mature spermatids. It is of great significance to uncover gene regulation and signaling pathways that are involved in the fate determinations of SSCs with aims to better understand molecular mechanisms underlying human spermatogenesis and identify novel targets for gene therapy of male infertility. Significant achievement has recently been made in demonstrating the signaling molecules and pathways mediating the fate decisions of mammalian SSCs. In this review, we address key gene regulation and crucial signaling transduction pathways in controlling the self-renewal, differentiation, and apoptosis of SSCs, and we illustrate the networks of genes and signaling pathways in SSC fate determinations. We also highlight perspectives and future directions in SSC regulation by genes and their signaling pathways. This review could provide novel insights into the genetic regulation of normal and abnormal spermatogenesis and offer molecular targets to develop new approaches for gene therapy of male infertility.
Humans ; Male ; Signal Transduction/physiology* ; Apoptosis/physiology* ; Spermatogenesis/physiology* ; Cell Differentiation ; Adult Germline Stem Cells/physiology* ; Spermatogonia/cytology* ; Gene Expression Regulation ; Animals ; Infertility, Male/genetics* ; Cell Self Renewal/genetics*

Mouse spermatogenesis entails the maintenance and self-renewal of spermatogonial stem cells (SSCs), which require a complex web-like signaling network transduced by various cytokines. Although brain-derived neurotrophic factor (BDNF) is expressed in Sertoli cells in the testis, and its receptor tropomyosin receptor kinase B (TrkB) is expressed in the spermatogonial population containing SSCs, potential functions of BDNF for spermatogenesis have not been uncovered. Here, we generate BDNF conditional knockout mice and find that BDNF is dispensable for in vivo spermatogenesis and fertility. However, in vitro , we reveal that BDNF -deficient germline stem cells (GSCs) exhibit growth potential not only in the absence of glial cell line-derived neurotrophic factor (GDNF), a master regulator for GSC proliferation, but also in the absence of other factors, including epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and insulin. GSCs grown without these factors are prone to differentiation, yet they maintain expression of promyelocytic leukemia zinc finger ( Plzf ), an undifferentiated spermatogonial marker. Inhibition of phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK), and Src pathways all interfere with the growth of BDNF-deficient GSCs. Thus, our findings suggest a role for BDNF in maintaining the undifferentiated state of spermatogonia, particularly in situations where there is a shortage of growth factors.
Animals ; Male ; Brain-Derived Neurotrophic Factor/genetics* ; Spermatogonia/cytology* ; Mice ; Spermatogenesis/genetics* ; Mice, Knockout ; Cell Differentiation ; Glial Cell Line-Derived Neurotrophic Factor/genetics* ; Promyelocytic Leukemia Zinc Finger Protein/genetics* ; Cell Survival/physiology* ; Signal Transduction/physiology* ; Cell Proliferation/physiology*