Previous studies have shown that long-term spermatogonial stem cells (SSCs) have the potential to spontaneously transform into pluripotent stem cells, which is speculated to be related to the tumorigenesis of testicular germ cells, especially when p53 is deficient in SSCs which shows a significant increase in the spontaneous transformation efficiency. Energy metabolism has been proved to be strongly associated with the maintenance and acquisition of pluripotency. Recently, we compared the difference in chromatin accessibility and gene expression profiles between wild-type (p53^+/+) and p53 deficient (p53^-/-) mouse SSCs using the Assay for Targeting Accessible-Chromatin with high-throughput sequencing (ATAC-seq) and transcriptome sequencing (RNA-seq) techniques, and revealed that SMAD3 is a key transcription factor in the transformation of SSCs into pluripotent cells. In addition, we also observed significant changes in the expression levels of many genes related to energy metabolism after p53 deletion. To further reveal the role of p53 in the regulation of pluripotency and energy metabolism, this paper explored the effects and mechanism of p53 deletion on energy metabolism during the pluripotent transformation of SSCs. The results of ATAC-seq and RNA-seq from p53^+/+ and p53^-/- SSCs revealed that gene chromatin accessibility related to positive regulation of glycolysis and electron transfer and ATP synthesis was increased, and the transcription levels of genes encoding key glycolytic enzymes and regulating electron transport-related enzymes were markedly increased. Furthermore, transcription factors SMAD3 and SMAD4 promoted glycolysis and energy homeostasis by binding to the chromatin of the Prkag2 gene which encodes the AMPK subunit. These results suggest that p53 deficiency activates the key enzyme genes of glycolysis in SSCs and enhances the chromatin accessibility of genes associated with glycolysis activation to improve glycolysis activity and promote transformation to pluripotency. Moreover, SMAD3/SMAD4-mediated transcription of the Prkag2 gene ensures the energy demand of cells in the process of pluripotency transformation and maintains cell energy homeostasis by promoting AMPK activity. These results shed light on the importance of the crosstalk between energy metabolism and stem cell pluripotency transformation, which might be helpful for clinical research of gonadal tumors.
Animals ; Mice ; AMP-Activated Protein Kinases ; Chromatin ; Energy Metabolism ; Gene Deletion ; Stem Cells ; Tumor Suppressor Protein p53/genetics* ; Spermatogonia/cytology* ; Male

As a group of nonspecific inflammatory diseases affecting the intestine, inflammatory bowel disease (IBD) exhibits the characteristics of chronic recurring inflammation, and was proven to be increasing in incidence (Kaplan, 2015). IBD induced by genetic background, environmental changes, immune functions, microbial composition, and toxin exposures (Sasson et al., 2021) primarily includes ulcerative colitis (UC) and Crohn's disease (CD) with complicated clinical symptoms featured by abdominal pain, diarrhea, and even blood in stools (Fan et al., 2021; Huang et al., 2021). UC is mainly limited to the rectum and the colon, while CD usually impacts the terminal ileum and colon in a discontinuous manner (Ordás et al., 2012; Panés and Rimola, 2017). In recent years, many studies have suggested the lack of effective measures in the diagnosis and treatment of IBD, prompting an urgent need for new strategies to understand the mechanisms of and offer promising therapies for IBD.
Chronic Disease ; Colitis, Ulcerative/therapy* ; Crohn Disease/epidemiology* ; Diarrhea ; Homeodomain Proteins ; Humans ; Inflammatory Bowel Diseases ; Mesenchymal Stem Cells/cytology* ; MicroRNAs ; RNA, Long Noncoding ; Recurrence ; Umbilical Cord/cytology*

Aging of craniofacial skeleton significantly impairs the repair and regeneration of trauma-induced bony defects, and complicates dental treatment outcomes. Age-related alveolar bone loss could be attributed to decreased progenitor pool through senescence, imbalance in bone metabolism and bone-fat ratio. Mesenchymal stem cells isolated from oral bones (OMSCs) have distinct lineage propensities and characteristics compared to MSCs from long bones, and are more suited for craniofacial regeneration. However, the effect of epigenetic modifications regulating OMSC differentiation and senescence in aging has not yet been investigated. In this study, we found that the histone demethylase KDM4B plays an essential role in regulating the osteogenesis of OMSCs and oral bone aging. Loss of KDM4B in OMSCs leads to inhibition of osteogenesis. Moreover, KDM4B loss promoted adipogenesis and OMSC senescence which further impairs bone-fat balance in the mandible. Together, our data suggest that KDM4B may underpin the molecular mechanisms of OMSC fate determination and alveolar bone homeostasis in skeletal aging, and present as a promising therapeutic target for addressing craniofacial skeletal defects associated with age-related deteriorations.
Aging ; Cell Differentiation ; Facial Bones/physiology* ; Humans ; Jumonji Domain-Containing Histone Demethylases/genetics* ; Mesenchymal Stem Cells/cytology* ; Osteogenesis ; Osteoporosis

ABSTRACT The use of tooth-derived material as a scaffold has gained attention recently due to its ease of availability and bioactive properties. Hence, the objective of this study was to determine in vitro interaction of human gingival mesenchymal stem cells (hGMSCs) with human demineralised teeth matrix (hDTM) on osteogenic potential with or without osteogenic inducers. The hGMSCs were established and characterised on their morphology, proliferation, population doubling time (PDT), viability, colony-forming ability, expression of cell surface markers and adipogenic differentiation. Further, the effect of hDTM on the biocompatibility and osteogenic differentiation ability of hGMSCs was evaluated. The hGMSCs displayed a fibroblast-like appearance and exhibited a greater proliferative activity. The cells showed > 91% viability, and PDT varied between 39.34 hours and 62.59 hours. Further, hGMSCs indicated their propensity to form clusters/ colonies, and expressed the markers, such as CD29, CD44, CD73 and CD90, but were negative for CD34 and CD45. When treated with adipogenic induction medium, hGMSCs were able to exhibit the formation of neutral lipid vacuoles. The hGMSCs cultured with hDTM did not show any cytotoxic changes including morphology and viability. Mineralisation of calcium nodules was observed in hGMSCs when cultured in osteogenic induction (OI) medium as an indication of osteogenesis. hGMSCs when cultured with hDTM confirmed the presence of a mineralised matrix. Further, when the cells were cultured with hDTM along with OI, they showed slightly enhanced differentiation into osteocytes. In conclusion, hGMSCs were shown to be biocompatible with hDTM, and demonstrated their enhanced osteogenic potential in the presence of hDTM and osteogenic supplements.
Mesenchymal Stem Cells ; Dental Pulp--cytology ; Dentin

ABSTRACT The use of tooth-derived material as a scaffold has gained attention recently due to its ease of availability and bioactive properties. Hence, the objective of this study was to determine in vitro interaction of human gingival mesenchymal stem cells (hGMSCs) with human demineralised teeth matrix (hDTM) on osteogenic potential with or without osteogenic inducers. The hGMSCs were established and characterised on their morphology, proliferation, population doubling time (PDT), viability, colony-forming ability, expression of cell surface markers and adipogenic differentiation. Further, the effect of hDTM on the biocompatibility and osteogenic differentiation ability of hGMSCs was evaluated. The hGMSCs displayed a fibroblast-like appearance and exhibited a greater proliferative activity. The cells showed > 91% viability, and PDT varied between 39.34 hours and 62.59 hours. Further, hGMSCs indicated their propensity to form clusters/ colonies, and expressed the markers, such as CD29, CD44, CD73 and CD90, but were negative for CD34 and CD45. When treated with adipogenic induction medium, hGMSCs were able to exhibit the formation of neutral lipid vacuoles. The hGMSCs cultured with hDTM did not show any cytotoxic changes including morphology and viability. Mineralisation of calcium nodules was observed in hGMSCs when cultured in osteogenic induction (OI) medium as an indication of osteogenesis. hGMSCs when cultured with hDTM confirmed the presence of a mineralised matrix. Further, when the cells were cultured with hDTM along with OI, they showed slightly enhanced differentiation into osteocytes. In conclusion, hGMSCs were shown to be biocompatible with hDTM, and demonstrated their enhanced osteogenic potential in the presence of hDTM and osteogenic supplements.
Mesenchymal Stem Cells ; Dental Pulp--cytology ; Dentin

Chemically defined medium is widely used for culturing mouse embryonic stem cells (mESCs), in which N2B27 works as a substitution for serum, and GSK3β and MEK inhibitors (2i) help to promote ground-state pluripotency. However, recent studies suggested that MEKi might cause irreversible defects that compromise the developmental potential of mESCs. Here, we demonstrated the deficient bone morphogenetic protein (BMP) signal in the chemically defined condition is one of the main causes for the impaired pluripotency. Mechanistically, activating the BMP signal pathway by BMP4 could safeguard the chromosomal integrity and proliferation capacity of mESCs through regulating downstream targets Ube2s and Chmp4b. More importantly, BMP4 promotes a distinct in vivo developmental potential and a long-term pluripotency preservation. Besides, the pluripotent improvements driven by BMP4 are superior to those by attenuating MEK suppression. Taken together, our study shows appropriate activation of BMP signal is essential for regulating functional pluripotency and reveals that BMP4 should be applied in the serum-free culture system.
Animals ; Bone Morphogenetic Protein 4/metabolism* ; Cell Differentiation ; Chromosomal Instability ; Endosomal Sorting Complexes Required for Transport ; Mice ; Mitogen-Activated Protein Kinase Kinases/metabolism* ; Mouse Embryonic Stem Cells/cytology* ; Pluripotent Stem Cells/cytology* ; Signal Transduction ; Ubiquitin-Conjugating Enzymes

OBJECTIVE: To compare the mRNA level of cell proliferation-related genes Twist1, SIRT1, FGF2 and TGF-β3 in placenta mesenchymal stem cells (PA-MSCs), umbilical cord mensenchymals (UC-MSCs) and dental pulp mesenchymal stem cells (DP-MSCs). METHODS: The morphology of various passages of PA-MSCs, UC-MSCs and DP-MSCs were observed by microscopy. Proliferation and promoting ability of the three cell lines were detected with the MTT method. Real-time PCR (RT-PCR) was used to determine the mRNA levels of Twist1, SIRT1, FGF2, TGF-β3. RESULTS: The morphology of UC-MSCs and DP-MSCs was different from that of PA-MSCs. Proliferation ability and promoting ability of the PA-MSCs was superior to that of UC-MSCs and DP-MSCs. In PA-MSCs, expression level of Twist1 and TGF-β3 was the highest and FGF2 was the lowest. SIRT1 was highly expressed in UC-MSCs. With the cell subcultured, different expression levels of Twist1, SIRT1, FGF2, TGF-β3 was observed in PA-MSCs, UC-MSCs and DP-MSCs. CONCLUSION Up-regulated expression of the Twist1, SIRT1 and TGF-β3 genes can promote proliferation of PA-MSCs, UC-MSCs and DP-MSCs, whilst TGF-β3 may inhibit these. The regulatory effect of Twist1, SIRT1, FGF2 and TGF-β3 genes on PA-MSCs, UC-MSCs and DP-MSCs are different.
Cell Differentiation ; Cell Proliferation/genetics* ; Cells, Cultured ; Dental Pulp/cytology* ; Female ; Fibroblast Growth Factor 2/genetics* ; Humans ; Mesenchymal Stem Cells/cytology* ; Nuclear Proteins/genetics* ; Placenta/cytology* ; Pregnancy ; Sirtuin 1/genetics* ; Transforming Growth Factor beta3/genetics* ; Twist-Related Protein 1/genetics* ; Umbilical Cord/cytology*

OBJECTIVES: This study aims to explore the effect and molecular mechanism of long non-coding RNA (lncRNA) potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (KCNQ1OT1) on proliferation and osteogenic differentiation in human periodontal ligament stem cells (hPDLSCs). METHODS: The hPDLSCs of normal periodontal tissues were isolated and cultured. The mineralized solution induced the osteoblast differentiation of hPDLSCs. The down-regulation of lncRNA KCNQ1OT1, the overexpression of anti-miR-24-3p on the proliferation and the levels of osteocalcin (OCN), osteopontin (OPN) and alkaline phosphatase (ALP) of hPDLSCs were investigated. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the levels of lncRNA KCNQ1OT1, miR-24-3p, OCN, OPN, and ALP. Methyl thiazolyl tetrazolium (MTT) method was used to detect cell viability and activity. Cell proliferation was evaluated by MTT. Western blot was used to detect protein expression. The targeted relationship between lncRNA KCNQ1OT1 and miR-24-3p was detected by double-luciferase experiment. RESULTS: The expression level of lncRNA KCNQ1OT1 increased, and that of miR-24-3p decreased during the osteogenesis of hPDLSCs ( CONCLUSIONS Down-regulation of lncRNA KCNQ1OT1 inhibited the proliferation and osteogenic differentiation of hPDLSCs by targeting the up-regulated expression of miR-24-3p.
Cell Differentiation ; Cell Proliferation ; Humans ; MicroRNAs/genetics* ; Osteogenesis ; Periodontal Ligament/cytology* ; Potassium ; Potassium Channels, Voltage-Gated ; RNA, Long Noncoding/genetics* ; Stem Cells/cytology*

Humans with chronic psychological stress are prone to develop multiple disorders of body function including impairment of immune system. Chronic psychological stress has been reported to have negative effects on body immune system. However, the underlying mechanisms have not been clearly demonstrated. All immune cells are derived from hematopoietic stem cells (HSC) in the bone marrow, including myeloid cells which comprise the innate immunity as a pivotal component. In this study, to explore the effects of chronic psychological stress on HSC and myeloid cells, different repeated restraint sessions were applied, including long-term mild restraint in which mice were individually subjected to a 2 h restraint session twice daily (morning and afternoon/between 9:00 and 17:00) for 4 weeks, and short-term vigorous restraint in which mice were individually subjected to a 16 h restraint session (from 17:00 to 9:00 next day) for 5 days. At the end of restraint, mice were sacrificed and the total cell numbers in the bone marrow and peripheral blood were measured by cell counting. The proportions and absolute numbers of HSC (LinCD117Sca1CD150CD48) and myeloid cells (CD11bLy6C) were detected by fluorescence activated cell sorting (FACS) analysis. Proliferation of HSC was measured by BrdU incorporation assay. The results indicated that the absolute number of HSC was increased upon long-term mild restraint, but was decreased upon short-term vigorous restraint with impaired proliferation. Both long-term mild restraint and short-term vigorous restraint led to the accumulation of CD11bLy6C cells in the bone marrow as well as in the peripheral blood, as indicated by the absolute cell numbers. Taken together, long-term chronic stress led to increased ratio and absolute number of HSC in mice, while short-term stress had opposite effects, which suggests that stress-induced accumulation of CD11bLy6C myeloid cells might not result from increased number of HSC.
Animals ; Antigens, Ly ; metabolism ; Bone Marrow Cells ; cytology ; CD11b Antigen ; metabolism ; Cell Proliferation ; Hematopoietic Stem Cells ; cytology ; Mice ; Mice, Inbred C57BL ; Restraint, Physical ; Stress, Psychological

At present, SARS-CoV-2 is raging, and novel coronavirus pneumonia (COVID-19) has caused more than 35 million confirmed patients and more than 500 000 cases death, which seriously endanger human health, socioeconomic development, as well as global medical and public health systems. COVID-19 is highly contagious, has a long incubation period, and causes many death cases due to lack of effective specific treatment. Mesenchymal stem cells have powerful anti-inflammatory and immunoregulatory functions, and can effectively reduce the cytokine storm caused by coronavirus in patients, and improve the pulmonary fibrosis of patients, promote the repair of damaged lung tissue, and reduce the mortality. Currently, a number of related clinical trials of mesenchymal stem cell treatment of COVID-19 have been conducted, and have confirmed the safety and efficacy, suggesting a good clinical application prospect. While progress has been made in mesenchymal stem cell therapy for COVID-19, we should also catch sight of the problems and challenges faced by mesenchymal stem cell clinical trials under severe epidemic situation, including clinical trials design, stem cell quality management, and ethics in treatment. Only by paying attention to these can we guarantee the safe and effective development of mesenchymal stem cell clinical trials in the treatment of COVID-19.
Betacoronavirus ; COVID-19 ; Clinical Trials as Topic ; Coronavirus Infections/therapy* ; Humans ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stem Cells/cytology* ; Pandemics ; Pneumonia, Viral/therapy* ; SARS-CoV-2