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

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

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

Once pulp necrosis or apical periodontitis occurs on immature teeth, the weak root and open root apex are challenging to clinicians. Berberine (BBR) is a potential medicine for bone disorders, therefore, we proposed to apply BBR in root canals to enhance root repair in immature teeth. An in vivo model of immature teeth with apical periodontitis was established in rats, and root canals were filled with BBR, calcium hydroxide or sterilized saline for 3 weeks. The shape of the roots was analyzed by micro-computed tomography and histological staining. In vitro, BBR was introduced into stem cells from apical papilla (SCAPs). Osteogenic differentiation of stem cells from apical papilla was investigated by alkaline phosphatase activity, mineralization ability, and gene expression of osteogenic makers. The signaling pathway, which regulated the osteogenesis of SCAPs was evaluated by quantitative real time PCR, Western blot analysis, and immunofluorescence. In rats treated with BBR, more tissue was formed, with longer roots, thicker root walls, and smaller apex diameters. In addition, we found that BBR promoted SCAPs osteogenesis in a time-dependent and concentration-dependent manner. BBR induced the expression of β-catenin and enhanced β-catenin entering into the nucleus, to up-regulate more runt-related nuclear factor 2 downstream. BBR enhanced root repair in immature teeth with apical periodontitis by activating the canonical Wnt/β-catenin pathway in SCAPs.
Animals ; Berberine ; pharmacology ; Cell Differentiation ; drug effects ; Dental Papilla ; Male ; Osteogenesis ; drug effects ; Periapical Periodontitis ; therapy ; Rats ; Stem Cells ; cytology ; drug effects ; metabolism ; Wnt Signaling Pathway ; drug effects ; Wnt3A Protein ; genetics ; metabolism ; X-Ray Microtomography

The present study was aimed to investigate the effects and mechanisms of electro-acupuncture (EA) on proliferation and differentiation of neural stem cells in the hippocampus of C57 mice exposed to different doses of X-ray radiation. Thirty-day-old C57BL/6J mice were randomly divided into control, irradiation, and EA groups. The control group was not treated with irradiation. The irradiation groups were exposed to different doses of X-ray (4, 8 or 16 Gy) for 10 min. The EA groups were electro-acupunctured at Baihui, Fengfu and bilateral Shenyu for 3 courses of treatment after X-ray radiation. Immunohistochemistry was used to evaluate proliferation and differentiation of the hippocampal neural stem cell. RT-PCR and Western blot were used to detect mRNA and protein expressions of Notch1 and Mash1 in the hippocampus, respectively. The results showed that, compared with the control group, the numbers of BrdU positive cells (4, 8 Gy subgroup) and BrdU/NeuN double-labeling positive cells (3 dose subgroups) were decreased significantly in the irradiation group, but the above changes could be reversed by EA. Compared with the control group, the number of BrdU/GFAP double-labeling positive cells in each dose subgroup of irradiation group was decreased significantly, while EA could reverse the change of 4 and 8 Gy dose subgroups. In addition, compared with the control group, the expression levels of Notch1 mRNA and protein in hippocampus were up-regulated, and the expression levels of Mash1 mRNA and protein were significantly decreased in each dose subgroup of irradiation group. Compared with irradiation group, the expression levels of Notch1 mRNA and protein in hippocampus of EA group were decreased significantly in each dose subgroup, and the expression levels of Mash1 mRNA and protein were increased significantly in 4 and 8 Gy subgroups. These results suggest that irradiation affects the proliferation and differentiation of neural stem cells in hippocampus of mice, whereas EA may significantly increase the proliferation and differentiation of hippocampal neural stem cells via the regulation of Notch signaling pathway.
Animals ; Basic Helix-Loop-Helix Transcription Factors ; metabolism ; Cell Differentiation ; Cell Proliferation ; Electroacupuncture ; Hippocampus ; cytology ; radiation effects ; Mice, Inbred C57BL ; Neural Stem Cells ; cytology ; radiation effects ; Random Allocation ; Receptor, Notch1 ; metabolism ; X-Rays ; adverse effects

OBJECTIVE: To explore the protective effect of NANOG against hydrogen peroxide (H2O2) -induced cell damage in the human hair follicle mesenchymal stem cells (hHF-MSCs). METHODS: NANOG was expressed from a lentiviral vector, pLVX-IRES-ZsGreen. NANOG hHF-MSCs and vector hHF-MSCs were treated with 400 μmol/L hydrogen peroxide (H2O2) for 2 h, the cell survival rate, cell morphology, ROS production, apoptosis and expression of AKT, ERK, and p21 were determined and compared. RESULTS: Our results showed that NANOG could activate AKT and upregulate the expression of p-AKT, but not p-ERK. When treated with 400 μmol/L H2O2, NANOG hHF-MSCs showed higher cell survival rate, lower ROS production and apoptosis, higher expression of p-AKT, higher ratio of p-AKT/AKT. CONCLUSION Our results suggest that NANOG could protect hHF-MSCs against cell damage caused by H2O2 through activating AKT signaling pathway.
Cell Survival ; Drug Evaluation, Preclinical ; Hair Follicle ; cytology ; Humans ; Hydrogen Peroxide ; Lentivirus ; Mesenchymal Stem Cells ; drug effects ; metabolism ; Nanog Homeobox Protein ; metabolism ; pharmacology ; Oxidative Stress ; drug effects ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction

OBJECTIVE: To isolate tumor stem-like cells from human epithelial ovarian cancer SKOV3 cells and explore their role in the formation of vascularization mimicry (VM). METHODS: SKOV3 cells were passaged to the 7th generation by suspension culture in serum-free medium, and the percentages of CD133- and CD117-positive cells in the 1st, 3rd, 5th and 7th generations were analyzed using flow cytometry. The proliferative activity of the cells sorted from the 7th generation SKOV3 cells was assessed with colony formation assay. A three-dimensional cell culture model was established to compare the ability of VM formation between the sorted cells and the parental SKOV3 cells. The expression levels of matrix metalloproteinases-2 (MMP-2) and MMP-9 in the two groups were detected using real-time PCR and Western blotting. RESULTS: Some SKOV3 cells formed typical cell spheres with suspension growth in serum-free medium and were passaged to the 7th generation. Flow cytometry revealed that the percentage of CD133-positive cells increased with cell passaging. The cloning efficiency of the sorted cells was significantly higher than that of the parental SKOV3 cells (50.33% 5.33%, < 0.001). The VM formation ability of the sorted cells was stronger than that of the parental SKOV3 cells in the three-dimensional cell culture system. RT-PCR and Western blotting showed that the expression levels of MMP-2 and MMP-9 were significantly higher in the 7th passage cells than in the parental cells ( < 0.05). CONCLUSIONS The sorted cells from SKOV3 cells cultured in serum-free medium exhibit biological properties of tumor stem cells with strong VM formation ability, suggesting their role in VM formation.
Carcinoma, Ovarian Epithelial ; pathology ; Cell Line, Tumor ; Cell Movement ; Female ; Humans ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Neoplastic Stem Cells ; cytology ; Neovascularization, Pathologic ; pathology ; Ovarian Neoplasms ; pathology

To compare the biological functions of astrocytes cultured by two methods. Methods The primary astrocytes were cultured from rodent neonatal brain,whereas the differentiated astrocytes were prepared by differentiating neural stem cells with fetal bovine serum.The morphologies of these two different types of astrocytes were observed under microscope and the expression of glial fibrillary acidic protein(GFAP),an astrocyte-specific marker,was detected by immunofluorescence staining after treatment with 10 cytokines.Changes in GFAP,glutamate synthetase(GS),glutamate-aspartic acid transporter(xCT),neuregulin-1(NRG),N-methyl-D-aspartic acid receptor(NMDA),lipoprotein lipase(LPL)were detected and compared. Results The morphologies and GFAP expression differed between these two astrocyte types.Microarray showed that the expressions of GFAP,GS,xCT,NRG,NMDA,and LPL were significantly higher in primary astrocytes than in differentiated astrocytes.None of these 10 cytokines increased the expression of GFAP in primary astrocytes,whereas treatment with transforming growth factor-β(TGF-β)significantly increased the expression of GFAP in the differentiated astrocytes. Conclusion Compared with the differentiated astrocytes,the primary astrocytes are more similar to reactive astrocytes,and TGF-β can promote the transition of differentiated cells to reactive cells.
Animals ; Animals, Newborn ; Astrocytes ; cytology ; Cell Differentiation ; Cells, Cultured ; Glial Fibrillary Acidic Protein ; metabolism ; Neural Stem Cells ; cytology ; Rodentia ; Transforming Growth Factor beta ; pharmacology

Objective To analyze the differences in biological functions between bone marrow(BM)-derived CD106 mesenchymal stem cells(MSCs)and the CD106 subgroup. Methods The MSCs from normal BM were isolated and expanded.The subgroups of CD106 and CD106 MSCs were sorted.The cell proliferation and adhesion functions,chemotactic activities,adipogenic and osteogenic potentials,senescence,and senescence protein 21(p21)were detected.The capacity of translocation into nucleus of nuclear factor-kappa B(NF-κB)when stimulated by tumor necrosis factor(TNF-α)was measured. Results The proliferative ability was higher in CD106 MSCs than that in CD106 MSCs.In 48 hours,the value of optical density(OD)was significantly higher in CD106 MSCs than that in CD106 subgroup(1.004±0.028 0.659±0.023,=3.946,=0.0225).In 72 hours,this phenomenon was even more pronounced(2.574±0.089 1.590±0.074,=11.240,=0.0000).The adhesive capacity of CD106 MSCs was significantly stronger than that of CD106 subgroup(0.648±0.018 0.418±0.023,=7.869,=0.0002).Besides,the metastasis ability of CD106 MSCs were significantly stronger than that of CD106 subgroup(114.500±4.481 71.000±4.435,=6.900,=0.0005).The CD106 MSCs had signifcnatly lower proportions of senescent cells.The expression of aging protein p21 in CD106 MSCs was significantly lower than that in CD106 MSCs [(17.560±1.421)% (45.800±2.569)%,=9.618,=0.0000].Furthermore,there were no visible pigmenting cells after β-galactosidase staining in CD106 MSCs subgroup.However,in CD106 MSCs,some colored green cells were detected.The rate of NF-κB translocation into nucleus after stimulated by TNF-α was significantly higher in CD106 MSCs than CD106 MSCs [(37.780±3.268)% (7.30±1.25)%,=8.713,=0.0001]. Conclusion Bone marrow-derived CD106 MSCs possess more powerful biological functions than CD106 MSCs.
Bone Marrow Cells ; cytology ; Cell Adhesion ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Humans ; Mesenchymal Stem Cells ; cytology ; NF-kappa B ; metabolism ; Protein Transport ; Tumor Necrosis Factor-alpha ; pharmacology ; Vascular Cell Adhesion Molecule-1 ; metabolism

OBJECTIVE: To study the effect of exendin-4(Ex-4) on the differentiation of neural stem cells(NSCs) in adult mouse subventricular zone(SVZ)and its mechanism . METHODS: NSCs in the SVZ were derived from 5-week C57BL/6J mice and the expression of nestin was detected by immunofluorescence. The cell morphology was observed after the cells treatmed with 100 nmol/L Ex-4 for 14 days.The expressions of nestin and glucagon-like peptide-1 receptor (GLP-1R) were detected by immunofluorescence. GLP-1R was knocked down by using shRNA and the study was divided into four groups: control group, Ex-4 group, GLP-1R knockdown group, GLP-1R knockdown + Ex-4 group. After treatment with 100 nmol/L Ex-4 for 14 d, β-tublin III and glial fibrillary acidic protein (GFAP) were labeled by immunofluorescence and then the proportion of β-tublin III positive cells were counted. Western blot was used to detect the activation of cAMP-response element binding protein (CREB) in NSCs. In order to further study the effects of Ex-4 on mitogen-activated protein kinase(MAPK) and phosphatidylinositol 3-hydroxy kinase (PI3K) pathways, the cells were pretreated with MAPK inhibitor U0126 at a concentration of 0.07 μmol/L for 30 min or PI3K inhibitor LY294002 at 50 μmol for 2 h, respectively. The study was divided into six groups: control group, Ex-4 group, U0126 group, U0126 + Ex-4 group, LY294002 group, LY294002 + Ex-4 group. The activation of CREB in each group was detected by Western blot. The experiment was repeated three times independently. RESULTS: NSCs were successfully extracted from SVZ of C57BL/6J mice. Immunofluorescence showed that nestin and GLP-1R were positive in NSCs. Compared with the control group, the proportion of neurons differentiated from Ex-4 group was higher. The percentage of neurons in GLP-1R knockdown + Ex-4 group was basically the same as that in control group (P＜0.01). The positive cells of beta-tublin III showed positive activation of GLP-1R and CREB. Western blot showed that CREB was significantly activated in the Ex-4 group, and knockdown of GLP-1R abolished its activation (P＜0.01). U0126 did not affect Ex-4-mediated CERB activation, and LY294002 significantly reduced Ex-4-mediated CREB activation (P＜0.01). CONCLUSION Ex-4 promotes the differentiation of NSCs into neurons in SVZ of adult mice through GLP-1R receptor, which may be achieved through PI3K/CREB pathway.
Animals ; Cell Differentiation ; Cells, Cultured ; Cyclic AMP Response Element-Binding Protein ; metabolism ; Exenatide ; pharmacology ; Gene Knockdown Techniques ; Glucagon-Like Peptide-1 Receptor ; genetics ; metabolism ; Lateral Ventricles ; cytology ; Mice ; Mice, Inbred C57BL ; Neural Stem Cells ; cytology ; Phosphatidylinositol 3-Kinases