OBJECTIVE: To Investigate the effects of lithocholic acid (LCA) on the balance between osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). METHODS: Twelve 10-week-old SPF C57BL/6J female mice were randomly divided into an experimental group (undergoing bilateral ovariectomy) and a control group (only removing the same volume of adipose tissue around the ovaries), with 6 mice in each group. The body mass was measured every week after operation. After 4 weeks post-surgery, the weight of mouse uterus was measured, femur specimens of the mice were taken for micro-CT scanning and three-dimensional reconstruction to analyze changes in bone mass. Tibia specimens were taken for HE staining to calculate the number and area of bone marrow adipocytes in the marrow cavity area. ELISA was used to detect the expression of bone turnover markers in the serum. Liver samples were subjected to real-time fluorescence quantitative PCR (RT-qPCR) to detect the expression of key genes related to bile acid metabolism, including cyp7a1, cyp7b1, cyp8b1, and cyp27a1. BMSCs were isolated by centrifugation from 2 C57BL/6J female mice (10-week-old). The third-generation cells were exposed to 0, 1, 10, and 100 μmol/L LCA, following which cell viability was evaluated using the cell counting kit 8 assay. Subsequently, alkaline phosphatase (ALP) staining and oil red O staining were conducted after 7 days of osteogenic and adipogenic induction. RT-qPCR was employed to analyze the expressions of osteogenic-related genes, namely ALP, Runt-related transcription factor 2 (Runx2), and osteocalcin (OCN), as well as adipogenic-related genes including Adiponectin (Adipoq), fatty acid binding protein 4 (FABP4), and peroxisome proliferator-activated receptor γ (PPARγ). RESULTS: Compared with the control group, the body mass of the mice in the experimental group increased, the uterus atrophied, the bone mass decreased, the bone marrow fat expanded, and the bone metabolism showed a high bone turnover state. RT-qPCR showed that the expressions of cyp7a1, cyp8b1, and cyp27a1, which were related to the key enzymes of bile acid metabolism in the liver, decreased significantly ( P<0.05), while the expression of cyp7b1 had no significant difference ( P>0.05). Intervention with LCA at concentrations of 1, 10, and 100 μmol/L did not demonstrate any apparent toxic effects on BMSCs. Furthermore, LCA inhibited the expressions of osteogenic-related genes (ALP, Runx2, and OCN) in a dose-dependent manner, resulting in a reduction in ALP staining positive area. Concurrently, LCA promoted the expressions of adipogenic-related genes (Adipoq, FABP4, and PPARγ), and an increase in oil red O staining positive area. CONCLUSION After menopause, the metabolism of bile acids is altered, and secondary bile acid LCA interferes with the balance of osteogenic and adipogenic differentiation of BMSCs, thereby affecting bone remodelling.
Female ; Mice ; Animals ; Core Binding Factor Alpha 1 Subunit/pharmacology* ; PPAR gamma/metabolism* ; Steroid 12-alpha-Hydroxylase/metabolism* ; Mice, Inbred C57BL ; Cell Differentiation ; Osteogenesis ; Mesenchymal Stem Cells ; Bile Acids and Salts/pharmacology* ; Bone Marrow Cells ; Cells, Cultured ; Azo Compounds

BACKGROUND: Hair follicles are easily accessible and contain stem cells with different developmental origins, including mesenchymal stem cells (MSCs), that consequently reveal the potential of human hair follicle (hHF)-derived MSCs in repair and regeneration. However, the role of hHF-MSCs in Achilles tendinopathy (AT) remains unclear. The present study investigated the effects of hHF-MSCs on Achilles tendon repair in rabbits. METHODS: First, we extracted and characterized hHF-MSCs. Then, a rabbit tendinopathy model was constructed to analyze the ability of hHF-MSCs to promote repair in vivo . Anatomical observation and pathological and biomechanical analyses were performed to determine the effect of hHF-MSCs on AT, and quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemical staining were performed to explore the molecular mechanisms through which hHF-MSCs affects AT. Furthermore, statistical analyses were performed using independent sample t test, one-way analysis of variance (ANOVA), and one-way repeated measures multivariate ANOVA as appropriate. RESULTS: Flow cytometry, a trilineage-induced differentiation test, confirmed that hHF-derived stem cells were derived from MSCs. The effect of hHF-MSCs on AT revealed that the Achilles tendon was anatomically healthy, as well as the maximum load carried by the Achilles tendon and hydroxyproline proteomic levels were increased. Moreover, collagen I and III were upregulated in rabbit AT treated with hHF-MSCs (compared with AT group; P  < 0.05). Analysis of the molecular mechanisms revealed that hHF-MSCs promoted collagen fiber regeneration, possibly through Tenascin-C (TNC) upregulation and matrix metalloproteinase (MMP)-9 downregulation. CONCLUSIONS hHF-MSCs can be a treatment modality to promote AT repair in rabbits by upregulating collagen I and III. Further analysis revealed that treatment of AT using hHF-MSCs promoted the regeneration of collagen fiber, possibly because of upregulation of TNC and downregulation of MMP-9, thus suggesting that hHF-MSCs are more promising for AT.
Animals ; Humans ; Rabbits ; Hair Follicle ; Achilles Tendon/pathology* ; Tendinopathy/pathology* ; Proteomics ; Collagen Type I ; Mesenchymal Stem Cells

In recent years, mesenchymal stem cell (MSCs)-derived exosomes have attracted much attention in the field of tissue regeneration. Mesenchymal stem cell-derived exosomes are signaling molecules for communication among cells. They are characterized by natural targeting and low immunogenicity, and are mostly absorbed by cells through the paracrine pathway of mesenchymal stem cells. Moreover, they participate in the regulation and promotion of cell or tissue regeneration. As a scaffold material in regenerative medicine, hydrogel has good biocompatibility and degradability. Combining the two compounds can not only improve the retention time of exosomes at the lesion site, but also improve the dose of exosomes reaching the lesion site by in situ injection, and the therapeutic effect in the lesion area is significant and continuous. This paper summarizes the research results of the interaction of exocrine and hydrogel composite materials to promote tissue repair and regeneration, in order to facilitate research in the field of tissue regeneration in the future.
Hydrogels/metabolism* ; Exosomes/metabolism* ; Wound Healing ; Regenerative Medicine ; Mesenchymal Stem Cells/metabolism*

A triple-transgenic (tyrosine hydroxylase/dopamine decarboxylase/GTP cyclohydrolase 1, TH/DDC/GCH1) bone marrow mesenchymal stem cell line (BMSCs) capable of stably synthesizing dopamine (DA) transmitters were established to provide experimental evidence for the clinical treatment of Parkinson's disease (PD) by using this cell line. The DA-BMSCs cell line that could stably synthesize and secrete DA transmitters was established by using the triple transgenic recombinant lentivirus. The triple transgenes (TH/DDC/GCH1) expression in DA-BMSCs was detected using reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and immunofluorescence. Moreover, the secretion of DA was tested by enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC). Chromosome G-banding analysis was used to detect the genetic stability of DA-BMSCs. Subsequently, the DA-BMSCs were stereotactically transplanted into the right medial forebrain bundle (MFB) of Parkinson's rat models to detect their survival and differentiation in the intracerebral microenvironment of PD rats. Apomorphine (APO)-induced rotation test was used to detect the improvement of motor dysfunction in PD rat models with cell transplantation. The TH, DDC and GCH1 were expressed stably and efficiently in the DA-BMSCs cell line, but not expressed in the normal rat BMSCs. The concentration of DA in the cell culture supernatant of the triple transgenic group (DA-BMSCs) and the LV-TH group was extremely significantly higher than that of the standard BMSCs control group (P < 0.000 1). After passage, DA-BMSCs stably produced DA. Karyotype G-banding analysis showed that the vast majority of DA-BMSCs maintained normal diploid karyotypes (94.5%). Moreover, after 4 weeks of transplantation into the brain of PD rats, DA-BMSCs significantly improved the movement disorder of PD rat models, survived in a large amount in the brain microenvironment, differentiated into TH-positive and GFAP-positive cells, and upregulated the DA level in the injured area of the brain. The triple-transgenic DA-BMSCs cell line that stably produced DA, survived in large numbers, and differentiated in the rat brain was successfully established, laying a foundation for the treatment of PD using engineered culture and transplantation of DA-BMSCs.
Rats ; Animals ; Dopamine ; Parkinson Disease/metabolism* ; Mesenchymal Stem Cells/metabolism* ; Cell Line ; Brain/metabolism* ; Cell Differentiation ; Mesenchymal Stem Cell Transplantation

OBJECTIVE: To investigate the regulatory effects of miR-26a-5p on the osteogenic differentiation of adipose-derived mesenchymal stem cells (ADSCs) by regulating cAMP response element binding protein 1 (CREB1). METHODS: The adipose tissues of four 3-4 weeks old female C57BL/6 mice were collected and the cells were isolated and cultured by digestion separation method. After morphological observation and identification by flow cytometry, the 3rd-generation cells were subjected to osteogenic differentiation induction. At 0, 3, 7, and 14 days after osteogenic differentiation induction, the calcium deposition was observed by alizarin red staining, ALP activity was detected, miR- 26a-5p and CREB1 mRNA expressions were examined by real-time fluorescence quantitative PCR, and CREB1 protein and its phosphorylation (phospho-CREB1, p-CREB1) level were measured by Western blot. After the binding sites between miR-26a-5p and CREB1 was predicted by the starBase database, HEK-293T cells were used to conduct a dual-luciferase reporter gene experiment to verify the targeting relationship (represented as luciferase activity after 48 hours of culture). Finally, miR-26a-p inhibitor (experimental group) and the corresponding negative control (control group) were transfected into ADSCs. Alizarin red staining, ALP activity, real-time fluorescent quantitative PCR (miR-26a-5p) and Western blot [CREB1, p-CREB1, Runt-related transcription factor 2 (RUNX2), and osteocalcin (OCN)] were performed at 7 and 14 days after osteogenic induction culture. RESULTS: The cultured cells were identified as ADSCs. With the prolongation of osteogenic induction culture, the number of calcified nodules and ALP activity significantly increased ( P<0.05). The relative expression of miR-26a-5p in the cells gradually decreased, while the relative expressions of CREB1 mRNA and protein, as well as the relative expression of p-CREB1 protein were increased. The differences were significant between 7, 14 days and 0 day ( P<0.05). There was no significant difference in p-CREB1/CREB1 between different time points ( P>0.05). The starBase database predicted that miR-26a-5p and CREB1 had targeted binding sequences, and the dual-luciferase reporter gene experiment revealed that overexpression of miR-26a-5p significantly suppressed CREB1 wild-type luciferase activity ( P<0.05). After 7 and 14 days of osteogenic induction, compared with the control group, the number of calcified nodules, ALP activity, and relative expressions of CREB1, p-CREB1, OCN, and RUNX2 proteins in the experimental group significantly increased ( P<0.05). There was no significant difference in p-CREB1/CREB1 between the two groups ( P>0.05). CONCLUSION Knocking down miR-26a-5p promoted the osteogenic differentiation of ADSCs by up-regulating CREB1 and its phosphorylation.
Animals ; Female ; Mice ; Cell Differentiation ; Cells, Cultured ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Cyclic AMP Response Element-Binding Protein/metabolism* ; Mesenchymal Stem Cells ; Mice, Inbred C57BL ; MicroRNAs/metabolism* ; Osteocalcin/metabolism* ; Osteogenesis/genetics* ; RNA, Messenger/genetics*

Objective To investigate the effects of miR-877-3p on migration and apoptotic T lymphocytes of bone mesenchymal stem cells (BMSCs). Methods The model of osteoporosis induced by bilateral ovariectomy (OVX) and sham operation was established. At 8 weeks after operation, the bone parameters of the two groups were detected by micro-CT. The levels of monocyte chemotactic protein 1(MCP-1) in BMSCs were detected by ELISA. BMSC in OVX group and sham group were co-cultured with T lymphocytes, respectively. The migration ability of T lymphocytes in the two groups was observed by Transwell^TM assay with PKH26 staining and apoptosis of T lymphocytes were detected by flow cytometry. Reverse transcription PCR was used to detect the expression of miR-877-3p in BMSCs. miR-877-3p was overexpressed or down-regulated by cell transfection. The level of MCP-1 secreted by BMSCs in each group was detected by ELISA. The migration and apoptosis of T lymphocytes were detected by the above methods. Results The number of trabecular bone and bone mineral density in OVX group were lower than those in sham group. The levels of MCP-1 secretion, chemotactic and apoptotic T lymphocyte ability of BMSCs in OVX group were also lower than those in sham group. The expression level of miR-877-3p in BMSC in OVX group was higher than that in sham group. After overexpression of BMSC miR-877-3p, the levels of MCP-1 secreted from BMSCs, and apoptotic T lymphocytes decreased, while the results were opposite after down-regulation of miR-877-3p. Conclusion miR-877-3p may be one of the causes of osteoporosis by inhibiting MCP-1 secretion of BMSCs and the migration and apoptosis of T lymphocytes.
Animals ; Female ; Mice ; Apoptosis/genetics* ; Bone Marrow Cells/metabolism* ; Cell Differentiation ; Chemokine CCL2/metabolism* ; Mesenchymal Stem Cells/metabolism* ; MicroRNAs/metabolism* ; Osteogenesis ; Osteoporosis/genetics* ; T-Lymphocytes/metabolism*

Objective To investigate the effect of H₂O₂-induced oxidative stress on autophagy and apoptosis of human bone marrow mesenchymal stem cells (hBMSCs). Methods hBMSCs were isolated and cultured. The cells were divided into control group, 3-MA group, H₂O₂ group, H₂O₂ combined with 3-MA group. DCFH-DA staining was used to analyze the level of reactive oxygen species (ROS). hBMSCs were treated with 0, 50, 100, 200, 400 μmol/L H₂O₂, and then the cell viability was detected by CCK-8 assay. The level of autophagy was detected by monodansylcadaverine (MDC) staining and LysoTracker Red staining. The cell apoptosis was detected by flow cytometry. Western blotting was used to detect the expression of beclin 1, mTOR, phosphorylated mTOR (p-mTOR), cleaved caspase-3(c-caspase-3) and caspase-3 proteins. Results Compared with the control group and 3-MA group, ROS level and autophagosomes were increased and the proliferation and apoptosis were decreased in H₂O₂ group. The protein expression of beclin 1, mTOR, c-caspase-3 was up-regulated, while the p-mTOR was down-regulated. Compared with the 3-MA group, the H₂O₂ combined with 3-MA group also had an increased ROS level and autophagosomes, but not with significantly increased apoptosis rate; The protein expression of beclin 1, mTOR, c-caspase-3 was up-regulated, and the p-mTOR was down-regulated. Conclusion H₂O₂ can induce hMSCs to trigger oxidative stress response. It enhances the autophagy and inhibits the proliferation and apoptosis of hBMSCs.
Humans ; Beclin-1/metabolism* ; Caspase 3/metabolism* ; Reactive Oxygen Species/metabolism* ; Hydrogen Peroxide/pharmacology* ; Apoptosis ; TOR Serine-Threonine Kinases/metabolism* ; Oxidative Stress ; Autophagy ; Mesenchymal Stem Cells/metabolism* ; Cell Proliferation

OBJECTIVE: To investigate the therapeutic effects of total glucosides of paeony (TGP) on psoriasis based on the immunomodulatory effect of dermal mesenchymal stem cells (DMSCs). METHODS: A total of 30 male BALB/c mice were divided into 6 groups (n=5 in each) by a random number table method, including control, psoriasis model (model, 5% imiquimod cream 42 mg/d), low-, medium- and high-dose TGP (50, 100, and 200 mg/kg, L, M-, and H-TGP, respectively), and positive control group (2.5 mg/kg acitretin). After 14 days of continuous administration, the skin's histopathological changes, apoptosis, secretion of inflammatory cytokines, and proportion of regulatory T cells (Treg) and T helper cell 17 (Th17) were evaluated using hematoxylin-eosin (HE) staining, TdT-mediated dUTP nick end labeling staining, enzyme-linked immunosorbent assay, and flow cytometry, respectively. DMSCs were further isolated from the skin tissues of normal and psoriatic mice, and the cell morphology, phenotype, and cycle were observed. Furthermore, TGP was used to treat psoriatic DMSCs to analyze the effects on the DMSCs immune regulation. RESULTS: TGP alleviated skin pathological injury, reduced epidermis layer thickness, inhibited apoptosis, and regulated the secretion of inflammatory cytokines and the proportion of Treg and Th17 in the skin tissues of psoriatic mice (P<0.05 or P<0.01). There was no significant difference in cell morphology and phenotype between control and psoriatic DMSCs (P>0.05), however, more psoriatic DMSCs remained in G₀/G₁ phase compared with the normal DMSCs (P<0.01). TGP treatment of psoriatic DMSCs significantly increased cell viability, decreased apoptosis, relieved inflammatory response, and inhibited the expression of toll-like receptor 4 and P65 (P<0.05 or P<0.01). CONCLUSION TGP may exert a good therapeutic effect on psoriasis by regulating the immune imbalance of DMSCs.
Male ; Animals ; Mice ; Psoriasis/drug therapy* ; Cytokines ; Glucosides/therapeutic use* ; Mesenchymal Stem Cells ; Mice, Inbred BALB C ; Paeonia

Salivary gland (SG) dysfunction, due to radiotherapy, disease, or aging, is a clinical manifestation that has the potential to cause severe oral and/or systemic diseases and compromise quality of life. Currently, the standard-of-care for this condition remains palliative. A variety of approaches have been employed to restore saliva production, but they have largely failed due to damage to both secretory cells and the extracellular matrix (niche). Transplantation of allogeneic cells from healthy donors has been suggested as a potential solution, but no definitive population of SG stem cells, capable of regenerating the gland, has been identified. Alternatively, mesenchymal stem cells (MSCs) are abundant, well characterized, and during SG development/homeostasis engage in signaling crosstalk with the SG epithelium. Further, the trans-differentiation potential of these cells and their ability to regenerate SG tissues have been demonstrated. However, recent findings suggest that the "immuno-privileged" status of allogeneic adult MSCs may not reflect their status post-transplantation. In contrast, autologous MSCs can be recovered from healthy tissues and do not present a challenge to the recipient's immune system. With recent advances in our ability to expand MSCs in vitro on tissue-specific matrices, autologous MSCs may offer a new therapeutic paradigm for restoration of SG function.
Mesenchymal Stem Cell Transplantation ; Mesenchymal Stem Cells ; Quality of Life ; Regeneration ; Salivary Glands ; Stem Cells

Although the mTOR-4E-BP1 signaling pathway is implicated in aging and aging-related disorders, the role of 4E-BP1 in regulating human stem cell homeostasis remains largely unknown. Here, we report that the expression of 4E-BP1 decreases along with the senescence of human mesenchymal stem cells (hMSCs). Genetic inactivation of 4E-BP1 in hMSCs compromises mitochondrial respiration, increases mitochondrial reactive oxygen species (ROS) production, and accelerates cellular senescence. Mechanistically, the absence of 4E-BP1 destabilizes proteins in mitochondrial respiration complexes, especially several key subunits of complex III including UQCRC2. Ectopic expression of 4E-BP1 attenuates mitochondrial abnormalities and alleviates cellular senescence in 4E-BP1-deficient hMSCs as well as in physiologically aged hMSCs. These f indings together demonstrate that 4E-BP1 functions as a geroprotector to mitigate human stem cell senescence and maintain mitochondrial homeostasis, particularly for the mitochondrial respiration complex III, thus providing a new potential target to counteract human stem cell senescence.
Mesenchymal Stem Cells/physiology* ; Cellular Senescence ; Homeostasis ; Cell Cycle Proteins/metabolism* ; Adaptor Proteins, Signal Transducing/metabolism* ; Mitochondria/metabolism* ; Electron Transport Complex III/metabolism* ; Humans ; Cells, Cultured