1.Impact of lithocholic acid on the osteogenic and adipogenic differentiation balance of bone marrow mesenchymal stem cells.
Cui WANG ; Jiao LI ; Lingyun LU ; Lu LIU ; Xijie YU
Chinese Journal of Reparative and Reconstructive Surgery 2024;38(1):82-90
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
2.Baicalin attenuates dexamethasone-induced apoptosis of bone marrow mesenchymal stem cells by activating the hedgehog signaling pathway.
Bin JIA ; Yaping JIANG ; Yao YAO ; Yingxing XU ; Yingzhen WANG ; Tao LI
Chinese Medical Journal 2023;136(15):1839-1847
BACKGROUND:
Perturbations in bone marrow mesenchymal stem cell (BMSC) differentiation play an important role in steroid-induced osteonecrosis of the femoral head (SONFH). At present, studies on SONFH concentrate upon the balance within BMSC osteogenic and adipogenic differentiation. However, BMSC apoptosis as well as proliferation are important prerequisites in their differentiation. The hedgehog (HH) signaling pathway regulates bone cell apoptosis. Baicalin (BA), a well-known compound in traditional Chinese medicine, can affect the proliferation and apoptosis of numerous cell types via HH signaling. However, the potential role and mechanisms of BA on BMSCs are unclear. Thus, we aimed to explore the role of BA in dexamethasone (Dex)-induced BMSC apoptosis in this study.
METHODS:
Primary BMSCs were treated with 10 -6 mol/L Dex alone or with 5.0 μmol/L, 10.0 μmol/L, or 50.0 μmol/L BA for 24 hours followed by co-treatment with 5.0 μmol/L, 10.0 μmol/L, or 50.0 μmol/L BA and 10 -6 mol/L Dex. Cell viability was assayed through the Cell Counting Kit-8 (CCK-8). Cell apoptosis was evaluated using Annexin V-fluorescein isothiocyanate/propidium iodide (PI) staining followed by flow cytometry. The imaging and counting, respectively, of Hochest 33342/PI-stained cells were used to assess the morphological characteristics and proportion of apoptotic cells. To quantify the apoptosis-related proteins (e.g., apoptosis regulator BAX [Bax], B-cell lymphoma 2 [Bcl-2], caspase-3, and cleaved caspase-3) and HH signaling pathway proteins, western blotting was used. A HH-signaling pathway inhibitor was used to demonstrate that BA exerts its anti-apoptotic effects via the HH signaling pathway.
RESULTS:
The results of CCK-8, Hoechst 33342/PI-staining, and flow cytometry showed that BA did not significantly promote cell proliferation (CCK-8: 0 μmol/L, 100%; 2.5 μmol/L, 98.58%; 5.0 μmol/L, 95.18%; 10.0 μmol/L, 98.11%; 50.0 μmol/L, 99.38%, F = 2.33, P > 0.05), but it did attenuate the effect of Dex on apoptosis (Hoechst 33342/PI-staining: Dex+ 50.0 μmol/L BA, 12.27% vs. Dex, 39.27%, t = 20.62; flow cytometry: Dex + 50.0 μmol/L BA, 12.68% vs. Dex, 37.43%, t = 11.56; Both P < 0.05). The results of western blotting analysis showed that BA reversed Dex-induced apoptosis by activating the HH signaling pathway, which down-regulated the expression of Bax, cleaved-caspase 3, and suppressor of fused (SUFU) while up-regulating Bcl-2, sonic hedgehog (SHH), and zinc finger protein GLI-1 (GLI-1) expression (Bax/Bcl-2: Dex+ 50.0 μmol/L BA, 1.09 vs. Dex, 2.76, t = 35.12; cleaved caspase-3/caspase-3: Dex + 50.0 μmol/L BA, 0.38 vs . Dex, 0.73, t = 10.62; SHH: Dex + 50.0 μmol/L BA, 0.50 vs . Dex, 0.12, t = 34.01; SUFU: Dex+ 50.0 μmol/L BA, 0.75 vs . Dex, 1.19, t = 10.78; GLI-1: Dex+ 50.0 μmol/L BA, 0.40 vs . Dex, 0.11, t = 30.68. All P < 0.05).
CONCLUSIONS
BA antagonizes Dex-induced apoptosis of human BMSCs by activating the HH signaling pathway. It is a potential candidate for preventing SONFH.
Humans
;
Hedgehog Proteins/metabolism*
;
bcl-2-Associated X Protein
;
Caspase 3/metabolism*
;
Signal Transduction/physiology*
;
Apoptosis
;
Apoptosis Regulatory Proteins/pharmacology*
;
Dexamethasone/pharmacology*
;
Mesenchymal Stem Cells/metabolism*
;
Bone Marrow Cells
3.Effect of Wnt/β-catenin signaling pathway in neural differentiation of human bone marrow mesenchymal stem cells.
Chinese Journal of Reparative and Reconstructive Surgery 2023;37(10):1276-1283
OBJECTIVE:
To explore the effect of basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and the combination of bFGF and EGF in the neural differentiation of human bone marrow mesenchymal stem cells (hBMSCs), and the role of Wnt/β-catenin signaling pathway in this process.
METHODS:
The identified 4th-generation hBMSCs were divided into five groups according to different induction conditions, namely control group (group A), EGF induction group (group B), bFGF induction group (group C), EGF and bFGF combined induction group (group D), and EGF, bFGF, and Dickkopf-related protein 1 (DKK-1) combined induction group (group E). After 7 days of continuous induction, the cell morphology was observed by inverted fluorescence phase contrast microscopy, levels of genes that were related to neural cells [Nestin, neuron-specific enolase (NSE), microtubule-associated protein 2 (MAP-2), and glial fibrillary acidic protein (GFAP)] and key components of the Wnt/β-catenin signaling pathway (β-catenin and Cyclin D1) were detected by RT-PCR, and the levels of proteins that were related to neural cells (Nestin and GFAP) as well as genes that were involved in Wnt/β-catenin signaling pathway [β-catenin, phosphorylation β-catenin (P-β-catenin), Cytoplasmic β-catenin, and Nuclear β-catenin] were explored by cellular immunofluorescence staining and Western blot.
RESULTS:
When compared to groups A and B, the typical neuro-like cell changes were observed in groups C-E, and most obviously in group D. RT-PCR showed that the relative expressions of Nestin, NSE, and MAP-2 genes in groups C-E, the relative expressions of GFAP gene in groups D and E, the relative expression of NSE gene in group B, the relative expressions of β-catenin gene in groups C and D, and the relative expressions of Cyclin D1 gene in groups B-D significantly increased when compared with group A ( P<0.05). Compared with group E, the relative expressions of Nestin, NSE, MAP-2, GFAP, β-catenin, and CyclinD1 genes significantly increased in group D ( P<0.05); compared with group C, the relative expression of Nestin gene in group D significantly decreased ( P<0.05), while NSE, MAP-2, and GFAP genes significantly increased ( P<0.05). The cellular immunofluorescence staining showed that the ratio of NSE- and GFAP-positive cells significantly increased in groups C-E than in group A, in group D than in groups C and E ( P<0.05). Western blot assay showed that the relative expression of NSE protein was significantly higher in groups C and D than in group A and in group D than in groups C and E ( P<0.05). In addition, the relative expression of GFAP protein was significantly higher in groups C-E than in group A and in group D than in group E ( P<0.05). Besides, the relative expressions of β-catenin, Cytoplasmic β-catenin, Nuclear β-catenin, and the ratio of Nuclear β-catenin to Cytoplasmic β-catenin were significantly higher in groups C and D than in group A and in group D than in group E ( P<0.05), whereas the relative expression of P-β-catenin protein was significantly lower in groups C and D than in group A and in group D than in group E ( P<0.05).
CONCLUSION
Different from EGF, bFGF can induce neural differentiation of hBMSCs. In addition, EGF can enhance the hBMSCs neural differentiation of bFGF, while the Wnt/β-catenin signaling pathway may play a positive regulatory role in these processes.
Humans
;
beta Catenin/metabolism*
;
Bone Marrow Cells
;
Cell Differentiation
;
Cells, Cultured
;
Epidermal Growth Factor/metabolism*
;
Mesenchymal Stem Cells
;
Wnt Signaling Pathway
;
Neurons
;
Fibroblast Growth Factor 2/metabolism*
4.Research on Runx2 gene induced differentiation of human amniotic mesenchymal stem cells into ligament fibroblasts in vitro and promotion of tendon-bone healing in rabbits.
Tao XIE ; Hehe ZHONG ; Ying JIN ; Xiuqi LIU ; Fang CHEN ; Kuan XIANG ; Shuhong WU
Chinese Journal of Reparative and Reconstructive Surgery 2023;37(12):1523-1532
OBJECTIVE:
To investigate whether the Runx2 gene can induce the differentiation of human amniotic mesenchymal stem cells (hAMSCs) to ligament fibroblasts in vitro and promote the tendon-bone healing in rabbits.
METHODS:
hAMSCs were isolated from the placentas voluntarily donated from healthy parturients and passaged, and then identified by flow cytometric identification. Adenoviral vectors carrying Runx2 gene (Ad-Runx2) and empty vector adenovirus (Ad-NC) were constructed and viral titer assay; then, the 3rd generation hAMSCs were transfected with Ad-Runx2 (Ad-Runx2 group) or Ad-NC (Ad-NC group). The real-time fluorescence quantitative PCR and Western blot were used to detect Runx2 gene and protein expression to verify the effectiveness of Ad-Runx2 transfection of hAMSCs; and at 3 and 7 days after transfection, real-time fluorescence quantitative PCR was further used to detect the expressions of ligament fibroblast-related genes [vascular endothelial growth factor (VEGF), collagen type Ⅰ, Fibronectin, and Tenascin-C]. The hAMSCs were used as a blank control group. The hAMSCs, hAMSCs transfected with Ad-NC, and hAMSCs were mixed with Matrigel according to the ratio of 1 : 1 and 1 : 2 to construct the cell-scaffold compound. Cell proliferation was detected by cell counting kit 8 (CCK-8) assay, and the corresponding cell-scaffold compound with better proliferation were taken for subsequent animal experiments. Twelve New Zealand white rabbits were randomly divided into 4 groups of sham operation group (Sham group), anterior cruciate ligament reconstruction group (ACLR group), anterior cruciate ligament reconstruction+hAMSCs transfected with Ad-NC-scaffold compound group (Ad-NC group), and anterior cruciate ligament reconstruction+hAMSCs transfected with Ad-Runx2-scaffold compound group (Ad-Runx2 group), with 3 rabbits in each group. After preparing the ACL reconstruction model, the Ad-NC group and the Ad-Runx2 group injected the optimal hAMSCs-Matrigel compunds into the bone channel correspondingly. The samples were taken for gross, histological (HE staining and sirius red staining), and immunofluorescence staining observation at 1 month after operation to evaluate the inflammatory cell infiltration as well as collagen and Tenascin-C content in the ligament tissues.
RESULTS:
Flow cytometric identification of the isolated cells conformed to the phenotypic characteristics of MSCs. The Runx2 gene was successfully transfected into hAMSCs. Compared with the Ad-NC group, the relative expressions of VEGF and collagen type Ⅰ genes in the Ad-Runx2 group significantly increased at 3 and 7 days after transfection ( P<0.05), Fibronectin significantly increased at 3 days ( P<0.05), and Tenascin-C significantly increased at 3 days and decreased at 7 days ( P<0.05). CCK-8 detection showed that there was no significant difference ( P>0.05) in the cell proliferation between groups and between different time points after mixed culture of two ratios. So the cell-scaffold compound constructed in the ratio of 1∶1 was selected for subsequent experiments. Animal experiments showed that at 1 month after operation, the continuity of the grafted tendon was complete in all groups; HE staining showed that the tissue repair in the Ad-Runx2 group was better and there were fewer inflammatory cells when compared with the ACLR group and the Ad-NC group; sirius red staining and immunofluorescence staining showed that the Ad-Runx2 group had more collagen typeⅠ and Ⅲ fibers, tending to form a normal ACL structure. However, the fluorescence intensity of Tenascin-C protein was weakening when compared to the ACLR and Ad-NC groups.
CONCLUSION
Runx2 gene transfection of hAMSCs induces directed differentiation to ligament fibroblasts and promotes tendon-bone healing in reconstructed anterior cruciate ligament in rabbits.
Pregnancy
;
Female
;
Humans
;
Rabbits
;
Animals
;
Vascular Endothelial Growth Factor A/metabolism*
;
Fibronectins/metabolism*
;
Collagen Type I/genetics*
;
Tenascin/metabolism*
;
Collagen/metabolism*
;
Anterior Cruciate Ligament/surgery*
;
Mesenchymal Stem Cells
;
Tendons/metabolism*
;
Fibroblasts/metabolism*
5.Hydrogel loaded with exosomes from Wharton 's Jelly-derived mesenchymal stem cells enhances wound healing in mice.
Cui Bocheng XU ; Zhengbao XU ; Chengyang YU ; Zufu JIANG
Journal of Zhejiang University. Medical sciences 2023;52(6):766-776
OBJECTIVES:
To explore the effect of hydrogel loaded with exosomes from Wharton's Jelly-derived mesenchymal stem cell (WJMSC) on wound healing.
METHODS:
Exosomes were extracted from WJMSC, and the morphology and size of WJMSC-derived exosomes (WEX) were analyzed by transmission electron microscopy and nanoparticle size analyzer, respectively. The surface markers CD9, CD81, and Calnexin of WEX were detected by Western blotting. Exosome-loaded alginate hydrogel (WEX-gel) was prepared; its morphology was studied by scanning electron microscope, and its rheological behavior was examined by a rheometer. The in vitro drug release performance of WEX-gel was investigated by BCA method. RAW264.7 cells were treated with alginate hydrogel, WEX and WEX-gel, respectively; and the expression of CD86 and CD206 in macrophages was detected by flow cytometry. A full-thickness skin wound model was established in mice; the model mice were randomly divided into blank control group, WEX control group and WEX-gel group, and PBS, WEX and WEX-gel were applied to the wound area of mice, respectively. On day 3, the skin tissue of mice was excised, and the antibacterial effect of WEX hydrogel was evaluated by plate counting. On day 15, the mice were euthanized and the percentage of residual wounds was calculated. The histological changes of the skin wound were observed after hematoxylin and eosin (HE) and Masson stainings. The expression of CD86, CD206, CD31 and vascular endothelial growth factor (VEGF) in the skin wound tissue was detected by immunohistochemistry.
RESULTS:
Exosomes were successfully extracted from WJMSC. WEX-gel presented a regular three-dimensional network structure, good rheology and controlled drug release performance. WEX-gel promoted the polarization of RAW264.7 cells from the M1 phenotype to M2 phenotype in vitro. The residual wound percentage in blank control group, WEX control group and WEX-gel group were (27.5±3.4)%, (15.3±1.2)% and (7.6±1.1)%, respectively (P<0.05). The antibacterial property of WEX-gel is better than that of WEX (P<0.05). The dermis thickness, the number of new hair follicles, and the rate of collagen deposition in the WEX-gel group were significantly higher than those in the other two groups (all P<0.05). The expression of CD206, CD31 and VEGF in skin wound tissue was higher and the expression of CD86 was lower in WEX-gel group than those in other two groups (all P<0.05).
CONCLUSIONS
WEX-gel can significantly promote wound healing in mice by regulating the polarization of macrophages.
Mice
;
Animals
;
Vascular Endothelial Growth Factor A
;
Wharton Jelly
;
Exosomes
;
Hydrogels
;
Wound Healing/physiology*
;
Mesenchymal Stem Cells
;
Anti-Bacterial Agents
;
Alginates
6.The Latest Research Progress of Mesenchymal Stem Cells Derived from Multiple Myeloma Patients --Review.
Xiao-Sui LING ; Hai-Ping HE ; Li-Hua ZHANG ; Fan LI
Journal of Experimental Hematology 2023;31(4):1233-1236
Multiple myeloma (MM) is a malignant proliferative disease of plasma cells. Bone marrow mesenchymal stem cells (MSC) play an important role in the progression of MM. Compared with normal donor derived MSC (ND-MSC), MM patients derived MSC (MM-MSC) exhibit abnormalities in genes, signaling pathways, protein expression levels and cytokines secreted by themselves. Moreover, the exosomes of MM-MSC can interact with the bone marrow microenvironment. The above reasons can lead to MM cell proliferation, chemoresistance, impaired osteogenic differentiation of MM-MSC, and affect the immunomodulatory capacity of MM patients. In order to further understand the pathogenesis and related influencing factors of MM, this paper reviews the latest research progress of MM-MSC.
Humans
;
Multiple Myeloma/pathology*
;
Osteogenesis
;
Mesenchymal Stem Cells
;
Cell Differentiation
;
Bone Marrow/metabolism*
;
Bone Marrow Cells/metabolism*
;
Tumor Microenvironment
7.Recent Progress on Pharmaceutical Properties of Extracellular Vesicles from Mesenchymal Stem Cells--Review.
Yu-Shuang LIU ; Yuan SUN ; Zi-Kuan GUO
Journal of Experimental Hematology 2023;31(4):1247-1251
Mesenchymal stem cells (MSCs) have been officially approved in many countries to treat graft-versus-host disease, autoimmune disorders and those associated with tissue regeneration after hematopoietic stem cell transplantation. Studies in recent years have confirmed that MSC acts mainly through paracrine mechanism, in which extracellular vesicles secreted by MSC (MSC-EV) play a central role. MSC-EV has overwhelming advantages over MSC itself in the setting of adverse effects in clinical application, indicating that MSC-EV might take the place of its parent cells to be a potentially therapeutic tool for "cell-free therapy". The pharmaceutical properties of MSC-EV largely depend upon the practical and optimal techniques including large-scale expansion of MSC, the modification of MSC based on the indications and the in vivo dynamic features of MSC-EV, and the methods for preparing and harvesting large amounts of MSC-EV. The recent progresses on the issues above will be briefly reviewed.
Humans
;
Extracellular Vesicles
;
Hematopoietic Stem Cell Transplantation/adverse effects*
;
Mesenchymal Stem Cell Transplantation/methods*
;
Mesenchymal Stem Cells
;
Pharmaceutical Preparations
8.Effect of Human Bone Marrow Mesenchymal Stem Cells with Ectopic High OCT4 Expression on T Lymphocyte Function.
Xiao-Ping GUO ; Yan-Fei CHEN ; Ping CHEN ; Jin PAN ; Pei-Ting YING ; Ning ZHAO ; Yong-Min TANG
Journal of Experimental Hematology 2023;31(5):1523-1530
OBJECTIVE:
To explore the effect of human bone marrow mesenchymal stem cells (MSCs) with ectopic high OCT4 expression on T-cell proliferation, activation and secretion in vitro.
METHODS:
Peripheral blood mononuclear cells were isolated from healthy children. Anti-CD3 and anti-CD28 monoclonal antibodies were used to activate T lymphocytes, which were stimulated by interleukin (IL)-2 for one week in vitro. Then MSCs with ectopic high OCT4 expression (MSC-OCT4) were co-cultured with activated T lymphocytes. After one week of co-culture, the supernatant was collected and the levels of Th1/Th2 cytokines [IL-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α and interferon (IFN)-γ] were determined by flow cytometry. The lymphocytes after one week of co-culture were collected and counted by Countstar software. After the proportions of activated/inactivated T cell subsets were determined by flow cytometry, the absolute lymphocyte counts were calculated and expressed as mean ± standard deviation.
RESULTS:
Compared with control T cell alone culture group, the proliferation of CD3+ T cells, CD3+CD4+ T cells, and CD3+CD8+ T cells were significantly inhibited in MSC group and MSC-OCT4 group. Compared with MSC, MSC-OCT4 could inhibit CD3+CD8+ T cell proliferation better (P =0.049), and mainly inhibited early T cell activation. Compared with control T cell alone culture group, the levels of IL-2 and INF-γ were significantly down-regulated both in MSC group and MSC-OCT4 group.After co-culture with T cells for one week, the level of IL-6 significantly increased in MSC group and MSC-OCT4 group compared with that before co-culture. Compared with control MSC group, MSC-OCT4 group had higher viable cell numbers after 1 week of co-culture (P =0.019), and could resist the inhibition of proliferation by higher concentration of mitomycin C.
CONCLUSION
Both MSC and MSC-OCT4 can inhibit the proliferation and activation of IL-2-stimulated T cells in vitro. After overexpression of OCT4, MSC has better proliferation ability in vitro and can inhibit the proliferation of CD3+CD8+ T cells more effectively, which may have a better and more lasting immunosuppressive ability to regulate the balance of Th1/Th2.
Child
;
Humans
;
Bone Marrow Cells
;
CD8-Positive T-Lymphocytes/metabolism*
;
Cell Proliferation
;
Cells, Cultured
;
Interleukin-2
;
Interleukin-6/metabolism*
;
Leukocytes, Mononuclear/metabolism*
;
Lymphocyte Activation
;
Mesenchymal Stem Cells
;
Tumor Necrosis Factor-alpha/metabolism*
9.MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1.
Chen ZHANG ; Weilong YE ; Mengyao ZHAO ; Lujue LONG ; Dengsheng XIA ; Zhipeng FAN
International Journal of Oral Science 2023;15(1):48-48
Mesenchymal stem cell (MSC)-based therapy has emerged as a promising treatment for spinal cord injury (SCI), but improving the neurogenic potential of MSCs remains a challenge. Mixed lineage leukemia 1 (MLL1), an H3K4me3 methyltransferases, plays a critical role in regulating lineage-specific gene expression and influences neurogenesis. In this study, we investigated the role and mechanism of MLL1 in the neurogenesis of stem cells from apical papilla (SCAPs). We examined the expression of neural markers, and the nerve repair and regeneration ability of SCAPs using dynamic changes in neuron-like cells, immunofluorescence staining, and a SCI model. We employed a coimmunoprecipitation (Co-IP) assay, real-time RT-PCR, microarray analysis, and chromatin immunoprecipitation (ChIP) assay to investigate the molecular mechanism. The results showed that MLL1 knock-down increased the expression of neural markers, including neurogenic differentiation factor (NeuroD), neural cell adhesion molecule (NCAM), tyrosine hydroxylase (TH), βIII-tubulin and Nestin, and promoted neuron-like cell formation in SCAPs. In vivo, a transplantation experiment showed that depletion of MLL 1 in SCAPs can restore motor function in a rat SCI model. MLL1 can combine with WD repeat domain 5 (WDR5) and WDR5 inhibit the expression of neural markers in SCAPs. MLL1 regulates Hairy and enhancer of split 1 (HES1) expression by directly binds to HES1 promoters via regulating H3K4me3 methylation by interacting with WDR5. Additionally, HES1 enhances the expression of neural markers in SCAPs. Our findings demonstrate that MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1. These results provide a potential therapeutic target for promoting the recovery of motor function in SCI patients.
Animals
;
Humans
;
Rats
;
Cell Differentiation
;
Intracellular Signaling Peptides and Proteins/therapeutic use*
;
Leukemia/metabolism*
;
Mesenchymal Stem Cells
;
Neurogenesis
;
Stem Cells
;
Transcription Factor HES-1/metabolism*
10.Mesenchymal stem cell-derived apoptotic bodies alleviate alveolar bone destruction by regulating osteoclast differentiation and function.
Xiaoyan LI ; Yiyang JIANG ; Xu LIU ; Jingfei FU ; Juan DU ; Zhenhua LUO ; Junji XU ; Ujjal Kumar BHAWAL ; Yi LIU ; Lijia GUO
International Journal of Oral Science 2023;15(1):51-51
Periodontitis is caused by overactive osteoclast activity that results in the loss of periodontal supporting tissue and mesenchymal stem cells (MSCs) are essential for periodontal regeneration. However, the hypoxic periodontal microenvironment during periodontitis induces the apoptosis of MSCs. Apoptotic bodies (ABs) are the major product of apoptotic cells and have been attracting increased attention as potential mediators for periodontitis treatment, thus we investigated the effects of ABs derived from MSCs on periodontitis. MSCs were derived from bone marrows of mice and were cultured under hypoxic conditions for 72 h, after which ABs were isolated from the culture supernatant using a multi-filtration system. The results demonstrate that ABs derived from MSCs inhibited osteoclast differentiation and alveolar bone resorption. miRNA array analysis showed that miR-223-3p is highly enriched in those ABs and is critical for their therapeutic effects. Targetscan and luciferase activity results confirmed that Itgb1 is targeted by miR-223-3p, which interferes with the function of osteoclasts. Additionally, DC-STAMP is a key regulator that mediates membrane infusion. ABs and pre-osteoclasts expressed high levels of DC-STAMP on their membranes, which mediates the engulfment of ABs by pre-osteoclasts. ABs with knock-down of DC-STAMP failed to be engulfed by pre-osteoclasts. Collectively, MSC-derived ABs are targeted to be engulfed by pre-osteoclasts via DC-STAMP, which rescued alveolar bone loss by transferring miR-223-3p to osteoclasts, which in turn led to the attenuation of their differentiation and bone resorption. These results suggest that MSC-derived ABs are promising therapeutic agents for the treatment of periodontitis.
Humans
;
Osteoclasts
;
Alveolar Bone Loss/therapy*
;
Cell Differentiation
;
MicroRNAs
;
Periodontitis/therapy*
;
Extracellular Vesicles
;
Apoptosis
;
Mesenchymal Stem Cells

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