OBJECTIVE: To investigate the effect of human adipose-derived mesenchymal stem cells (hASCs) exosomes on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) extracted from osteoporotic mice, and to evaluate the effect of hASCs exosomes on preventing bone loss induced by estrogen deficiency. METHODS: hASCs exosomes were extracted by ultracentrifugation. The osteoporotic mice were established by bilateral ovariectomy (OVX). BMSCs were isolated from osteo-porotic mice and cultured for further analysis. In the experimental group, these BMSCs were exposed to an osteogenic induction medium supplemented with hASCs exosomes to evaluate their potential effects on osteogenesis. In contrast, the control group was treated with the same osteogenic induction medium, but without the addition of hASCs exosomes, to serve as a baseline comparison for the study. To comprehensively assess the osteogenic differentiation of BMSCs influenced by hASCs exosomes, alkaline phosphatase (ALP) staining, ALP activity quantitative analysis and quantitative reverse transcription polymerase chain reaction (qPCR) were performed. These evaluations provided critical insights into the role of hASCs exosomes in promoting osteoblast differentiation and bone formation in osteoporotic conditions. The fluorescence labeled hASCs exosomes were injected via the tail vein to observe the biodistribution of exosomes. Two weeks after OVX, the mice were divided into three groups: The experimental group consisted of estrogen-deficient mice receiving hASCs exosome injections; the negative control group consisted of estrogen-deficient mice receiving phosphate-buffered saline (PBS) injections; and the positive control group consisted of mice that underwent Sham surgery and received PBS injections.The injections were administered once every 3 days, for a total of 8 injections. Afterward, the femurs were collected from the mice, and micro-computed tomography (micro-CT) was performed to measure bone mineral density and conduct bone morphometric analysis. RESULTS: hASCs exosomes were successfully extracted using ultracentrifugation. After the induction by hASCs exosomes, ALP staining and ALP activity in the BMSCs extracted from osteoporotic mice were significantly enhanced, the expression of osteogenesis related genes in BMSCs were significantly up-regulated. More trabecular bone and higher bone mineral density were observed in estrogen-deficient mice injected with hASCs exosomes compared with estrogen-deficient mice injected with PBS, and there was no significant decrease in bone mineral density compared with the Sham operation group. CONCLUSION hASCs exosomes promoted the osteogenic differentiation of BMSCs extracted from osteoporotic mice. hASCs exosomes prevented bone loss induced by estrogen deficiency.
Animals ; Mesenchymal Stem Cells/cytology* ; Exosomes ; Estrogens/deficiency* ; Humans ; Osteogenesis ; Cell Differentiation ; Female ; Mice ; Osteoporosis/prevention & control* ; Ovariectomy ; Adipose Tissue/cytology* ; Cells, Cultured

OBJECTIVE: To identify the role of gene silencing or overexpression of Nemo-like kinase (NLK) during the process of neural differentiation of human mesenchymal stem cells (hBMSCs), and to explore the effect of NLK downregulation by transfection of small interfering RNA (siRNA) on promoting neuralized tissue engineered bone regeneration. METHODS: NLK-knockdown hBMSCs were established by transfection of siRNA (the experimental group was transfected with siRNA silencing the NLK gene, the control group was transfected with control siRNA and labeled as negative control group), and NLK-overexpression hBMSCs were established using lentivirus vector transfection technique (the experimental group was infected with lentivirus overexpressing the NLK gene, the control group was infected with an empty vector lentivirus and labeled as the empty vector group). After neurogenic induction, quantitative real-time polymerase chain reaction (qPCR) was used to detect the expression of neural-related gene, and Western blot as well as immunofluorescence staining about several specific neural markers were used to evaluate the neural differentiation ability of hBMSCs.6-week-old male nude mice were divided into 4 groups: ① β-tricalcium phosphate (β-TCP) group, ② β-TCP+ osteogenic induced hBMSCs group, ③ β-TCP+ siRNA-negative control (siRNA-NC) transfection hBMSCs group, ④ β-TCP+ siRNA-NLK transfection hBMSCs group. Four weeks after the subcutaneous ectopic osteogenesis models were established, the osteogenesis and neurogenesis were detected by hematoxylin-eosin (HE) staining, Masson staining and tissue immunofluorescence assay. Statistical analysis was conducted by independent sample t test. RESULTS: After gene silencing of NLK by siRNA in hBMSCs, neural-related genes, including the class Ⅲ β-tubulin (TUBB3), microtubule association protein-2 (MAP2), soluble protein-100 (S100), nestin (NES), NG2 proteoglycan (NG2) and calcitonin gene-related peptide (CGRP), were increased significantly in NLK-knockdown hBMSCs compared with the negative control group(P < 0.05), and the expression levels of TUBB3 and MAP2 of the NLK silencing group were also increased. Oppositely, after NLK was overexpressed using lentivirus vector transfection technique, TUBB3, MAP2, S100 and NG2 were significantly decreased in NLK-overexpression hBMSCs compared with the empty vector group (P < 0.05), and the expression level of TUBB3 was also decreased. 4 weeks after the subcutaneous ectopic osteogenesis model was established, more mineralized tissues were formed in the β-TCP+ siRNA-NLK transfection hBMSCs group compared with the other three groups, and the expression of BMP2 and S100 was higher in the β-TCP+ siRNA-NLK transfection hBMSCs group than in the other groups. CONCLUSION Gene silencing of NLK by siRNA promoted the ability of neural differentiation of hBMSCs in vitro and promoted neuralized tissue engineered bone formation in subcutaneous ectopic osteogenic models in vivo in nude mice.
Bone Regeneration/genetics* ; Animals ; Mesenchymal Stem Cells/cytology* ; Humans ; RNA, Small Interfering/genetics* ; Tissue Engineering/methods* ; Cell Differentiation ; Mice, Nude ; Gene Silencing ; Mice ; Male ; Protein Serine-Threonine Kinases/genetics* ; Intracellular Signaling Peptides and Proteins/genetics* ; Transfection ; Cells, Cultured ; Lentivirus/genetics*

OBJECTIVE: To investigate the biocompatibility of porous WE43 magnesium alloy scaffolds manufactured by 3D printing technology and to observe its effect in treating femoral defects in New Zealand white rabbits. METHODS: In vitro cytotoxicity test was performed using bone marrow mesenchymal stem cells from Sprague Dawley (S-D) rats. According to the different culture media, the cells were divided into 100% extract group, 50% extract group, 10% extract group and control group. After culturing for 1, 3 and 7 days, the cell activity of each group was determined by cell counting kit-8 (CCK-8). In the in vivo experiment, 3.0-3.5 kg New Zealand white rabbits were randomly divided into three groups: Experimental group, bone cement group and blank group, with 9 rabbits in each group. Each rabbit underwent surgery on the left lateral femoral condyle, and a bone defect with a diameter of 5 mm and a depth of 6 mm was created using a bone drill. The experimental group was implanted with WE43 magnesium alloy scaffolds, the bone cement group was implanted with calcium sulfate bone cement, and the blank group was not implanted. Then 4, 8 and 12 weeks after surgery, 3 rabbits in each group were euthanized by carbon dioxide anesthesia, and the femur and important internal organs were sampled. Micro-computed tomography (Micro-CT) scanning was performed on the left lateral femoral condyle. Sections of important internal organs were prepared and stained with hematoxylin-eosin (HE). Hard tissue sections were made from the left lateral femoral condyle and stained with methylene blue acid fuchsin and observed under a microscope. RESULTS: In the cytotoxicity test, the cell survival rate in the 100% extract group was higher than that in the control group (140.56% vs. 100.00%, P < 0.05) on 1 day of culture; there was no statistically significant difference (P>0.05) in cell survival rate among the groups on 3 days of culture; the cell survival rate in the 100% extract group was lower than that in the control group (68.64% vs. 100.00%, P < 0.05) on 7 days of culture. Micro-CT scanning in the in vivo experiment found that most of the scaffolds in the experimental group had been degraded in 4 weeks, with very few high-density scaffolds remaining. In 12 weeks, there was no obvious stent outline. In 4 weeks, a certain amount of gas was generated around the WE43 magnesium alloy scaffold, and the gas was significantly reduced from 8 to 12 weeks. Hard tissue sections showed that a certain amount of extracellular matrix and osteoid were generated around the scaffolds in the experimental group in 4 weeks. In the bone cement group, most of the calcium sulfate bone cement had been degraded. In 8 weeks, the osteoid around the scaffold and its degradation products in the experimental group increased significantly. In 12 weeks, new bone was in contact with the scaffold around the scaffold in the experimental group. There was less new bone in the bone cement group and the blank group. CONCLUSION The porous WE43 magnesium alloy scaffold fabricated by 3D printing process has good biocompatibility and good osteogenic properties, and has the potential to become a new material for repairing bone defects.
Animals ; Rabbits ; Printing, Three-Dimensional ; Alloys/chemistry* ; Tissue Scaffolds/chemistry* ; Magnesium/chemistry* ; Rats, Sprague-Dawley ; Biocompatible Materials ; Mesenchymal Stem Cells/cytology* ; Femur/surgery* ; Rats ; Absorbable Implants ; Male ; Bone Regeneration ; Tissue Engineering/methods* ; Cells, Cultured

Adipose tissue-derived mesenchymal stem cells (ADSCs) are crucially involved in various biological processes because of their self-renewal, multi-differentiation, and immunomodulatory activities. Some ADSC's characteristics have been associated with the basic theory of Chinese medicine (CM), especially the Meridian theory. CM can improve the biological properties of ADSCs to facilitate their use in injury treatment, restore immune homeostasis, and inhibit inflammatory responses. Therefore, the combination of CM and ADSCs may be a new promising research direction in integrative medicine of China. This review summarizes the association between CM and ADSCs to assess the potential application value of their combination against various diseases.
Mesenchymal Stem Cells/cytology* ; Adipose Tissue/cytology* ; Humans ; Medicine, Chinese Traditional ; Integrative Medicine ; Animals

OBJECTIVE: To investigate the Wnt signaling pathway and miRNAs mechanism of extracts of Plastrum Testudinis (PT) in the treatment of osteoporosis (OP). METHODS: Thirty female Sprague Dawley rats were randomly divided into 5 groups by random number table method, including sham group, ovariectomized group (OVX), ovariectomized groups treated with high-, medium-, and low-dose PT (160, 80, 40 mg/kg per day, respectively), with 6 rats in each group. Except for the sham group, the other rats underwent bilateral ovariectomy to simulate OP and received PT by oral gavage for 10 consecutive weeks. After treatment, bone mineral density was measured by dual-energy X-ray absorptiometry; bone microstructure was analyzed by micro-computed tomography and hematoxylin and eosin staining; and the expressions of osteogenic differentiation-related factors were detected by immunochemistry, Western blot, and quantitative polymerase chain reaction. In addition, Dickkopf-1 (Dkk-1) was used to inhibit the Wnt signaling pathway in bone marrow mesenchymal stem cells (BMSCs) and miRNA overexpression was used to evaluate the effect of miR-214 on the osteogenic differentiation of BMSCs. Subsequently, PT extract was used to rescue the effects of Dkk-1 and miR-214, and its impacts on the osteogenic differentiation-related factors of BMSCs were evaluated. RESULTS: PT-M and PT-L significantly reduced the weight gain in OVX rats (P<0.05). PT also regulated the bone mass and bone microarchitecture of the femur in OVX rats, and increased the expressions of bone formation-related factors including alkaline phosphatase, bone morphogenetic protein type 2, collagen type I alpha 1, and runt-related transcription factor 2 when compared with the OVX group (P<0.05 or P<0.01). Meanwhile, different doses of PT significantly rescued the inhibition of Wnt signaling pathway-related factors in OVX rats, and increased the mRNA or protein expressions of Wnt3a, β-catenin, glycogen synthase kinase-3β, and low-density lipoprotein receptor-related protein 5 (P<0.05 or P<0.01). PT stimulated the osteogenic differentiation of BMSCs inhibited by Dkk-1 and activated the Wnt signaling pathway. In addition, the expression of miR-214 was decreased in OVX rats (P<0.01), and it was negatively correlated with the osteogenic differentiation of BMSCs (P<0.01). MiR-214 mimic inhibited Wnt signaling pathway in BMSCs (P<0.05 or P<0.01). Conversely, PT effectively counteracted the effect of miR-214 mimic, thereby activating the Wnt signaling pathway and stimulating osteogenic differentiation in BMSCs (P<0.05 or P<0.01). CONCLUSION PT stimulates bone formation in OVX rats through β-catenin-mediated Wnt signaling pathway, which may be related to inhibiting miR-214 in BMSCs.
Animals ; MicroRNAs/genetics* ; Female ; Rats, Sprague-Dawley ; Wnt Signaling Pathway/genetics* ; Osteogenesis/genetics* ; Mesenchymal Stem Cells/cytology* ; Cell Differentiation/drug effects* ; Bone Density/drug effects* ; Ovariectomy ; Osteoporosis/drug therapy* ; beta Catenin/metabolism* ; Rats ; Intercellular Signaling Peptides and Proteins/metabolism* ; Drugs, Chinese Herbal/pharmacology*

Meniscus injuries are widespread and the available treatments do not offer enough healing potential. Here, we provide critical support for using pigs as a biological model for meniscal degeneration and the development of cutting-edge therapies in orthopedics. We present a single-cell transcriptome atlas of the meniscus, consisting of cell clusters corresponding to four major cell types: chondrocytes, endothelial cells, smooth muscle cells, and immune cells. Five distinct chondrocyte subclusters (CH0‒CH4) were annotated, of which only one was widespread in both the red and white zones, indicating a major difference in the cellular makeup of the zones. Subclusters distinct to the white zone appear responsible for cartilage-specific matrix deposition and protection against adverse microenvironmental factors, while those in the red zone exhibit characteristics of mesenchymal stem cells and are more likely to proliferate and migrate. Additionally, they induce remodeling actions in other chondrocyte subclusters and promote the proliferation and maturation of endothelial cells, inducing healing and vascularization processes. Considering that they have substantial remodeling capabilities, these subclusters should be of great interest for tissue engineering studies. We also show that the cellular makeup of the pig meniscus is comparable to that of humans, which supports the use of pigs as a model in orthopedic therapy development.
Animals ; Swine ; Chondrocytes/physiology* ; Single-Cell Analysis ; Meniscus/blood supply* ; Endothelial Cells/cytology* ; Transcriptome ; Mesenchymal Stem Cells/cytology* ; Neovascularization, Physiologic ; Cell Proliferation

Periodontitis is a common oral disease caused by bacteria coupled with an excessive host immune response. Stem cell therapy can be a promising treatment strategy for periodontitis, but the relevant mechanism is complicated. This study aimed to explore the therapeutic potential of mitochondria from human embryonic stem cell-derived mesenchymal stem cells (hESC-MSCs) for the treatment of periodontitis. The gingival tissues of periodontitis patients are characterized by abnormal mitochondrial structure. Human gingival fibroblasts (HGFs) were exposed to 5 μg/mL lipopolysaccharide (LPS) for 24 h to establish a cell injury model. When treated with hESC-MSCs or mitochondria derived from hESC-MSCs, HGFs showed reduced expression of inflammatory genes, increased adenosine triphosphate (ATP) level, decreased reactive oxygen species (ROS) production, and enhanced mitochondrial function compared to the control. The average efficiency of isolated mitochondrial transfer by hESC-MSCs was determined to be 8.93%. Besides, a therapy of local mitochondrial injection in mice with LPS-induced periodontitis showed a reduction in inflammatory gene expression, as well as an increase in both the mitochondrial number and the aspect ratio in gingival tissues. In conclusion, our results indicate that mitochondria derived from hESC-MSCs can reduce the inflammatory response and improve mitochondrial function in HGFs, suggesting that the transfer of mitochondria between hESC-MSCs and HGFs serves as a potential mechanism underlying the therapeutic effect of stem cells.
Humans ; Gingiva/cytology* ; Fibroblasts/metabolism* ; Mitochondria/physiology* ; Mesenchymal Stem Cells/cytology* ; Animals ; Periodontitis/therapy* ; Mice ; Reactive Oxygen Species/metabolism* ; Inflammation ; Lipopolysaccharides ; Human Embryonic Stem Cells/cytology* ; Cells, Cultured ; Adenosine Triphosphate/metabolism* ; Male

OBJECTIVES: To explore the mechanism by which Tougu Xiaotong Capsule (TXC) promotes chondrogenic differentiation and cartilage repair in mice with osteoarthritis (OA). METHODS: Fifty 8-week-old male C57BL mice were randomly divided into normal control group, cartilage damage (induced by subchondral ring-shaped drilling) model group and TXC treatment groups at low, moderate and high doses (184, 368 and 736 mg/kg, respectively). Saline (in normal control and model groups) and TXC were administered after modeling by daily gavage for 6 consecutive weeks. The changes of cartilage damage in the mice were assessed by measuring thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) and using micro-CT, modified safranine O and fast green staining, HE staining, and qPCR. Primary cultures of mouse synovial mesenchymal stem cells (SMSCs) with lentivirus vector transfection for interfering CXCL12, TXC treatment, or both for 24 h were examined for chondrogenic differentiation using immunofluorescence staining, scratch assay, immunocytochemistry, and Western blotting. RESULTS: In mouse models with cartilage damage, TXC treatment at the moderate dose significantly alleviated joint pain, promoted cartilage repair, and upregulated the mRNA expression levels of CXCL12, GDF5, collagen II, aggrecan, Comp and Sox9 in the cartilage tissue. In primary mouse SMSCs, CXCL12 knockdown resulted in significant reduction of GDF5 protein expression, migration ability and Sox9 protein expression, and these changes were obviously reversed by TXC treatment. CONCLUSIONS TXC promotes chondrogenic differentiation of mouse SMSCs to promote repair of cartilage damage in mice by activating the CXCL12/GDF5 pathway.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Osteoarthritis/metabolism* ; Male ; Growth Differentiation Factor 5/metabolism* ; Mice, Inbred C57BL ; Mice ; Chemokine CXCL12/metabolism* ; Signal Transduction/drug effects* ; Cell Differentiation/drug effects* ; Cartilage, Articular/drug effects* ; Mesenchymal Stem Cells/cytology*

OBJECTIVES: To investigate the mechanism by which chitosan (CS) hydrogel loaded with human umbilical cord mesenchymal stem cell (HUVECs)-derived exosomes (hUCMSC-exos) (Exos@CS-Gel) improves diabetic wound healing. METHODS: hUCMSC-exos were extracted and Exos@CS-Gel was prepared. The effect of Exos@CS-Gel on proliferation and migration of HUVECs were evaluated using scratch wound assay and CCK-8 assay. Diabetic rat models with full-thickness skin wounds established by streptozotocin induction were randomized divided into 4 groups for treatment with Exos@CS-Gel (100 µg hUCMSC-exos dissolved in 100 µL 24% CS hydrogel), hUCMSC-exos (100 µg hUCMSC-exos dissolved in 100 µL PBS), CS hydrogel (100 µL 24% CS hydrogel), or PBS (control group). Wound healing and the therapeutic mechanisms were assessed using immunohistochemistry, HE staining, immunofluorescence, and qRT-PCR. RESULTS: In cultured HUVECs, Exos@CS-Gel treatment significantly promoted cell proliferation and migration. In the rat models of chronic diabetic wounds, the wound healing rate in Exos@CS-Gel group reached 92.7% on day 14, significantly higher than those in hUCMSC-exos group (9.12%), CS hydrogel group (16.28%), and control group (25.98%). Microvessel density and the expression levels of vascular endothelial growth factor and transforming growth factor β-1 were significantly increased in the Exos@CS-Gel group. CONCLUSIONS Exos@CS-Gel promotes survival capacity of hUCMSC-exos in vitro and accelerates diabetic wound healing in rats by promoting angiogenesis and cell proliferation.
Animals ; Wound Healing ; Humans ; Chitosan ; Exosomes ; Mesenchymal Stem Cells/cytology* ; Diabetes Mellitus, Experimental ; Rats ; Umbilical Cord/cytology* ; Hydrogels ; Human Umbilical Vein Endothelial Cells ; Cell Proliferation ; Rats, Sprague-Dawley ; Male

METHODS: Cardiac organoids derived from the self-assembled human induced pluripotent stem cells were constructed by regulating the Wnt signaling pathway. Flow cytometry was used to detect the proportion of cardiomyocytes in the cardiac organoids, and RT-qPCR was employed to detect the mRNA expressions. Immunofluorescence staining was used to detect the protein expressions of TNNT2, CD31, and vimentin. The beating amplitude of the cardiac organoids was determined with calcium transient. In vitro myocardial injury models and ischemia-reperfusion models were established, and the cell injuries were examined using Masson staining. TUNEL staining and calcium transient detection were used to evaluate the adverse effects of doxorubicin and trastuzumab in the cardiac organoids. RESULTS: The cardiac organoids began to beat on the 8th day of culture and consisted of 32.4% cardiomyocytes with high expressions of the myocardial markers TNNT2, NKX2.5, RYR2 and KCNJ2. No significant differences in morphological size, beating frequency, proportion of cardiomyocytes, or myocardial contractility were observed in the cardiac organoids differentiated from different batches. These cardiac organoids could be maintained in in vitro culture conditions for at least 50 days. Captopril treatment could obviously alleviate liquid nitrogen-induced myocardial injury in the cardiac organoids. Hypoxia/reoxygenation induced ischemia-reperfusion injury and promoted myocardial fibrosis and apoptosis in the cardiac organoids. Treatment with doxorubicin for 24 h resulted in significantly increased cell death and reduced beating frequency and cell viability in the cardiac organoids in a dose-dependent manner. Trastuzumab significantly impaired the contractile and calcium handling abilities of the cardiac organoids. CONCLUSIONS Cardiac organoids derived from human induced pluripotent stem cells have been successfully constructed and can be used for cardiac disease modeling and drug evaluation.
Humans ; Induced Pluripotent Stem Cells/cytology* ; Organoids/cytology* ; Myocytes, Cardiac/cytology* ; Cell Differentiation ; Heart Diseases