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 / 中国修复重建外科杂志

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.

In vitro construction of human amniotic mesenchymal stem cell sheet and its osteogenic differentiation / 中国组织工程研究

BACKGROUND: Human amniotic mesenchymal stem cells (hAMSCs) are a kind of adult stem cells that can be extracted from discarded placenta. Compared with other mesenchymal stem cells, hAMSCs have many advantages such as noninvasive isolation, low immunogenicity and short growth cycle, and thus hAMSCs are an important source of tissue engineering seed cells. Currently, hAMSCs have been applied in the clinical treatment of diabetes. OBJECTIVE: To explore a simple method to fabricate hAMSC sheets and to study their potential to differentiate into osteocytes. METHODS: Passage 3 hAMSCs were seeded into culture plates at a high density, and the sheet-forming medium was added to fabricate hAMSC sheet. The structural characteristics of hAMSC sheets were evaluated by histological staining and scanning electron microscopy. The sheet-forming induction medium was added to the passage 3 hAMSCs for 7 continuous days, and then replaced by the osteogenic induction medium for 14 days to construct osteogenic-induced hAMSC sheets. The potential for osteogenic differentiation of hAMSC sheets was assessed by alizarin red staining, immunohistochemical staining, alkaline phosphatase activity, RT-PCR, and western blot assay. RESULTS AND CONCLUSION: Hematoxylin-eosin staining results indicated that hAMSC sheets had a multi-layered structure with the cells stacked layer-by-layer and evenly distributed. Under the scanning electron microscope, the hAMSC sheets had a multi-layered structure, and a large amount of extracellular matrices that enveloped the fusiform cells were produced. After 14 days of osteogenic induction, orange-red precipitation was observed by alizarin red staining. Immunohistochemical staining results showed a large amount of type II collagen. Compared with non-induced hAMSC sheet, alkaline phosphatase activity was significantly increased in the osteogenic induced sheet (P < 0.01). The expression levels of type I collagen, osteocalcin, and Runt-related transcript factor 2 mRNA and protein were significantly higher in the osteogenic-induced hAMSC sheet group than the non-induced hAMSC sheet group (P < 0.05). Our findings indicate that this is a simple and economic method to construct the hAMSC sheets in the normal culture medium. Moreover, hAMSC sheets have a good osteogenic differentiation potential that has been confirmed in vitro.

Scleraxis lentivirus-transfected human amniotic mesenchymal stem cells promote tendon-bone healing in Rabbits / 中国组织工程研究

BACKGROUND: Human amniotic mesenchymal stem cells have a wide variety of sources, low immunogenicity, and multilineage differentiation potential. Studies have confirmed that Scleraxis gene can induce human amniotic mesenchymal stem cells to differentiate into ligaments and accelerate tendon-bone healing. OBJECTIVE: To explore whether Scleraxis induces human amniotic mesenchymal stem cells to promote tendon-bone healing in vivo in rabbits, providing new options for clinical treatment of tendon-bone healing. METHODS: The study protocol was approved by the Ethic Committee of the Affiliated Hospital of Zunyi Medical University, and written informed consent was obtained from each puerpera. The healthy full-term maternal placenta was taken and cultured, and human amniotic mesenchymal stem cells were isolated and cultured by trypsin digestion twice. Then the morphology of the cells was observed under an inverted microscope, and the cells were further cultured until the third generation for subsequent experiments. The lentivirus carrying the Scleraxis gene was transfected into human amniotic mesenchymal stem cells in vitro. Expression levels of ligament-related genes were detected by real-time fluorescent quantitative PCR, and the expression levels of related proteins were detected by immunofluorescence. Human amniotic mesenchymal stem cells transfected with Scleraxis gene were injected into the extraarticular tendon-bone model of rats. After 3 months, specimens were taken to observe the tendon-bone healing. RESULTS AND CONCLUSION: (1) Human amniotic mesenchymal stem cells from passage to third generation showed long fusiform and vortex-like adherent growth under the inverted phase contrast microscope. (2) The third-generation human amniotic mesenchymal stem cells expressed green fluorescence after 24 hours of infection with the Scleraxis gene lentivirus, and the fluorescence expression was strong and stable. (3) Cell counting kit-8 findings indicated that lentivirus transfection of Scleraxis gene showed no influence on the cell growth rate. (4) Real-time fluorescent quantitative PCR findings showed that the mRNA expression of Scleraxis and ligament-related genes type I collagen, type III collagen, Fibronectin and Tenascin-C was significantly increased after lentivirus transfection of Scleraxis gene. (5) The results of immunofluorescence showed that the expression levels of ligament-related proteins type I collagen, type III collagen, Fibronectin and Tenascin-C were increased after lentivirus transfection of Scleraxis gene. To conclude, in vivo animal experiments have confirmed that the lentivirus transfection of Scleraxis gene can accelerate the tendon-bone healing of the rabbit extraarticular tendon-bone model.

Effects of hypoxia-inducible factor 1α on hypoxic tolerance of human amniotic mesenchymal stem cells / 中国修复重建外科杂志

Objective: Under hypoxic conditions, the survival and apoptosis of human amniotic mesenchymal stem cells (hAMSCs) were observed by transient transfection of hypoxia-inducible factor 1α (HIF-1α) gene, to investigate the effect of HIF-1α on hypoxic tolerance of hAMSCs.

Varied therapeutic effects of Human Amniotic Mesenchymal Stem Cell Transplantation with Different Transplantation Methods for Spinal Cord Injury Therapy in Rats / 实用医学杂志

Objective To compare the therapeutic effects of orthotopic injection and tail vein injection of human amniotic mesenchymal stem cells(hAMSCs)on histological restoration and neurological functions of rats with spinal cord injury. Methods Transected spinal cord injury model in rats was established by transplanting DAPI prelabelled hAMSCs one week after injury.BBB scores were used to evaluate the hindlimb movement of rats. The histological patterns.and morphology of medullary sheath of spinal cord were observed. Results BBB scores in the orthotopic injection group and tail vein injection group were increased gradually from one to six week after hAM-SCs transplantation and reached 6.5 ± 0.5 and 7.12 ± 1.61 respectively 6 weeks after cell transplantation,higher than that of the control group(both P < 0.01). However,there was no statistical significance between the two groups.Histological results indicated that the repair of injured tissue in the orthotopic injection group and tail vein injection group were both better than that in the control group,and there were more vesica and loosened layers forming in the injured spinal cord of rats in the PBS control group as compared with the orthotopic and tail vein transplantation group. Conclusion hAMSCs transplantation through tail vein injection could promote histological restoration and neurological regeneration of rats with spinal cord injury,which has the similar therapeutic effects with hAMSCs orthotopic transplantation.

In vivo tracing of human amniotic mesenchymal stem cells labeled with PKH26 in rat intrauterine adhesions model / 生物工程学报

To observe the migration of human amniotic mesenchymal stem cells (hAMSCs) labeled with PKH26 in the endometrium of rats intrauterine adhesion. hAMSCs were isolated, identified and labeled with PKH26 to detect the biological characteristics of the cells. Rat intrauterine adhesion models were established using mechanical and infective method and PKH26-labeled hAMSCs were transplanted through the tail vein. The distribution of PKH26 labeled hAMSCs in the endometrium of rats were observed with the fluorescence confocal microscope. The results showed that PKH26 stain had no significant effect on cell activity, cycle, apoptosis and so on. PKH26-labeled positive cells were mainly distributed in injured endometrium of rats. It shows that the PKH26 labeling technique is a safe and effective method for tracing the human amniotic mesenchymal stem cells in the treatment of intrauterine adhesions.

Propofol intervention on mesenchymal stem cell transplantation on brain injury in rats between Human amniotic / 中国生化药物杂志

Objective Human amniotic mesenchymal stem cells (AM-MSCs) transplantation and to investigate the effect of propofol treatment, recovery of brain injury in rats. Methods 80 SD rats, male and female, weight 300-350 g. Human amniotic mesenchymal stem cells cultured in vitro and recovery (CM-Dil) before transplantation standby. The fluid percussion brain injury device, give 2.5-3.0 ATM hydraulic impact, severe fluid percussion brain injury model was made. After injury 6h give corresponding treatment which were randomly divided into 4 groups: injury group (medium injection group), AM-MSCs transplantation group and propofol group, AM-MSCs + propofol group. The number of positive cells in each group was observed under the fluorescence microscope using CM-Dil markers. 4 weeks after transplantation, 6 rats were randomly executed, and RT-PCR and Blot Western were used to detect the changes of GAP-43, AQP4 gene expression and protein synthesis in brain tissues. After transplantation, 24 h, 3 days and 1, 2, 3, 4 weeks for animal neurological deficit score, in 4 weeks after transplantation of Morris water maze (Morris Water Maze, MWM) test. They were killed after four weeks by immunohistochemistry, HE staining. Results Number of CM-DIL positive cell was the most in AM-MSCs + propofol group, which was in propofol group and AM-MSCs transplantation group were lower than that in the AM-MSCs + propofol group, which in injury group was the least, and the differences among the groups had statistically significant (P<0.05). 4 weeks after transplantation, AQP4 and its mRNA expression of brain damage surrounding tissue in injury group were higher than those in AM-MSCs transplantation group and propofol group; which in AM-MSCs transplantation group and propofol group was higher than those in AM-MSCs + propofol group (P< 0.05); GAP-43 protein and mRNA expression in injury group were lower than those in AM-MSCs transplantation group and propofol group, which in AM-MSCs transplantation group and propofol group were lower than those in AM-MSCs + propofol group (P<0.05). 1 weeks after transplantation, rat nerve dysfunction score in AM-MSCs + propofol group was lower than that in propofol group and AM-MSCs transplantation group; which in propofol group and AM-MSCs transplantation group was lower than that in the control group (P<0.05). The times of crossing platform in AM-MSCs + propofol group was higher than that in propofol group and AM-MSCs transplantation group, significantly higher than that in the injury group (P<0.01). The pathological section was observed 4 weeks after injury, there was no axonal passage in the injury group. In propofol group and AM-MSCs transplantation group, a few axonal like structures were observed, more axonal like structures were observed in AM-MSCs + propofol group. Conclusion Propofol combined with human amniotic mesenchymal stem cells transplantation can significantly improve the neurological function of rats with brain injury.

Synergistic effect of acupuncture and human amniotic mesenchymal stem cell transplantation on the treatment of osteoporosis in ovariectomized rats / 中国比较医学杂志

Objective To investigate the effect of acupuncture combined with human amniotic mesenchymal stem cells ( HAMCs ) transplantation on the osteoporosis in ovariectomized rats.Methods Forty-five healthy female non-pregnant Wistar rats were randomly divided into sham operated group, model group and experimental group ( acupuncture+HAMC transplantation), 15 rats in each group.At 7 days after the surgical wound healing, the rats received acupuncture every day and intravenous injection of HAMCs suspension ( except the sham operated group) once a week for consecutive 12 weeks.The body weight was measured every week.24 hours after the last intervention, the rats were killed and specimens were collected.Specimens of the mid-, proximal-and distal femur were taken to measure the bone mineral density using a dual energy X-ray absorptiometer.At 12 weeks after the intervention, changes of the expression of serum 25-hydroxy-vitamin D (25-HVD), C-terminal peptide of type I collagen (CTX-I), bone specific alkaline phosphatase ( BAP) and human tartrate-resistant acid phosphatase 5b ( TRACP 5b) were determined by ELISA, the biomechanical properties of the removed femur was measured, and the expression of transforming growth factor-β( TGF-β) in the vertebrae was assessed by RT-PCR assay.Results Body weight of rats in the sham operation group was increased gradually in accordance with the natural growth of animals, that of the model group was significantly higher than that of the sham operated group since two months after modeling, and the body weight of the experimental group was similar to that of the sham operated group.The bone mineral density and calcium content of the model group were significantly decreased compared with that of the sham operated group ( P<0.05) , and the bone mineral density and bone calcium content of the experimental group were significantly higher than that of the model group ( P <0.05 ) .The ELISA showed that the expressions of serum 25-HVD, CTX I, BAP, and TRAP5b in the model group were significantly lower than that of the sham operated group, and those of the experimental group were significantly higher than that of the model group ( P<0.05 ) . Measurement of biomechanical properties showed that the limit load, limit stress and elastic modulus of the femur of the sham operated group were significantly higher than that of the model group ( P<0.05 ) , and the limit load and elastic modulus of the experimental group were significantly higher than that of the sham operated group ( P <0.05 ) .T-PCR showed that the expression of TGF-β1 m-RNA in the experimental group was significantly up-regulated than that of the sham operated and model groups ( P<0.05) .Conclusions Acupuncture combined with human amniotic mesenchymal stem cell ( HAMCs) transplantation has a synergistic effect on the treatment of osteoporosis, and can improve the conditions in ovariectomized rats.

Therapeutic effect and immunologic regulation of human amniotic mesenchymal stem cells in rats with experimental type 1 diabetes mellitus / 中华内分泌代谢杂志

Objective To study the therapeutic effect and immunologic regulation of human amniotic mesenchymal stem cells (hAMSCs) in rats with experimental type 1 diabetes mellitus (T1DM).Methods The hAMSCs from human amnion were isolated and cultured in vitro,then phenotype was analyzed by flow cytometry.T1DM were produced by administering streptozocin to rats.The rats were divided into normal control group (n =6),T1 DM model group (n =6),medium treated group (n =6),hAMSCs transplanted group(n =6),and insulin treated group(n =6).5 × 106of hAMSCs or vehicle were administered to rats via sublingual vein.Blood glucose levels of rats were recorded weekly in the groups for six weeks by Blood Sugar Meter.At the end of 6 weeks after hAMSCs transplantation,concentrations of plasma insulin were detected by ELISA; histopathological changes of pancreas,surviwl and differentiation of transplanted hAMSCs in pancreatic tissue were studied with HE staining,and immunofluorescence staining; percentages of lymphocyte subsets in peripheral blood mononuclear cells were determined by flow cytometry ; concentrations of plasma cytokines were determined by cytometric bead array.Results After hAMSCs transplantation,blood glucose levels in rats with T1DM were decreased (P ＜ 0.01),while concentrations of plasma insulin were increased significantly (P＜0.01).At 6 weeks,cell-treated animals showed an improvement in pancreas damage ; the percentages of CD4 + IFN-γ+ (Th 1) and C D4 + interleukin (IL)-17 + (Th 17) cells were reduced (all P＜0.05),while the percentages of FoxP3-positive regulatory T cells (FoxP3 +Treg) and CD4+ IL-4+(Th2) cells were increased (all P＜0.01) ; plasma concentrations of interferon-γ,IL-2,and tumor necrosis factor-αwere decreased (all P＜0.01),but IL-4 level was increased (P＜0.05).No histological evidence of insulin producing cells from hAMSCs was seen within pancreas.Conclusions hAMSCs may reduce blood glucose and alleviate the islet damage in rats with T1 DM,which is related to their potential to up-regulate FoxP3 +Treg cells.

Effects of preconditioning with phosphodiesterase-5 inhibitor on the Biological Properties of human amniotic mesenchymal stem cells / 实用医学杂志

Objective To investigate the biological properties of human amniotic mesenchymal stem cells (hAMSCs) which were preconditioned with phosphodiesterase-5 inhibitor (Vardenfil). Methods hAMSCs were in vitro isolated and cultured, hAMSCs were pre-treated with vardenfil in final concentration of 10 μmol/L. The morphology of Vard-hAMSCs was observed, and the immunological characteristics, proliferative capacity, and ability of anti-oxidative damage of hAMSCs and Vard-hAMSCs were analyzed by flow cytometry. Double labeling immunofluorescent staining was used to count the differences of differential potential between neural cells of hAMSCs and Vard-hAMSCs. Results (1)Flow cytometry revealed that both hAMSCs and Vard-hAMSCs positively expressed CD90、CD105 and CD73, and negatively expressed CD34、CD45、CD11b and HLA-DR. The SPF and PI in Vard-hAMSCs group were (0.57 ± 0.40)% and (2.20 ± 1.60)% respectively, there was no statistical significance compared with hAMSCs group; (2)After 4 hours treated by H2O2, the apoptosis rate in Vard-hAMSCs group were (7.67 ± 0.82)%,which were markedly lower than that in the hAMSCs group and specific blocker group; (3)Under the same induction condition, positive rates of MAP-2 and GFAP in Vard-hAMSCs group were (49.8 ± 6.42)%and (55.2 ± 6.10)% respectively detected by double labeling immunofluorescent staining, which were significantly higher than the control group. Conclusion The strategy that hAMSCs are treated with vandenfil can enrich the ability of anti-oxidative damage and the differential potential for neural cells in a certain time, and the morphology, immunological characteristics, proliferative capacity of Vard-hAMSCs have no significant change. It suggests that pre-treatment with vandenfil may provide a optimized experimental strategey for hAMSCs which were used to treat nervous system disease.