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Objective To examine the induction effects of bone marrow mesenchymal stem cells(BMSCs) transfected with bone morphogenetic protein 7 (BMP7) gene differentiating into chondrocytes. Methods We observed the phenotype of cells which were stained with alcian blue and HE climbing to the six pore plate with invert microscope. The glycosaminoglycan (GAG) value in culture medium was detected in control group,BMP7 transfect and culture medium induced groups after 7,14 and 21 days using standard curve method. Standard curve was described using galacturonic-acid as reference substance. The content of collagen Ⅱ was detected by ELISA method. Results HE and Alcian blue staining showed that BMP7 gene transfection group and the group induced by fluid possess the characteristics of chondrocyte. BMP7 induced BMSCs differentiation to chondrocyte which secrete specific protein called collagen Ⅱ and GAG. Content of GAG were (17.1±3.4),(39.5±5.4),(40.8±6.1)mg/L in control group,BMP7 gene transfected group and induced group,collagen Ⅱ were (89.7±14.3),(152.8±14.5),(155.5± 19.3)μg/L in these three groups separately. Comparing with control group,GAG and collagen Ⅱ of BMP7 gene transfected group and culture medium induced group increased obviously(all P < 0.05),but there was no significant difference between BMP7 gene transfeeted group and culture medium induced group (P > 0.05). Conclusion This active protein induces BMSCs differentiating into chondrocyte,in a level similar to that of inducing medium.
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Objective To observe the distribution of bone marrow mesenchymal stem cells(MSCs) and the effects on expression of apoptosis relative proteins Caspase 3 and Bcl-2 after intravenous transplanted into ischemic rat brains.Methods MSCs from SD rats were cultivated and proliferated in vitro and marked with CFSE.MSCs were then intravenously transplanted into middle cerebral artery occlusion(MCAO)models of SD rats.The rats were killed at different time points to observe the distribution of MSCs under fluorescence microscoDe as well as the effects on expression of apoptosis relative proteins Caspase 3 and Bcl-2 using immunohistochemical method.Results Density of Caspase 3 in immunohistochemically positive area in transplantion group were(2.81±0.35)%,(3.98±0.67)%,(5.58±0.92)%,(3.51±0.63)%,(1.64±0.29)%in 6,12,24,72 hours and in 7 days,respectively,and decreased significantly compared with those of control group[(3.92±0.44)%,(5.23±0.30)%,(6.89±0.57)%,(4.39±0.57)%,(2.29±0.21)%],the difference being significant(t=4.37,3.34,2.60,2.32,3.90,P＜0.05 or＜0.01).The density of Bcl-2 in immunohistochemically positive area in transplantation group were(4.70±0.16)%,(5.61±0.26)%,(3.00±0.28)%respectively in 6,12 hours and in 7 days,which had improved significantly compared with those of control group[(3.28±0.27)%,(4.54±0.59)%,(2.15±0.62)%],the difference being significant(t=8.32,3.25,2.54,P＜0.05 or＜0.01).Conclusions Bone marrow MSCs can exert protective effects on brain ischemia and reperfusion injury possibly by down-regulating Caspase 3 and up-regulating Bcl-2.