To study the cartilage differentiation of mouse mesenchymal stem cells （MSCs） induced by cartilage-derived morphogenetic proteins-2 in vitro, the MSCs were isolated from mouse bone marrow and cultured in vitro. The ...To study the cartilage differentiation of mouse mesenchymal stem cells （MSCs） induced by cartilage-derived morphogenetic proteins-2 in vitro, the MSCs were isolated from mouse bone marrow and cultured in vitro. The cells in passage 3 were induced into chondrogenic differentiation with different concentrations of recombinant human cartilage-derived morphogenetic proteins-2 （0, 10, 20, 50 and 100 ng/mL）. After 14 days of induction, morphology of cells was observed under phase-contrast microscope. Collagen Ⅱ mRNA and protein were examined with RT-PCR, Western blotting and immunocytochemistry respectively and the sulfate glycosaminoglycan was measured by Alcian blue staining. RT-PCR showed that CDMP-2 could promote expression of collagen Ⅱ mRNA in an dose-dependant manner, especially at the concentration of 50 ng/mL and 100 ng/mL. Immunocytochemistry and Western blotting revealed a similar change. Alcian blue staining exhibited deposition of typical cartilage extracellular matrix. Our results suggest that mouse bone marrow mesencymal stem cells can differentiate into chondrogenic phonotype with the induction of CDMP-2 in vitro, which provides a basis for further research on the role of CDMP-2 in chondrogenesis.展开更多
Cartilage injuries caused by arthritis or trauma pose formidable challenges for effective clinical management due to the limited intrinsic proliferative capability of chondrocytes.Autologous stem cell-based therapies ...Cartilage injuries caused by arthritis or trauma pose formidable challenges for effective clinical management due to the limited intrinsic proliferative capability of chondrocytes.Autologous stem cell-based therapies and transgene-enhanced cartilage tissue engineering may open new avenues for the treatment of cartilage injuries.Bone morphogenetic protein 2(BMP2)induces effective chondrogenesis of mesenchymal stem cells(MSCs)and can thus be explored as a potential therapeutic agent for cartilage defect repair.However,BMP2 also induces robust endochondral ossification.Although the precise mechanisms through which BMP2 governs the divergence of chondrogenesis and osteogenesis remain to be fully understood,blocking endochondral ossification during BMP2-induced cartilage formation may have practical significance for cartilage tissue engineering.Here,we investigate the role of Sox9-donwregulated Smad7 in BMP2-induced chondrogenic differentiation of MSCs.We find that overexpression of Sox9 leads to a decrease in BMP2-induced Smad7 expression in MSCs.Sox9 inhibits BMP2-induced expression of osteopontin while enhancing the expression of chondrogenic marker Col2a1 in MSCs.Forced expression of Sox9 in MSCs promotes BMP2-induced chondrogenesis and suppresses BMP2-induced endochondral ossification.Constitutive Smad7 expression inhibits BMP2-induced chondrogenesis in stem cell implantation assay.Mouse limb explant assay reveals that Sox9 expands BMP2-stimulated chondrocyte proliferating zone while Smad7 promotes BMP2-intitated hypertrophic zone of the growth plate.Cell cycle analysis indicates that Smad7 induces significant early apoptosis in BMP2-stimulated MSCs.Taken together,our results strongly suggest that Sox9 may facilitate BMP2-induced chondrogenesis by downregulating Smad7,which can be exploited for effective cartilage tissue engineering.展开更多
目的:采用血清药理学方法,从基因水平探索中药补肾益肝活血方影响小鼠骨髓基质细胞(BMSCs)成软骨细胞分化的机制。方法:取45只昆明大鼠随机分为3组,补肾益肝活血方高、低剂量组分别以含14.67×4g生药/kg、14.67g生药/kg的水溶液2mL...目的:采用血清药理学方法,从基因水平探索中药补肾益肝活血方影响小鼠骨髓基质细胞(BMSCs)成软骨细胞分化的机制。方法:取45只昆明大鼠随机分为3组,补肾益肝活血方高、低剂量组分别以含14.67×4g生药/kg、14.67g生药/kg的水溶液2mL灌胃,对照组以等量生理盐水2mL灌胃,2次/d,连续给药3d后,腹主动脉采血制备血清。另从4只昆明小鼠骨髓中分离出BMSCs,贴壁法培养传代,取第3代BMSCs分为4组:对照组、阳性组及高、低剂量中药血清诱导组,依次以空白血清、成软骨诱导阳性药及高、低剂量中药血清诱导BMSCs成软骨细胞分化。苏木精-伊红染色观察各组软骨分化情况,基因芯片技术分析成软骨分化基因表达差异谱,并用Real time PCR验证。结果:苏木精-伊红染色显示阳性组及高、低剂量中药血清诱导组均能促进BMSCs成软骨细胞分化。阳性组及高、低剂量中药血清诱导组中软骨细胞相关的金属基质蛋白酶-3(MMP3)、含纤蛋白样表皮生长因子细胞外基质蛋白-1(EFEMPⅠ)均为下调基因(下调倍数>2)。Real time PCR示阳性组及高、低剂量中药血清诱导组中Ⅱ型胶原(CollagenⅡ)、SOX9基因及糖胺聚糖(Aggrecan)的表达均增高,表明三组均有软骨生成,且MMP3、EFEMP1的表达下降,进一步验证了基因芯片结果。结论:补肾益肝活血方含药血清能有效诱导BMSCs成软骨细胞分化,其作用机制很可能与MMP3、EFEMP1介导的通路有关。展开更多
基金This project was supported by a grant from the National Natural Sciences Foundation of China (No 30471753)
文摘To study the cartilage differentiation of mouse mesenchymal stem cells （MSCs） induced by cartilage-derived morphogenetic proteins-2 in vitro, the MSCs were isolated from mouse bone marrow and cultured in vitro. The cells in passage 3 were induced into chondrogenic differentiation with different concentrations of recombinant human cartilage-derived morphogenetic proteins-2 （0, 10, 20, 50 and 100 ng/mL）. After 14 days of induction, morphology of cells was observed under phase-contrast microscope. Collagen Ⅱ mRNA and protein were examined with RT-PCR, Western blotting and immunocytochemistry respectively and the sulfate glycosaminoglycan was measured by Alcian blue staining. RT-PCR showed that CDMP-2 could promote expression of collagen Ⅱ mRNA in an dose-dependant manner, especially at the concentration of 50 ng/mL and 100 ng/mL. Immunocytochemistry and Western blotting revealed a similar change. Alcian blue staining exhibited deposition of typical cartilage extracellular matrix. Our results suggest that mouse bone marrow mesencymal stem cells can differentiate into chondrogenic phonotype with the induction of CDMP-2 in vitro, which provides a basis for further research on the role of CDMP-2 in chondrogenesis.
基金The reported work was supported in part by research grants from the Natural Sciences Foundation of China(#81572142 and#81371972 to WH)the National Institutes of Health(AT004418 to TCH)+4 种基金the U.S.Department of Defense(OR130096 to JMW)the Scoliosis Research Society(TCH and MJL)the 973 Program of the Ministry of Science and Technology of China(#2011CB707906 to TCH)The reported work was also supported in part by The University of Chicago Cancer Center Support Grant(P30CA014599)the National Center for Advancing Translational Sciences of the National Institutes of Health through Grant Number UL1 TR000430.
文摘Cartilage injuries caused by arthritis or trauma pose formidable challenges for effective clinical management due to the limited intrinsic proliferative capability of chondrocytes.Autologous stem cell-based therapies and transgene-enhanced cartilage tissue engineering may open new avenues for the treatment of cartilage injuries.Bone morphogenetic protein 2(BMP2)induces effective chondrogenesis of mesenchymal stem cells(MSCs)and can thus be explored as a potential therapeutic agent for cartilage defect repair.However,BMP2 also induces robust endochondral ossification.Although the precise mechanisms through which BMP2 governs the divergence of chondrogenesis and osteogenesis remain to be fully understood,blocking endochondral ossification during BMP2-induced cartilage formation may have practical significance for cartilage tissue engineering.Here,we investigate the role of Sox9-donwregulated Smad7 in BMP2-induced chondrogenic differentiation of MSCs.We find that overexpression of Sox9 leads to a decrease in BMP2-induced Smad7 expression in MSCs.Sox9 inhibits BMP2-induced expression of osteopontin while enhancing the expression of chondrogenic marker Col2a1 in MSCs.Forced expression of Sox9 in MSCs promotes BMP2-induced chondrogenesis and suppresses BMP2-induced endochondral ossification.Constitutive Smad7 expression inhibits BMP2-induced chondrogenesis in stem cell implantation assay.Mouse limb explant assay reveals that Sox9 expands BMP2-stimulated chondrocyte proliferating zone while Smad7 promotes BMP2-intitated hypertrophic zone of the growth plate.Cell cycle analysis indicates that Smad7 induces significant early apoptosis in BMP2-stimulated MSCs.Taken together,our results strongly suggest that Sox9 may facilitate BMP2-induced chondrogenesis by downregulating Smad7,which can be exploited for effective cartilage tissue engineering.
文摘目的:采用血清药理学方法,从基因水平探索中药补肾益肝活血方影响小鼠骨髓基质细胞(BMSCs)成软骨细胞分化的机制。方法:取45只昆明大鼠随机分为3组,补肾益肝活血方高、低剂量组分别以含14.67×4g生药/kg、14.67g生药/kg的水溶液2mL灌胃,对照组以等量生理盐水2mL灌胃,2次/d,连续给药3d后,腹主动脉采血制备血清。另从4只昆明小鼠骨髓中分离出BMSCs,贴壁法培养传代,取第3代BMSCs分为4组:对照组、阳性组及高、低剂量中药血清诱导组,依次以空白血清、成软骨诱导阳性药及高、低剂量中药血清诱导BMSCs成软骨细胞分化。苏木精-伊红染色观察各组软骨分化情况,基因芯片技术分析成软骨分化基因表达差异谱,并用Real time PCR验证。结果:苏木精-伊红染色显示阳性组及高、低剂量中药血清诱导组均能促进BMSCs成软骨细胞分化。阳性组及高、低剂量中药血清诱导组中软骨细胞相关的金属基质蛋白酶-3(MMP3)、含纤蛋白样表皮生长因子细胞外基质蛋白-1(EFEMPⅠ)均为下调基因(下调倍数>2)。Real time PCR示阳性组及高、低剂量中药血清诱导组中Ⅱ型胶原(CollagenⅡ)、SOX9基因及糖胺聚糖(Aggrecan)的表达均增高,表明三组均有软骨生成,且MMP3、EFEMP1的表达下降,进一步验证了基因芯片结果。结论:补肾益肝活血方含药血清能有效诱导BMSCs成软骨细胞分化,其作用机制很可能与MMP3、EFEMP1介导的通路有关。
