Objective:To investigate the collagen remodeling effect of transplantation mesenchymal stem cells (MSCs) combined with a cardiac-specific expressing human vascular endothelial growth factor-165 (hVEGF165) gene in dilated cardiomyopathy (DCM) animal model. Methods: The bone marrow-derived mesenchymal stem cells of rat were isolated, cultured and expanded ex vivo. The characteristics of those cells were identified by flow cytomery. The subjects were divided into PBS group, MSCs transplantation group (MSCs), gene therapeutic group (GENE), and MSCs transplantation combined with gene transfection group (MSCs-GENE), in which the MSCs and/or pmlc-2v-EGFP-hVEGF165 were injected into the rats' heart. After 1 month, reverse transcriptase PCR (RT-PCR) wasused to detect the mRNA expressions of type I, type III collagen and human transforming growth factor β1 ( TGF-β1). The expressions of hVEGF165 were documented by Western blot. Results; Although the optical densities of TGF-β1 were significantly lower in MSCs-GENE group and GENE group than those in PBS group and MSCs, there were no difference between MSCs-GENEgroup and GENE group (P = 0.910), which suggested the expressions of TGF-β1 were down-regulation in both MSCs-GENE group and GENE group. Comparison of optical density ratio of type I/HI collagen, the optical densities ratios were lower in MSCs-GENE group than that in MSCs group and GENE group, but there was no statistics different (P = 0.172). Though there were expressions of GAPDH in each group, but the expression of hVEGF165 were detected in MSCs-GENE group and GENE group, which suggested the target gene specifically expressing its products in myocardial. Conclusions: The mechanism of cardiac function improved by MSCs with VEGF genes may be related to the down-regulation of TGF-β1 expression, decreasing ratio of type I/III collagen, and increased myocardial compliance and attenuation of remodeling of myocardial collagen lattice.%目的:探讨人血管内皮生长因子165基因(hVEGF165)联合间充质干细胞(mesenchymalstemcells,MSCs)治疗对扩张型心肌病胶原重塑的影响.方法:将40只扩张型心肌病(DCM)大鼠模型随机分为4组:PBS组、MSCs心肌移植联合基因治疗组(MSCs-GENE组)、MSCs心肌移植组(MSCs组)以及基因治疗组(GENE组).心肌局部注射所构建MLC-2v/pIRES2-EG-FP-hVEGF165与MSCs,采用逆转录-聚合酶链反应(RT-PCR)检测Ⅰ型、Ⅲ型胶原和转化生长因子-β(TGF-β)基因表达,蛋白免疫印迹(Westren blot)检测hVEGF165蛋白表达.结果:PBS组、MSCs+ GENE组、MSCs组以及GENE组的Ⅰ型胶原PCR产物灰度比分别为(0.359±0.010)、(0.240±0.012)、(0.313±0.058)、(0.230±0.011);而Ⅲ型胶原分别为(0.831±0.011)、(0.842±0.015)、(0.917±0.058)、(0.688±0.015); TGF-β1分别为(0.548±0.067)、(0.370±0.012)、(0.561±0.014)、(0.369±0.098)；MSCs+ GENE组TGF-β1与GENE组比较差异无统计学意义,但两者显著低于PBS组和MSCs组,提示TGF-β1表达下调；Ⅰ型/Ⅲ型胶原灰度比分别为(0.436±0.072)、(0.290±0.023)、(0.337±0.021)、(0.333±0.011),其中MSCs组与GENE组比较差异无统计学意义；MSCs组与GENE组的Ⅰ型/Ⅲ型胶原灰度比减低,2组比较差异无统计学意义,但MSCs-GENE组进一步使Ⅰ型/Ⅲ型胶原灰度比减低；TGF-β1表达分析结果显示,hVEGF165基因治疗较MSCs移植使TGF-β1表达下调的作用更显著.结论:MSCs移植与hVEGF165基因治疗有可能通过下调TGFβ1表达,降低Ⅰ型/Ⅲ胶原比值,增加心肌顺应性,减轻心肌胶原网络重塑而改善心功能.
展开▼
