小鼠骨髓间充质干细胞向平滑肌样细胞分化过程中myocardin的表达

发布时间：2018-08-28 17:27

【摘要】： 背景:平滑肌细胞(SMC)的过度增生是血管病变发生发展中的重要环节。长久以来的观点认为动脉粥样硬化(AS)斑块中的SMC源于中膜SMC的迁移和增生。虽然对于中膜SMC的迁移和增殖的分子机制做了大量的研究工作,但是至今仍没有建立有效的阻止闭塞性血管重建的治疗方法。然而近年来有报道,骨髓细胞参与了血管疾病的发生,发展。研究发现骨髓细胞可能具有分化成血管祖细胞的潜能,这种祖细胞迁移至受损的血管,分化成平滑肌细胞或内皮细胞,参与血管的修复,重塑和病变的形成。这些发现为探索血管疾病的新疗法提供了基础。但是骨髓细胞向平滑肌方向分化的分子机制仍不清楚。然而令人兴奋的是近年来研究者发现了一个关键的促平滑肌分化因子-myocardin。目前对于myocardin的研究仍处于初步阶段。目地:探讨血小板源性生长因子-BB(PDGF-BB)及高浓度的胎牛血清(20%FBS)体外诱导骨髓间充质干细胞(bone marrow mesenchymal stem cell,BMSC)定向分化为平滑肌细胞的可行性及myocardin在此过程中的表达变化。方法:采用全骨髓贴壁分离和消化控制相结合分离小鼠BMSC,然后用PDGF-BB(50μg/L)联合高浓度胎牛血清(20%FBS)诱导BMSC,分别于诱导前及诱导4天、8天后用免疫细胞化学法检测细胞α-SMA,SM-MHC,myocardin的表达,同时在倒置相差显微镜下观察细胞的形态学变化。结果:从单个细胞的形态上看,诱导前BMSC呈梭形,分支状或多边形,诱导后的细胞体积略增加,仍以梭形细胞为主,但是诱导8天时细胞密集处出现束状,漩涡状排列,与SMC相似。细胞免疫组化显示:诱导前及诱导4天、8天时,α-SMA,SM-MHC,myocardin三种蛋白的表达逐渐增强,平均灰度值逐渐降低,不同时间点组组之间统计学比较有显著性差异(P0.05)。结论: PDGF-BB联合高浓度的胎牛血清(20%FBS)可有效诱导BMSC向平滑肌样细胞分化。myocardin在此分化过程中起重要作用。
[Abstract]:Background: the excessive proliferation of (SMC) in smooth muscle cells is an important link in the development of vascular diseases. It has long been argued that SMC in atherosclerotic (AS) plaques is due to the migration and proliferation of SMC. Although a great deal of research has been done on the molecular mechanism of migration and proliferation of mesenchymal SMC, there is still no effective therapy to prevent occlusive vascular remodeling. However, in recent years, it has been reported that bone marrow cells are involved in the occurrence and development of vascular diseases. It is found that bone marrow cells may have the potential to differentiate into vascular progenitor cells which migrate to damaged blood vessels and differentiate into smooth muscle cells or endothelial cells which are involved in vascular repair remodeling and pathological changes. These findings provide a basis for exploring new therapies for vascular diseases. However, the molecular mechanism of smooth muscle differentiation of bone marrow cells remains unclear. However, it is exciting that in recent years, researchers have discovered a key smooth muscle differentiation factor-myocardinin. At present, the study of myocardin is still in its initial stage. Objective: to investigate the feasibility of platelet-derived growth factor B (PDGF-BB) and high concentration fetal bovine serum (20s) in inducing the differentiation of bone marrow mesenchymal stem cells (bone marrow mesenchymal stem cell,BMSC) into smooth muscle cells in vitro and the changes of myocardin expression during this process. Methods: bone marrow adherent isolation and digestion control were used to isolate mouse BMSC,. BMSC, was induced by PDGF-BB (50 渭 g / L) combined with high concentration fetal bovine serum (20s). The expression of 伪 -SMASM-MHCMHCmyocardin was detected by immunocytochemistry before induction and 4 days and 8 days after induction. At the same time, the morphological changes of cells were observed under inverted phase contrast microscope. Results: from the morphological point of view of single cell, BMSC appeared fusiform, branched or polygon before induction, and the volume of cells increased slightly after induction, but at 8 days after induction, there were bundles and swirls in the dense part of the cells. Similar to SMC. The expression of 伪 -SMASM-MHCMHCmyocardin protein increased and the average gray value decreased before induction and 4 days and 8 days after induction (P0.05). Conclusion: PDGF-BB combined with high concentration of fetal bovine serum (20s) can effectively induce the differentiation of BMSC into smooth muscle cells. Myocardin plays an important role in this process.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R329

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