球形脂联素对2型糖尿病大鼠动脉粥样硬化的影响及其机制探讨

发布时间：2018-03-28 14:40

本文选题：球形脂联素　切入点：2型糖尿病　出处：《山西医科大学》2017年硕士论文

【摘要】：目的:建立2型糖尿病(T2DM)大鼠模型,观察不同时间段(4、8、12周)胸主动脉组织中转化生子因子β1(TGF-β1)、Smad3、Smad7、1型胶原蛋白(Col-1)的表达情况;同时比较球形脂联素(gAd)干预后4、8、12周大鼠胸主动脉组织中TGF-β1、Smad3、Smad7、Col-1与T2DM大鼠模型组的变化,探讨gAd与TGF-β1/Smads信号通路之间的关系及其对T2DM大鼠动脉粥样硬化(AS)保护作用的机制,为临床拓展防治T2DM大血管并发症提供新思路。方法:90只雄性sprague-dawley(SD)大鼠随机分为正常对照组(N组,n=24)和T2DM造模组(n=66),成模的53只再分为T2DM组(D组,n=26)、干预组(A组,n=27)。A组给予gAd 10μg·kg~(-1)·d~_(-1)腹腔推注,余两组给予等量生理盐水。各组分别于4、8、12周末随机取8只大鼠麻醉后采血,测空腹血糖(FPG)、总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C);留取胸主动脉标本,行HE染色后光镜观察其形态学改变,并用免疫组化法测Col-1的表达,应用蛋白免疫印迹(Western blotting)、实时荧光定量聚合酶链反应(RT-PCR)法测TGF-β1、Smad3、Smad7蛋白及其mRNA的表达。据实验结果及统计学处理分析,探讨它们之间的关系。结果:1.各时间段中,D组大鼠FPG、TC、TG、LDL-C明显高于N组,而HDL-C降低;A组FPG、TC、TG、LDL-C均低于相应D组,而HDL-C较之升高(P均0.05)。2.HE染色显示:N组大鼠动脉壁内、中、外膜三层结构完整,管壁光滑,内膜及中层细胞排列规则。D组可见动脉壁内、中、外膜界限不清、轻度紊乱,内膜完整性破坏,内皮细胞部分脱落,中膜平滑肌细胞形态多样,数量增多,排列不规则;并且随着T2DM病程延长,上述病变呈时间依赖性加重。g Ad干预后,A组上述病变较相应D组分别减轻,且随着干预时间延长,胸主动脉AS程度呈时间依赖性减轻。3.免疫组化、Western blotting和RT-PCR法显示:D组TGF-β1、Smad3、Col-1的表达明显多于N组,而Smad7表达减少(P均0.05);A组TGF-β1、Smad3、Col-1表达明显低于同期D组,而Smad7表达增多。且随着gAd干预时间延长,TGF-β1、Smad3、Col-1的表达逐渐减少,Smad7表达逐渐增多(P0.05)。结论:1.T2DM模型组大鼠胸主动脉TGF-β1、Smad3、Col-1表达水平明显升高,而Smad7表达下降,并且随着病程的延长,TGF-β1、Smad3、Col-1水平依次升高,Smad7依次降低,与光镜下胸主动脉AS程度一致,提示TGF-β1/Smads信号通路的异常表达可能参与了T2DM大鼠AS的发生、发展。2.gAd干预组大鼠胸主动脉TGF-β1、Smad3、Col-1表达水平明显下降,而Smad7表达升高,并且随着干预时间延长,TGF-β1、Smad3、Col-1水平依次下降,Smad7依次升高。光镜下示胸主动脉AS程度逐渐减轻,提示gAd通过上调Smad7或下调TGF-β1、Smad3来干扰TGF-β1/Smads传导通路,进一步抑制Col-1等致纤维化因子的生成及沉积,发挥抗血管壁纤维化作用,从而缓解T2DM大鼠AS进程。
[Abstract]:Objective: to establish a rat model of type 2 diabetes mellitus (T2DM) and to observe the expression of transforming progenitor factor 尾 1 (TGF- 尾 1) in thoracic aorta at 12 weeks. At the same time, the changes of TGF- 尾 1, Smad3, Smad7 and Col-1 in thoracic aorta of rats treated with globular adiponectin (Aden) for 12 weeks were compared with those of T2DM rats, and the relationship between TGF- 尾 1/Smads signaling pathway and gAd and the protective mechanism of TGF- 尾 1/Smads on atherosclerosis in T2DM rats were investigated. Methods 90 male Sprague-dawley SD rats were randomly divided into normal control group (n = 24) and T2DM model group (n = 53). 53 rats were divided into T2DM group D group (n = 26) and intervention group A group (n = 10 渭 g 路kg ~ (-1)) d ~ (-1) 路d ~ (-1). The other two groups were given the same amount of normal saline. At the end of 12 weeks, 8 rats in each group were randomly selected for blood collection after anaesthesia. Fasting blood glucose (FPG), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) were measured, and the morphological changes of thoracic aorta were observed by light microscope after HE staining, and the expression of Col-1 was detected by immunohistochemical method. The expression of TGF- 尾 1 Smad3 Smad7 protein and its mRNA were detected by Western blotting and real-time fluorescence quantitative polymerase chain reaction (RT-PCR). Results 1. The LDL-C of group D was significantly higher than that of group N, while the LDL-C of group A was lower than that of group D, while the level of HDL-C in group A was lower than that of group D, and HDL-C was significantly higher than that of group N by 0.05).2.HE staining. The three layers of the adventitia were complete, the wall of the tube was smooth, and the inner wall of artery was found in group D with regular arrangement of intimal and medial cells. The boundary of the middle and outer membrane was not clear, there was slight disorder, the integrity of the intima was destroyed, the endothelial cells were partially shed, and the morphology of smooth muscle cells of the media was various. With the prolongation of the course of T2DM, the above pathological changes were aggravated in a time dependent manner. After the intervention of Ad, the above lesions in group A were alleviated respectively than those in group D, and with the prolongation of the duration of intervention. The expression of TGF- 尾 1, Smad3 and Col-1 in group D was significantly higher than that in group N, while the expression of Smad7 in group A was significantly lower than that in group D, and the expression of TGF- 尾 1 and Smad3 Col-1 in group A was significantly lower than that in group D at the same time. However, the expression of Smad7 was increased, and the expression of TGF- 尾 1, Smad3, Col-1 was gradually decreased with the prolongation of gAd intervention. Conclusion the expression of TGF- 尾 1, Smad3 and Col-1 in thoracic aorta of T2DM group was significantly increased, while the expression of Smad7 was decreased in the TGF- 尾 1 Smad3 Col-1 of thoracic aorta of rats treated with T2DM. With the prolongation of the course of disease, the level of TGF- 尾 1, Smad3 and Col-1 increased and decreased in turn, which was consistent with the degree of thoracic aortic atherosclerosis under light microscope, suggesting that the abnormal expression of TGF- 尾 1/Smads signal pathway may be involved in the pathogenesis of as in T2DM rats. 2. The expression of TGF- 尾 1 and Smad3 Col-1 in thoracic aorta of rats treated with Ad significantly decreased, while the expression of Smad7 increased, and the level of Smad3 Col-1 decreased in turn with the prolongation of intervention time. The degree of as in thoracic aorta decreased gradually under light microscope. It is suggested that gAd may interfere with the TGF- 尾 1/Smads pathway by up-regulating Smad7 or down-regulating TGF- 尾 _ 1 / Smad3, further inhibit the formation and deposition of fibrogenic factors such as Col-1, and play an anti-vascular fibrosis role, thereby alleviating the process of as in T2DM rats.
【学位授予单位】：山西医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R587.2

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