DNA双链损伤修复机制在糖尿病致动脉粥样硬化中的作用研究

发布时间：2018-06-21 00:21

本文选题：DNA双链损伤修复机制 + 细胞衰老　；参考：《四川大学学报(医学版)》2017年02期

【摘要】：目的探讨DNA双链损伤修复机制在糖尿病致动脉粥样硬化中的作用。方法将Wistar雄性大鼠随机分为3组,即正常对照组(A组),主动脉内膜球囊损伤组(B组),糖尿病模型+主动脉内膜球囊损伤组(C组)。C组采用链脲霉素(STZ)一次性腹腔注射建立糖尿病模型,注射STZ 72h后,B组与C组大鼠均被施行主动脉球囊损伤术,术后分别予以高脂饲料饲养;A组予以基础饲养,每周监测血糖水平及体质量变化。分别于术后2周、4周、6周、8周,取大鼠主动脉进行老化β-半乳糖苷酶(SA-β-gal)染色、HE染色,并计算主动脉内膜面积、中膜面积、内中膜面积比,免疫组织化学染色检测磷酸化共济失调毛细血管扩张突变基因(ATM)、磷酸化细胞周期检测点激酶2(CHK2)、磷酸化P53、磷酸化组蛋白2A变异体(γ-H2AX)的表达。结果术后2周,A组大鼠主动脉内膜老化SA-β-gal染色呈阴性,B组和C组大鼠老化SA-β-gal染色阳性区域较少且散在分布;HE染色示B组和C组大鼠主动脉内膜开始出现少量增生。术后4周,B组和C组大鼠主动脉内膜老化SA-β-gal染色呈阳性;HE染色示C组大鼠主动脉内膜增厚明显,主动脉内膜面积较A组和B组增加(P0.05)。术后6周,C组大鼠主动脉内膜老化SA-β-gal染色呈阳性且面积较B组增加;HE染色示C组大鼠主动脉壁形成典型动脉粥样硬化斑块,斑块内平滑肌细胞排列紊乱,泡沫细胞聚集,管腔狭窄,与A组、B组相比,主动脉内中膜面积比增加(P0.05)。术后8周,C组大鼠主动脉内膜老化染色阳性面积较B组增加;HE染色示C组大鼠主动脉腔明显狭窄,增生部分突入管腔,内膜面积、内中膜面积比较A组和B组增加(P0.05);免疫组化染色示C组大鼠主动脉内膜中γ-H2AX、磷酸化ATM、磷酸化CHK2、磷酸化P53表达均呈阳性,上述蛋白在B组大鼠主动脉内膜中表达均呈弱阳性。结论糖尿病状态下,血管内皮细胞衰老激活,DNA双链损伤加剧,双链损伤修复机制参与了糖尿病致动脉粥样硬化的发生发展。
[Abstract]:Objective to investigate the role of DNA double strand damage repair mechanism in atherosclerosis induced by diabetes mellitus. Methods Wistar male rats were randomly divided into three groups. The diabetic model was established by intraperitoneal injection of streptozotocin (STZ) by intraperitoneal injection of streptozotocin (STZ) in normal control group, aortic intima balloon injury group (group B) and diabetic model aortic intima balloon injury group (group C). 72 hours after STZ injection, the rats in group B and group C were treated with balloon injury of aorta. The rats in group A were fed with high fat diet respectively. The blood glucose level and body mass were monitored weekly. The aorta of the rat was harvested for aging 尾 -galactosidase SA- 尾 -gal) staining at 2 weeks, 4 weeks, 6 weeks and 8 weeks, respectively. The area of intima, the area of middle membrane and the ratio of area of medial membrane of aorta were calculated. Immunohistochemical staining was used to detect the expression of phosphorylated ataxia telangiectasia mutant gene, phosphorylated cell cycle detection point kinase 2, phosphorylated p53, and phosphorylated histone 2A variant (纬 -H2AX). Results two weeks after operation, SA- 尾 -gal staining was negative in group A and group C, and there were few SA- 尾 -gal staining positive areas in group B and C, and scattered HE staining showed that a small number of hyperplasia of aortic intima began to appear in group B and group C. 4 weeks after operation, SA- 尾 -gal staining showed that the aortic intima of group C was thicker than that of group A and group C, and the area of aortic intima was increased by P0.05a than that of group A and B by SA- 尾 -gal staining. At 6 weeks after operation, SA- 尾 -gal staining of aortic intima aging in group C was positive and its area was larger than that in group B. He staining showed that typical atherosclerotic plaques were formed in aortic wall of rats in group C, smooth muscle cells in plaques were disordered and foam cells were accumulated. Compared with group A and B, the ratio of medial area of aorta to lumen stenosis was increased (P 0.05). At 8 weeks after operation, the positive area of aging staining of aortic intima in group C was increased compared with that in group B. The results of HE staining showed that the aortic lumen in group C was obviously narrow, and the proliferative part protruded into the lumen of aorta, and the area of intima was increased. Immunohistochemical staining showed that the expression of 纬 -H2AX, phosphorylated ATM, phosphorylated CHK2 and phosphorylated p53 in aortic intima of group C were all positive, and the expression of these proteins was weakly positive in the intima of aorta of group B. Conclusion under the condition of diabetes, the aging activated DNA double strand damage of vascular endothelial cells is aggravated, and the repair mechanism of double strand damage is involved in the occurrence and development of diabetes induced atherosclerosis.
【作者单位】：四川大学华西医院老年科;四川省医学科学院·四川省人民医院干部科;成都军区总医院老年科;南充市中心医院老年科;
【分类号】：R587.2;R543.5

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