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  

The Role of DNA Double-strain Damage Repairing Mechanisms in Diabetic Atheroscolersis

作　　者：曾理[1,2] 丁群芳[1] 许婷媛[3] 罗方[1] 葛宁[1] 李诗彤 

机构地区：[1]四川大学华西医院老年科,成都610041 [2]四川省医学科学院.四川省人民医院干部科,成都610072 [3]成都军区总医院老年科,成都610083 [4]南充市中心医院老年科,南充637000

出　　处：《四川大学学报（医学版）》2017年第2期191-196,共6页Journal of Sichuan University(Medical Sciences)

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(P<0.05)。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(P<0.05)。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(P<0.05);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�Objective To identify the role of DNA double-strain damage repairing pathway in the development of diabetics atherosclerosis. Methods Wistar male rats were randomly divided into three groups： control group （group A）, balloon injury group （group B） and diabetes ＋ balloon injury group （group C）. Streptozotocin （STZ） was injected into rat abdomen to induce diabetes. After stabilizing high glucose, rats in group B and group C were both under aortic balloon injury technique and fed high lipid forage post-operatively. Glucose levels and weight were observed weekly. Segments of aortoa of three groups were taken at 2, 4, 6 and 8 weeks, staining of senescent β-galactosidase （SA-β-gal） staining, HE and changes of aorta under light microscope were observed. The area of tunica intima （I） and tunica media （M） in aorta was measured，and their ratio （I/M） were analyzed. Expressions of gamma-histong family 2A variant （γ-H2AX）, phosphorylated ataxia telangiectasia mutated （ATM）, phosphorylated checkpoint kinasen 2 （CHK2） and phosphorylated P53 were detected by immunohistochemical staining. Results SA-β-gal staining positive areas were dotted around in group B and group C [CM（155.3mm]but not in group A at two weeks.At the same time,a slight hyperlasia of aortic neointima was observed in HE staining of group B and group C. SA-β-gal staining was positive scattered within the tunica intima of aorta of group B and group C at four weeks, and HE staining promted a significantly greater of aortic neointima in the group C than that in the other two group （P 〈0.05）. Positive regions of SA-β-gal staining were more in group C than group B at six weeks. Typical atherosclerotic plaques were formed, vascular smooth muscle cells were disordered arranged and foam cells were aggregated in the plaques of group C at six weeks post-operatively, and intimal membrane areas increased than group A and group B （P 〈0.05）. At 8 weeks, SA-β-gal positive areas in group C were greater than i

关 键 词：DNA双链损伤修复机制 细胞衰老 糖尿病 动脉粥样硬化 

分 类 号：R587.2[医药卫生—内分泌] R543.5[医药卫生—内科学]