阿托伐他汀降低2型糖尿病大鼠主动脉磷酸化p38丝裂素活化蛋白激酶蛋白的表达

Atorvastatin ameliorate the expression of phosphorylated p38 mitogen-activated protein kinase in type 2 diabetic rats aorta

目的 探讨p38丝裂素活化蛋白激酶（p38MAPK）与糖尿病大血管病变的关系及阿托伐他汀的干预作用. 方法 选用25只4周龄雄性Wistar大鼠,数字表法随机分为正常对照组（NC组,n=6）和实验组（EX组,n=19）,EX组采用高脂高糖饲料喂养联合链脲佐菌素注射建立具有2型糖尿病动脉粥样硬化特点的动物模型.将成模糖尿病大鼠（n=15）随机分为2型糖尿病空白对照组（DM组,n=7）及阿托伐他汀干预组（ATR组,n=8）.ATR组给予阿托伐他汀10 mg·kg^-1·d^-1灌胃8周,DM组及NC组给予等量的饮用水灌胃.测定大鼠血清、细胞间黏附分子1（ICAM-1）、血管细胞黏附分子1（VCAM-1）、血脂水平,免疫组织化学法检测大鼠胸主动脉磷酸化p38MAPK（p-p38MAPK）、核因子（NF）-κB、单核细胞趋化蛋白1（MCP-1）蛋白表达水平.数据采用SNK-q检验、Pearson相关分析进行比较分析.结果 HE染色后可见DM组大鼠主动脉管壁结构层次不清,内膜增厚,内皮细胞肿大变性,中膜平滑肌细胞排列紊乱,胶原纤维增生.与NC组相比,DM组大鼠主动脉p-p38MAPK、NF-κB、MCP-1蛋白表达水平明显升高（Z=-3.466、-3.728、-3.832;均P＜0.05）.ATR组大鼠主动脉中p-p38MAPK、NF-κB、MCP-1蛋白表达水平较DM组明显降低（Z=-2.308、-2.160、-2.501,均P＜0.05）.相关分析显示主动脉NF-κB、MCP-1蛋白表达和p-p38MAPK蛋白表达呈显著正相关（r=0.406、0.310,均P＜0.05）.与NC组相比,DM组大鼠血清NF-κB、ICAM-1、VCAM-1、总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL）水平明显升高（t=-9.200、-5.586、-7.041、-8.788、-5.247、-5.142,均P＜0.05）,HDL水平降低（t＝5.598,P＜0.05）.治疗8周后,ATR组大鼠血清中NF-κB、ICAM-1、VCAM-1、TG、TC、LDL水平均较DM组明显降低（t=3.661、3.360、2.496、4.348、3.077、3.446,均P＜0.05）,HDL水平较DM组有所升高,但组间差异无统计学意义（t=-1.983,P＞0.05）. 结论 p38 MAPK通路的激活在糖尿病大血管病变发生发展中起重要作用,阿托伐他汀可通过降低p38MAPK磷酸化水平,抑制炎症反应,起到大血管保护作用.

Objective To explore the relationship between phosphorylated p38 mitogen-activated protein kinase （p-p38 MAPK） and diabetic macroangiopathy,and the intervention effect of atorvastatin.Methods Total of 25 healthy male Wistar rats （4 weeks old） were randomly divided into experiment group （EX,n=19） and normal control group （NC,n=6） with random number table,the rats were fed with standard rodent chow diet or high-fat,high-sugar diet in the control and EX group.The rates in EX group were injected intraperitoneally with 1% streptozotocin（STZ）（30 mg/kg） and blood glucose≥7.8 mmol/L was considered as DM.The well-estabolished DM rats model were then randomly divided into two subgroups：diabetic control group （DM group,n=7） and atorvastatin-treated diabetic group （ATR group,n=8）.The rats in ATR group were given intragastric administration of atorvastatin （10 mg· kg-1· d-1） for 8 weeks,and DM group was given drinking water in the same way.Body weight was measured weekly.The expression of phosphorylated p38 MAPK,neuclear factor（NF）-κB,and monocyte chemoattractant protein-1 （MCP-1） in the thoracic aorta and blood lipids,intercellular cell adhesion molecule-1（ICAM-1）,vascular cell adhesion molecule-1（VCAM-1） were measure by immunohistochemistry.The data were analyzed with SNK-q and Pearson correlation analysis.Results Structural destructions in DM rat aorta tissue were observed by HE staining,which characterized by endothelia cells swollen and degeneration and intima thickness.Smooth muscle disorders and collagen fiber hyperplasia in tunica media were also found in DM rats when compared to NC animals.All these pathological alterations can be improved by atorvastatin treatment.The expression of p-p38MAPK,NF-κB and MCP-1 was significantly increased in DM rats when compared to those in NC group （Z=-3.466,-3.728,-3.832,P〈0.05） and all these increasing were partly reversed by atorvastatin treatment（Z=-2.308,-2.160,-2.501,P〈 0.05）.The expression of NF-κB and MCP-1 were both found to be correlated with p-p38 MAPK levels（r=0.406,0.310,both P〈0.05）.Compared with NC group,the levels of serum NF-κB,ICAM-1,VCAM-1,total cholesterol（TC）,triglyceride（TG）,and low-density lipoprotein（LDL） were significantly increased in DM group（t=-9.200,-5.586,-7.041,-8.788,-5.247,-5.142,all P〈 0.05）,whereas the level of high-density lipoprotein（HDL） decreased in DM group （t=5.598,P〈0.05）.After 8 weeks of atorvastatin treatment,the serum levels of NF-κB,ICAM-1,VCAM-1,TG,TC,LDL were all significantly decreased compared to DM group（t=3.661,3.360,2.496,4.348,3.077,3.446,all P〈0.05）.Conclusions Activation of p38 MAPK pathway plays an important role in the development of diabetic macroangiopathy.Atorvastatin may ameliorate diabetic macrovascular disease through activating p38 MAPK and decreasing vascular inflammation response.