摘要
目的:探讨c-jun N端蛋白激酶1(JNK1)信号分子在糖尿病(DM)大鼠心肌细胞肥大和纤维化过程中的作用。方法:使用60mg/kg链脲佐菌造模后,将造模成功的48只大鼠分为3组,依次为糖尿病模型组(A组,n=16),腹腔注射生理盐水20μg/(kg·d);AngⅡ给药组(B组,n=16),将血管紧张素Ⅱ+0.9%生理盐水的ALZET微渗透泵植入皮下,以剂量700 ng/kg·d血管紧张素Ⅱ连续给药6周;SP600125给药组(C组,n=16),一次性尾静脉注射15 mg/kg SP600125。另外,选取20只大鼠为正常对照组(D组),给予等量溶媒。连续喂养两个月后检测相关指标。每周检测大鼠的空腹血糖水平,并称重,之后处死大鼠,称量心脏重量,计算心体比值和左室指数,同时应用免疫组化法检测心肌组织中Vimentin、collagenⅠ和α-actin的表达情况,另外,应用RT-PCR检测心肌组织中PI3Km RNA和Akt-1m RNA的表达情况。结果:D组大鼠状态良好,无死亡现象;A组和B组大鼠状态不佳,C组大鼠状态较好,三组大鼠均有死亡现象;A组、B组和C组大鼠的体重、心重明显低于D组,而心体比值显著高于D组,且差异具有统计学意义(P<0.05);A、B、C三组大鼠的体重、心重和心体比值之间的差异具有统计学意义(P<0.05);A、B、C组大鼠造模后空腹血糖水平明显高于D组,差异具有统计学意义(P<0.05);与D组相比,A组、B组和C组大鼠心肌组织中Vimentin、collagenⅠ和α-actin的平均光密度值明显升高;C组大鼠心肌组织中Vimentin、collagenⅠ和α-actin的平均光密度值显著低于A组和B组,同时B组大鼠心肌组织中Vimentin、collagenⅠ和α-actin的平均光密度值明显高于A组,差异均具有统计学意义(P<0.05);A组、B组和C组大鼠心肌组织中PI3Km RNA和Akt-1m RNA表达水平明显高于D组,C组大鼠心肌组织中PI3Km RNA和Akt-1m RNA表达水平显著低于A组和B组,而A组大鼠心肌组织中PI3Km RNA和Akt-1m RNA表达水平明显低于B组,差异均具有统计学意义(P<0.05)。结论:JNK1信号分子可以通过IRS-1-PI3K-Akt途径影响信号传导,进而诱发糖尿病心肌病,Vimentin、collagenⅠ和α-actin表达水平升高,加速心肌细胞肥大和纤维化的进程。使用抑制剂后能明显改善这些蛋白的表达,这为临床上的治疗提供理论基础。
Objective： To investigate the role of c-junN end protein kinase 1 （JNK1） signaling molecules in the process of cardiomyocyte hypertrophy and fibrosis of diabetic rat. Methods： 60 mg/kg streptozocin was used in modeling, and 48 model rats were divided into 3 groups. The diabetic model group （group A, n=16） was given intraperitoneal injection of saline 20 μg/ （kg·d）. The Ang- II medication group （group B, n=16） was given Angiotensin- II plus 0.9% saline micro ALZET osmotic pump subcutaneous implant and angiotensin-II continuous dosing 6 weeks 700 ng/（kg·d）. The SP600125 medication group （group C, n=16） was given one-time tail intravenous injection 15 mg/kg of SP600125. In addition, 20 rats were treated as normal control group （group D）, which were given the amount of solvent. The related indicators were tested after two months of continuous feeding. The levels of fasting glucose and the weight of rats were tested weekly. After that, the rats were killed and the hearts＇ weight was tested, and the heart body ratio and left ventricular index were calculated. The expression of Vimentin, collagen I and α-actin in myocardial tissue were detected by immunohistochemical method at the same time. Meanwhile, the RT-PCR was applied to detect the expression of myocardial tissue PI3KmRNA and Akt- 1 mRNA. Results： Rats of group D were in good condition, no death occurred. Rats in group A and group B were in poor condition and rats of group C was in better condition; there were death phenomenon in the three groups of rats. The levels of body weight and heart weight of rats in group A, B and C were lower than those of group D, while the ratio of heart to body was significantly higher than that of group D, and the differences were statistically significant （P〈0.05）. There was statistical significance in the body weight, the heart weight and the ratio of heart to body among the rats in group A, B and C （P〈0.05）. The levels of fasting glucose of the rats in group A, B and C after modeling were significantly higher than those of before modeling and group D, and the differences were statistically significant （P〈0.05）. Compared with group D, the average optical density values of Vimentin, collagen I and α-actin in the myocardial tissue of group A, B and C obviously rised. The average optical density values of Vimentin, collagen I and α-actin in the myocardial tissue of group C were significantly lower than those of group A and B, and the average optical density values of Vimentin, collagen I and α-actin in the myocardial tissue of group B were higher than those in group A, and the differences were statistically significant （P〈0.05）. The expression levels of PI3KmRNA and Akt- 1mRNA in the myocardial tissue of rats of group A, B and C were obviously higher than those of group D, and the PI3KmRNA and Akt-1mRNA expression level of the myocardial tissue of rats in group C were significantly lower than those in group A and B.And the myocardial tissues PI3KmRNA and Akt-lmRNA expression levels in rats of group A were lower than those of group B, and the differences were statistically significant （P〈0.05）. Conclusion： JNK1 signaling molecules can influence signal transduction through the IRS-1-PI3K-Akt pathway, and then induce diabetes cardiomyopathy and the high expression levels of Vimentin, collagen I and α-actin, accelerate the process of myocyte hypertrophy and fibrosis. The expression of these proteins can be obviously improved after using inhibitor, which offers a theoretical basis for clinical treatment.
出处
《现代生物医学进展》
CAS
2017年第31期6018-6023,共6页
Progress in Modern Biomedicine
基金
2013年度全国临床医药研究专项基金项目(L2012057)
辽宁省第二批科学技术计划项目(2013225049)
