动脉粥样硬化家兔蛋白质硝基化修饰及补肾抗衰片干预研究

Effect of Bushen Kangshuai Tablet on Protein Nitrative Modification in Atherosclerotic Rabbits

摘要:

目的：研究补肾抗衰片对家兔动脉粥样硬化（AS）病变后血管组织蛋白质硝基化修饰的影响。方法：56只日本大耳白兔随机分为正常组（NOR）、模型组（CHOL）、补肾抗衰片组（BSKS，1 g·kg^-1·d^-1）、辛伐他汀组（SIMVA，5 mg·kg^-1·d^-1）；各组分别于给药前、给药后8，12，16周采血，最后1次采血后处死动物，无菌条件下取主动脉，检测血清环氧合酶-2（COX-2） 活性以及一氧化氮（NO）、3-硝基酪氨酸（3-NT）水平，检测主动脉诱导型一氧化氮合酶（iNOS）mRNA、p38 MAPK mRNA的表达，p38 MAPK阳性面积以及eNOS蛋白水平。结果：与正常组比较，动脉粥样硬化造模的不同时期都可检测到 iNOS表达和蛋白质酪氨酸的硝基化，模型组内膜明显增厚、纤维帽较薄，斑块内有大量脂质沉积，血清3-NT水平明显升高，补肾抗衰片干预后，血清3-NT水平下降，NO水平明显升高，而COX-2活性没有明显变化；免疫组化染色发现，主动脉p38 MAPK mRNA，iNOS mRNA基因在正常组仅有少量表达，AS病变组p38 MAPK mRNA，iNOS mRNA表达增加；与模型组比较，补肾抗衰片也明显降低了家兔p38 MAPK水平；p38 MAPK mRNA，iNOS mRNA基因表达明显下降，辛伐他汀也有类似的抑制硝基化效应。结论：动脉粥样硬化时，组织蛋白质酪氨酸发生硝基化损伤，中药复方制剂补肾抗衰片在AS病变中具有重要的抗硝基化作用，其保护机制可能是通过调控p38 MAPK mRNA，iNOS mRNA基因的表达以及影响iNOS/NO-COX-2通路中相关酶的活性，同时补肾抗衰片可能通过对抗硝基化反应稳定动脉粥样硬化斑块。

Abstract:

Objective: This study was to determine the effect of the Bushen Kangshuai tablet on nitric xidesynthase (NOS) /nitric oxide (NO) -cyclooxygenase-2 (COX-2) pathway and its associated protein nitrative modification influence in atherosclerotic rabbits. Method: Fifty-six rabbits were randomly divided into normal group, model group, Bushen Kangshuai tablet therapeutic group (1 g·kg^-1·d^-1) and simvastatin therapeutic group (5 mg·kg^-1·d^-1). The blood sample of all animals were collected before administration, after supplementing with the 8 weeks, 12 weeks and 16 weeks, the animals were sacrificed under aseptic conditions. Aortic iNOS mRNA, p38-mitogen activated protein kinase (p38 MAPK) mRNA expression was measured by Q-PCR method, the serum COX-2 activity and NO, 3-nitrotyrosine (3-NT) levels were measured by ELISA, and eNOS protein level was detected by western blot analysis. Result: iNOS expression and protein tyrosine nitration could be detected in different periods of atherosclerosis, model group showed intimal thickening, thin fibrous cap, a large lipid plaque deposition. Significant ieduction of serum 3-NT levels was found when atherosclerosis occured, but Bushen Kangshuai tablets could decreased the expression of serum 3-NT levels, NO levels were significantly increased, while COX-2 activity did not change significantly. Bushen Kangshuai tablets significantly reduced the rabbit p38 MAPK levels. The model group showed a significant increase in iNOS and p38 MAPK gene expression. The simvastatin had a similar inhibitory effect of nitration. Conclusion: Bushen Kangshuai tablets in atherosclerotic lesions plays an important role in anti-nitration, the protective mechanism may regulate p38 MAPK mRNA, iNOS mRNA gene expression and iNOS/NO-COX-2 pathway related enzymes possibly through anti-nitration reaction to stabilize of the atherosclerotic plaques.