[目的]探讨普伐他汀和洛沙坦联合应用对慢性环孢素A(CsA)肾毒性模型大鼠抗纤维化作用的分子机制.[方法]取Sprague-Dawley雄性大鼠随机分为对照组(橄榄油1mg/kg)、CsA毒性组(皮下注射CsA 15mg/kg)、洛沙坦治疗组(洛沙坦10mg/kg+CsA)、普伐他汀治疗组(普伐他汀20mg/kg+CsA)、联合治疗组(CsA+洛沙坦+普伐他汀),均每日给药1次,持续4周.检测各组大鼠肾功能、收缩期血压、血脂水平;利用三色染色观察肾组织纤维化程度;利用Northern杂交、RNA原位杂交、免疫印迹法分别检测转化生长因子β1(TGF-β1)和TGF-β诱导基因h3(βig-h3)的表达.[结果]与CsA毒性组比较,普伐他汀和洛沙坦单独治疗组肾小管间质纤维化明显减轻(洛沙坦24.1%±4.0%,普伐他汀30.3%±5.2%,P〈0.01,2.0%±3.0%),同时TGF-β1(洛沙坦230%±20%,普伐他汀240%±15%,P〈0.01)和βig-h3(洛沙坦178%±21%,普伐他汀167%±10%,P〈0.01)表达均明显降低,联合治疗进一步降低上述指标水平(肾小管间质纤维化程度13.5%±2.5%,TGF-β1 150%±28%,βig-h3 126%±9%,P〈0.01).直线相关分析结果显示,βig-h3表达与TGF-β1(r=0.787,P〈0.001)和肾小管间质纤维化程度(r=0.688,P〈0.001)呈正相关.但是各组收缩期血压和血脂水平间差异均无统计学意义(P〉0.05).[结论]在慢性CsA肾毒性中,普伐他汀和洛沙坦联合应用通过抑制βig-h3表达起到抗纤维化协同作用,而不依赖于降低血压或降低血脂作用.
OBJECTIVE To explore the anti-fibrosis mechanism of combined application of pravastatin and losartan in rats model of chroniccyclosporine A(CsA) nephrotoxicity. METHODS Male Sprague Dawley rats were randomly divided into control group(olive oil 1 mg/kg), CsA group(CsA 15 mg/kg), losartan group (CsA 15 mg/kg and losartan 10 mg/kg), pravastatin group(CsA 15 mg/kg and pravastatin 20 mg/kg) and combined application group(CsA 15 mg/kg, losartan 10 mg/kg and pravastatin 20 mg/kg), and they were administrated of drugs by 1 time per day for 4 weeks. Renal function,systolicblood pressure and blood lipid level were measured.Masson trichrome staining was used to observed the tubular interstitial fibrosis (TIF), and the expressions of transforming growth factor β1 (TGF-β1) and TGF-β inducible gene-h3 (βig-h3) were detected by Northern blot, in situ hybridization and western blotting. RESULTS Compared with the CsA group, the pravastatin and losartan group showed a significant decrease of TIF (losartan.24. 1% ± 4.0 % ; pravastatin.30.3 % ± 5.2 %, P〈 0.01 vs. 42.0% ± 3.0%) and had a statistically significant decrease in the expression of TGF-β1 (losartan. 230% ± 20% ; pravastatin. 240% ± 15%, P 〈 0.01) and βig-h3 (losartan. 178% ± 21% pravastatin: 167% ± 10%, P 〈 0.01). Combined application group showed a further decrease of these parameters compared with other groups (TIF.13.5 % P%0. 01). Linear correlation analysis revealed that ± 2.5% ;TGF-β1:150% ± 28% ;βig-h3.126% ± 9%, βig-h3 expression positively associated with TGF-~I expression (r = 0. 787, P〈0. 001) and TIF (r = 0. 688, P〈0. 001). There were no significant differences in systolic blood pressure and serum lipid level between each group. CONCLUSION Combined application of pravastatin and losartan played a synergistic effect on anti-fibrosis by inhibiting βig-h3 expression in a model of chronic CsA nephrotoxicity, and this effect was independent of their lowing blood pressure a