摘要
目的探讨蛋白激酶 C(PKC)-βⅠ,βⅡ在糖尿病肾病(DN)小鼠肾脏中各部位的分布、表达以及血管紧张素受体拮抗剂替米沙坦对其影响。方法 18只小鼠随机分为正常组、DN 组和治疗组(TG 组)。采用半定量免疫荧光技术检测肾小球内 PKC-βⅠ、βⅡ,转化生长因子(TGF-β1)和血管内皮细胞生长因子(VEGF)的表达情况,激光共聚焦及免疫印迹技术检测 PKC-βⅠ,βⅡ在肾组织中的分布与表达。结果与正常组相比,DN 小鼠近曲小管上皮细胞腔膜侧 PKC-βⅠ,-βⅡ的表达较强,而皮质和内髓集合管上皮细胞 PKC-βⅡ的表达消失;DN 小鼠肾皮质和外髓 PKC-β1的表达量较多(P<0.01),而肾皮质内 PKC-βⅡ的表达则明显较低(P<0.01)。半定量免疫荧光进一步表明,PKC-βⅠ、TGF-β1和 VEGF 在 DN 小鼠肾小球内的表达量明显高于正常组(分别上调0.48、0.20和0.24倍,均 P<0.01),而 PKC-βⅡ的表达则下调0.27倍(P<0.05),其中 PKC-β1的表达与 TGF-β1呈正相关(r=0.649,P=0.030)而与 VEGF 无关(r=0.387,P=0.079),PKC-βⅡ的表达与 TGF-β1、VEGF 均无关。替米沙坦能部分纠正上述变化。结论 (1)DN 小鼠肾组织中 PKC-βⅠ、βⅡ的表达和分布发生变化,提示它们参与 DN 近曲小管功能改变,其中 PKC-β1可能通过影响肾小球 TGF-β1的表达参与 DN 肾小球的肥大。(2)DN 时肾素血管紧张素系统的活性增加可能是 PKC-βⅠ,βⅡ异常激活的重要原因,替米沙坦可能通过部分改善 PKC-βⅠ,βⅡ的表达来实现其肾脏保护作用。
Objective To investigate the localization and expression of protein kinase C （PKC）-βⅠ,βⅡ in diabetic nephropathy （DN） mouse kidney and its relation to angiotensin receptor blocker telmistartan （Micardis）. Methods Eighteen mice were divided into three groups： normal group, DN group and Micardis-treated group （ n = 6, each group ）. The expression of PKC-βⅠ、βⅡ, transforming growth factor- beta 1 （ TGF-β1 ） and vascular endothelial growth factor （VEGF） in glomeruli was measured by semiquantitative immunofluorescence histochemistry, the localization of PKC-βⅠ,βⅡ was detected by confocal immunofluorescence laser scanning microscopy and the expression of PKC-βⅠ,βⅡ in renal cortex, outer and inner medulla were evaluated by semiquantitative Western blotting. Results Compared to normal mice, the expression of PKC-βⅠ and βⅡ on apical membrane of proximal tubule epithelial cells of DN mice was significantly increased, whereas the expression of PKC-βⅡ on cortical and inner medullary collecting duct was decreased. Western blotting detected increasing expression of PKC-βⅠ in the renal cortex and outer medulla （ P 〈 0. 01 ）, and decreasing expression of PKC-βⅡ in renal cortex of DN mice （ P 〈 0. 01 ）. Enhanced expression of PKC-βⅠ as well as TGF-β1 and VEGF （ P 〈 0. 01 ） were shown in the glomenlli of DN mice, where the expression of PKC-βⅡ was decreased （P 〈0. 05）. Meanwhile, PKC-βⅠ exhibited a positive correlation to TGF-β1 （ r = 0. 649, P = 0. 030 ）, but no correlation to VEGF （ r = 0. 387, P = 0. 079）. Micardis could partly attenuate above changes. Conclusion The localization and expression of PKC-βⅠ,βⅡ are altered in DN mice, PKC-βⅠ,βⅡ may change the function of proximal tubule and PKC-βⅠ may contribute to glomerular hypertrophy through influencing the expression of glomerular TGF-β1. Treatment with Micardis can partly improve the abnormal expression and distribution of PKC-βⅠ,βⅡ in kidneys of DN mice, which suggests that renin-angiotensin-system is implicated in the pathogenesis of DN by regulating the expression and activation of PKC-βⅠ,βⅡ isoforms.
出处
《中华医学杂志》
CAS
CSCD
北大核心
2007年第28期1991-1995,共5页
National Medical Journal of China
