血管收縮素II以及蛋白質激脢C在部分輸尿管阻塞時對於腎臟間質纖維化所扮演的角色

Role of Angiotensin II - Protein Kinase C Pathway for Renal Interstitial Fibrosis in Partial Ureteral Obstruction

阮雍順(Yung-Shun Juan)

指導教授 ： 黃俊雄

高雄醫學大學/醫學院/醫學研究所/碩士(2005年)

摘要

輸尿管部分阻塞會活化腎素-血管收縮素系統，並可以加強調節轉化生長因子β，腫瘤壞死因子α等進而造成細胞外間質蛋白的堆積。蛋白激脢C是一種絲胺酸-酥胺酸激脢，在訊息傳遞及生化功能都扮演著重要角色，本實驗主要研究單側輸尿管部分阻塞時，血管收縮素II和蛋白激脢C之間的關聯性。除此之外，我們利用蛋白激脢C抑制劑以及血管收縮素轉化脢抑制劑，研究蛋白激脢C以及血管收縮素II在腎臟皮質間質是否和誘發轉化生長因子β，以及第四類膠原蛋白的生成有關。
成年雄性大白鼠依單側輸尿管部分阻塞分成三個小組,即沒有藥物治療组(O组,N=12 ),使用血管收縮素轉換酵素抑制劑(ACEI)组 (enalapril) (E组, N= 12)和蛋白質激脢C抑制劑(chelerythrine)组(C组, N=12)。實驗控制組則是動過偽手術的大白鼠(N=12)。在單側輸尿管部分阻塞手術7天後取下大白鼠的腎臟作研究。測量腎小管間質的相對體積(Vv) 並使用特殊抗體PCNA, TUNEL做細胞核染色,並以免疫組織染色方法染轉換生長因子β(TGFβ)以及第四型膠原蛋白作組織學的檢查。利用西方墨點法測量細胞質與細胞膜蛋白激脢Cα，β以及fibronectin的濃度。
在單側輸尿管部分阻塞但未使用藥物治療的大白鼠中和控制組比較，腎盂積水的嚴重程度有意義地增加,腎臟間質的相對體積(Vv)也明顯的增加; 腎臟間質中的膠原蛋白堆積和標有PCNA或者TUNEL的核與控制組比較也都有明顯的增加。利用enalapril 或者chelerythrine治療，則發現第四型膠原蛋白以及轉化生長因子β的表現明顯減少。血管收縮素轉化脢抑制劑以及蛋白激脢C抑制劑抑制也會減少細胞質的蛋白激脢Cα，β轉位細胞膜的量。
這個研究顯示了腎激素－血管收縮素系統在阻塞性腎病變的致病激轉中扮演一個主要的角色。這些資料並認為血管緊縮素II可能經由蛋白激脢C的活化而作用。

關鍵字

腎臟間質纖維化 ； 部分輸尿管阻塞 ； 血管收縮素II ； 蛋白質激脢C

並列摘要

Partial unilateral ureteral obstruction will activate renin-angiotensin system and up-regulates the expression of transforming growth factor-β (TGF-β), tumor necrosis factor (TNF-α), and lead to the accumulation of extracellular cell matrix (ECM) proteins. Protein kinase C (PKC) is a family of serine-threonine kinases that plays a central role in signal transduction and biochemical functions. The aim of this study was to investigate the relationship between angiotensin II generation and protein kinase C activity in partial unilateral obstructed ureter. Furthermore, we studied whether locally produced angiotensin II mediates in TGF-β, and type IV collagen production in renal cortical interstitium, by examining the effects of a protein kinase C inhibitor and angiotensin converting enzyme inhibitor.
Adult male Sprague-Dawley rats were subjected to partial unilateral ureteral obstruction (PUUO) and divided into 3 groups, that is, those without treatment (group O , N=12), treated with angiotensin converting enzyme inhibitor (ACEI) (enalapril) (group E, N= 12) and those with protein kinase C inhibitor (chelerythrine) (group C, N=12). Control animals were sham operated (N=12). Rats were sacrificed at day 7. The relative volume of the tubulointerstitium (Vv) was measured. Proliferating cell nuclear antigen (PCNA), terminal deoxy transferase uridine triphosphate nick end-labeling (TUNEL), and TGF-β, and collagen IV were examined histologically using specific antibodies. Western blot technique was employed for detection of fibronectin and cytosolic or membranous PKCα and PKCβ.
In untreated rats with partial ureteral obstruction, the degree of hydronephrosis was significantly increased than control group, Vv was remarkably expended; collagen IV depositinion in the interstitium and PCNA labeling or TUNEL labeling nuclei were also increased. Increased accumulation of collagen IV and TGF-β expression was blunted by administration of enalapril or chelerythrine. Cytosolic PKCα and PKCβ translocation to membrane were significant and attenuated by ACEI and PKC inhibitor.
This study demonstrated that the renin-angiotensin system has a major role in the pathogenesis of the tubulointerstitial fibrosis of obstructive nephropathy and these data suggested that angiotensin II may active via the PKCα, β pathway.

並列關鍵字

Partial Ureteral Obstruction ； Renal Interstitial Fibrosis ； Protein Kinase C ； Angiotensin II

參考文獻

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