β抑制蛋白2及微管相关蛋白轻链3在大鼠肾脏缺血再灌注损伤中的改变及意义

The changes of β-arrestin2 and microtubule-associated protein light chain 3 in renal tissue of rats with renal ischemia reperfusion injury

目的探讨β抑制蛋白2（β—arrestin2）及微管相关蛋白轻链3（microtubule—associated protein light chain 3，LC3）在急性肾脏缺血再灌注损伤中的表达及与肾脏损害程度的相关性。方法选用生后3～4周的雄性SD大鼠，随机分为正常组、假手术组、急性缺血再灌注损伤组。通过右侧。肾脏切除，无创动脉夹夹闭左侧肾动脉45min之后松开动脉夹，恢复肾脏血流，建立肾脏急性缺血再灌注损伤模型。并在恢复肾脏血流后12、24、36、48、72、96h取肾脏及血液样本。采用免疫组织化学方法及Western blot方法检测各组肾组织中β—arrestin2及LC3蛋白的表达水平，检测各组的肾功能，并对各组肾脏病理学进行评分。结果与正常组及假手术组相比，缺血再灌注损伤组血肌酐及肾脏病理学评分均有显著升高，其中肾脏损伤程度以缺血再灌注损伤后24h最为明显；β—arrestin2及LC3蛋白在正常组及假手术组。肾脏中的表达较少，在缺血再灌注损伤后的肾脏中表达显著升高，其中以缺血再灌注损伤后12h时表达上调最为显著；β—arrestin2及LC3的表达改变先于肾脏病理改变，并且与肾脏损害程度呈正相关（r=0．821，P〈0．05；r=0．913，P〈0．05）。结论在肾脏急性缺血再灌注损伤时，β—arrestin2可能作为一个上游调控蛋白，通过对自噬的调节参与急性。肾损伤的病理过程。

Objective To investigate the expression of β-arrestin2 and microtubule-associated protein light chain （LC） 3 in renal of rat with acute renal ischemia reperfusion injury, and to analyze the relationship between them and renal injury. Methods Fifty-four male SD rat（3-4 weeks old） were randomly divided into three groups： control group, sham group, acute ischemic reperfusion injury group. We established the acute renal ischemia reperfusion injury model through removing the right kidney and clamping the left renal for 45 minutes with noninvasive arterial clip. We obtained the kidney and blood samples respectively at 12 h, 24 h,36 h,48 h ,72 h,96 h after the surgery. Expressions of β-arrestin2 and LC3 protein were detected by the immunohistochemistry method and Western blot method. The renal function and morphological changes were assessed. Results Compared with control group and sham group, the serum creatinine and kidney pathological grading of acute ischemia reperfusion injury group obviously rised. The kidney injury was the most serious at the 24 h after acute ischemic reperfusion injury. The expressions of β-arrestin2 and LC3 were little in the control group and sham group. However, the expressions of these two indicators were obviously higher and reached the peak at the 12 h after acute ischemia reperfusion injury. All these results suggested that the changes of these two indicators were anterior to the histopathological changes. The expressions of β-arrestin 2 and LC3 protein were in positive correlation with the kidney injury （ r = 0. 821, P 〈 0. 05 ; r = 0. 913, P 〈 0. 05 ）. Conclusion In the acute renal ischemia-reperfusion injury, β-arrestin2 may be as a kind of upstream regulatory protein involving in the kidney pathological process through the regulation of the autophagy.