对比剂肾病大鼠肾脏组织caspase-12表达及意义

THE EXPRESSION AND SIGNIFICANCE OF CASPASE-12IN RATS WITH CONTRAST-INDUCED NEPHROPATHY

目的研究对比剂肾病大鼠肾脏中半胱氨酸天冬氨酸蛋白酶12（caspase-12）的表达情况,探讨细胞凋亡和内质网应激在对比剂肾病发生发展中的作用。方法将84只大鼠随机分为正常组（A组）、假手术组（B组）和模型组（C组）,各28只。C组大鼠经尾静脉先后注射吲哚美辛（INDO）、N-硝基-L-精氨酸甲酯（L-NAME）和760g/L泛影葡胺建立对比剂肾病大鼠模型;B组注射等量的INDO＋L-NAME＋生理盐水;A组注射等量磷酸盐缓冲液。各组分别于造模后12、24、48、72h处死大鼠,取血和肾组织,测定血尿素氮（BUN）、肌酐（Scr）,苏木精-伊红染色观察肾脏病理改变,免疫组化和Western-blot检测肾组织caspase-12蛋白表达,TUNEL染色检测肾脏细胞凋亡。结果 A组和B组大鼠不同时间点血BUN、Scr及caspase-12含量始终较低,肾组织无明显病理损伤和细胞凋亡,差异无统计学意义（P〉0.05）;同一时间点,C组血BUN、Scr含量较B组明显升高,差异有统计学意义（F=121.40～1 596.17,q=4.66～69.99,P〈0.05）。相同时间点,与B组相比,C组大鼠病理损伤较严重,肾组织中caspase-12表达明显升高,细胞凋亡明显,差异均有统计学意义（F=421.75～557.32,q=3.72～41.44,P〈0.05）。结论 caspase-12途径诱导的细胞凋亡可能参与对比剂肾病的发生发展,内质网应激可能通过增加caspase-12的表达参与对比剂肾病的发生。

Objective To investigate the expression of caspase-12 in kidney of rats with contrast-induced nephropathy（CIN）and evaluate the effects of apoptosis and endoplasmic reticulum stress on the occurrence and development of CIN. Methods Eighty-four Wistar rats were evenly randomized to three groups：normal control group（group A）,sham-operation group（group B）and CIN model group（group C）.The rats in group C were given indometacin（INDO）,L-NAME,and 760g/L of Urografin,one after another,trans caudal vein to create a CIN model in rats;those in group B were given equivalent volume of INDO,LNAME and NS,and those in group A received equivalent volume of phosphate buffer solution.The rats in each group were sacrificed at 12,24,48 and 72hours after completion of the models,blood and renal tissue were collected for blood urea nitrogen（BUN）and serum creatinine（Scr）detection,pathological changes of kidney were evaluated by HE staining.Expression of caspase-12 protein in kidney was detected using immuno-histochemistry and Western blotting.Apoptosis of tubular cells was detected with TUNEL staining. Results BUN,Scr and expression of caspase-12 of rats in groups A and B in different time points were low all the time,no obvious pathologic damages in kidney and apoptosis were noted（P〉0.05）,at the same time points,the levels of BUN and Scr in group C were much higher than that in group B,the difference was significant（F=121.40-1 596.17,q=4.66-69.99,P〈0.05）,the pathological changes in group C were more serious than that in group B,the expression of caspase-12 was higher,the apoptosis was notable（F=421.75-557.32,q=3.72-41.44,P〈0.05）. Conclusion Apoptosis induced by caspase-12 is probably involved in the occurrence and development of contrast-induced nephropathy,and endoplasmic reticulum stress involves in the occurrence of nephropathy is likely through increasing the expression of caspase-12.