摘要
目的探讨组织型转谷氨酰胺酶(tTG)在糖尿病(DM)大鼠肾组织中的表达及其意义。方法链脲佐菌素(STZ)诱发大鼠制备DM模型,分别于第30、60、90和120天处死DM组大鼠6只、对照组(C组)3只。测定尿白蛋白量(AER)、肾重指数和血肌酐(Scr)。HE染色和PASM染色观察肾组织病理变化。免疫组织化学检测肾脏胶原Ⅳ(ColⅣ)和可溶性tTG表达。间接免疫荧光检测不溶性tTG分布。用RT-PCR检测总tTG mRNA表达。结果各个时间点DM组大鼠的AER、肾重指数和Scr均较c组明显升高(P<0．05,P<0．01)。DM组ColⅣ、可溶性tTG和不溶性tTG蛋白的表达均较C组明显增多(P<0．05,P<0．01),且均随病程进展呈上升趋势。可溶性tTG和不溶性tTG蛋白水平都与AER呈正相关(r=0．937和0．809,P均<0．01)。DM大鼠肾小球系膜区ColⅣ和不溶性tTG蛋白表达增加部位一致,且两者水平显著正相关(r=0．831, P<0．05)。DM组总tTG mRNA的表达从第30天起开始上升、第90天达高峰,第120天稍下降。结论tTG在DM大鼠肾组织的过度表达及不溶性tTG与ColⅣ表达的正相关,提示tTG可能参与了早期糖尿病肾病(DN)的发病过程。
Objective To observe the expression of tissue transglutaminase （tTG） in renal tissues of diabetic nephropathy rats, and to investigate its contribution to the progression of diabetic nephropathy. Methods Streptozotocin-induced diabetic rats were sacrificed at 30 d, 60 d, 90 d, and 120 d respectively. Albuminuria excretion rate （AER）, kidney weight index and serum creatinine （Scr） of the rats were measured. Hematoxylin and eosin （HE） staining and periodic acidsilver-methenamine （PASM） sta/nlng were used to observe the renal pathological changes. Collagen IV （Col Ⅳ ） and soluble tTG protein in kidney were examined by immunohistochemistry,insoluble tTG by immunofluorescenee. Expression of total tTG mBNA in kidney was detected by reverse transcriptionpolymerase chain reaction （RT-PCR）. Results AER, kidney weight index and Scr of diabetic rats were all progressive during the period of the experiment. Compared with control group, the levels of Col IV, soluble tTG and insoluble tTG protein in kidneys of hyperglycemic rats were significantly increased at 30 d, 60 d, 90 d and 120 d（P〈 0.05,P〈 0.01）.During the whole course, levels of Col IV ,soluble tTG and insoluble tTG of kidneys from diabetic rats increased gradually.Both soluble tTG expression and insoluble tTG expression were posifivdy correlated with AER （ r=0.937,P 〈 0.01 and 0.809,P〈 0.01）. The location of increased Col IV in the glomeruli was the same as that of increased insoluble tTG in the mesangium, and the correlation coefficients of insoluble tTG and Col Ⅳ was 0.831 （P 〈 0.05）. Total tTG mRNA levels started to rise in diabetic kidneys at 30 d, reaching its peak at 90 d, and reduced slightly at 120 d. Conclusion The over-expression of tTG protein and the change of total tTG mRNA levels in the diabetic kidney, and the positive correlation of insoluble tTG and Col Ⅳ in glomeruli demonstrates that tTG may play a role in the progression of early diabetic nephropathy.
出处
《中华肾脏病杂志》
CAS
CSCD
北大核心
2006年第9期559-563,共5页
Chinese Journal of Nephrology
基金
辽宁省教育厅高等院校科研攻关计划资助项目(20040105)
