摘要
目的探讨血管生成素（Ans）及其受体（Tie-2）和血管内皮生长因子（VEGF）在糖尿病肾脏中的表达变化规律。研究其与肾脏微血管结构变化的关系。方法将雄性成年SD大鼠分成糖尿病组和对照组，糖尿病组采用链脲佐菌素（SV-Z）腹腔注射造模。采用RT-PCR以及免疫组化技术。连续多时点观察肾脏Ang-1、Ang-2、Tie-2、VEGF以及血栓调节蛋白（TM-1）mRNA和蛋白表达变化规律，并分析其相关性。结果（1）糖尿病组Ang-1 mRNA于第4、8周时显著上调（吸光度A．83．58＋10．23、88．59±6．97），第24周时低于对照组（47．13±8．02比64．53±8．77，P〈0．05）。免疫组化显示Ang．1突出表达于肾小球，糖尿病组第4周后肾小球阳性染色明显强于对照组（A对数值，4周1．64±0．12比1．08±0．16，24周1．24±0．11比1．11±0．17）。（2）糖尿病组Tie-2mRNA在4～16周显著高于对照组（A，4周87．31±11．69比63．62±5．61，16周81．75±8．58比60．15±2．66）。免疫组化显示Tie-2突出表达于肾小球，糖尿病组各时点均显著高于对照组，高峰在4～8周。（3）糖尿病组仅在第16和20周时检测到明显的Ang-2mRNA表达。免疫组化显示12周后仅在皮质区肾小管周围有Ang．2染色的微血管，而在第16周时最明显。（4）糖尿病组2～20周时肾小球TM-1染色显著高于对照组（A对数值，2周0．99±0．15比0．68±0．17，20周1．03±0．17比0．74±0．13），第24周时低于对照组，但差异无统计学意义。（5）糖尿病组VEGFmRNA和蛋白表达均较对照组明显升高。（6）糖尿病组Ang-1、Tie-2、VEGF和TM-1相互间均呈正相关。它们与尿蛋白、肾重／体重、肾小球体积、肾小球面积也均呈正相关。结论（1）糖尿病肾脏存在VEGF、Ang及Tie-2表达的改变，早期Ang-1、Tie-2表达上调，后期下调并伴Ang-2表达上调。（2）Ang、Tie及VEGF的改变与糖尿病肾脏新生血管生成有关，其Ang-1下调和VEGF、Ang-2上调起重要作用。（3）糖尿病肾脏中后期皮质区肾小管周围已有Ang-2染色的新生微血管生成。
Objective To observe the expressive changes of angiopoietins（Ang）/Tie-2 axis and vascular endothelial growth factor （VEGF） in kidney tissue and examine the correlation of Ang/ Tie-2 axis and VEGF with renal microvascular disease in diabetic rats. Methods SD male rats were randomly divided into streptozotocin-induced diabetes group and control group. The mRNA and protein expression of Ang-1, Ang-2, Tie-2, VEGF and thrombomedulin-1 （TM-1）in kidney tissue of two groups was examined by RT-PCR and immunohistochemistry at week 2, 4, 8, 12, 16, 20, and 24 respectively. Results （1） Ang-1 mRNA in diabetic group was up-regulated significantly at week 4 and 8（A ,83.58±10.23,88.59±6.97）, but down-regulated significantly at week 24（47.13±8.02 vs 64.53±8.77）, as compared with other time points of diabetic group and the same time points of control group. Ang-1 was expressed outstandingly in glomeruli. From week 4 to week 24, the protein expression of Ang-1 in diabetic glomeruli increased significantly （lgA, 1.64±0.12 vs 1.08 ±0.16,at week 4,1.24±0.11 vs 1.11±0.17 at week 24）. （2） From week 4 to week 16, Tie-2 mRNA in diabetic group was up-regulated obviously with the peak between week 8 and week 12 （A ,87.31±11.69 vs 63.62±5.61 at week 4,81.75±8.58 vs 60.15＋2.66 at week 16）. The protein expression of Tie-2 was found mainly in glomeruli. Throughout experimental period, the expression of Tie-2 staining in diabetic glomeruli increased apparently with the peak between week 4 and week 8. （3） Ang-2 mRNA in diabetic group was found only at week 16 and week 20. The expression of Ang-2 in peritubular microvessel of diabetic renal cortex was found from week 12 to week 24 with the peak at week 16.（4）compared with control group,TM-1 staining in diabetic glomeruli is much more from week 2 to week 20 （lgA ,0.99±0.15 vs 0.68±0.17 at week 2,1.03±0.17 vs 0.74±0.13 at week 20）,but a little lower at week 24. （5） The expression of VEGF increased significantly in diabetic group. （6） In diabetic group, correlations were significantly positive among Ang-1, Tie-2, VEGF and TM-1. Meanwhile, they were positively correlated with kidney/body weight, glomerular volume, glomerular area, and urine protein excretion respectively. Conclusions （1） Change of Ang/Tie-2 axis exists in diabetic kidney, which Ang-1 and Tie-2 expression is up-regnlated in early stage and downregulated along with Ang-2 up-regulation in later stage.（2） In diabetic kidney, the change of Ang/ Tie-2 axis is partly associated with the renal angiogenesis which is mainly responsible for Ang-1 down-regulation and VEGF, Ang-2 up-regnlation. （3） There is a formation of new peritubular microvessels at diabetic renal cortex in middle and later stages.
出处
《中华肾脏病杂志》
CAS
CSCD
北大核心
2006年第9期521-527,共7页
Chinese Journal of Nephrology
基金
四川省科技厅攻关重点项目(05SG022-018-4)
