摘要
目的 观察Kkay小鼠糖尿病肾病(DN)时肾脏基质金属蛋白酶9(MMP-9) 的表达,并探讨其细胞内信号传导机制。 方法 Kkay糖尿病小鼠(KA)组和非糖尿病小鼠(KB)组各8 只,以PAS染色、免疫组化和逆转录聚合酶链反应(RT PCR)观察肾脏病变、MMP-9 表达水平。经糖基化终末产物(AGEs)作用于脐静脉内皮细胞(HUVECs)后,分别以RT PCR 和流式细胞技术检测MMP-9表达;以凝胶阻滞电泳(EMSA)检测核转录因子κB(NF-κB)激活情况。 结果 KA组出现明显DN病变,其肾小球硬化指数(GI)明显高于KB组(P<0.05);KA组肾小球MMP 9阳性着色面积(11 14%)高于KB组(5 68%)(P<0.01),MMP-9 mRNA表达水平有类似变化。AGEs使HU-VECs MMP-9表达增强,并伴有NF-κB激活。抑制NF-κB活性可降低MMP-9表达。 结论 Kkay小鼠DN伴有MMP-9表达增高,推测MMP-9在DN发生发展中起一定作用;AGEs可能是通过激活NF κB使内皮MMP-9表达增强的。
Objective To study the expression of MMP-9 in the diabetic nephropathy of Kkay mice and its intracellular signal transduction pathway. Methods Kkay diabetic (KA) and (non-diabetic) mice (KB) were sacrificed for renal pathological examination by PAS.The expression of MMP-9 in kidney was detected by immunohistochemical staining and RT-PCR. After HUVECs ((human) umbilical vein endothelial cells) were incubated with AGEs, RT-PCR and flow cytometric (assay) were performed to observe the expression of MMP-9. The binding activity of nuclear factor of kappa B (NF-κB) was (investigated) by electrophoretic mobility shift assays (EMSA). Results The glomerulosclerosis index (GI) in KA was much higher than that in KB group. The higher expressions of MMP-9 protein and mRNA in KA group were showed. AGEs increased the expression of MMP-9 in HUVECs,which was associated with the activation of NF-κB. When NF-κB binding activity was (inhibited,) the expression of MMP-9 decreased. Conclusions MMP-9 expression in diabetic (nephropathy) is enhanced, which may be related to the development of nephropathy. AGEs could (enhance) the expression of MMP-9 in HUVECs,which is associated with the activation of NF-κB.
