高血糖对Wistar大鼠肾脏组织MMP-9mRNA、MMP-9蛋白表达的影响

Influence of high serum glucose on kidney expression of MMP-9 mRNA and MMP-9 protein in Wistar rats

目的:观察高血糖对Wistar大鼠肾脏基质金属蛋白酶9(MMP-9)mRNA、MMP-9蛋白表达的影响。方法:将40只雌性大鼠随机分为空白对照组(5只)和糖尿病组(DM组,35只)。糖尿病组用链脲佐菌素(STZ)一次性腹腔注射造模,造模成功后再次随机分组为5组,每组5只(余因造模未成功或死亡而被剔除)。5组分别为造模成功后第1天、第3天、第7天、第10天和第14天处死组,期间各组大鼠未予任何药物干预。处死大鼠后取其肾脏组织,用荧光定量PCR(FQ-PCR)法检测各组肾脏组织MMP-9mRNA的变化,免疫组化法观察肾小球基底膜区MMP-9蛋白变化。结果:①空白对照组和DM组大鼠肾脏组织中均有MMP-9mRNA表达,空白对照组与DM各组相比,MMP-9mRNA表达水平差异均无统计学意义(P>0.05)。血糖水平、高糖持续时间与MMP-9mRNA表达量均不相关。②免疫组化提示,DM组MMP-9蛋白在肾小球内主要表达于基底膜,以第7天处死组大鼠肾脏肾小球基底膜区MMP-9着色最强。定量分析示,第7天处死组大鼠肾脏肾小球基底膜区MMP-9蛋白水平达峰值,且血糖水平及高血糖持续时间与MMP-9蛋白水平呈正相关。结论:①DM大鼠肾脏组织内MMP-9mRNA不受血糖水平、高血糖持续时间等因素影响。②DM大鼠肾脏组织肾小球基底膜区MMP-9蛋白水平于成功造模后第7天第1次达峰值,且其MMP-9蛋白水平与血糖水平、高血糖持续时间呈正相关。

Objective To investigate the influence of high serum glucose on kidney expression of MMP-9 mRNA and MMP-9 in glomerular basement membrane in Wistar rats. Methods Forty healthy female Wistar rats were divided randomly into two groups： blank control group （n=5） and diabetes mellitus （DM） group （n=35）. Diabetes mellitus model was established by injection of streptozotocin （STZ） into the abdominal cavity. The DM group was divided into 5 subgroups randomly and were sacrificed on Day-1, Day-3, Day-7, Day-10 and Day-14 respectively. No medicine intervention was given to any group during this period before the animal was sacrificed. MMP-9 mRNA was determined by FQ-PCR and MMP-9 was determined by immunohistoehemistry method. Results ① Kidney tissues in both the blank control group and DM group had expression of MMP-9 mRNA, and no difference was observed between the two groups （P〉0.05）. Level of blood glucose and duration of high glucose had no correlation with MMP-9 mRNA. ②In the DM group, MMP-9 protein was expressed mainly in glomerular basement membrane. Day-7 subgroup showed the heaviest pigmentation, and quantitative analysis showed that the expression reached the peak in Day-7 subgroup. Level of blood glucose and duration of high glucose had a positive correlation with MMP-9. Conclusions ① Level of blood glucose and duration of high glucose has no influence on MMP-9 mRNA in kidney tissue of DM rats. ② Level of MMP-9 reaches its first peak on 7th day. MMP-9 is expressed mainly in the basement membrane zone. Level of MMP-9 has a positive correlation with level of blood glucose and duration of high glucose.