中文摘要：

目的探讨12．脂氧合酶（12-LO）对糖尿病性肾系膜细胞（MC）肥大的影响，及其发生机制。方法应用野生型（WT）及12-LO基因敲除小鼠诱导l型糖尿病模型，观察肾脏肥大及肾小球内p21及p27表达水平。采用总蛋白／细胞数的比值作为评价细胞肥大的指标，观察12-LO对高糖刺激引起的肾MC肥大的影响；利用实时定量PCR和Western印迹法观察12-LO及其代谢产物12羟二十烷四烯酸[12（S）-HETE]对MC内p21及p27表达的影响。结果12（S）-HETE能明显促进MC内p21基因表达（P〈0．05），增加p21与p27蛋白表达（P〈0．05），诱导细胞肥大（P〈0．05）。12-L0基因敲除抑制了高糖引起的MC肥大以及p21、p27表达增加（P〈0．05）；相反，细胞内高表达12-L0显著增加了p21与p27蛋白表达（P〈0．01）。糖尿病条件下12-L0基因敲除小鼠肾脏肥大的发生以及p21、p27在肾小球内的表达显著低于wT小鼠（P〈0．05）。结论12-LO通过影响p21、p27表达参与糖尿病性肾脏肥大的发生过程。

英文摘要：

Objective To explore the role of 12- lipoxygenase （12- LO） in the pathogenesis of diabetic renal mesangial cells （MC） hypertrophy and its related mechanisms. Methods WT and 12-LO knockout mice were induced as type 1 diabetes to investigate the renal hypertrophy and expression of p21, p27 in glomeruli. The ratio of total protein to cell number was detected as cellular hypertrophy diagnosis to explore the role of 12-LO in hyperglycemia induced mesangial cellular hypertrophy. Real-time PCR and Western blotting were used to detect the changes of p21 as well as p27 induced by 12（S）-HETE which was 12- LO metabolic product. Results 12（S）- HETE promoted p21 gene expression （P〈 0.05）, increased p21 and p27 protein levels in MC （all P 〈 0.05）, therefore induced cellular hypertrophy （P 〈 0.05）. MC from 12-LO knockout mouse showed less hypertrophy and decreased expression of p21 and p27 compared with WT MC under high glucose condition （all P〈0.05）. On the contrary, over- expression of 12- LO significantly enhanced p21 and p27 protein expression in MC （P 〈 0.01）. Compared to WT mice, 12- LO knockout mice showed less renal hypertrophy and decreased expression of p21 and p27 in glomeruli induced by hyperglycemia （all P 〈 0.05）. Conclusion 12-LO involves in the process of diabetic renal hypertrophy through regulating the expression of p21 and p27.