高糖上调大鼠主动脉平滑肌细胞骨桥蛋白表达

High glucose induces up-regulation of osteopontin in rat aortic vascular smooth muscle cells

目的探讨高糖对大鼠血管平滑肌细胞(VSMCs)骨桥蛋白(OPN)表达的影响及机制。方法 SD大鼠腹腔注射链脲佐菌素复制1型糖尿病模型,免疫组化、RT-PCR和Western blot检测大鼠主动脉OPN和PCNA的表达;大鼠主动脉VSMCs经含正常糖(5.5 mmol/L)、高糖(25 mmol/L)、甘露醇(25 mmol/L)、高糖+GF109203X(蛋白激酶C抑制剂,10μmol/L)、高糖+NAC(NF-κB抑制剂,10μmol/L)的DMEM处理48 h,免疫荧光及Western blot检测OPN的表达,Western blot分析PCNA、PKC和P65的表达。结果高糖血症大鼠主动脉VSMCs高表达OPN及PCNA。原代VSMCs经高糖刺激后OPN、PCNA、PKC及P65表达明显增加;GF109203X和NAC均可下调PCNA的高表达,但仅GF109203X抑制高糖诱导的OPN高表达。结论高糖可能通过激活PKC信号诱导OPN表达并促进VSMCs增殖,从而在糖尿病性血管并发症中起作用。

Objective To investigate the effects and mechanism of high glucose on the osteopontin（OPN） expression in rat aortic vascular smooth muscle cells（VSMCs）.Methods SD rats were intraperitoneally injected with streptozotocin,OPN and PCNA expression in rat thoracic aortas were detected by immunohistochemical staining,RT-PCR and Western blot analysis;After primary rat aortic VSMCs treated with DMEM medium supplemented with normal glucose（5.5 mmol/L）,high glucose（25 mmol/L）,mannitol（25 mmol/L）,high glucose ＋ GF109203X（PKC inhibitor,10 μmol/L） and high glucose ＋ NAC（NF-κB inhibitor,10 μmol/L） for 48 h,OPN expression was examined by immunofluorescence and Western blot,expression of PCNA,PKC and P65 were assessed by Western blot analysis.Results OPN and PCNA expression increased in hyperglycemic rat aortic VSMCs.Expression of OPN,PCNA,PKC and P65 were significantly up-regulated in VSMCs exposed to high glucose.Expression of PCNA was attenuated by GF109203X and NAC in high glucose-treated VSMCs,while the expression of OPN was only inhibited by GF109203X.Conclusion High glucose induces OPN expression and cell proliferation in VSMCs and may be explained by activation of PKC signal,which play a critical role in diabetic vascular complications.