Tumstatin肽对视网膜微血管内皮细胞增殖及ERK蛋白表达的影响

目的 观察Tumstatin肽对体外培养的视网膜微血管内皮细胞增殖及细胞外信号调节激酶(ERK) 蛋白表达的影响。方法　采用MTT比色法测定Tumstatin肽（T8肽）对血管内皮生长因子（VEGF）诱导下的恒河猴视网膜血管内皮细胞（RF/6A细胞）增殖的干预作用；采用Western-blot检测T8肽对VEGF刺激后15min、30min、45 min和60min的RF/6A细胞ERK1/2蛋白表达水平的变化。 结果　T8肽浓度在5μg/ml 以上时对RF/6A细胞有抑制作用，且抑制作用随着浓度的增大而增高，各组OD值和抑制率比较差异均有显著性意义（P均<0.05）；T8肽可抑制VEGF对RF/6A细胞的促增殖作用；在1～40μg /ml相同浓度条件下，T8肽对VEGF条件下的RF/6A细胞增殖抑制率显著大于无VEGF条件下的抑制率（P均<0.01）。VEGF可刺激RF/6A细胞ERK1/2蛋白表达增加，T8肽可抑制VEGF诱导的RF/6A细胞ERK1/2蛋白的表达。 结论　Tumstatin抑制视网膜微血管内皮细胞的增殖，机制可能与VEGF信号转导通路上的ERK1/2细胞信号转导通路有关。

The effect of tumstatin peptide on the proliferation and the expression of extra-cellular signal-regulated protein kinase in retinal microvascular endothelial cells

Objective　To observe tumstatin peptide on the proliferation and the expression of extra-cellular signal-regulated protein kinase (ERK) in retinal microvascular endothelial cells. Methods　MTT assay was used to examine tumstatin’s interfering effect on proliferation induced by vascular endothelial growth factor(VEGF) in RF/6A cells (Cell line of retinal microvascular endothelial cell of Macaca rhesus). The expression of ERK1/2 15, 30, 45 and 60 minutes after the treatment of tumstatin peptide (T8 peptide) and VEGF were detected by Western blotting. Results 　Different concentrations of tumstatin peptide (T8 peptide) including 5μg /ml, 10μg /ml, 20μg/ml and 40μg /ml could inhibit the growth of RF/6A, and cellular growth decrease gradually along with the increase of tumstatin concentration(P<0.05). T8 peptide could inhibit proliferation of RF/6A cells induced by VEGF, its inhibitory effect increased along with the elevation of the concentration of T8 peptide（P<0.01）The protein expression of ERK1/2 increased rapidly by the stimulation of VEGF. Tumstatin can inhibit the expression of ERK1/2 induced by VEGF in RF/6A cells. Conclusions Tumstatin can inhibit proliferation of　retinal microvascular endothelial cells, and this effect is related with the signal path through ERK1/2 .