沙立度胺抑制缺氧所致胃肠道血管发育不良的机制初探

目的 探讨沙立度胺抗血管生成的作用机制.方法 收集胃肠道血管发育不良患者手术切除的肠段标本,免疫组化检测病变肠段的血管内皮生长因子(VEGF)表达.体外缺氧条件下培养人脐静脉内皮细胞至对数生长期,随机分为6组,同步化后用不同浓度沙立度胺(40、60、80、100μ/ml)刺激72 h.ELISA和实时定量PCR法测定VEGF的表达,Western blot法测定低氧诱导因子1α(HIF-1α)的表达.结果 免疫组化结果显示,病变肠段血管扩张、扭曲,VEGF的表达明显增强.ELISA检测表明,缺氧培养条件下细胞上清中VEGF蛋白表达水平明显高于常氧状态(1199.3±61.4)ng/L比(864.7±41.2)ng/L,P<0.05];沙立度胺可有效抑制缺氧条件下人脐静脉内皮细胞的VEGF蛋白表达.实时定量PCR结果亦提示沙立度胺能明显抑制缺氧状态下VEGF mRNA的表达(P<0.05).Western blot结果表明,沙立度胺可抑制缺氧状态下VEGF的上游调节因子HIF-1α的表达,且这一抑制作用呈剂量相关性.结论 初步体外研究表明,沙立度胺通过抑制缺氧条件下人脐静脉内皮细胞HIF-1α及VEGF的表达,从而抑制血管生成,是其有效治疗血管发育不良所致消化道出血的可能机制之一.

The mechanisms of thalidomide in treatment of angiodysplasia due to hypoxia

Objective To investigate the inhibitory effect of thalidomide on angiodysplasia.Methods Excisional intestinal specimens were collected and immunohistochemical examination was carried out.The human umbilical vein endothelial cells were cultured in vitro to exponential phase of growth,divided into six groups and synchronized for 24 hours.They were then stimulated with thalidomide (40-100 μg/ml) for 72 hours.MTT assay was used to assess cellular proliferation.ELISA,real-time quantitative PCB and western blot were applied to detect the expression of VEGF/HIF-1α of human umbilical vein endothelial cells (HUVEC).Results Immunohistochemical analysis of intestinal pathological specimens demonstrated higher expression of VEGF.ELISA showed that the expression of VEGF under hypoxia was obviously higher than that under normoxia ( 1199.3 ± 61.4) ng/L vs ( 864.7 ± 41.2 ) ng/L,P < 0.05 ].Real-time quantitative PCR and Western blot discovered that thalidomide inhibited the expression of VEGF/ HIF-1α of HUVEC (P < 0.05).The effect of thalidomide was dose-dependent.Conclusions Thalidomide can suppress the expression of HIF-1α and VEGF in HUVEC in vitro and then inhibit angiodysplasia,which may play a significant role in stopping the rebleeding in patients with recurrent gastrointestinal bleeding.