促红细胞生成素衍生肽对动脉粥样硬化心肌缺血大鼠新生血管密度及VEGF/VEGFR通路的影响

Influence of helix B surface peptide on microvessel density and VEGF/VEGFR pathway in rats with atherosclerotic myocardial ischemia

目的探讨促红细胞生成素衍生肽(HBSP)对动脉粥样硬化心肌缺血大鼠血管内皮细胞生长因子(VEGF)/血管内皮细胞生长因子受体(VEGFR)通路及新生血管密度的影响。方法将40只SD大鼠随机分为:对照组、模型组、阳性对照组、HBSP低、中、高剂量组,除对照组外,其余组大鼠构建动脉粥样硬化心肌缺血模型。HBSP低、中、高剂量组分别于大鼠腹腔注射25μg/kg、50μg/kg、100μg/kg HBSP,阳性对照组给予灌胃辛伐他丁2 mg/kg,对照组和模型组大鼠腹腔注射等量生理盐水。给药24 h后,检测各组大鼠血清总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)水平,用ELISA法检测各组大鼠血清中炎性因子C反应蛋白(CRP)、白介素6(IL-6)、肿瘤坏死因子α(TNF-α)的表达水平,免疫组化CD31染色观察新生血管密度;Western blot法检测各组大鼠主动脉组织中VEGF、VEGFR2蛋白表达水平。结果与对照组相比,模型组大鼠血清中TC、TG、LDL-C水平、CRP、IL-6、TNF-α含量、主动脉组织中CD31 MOD及主动脉组织中VEGF、VEGFR2蛋白表达水平显著升高(P<0.05),HDL-C水平显著降低(P<0.05);与模型组相比,HBSP低、中、高剂量组鼠血清中TC、TG、LDL-C水平、CRP、IL-6、TNF-α含量、主动脉组织中CD31 MOD及主动脉组织中VEGF、VEGFR2蛋白表达水平显著降低(P<0.05),HDL-C水平显著升高(P<0.05);与阳性对照组相比,HBSP低、中剂量组鼠血清中TC、TG、LDL-C水平、CRP、IL-6、TNF-α含量、主动脉组织中CD31 MOD及主动脉组织中VEGF、VEGFR2蛋白表达水平显著升高(P<0.05),HDL-C水平显著降低(P<0.05);与HBSP低、中剂量组相比,HBSP高剂量组鼠血清中TC、TG、LDL-C水平、CRP、IL-6、TNF-α含量、主动脉组织中CD31 MOD及主动脉组织中VEGF、VEGFR2蛋白表达水平显著降低(P<0.05),HDL-C水平显著升高(P<0.05)。结论HBSP可以通过调控VEGF/VEGFR通路,降低新生血管密度,抑制动脉粥样硬化心肌缺血大鼠血管新生。

Objective To discuss the influence of helix B surface peptide(HBSP)on pathway of vascular endothelial growth factor(VEGF)/vascular endothelial growth factor receptor(VEGFR)and microvessel density(MVD)in rats with atherosclerotic myocardial ischemia.Methods SD rats(n=40)were randomly divided into control group,model group,positive control group and low-dose,mid-dose and high-dose HBSP groups.Except control group,the model of atherosclerotic myocardial ischemia was established in all groups.HBSP groups were given injection of HBSP in 25μg/kg,50μg/kg and 100μg/kg respectively,positive control group was orally given simvastatin(2 mg/kg),and control group and model group were given injection of equivalent normal saline.After 24 h,the levels of TC,TG,LDL-C and HDL-C were detected by using automatic biochemical analyzer.The expressions of CRP,IL-6 and TNF-αwere detected by using ELISA,and MVD was observed through CD31 immunohistochemical staining.The protein expressions of VEGF and VEGFR2 were detected by using Western blotting assay.Results Compared with control group,the levels of TC,TG,LDL-C,CRP,IL-6 and TNF-α,and expressions of CD31 mean optical density(MOD),VEGF and VEGFR2 increased significantly(P<0.05),and HDL-C level decreased significantly(P<0.05)in model group.Compared with model group,the levels of TC,TG,LDL-C,CRP,IL-6 and TNF-α,and expressions of CD31 mean optical density(MOD),VEGF and VEGFR2 decreased significantly(P<0.05),and HDL-C level increased significantly(P<0.05)in low-dose,mid-dose and high-dose HBSP groups.Compared with positive control group,the levels of TC,TG,LDL-C,CRP,IL-6 and TNF-α,and expressions of CD31 mean optical density(MOD),VEGF and VEGFR2 increased significantly(P<0.05),and HDL-C level decreased significantly(P<0.05)in low-dose and mid-dose HBSP groups.Compared with low-dose and mid-dose HBSP groups,the levels of TC,TG,LDL-C,CRP,IL-6 and TNF-α,and expressions of CD31 mean optical density(MOD),VEGF and VEGFR2 decreased significantly(P<0.05),and HDL-C level increased significantly(P<0.05)in high-dose HBSP group.Conclusion HBSP can inhibit angiogenesis through regulating VEGF/VEGFR pathway and reducing MVD in rats with atherosclerotic myocardial ischemia.