可溶性Tie2融合蛋白对尿毒症腹膜透析大鼠血管新生的影响

Effect of soluble Tie2 fusion protein on peritoneal angiogenesis in uremic peritoneal dialysis rats

目的观察可溶性Tie2融合蛋白（sTie2／Fc）对尿毒症腹膜透析大鼠腹膜血管新生的影响。方法48只雄性SD大鼠，按随机数字表法分为以下6组：正常对照组、假手术组、尿毒症非腹透组、4．25％腹透组、sTie2／Fc2．5μg／kg干预组、sTie2／Fc5．0pog／kg干预组。腹透组按照4．25％腹透液30ml／kg大鼠体质量规律腹透28d。规律腹透期间，干预组给予sTie2／Fc隔天1次皮下注射，共计14次。28d后留取各组大鼠腹膜组织，分别用RT—PCR和免疫组织化学染色法检测腹膜组织血管生成素2（Angpt-2）mRNA和蛋白的表达。CD34染色观察腹膜组织毛细血管密度（MVD）。结果各组大鼠腹膜组织均表达Angpt-2；尿毒症非腹透组、4．25％腹透组Angpt-2mRNA、蛋白表达均显著高于正常对照组（均P〈0．05）；4．25％腹透组Angpt-2mRNA、蛋白表达显著高于尿毒症非腹透组（均P〈0．05）；sTie2／Fc2．5μg／kg干预组、sne2／n5．0μg／kg干预组Angpt-2mRNA、蛋白表达均显著低于4．25％腹透组（均P〈0．05）。尿毒症非腹透组、4．25％腹透组腹膜组织MVD均显著高于正常对照组（均P〈0．05）；sTie2／Fc2．5μg／kg干预组、sTie2／Fc5．0μg／kg干预组腹膜组织MVD均显著低于4．25％腹透组（均P〈0．05）。结论sTie2／Fc可以抑制尿毒症腹膜透析大鼠腹膜新生血管的形成，阻断配体介导的信号传导通路可能是其抑制腹膜血管形成的机制之一。

Objective To investigate the effect of soluble Tie2 fusion protein （sTie2/Fe） on the angiogenesis of peritoneal vessels in uremic peritoneal dialysis （PD） rats. Methods Rats were randomly divided into 6 groups： normal rats as control group （groupl）, rats with sham operation （group2）, uremic rats without PD （group3）, uremie rats dialyzed with 4.25% PD solution （group4）, uremic rats dialyzed with 4.25% PD solution and treated by subcutaneous injection of 2.5 μg/kg sTie2/Fc （group5）, uremic rats dialyzed with 4.25% PD solution and treated by subcutaneous injection of 5.0 μg/kg sTie2/Fc （group6）. sTie2/Fc was given every other day during peritoneal dialysis period, total 14 doses. After regular PD for 28 days, RT-PCR and tissue immunohistochemical staining were used to detect the mRNA and protein expressions of Augpt-2 in peritoneal tissues in each group of rats. Microvessel density （MVD） of peritoneum was detected and quantified with immunohistochemical staining by using anti-CD34 antibody. Results The expression of Angpt-2 mRNA and protein was found in each group. There was no significant difference of Angpt-2 expression both in mRNA and protein level between groupl and group2.Compared with groupl, the mRNA and protein expression of Angpt-2 were significantly increased in group3 and group4 （all P〈0.05）. Compared with group3, the mRNA and protein expression of Angpt-2 were significantly increased in group4 （all P〈0.05）. Compared with group 4, the mRNA and protein expression of Angpt-2 were significantly decreased in group5 and group6 （all P〈.05）. Compared with group5, the mRNA and protein expression of Angpt-2 were significantly decreased in group6 （all P〈0.05）. Only few new microvessel was found in groupl and group2. Compared with groupl, MVD was significantly up-regulated in group3 and group4 （all P〈0.05）. Compared with group4, MVD was ,signifieantly down-regulated in group5 and group6 （all P〈0.05）. Conclusions Peritoneum neoangiogensis can be effectively inhibited by sTie2/Fc in uremic rat treated with PD. Blocking of signal transduction may be involved in the mechanism of sTie2/Fe inhibiting peritoneal angiogenesis.