CD105在评价腹膜透析腹膜新生血管中的应用价值

Association between CD105 and peritoneal angiogenesis in peritoneal dialysis rats

目的研究CD105在标记腹膜透析腹膜新生血管中的价值。方法 48只无特定病原体级雄性Sprague-Dawley大鼠,随机分入对照组(8只)、尿毒症组(8只)、正常腹透组(8只)和尿毒症腹透组(24只,再分为1、2、3亚组,每亚组8只)。采用尿毒症大鼠制作腹膜透析的动物模型。各组大鼠均留取脏层腹膜、壁层腹膜、肝脏皱褶,在电子显微镜下观察内皮细胞形态及其连接。各组大鼠处死前,取脏层腹膜标本予CD105免疫荧光染色并计算血管数。采用Western印迹法在蛋白水平检测腹膜血管内皮细胞生长因子受体(VEGFR)-2的表达量。结果 5/6肾切除术后12周,尿毒症组和尿毒症腹透组大鼠的血清尿素氮、血清肌酐、24h尿蛋白定量均较同组术前显著升高(P值均<0.01)。腹膜透析过程对实验大鼠的生化指标无明显影响;尿毒症腹透2亚组和尿毒症腹透3亚组腹透液留腹4h时的透出液肌酐与留腹前血浆肌酐的比值(4hD/Pcr)均显著高于对照组和尿毒症组(P值均<0.01),前两组间的差异无统计学意义(P>0.05),但均出现超滤衰竭。免疫荧光CD105染色结果示,尿毒症腹透1亚组的新生血管数显著多于对照组(P<0.05),尿毒症腹透2亚组显著多于正常腹透组和对照组(P值分别<0.05、0.01),尿毒症腹透3亚组显著多于尿毒症腹透1亚组(P<0.05)。尿毒症组与对照组间、尿毒症腹透3亚组与尿毒症腹透2亚组间新生血管数的差异均无统计学意义(P值均>0.05)。尿毒症腹透2亚组和尿毒症腹透3亚组大鼠的腹膜VEGFR-2蛋白相对表达量均显著高于对照组(P值均<0.05),而尿毒症腹透1亚组与其他组间的差异均无统计学意义(P值均>0.05)。结论 CD105可以作为腹膜透析腹膜新生血管较好的检测指标,为腹膜血管新生的评估、疾病严重程度的判断、治疗效果的评价提供新的有效的检测手段。

Objective To investigate the association between CD105 and peritoneal angiogenesis in uremic peritoneal dialysis （PD） rats. Methods Uremic （5/6 subtotal nephrectomy） rat models were established and divided into control group （n = 8）, uremic group （n = 8）, normal PD group （n =8） and uremic PD group （n = 24, further divided into 3 subgroups with 8 rats in each group）. Standard PD solution was applied in the study. Rats in the control group underwent sham operation but no PD. The visceral peritoneum, parietal peritoneum and liver folds were obtained to observe endothelial cells and their connections through electronic microscopy. Before rats were sacrificed, vessel density of visceral peritoneum was detected and quantified with anti-CD105 immunofluorescence staining. The expression of peritoneal vascular endothelial growth factor-receptor 2 （VEGFR-2） were examined by Western blotting. Results The serum creatinine, blood urea nitrogen and 24-hour urine protein were significantly increased in the rats of uremic group and uremia PD group 12 weeks after subtotal nephrectomy （all P^0.01）. Biochemical parameters was not significantly affected during dialysis; 4 hD/Pcr in uremic dialysis subgroup 2 and 3 were significantly higher than that in uremia group and control group （all P〈0.01）; there was no significant difference in 4 hD/Pcr between uremic dialysis subgroup 2 and subgroup 3 （ P〉0.05）, but ultrafiltraticn failure occurred in both subgroups. New vessels in uremic PD subgroup 1 was significantly more than that in the control group （P〈0.05）. New vessels in uremic dialysis subgroup 2 were significantly more than normal PD group and control group （P〈0.05, 0.01）. New vessels in uremic dialysis subgroup 3 were significantly more than uremic dialysis subgroup 1 （ P 〈 0. 05）. There were no significant differences in the number of new vessels between subgroup 2 and subgroup 3 （both P〉0.05） or between uremic group and control group （both P〉0.05）. The relative expression of VEGFR-2 protein in uremic PD subgroup 2 and 3 were significantly higher than that in the control group （both P〈0.05）. There were no significant difference in the expression of VEGFR-2 protein between uremic PD subgroup 1 and other groups （all P〉0.05）. Conclusion Increased expression of CD105 in the peritoneum is positively correlated with peritoneal angiogenesis. CD105 may be a new biomarker to stain the angiogenesis in the peritoneum.