酪酸梭菌对坏死性小肠结肠炎新生鼠肠损伤的保护作用

摘要

Objective To explore the influence of Clostridium butyricum on the expression of vascular endothelial cell growth factor (VEGF) and its receptor 2 (VEGFR-2), proliferating cell nuclear antigen (PCNA), and tight junction protein claudin-2 in intestinal tissue in newborn rat with necrotizing enterocolitis (NEC). Methods Forty-eight-hour-old Sprague-Dewley (SD) rats were randomly divided into model group, control group, low-dose group, mid-dose group, and high-dose group, 12 rats each. Rats in each group were fed with milk substitute. The NEC model were created by hypoxia and cold stimulation for 3 consecutive days in model group, low-dose group, mid-dose group, and high-dose group. Meanwhile, low-dose group, mid-dose group, and high-dose group were intervened by being fed with Clostridium butyricum 0.2, 0.4, and 0.8 g/(kg·d), respectively. All rats in each group were sacriifced on day 4 and the intestines tissue was obtained. The pathological changes had been observed. The expression of VEGF, PCNA, and claudin-2 were detected by immunohistochemistry. The expression of VEGFR-2 was detected by RT-PCR. Results The intestines pathological scores was signiifcantly different among ifve groups (P< 0 . 05 ) with the scores being higher in model group than in low-dose group, mid-dose group, high-dose, group and control group, and being higher in all intervention groups than in control group (P all < 0 . 05 ). The expressions of VEGF, VEGFR-2 , and claudin-2 in model group were higher than those in all intervention groups and control group with them being higher in all intervention group than in control group (P all < 0 . 05 ). The expression of PCNA in model group was lower than those in all intervention groups and control group with it being lower in all intervention groups than that in control group (P all < 0 . 05 ). The expression of VEGF, VEGF-2 , PCNA, and claudin-2 were no different among intervention groups (P all > 0 . 05 ). Conclusion The expression of VEGF, VEGF-2 , and claudin-2 were higher in rats with NEC, while the expression of PCNA was lower. Supplementation of Clostridium butyricum may protect newborn rats by its act on these factors.%目的：探讨酪酸梭菌对坏死性小肠结肠炎（NEC）新生大鼠肠组织血管内皮细胞生长因子（VEGF）及其受体2（VEGFR-2）、增殖细胞核抗原（PCNA）及紧密连接蛋白claudin-2表达的影响。方法将出生48 h的SD新生大鼠随机分为模型组，对照组及低、中、高剂量组，每组12只。各组大鼠均以鼠乳代乳品喂养。模型组及低、中、高剂量组定时以缺氧和冷刺激连续3 d，建立NEC模型；低、中、高剂量组在建模的同时分别予酪酸梭菌0.2、0.4、0.8 g/(kg·d)。第4天处死大鼠取肠组织，观察病理变化，免疫组化法检测VEGF、PCNA及claudin-2蛋白表达，RT-PCR法检测VEGFR-2表达。结果各组间的肠组织病理评分差异有统计学意义（P< 0.05），模型组病理评分高于低、中、高剂量组及对照组，各干预组高于对照组，差异均有统计学意义（P< 0.05）；模型组VEGF、VEGFR-2和紧密连接蛋白claudin-2的表达高于各干预组及对照组，各干预组高于对照组，差异均有统计学意义（P< 0.05）；模型组PCNA表达低于各干预组及对照组，各干预组低于对照组，差异均有统计学意义（P< 0.05）；各干预组间VEGF、VEGFR-2、PCNA及claudin-2的表达两两比较差异无统计学意义（P> 0.05）。结论 NEC新生鼠VEGF、VEGFR-2和紧密连接蛋白claudin-2表达增高，PCNA表达降低；补充酪酸梭菌能作用于这些因子而对新生鼠起保护作用。