微生态制剂对坏死性小肠结肠炎大鼠肠上皮细胞凋亡和增殖的影响

Effects of probiotics on apoptosis and proliferation of intestinal epithelial cells in rats with necrotizing enterocolitis

目的研究复方嗜酸乳杆菌对坏死性小肠结肠炎大鼠肠上皮细胞凋亡及增殖细胞核抗原(PCNA)表达的影响,为应用复方嗜酸乳杆菌防治新生儿坏死性小肠结肠炎(NEC)提供参考。方法36只出生48 h新生SD大鼠,采用随机数字表法分为正常组、模型组、干预组,每组12只。采用缺氧加冷刺激3 d建立NEC模型,干预组在建模同时给予复方嗜酸乳杆菌;于模型建立后禁食12 h处死所有大鼠,剖取其肠组织采用原位末端标记法(terminal-deoxynucleoitidyl transferase mediated nick end labeling,TUNEL)测定细胞凋亡情况,采用实时荧光定量PCR检测大鼠肠组织中PCNA基因表达情况。结果1.大鼠肠组织细胞凋亡的检测结果:模型组、正常组、干预组凋亡指数分别为(88.33±2.77)%、(4.75±0.75)%、(44.41±4.81)%,各组间两两比较差异均有统计学意义(均P<0.05)。2.大鼠肠组织中PCNA基因表达结果:模型组、正常组、干预组PCNA基因mRNA表达水平分别为(9.28±3.26)×10^-4、(15.35±1.91)×10^-4、(12.09±3.06)×10^-4,各组间两两比较差异均有统计学意义(均P<0.05)。结论NEC时新生大鼠肠上皮细胞凋亡增加,PCNA表达减少;复方嗜酸乳杆菌能减少细胞凋亡,促进肠上皮细胞增殖,可能有助于降低新生大鼠发生NEC的风险及严重程度。

Objective To study the effect of compound Lactobacillus acidophilus on the apoptosis of intestinal epithelial cells and expression of proliferating cell nuclear antigen(PCNA)in rats with necrotizing enterocolitis,so as to provide some theoretical reference for the application of compound Lactobacillus acidophilus in the prevention and treatment of necrotizing enterocolitis(NEC)for newborn infants.Methods Thirty-six 48-hour old newborn SD rats were randomly divided into normal group,model group and intervention group,with 12 rats in each group.The NEC model was established by hypoxia and cold stimulation for 3 days,and the intervention group was given the compound Lactobacillus acidophilus at the same time;after the model was established,all the rats were sacrificed after 12 hours of fasting and their intestinal tissues were excised by terminal-deoxynucleoitidyl transferase mediated nick end labeling(TUNEL)method to determine the condition of apoptosis and to detect expression of the PCNA gene in the intestinal tissues by fluorescent quantitative PCR.Results(1)The apoptosis rates of the intestinal tissues:in the model group,the normal group and the intervention group were(88.33±2.77)%,(4.75±0.75)%and(44.41±4.81)%,respectively,and the differences had statistical significance(all P<0.05).(2)The PCNA expression in the intestinal tissue by real-time PCR in the model group,normal group and intervention group were(9.28±3.26)×10^-4,(15.35±1.91)×10^-4 and(12.09±3.06)×10^-4,respectively,and the differences had statistical significance(all P<0.05).Conclusions The apoptosis rate of intestinal epithelial cells increases and PCNA expression decreases when NEC occurs.Compound Lactobacillus acidophilus can reduce apoptosis,promote intestinal epithelial cell proliferation,and thus help to reduce the risk and severity of NEC in neonatal rats.