双歧杆菌对断奶前大鼠肠道损伤中防御素-5表达的影响。

Effect of bifidobacterium on defensin-5 expression in intestinal injury of preweaning rats.

作者信息

Wang Wei, Yang Shu-Fen, Ren Li-Hong, Zhang Xiu-Xiu, Yu Shui-Lian

机构信息

Wei Wang, Shu-Fen Yang, Li-Hong Ren, Xiu-Xiu Zhang, Shui-Lian Yu, Department of Pediatrics, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, Heilongjiang Province, China.

出版信息

World J Gastroenterol. 2015 Mar 7;21(9):2638-44. doi: 10.3748/wjg.v21.i9.2638.

DOI:10.3748/wjg.v21.i9.2638

PMID:25759531

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4351213/

Abstract

AIM

To investigate the protective effect of bifidobacterium in endotoxin-induced intestinal injury in preweaning rats.

METHODS

Preweaning rats were randomly divided into three groups (n = 40 for each): a control group (group C), a model group (group E) and a treatment group (group T). Both groups E and T were intraperitoneally injected with lipopolysaccharide (LPS) at a dose of 5 mg/kg (5 mg/L in normal saline), and group T was intragastrically administrated with bifidobacterium suspension (2.0 × 10(9) CFU/mL, 0.5 mL each time, twice a day, until the end of the experiment) 7 d before LPS administration. Group C was intraperitoneally injected with normal saline. After intraperitoneal injection and intragastric administration, the rats were placed back to the initial cage to receive breast feeding. The rats were killed at 2, 6, 12, 24 or 72 h, respectively, after endotoxin or physiological saline injection to collect serum and ileal tissue samples. Myeloperoxidase (MPO) contents in serum and ileum were detected at different times, and expression of ileal defensin-5 mRNA was evaluated by reverse transcription-polymerase chain reaction.

RESULTS

Serum and ileal MPO contents in group E were significantly higher than those in group C (serum contents: 107.50 ± 17.70 vs 157.14 ± 24.67, P < 0.05; ileal contents: 1.03 ± 0.21 vs 1.57 ± 0.33, P < 0.05), which peaked at 12 h and 6 h, respectively. MPO contents in group T were significantly lower than those in group E (serum contents: 114.38 ± 24.56 vs 145.25 ± 23.62, P < 0.05; ileal contents: 1.25 ± 0.24 vs 1.57 ± 0.33, P < 0.05). The expression of defensin-5 mRNA in group E was significantly higher than that in group C (0.953 ± 0.238 vs 0.631 ± 0.146, P < 0.05), which peaked at 2 h, and then decreased gradually. The expression of defensin-5 mRNA in group T was significantly lower than that in group E (0.487 ± 0.149 vs 0.758 ± 0.160, P < 0.05) apparently in 24 h. The expression of defensin-5 mRNA at 2 h in group T was significantly higher than that in group C (0.824 ± 0.158 vs 0.631 ± 0.146, P < 0.05).

CONCLUSION

MPO and defensin-5 mRNA increase in preweaning rats with LPS-induced intestinal injury. Bifidobacterium protects the gut by inhibiting MPO activity, not by increasing defensin-5 secretion.

摘要

目的

探讨双歧杆菌对内毒素诱导的断奶前大鼠肠道损伤的保护作用。

方法

将断奶前大鼠随机分为三组（每组n = 40）：对照组（C组）、模型组（E组）和治疗组（T组）。E组和T组均腹腔注射剂量为5 mg/kg（溶于生理盐水中浓度为5 mg/L）的脂多糖（LPS），T组在给予LPS前7天灌胃双歧杆菌悬液（2.0×10⁹CFU/mL，每次0.5 mL，每日两次，直至实验结束）。C组腹腔注射生理盐水。腹腔注射和灌胃后，将大鼠放回初始笼中进行母乳喂养。在内毒素或生理盐水注射后分别于2、6、12、24或72小时处死大鼠，收集血清和回肠组织样本。在不同时间检测血清和回肠中髓过氧化物酶（MPO）含量，采用逆转录-聚合酶链反应评估回肠防御素-5 mRNA的表达。

结果

E组血清和回肠MPO含量显著高于C组（血清含量：107.50±17.70 vs 157.14±24.67，P < 0.05；回肠含量：1.03±0.21 vs 1.57±0.33，P < 0.05），分别在12小时和6小时达到峰值。T组MPO含量显著低于E组（血清含量：114.38±24.56 vs 145.25±23.62，P < 0.05；回肠含量：1.25±0.24 vs 1.57±0.33，P < 0.05）。E组防御素-5 mRNA表达显著高于C组（0.953±0.238 vs 0.631±0.146，P < 0.05），在2小时达到峰值，然后逐渐下降。T组防御素-5 mRNA表达在24小时时显著低于E组（0.487±0.149 vs 0.758±0.160，P < 0.05）。T组2小时时防御素-5 mRNA表达显著高于C组（0.824±0.158 vs 0.631±0.146，P < 0.05）。