摘要
目的 探究褪黑素(Mel)是否能够通过调控蛋白激酶B(Akt)/哺乳动物雷帕霉素靶蛋白(mTOR)通路对坏死性小肠结肠炎(NEC)新生大鼠肠道屏障功能发挥保护作用。方法 90只新生大鼠随机分为正常组、模型组、Mel低(15mg/kg)、高剂量组(30mg/kg)与Mel(30mg/kg)+Akti(5μmol/L)组,除正常组外,其余4组建立NEC模型。实验结束后,取眼静脉血分离血清,检测D-乳酸、二胺氧化酶(DAO)和内毒素含量;取回盲部肠组织,用于HE染色及检测IL-6、IL-1β、TNF-α含量与自噬基因(Beclin-1)、LC3B、p-Akt/Akt、p-mTOR/mTOR表达水平。结果 与正常组比较,模型组大鼠回盲部肠组织细胞出现变性坏死,黏膜肌层水肿,绒毛脱落、缺失等现象;血清中D-乳酸、DAO、内毒素含量与肠组织中IL-6、IL-1β、TNF-α含量和Beclin-1、LC3B蛋白阳性率均明显升高(P<0.05),p-Akt/Akt、p-mTOR/mTOR明显降低(P<0.05);与模型组比较,Mel低、高剂量组大鼠回盲部肠组织病变明显改善;D-乳酸、DAO、内毒素含量与IL-6、IL-1β、TNF-α含量和Beclin-1、LC3B蛋白阳性率均依次降低(P<0.05),p-Akt/Akt、p-mTOR/mTOR升高(P<0.05);与Mel高剂量组比较,Mel+Akti组大鼠回盲部肠组织病变加重;D-乳酸、DAO、内毒素含量与肠组织中IL-6、IL-1β、TNF-α含量和Beclin-1、LC3B蛋白阳性率均明显升高(P<0.05),p-Akt/Akt、p-mTOR/mTOR明显降低(P<0.05)。结论 Mel能够通过上调Akt/mTOR信号通路蛋白表达,抑制自噬,对NEC新生大鼠肠道屏障功能发挥保护作用。
Objective To explore whether melatonin(Mel) can protect the intestinal barrier function of neonatal rats with necrotizing enterocolitis(NEC) by regulating the Akt/mTOR pathway. Methods Ninety newborn rats were randomly divided into normal group, model group, low(15 mg/kg) and high(30 mg/kg) dose Mel groups, and Mel(30 mg/kg) + Akti(Akt inhibitor, 5 μmol/L) group. Except for the normal group, NEC models were established in rats of the other 4 groups. After the experiment, the ocular venous blood was collected to detect the contents of serum D-lactic acid, diamine oxidase(DAO) and endotoxin. The ileocecum was retrieved for HE staining and detection of IL-6, IL-1β, TNF-α contents and autophagy gene(Beclin-1), LC3 B, p-Akt/Akt, p-mTOR/mTOR expression levels. Results Compared with the normal group, the cells in ileocecum of the model group obviously showed degeneration and necrosis, mucosal muscular layer edema and loss of villi. Serum D-lactic acid, DAO, endotoxin content and intestinal tissue IL-6, IL-1β, TNF-α contents and Beclin-1, LC3 B protein positive rates significantly increased(P<0.05), p-Akt/Akt and p-mTOR/mTOR levels were significantly reduced(P<0.05). Compared with the model group, the pathological changes of the ileocecal intestine tissue of the rats in the low and high dose Mel groups were significantly improved. Serum D-lactic acid, DAO, endotoxin content and IL-6, IL-1β, TNF-α contents and the positive rates of Beclin-1 and LC3 B protein were reduced in sequence(P<0.05), p-Akt/Akt and p-mTOR/mTOR were increased(P<0.05). Compared with the Mel high-dose group, the ileocecal intestinal tissue lesions in the Mel+Akti group were worse. Serum D-lactic acid, DAO, endotoxin content and IL-6, IL-1β, TNF-α contents in intestinal tissue and the positive rates of Beclin-1, LC3 B protein were significantly increased(P<0.05), p-Akt/Akt and p-mTOR/mTOR were significantly reduced(P<0.05). Conclusions Mel can up-regulate the expression of Akt/mTOR signaling pathway protein to inhibit autophagy and protect the
作者
周丽霞
蔡冬
陈有平
ZHOU Li-xia;CAI Dong;CHEN You-ping(Division of Neonatology,Hainan General Hospital,Haikou,Hainan 570100,China)
出处
《中国儿童保健杂志》
CAS
CSCD
2022年第6期622-626,636,共6页
Chinese Journal of Child Health Care
基金
2016年度海南省卫生计生行业科研项目(15A200076)。
