A Role for cAMP and Protein Kinase A in Experimental Necrotizing Enterocotitis
A Role for cAMP and Protein Kinase A in Experimental Necrotizing Enterocotitis
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DOI：
10.1016/j.ajpath.2016.10.014
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发表时间：
2017-02-01
影响因子：
6
通讯作者：
Hunter, Catherine J.
中科院分区：
文献类型：
--
作者：
Blackwood, Brian P.;Wood, Douglas R.;Hunter, Catherine J.
坏死性小肠结肠炎（NEC）是一种毁灭性的肠道疾病，与阪崎克罗诺杆菌有关，通常影响早产儿。尽管NEC已被积极研究，但对上皮损伤和肠屏障损伤的病理生理机制知之甚少。环腺苷单磷酸（cAMP）和蛋白激酶A （PKA）是细胞凋亡的重要介质和调节因子。为了验证坂崎草增加实验性NEC中cAMP和PKA激活从而增加上皮细胞凋亡的假设，我们在体外和体内研究了坂崎草对cAMP和PKA的影响。具体地说，用阪崎肠杆菌感染大鼠肠上皮细胞和人肠上皮细胞系，检测cAMP水平和PKA磷酸化水平。感染后显示cAMP增加，磷酸化PKA增加。同样，在NEC幼鼠模型中，肠道cAMP和PKA磷酸化增加。这些增加与肠上皮细胞凋亡增加有关。PKA抑制剂（KT5720）的添加显著改善了这些效果，并降低了实验性NEC的严重程度。研究结果与人体组织样本的结果进行了比较。总的来说，这些观察结果表明cAMP和PKA磷酸化与NEC细胞凋亡增加有关，抑制PKA活化可以防止细胞凋亡和实验性NEC。
Necrotizing enterocolitis (NEC) is a devastating intestinal disease that has been associated with Crono-bacter sakazakii and typically affects premature infants. Although NEC has been actively investigated, Little is known about the mechanisms underlying the pathophysiology of epithelial injury and intestinal barrier damage. Cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) are important mediators and regulators of apoptosis. To test the hypothesis that C. sakazakii increases cAMP and PKA activation in experimental NEC resulting in increased epithelial apoptosis, we investigated the effects of C. sakazakii on cAMP and PKA in vitro and in vivo. Specifically, rat intestinal epithelial cells and a human intestinal epithelial cell line were infected with C. sakazakii, and cAMP Levels and phosphorylation of PKA were measured. An increase in cAMP was demonstrated after infection, as well as an increase in phosphorylated PKA. Similarly, increased intestinal cAMP and PKA phosphorylation were demonstrated in a rat pup model of NEC. These increases were correlated with increased intestinal epithelial apoptosis. The additional of a PKA inhibitor (KT5720) significantly ameliorated these effects and decreased the severity of experimental NEC. Findings were compared with results from human tissue samples. Collectively, these observations indicate that cAMP and PKA phosphorylation are associated with increased apoptosis in NEC and that inhibition of PKA activation protects against apoptosis and experimental NEC.