Role of snail activation in alcohol-induced iNOS-mediated disruption of intestinal epithelial cell permeability.
Role of snail activation in alcohol-induced iNOS-mediated disruption of intestinal epithelial cell permeability.
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DOI：
10.1111/j.1530-0277.2011.01510.x
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发表时间：
2011-09
期刊：
影响因子：
--
通讯作者：
Keshavarzian A
中科院分区：
文献类型：
--
作者：
Forsyth CB;Tang Y;Shaikh M;Zhang L;Keshavarzian A
慢性酒精使用导致许多病理影响，包括酒精性肝病（ALD）。ALD发病机制需要内毒素血症。我们以前的研究表明，增加肠道通透性是内毒素血症的主要原因，这种肠道渗漏依赖于酒精刺激酒精受试者和酒精性脂肪性肝炎（ASH）的啮齿动物模型中的诱导型一氧化氮合酶（iNOS）。酒精诱导的、iNOS介导的肠道屏障功能破坏的机制尚不清楚。我们最近发现酒精刺激转录因子Snail和上皮间质转化生物标志物的激活。由于激活的Snail破坏了紧密连接蛋白，我们假设iNOS激活Snail可能是介导酒精刺激的肠上皮细胞通透性过高的关键信号通路之一。我们测量了酒精喂养的C57 BL/6对照和iNOS KO小鼠的肠道通透性，并测量了这些小鼠肠道中Snail蛋白的表达。然后，我们使用肠屏障± Snail的siRNA抑制的Caco-2细胞模型检查肠上皮通透性。我们评估了Caco-2细胞中酒精对Snail的激活± L-NIL或siRNA对iNOS的抑制。最后，我们评估了酒精± siRNA抑制p21激活激酶（PAK 1）的Snail激活。我们的数据表明，慢性酒精喂养促进野生型BL/6，但不是在iNOS KO小鼠肠通透性过高。Snail蛋白表达在酒精处理的野生型小鼠的肠道中增加，但在iNOS KO小鼠中没有。Snail的SiRNA抑制显著抑制Caco-2细胞单层中酒精诱导的高通透性。SnailpS 246激活的酒精刺激通过用L-NIL或用siRNA抑制iNOS来阻断。PAK 1的SiRNA抑制显著抑制Caco-2细胞中酒精介导的Snail活化。我们的数据证实了我们以前的结果，并进一步证明，酒精诱导的啮齿动物和肠上皮细胞单层的肠道渗漏是iNOS依赖。我们的数据还支持Snail激活在酒精诱导的iNOS介导的肠通透性过高中的新作用，PAK 1负责酒精刺激下Ser 246处的Snail激活。对酒精诱导的肠通透性过高的这些机制的鉴定可以为预防和治疗酒精诱导的肠漏、内毒素血症和酒精中毒的内毒素相关并发症（例如ALD）提供新的治疗靶点。
Chronic alcohol use results in many pathological effects including alcoholic liver disease (ALD). ALD pathogenesis requires endotoxemia. Our previous studies showed that increased intestinal permeability is the major cause of endotoxemia and that this gut leakiness is dependent on alcohol stimulation of inducible nitric oxide synthase (iNOS) in both alcoholic subjects and rodent models of alcoholic steatohepatitis (ASH). The mechanism of the alcohol-induced, iNOS-mediated disruption of the intestinal barrier function is not known. We have recently shown that alcohol stimulates activation of the transcription factor Snail and biomarkers of epithelial mesenchymal transition. Since activated Snail disrupts tight junctional proteins , we hypothesized that activation of Snail by iNOS might be one of the key signaling pathways mediating alcohol stimulated intestinal epithelial cell hyperpermeability. We measured intestinal permeability in alcohol-fed C57BL/6 control and iNOS KO mice and measured Snail protein expression in the intestines of these mice. We then examined intestinal epithelial permeability using the Caco-2 cell model of the intestinal barrier ± siRNA inhibition of Snail. We assessed Snail activation by alcohol in Caco-2 cells ± inhibition of iNOS with L-NIL or siRNA. Finally, we assessed Snail activation by alcohol ± inhibition with siRNA for p21-activated kinase (PAK1). Our data show that chronic alcohol feeding promotes intestinal hyperpermeability in wild type BL/6 but not in iNOS KO mice. Snail protein expression was increased in the intestines of alcohol-treated wild type mice but not in iNOS KO mice. SiRNA inhibition of Snail significantly inhibited alcohol-induced hyperpermeability in Caco-2 cell monolayers. Alcohol stimulation of SnailpS246 activation was blocked by inhibition of iNOS with L-NIL or with siRNA. SiRNA inhibition of PAK1 significantly inhibited alcohol-mediated activation of Snail in Caco-2 cells. Our data confirmed our prior results and further demonstrated that alcohol-induced gut leakiness in rodents and intestinal epithelial cell monolayers is iNOS dependent. Our data also support a novel role for Snail activation in alcohol-induced, iNOS mediated intestinal hyperpermeability and that PAK1 is responsible for activation of Snail at Ser246 with alcohol stimulation. Identification of these mechanisms for alcohol-induced intestinal hyperpermeability may provide new therapeutic targets for prevention and treatment of alcohol-induced leaky gut, endotoxemia and endotoxin- associated complications of alcoholism such as ALD.
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影响因子：
64.8
作者：
Martin, Adam C.;Kaschube, Matthias;Wieschaus, Eric F.
通讯作者：
Wieschaus, Eric F.
影响因子：
4.8
作者：
Hou, YL;Ye, RD;Browning, DD
通讯作者：
Browning, DD
影响因子：
1.7
作者：
Blanco, AM;Pascual, M;Guerri, C
通讯作者：
Guerri, C
影响因子：
21.3
作者：
Batlle, E;Sancho, E;de Herreros, AG
通讯作者：
de Herreros, AG
DOI：
10.1124/jpet.102.047852
发表时间：
2003-06-01
影响因子：
3.5
作者：
Lambert, JC;Zhou, ZX;Kang, YJ
通讯作者：
Kang, YJ