Loss of guanylyl cyclase C (GCC) signaling leads to dysfunctional intestinal barrier.
Loss of guanylyl cyclase C (GCC) signaling leads to dysfunctional intestinal barrier.
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DOI：
10.1371/journal.pone.0016139
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发表时间：
2011-01-31
期刊：
影响因子：
3.7
通讯作者：
Cohen MB
中科院分区：
文献类型：
--
作者：
Han X;Mann E;Gilbert S;Guan Y;Steinbrecher KA;Montrose MH;Cohen MB
通过尿观音（UGN）和观音激活介导的观酰基环化酶C （GCC）信号是肠液稳态、肠细胞增殖/凋亡和肿瘤发生的重要介质。作为其中一些作用的机制，我们假设GCC信号介导肠屏障功能的调节。在野生型（WT）和GCC缺陷型（GCC - / -）小鼠（有和没有脂多糖（LPS）刺激）以及UGN缺陷型（UGN - / -）小鼠中，评估肠段的细胞旁通透性。实时荧光定量PCR检测IFNγ和肌球蛋白轻链激酶（MLCK）水平。研究了肠上皮细胞（IECs）和肠黏膜中紧密连接蛋白（TJPs）的表达、肌球蛋白II调节轻链（MLC）的磷酸化和STAT1的激活。在不存在GCC RNA干扰（RNAi）和不存在GCC RNA干扰（RNAi）的情况下，测定了在Transwell过滤器上生长的Caco-2和HT-29 IEC单层膜的通透性。我们发现，与WT相比，GCC - / -和UGN - / -小鼠的肠通透性增加，同时iec中IFNγ水平、MLCK和STAT1激活增加。与WT小鼠相比，LPS刺激可促进GCC - / -小鼠IECs中IFNγ和STAT1的激活。GCC缺陷肠中Claudin-2和JAM-A表达降低；与WT相比，GCC - / -和UGN - / -小鼠IECs中磷酸化的MLC水平显著增加。在基础条件下，GCC敲除诱导MLC磷酸化，增加IEC单层膜的通透性，增强TNFα和ifn γ诱导的单层膜的高通透性。GCC信号通过调节MLCK的激活和TJ的分解，对肠黏膜屏障的完整性起保护作用。因此，GCC信号激活可能代表了在损伤反应中维持小肠屏障的一种新机制。
Guanylyl Cyclase C (GCC) signaling via uroguanylin (UGN) and guanylin activation is a critical mediator of intestinal fluid homeostasis, intestinal cell proliferation/apoptosis, and tumorigenesis. As a mechanism for some of these effects, we hypothesized that GCC signaling mediates regulation of intestinal barrier function. Paracellular permeability of intestinal segments was assessed in wild type (WT) and GCC deficient (GCC−/−) mice with and without lipopolysaccharide (LPS) challenge, as well as in UGN deficient (UGN−/−) mice. IFNγ and myosin light chain kinase (MLCK) levels were determined by real time PCR. Expression of tight junction proteins (TJPs), phosphorylation of myosin II regulatory light chain (MLC), and STAT1 activation were examined in intestinal epithelial cells (IECs) and intestinal mucosa. The permeability of Caco-2 and HT-29 IEC monolayers, grown on Transwell filters was determined in the absence and presence of GCC RNA interference (RNAi). We found that intestinal permeability was increased in GCC−/− and UGN−/− mice compared to WT, accompanied by increased IFNγ levels, MLCK and STAT1 activation in IECs. LPS challenge promotes greater IFNγ and STAT1 activation in IECs of GCC−/− mice compared to WT mice. Claudin-2 and JAM-A expression were reduced in GCC deficient intestine; the level of phosphorylated MLC in IECs was significantly increased in GCC−/− and UGN−/− mice compared to WT. GCC knockdown induced MLC phosphorylation, increased permeability in IEC monolayers under basal conditions, and enhanced TNFα and IFNγ-induced monolayer hyperpermeability. GCC signaling plays a protective role in the integrity of the intestinal mucosal barrier by regulating MLCK activation and TJ disassembly. GCC signaling activation may therefore represent a novel mechanism in maintaining the small bowel barrier in response to injury.
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影响因子：
29.4
作者：
Han, XN;Sosnowska, D;Denson, LA
通讯作者：
Denson, LA
影响因子：
3.7
作者：
Hassan SW;Doody KM;Hardy S;Uetani N;Cournoyer D;Tremblay ML
通讯作者：
Tremblay ML
DOI：
10.1073/pnas.93.25.14827
发表时间：
1996-12-10
影响因子：
11.1
作者：
Carrithers, SL;Barber, MT;Waldman, SA
通讯作者：
Waldman, SA
影响因子：
5.3
作者：
Basu, Nirmalya;Bhandari, Rashna;Visweswariah, Sandhya S.
通讯作者：
Visweswariah, Sandhya S.
DOI：
10.1152/ajpgi.90595.2008
发表时间：
2009-07-01
影响因子：
4.5
作者：
Guan, Yanfang;Worrell, Roger T.;Montrose, Marshall H.
通讯作者：
Montrose, Marshall H.