Defects in cGMP-PKG pathway contribute to impaired NO-dependent responses in hepatic stellate cells upon activation
Defects in cGMP-PKG pathway contribute to impaired NO-dependent responses in hepatic stellate cells upon activation
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DOI：
10.1152/ajpgi.00297.2005
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发表时间：
2006-03-01
影响因子：
4.5
通讯作者：
Shah, VH
中科院分区：
文献类型：
--
作者：
Perri, RE;Langer, DA;Shah, VH
cGMP-PKG通路的缺陷导致肝星状细胞活化后NO依赖性反应受损。美国生理学杂志胃肠和肝脏生理学290：G535-G542，2006年。首次发表于2005年11月3日; doi：10.1152/ajpgi.00297.2005。尽管肝硬化中激活的肝星状细胞（HSC）对NO的反应受损，但NO可以拮抗肝星状细胞（HSC）的收缩。激活的HSC中NO反应的减少以及NO影响激活的HSC的机制仍不完全清楚。在正常大鼠HSC中，NO供体二乙胺NONOate（DEAN）显着增加cGMP的生产和减少血清诱导的收缩25%。鸟苷酸环化酶（sGC）抑制剂1H-[1，2，4]恶二唑并[4，3a]喹喔啉-1-酮（ODQ）消除了50%的DEAN效应，而cGMP类似物8-溴鸟苷3 '，5'-环一磷酸（8BrcGMP）重复了一半观察到的DEAN反应，表明cGMP依赖性蛋白激酶G（PKG）依赖性和非依赖性NO介导的正常HSC收缩拮抗机制。然而，NO供体并没有增加cGMP生产从体内激活的HSC从胆管结扎大鼠，并显示细胞内Ca 2+积累的改变，这表明有缺陷的cGMP依赖性效应途径。LX-2细胞系也证明缺乏响应于NO的cGMP产生，并且缺乏ODQ和8-BrcGMP在调节NO响应中的作用。然而，cGMP的独立作用，在响应NO保持在LX-2和相关的S-亚硝基化的蛋白质，效果重申在原发性HSC。基于腺病毒的PKG过表达显着减弱了8-BrcGMP引起的LX-2收缩25%。总之，这些研究表明NO通过cGMP依赖性和非依赖性途径影响HSC。HSC活化过程与维持cGMP非依赖性NO作用相关，但与cGMP-PKG依赖性NO信号传导缺陷相关，这在LX-2细胞中通过PKG基因递送得到改善。激活HSC中NO- cGMP下游的靶点可能是门静脉高压症治疗的新靶点。
Defects in cGMP-PKG pathway contribute to impaired NO-dependent responses in hepatic stellate cells upon activation. Am J Physiol Gastrointest Liver Physiol 290: G535-G542, 2006. First published November 3, 2005; doi: 10.1152/ajpgi.00297.2005.-NO antagonizes hepatic stellate cell (HSC) contraction, although activated HSC in cirrhosis demonstrate impaired responses to NO. Decreased NO responses in activated HSC and mechanisms by which NO affects activated HSC remain incompletely understood. In normal rat HSC, the NO donor diethylamine NONOate ( DEAN) significantly increased cGMP production and reduced serum-induced contraction by 25%. The guanylate cyclase (sGC) inhibitor 1H-[1,2,4] oxadiazolo-[4,3a] quinoxalin-1-one (ODQ) abolished 50% of DEAN effects, whereas the cGMP analog 8-bromoguanosine 3',5'-cyclic monophosphate (8BrcGMP) reiterated half the observed DEAN response, suggesting both cGMP-dependent protein kinase G(PKG)-dependent and -independent mechanisms of NO-mediated antagonism of normal HSC contraction. However, NO donors did not increase cGMP production from in vivo activated HSC from bile duct-ligated rats and showed alterations in intracellular Ca2+ accumulation suggesting defective cGMP-dependent effector pathways. The LX-2 cell line also demonstrated lack of cGMP generation in response to NO and a lack of effect of ODQ and 8-BrcGMP in modulating the NO response. However, cGMP-independent effects in response to NO were maintained in LX-2 and were associated with S-nitrosylation of proteins, an effect reiterated in primary HSC. Adenovirus-based overexpression of PKG significantly attenuated contraction of LX-2 by 25% in response to 8-BrcGMP. In summary, these studies demonstrate that NO affects HSC through cGMP-dependent and - independent pathways. The HSC activation process is associated with maintenance of cGMP-independent actions of NO but defects in cGMP-PKG-dependent NO signaling that are improved by PKG gene delivery in LX-2 cells. Activating targets downstream from NO- cGMP in activated HSC may represent a novel therapeutic target for portal hypertension.