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Deficiency of NOX1 or NOX4 Prevents Liver Inflammation and Fibrosis in Mice through Inhibition of Hepatic Stellate Cell Activation.

Lan T, Kisseleva T, Brenner DA - PLoS ONE (2015)

Bottom Line: Furthermore, the mRNAs of proliferative and pro-fibrotic genes were downregulated in NOX1 and NOX4 knock-out activated HSCs (cultured on plastic for 5 days).Finally, NOX1 and NOX4 protein levels were increased in human livers with cirrhosis compared with normal controls.Thus, NOX1 and NOX4 signaling mediates the pathogenesis of liver fibrosis, including the direct activation of HSC.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, University of California San Diego, La Jolla, California, United States of America; Vascular Biology Research Institute, Guangdong Pharmaceutical University, Guangzhou, China.

ABSTRACT
Reactive oxygen species (ROS) produced by nicotinamide adenine dinucleotide phosphate oxidase (NOX) play a key role in liver injury and fibrosis. Previous studies demonstrated that GKT137831, a dual NOX1/4 inhibitor, attenuated liver fibrosis in mice as well as pro-fibrotic genes in hepatic stellate cells (HSCs) as well as hepatocyte apoptosis. The effect of NOX1 and NOX4 deficiency in liver fibrosis is unclear, and has never been directly compared. HSCs are the primary myofibroblasts in the pathogenesis of liver fibrosis. Therefore, we aimed to determine the role of NOX1 and NOX4 in liver fibrosis, and investigated whether NOX1 and NOX4 signaling mediates liver fibrosis by regulating HSC activation. Mice were treated with carbon tetrachloride (CCl4) to induce liver fibrosis. Deficiency of either NOX1 or NOX4 attenuates liver injury, inflammation, and fibrosis after CCl4 compared to wild-type mice. NOX1 or NOX4 deficiency reduced lipid peroxidation and ROS production in mice with liver fibrosis. NOX1 and NOX4 deficiency are approximately equally effective in preventing liver injury in the mice. The NOX1/4 dual inhibitor GKT137831 suppressed ROS production as well as inflammatory and proliferative genes induced by lipopolysaccharide (LPS), platelet-derived growth factor (PDGF), or sonic hedgehog (Shh) in primary mouse HSCs. Furthermore, the mRNAs of proliferative and pro-fibrotic genes were downregulated in NOX1 and NOX4 knock-out activated HSCs (cultured on plastic for 5 days). Finally, NOX1 and NOX4 protein levels were increased in human livers with cirrhosis compared with normal controls. Thus, NOX1 and NOX4 signaling mediates the pathogenesis of liver fibrosis, including the direct activation of HSC.

No MeSH data available.


Related in: MedlinePlus

Liver injury and inflammation were attenuated in NOX1KO and NOX4KO mice after CCl4 injury.Livers were obtained from WT, NOX1KO, and NOX4KO mice by 12 intragastric administrations with CCl4 for 6 weeks, twice a week. (A) H&E staining of liver sections and F4/80 immunohistochemistry staining with (C) its quantification. Original magnification X10. (C) Hepatic mRNAs of inflammatory genes was measured in WT, NOX1KO and NOX4KO mice after CCl4 injury by way of quantitative real-time PCR. HPRT was used as an internal control. The data are shown as fold mRNA induction compared with control mice. *P <0.05, **P < 0.01.
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pone.0129743.g002: Liver injury and inflammation were attenuated in NOX1KO and NOX4KO mice after CCl4 injury.Livers were obtained from WT, NOX1KO, and NOX4KO mice by 12 intragastric administrations with CCl4 for 6 weeks, twice a week. (A) H&E staining of liver sections and F4/80 immunohistochemistry staining with (C) its quantification. Original magnification X10. (C) Hepatic mRNAs of inflammatory genes was measured in WT, NOX1KO and NOX4KO mice after CCl4 injury by way of quantitative real-time PCR. HPRT was used as an internal control. The data are shown as fold mRNA induction compared with control mice. *P <0.05, **P < 0.01.

Mentions: To investigation the roles of NOX1 and NOX4 in liver inflammation, hepatic macrophage infiltration and inflammatory genes were evaluated. After CCl4 treatment, HE staining showed that inflammatory cell infiltration was decreased in NOX1KO and NOX4KO mice versus WT mice (Fig 2A). The expression of F4/80, macrophage marker, was significantly decreased in NOX1KO and NOX4KO mice compared with WT mice, as determined by IHC and quantitative real-time PCR (Fig 2A and 2B). In addition, hepatic mRNA expression of proinflammatory cytokines (TNF-α, MCP-1, IL-1β and MIP-1) was increased in WT mice after CCl4 treatment, but the increase was blunted in NOX1KO and NOX4KO mice (Fig 2C). These results indicate that increased liver inflammation in CCl4-treated WT mice was blunted in NOX1KO and NOX4KO mice.


Deficiency of NOX1 or NOX4 Prevents Liver Inflammation and Fibrosis in Mice through Inhibition of Hepatic Stellate Cell Activation.

Lan T, Kisseleva T, Brenner DA - PLoS ONE (2015)

Liver injury and inflammation were attenuated in NOX1KO and NOX4KO mice after CCl4 injury.Livers were obtained from WT, NOX1KO, and NOX4KO mice by 12 intragastric administrations with CCl4 for 6 weeks, twice a week. (A) H&E staining of liver sections and F4/80 immunohistochemistry staining with (C) its quantification. Original magnification X10. (C) Hepatic mRNAs of inflammatory genes was measured in WT, NOX1KO and NOX4KO mice after CCl4 injury by way of quantitative real-time PCR. HPRT was used as an internal control. The data are shown as fold mRNA induction compared with control mice. *P <0.05, **P < 0.01.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4519306&req=5

pone.0129743.g002: Liver injury and inflammation were attenuated in NOX1KO and NOX4KO mice after CCl4 injury.Livers were obtained from WT, NOX1KO, and NOX4KO mice by 12 intragastric administrations with CCl4 for 6 weeks, twice a week. (A) H&E staining of liver sections and F4/80 immunohistochemistry staining with (C) its quantification. Original magnification X10. (C) Hepatic mRNAs of inflammatory genes was measured in WT, NOX1KO and NOX4KO mice after CCl4 injury by way of quantitative real-time PCR. HPRT was used as an internal control. The data are shown as fold mRNA induction compared with control mice. *P <0.05, **P < 0.01.
Mentions: To investigation the roles of NOX1 and NOX4 in liver inflammation, hepatic macrophage infiltration and inflammatory genes were evaluated. After CCl4 treatment, HE staining showed that inflammatory cell infiltration was decreased in NOX1KO and NOX4KO mice versus WT mice (Fig 2A). The expression of F4/80, macrophage marker, was significantly decreased in NOX1KO and NOX4KO mice compared with WT mice, as determined by IHC and quantitative real-time PCR (Fig 2A and 2B). In addition, hepatic mRNA expression of proinflammatory cytokines (TNF-α, MCP-1, IL-1β and MIP-1) was increased in WT mice after CCl4 treatment, but the increase was blunted in NOX1KO and NOX4KO mice (Fig 2C). These results indicate that increased liver inflammation in CCl4-treated WT mice was blunted in NOX1KO and NOX4KO mice.

Bottom Line: Furthermore, the mRNAs of proliferative and pro-fibrotic genes were downregulated in NOX1 and NOX4 knock-out activated HSCs (cultured on plastic for 5 days).Finally, NOX1 and NOX4 protein levels were increased in human livers with cirrhosis compared with normal controls.Thus, NOX1 and NOX4 signaling mediates the pathogenesis of liver fibrosis, including the direct activation of HSC.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, University of California San Diego, La Jolla, California, United States of America; Vascular Biology Research Institute, Guangdong Pharmaceutical University, Guangzhou, China.

ABSTRACT
Reactive oxygen species (ROS) produced by nicotinamide adenine dinucleotide phosphate oxidase (NOX) play a key role in liver injury and fibrosis. Previous studies demonstrated that GKT137831, a dual NOX1/4 inhibitor, attenuated liver fibrosis in mice as well as pro-fibrotic genes in hepatic stellate cells (HSCs) as well as hepatocyte apoptosis. The effect of NOX1 and NOX4 deficiency in liver fibrosis is unclear, and has never been directly compared. HSCs are the primary myofibroblasts in the pathogenesis of liver fibrosis. Therefore, we aimed to determine the role of NOX1 and NOX4 in liver fibrosis, and investigated whether NOX1 and NOX4 signaling mediates liver fibrosis by regulating HSC activation. Mice were treated with carbon tetrachloride (CCl4) to induce liver fibrosis. Deficiency of either NOX1 or NOX4 attenuates liver injury, inflammation, and fibrosis after CCl4 compared to wild-type mice. NOX1 or NOX4 deficiency reduced lipid peroxidation and ROS production in mice with liver fibrosis. NOX1 and NOX4 deficiency are approximately equally effective in preventing liver injury in the mice. The NOX1/4 dual inhibitor GKT137831 suppressed ROS production as well as inflammatory and proliferative genes induced by lipopolysaccharide (LPS), platelet-derived growth factor (PDGF), or sonic hedgehog (Shh) in primary mouse HSCs. Furthermore, the mRNAs of proliferative and pro-fibrotic genes were downregulated in NOX1 and NOX4 knock-out activated HSCs (cultured on plastic for 5 days). Finally, NOX1 and NOX4 protein levels were increased in human livers with cirrhosis compared with normal controls. Thus, NOX1 and NOX4 signaling mediates the pathogenesis of liver fibrosis, including the direct activation of HSC.

No MeSH data available.


Related in: MedlinePlus