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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

Proliferation of HSCs was reduced by deficiency of NOX1 and NOX4 in response to liver injury and PDGF.(A) HSC proliferation is reduced in NOX1KO and NOX4KO mice after CCl4 injury. HSC proliferation in liver was presented by PCNA immunofluorescence microscopy. Desmin is a specific marker of HSCs (Red). PCNA is a marker of proliferation (Green). Original magnification X10. (B) Proliferation was reduced in HSCs lacking NOX1 and NOX4 in response to PDGF (10 ng/ml) for 24 h. Proliferative HSCs were presented by Ki67 (Red) immunofluorescence microscopy. Nuclei were presented by DAPI (Blue). Original magnification X10. (C) Graph of PCNA-positive HSCs in vivo. (D) Graph of Ki67-positive HSCs in vitro.
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pone.0129743.g006: Proliferation of HSCs was reduced by deficiency of NOX1 and NOX4 in response to liver injury and PDGF.(A) HSC proliferation is reduced in NOX1KO and NOX4KO mice after CCl4 injury. HSC proliferation in liver was presented by PCNA immunofluorescence microscopy. Desmin is a specific marker of HSCs (Red). PCNA is a marker of proliferation (Green). Original magnification X10. (B) Proliferation was reduced in HSCs lacking NOX1 and NOX4 in response to PDGF (10 ng/ml) for 24 h. Proliferative HSCs were presented by Ki67 (Red) immunofluorescence microscopy. Nuclei were presented by DAPI (Blue). Original magnification X10. (C) Graph of PCNA-positive HSCs in vivo. (D) Graph of Ki67-positive HSCs in vitro.

Mentions: We performed double immunofluorescence staining of desmin and PCNA to determine the effects of NOX1 and NOX4 on HSC proliferation in the livers of WT, NOX1KO and NOX4KO mice after CCl4 injury. Proliferating HSCs (desmin+PCNA+ cells) were increased in WT mice. However, there were fewer proliferated HSCs in NOX1KO and NOX4KO mice (Fig 6A and 6C).


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)

Proliferation of HSCs was reduced by deficiency of NOX1 and NOX4 in response to liver injury and PDGF.(A) HSC proliferation is reduced in NOX1KO and NOX4KO mice after CCl4 injury. HSC proliferation in liver was presented by PCNA immunofluorescence microscopy. Desmin is a specific marker of HSCs (Red). PCNA is a marker of proliferation (Green). Original magnification X10. (B) Proliferation was reduced in HSCs lacking NOX1 and NOX4 in response to PDGF (10 ng/ml) for 24 h. Proliferative HSCs were presented by Ki67 (Red) immunofluorescence microscopy. Nuclei were presented by DAPI (Blue). Original magnification X10. (C) Graph of PCNA-positive HSCs in vivo. (D) Graph of Ki67-positive HSCs in vitro.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0129743.g006: Proliferation of HSCs was reduced by deficiency of NOX1 and NOX4 in response to liver injury and PDGF.(A) HSC proliferation is reduced in NOX1KO and NOX4KO mice after CCl4 injury. HSC proliferation in liver was presented by PCNA immunofluorescence microscopy. Desmin is a specific marker of HSCs (Red). PCNA is a marker of proliferation (Green). Original magnification X10. (B) Proliferation was reduced in HSCs lacking NOX1 and NOX4 in response to PDGF (10 ng/ml) for 24 h. Proliferative HSCs were presented by Ki67 (Red) immunofluorescence microscopy. Nuclei were presented by DAPI (Blue). Original magnification X10. (C) Graph of PCNA-positive HSCs in vivo. (D) Graph of Ki67-positive HSCs in vitro.
Mentions: We performed double immunofluorescence staining of desmin and PCNA to determine the effects of NOX1 and NOX4 on HSC proliferation in the livers of WT, NOX1KO and NOX4KO mice after CCl4 injury. Proliferating HSCs (desmin+PCNA+ cells) were increased in WT mice. However, there were fewer proliferated HSCs in NOX1KO and NOX4KO mice (Fig 6A and 6C).

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