245 - Liver Specific Deletion of Microrna-34A Alleviates Cellular Senescence and Liver Fibrosis During Experimental Cholestasis

Background: Treatment with the chemotherapy drug doxorubicin (DOX) may lead to toxicities that affect non-cancer cells including the liver. Supplementing the diet with creatine (Cr) has been suggested as a potential intervention to minimize DOX-induced side effects, but its effect in alleviating DOX-induced hepatoxicity is currently unknown. Therefore, we aimed to examine the effects of Cr supplementation on DOX-induced liver damage. Methods: Male Sprague-Dawley rats were fed a diet supplemented with 2% Cr for four weeks, 4% Cr for one week followed by 2% Cr for three more weeks, or control diet for four weeks. Animals then received either a bolus i.p. injection of DOX (15 mg/kg) or saline as a placebo. Animals were then sacrificed five days-post injection and markers of hepatoxicity were analyzed using the liver-to-body weight ratio, aspartate transaminase (AST)-to- alanine aminotransferase (ALT) ratio, alkaline phosphatase (ALP), lipemia, and T-Bilirubin. In addition, hematoxylin and eosin (H&E) staining, Picro-Sirius Red staining, and immunofluorescence staining for CD45, 8-OHdG, and β-galactosidase were performed to evaluate liver morphology, fibrosis, inflammation, oxidative stress, and cellular senescence, respectively. The mRNA levels for biomarkers of liver fibrosis, inflammation, oxidative stress, and senescence-related genes were measured in liver tissues. Chromosomal stability was evaluated using global DNA methylation ELISA. Results: The ALT/AST ratio and liver to body weight ratio tended to increase in the DOX group, and Cr supplementation tended to attenuate this increase. Furthermore, elevated levels of liver fibrosis, inflammation, oxidative stress, and senescence were observed with DOX treatment, and Cr supplementation prior to DOX treatment ameliorated this hepatoxicity. Moreover, DOX treatment resulted in chromosomal instability (i.e., altered DNA methylation profile), and Cr supplementation showed a tendency to restore chromosomal stability with DOX treatment. Conclusion: The data suggest that Cr protected against DOX-induced hepatotoxicity by attenuating fibrosis, inflammation, oxidative stress, and senescence.

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Polyphenols from Camellia sinenesis attenuate experimental cholestasis-induced liver fibrosis in rats

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00008.2003 ◽

2003 ◽

Vol 285 (5) ◽

pp. G1004-G1013 ◽

Cited By ~ 59

Author(s):

Zhi Zhong ◽

Matthias Froh ◽

Mark Lehnert ◽

Robert Schoonhoven ◽

Liu Yang ◽

...

Keyword(s):

Bile Duct ◽

Liver Fibrosis ◽

Transforming Growth Factor ◽

Bile Duct Ligation ◽

Smooth Muscle Actin ◽

Control Diet ◽

Free Radical Scavengers ◽

Bile Duct Proliferation ◽

Duct Ligation ◽

Experimental Cholestasis

Accumulation of hydrophobic bile acids during cholestasis leads to generation of oxygen free radicals in the liver. Accordingly, this study investigated whether polyphenols from green tea Camellia sinenesis, which are potent free radical scavengers, decrease hepatic injury caused by experimental cholestasis. Rats were fed a standard chow or a diet containing 0.1% polyphenolic extracts from C. sinenesis starting 3 days before bile duct ligation. After bile duct ligation, serum alanine transaminase increased to 760 U/l after 1 day in rats fed a control diet. Focal necrosis and bile duct proliferation were also observed after 1–2 days, and fibrosis developed 2–3 wk after bile duct ligation. Additionally, procollagen-α1(I) mRNA increased 30-fold 3 wk after bile duct ligation, accompanied by increased expression of α-smooth muscle actin and transforming growth factor-β and the accumulation of 4-hydroxynenonal, an end product of lipid peroxidation. Polyphenol feeding blocked or blunted all of these bile duct ligation-dependent changes by 45–73%. Together, the results indicate that cholestasis due to bile duct ligation causes liver injury by mechanisms involving oxidative stress. Polyphenols from C. sinenesis scavenge oxygen radicals and prevent activation of stellate cells, thereby minimizing liver fibrosis.

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Viral gene delivery of superoxide dismutase attenuates experimental cholestasis-induced liver fibrosis in the rat

Gene Therapy ◽

10.1038/sj.gt.3301638 ◽

2002 ◽

Vol 9 (3) ◽

pp. 183-191 ◽

Cited By ~ 40

Author(s):

Z Zhong ◽

M Froh ◽

MD Wheeler ◽

O Smutney ◽

TG Lehmann ◽

...

Keyword(s):

Superoxide Dismutase ◽

Liver Fibrosis ◽

Gene Delivery ◽

Viral Gene ◽

Viral Gene Delivery ◽

Experimental Cholestasis

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Hepatocyte-specific TAK1 deficiency drives RIPK1 kinase-dependent inflammation to promote liver fibrosis and hepatocellular carcinoma

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2005353117 ◽

2020 ◽

Vol 117 (25) ◽

pp. 14231-14242 ◽

Cited By ~ 1

Author(s):

Shuixia Tan ◽

Jing Zhao ◽

Ziyu Sun ◽

Shuangyi Cao ◽

Kongyan Niu ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Death ◽

Liver Fibrosis ◽

Therapeutic Strategy ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Genetic Inactivation ◽

Downstream Effectors ◽

Compensatory Proliferation ◽

Specific Deletion

Transforming growth factor β-activated kinase1 (TAK1) encoded by the gene MAP3K7 regulates multiple important downstream effectors involved in immune response, cell death, and carcinogenesis. Hepatocyte-specific deletion of TAK1 inTak1ΔHEPmice promotes liver fibrosis and hepatocellular carcinoma (HCC) formation. Here, we report that genetic inactivation of RIPK1 kinase using a kinase dead knockin D138N mutation inTak1ΔHEPmice inhibits the expression of liver tumor biomarkers, liver fibrosis, and HCC formation. Inhibition of RIPK1, however, has no or minimum effect on hepatocyte loss and compensatory proliferation, which are the recognized factors important for liver fibrosis and HCC development. Using single-cell RNA sequencing, we discovered that inhibition of RIPK1 strongly suppresses inflammation induced by hepatocyte-specific loss of TAK1. Activation of RIPK1 promotes the transcription of key proinflammatory cytokines, such as CCL2, and CCR2+macrophage infiltration. Our study demonstrates the role and mechanism of RIPK1 kinase in promoting inflammation, both cell-autonomously and cell-nonautonomously, in the development of liver fibrosis and HCC, independent of cell death, and compensatory proliferation. We suggest the possibility of inhibiting RIPK1 kinase as a therapeutic strategy for reducing liver fibrosis and HCC development by inhibiting inflammation.

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LPS signaling enhances hepatic fibrogenesis caused by experimental cholestasis in mice

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00405.2005 ◽

2006 ◽

Vol 290 (6) ◽

pp. G1318-G1328 ◽

Cited By ~ 83

Author(s):

Fuyumi Isayama ◽

Ian N. Hines ◽

Michael Kremer ◽

Richard J. Milton ◽

Christy L. Byrd ◽

...

Keyword(s):

Bile Duct ◽

Liver Fibrosis ◽

Liver Injury ◽

Hepatic Fibrosis ◽

Bile Duct Ligation ◽

Wild Type ◽

Hepatic Macrophages ◽

Duct Ligation ◽

Lps Signaling ◽

Experimental Cholestasis

Although it is clear that bile acid accumulation is the major initiator of fibrosis caused by cholestatic liver disease, endotoxemia is a common side effect. However, the depletion of hepatic macrophages with gadolinium chloride blunts hepatic fibrosis. Because endotoxin is a key activator of hepatic macrophages, this study was designed to test the hypothesis that LPS signaling through CD14 contributes to hepatic fibrosis caused by experimental cholestasis. Wild-type mice and CD14 knockout mice (CD14−/−) underwent sham operation or bile duct ligation and were killed 3 wk later. Measures of liver injury, such as focal necrosis, biliary cell proliferation, and inflammatory cell influx, were not significantly different among the strains 3 wk after bile duct ligation. Markers of liver fibrosis such as Sirius red staining, liver hydroxyproline, and α-smooth muscle actin expression were blunted in CD14−/− mice compared with wild-type mice after bile duct ligation. Despite no difference in lymphocyte infiltration, the macrophage/monocyte activation marker OX42 (CD11b) and the oxidative stress/lipid peroxidation marker 4-hydroxynonenal were significantly upregulated in wild-type mice after bile duct ligation but not in CD14−/− mice. Increased profibrogenic cytokine mRNA expression in the liver after bile duct ligation was significantly blunted in CD14−/− mice compared with the wild type. The hypothesis that LPS was involved in experimental cholestatic liver fibrosis was tested using mice deficient in LPS-binding protein (LBP−/−). LBP−/− mice had less liver injury and fibrosis (Siruis red staining and hydroxyproline content) compared with wild-type mice after bile duct ligation. In conclusion, these data demonstrate that endotoxin in a CD14-dependent manner exacerbates hepatic fibrogenesis and macrophage activation to produce oxidants and cytokines after bile duct ligation.

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