Inhibition of heat shock protein 90 alleviates steatosis and macrophage activation in murine alcoholic liver injury
Department of Medicine, Division of Gastroenterology; Proteomics and Mass Spectrometry Facility
Biochemistry | Digestive System Diseases | Hepatology | Pharmacology | Therapeutics
BACKGROUND and AIMS: Heat shock protein 90 (hsp90) is an emerging therapeutic target in chronic liver diseases. Hsp90 plays an important role in liver immune cell activation; however its role in alcoholic liver disease (ALD) remains elusive. Here we hypothesize that hsp90 is crucial in alcohol induced steatosis and pro-inflammatory cytokine production. To test this hypothesis, we employed a pharmacological inhibitor of hsp90, 17-DMAG (17-Dimethylamino-ethylamino-17-demethoxygeldanamycin) in an in vivo mouse model of acute and chronic alcoholic liver injury.
METHODS: C57BL/6 mice were given either a single dose of ethanol via oral gavage (acute) or chronically fed alcohol for 2 weeks followed by oral gavage (chronic-binge). 17-DMAG was administered during or at the end of feeding. Liver injury parameters, inflammatory cytokines and lipid metabolism genes were analysed.
RESULTS: Our results reveal increased expression of hsp90 in human and mouse alcoholic livers. In vivo inhibition of hsp90, using 17-DMAG, not only prevented but also alleviated alcoholic liver injury, determined by lower serum ALT, AST and reduced hepatic triglycerides. Mechanistic analysis showed that 17-DMAG decreased alcohol mediated oxidative stress, reduced serum endotoxin, decreased inflammatory cells, and diminished sensitization of liver macrophages to LPS, resulting in downregulation of CD14, NFkappaB inhibition, and decreased pro-inflammatory cytokine production. Hsp90 inhibition decreased fatty acid synthesis genes via reduced nuclear SREBP-1 and favoured fatty acid oxidation genes via PPARalpha.
CONCLUSIONS: Inhibition of hsp90 decreased alcohol induced steatosis and pro-inflammatory cytokines and inhibited alcoholic liver injury. Hsp90 is therefore relevant in human alcoholic cirrhosis and a promising therapeutic target in ALD. Elsevier B.V. All rights reserved.
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Citation: J Hepatol. 2014 Oct;61(4):903-11. doi: 10.1016/j.jhep.2014.05.024. Epub 2014 May 22. Link to article on publisher's site
Journal of hepatology
Ambade, Aditya; Catalano, Donna; Lim, Arlene; Kopoyan, Andre; Shaffer, Scott A.; and Mandrekar, Pranoti, "Inhibition of heat shock protein 90 alleviates steatosis and macrophage activation in murine alcoholic liver injury" (2014). University of Massachusetts Medical School Faculty Publications. 555.