Role of ghrelin hormone in the development of alcohol-associated liver disease - 27/04/24
Abstract |
Fatty liver is the earliest response of the liver to excessive alcohol consumption. Previously we identified that chronic alcohol administration increases levels of stomach-derived hormone, ghrelin, which by reducing circulating insulin levels, ultimately contributes to the development of alcohol-associated liver disease (ALD). In addition, ghrelin directly promotes fat accumulation in hepatocytes by enhancing de novo lipogenesis. Other than promoting ALD, ghrelin is known to increase alcohol craving and intake. In this study, we used a ghrelin receptor (GHSR) knockout (KO) rat model to characterize the specific contribution of ghrelin in the development of ALD with emphasis on energy homeostasis. Male Wistar wild type (WT) and GHSR-KO rats were pair-fed the Lieber-DeCarli control or ethanol diet for 6 weeks. At the end of the feeding period, glucose tolerance test was conducted, and tissue samples were collected. We observed reduced alcohol intake by GHSR-KOs compared to a previous study where WT rats were fed ethanol diet ad libitum. Further, when the WTs were pair-fed to GHSR-KOs, the KO rats exhibited resistance to develop ALD through improving insulin secretion/sensitivity to reduce adipose lipolysis and hepatic fatty acid uptake/synthesis and increase fatty acid oxidation. Furthermore, proteomic data revealed that ethanol-fed KO exhibit less alcohol-induced mitochondrial dysfunction and oxidative stress than WT rats. Proteomic data also confirmed that the ethanol-fed KOs are insulin sensitive and are resistant to hepatic steatosis development compared to WT rats. Together, these data confirm that inhibiting ghrelin action prevent alcohol-induced liver and adipose dysfunction independent of reducing alcohol intake.
Le texte complet de cet article est disponible en PDF.Graphical Abstract |
Role of ghrelin in the development of alcohol-associated fatty liver disease. Alcohol-induced increase in ghrelin levels inhibits insulin secretion. The consequent reduction in the circulating insulin levels promotes adipose lipolysis and mobilization of non-esterification fatty acids to the liver, ultimately contributing to the development of fatty liver. In addition, ghrelin directly promotes fat accumulation in hepatocytes by up regulating de novo lipogenesis. These detrimental effects are mediated via ghrelin's interaction with its receptor, growth hormone secretagogue receptor (GSHR) whose deletion prevented the development of alcohol-associated fatty liver disease (ALD) by increasing insulin secretion/sensitivity, preventing increased adipose lipolysis and hepatic de novo lipogenesis, and promoting hepatic fatty acid oxidation.
Role of ghrelin in the development of alcohol-associated fatty liver disease. Alcohol-induced increase in ghrelin levels inhibits insulin secretion. The consequent reduction in the circulating insulin levels promotes adipose lipolysis and mobilization of non-esterification fatty acids to the liver, ultimately contributing to the development of fatty liver. In addition, ghrelin directly promotes fat accumulation in hepatocytes by up regulating de novo lipogenesis. These detrimental effects are mediated via ghrelin's interaction with its receptor, growth hormone secretagogue receptor (GSHR) whose deletion prevented the development of alcohol-associated fatty liver disease (ALD) by increasing insulin secretion/sensitivity, preventing increased adipose lipolysis and hepatic de novo lipogenesis, and promoting hepatic fatty acid oxidation.Le texte complet de cet article est disponible en PDF.
Abbreviations : ACC, AKT, ALD, ALT, ATGL, AUC, AUD, CD 36, CGI-58, CPT1, DGAT1, FAS, G6PC, GHSR, GLP-1, GYS, HSL, IRS1, LEAP2, LIPA, NEFA, NRF2, OGTT, PCK1, PCK2, PLIN2, PNPLA7, PPARα, SREBP/SREBF, TG
Keywords : Chronic alcohol, Fatty liver disease, Organ crosstalk, Ghrelin, GHSR, Gut peptides
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Vol 174
Article 116595- mai 2024 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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