Spatz, Madeleine, Ciocan, Dragos, Merlen, Gregory, Rainteau, Dominique, Humbert, Lydie, Gomes-Rochette, Neuza, Hugot, Cindy, Trainel, Nicolas, Mercier-Nomé, Françoise, Domenichini, Séverine, Puchois, Virginie, Wrzosek, Laura, Ferrere, Gladys, Tordjmann, Thierry, Perlemuter, Gabriel, Cassard, Anne-Marie, Inflammation, microbiome, immunosurveillance (MI2), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Saclay, AP-HP - Hôpital Antoine Béclère [Clamart], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Physiopathologie et traitement des maladies du foie, Hôpital Paul Brousse-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Saclay, Laboratoire des biomolécules (LBM UMR 7203), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Chimie Moléculaire de Paris Centre (FR 2769), Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Plateforme de métabolomique, Direction de la recherche [Gustave Roussy], Institut Gustave Roussy (IGR)-Institut Gustave Roussy (IGR), CHU Saint-Antoine [AP-HP], and Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)
Background & Aims Bile-acid metabolism and the intestinal microbiota are impaired in alcohol-related liver disease. Activation of the bile-acid receptor TGR5 (or GPBAR1) controls both biliary homeostasis and inflammatory processes. We examined the role of TGR5 in alcohol-induced liver injury in mice. Methods We used TGR5-deficient (TGR5-KO) and wild-type (WT) female mice, fed alcohol or not, to study the involvement of liver macrophages, the intestinal microbiota (16S sequencing), and bile-acid profiles (high-performance liquid chromatography coupled to tandem mass spectrometry). Hepatic triglyceride accumulation and inflammatory processes were assessed in parallel. Results TGR5 deficiency worsened liver injury, as shown by greater steatosis and inflammation than in WT mice. Isolation of liver macrophages from WT and TGR5-KO alcohol-fed mice showed that TGR5 deficiency did not increase the pro-inflammatory phenotype of liver macrophages but increased their recruitment to the liver. TGR5 deficiency induced dysbiosis, independently of alcohol intake, and transplantation of the TGR5-KO intestinal microbiota to WT mice was sufficient to worsen alcohol-induced liver inflammation. Secondary bile-acid levels were markedly lower in alcohol-fed TGR5-KO than normally fed WT and TGR5-KO mice. Consistent with these results, predictive analysis showed the abundance of bacterial genes involved in bile-acid transformation to be lower in alcohol-fed TGR5-KO than WT mice. This altered bile-acid profile may explain, in particular, why bile-acid synthesis was not repressed and inflammatory processes were exacerbated. Conclusions A lack of TGR5 was associated with worsening of alcohol-induced liver injury, a phenotype mainly related to intestinal microbiota dysbiosis and an altered bile-acid profile, following the consumption of alcohol. Lay summary Excessive chronic alcohol intake can induce liver disease. Bile acids are molecules produced by the liver and can modulate disease severity. We addressed the specific role of TGR5, a bile-acid receptor. We found that TGR5 deficiency worsened alcohol-induced liver injury and induced both intestinal microbiota dysbiosis and bile-acid pool remodelling. Our data suggest that both the intestinal microbiota and TGR5 may be targeted in the context of human alcohol-induced liver injury., Graphical abstract, Highlights • TGR5 deficiency (TGR5-KO) worsened alcohol-induced liver injury in mice. • This is linked to bile acid and intestinal microbiota changes. • Bacterial genes involved in bile-acid transformation are decreased in TGR5-KO mice. • Liver macrophage content increases without worsening of the inflammatory phenotype. • Transferring TGR5-KO microbiota in wild-type mice exacerbates liver inflammation.