Mechanisms of NAFLD development and therapeutic strategies

Estes, C., Razavi, H., Loomba, R., Younossi, Z. & Sanyal, A. J. Modeling the epidemic of nonalcoholic fatty liver disease demonstrates an exponential increase in burden of disease. Hepatology 67, 123–133 (2018).

Younossi, Z. M. et al. The economic and clinical burden of nonalcoholic fatty liver disease in the United States and Europe. Hepatology 64, 1577–1586 (2016).

Goldberg, D. et al. Changes in the Prevalence of hepatitis C virus infection, nonalcoholic steatohepatitis, and alcoholic liver disease among patients with cirrhosis or liver failure on the waitlist for liver transplantation. Gastroenterology 152, 1090–1099 (2017).

Wong, R. J. et al. Nonalcoholic steatohepatitis is the second leading etiology of liver disease among adults awaiting liver transplantation in the United States. Gastroenterology 148, 547–555 (2015).

Mittal, S. et al. Hepatocellular carcinoma in the absence of cirrhosis in united states veterans is associated with nonalcoholic fatty liver disease. Clin. Gastroenterol. Hepatol. 14, 124–131.e1 (2016).

Dyson, J. et al. Hepatocellular cancer: the impact of obesity, type 2 diabetes and a multidisciplinary team. J. Hepatol. 60, 110–117 (2014).

Piscaglia, F. et al. Clinical patterns of hepatocellular carcinoma in nonalcoholic fatty liver disease: a multicenter prospective study. Hepatology 63, 827–838 (2016).

Younossi, Z. M. et al. Global epidemiology of nonalcoholic fatty liver disease—meta-analytic assessment of prevalence, incidence, and outcomes. Hepatology 64, 73–84 (2016).

Loomba, R. & Sanyal, A. J. The global NAFLD epidemic. Nat. Rev. Gastroenterol. Hepatol. 10, 686–690 (2013).

Siddiqui, M. S. et al. Case definitions for inclusion and analysis of endpoints in clinical trials for NASH through the lens of regulatory science. Hepatology 67, 2001–2012 (2018).

Singh, S. et al. Fibrosis progression in nonalcoholic fatty liver vs nonalcoholic steatohepatitis: a systematic review and meta-analysis of paired-biopsy studies. Clin. Gastroenterol. Hepatol. 13, 643–654.e1–9 (2015).

Lindenmeyer, C. C. & McCullough, A. J. The natural history of nonalcoholic fatty liver disease—an evolving view. Clin. Liver Dis. 22, 11–21 (2018).

Rinella, M. E. & Sanyal, A. J. Management of NAFLD: a stage-based approach. Nat. Rev. Gastroenterol. Hepatol. 13, 196–205 (2016).

Caussy, C. et al. Nonalcoholic fatty liver disease with cirrhosis increases familial risk for advanced fibrosis. J. Clin. Invest. 127, 2697–2704 (2017).

Loomba, R. et al. Heritability of hepatic fibrosis and steatosis based on a prospective twin study. Gastroenterology 149, 1784–1793 (2015).

Pouladi, N., Bime, C., Garcia, J. G. N. & Lussier, Y. A. Complex genetics of pulmonary diseases: lessons from genome-wide association studies and next-generation sequencing. Transl. Res. 168, 22–39 (2016).

McPherson, S. et al. Evidence of NAFLD progression from steatosis to fibrosing-steatohepatitis using paired biopsies: implications for prognosis and clinical management. J. Hepatol. 62, 1148–1155 (2015).

Huang, P. L. A comprehensive definition for metabolic syndrome. Dis. Model. Mech. 2, 231–237 (2009).

Käräjämäki, A. J. et al. Non-alcoholic fatty liver disease with and without metabolic syndrome: different long-term outcomes. Metabolism 66, 55–63 (2017).

Allen, A. M. et al. Nonalcoholic fatty liver disease incidence and impact on metabolic burden and death: a 20 year-community study. Hepatology 67, 1726–1736 (2018).

Bazick, J. et al. Clinical model for NASH and advanced fibrosis in adult patients with diabetes and NAFLD: guidelines for referral in NAFLD. Diabetes Care 38, 1347–1355 (2015).

Portillo-Sanchez, P. et al. High prevalence of nonalcoholic fatty liver disease in patients with type 2 diabetes mellitus and normal plasma aminotransferase levels. J. Clin. Endocrinol. Metab. 100, 2231–2238 (2015).

Kwok, R. et al. Screening diabetic patients for non-alcoholic fatty liver disease with controlled attenuation parameter and liver stiffness measurements: a prospective cohort study. Gut 65, 1359–1368 (2016).

Anstee, Q. M., Targher, G. & Day, C. P. Progression of NAFLD to diabetes mellitus, cardiovascular disease or cirrhosis. Nat. Rev. Gastroenterol. Hepatol. 10, 330–344 (2013).

Choudhury, J. & Sanyal, A. J. Insulin resistance and the pathogenesis of nonalcoholic fatty liver disease. Clin. Liver Dis. 8, 575–594 (2004). ix.

Ballestri, S. et al. Nonalcoholic fatty liver disease is associated with an almost twofold increased risk of incident type 2 diabetes and metabolic syndrome. Evidence from a systematic review and meta-analysis. J. Gastroenterol. Hepatol. 31, 936–944 (2016).

Lorbeer, R. et al. Association between MRI-derived hepatic fat fraction and blood pressure in participants without history of cardiovascular disease. J. Hypertens. 35, 737–744 (2017).

VanWagner, L. B. et al. Association of nonalcoholic fatty liver disease with subclinical myocardial remodeling and dysfunction: a population-based study. Hepatology 62, 773–783 (2015).

Musso, G. et al. Association of non-alcoholic fatty liver disease with chronic kidney disease: a systematic review and meta-analysis. PLoS Med. 11, e1001680 (2014).

Valbusa, F. et al. Nonalcoholic fatty liver disease and increased risk of 1-year all-cause and cardiac hospital readmissions in elderly patients admitted for acute heart failure. PLoS One 12, e0173398 (2017).

Sorrentino, P. et al. Predicting fibrosis worsening in obese patients with NASH through parenchymal fibronectin, HOMA-IR, and hypertension. Am. J. Gastroenterol. 105, 336–344 (2010).

Pelusi, S. et al. Renin–angiotensin system inhibitors, type 2 diabetes and fibrosis progression: an observational study in patients with nonalcoholic fatty liver disease. PLoS One 11, e0163069 (2016).

Namisaki, T. et al. Beneficial effects of combined ursodeoxycholic acid and angiotensin-II type 1 receptor blocker on hepatic fibrogenesis in a rat model of nonalcoholic steatohepatitis. J. Gastroenterol. 51, 162–172 (2016).

Noguchi, R. et al. Selective aldosterone blocker ameliorates the progression of non-alcoholic steatohepatitis in rats. Int. J. Mol. Med. 26, 407–413 (2010).

Pais, R. et al. A systematic review of follow-up biopsies reveals disease progression in patients with non-alcoholic fatty liver. J. Hepatol. 59, 550–556 (2013).

Ekstedt, M. et al. Long-term follow-up of patients with NAFLD and elevated liver enzymes. Hepatology 44, 865–873 (2006).

Ekstedt, M. et al. Fibrosis stage is the strongest predictor for disease-specific mortality in NAFLD after up to 33 years of follow-up. Hepatology 61, 1547–1554 (2015).

Angulo, P. et al. Liver fibrosis, but no other histologic features, is associated with long-term outcomes of patients with nonalcoholic fatty liver disease. Gastroenterology 149, 389–397.10 (2015).

Hagström, H. et al. Fibrosis stage but not NASH predicts mortality and time to development of severe liver disease in biopsy-proven NAFLD. J. Hepatol. 67, 1265–1273 (2017).

Sookoian, S. & Pirola, C. J. Genetic predisposition in nonalcoholic fatty liver disease. Clin. Mol. Hepatol. 23, 1–12 (2017).

Anstee, Q. M., Daly, A. K. & Day, C. P. Genetic modifiers of non-alcoholic fatty liver disease progression. Biochim. Biophys. Acta 1812, 1557–1566 (2011).

Eslam, M., Valenti, L. & Romeo, S. Genetics and epigenetics of NAFLD and NASH: clinical impact. J. Hepatol. 68, 268–279 (2018).

Romeo, S. et al. Genetic variation in PNPLA3 confers susceptibility to nonalcoholic fatty liver disease. Nat. Genet. 40, 1461–1465 (2008).

Bruschi, F. V. et al. The PNPLA3 I148M variant modulates the fibrogenic phenotype of human hepatic stellate cells. Hepatology 65, 1875–1890 (2017).

BasuRay, S., Smagris, E., Cohen, J. C. & Hobbs, H. H. The PNPLA3 variant associated with fatty liver disease (I148M) accumulates on lipid droplets by evading ubiquitylation. Hepatology 66, 1111–1124 (2017).

Stender, S. et al. Adiposity amplifies the genetic risk of fatty liver disease conferred by multiple loci. Nat. Genet. 49, 842–847 (2017).

Abul-Husn, N. S. et al. A protein-truncating HSD17B13 variant and protection from chronic liver disease. N. Engl. J. Med. 378, 1096–1106 (2018).

Alonso, C. et al. Metabolomic identification of subtypes of nonalcoholic steatohepatitis. Gastroenterology 152, 1449–1461.e7 (2017).

Neuschwander-Tetri, B. A. Hepatic lipotoxicity and the pathogenesis of nonalcoholic steatohepatitis: the central role of nontriglyceride fatty acid metabolites. Hepatology 52, 774–788 (2010).

Cusi, K. Role of obesity and lipotoxicity in the development of nonalcoholic steatohepatitis: pathophysiology and clinical implications. Gastroenterology 142, 711–725.e6 (2012).

Boursier, J. et al. The severity of nonalcoholic fatty liver disease is associated with gut dysbiosis and shift in the metabolic function of the gut microbiota. Hepatology 63, 764–775 (2016).

Hirsova, P., Ibrahim, S. H., Gores, G. J. & Malhi, H. Lipotoxic lethal and sublethal stress signaling in hepatocytes: relevance to NASH pathogenesis. J. Lipid Res. 57, 1758–1770 (2016).

Mota, M., Banini, B. A., Cazanave, S. C. & Sanyal, A. J. Molecular mechanisms of lipotoxicity and glucotoxicity in nonalcoholic fatty liver disease. Metabolism 65, 1049–1061 (2016).

Neuschwander-Tetri, B. A. Non-alcoholic fatty liver disease. BMC Med. 15, 45 (2017).

Lomonaco, R. et al. Effect of adipose tissue insulin resistance on metabolic parameters and liver histology in obese patients with nonalcoholic fatty liver disease. Hepatology 55, 1389–1397 (2012).

Pal, M., Febbraio, M. A. & Lancaster, G. I. The roles of c-Jun NH2-terminal kinases (JNKs) in obesity and insulin resistance. J. Physiol. (Lond.) 594, 267–279 (2016).

Han, M. S. et al. JNK expression by macrophages promotes obesity-induced insulin resistance and inflammation. Science 339, 218–222 (2013).

Samuel, V. T. & Shulman, G. I. The pathogenesis of insulin resistance: integrating signaling pathways and substrate flux. J. Clin. Invest. 126, 12–22 (2016).

Magkos, F. et al. Effects of moderate and subsequent progressive weight loss on metabolic function and adipose tissue biology in humans with obesity. Cell Metab. 23, 591–601 (2016).

Gastaldelli, A. et al. Importance of changes in adipose tissue insulin resistance to histological response during thiazolidinedione treatment of patients with nonalcoholic steatohepatitis. Hepatology 50, 1087–1093 (2009).

Donnelly, K. L. et al. Sources of fatty acids stored in liver and secreted via lipoproteins in patients with nonalcoholic fatty liver disease. J. Clin. Invest. 115, 1343–1351 (2005).

Jang, C. et al. The small intestine converts dietary fructose into glucose and organic acids. Cell Metab. 27, 351–361.e3 (2018).

Truswell, A. S., Seach, J. M. & Thorburn, A. W. Incomplete absorption of pure fructose in healthy subjects and the facilitating effect of glucose. Am. J. Clin. Nutr. 48, 1424–1430 (1988).

Rao, S. S., Attaluri, A., Anderson, L. & Stumbo, P. Ability of the normal human small intestine to absorb fructose: evaluation by breath testing. Clin. Gastroenterol. Hepatol. 5, 959–963 (2007).

Abdelmalek, M. F. et al. Higher dietary fructose is associated with impaired hepatic adenosine triphosphate homeostasis in obese individuals with type 2 diabetes. Hepatology 56, 952–960 (2012).

Schwarz, J. M. et al. Effects of dietary fructose restriction on liver fat, de novo lipogenesis, and insulin kinetics in children with obesity. Gastroenterology 153, 743–752 (2017).

Softic, S., Cohen, D. E. & Kahn, C. R. Role of dietary fructose and hepatic de novo lipogenesis in fatty liver disease. Dig. Dis. Sci. 61, 1282–1293 (2016).

Wakil, S. J. & Abu-Elheiga, L. A. Fatty acid metabolism: target for metabolic syndrome. J. Lipid Res. 50 Suppl, S138–S143 (2009).

Benhamed, F. et al. The lipogenic transcription factor ChREBP dissociates hepatic steatosis from insulin resistance in mice and humans. J. Clin. Invest. 122, 2176–2194 (2012).

Sanyal, A. J. et al. Pioglitazone, vitamin E, or placebo for nonalcoholic steatohepatitis. N. Engl. J. Med. 362, 1675–1685 (2010).

Arab, J. P., Karpen, S. J., Dawson, P. A., Arrese, M. & Trauner, M. Bile acids and nonalcoholic fatty liver disease: molecular insights and therapeutic perspectives. Hepatology 65, 350–362 (2017).

van Nierop, F. S. et al. Clinical relevance of the bile acid receptor TGR5 in metabolism. Lancet Diabetes Endocrinol. 5, 224–233 (2017).

Kajimura, S., Spiegelman, B. M. & Seale, P. Brown and beige fat: physiological roles beyond heat generation. Cell Metab. 22, 546–559 (2015).

Sanyal, A. J. et al. Nonalcoholic steatohepatitis: association of insulin resistance and mitochondrial abnormalities. Gastroenterology 120, 1183–1192 (2001).

Pessayre, D. & Fromenty, B. NASH: a mitochondrial disease. J. Hepatol. 42, 928–940 (2005).

Bril, F. et al. Metabolic and histological implications of intrahepatic triglyceride content in nonalcoholic fatty liver disease. Hepatology 65, 1132–1144 (2017).

Yki-Järvinen, H. Non-alcoholic fatty liver disease as a cause and a consequence of metabolic syndrome. Lancet Diabetes Endocrinol. 2, 901–910 (2014).

Perry, R. J., Samuel, V. T., Petersen, K. F. & Shulman, G. I. The role of hepatic lipids in hepatic insulin resistance and type 2 diabetes. Nature 510, 84–91 (2014).

Luukkonen, P. K. et al. Hepatic ceramides dissociate steatosis and insulin resistance in patients with non-alcoholic fatty liver disease. J. Hepatol. 64, 1167–1175 (2016).

Mauer, A. S., Hirsova, P., Maiers, J. L., Shah, V. H. & Malhi, H. Inhibition of sphingosine 1-phosphate signaling ameliorates murine nonalcoholic steatohepatitis. Am. J. Physiol. Gastrointest. Liver Physiol. 312, G300–G313 (2017).

Han, M. S. et al. Lysophosphatidylcholine as a death effector in the lipoapoptosis of hepatocytes. J. Lipid Res. 49, 84–97 (2008).

Ioannou, G. N. The role of cholesterol in the pathogenesis of NASH. Trends Endocrinol. Metab. 27, 84–95 (2016).

Trevaskis, J. L. et al. Glucagon-like peptide-1 receptor agonism improves metabolic, biochemical, and histopathological indices of nonalcoholic steatohepatitis in mice. Am. J. Physiol. Gastrointest. Liver Physiol. 302, G762–G772 (2012).

Asgharpour, A. et al. A diet-induced animal model of non-alcoholic fatty liver disease and hepatocellular cancer. J. Hepatol. 65, 579–588 (2016).

Krishnan, A. et al. A longitudinal study of whole body, tissue, and cellular physiology in a mouse model of fibrosing NASH with high fidelity to the human condition. Am. J. Physiol. Gastrointest. Liver Physiol. 312, G666–G680 (2017).

Han, J. & Kaufman, R. J. The role of ER stress in lipid metabolism and lipotoxicity. J. Lipid Res. 57, 1329–1338 (2016).

Puri, P. et al. Activation and dysregulation of the unfolded protein response in nonalcoholic fatty liver disease. Gastroenterology 134, 568–576 (2008).

Szabo, G. & Petrasek, J. Inflammasome activation and function in liver disease. Nat. Rev. Gastroenterol. Hepatol. 12, 387–400 (2015).

Guy, C. D. et al. Hedgehog pathway activation parallels histologic severity of injury and fibrosis in human nonalcoholic fatty liver disease. Hepatology 55, 1711–1721 (2012).

Marra, F. & Bertolani, C. Adipokines in liver diseases. Hepatology 50, 957–969 (2009).

Lanaspa, M. A. et al. Uric acid induces hepatic steatosis by generation of mitochondrial oxidative stress: potential role in fructose-dependent and -independent fatty liver. J. Biol. Chem. 287, 40732–40744 (2012).

Sookoian, S. & Pirola, C. J. Obstructive sleep apnea is associated with fatty liver and abnormal liver enzymes: a meta-analysis. Obes. Surg. 23, 1815–1825 (2013).

Henao-Mejia, J. et al. Inflammasome-mediated dysbiosis regulates progression of NAFLD and obesity. Nature 482, 179–185 (2012).

Liu, R. et al. Gut microbiome and serum metabolome alterations in obesity and after weight-loss intervention. Nat. Med. 23, 859–868 (2017).

Horwath, J. A. et al. Obesity-induced hepatic steatosis is mediated by endoplasmic reticulum stress in the subfornical organ of the brain. JCI Insight 2, 90170 (2017).

Csak, T. et al. Fatty acid and endotoxin activate inflammasomes in mouse hepatocytes that release danger signals to stimulate immune cells. Hepatology 54, 133–144 (2011).

Stienstra, R. et al. Inflammasome is a central player in the induction of obesity and insulin resistance. Proc. Natl Acad. Sci. USA 108, 15324–15329 (2011).

Mridha, A. R. et al. NLRP3 inflammasome blockade reduces liver inflammation and fibrosis in experimental NASH in mice. J. Hepatol. 66, 1037–1046 (2017).

Loomba, R. et al. Association between diabetes, family history of diabetes, and risk of nonalcoholic steatohepatitis and fibrosis. Hepatology 56, 943–951 (2012).

Bugianesi, E., McCullough, A. J. & Marchesini, G. Insulin resistance: a metabolic pathway to chronic liver disease. Hepatology 42, 987–1000 (2005).

Sabio, G. et al. A stress signaling pathway in adipose tissue regulates hepatic insulin resistance. Science 322, 1539–1543 (2008).

Tilg, H. The role of cytokines in non-alcoholic fatty liver disease. Dig. Dis. 28, 179–185 (2010).

Ghorpade, D. S. et al. Hepatocyte-secreted DPP4 in obesity promotes adipose inflammation and insulin resistance. Nature 555, 673–677 (2018).

Betrapally, N. S., Gillevet, P. M. & Bajaj, J. S. Changes in the intestinal microbiome and alcoholic and nonalcoholic liver diseases: causes or effects? Gastroenterology 150, 1745–1755.e3 (2016).

Loomba, R. et al. Gut microbiome-based metagenomic signature for non-invasive detection of advanced fibrosis in human nonalcoholic fatty liver disease. Cell Metab. 25, 1054–1062.e5 (2017).

Bashiardes, S., Shapiro, H., Rozin, S., Shibolet, O. & Elinav, E. Non-alcoholic fatty liver and the gut microbiota. Mol. Metab. 5, 782–794 (2016).

Cohen, L. J. et al. Commensal bacteria make GPCR ligands that mimic human signalling molecules. Nature 549, 48–53 (2017).

Schubert, K., Olde Damink, S. W. M., von Bergen, M. & Schaap, F. G. Interactions between bile salts, gut microbiota, and hepatic innate immunity. Immunol. Rev. 279, 23–35 (2017).

Marra, F. & Svegliati-Baroni, G. Lipotoxicity and the gut–liver axis in NASH pathogenesis. J. Hepatol. 68, 280–295 (2018).

Brandl, K. & Schnabl, B. Intestinal microbiota and nonalcoholic steatohepatitis. Curr. Opin. Gastroenterol. 33, 128–133 (2017).

Leung, C., Rivera, L., Furness, J. B. & Angus, P. W. The role of the gut microbiota in NAFLD. Nat. Rev. Gastroenterol. Hepatol. 13, 412–425 (2016).

Tsuchida, T. & Friedman, S. L. Mechanisms of hepatic stellate cell activation. Nat. Rev. Gastroenterol. Hepatol. 14, 397–411 (2017).

Lade, A., Noon, L. A. & Friedman, S. L. Contributions of metabolic dysregulation and inflammation to nonalcoholic steatohepatitis, hepatic fibrosis, and cancer. Curr. Opin. Oncol. 26, 100–107 (2014).

Wang, X. et al. Hepatocyte TAZ/WWTR1 promotes inflammation and fibrosis in nonalcoholic steatohepatitis. Cell Metab. 24, 848–862 (2016).

Valenti, L. & Dongiovanni, P. Mutant PNPLA3 I148M protein as pharmacological target for liver disease. Hepatology 66, 1026–1028 (2017).

Oseini, A. M., Cole, B. K., Issa, D., Feaver, R. E. & Sanyal, A. J. Translating scientific discovery: the need for preclinical models of nonalcoholic steatohepatitis. Hepatol. Int. 12, 6–16 (2018).

Feaver, R. E. et al. Development of an in vitro human liver system for interrogating nonalcoholic steatohepatitis. JCI Insight 1, e90954 (2016).

Nakagawa, S. et al. Molecular liver cancer prevention in cirrhosis by organ transcriptome analysis and lysophosphatidic acid pathway inhibition. Cancer Cell 30, 879–890 (2016).

Nguyen, D. G. et al. Bioprinted 3D primary liver tissues allow assessment of organ-level response to clinical drug induced toxicity in vitro. PLoS One 11, e0158674 (2016).

Santhekadur, P. K., Kumar, D. P. & Sanyal, A. J. Preclinical models of non-alcoholic fatty liver disease. J. Hepatol. 68, 230–237 (2018).

Tsuchida, T. et al. A simple diet- and chemical-induced murine NASH model with rapid progression of steatohepatitis, fibrosis and liver cancer. J. Hepatol. https://doi.org/10.1016/j.jhep.2018.03.011 (2018).

Charlton, M. et al. Fast food diet mouse: novel small animal model of NASH with ballooning, progressive fibrosis, and high physiological fidelity to the human condition. Am. J. Physiol. Gastrointest. Liver Physiol. 301, G825–G834 (2011).

Giles, D. A. et al. Thermoneutral housing exacerbates nonalcoholic fatty liver disease in mice and allows for sex-independent disease modeling. Nat. Med. 23, 829–838 (2017).

Anstee, Q. M. & Goldin, R. D. Mouse models in non-alcoholic fatty liver disease and steatohepatitis research. Int. J. Exp. Pathol. 87, 1–16 (2006).

Sanyal, A. J. & Pacana, T. A lipidomic readout of disease progression in a diet-induced mouse model of nonalcoholic fatty liver disease. Trans. Am. Clin. Climatol. Assoc. 126, 271–288 (2015).

Lai, C. Y., Lin, C. Y., Hsu, C. C., Yeh, K. Y. & Her, G. M. Liver-directed microRNA-7a depletion induces nonalcoholic fatty liver disease by stabilizing YY1-mediated lipogenic pathways in zebrafish. Biochim. Biophys. Acta 1863, 844–856 (2018).

Musselman, L. P. et al. Role of fat body lipogenesis in protection against the effects of caloric overload in Drosophila. J. Biol. Chem. 288, 8028–8042 (2013).

Lee, L. et al. Nutritional model of steatohepatitis and metabolic syndrome in the Ossabaw miniature swine. Hepatology 50, 56–67 (2009).

Sternson, S. M. & Eiselt, A. K. three pillars for the neural control of appetite. Annu. Rev. Physiol. 79, 401–423 (2017).

Vilar-Gomez, E. et al. Weight loss through lifestyle modification significantly reduces features of nonalcoholic steatohepatitis. Gastroenterology 149, 367–378.e5 (2015).

Mahady, S. E., Webster, A. C., Walker, S., Sanyal, A. & George, J. The role of thiazolidinediones in non-alcoholic steatohepatitis—a systematic review and meta analysis. J. Hepatol. 55, 1383–1390 (2011).

Ratziu, V. et al. Long-term efficacy of rosiglitazone in nonalcoholic steatohepatitis: results of the fatty liver improvement by rosiglitazone therapy (FLIRT 2) extension trial. Hepatology 51, 445–453 (2010).

Mudaliar, S. et al. Efficacy and safety of the farnesoid X receptor agonist obeticholic acid in patients with type 2 diabetes and nonalcoholic fatty liver disease. Gastroenterology 145, 574–582.e1 (2013).

Kong, B., Luyendyk, J. P., Tawfik, O. & Guo, G. L. Farnesoid X receptor deficiency induces nonalcoholic steatohepatitis in low-density lipoprotein receptor–knockout mice fed a high-fat diet. J. Pharmacol. Exp. Ther. 328, 116–122 (2009).

Neuschwander-Tetri, B. A. et al. Farnesoid X nuclear receptor ligand obeticholic acid for non-cirrhotic, non-alcoholic steatohepatitis (FLINT): a multicentre, randomised, placebo-controlled trial. Lancet 385, 956–965 (2015).

Nies, V. J. et al. Fibroblast growth factor signaling in metabolic regulation. Front. Endocrinol. (Lausanne) 6, 193 (2016).

Hartmann, P. et al. Modulation of the intestinal bile acid/FXR/FGF15 axis improves alcoholic liver disease in mice. Hepatology 67, 2150–2166 (2018).

Jiang, C. et al. Intestinal farnesoid X receptor signaling promotes nonalcoholic fatty liver disease. J. Clin. Invest. 125, 386–402 (2015).

Harrison, S. A. et al. NGM282 for treatment of non-alcoholic steatohepatitis: a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial. Lancet 391, 1174–1185 (2018).

Staiger, H., Keuper, M., Berti, L., Hrabe de Angelis, M. & Häring, H. U. Fibroblast growth factor 21-metabolic role in mice and men. Endocr. Rev. 38, 468–488 (2017).

Jinnouchi, H. et al. Liraglutide, a glucagon-like peptide-1 analog, increased insulin sensitivity assessed by hyperinsulinemic-euglycemic clamp examination in patients with uncontrolled type 2 diabetes mellitus. J. Diabetes Res. 2015, 706416 (2015).

Armstrong, M. J. et al. Liraglutide safety and efficacy in patients with non-alcoholic steatohepatitis (LEAN): a multicentre, double-blind, randomised, placebo-controlled phase 2 study. Lancet 387, 679–690 (2016).

Ratziu, V. et al. Elafibranor, an agonist of the peroxisome proliferator–activated receptor–α and –δ, induces resolution of nonalcoholic steatohepatitis without fibrosis worsening. Gastroenterology 150, 1147–1159.e5 (2016).

Kim, C. W. et al. Acetyl CoA carboxylase inhibition reduces hepatic steatosis but elevates plasma triglycerides in mice and humans: a bedside to bench investigation. Cell Metab. 26, 394–406.e6 (2017).

Taub, R. et al. Lipid lowering in healthy volunteers treated with multiple doses of MGL-3196, a liver-targeted thyroid hormone receptor-β agonist. Atherosclerosis 230, 373–380 (2013).

Alvarado, T. F. et al. Thyroid hormone receptor β agonist induces β-catenin-dependent hepatocyte proliferation in mice: implications in hepatic regeneration. Gene Expr. 17, 19–34 (2016).

Alkhouri, N., Carter-Kent, C. & Feldstein, A. E. Apoptosis in nonalcoholic fatty liver disease: diagnostic and therapeutic implications. Expert Rev. Gastroenterol. Hepatol. 5, 201–212 (2011).

Barreyro, F. J. et al. The pan-caspase inhibitor Emricasan (IDN-6556) decreases liver injury and fibrosis in a murine model of non-alcoholic steatohepatitis. Liver Int. 35, 953–966 (2015).

Loomba, R. et al. The ASK1 inhibitor selonsertib in patients with nonalcoholic steatohepatitis: a randomized, phase 2 trial. Hepatology (2017).

Friedman, S. L. et al. A randomized, placebo-controlled trial of cenicriviroc for treatment of nonalcoholic steatohepatitis with fibrosis. Hepatology 67, 1754–1767 (2018).

Puri, P. & Sanyal, A. J. The intestinal microbiome in nonalcoholic fatty liver disease. Clin. Liver Dis. 22, 121–132 (2018).

Ahmadian, M. et al. ERRγ preserves brown fat innate thermogenic activity. Cell Rep. 22, 2849–2859 (2018).

Carino, A. et al. BAR502, a dual FXR and GPBAR1 agonist, promotes browning of white adipose tissue and reverses liver steatosis and fibrosis. Sci. Rep. 7, 42801 (2017).

Perry, R. J., Zhang, D., Zhang, X. M., Boyer, J. L. & Shulman, G. I. Controlled-release mitochondrial protonophore reverses diabetes and steatohepatitis in rats. Science 347, 1253–1256 (2015).

Safadi, R. et al. The fatty acid–bile acid conjugate Aramchol reduces liver fat content in patients with nonalcoholic fatty liver disease. Clin. Gastroenterol. Hepatol. 12, 2085–2091.e1 (2014).

Woodcock, J., Griffin, J. P. & Behrman, R. E. Development of novel combination therapies. N. Engl. J. Med. 364, 985–987 (2011).

Wooden, B., Goossens, N., Hoshida, Y. & Friedman, S. L. Using big data to discover diagnostics and therapeutics for gastrointestinal and liver diseases. Gastroenterology 152, 53–67 (2017).

Konerman, M. A., Jones, J. C. & Harrison, S. A. Pharmacotherapy for NASH: current and emerging. J. Hepatol. 68, 362–375 (2018).

Patel, Y. A. et al. Baseline parameters in clinical trials for nonalcoholic steatohepatitis: recommendations from the liver forum. Gastroenterology 153, 621–625.e7 (2017).

Sanyal, A. J. et al. Challenges and opportunities in drug and biomarker development for nonalcoholic steatohepatitis: findings and recommendations from an American Association for the Study of Liver Diseases–U.S. Food and Drug Administration Joint Workshop. Hepatology 61, 1392–1405 (2015).

Drew, L. Drug development: sprint finish. Nature 551 https://doi.org/10.1038/d41586-017-06926-1 (2017).

Haflidadottir, S. et al. Long-term follow-up and liver-related death rate in patients with non-alcoholic and alcoholic related fatty liver disease. BMC Gastroenterol. 14, 166 (2014).

Weltman, M. D., Farrell, G. C. & Liddle, C. Increased hepatocyte CYP2E1 expression in a rat nutritional model of hepatic steatosis with inflammation. Gastroenterology 111, 1645–1653 (1996).

Matsumoto, M. et al. An improved mouse model that rapidly develops fibrosis in non-alcoholic steatohepatitis. Int. J. Exp. Pathol. 94, 93–103 (2013).

Clapper, J. R. et al. Diet-induced mouse model of fatty liver disease and nonalcoholic steatohepatitis reflecting clinical disease progression and methods of assessment. Am. J. Physiol. Gastrointest. Liver Physiol. 305, G483–G495 (2013).

Zhang, Y. et al. Positional cloning of the mouse obese gene and its human homologue. Nature 372, 425–432 (1994).

Hummel, K. P., Dickie, M. M. & Coleman, D. L. Diabetes, a new mutation in the mouse. Science 153, 1127–1128 (1966).

Oana, F. et al. Physiological difference between obese (fa/fa) Zucker rats and lean Zucker rats concerning adiponectin. Metabolism 54, 995–1001 (2005).

Arsov, T. et al. Adaptive failure to high-fat diet characterizes steatohepatitis in Alms1 mutant mice. Biochem. Biophys. Res. Commun. 342, 1152–1159 (2006).

Nakayama, H. et al. Transgenic mice expressing nuclear sterol regulatory element–binding protein 1c in adipose tissue exhibit liver histology similar to nonalcoholic steatohepatitis. Metabolism 56, 470–475 (2007).

Nakagawa, H. et al. ER stress cooperates with hypernutrition to trigger TNF-dependent spontaneous HCC development. Cancer Cell 26, 331–343 (2014).

Subramanian, S. et al. Dietary cholesterol exacerbates hepatic steatosis and inflammation in obese LDL receptor–deficient mice. J. Lipid Res. 52, 1626–1635 (2011).

Horie, Y. et al. Hepatocyte-specific Pten deficiency results in steatohepatitis and hepatocellular carcinomas. J. Clin. Invest. 113, 1774–1783 (2004).

Fujii, M. et al. A murine model for non-alcoholic steatohepatitis showing evidence of association between diabetes and hepatocellular carcinoma. Med. Mol. Morphol. 46, 141–152 (2013).

Adams, L. A., Sanderson, S., Lindor, K. D. & Angulo, P. The histological course of nonalcoholic fatty liver disease: a longitudinal study of 103 patients with sequential liver biopsies. J. Hepatol. 42, 132–138 (2005).

Angulo, P., Keach, J. C., Batts, K. P. & Lindor, K. D. Independent predictors of liver fibrosis in patients with nonalcoholic steatohepatitis. Hepatology 30, 1356–1362 (1999).

Ratziu, V. et al. Liver fibrosis in overweight patients. Gastroenterology 118, 1117–1123 (2000).

Mantovani, A., Ballestri, S., Lonardo, A. & Targher, G. Cardiovascular disease and myocardial abnormalities in nonalcoholic fatty liver disease. Dig. Dis. Sci. 61, 1246–1267 (2016).

Targher, G., Byrne, C. D., Lonardo, A., Zoppini, G. & Barbui, C. Non-alcoholic fatty liver disease and risk of incident cardiovascular disease: A meta-analysis. J. Hepatol. 65, 589–600 (2016).