Abstract
NASH is a complex metabolic disease best understood by recognizing the sources and fates of major metabolic substrates (carbohydrates and fatty acids) and how their excess can lead to lipotoxic liver injury with a histological phenotype of NASH. With this perspective, targets of therapy can be predicted. This review summarizes recent clinical trial data and where these trials fit into the substrate overload lipotoxic liver injury paradigm of NASH pathogenesis. Because NASH is likely the result of diverse environmental, genetic, and epigenetic factors that differ among patients, no single therapy is likely to be effective in all patients. Ultimately, rationally designed personalized therapy will be achieved for patients with NASH, but this will require substantial new knowledge on why patients respond to specific therapies, a goal that remains elusive. Hopefully, this gap in knowledge will be addressed by analysis of responders and non-responders in current and future clinical trials.
Similar content being viewed by others
Abbreviations
- NASH:
-
Nonalcoholic steatohepatitis
- NAFLD:
-
Nonalcoholic fatty liver disease
- DNL:
-
De novo lipogenesis
- PPAR:
-
Peroxisomal proliferator activated receptor
- FXR:
-
Farnesol X receptor
- SGLT2:
-
Sodium glucose cotransporter 2
- GLP:
-
Glucagon-like peptide
- DPP:
-
Dipeptidyl dipeptidase-4
- FGF:
-
Fibroblast growth factor
- CoA:
-
Coenzyme A
- SREPBP:
-
Sterol response element binding protein
- ACC:
-
Acetyl-CoA carboxylase
- FAS:
-
Fatty acid synthetase
- SCD:
-
Stearoyl-CoA desaturase
- SAMe:
-
S-adenosylmethionine
- PDE-4:
-
Phosphodiesterase-4
- CCR:
-
Chemokine receptor
- ELF:
-
European liver fibrosis
- Loxl2:
-
Lysl oxidase-like protein 2
References
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
Schaffer JE. Lipotoxicity: when tissues overeat. Curr Opin Lipidol. 2003;14:281–7.
Malhi H, Gores GJ. Molecular mechanisms of lipotoxicity in nonalcoholic fatty liver disease. Semin Liver Dis. 2008;28:360–9.
Neuschwander-Tetri BA. Hepatic lipotoxicity and the pathogenesis of nonalcoholic steatohepatitis: the central role of nontriglyceride fatty acid metabolites. Hepatology. 2010;52:774–88.
Trauner M, Arrese M, Wagner M. Fatty liver and lipotoxicity. Biochim Biophys Acta. 1801;2010:299–310.
Cusi K. Role of obesity and lipotoxicity in the development of nonalcoholic steatohepatitis: pathophysiology and clinical implications. Gastroenterology. 2012;142:711–25.
Leamy AK, Egnatchik RA, Young JD. Molecular mechanisms and the role of saturated fatty acids in the progression of non-alcoholic fatty liver disease. Prog Lipid Res. 2013;52:165–74.
Day CP, James OF. Steatohepatitis: a tale of two “hits”? Gastroenterology. 1998;114:842–5.
Day CP, James OF. Hepatic steatosis: innocent bystander or guilty party? Hepatology. 1998;27:1463–6.
Angulo P, Kleiner DE, Dam-Larsen S, et al. Liver fibrosis, but no other histologic features, is associated with long-term outcomes of patients with nonalcoholic fatty liver disease. Gastroenterology. 2015;149:389–97.
Lassailly G, Caiazzo R, Buob D, et al. Bariatric surgery reduces features of nonalcoholic steatohepatitis in morbidly obese patients. Gastroenterology. 2015;149:379–88.
Ratziu V, Harrison S, Francque S, et al. Elafibranor, an agonist of the peroxisome proliferator−activated receptor−α and −δ, induces resolution of nonalcoholic steatohepatitis without fibrosis worsening. Gastroenterology. 2016. doi:10.1053/j.gastro.2016.01.038. Randomized clinical trial demonstrating a benefit of elafibranor. The benefit appeared more in those with advanced disease.
Cariou B, Hanf R, Lambert-Porcheron S, et al. Dual peroxisome proliferator-activated receptor α/δ agonist GFT505 improves hepatic and peripheral insulin sensitivity in abdominally obese subjects. Diabetes Care. 2013;36:2923–30.
Bojic LA, Huff MW. Peroxisome proliferator-activated receptor δ: a multifaceted metabolic player. Curr Opin Lipidol. 2013;24:171–7.
Risérus U, Sprecher D, Johnson T, et al. Activation of peroxisome proliferator-activated receptor (PPAR)δ promotes reversal of multiple metabolic abnormalities, reduces oxidative stress, and increases fatty acid oxidation in moderately obese men. Diabetes. 2008;57:332–9.
Stefan N, Thamer C, Staiger H, et al. Genetic variations in PPARD and PPARGC1A determine mitochondrial function and change in aerobic physical fitness and insulin sensitivity during lifestyle intervention. J Clin Endocrinol Metab. 2007;92:1827–33.
Sidossis L, Kajimura S. Brown and beige fat in humans: thermogenic adipocytes that control energy and glucose homeostasis. J Clin Invest. 2015;125:478–86.
Xue R, Lynes MD, Dreyfuss JM, et al. Clonal analyses and gene profiling identify genetic biomarkers of the thermogenic potential of human brown and white preadipocytes. Nat Med. 2015;21:760–8.
Shinoda K, Luijten IH, Hasegawa Y, et al. Genetic and functional characterization of clonally derived adult human brown adipocytes. Nat Med. 2015;21:389–94.
Bartelt A, Bruns OT, Reimer R, et al. Brown adipose tissue activity controls triglyceride clearance. Nat Med. 2011;17:200–5.
Rajeev SP, Cuthbertson DJ, Wilding JP. Energy balance and metabolic changes with sodium-glucose co-transporter 2 inhibition. Diabetes Obes Metab. 2016;18:125–34.
Trevaskis JL, Griffin PS, Wittmer C, 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. 2012;302:G762–72.
Armstrong MJ, Gaunt P, Aithal GP, et al. Liraglutide safety and efficacy in patients with non-alcoholic steatohepatitis (LEAN): a multicentre, double-blind, randomised, placebo-controlled phase 2 study. Lancet. 2016;387:679–90. Recent small randomized clinical trial showing a significant beneficial effect of the GLP-1 analogue liraglutide on the resolution of NASH.
Liu JJ, Foo JP, Liu S, et al. The role of fibroblast growth factor 21 in diabetes and its complications: a review from clinical perspective. Diabetes Res Clin Pract. 2015;108:382–9.
Dasarathy S, Yang Y, McCullough AJ, et al. Elevated hepatic fatty acid oxidation, high plasma fibroblast growth factor 21, and fasting bile acids in nonalcoholic steatohepatitis. Eur J Gastroenterol Hepatol. 2011;23:382–8.
Samson SL, Sathyanarayana P, Jogi M, et al. Exenatide decreases hepatic fibroblast growth factor 21 resistance in non-alcoholic fatty liver disease in a mouse model of obesity and in a randomised controlled trial. Diabetologia. 2011;54:3093–100.
Trauner M, Claudel T, Fickert P, et al. Bile acids as regulators of hepatic lipid and glucose metabolism. Dig Dis. 2010;28:220–4.
Cariou B, Bouchaert E, Abdelkarim M, et al. FXR-deficiency confers increased susceptibility to torpor. FEBS Lett. 2007;581:5191–8.
Lefebvre P, Cariou B, Lien F, et al. Role of bile acids and bile acid receptors in metabolic regulation. Physiol Rev. 2009;89:147–91.
Teodoro JS, Rolo AP, Palmeira CM. Hepatic FXR: key regulator of whole-body energy metabolism. Trends Endocrinol Metab. 2011;22:458–66.
Cyphert HA, Ge X, Kohan AB, et al. Activation of the farnesoid X receptor induces hepatic expression and secretion of fibroblast growth factor 21. J Biol Chem. 2012;287:25123–38.
Thomas C, Gioiello A, Noriega L, et al. TGR5-mediated bile acid sensing controls glucose homeostasis. Cell Metab. 2009;10:167–77.
Watanabe M, Houten SM, Mataki C, et al. Bile acids induce energy expenditure by promoting intracellular thyroid hormone activation. Nature. 2006;439:484–9.
Neuschwander-Tetri BA, Loomba R, Sanyal AJ, et al. Farnesoid X nuclear receptor ligand obeticholic acid for non-cirrhotic, non-alcoholic steatohepatitis (FLINT): a multicentre, randomised, placebo-controlled trial. Lancet. 2015;385:956–65. Randomized clinical trial showing that the FXR ligand obeticholic acid improved NASH in some patients but was accompanied by elevations in total and HDL cholesterol.
Erion MD, Cable EE, Ito BR, et al. Targeting thyroid hormone receptor-beta agonists to the liver reduces cholesterol and triglycerides and improves the therapeutic index. Proc Natl Acad Sci U S A. 2007;104:15490–5.
Cable EE, Finn PD, Stebbins JW, et al. Reduction of hepatic steatosis in rats and mice after treatment with a liver-targeted thyroid hormone receptor agonist. Hepatology. 2009;49:407–17.
Perry RJ, Kim T, Zhang XM, et al. Reversal of hypertriglyceridemia, fatty liver disease, and insulin resistance by a liver-targeted mitochondrial uncoupler. Cell Metab. 2013;18:740–8.
Perry RJ, Zhang D, Zhang XM, et al. Controlled-release mitochondrial protonophore reverses diabetes and steatohepatitis in rats. Science. 2015;347:1253–6.
Yehuda-Shnaidman E, Kalderon B, Bar-Tana J. Thyroid hormone, thyromimetics, and metabolic efficiency. Endocr Rev. 2014;35:35–58.
Donnelly KL, Smith CI, Schwarzenberg SJ, et al. Sources of fatty acids stored in liver and secreted via lipoproteins in patients with nonalcoholic fatty liver disease. J Clin Invest. 2005;115:1343–51.
Pickens MK, Yan JS, Ng RK, et al. Dietary sucrose is essential to the development of liver injury in the methionine-choline-deficient model of steatohepatitis. J Lipid Res. 2009;50:2072–82.
Pickens MK, Ogata H, Soon RK, et al. Dietary fructose exacerbates hepatocellular injury when incorporated into a methionine-choline-deficient diet. Liver Int. 2010;30:1229–39.
Safadi R, Konikoff FM, Mahamid M, et al. The fatty acid-bile acid conjugate Aramchol reduces liver fat content in patients with nonalcoholic fatty liver disease. Clin Gastroenterol Hepatol. 2014;12:2085–91.
Flowers MT, Groen AK, Oler AT, et al. Cholestasis and hypercholesterolemia in SCD1-deficient mice fed a low-fat, high-carbohydrate diet. J Lipid Res. 2006;47:2668–80.
Sanyal AJ, Chalasani N, Kowdley KV, et al. Pioglitazone, vitamin E, or placebo for nonalcoholic steatohepatitis. N Engl J Med. 2010;362:1675–85. The PIVENS trial demonstrated improvement in NASH with pioglitazone but with weight gain in some patients. Vitamin E also resulted in improvement in some patients.
Ratziu V, Charlotte F, Bernhardt C, et al. Long-term efficacy of rosiglitazone in nonalcoholic steatohepatitis: results of the fatty liver improvement by rosiglitazone therapy (FLIRT 2) extension trial. Hepatology. 2010;51:445–53.
Bell LN, Wang J, Muralidharan S, et al. Relationship between adipose tissue insulin resistance and liver histology in nonalcoholic steatohepatitis: a pioglitazone versus vitamin E versus placebo for the treatment of nondiabetic patients with nonalcoholic steatohepatitis trial follow-up study. Hepatology. 2012;56:1311–8.
Iyer A, Fairlie DP, Prins JB, et al. Inflammatory lipid mediators in adipocyte function and obesity. Nat Rev Endocrinol. 2010;6:71–82.
Yamaguchi K, Yang L, McCall S, et al. Inhibiting triglyceride synthesis improves hepatic steatosis but exacerbates liver damage and fibrosis in obese mice with nonalcoholic steatohepatitis. Hepatology. 2007;45:1366–74.
Lindor KD, Kowdley KV, Heathcote EJ, et al. Ursodeoxycholic acid for treatment of nonalcoholic steatohepatitis: results of a randomized trial. Hepatology. 2004;39:770–8.
Sanyal AJ, Abdelmalek MF, Suzuki A, et al. No significant effects of ethyl-eicosapentanoic acid on histologic features of nonalcoholic steatohepatitis in a phase 2 trial. Gastroenterology. 2014;147:377–84. No benefit from treatment with this polyunsaturated fatty acid ethyl ester in a large multicenter controlled trial.
Lirussi F, Azzalini L, Orando S, et al. Antioxidant supplements for non-alcoholic fatty liver disease and/or steatohepatitis. Cochrane Database Syst Rev. 2007;4. doi:10.1002/14651858.CD004996.pub3.
Bell LN, Molleston JP, Morton MJ, et al. Hepatic lipid peroxidation and cytochrome P-450 2E1 in pediatric nonalcoholic fatty liver disease and its subtypes. J Clin Gastroenterol. 2011;45:800–7.
Lavine JE, Schwimmer JB, Van Natta ML, et al. Effect of vitamin E or metformin for treatment of nonalcoholic fatty liver disease in children and adolescents: the TONIC randomized controlled trial. JAMA. 2011;305:1659–68. Randomized clinical trial demonstrating the effect of vitamin E in children.
Abdelmalek MF, Sanderson SO, Angulo P, et al. Betaine for nonalcoholic fatty liver disease: results of a randomized placebo-controlled trial. Hepatology. 2009;50:1818–26.
Anstee QM, Day CP. S-adenosylmethionine (SAMe) therapy in liver disease: a review of current evidence and clinical utility. J Hepatol. 2012;57:1097–109.
Puri P, Baillie RA, Wiest MM, et al. A lipidomic analysis of nonalcoholic fatty liver disease. Hepatology. 2007;46:1081–90.
Abu-Shanab A, Quigley EM. The role of the gut microbiota in nonalcoholic fatty liver disease. Nat Rev Gastroenterol Hepatol. 2010;7:691–701.
Feldstein AE. Novel insights into the pathophysiology of nonalcoholic fatty liver disease. Semin Liver Dis. 2010;30:391–401.
Savard C, Tartaglione EV, Kuver R, et al. Synergistic interaction of dietary cholesterol and dietary fat in inducing experimental steatohepatitis. Hepatology. 2013;57:81–92.
Lanaspa MA, Sanchez-Lozada LG, Cicerchi C, et al. Uric acid stimulates fructokinase and accelerates fructose metabolism in the development of fatty liver. PLoS ONE. 2012;7:e47948. doi:10.1371/journal.pone.0047948
Szabo G, Petrasek J. Inflammasome activation and function in liver disease. Nat Rev Gastroenterol Hepatol. 2015;12:387–400.
Wree A, Mehal WZ, Feldstein AE. Targeting cell death and sterile inflammation loop for the treatment of nonalcoholic steatohepatitis. Semin Liver Dis. 2016;36:27–36.
Machado MV, Diehl AM. Pathogenesis of nonalcoholic steatohepatitis. Gastroenterology. 2016. doi:10.1053/j.gastro.2016.02.066. Excellent update on how the reponse to lipotoxic injury plays a role in the outcome.
Ratziu V, Bedossa P, Francque SM, et al. Lack of efficacy of an inhibitor of PDE4 in phase 1 and 2 trials of patients with nonalcoholic steatohepatitis. Clin Gastroenterol Hepatol. 2014;12:1724–30 e5. A potent antiinflammatory phosphodiesterase-4 inhibitor did not improve NASH.
Zein CO, Yerian LM, Gogate P, et al. Pentoxifylline improves nonalcoholic steatohepatitis: a randomized placebo-controlled trial. Hepatology. 2011;54:1610–9.
Van Wagner LB, Koppe SWP, Brunt EM, et al. Pentoxifylline for the treatment of non-alcoholic steatohepatitis: a randomized controlled trial. Ann Hepatol. 2011;10:277–86.
Ratziu V, Sheikh MY, Sanyal AJ, et al. A phase 2, randomized, double-blind, placebo-controlled study of GS-9450 in subjects with nonalcoholic steatohepatitis. Hepatology. 2012;55:419–28.
Barreyro FJ, Holod S, Finocchietto PV, et al. The pan-caspase inhibitor Emricasan (IDN-6556) decreases liver injury and fibrosis in a murine model of non-alcoholic steatohepatitis. Liver Int. 2015;35:953–66.
Traber PG, Zomer E. Therapy of experimental NASH and fibrosis with galectin inhibitors. PLoS ONE. 2013;8:e83481. doi:10.1371/journal.pone.0083481
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of Interest
BANT reports personal fees from Nimbus Therapeutics, Bristol Myers Squibb, Janssen, Conatus, Galmed, Genetech-Roche, and Boehringer-Ingelheim, and personal fees and consultancy for Receptos, Pfizer, and Zafgen, outside the submitted work.
Human and Animal Rights and Informed Consent
All reported studies/experiments with human or animal subjects performed by the authors have been previously published and were in compliance with all applicable ethical standards (including the Helsinki declaration and its amendments, institutional/national research committee standards, and international/national/institutional guidelines).
Additional information
This article is part of the Topical Collection on Fatty Liver Disease
Rights and permissions
About this article
Cite this article
Neuschwander-Tetri, B.A. Future Treatments of NASH. Curr Hepatology Rep 15, 125–133 (2016). https://doi.org/10.1007/s11901-016-0300-3
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11901-016-0300-3