An integrated view of anti-inflammatory and antifibrotic targets for the treatment of NASH

Successful development of treatments for non-alcoholic fatty liver disease and its progressive form, non-alcoholic steatohepatitis (NASH), has been challenging. Because NASH and fibrosis lead to progression towards cirrhosis and clinical outcomes, approaches have either sought to attenuate metabolic dysregulation and cell injury, or directly target the inflammation and fibrosis that ensue. Targets for reducing the activation of inflammatory cascades include nuclear receptor agonists (e.g. resmetirom, lanifibranor, obeticholic acid), modulators of lipotoxicity (e.g. aramchol, acetyl-CoA carboxylase inhibitors) or modification of genetic variants (e.g. PNPLA3 gene silencing). Extrahepatic inflammatory signals from the circulation, adipose tissue or gut are targets of hormonal ag-onists (semaglutide, tirzepatide, FGF19/FGF21 analogues), microbiota or lifestyle interventions. Stress signals and hepatocyte death activate immune responses, engaging innate (macrophages, innate lymphocyte populations) and adaptive (auto-aggressive T cells) mechanisms. Therapies have also been developed to blunt immune cell activation, recruitment (chemokine receptor inhibitors), and responses (e.g. galectin-3 inhibitors, anti-platelet drugs). The disease-driving pathways of NASH converge to elicit fibrosis, which is reversible. The activation of hepatic stellate cells into matrix-producing myofibroblasts can be inhibited by antagonising soluble factors (e.g. integrins, cytokines), cellular crosstalk (e.g. with macrophages), and agonising nuclear receptor signalling. In advanced fibrosis, cell therapy with restorative macrophages or reprogrammed (CAR) T cells may accelerate repair through hepatic stellate cell deactivation or killing, or by enhancing matrix degradation. Heterogeneity of disease - either due to genetics or divergent disease drivers - is an obstacle to defining effective drugs for all patients with NASH that will be overcome incrementally.& COPY; 2023 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Automated summary

The development of treatments for non-alcoholic fatty liver disease and non-alcoholic steatohepatitis (NASH) has been challenging due to the complexity of the disease and the involvement of multiple pathways. Current approaches target metabolic dysregulation, inflammation, fibrosis, and immune responses. Potential therapies include nuclear receptor agonists, lipotoxicity modulators, genetic variant modification, hormonal agonists, microbiota interventions, and lifestyle changes. Inhibiting activation of hepatic stellate cells, immune cell modulation, and cell therapy are strategies to attenuate fibrosis. However, the heterogeneity of NASH poses a challenge in developing effective drugs for all patients.