920 Martí-Rodrigo A, et al. Gut 2020;69:920–932. doi:10.1136/gutjnl-2019-318372 Hepatology ORIGINAL RESEARCH Rilpivirine attenuates liver fbrosis through selective STAT1-mediated apoptosis in hepatic stellate cells Alberto Martí-Rodrigo , 1 Fernando Alegre, 1,2 Ángela B Moragrega, 1 Francisco García-García, 3 Pablo Martí-Rodrigo , 1 Anabel Fernández-Iglesias, 4 Jordi Gracia-Sancho , 4,5 Nadezda Apostolova, 1 Juan V Esplugues, 1,2 Ana Blas-García 1 To cite: Martí-Rodrigo A, Alegre F, Moragrega ÁB, et al. Gut 2020;69:920–932. ► Additional material is published online only. To view, please visit the journal online (http://dx.doi.org/10.1136/ gutjnl-2019-318372) 1 Department of Pharmacology, Faculty of Medicine, University of Valencia-CIBERehd, Valencia, Spain 2 FISABIO-Hospital Universitario Dr. Peset, Valencia, Spain 3 Bioinformatics & Biostatistics Unit, Principe Felipe Research Center, Valencia, Spain 4 Liver Vascular Biology Research Group, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)-CIBERehd, Barcelona, Spain 5 Hepatology, Department of Biomedical Research, Inselspital, University of Bern, Bern, Switzerland Correspondence to Dr Ana Blas-García, Department of Pharmacology, Faculty of Medicine, University of Valencia- CIBERehd, Avenida Blasco Ibáñez, 15-17, Valencia 46010, Spain; ana.blas@uv.es JVE and AB-G are joint senior authors. Received 25 January 2019 Revised 8 August 2019 Accepted 15 August 2019 Published Online First 17 September 2019 © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ. Significance of this study What is already known on this subject? ► Liver fbrosis represents a common process in the majority of chronic liver diseases, characterised by the net accumulation of extracellular matrix. ► Activation of hepatic stellate cells (HSC) is a complex process that plays a central role in liver fbrosis. ► Due to the lack of effective antifbrotic therapies, identifcation of novel and cell type- specifc therapeutic approaches is needed to control this important disease. What are the new findings? ► Chronic administration of rilpivirine (RPV) exerts protective properties in the liver, and reduces fbrosis and liver disease progression, regardless of its aetiology. ► RPV selectively triggers activated HSC inactivation and apoptosis through signal transducer and activator of transcription (STAT)1 activation, and induces that of STAT3 in hepatocytes, thus promoting the regeneration of liver parenchyma. ► Enhanced hepatocyte proliferation is dependent on and secondary to its pro-apoptotic effect in HSC. How might it impact on clinical practice in the foreseeable future? ► Specifc induction of STAT1-mediated apoptosis in activated HSC by RPV constitutes a novel and potentially highly effective strategy to attenuate liver fbrosis and promote liver regeneration. ABSTRACT Objective Liver fbrosis constitutes a major health problem worldwide due to its rapidly increasing prevalence and the lack of specifc and effective treatments. Growing evidence suggests that signalling through cytokine-activated Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathways regulates liver fbrosis and regeneration. Rilpivirine (RPV) is a widely used anti-HIV drug not reported to produce hepatotoxicity. We aimed to describe the potential hepatoprotective effects of RPV in different models of chronic liver injury, focusing on JAK-STAT signalling regulation. Design The effects of RPV on hepatic steatosis, infammation and fbrogenesis were studied in a nutritional mouse model of non-alcoholic fatty liver disease, carbon tetrachloride-induced fbrosis and bile duct ligation-induced fbrosis. Primary human hepatic stellate cells (hHSC) and human cell lines LX-2 and Hep3B were used to investigate the underlying molecular mechanisms. Results RPV exerted a clear anti-infammatory and antifbrotic effect in all the in vivo models of liver injury employed, and enhanced STAT3-dependent proliferation in hepatocytes and apoptosis in HSC through selective STAT1 activation. These results were reproduced in vitro; RPV undermined STAT3 activation and triggered STAT1- mediated pathways and apoptosis in HSC. Interestingly, this selective pro-apoptotic effect completely disappeared when STAT1 was silenced. Conditioned medium experiments showed that HSC apoptosis activated STAT3 in hepatocytes in an interleukin-6- dependent mechanism. Conclusion RPV ameliorates liver fbrosis through selective STAT1-dependent induction of apoptosis in HSC, which exert paracrinal effects in hepatocytes, thus promoting liver regeneration. RPV’s actions may represent an effective strategy to treat chronic liver diseases of different aetiologies and help identify novel therapeutic targets. INTRODUCTION Liver fibrosis, a serious health problem world- wide whose prevalence continues to rise, can be caused by several aetiologies, and is characterised by excessive deposition of extracellular matrix, loss of parenchymal structure and organ dysfunction. Unfortunately, there is no cure for this disease, which can progress to cirrhosis, hepatocarcinoma and even death. 1 Therefore, there is great interest in developing new effective therapies, with drug repurposing or use of compounds with pleiotropic effects approved for other therapeutic uses repre- senting one of the main strategies. In this way, drugs whose toxicological profile and bioavailability have already been validated are analysed to determine their potential antifibrotic effects. Rilpivirine (RPV) on September 16, 2020 at Uni of Valencia Consortia. Protected by copyright. http://gut.bmj.com/ Gut: first published as 10.1136/gutjnl-2019-318372 on 17 September 2019. Downloaded from