Lisa Longato1, Fausto Andreola2, Sean S Davies3, Jackson L Roberts3, Giuseppe Fusai4, Massimo Pinzani1, Kevin Moore1, Krista Rombouts5. 1. Regenerative Medicine & Fibrosis Group, Institute for Liver & Digestive Health, University College London, Royal Free, London, UK. 2. Liver Failure Group, Institute for Liver & Digestive Health, University College of London, Royal Free, London, UK. 3. Department of Pharmacology, Vanderbilt University, Nashville, TN, USA. 4. Division of Surgery, University College London, Royal Free, London, UK. 5. Regenerative Medicine & Fibrosis Group, Institute for Liver & Digestive Health, University College London, Royal Free, London, UK. Electronic address: k.rombouts@ucl.ac.uk.
Abstract
AIMS: Products of lipid oxidation, such as 4-hydroxynonenal (4-HNE), are key activators of hepatic stellate cells (HSC) to a pro-fibrogenic phenotype. Isolevuglandins (IsoLG) are a family of acyclic γ-ketoaldehydes formed through oxidation of arachidonic acid or as by-products of the cyclooxygenase pathway. IsoLGs are highly reactive aldehydes which are efficient at forming protein adducts and cross-links at concentrations 100-fold lower than 4-hydroxynonenal. Since the contribution of IsoLGs to liver injury has not been studied, we synthesized 15-E2-IsoLG and used it to investigate whether IsoLG could induce activation of HSC. RESULTS: Primary human HSC were exposed to 15-E2-IsoLG for up to 48h. Exposure to 5μM 15-E2-IsoLG in HSCs promoted cytotoxicity and apoptosis. At non-cytotoxic doses (50 pM-500nM) 15-E2-IsoLG promoted HSC activation, indicated by increased expression of α-SMA, sustained activation of ERK and JNK signaling pathways, and increased mRNA and/or protein expression of cytokines and chemokines, which was blocked by inhibitors of JNK and NF-kB. In addition, IsoLG promoted formation of reactive oxygen species, and induced an early activation of ER stress, followed by autophagy. Inhibition of autophagy partially reduced the pro-inflammatory effects of IsoLG, suggesting that it might serve as a cytoprotective response. INNOVATION: This study is the first to describe the biological effects of IsoLG in primary HSC, the main drivers of hepatic fibrosis. CONCLUSIONS: IsoLGs represent a newly identified class of activators of HSC in vitro, which are biologically active at concentrations as low as 500 pM, and are particularly effective at promoting a pro-inflammatory response and autophagy.
AIMS: Products of lipid oxidation, such as 4-hydroxynonenal (4-HNE), are key activators of hepatic stellate cells (HSC) to a pro-fibrogenic phenotype. Isolevuglandins (IsoLG) are a family of acyclic γ-ketoaldehydes formed through oxidation of arachidonic acid or as by-products of the cyclooxygenase pathway. IsoLGs are highly reactive aldehydes which are efficient at forming protein adducts and cross-links at concentrations 100-fold lower than 4-hydroxynonenal. Since the contribution of IsoLGs to liver injury has not been studied, we synthesized 15-E2-IsoLG and used it to investigate whether IsoLG could induce activation of HSC. RESULTS: Primary human HSC were exposed to 15-E2-IsoLG for up to 48h. Exposure to 5μM 15-E2-IsoLG in HSCs promoted cytotoxicity and apoptosis. At non-cytotoxic doses (50 pM-500nM) 15-E2-IsoLG promoted HSC activation, indicated by increased expression of α-SMA, sustained activation of ERK and JNK signaling pathways, and increased mRNA and/or protein expression of cytokines and chemokines, which was blocked by inhibitors of JNK and NF-kB. In addition, IsoLG promoted formation of reactive oxygen species, and induced an early activation of ER stress, followed by autophagy. Inhibition of autophagy partially reduced the pro-inflammatory effects of IsoLG, suggesting that it might serve as a cytoprotective response. INNOVATION: This study is the first to describe the biological effects of IsoLG in primary HSC, the main drivers of hepatic fibrosis. CONCLUSIONS:IsoLGs represent a newly identified class of activators of HSC in vitro, which are biologically active at concentrations as low as 500 pM, and are particularly effective at promoting a pro-inflammatory response and autophagy.
Authors: Sean S Davies; Linda S May-Zhang; Olivier Boutaud; Venkataraman Amarnath; Annet Kirabo; David G Harrison Journal: Pharmacol Ther Date: 2019-10-16 Impact factor: 12.310
Authors: Francesca Zanieri; Ana Levi; David Montefusco; Lisa Longato; Francesco De Chiara; Luca Frenguelli; Sara Omenetti; Fausto Andreola; Tu Vinh Luong; Veronica Massey; Juan Caballeria; Constantino Fondevila; Sriram S Shanmugavelandy; Todd Fox; Giuseppe Mazza; Josepmaria Argemi; Ramon Bataller; Lauren Ashley Cowart; Mark Kester; Massimo Pinzani; Krista Rombouts Journal: Cells Date: 2020-05-16 Impact factor: 6.600
Authors: Giuseppe Mazza; Andrea Telese; Walid Al-Akkad; Luca Frenguelli; Ana Levi; Martina Marrali; Lisa Longato; Kessarin Thanapirom; Maria Giovanna Vilia; Benedetta Lombardi; Claire Crowley; Mark Crawford; Morten A Karsdal; Diana J Leeming; Giusi Marrone; Katrin Bottcher; Benjamin Robinson; Armando Del Rio Hernandez; Domenico Tamburrino; Gabriele Spoletini; Massimo Malago; Andrew R Hall; Jasminka Godovac-Zimmermann; Tu Vinh Luong; Paolo De Coppi; Massimo Pinzani; Krista Rombouts Journal: Cells Date: 2019-12-28 Impact factor: 6.600