title: Lysosomal dysfunction and impaired autophagy underlie the pathogenesis of amyloidogenic light chain-mediated cardiotoxicity.
abstract: AL amyloidosis is the consequence of clonal production of amyloidogenic immunoglobulin light chain (LC) proteins, often resulting in a rapidly progressive and fatal amyloid cardiomyopathy. Recent work has found that amyloidogenic LC directly initiate a cardio-toxic response underlying the pathogenesis of the cardiomyopathy; however, the mechanisms that contribute to this proteotoxicity remain unknown. Using human amyloidogenic LC isolated from patients with amyloid cardiomyopathy, we reveal that dysregulation of autophagic flux is critical for mediating amyloidogenic LC proteotoxicity. Restoration of autophagic flux by pharmacological intervention using rapamycin protected against amyloidogenic light chain protein-induced pathologies including contractile dysfunction and cell death at the cellular and organ level and also prolonged survival in an in vivo zebrafish model of amyloid cardiotoxicity. Mechanistically, we identify impaired lysosomal function to be the major cause of defective autophagy and amyloidogenic LC-induced proteotoxicity. Collectively, these findings detail the downstream molecular mechanisms underlying AL amyloid cardiomyopathy and highlight potential targeting of autophagy and lysosomal dysfunction in patients with amyloid cardiomyopathy.
authors.affiliation: Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Guan
authors.affiliation: Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Shikha
authors.initials: S
authors.lastname: Mishra
authors.affiliation: Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Yiling
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Jianru
authors.initials: J
authors.lastname: Shi
authors.affiliation: Department of Medicine, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Trudeau
authors.affiliation: Department of Medicine, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Guy
authors.initials: G
authors.lastname: Las
authors.affiliation: Department of Medicine, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Liesa
authors.affiliation: Department of Medicine, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Orian S
authors.initials: OS
authors.lastname: Shirihai
authors.affiliation: Amyloidosis Center, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Lawreen H
authors.initials: LH
authors.lastname: Connors
authors.affiliation: Amyloidosis Center, Boston University School of Medicine, Boston, MA, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Seldin
authors.affiliation: Cardiac Amyloidosis Program, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Rodney H
authors.initials: RH
authors.lastname: Falk
authors.affiliation: Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Calum A
authors.initials: CA
authors.lastname: MacRae
authors.affiliation: Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA Cardiac Amyloidosis Program, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA rliao@rics.bwh.harvard.edu.
authors.forename: Ronglih
authors.initials: R
authors.lastname: Liao
mesh_terms: D000686:Amyloidosis / Q000473:pathology*; D000818:Animals; D001343:Autophagy; D066126:Cardiotoxicity / Q000503:physiopathology*; D004195:Disease Models, Animal; D007147:Immunoglobulin Light Chains / Q000378:metabolism; D008247:Lysosomes / Q000502:physiology*; D009206:Myocardium / Q000473:pathology; D017208:Rats, Wistar; D016019:Survival Analysis; D015027:Zebrafish
chemical_list: D007147:Immunoglobulin Light Chains
keywords: amyloidosis; autophagy; cardiac toxicity; lysosome; mitochondria