title: Modeling human protein aggregation cardiomyopathy using murine induced pluripotent stem cells.
abstract: Several mutations in αB-crystallin (CryAB), a heat shock protein with chaperone-like activities, are causally linked to skeletal and cardiac myopathies in humans. To better understand the underlying pathogenic mechanisms, we had previously generated transgenic (TG) mice expressing R120GCryAB, which recapitulated distinguishing features of the myopathic disorder (e.g., protein aggregates, hypertrophic cardiomyopathy). To determine whether induced pluripotent stem cell (iPSC)-derived cardiomyocytes, a new experimental approach for human disease modeling, would be relevant to aggregation-prone disorders, we decided to exploit the existing transgenic mouse model to derive iPSCs from tail tip fibroblasts. Several iPSC lines were generated from TG and non-TG mice and validated for pluripotency. TG iPSC-derived cardiomyocytes contained perinuclear aggregates positive for CryAB staining, whereas CryAB protein accumulated in both detergent-soluble and insoluble fractions. iPSC-derived cardiomyocytes identified by cardiac troponin T staining were significantly larger when expressing R120GCryAB at a high level in comparison with TG low expressor or non-TG cells. Expression of fetal genes such as atrial natriuretic factor, B-type natriuretic peptide, and α-skeletal α-actin, assessed by quantitative reverse transcription-polymerase chain reaction, were increased in TG cardiomyocytes compared with non-TG, indicating the activation of the hypertrophic genetic program in vitro. Our study demonstrates for the first time that differentiation of R120G iPSCs into cardiomyocytes causes protein aggregation and cellular hypertrophy, recapitulating in vitro key pathognomonic hallmarks found in both animal models and patients. Our findings pave the way for further studies exploiting this cell model system for mechanistic and therapeutic investigations.
authors: University of Utah School of Medicine, Salt Lake City, UT, USA.
authors: Pattraranee
authors: P
authors: Limphong
authors: Huali
authors: H
authors: Zhang
authors: Elisabeth
authors: E
authors: Christians
authors: Qiang
authors: Q
authors: Liu
authors: Michael
authors: M
authors: Riedel
authors: Kathryn
authors: K
authors: Ivey
authors: Paul
authors: P
authors: Cheng
authors: Katie
authors: K
authors: Mitzelfelt
authors: Graydon
authors: G
authors: Taylor
authors: Dennis
authors: D
authors: Winge
authors: Deepak
authors: D
authors: Srivastava
authors: Ivor
authors: I
authors: Benjamin
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000235:genetics / Q000378:metabolism; D002312:Cardiomyopathy, Hypertrophic / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation; D002460:Cell Line; D005786:Gene Expression Regulation; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008822:Mice, Transgenic; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology; D020097:Natriuretic Peptide, Brain / Q000235:genetics / Q000378:metabolism; D055503:Protein Multimerization; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020107:Troponin T / Q000378:metabolism; D038201:alpha-Crystallins / Q000235:genetics / Q000378:metabolism*; D038204:beta-Crystallins / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D020107:Troponin T; D038201:alpha-Crystallins; D038204:beta-Crystallins; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor