title: Moesin is activated in cardiomyocytes in experimental autoimmune myocarditis and mediates cytoskeletal reorganization with protrusion formation.
abstract: Acute myocarditis is a self-limiting disease. Most patients with myocarditis recover without cardiac dysfunction in spite of limited capacity of myocardial regeneration. Therefore, to address intrinsic reparative machinery of inflamed hearts, we investigated the cellular dynamics of cardiomyocytes in response to inflammation using experimental autoimmune myocarditis (EAM) model. EAM was induced by immunization of BALB/c mice with α-myosin heavy chain peptides twice. The inflammatory reaction was evoked with myocardial damage with the peak at 3 wk after the first immunization (EAM3w). Morphological and functional restoration started from EAM3w, when active protrusion formation, a critical process of myocardial healing, was observed in cardiomyocytes. Shotgun proteomics revealed that cytoskeletal proteins were preferentially increased in cardiomyocytes at EAM3w, compared with preimmunized (EAM0w) hearts, and that moesin was the most remarkably upregulated among them. Immunoblot analyses demonstrated that the expression of both total and phosphorylated moesin was upregulated in isolated cardiomyocytes from EAM3w hearts. Immunofluorescence staining showed that moesin was localized at cardiomyocyte protrusions at EAM3w. Adenoviral vectors expressing wild-type, constitutively active and inactive form of moesin (wtMoesin, caMoesin, and iaMoesin, respectively) were transfected in neonatal rat cardiomyocytes. The overexpression of wtMoesin and caMoesin resulted in protrusion formation, while not iaMoesin. Finally, we found that cardiomyocyte protrusions were accompanied by cell-cell contact formation. The expression of moesin was upregulated in cardiomyocytes under inflammation, inducing protrusion formation in a phosphorylation-dependent fashion. Moesin signal could be a novel therapeutic target that stimulates myocardial repair by promoting contact formation of cardiomyocytes.
authors.affiliation: Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Osaka, Japan;
authors.forename: Akimitsu
authors.initials: A
authors.lastname: Miyawaki
authors.affiliation: Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Osaka, Japan;
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Mitsuhara
authors.affiliation: Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Osaka, Japan;
authors.forename: Aya
authors.initials: A
authors.lastname: Orimoto
authors.affiliation: Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Osaka, Japan;
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nakayasu
authors.affiliation: Laboratory of Biopharmaceutical Research, National Institutes of Biomedical Innovation, Health and Nutrition, Saitoasagi, Ibaraki, Osaka, Japan; and.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Tsunoda
authors.affiliation: Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Osaka, Japan;
authors.forename: Masanori
authors.initials: M
authors.lastname: Obana
authors.affiliation: Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Osaka, Japan;
authors.forename: Makiko
authors.initials: M
authors.lastname: Maeda
authors.affiliation: Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Osaka, Japan;
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakayama
authors.affiliation: Department of Toxicology and Safety Science, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Osaka, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshioka
authors.affiliation: Department of Toxicology and Safety Science, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Osaka, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Tsutsumi
authors.affiliation: Laboratory of Clinical Science and Biomedicine, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Osaka, Japan; fujio@phs.osaka-u.ac.jp.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Fujio
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001327:Autoimmune Diseases / Q000139:chemically induced / Q000378:metabolism*; D022081:Cell Surface Extensions / Q000235:genetics* / Q000473:pathology; D002470:Cell Survival; D003599:Cytoskeleton / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D004452:Echocardiography; D005455:Fluorescent Antibody Technique; D015151:Immunoblotting; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D009205:Myocarditis / Q000139:chemically induced / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology; D018995:Myosin Heavy Chains / Q000009:adverse effects; D010455:Peptides; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D008840:Microfilament Proteins; D010455:Peptides; D010750:Phosphoproteins; C071058:moesin; D018995:Myosin Heavy Chains
keywords: cardiomyocyte; moesin; myocarditis; protrusion; shotgun proteomics