title: p66Shc links alpha1-adrenergic receptors to a reactive oxygen species-dependent AKT-FOXO3A phosphorylation pathway in cardiomyocytes.
abstract: p66Shc is an adapter protein that is induced by hypertrophic stimuli and has been implicated as a major regulator of reactive oxygen species (ROS) production and cardiovascular oxidative stress responses. This study implicates p66Shc in an alpha(1)-adrenergtic receptor (alpha(1)-AR) pathway that requires the cooperative effects of protein kinase (PK)Cepsilon and PKCdelta and leads to AKT-FOXO3a phosphorylation in cardiomyocytes. alpha(1)-ARs promote p66Shc-YY(239/240) phosphorylation via a ROS-dependent mechanism that is localized to caveolae and requires epidermal growth factor receptor (EGFR) and PKCepsilon activity. alpha(1)-ARs also increase p66Shc-S(36) phosphorylation via an EGFR transactivation pathway involving PKCdelta. p66Shc links alpha(1)-ARs to an AKT signaling pathway that selectively phosphorylates/inactivates FOXO transcription factors and downregulates the ROS-scavenging protein manganese superoxide dismutase (MnSOD); the alpha(1)-AR-p66Shc-dependent pathway involving AKT does not regulate GSK3. Additional studies show that RNA interference-mediated downregulation of endogenous p66Shc leads to the derepression of FOXO3a-regulated genes such as MnSOD, p27Kip1, and BIM-1. p66Shc downregulation also increases proliferating cell nuclear antigen expression and induces cardiomyocyte hypertrophy, suggesting that p66Shc exerts an antihypertrophic action in neonatal cardiomyocytes. The novel alpha(1)-AR- and ROS-dependent pathway involving p66Shc identified in this study is likely to contribute to cardiomyocyte remodeling and the evolution of heart failure.
authors.affiliation: Department of Pharmacology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
authors.forename: Jianfen
authors.initials: J
authors.lastname: Guo
authors.forename: Zoya
authors.initials: Z
authors.lastname: Gertsberg
authors.forename: Nazira
authors.initials: N
authors.lastname: Ozgen
authors.forename: Susan F
authors.initials: SF
authors.lastname: Steinberg
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000903:Antibiotics, Antineoplastic / Q000633:toxicity; D017209:Apoptosis; D006332:Cardiomegaly / Q000378:metabolism; D021941:Caveolae / Q000378:metabolism; D049108:Cell Enlargement; D002478:Cells, Cultured; D004317:Doxorubicin / Q000633:toxicity; D066246:ErbB Receptors / Q000378:metabolism; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D009638:Norepinephrine / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010766:Phosphorylation; D051745:Protein Kinase C-delta / Q000378:metabolism; D051744:Protein Kinase C-epsilon / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*; D055765:Shc Signaling Adaptor Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D013997:Time Factors; D014161:Transduction, Genetic
chemical_list: D000903:Antibiotics, Antineoplastic; C499515:FOXO3 protein, rat; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D018340:Receptors, Adrenergic, alpha-1; D055765:Shc Signaling Adaptor Proteins; C528035:Shc1 protein, rat; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D004317:Doxorubicin; C483803:Egfr protein, rat; D066246:ErbB Receptors; D051057:Proto-Oncogene Proteins c-akt; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; D038362:Glycogen Synthase Kinase 3; D009638:Norepinephrine