title: Calcyclin binding protein promotes DNA synthesis and differentiation in rat neonatal cardiomyocytes.
abstract: During cardiac muscle development, most cardiomyocytes permanently withdraw from the cell cycle. Previously, by suppressive subtractive hybridization, we identified calcyclin-binding protein/Siah-interacting protein (CacyBP/SIP) as one of the candidates being upregulated in the hyperplastic to hypertrophic switch, suggesting an important role of CacyBP/SIP in cardiac development. To show the importance of CacyBP/SIP during myoblast differentiation, we report here that CacyBP/SIP is developmentally regulated in postnatal rat hearts. The overexpression of CacyBP/SIP promotes the differentiation and DNA synthesis of H9C2 cells and primary rat cardiomyocytes, as well as downregulates the expression of beta-catenin. Besides, CacyBP/SIP promotes the formation of myotubes and multinucleation upon differentiation. To investigate the cardioprotective role of CacyBP/SIP in cardiomyocytes, a hypoxia/reoxygenation model was employed. We found that CacyBP/SIP was upregulated during myocardial infarction (MI) and hypoxia/reoxygenation. As a conclusion, CacyBP/SIP may play a role in cardiomyogenic differentiation and possibly protection of cardiomyocytes during hypoxia/reoxygenation injury.
authors.affiliation: Department of Biochemistry and Croucher Laboratory for Human Genomics, The Chinese University of Hong Kong, Shatin, NT, China.
authors.forename: Ka-Wing
authors.initials: KW
authors.lastname: Au
authors.forename: Cecy Y C
authors.initials: CY
authors.lastname: Kou
authors.forename: Anthony Y H
authors.initials: AY
authors.lastname: Woo
authors.forename: Stephen S C
authors.initials: SS
authors.lastname: Chim
authors.forename: Kwok-Pui
authors.initials: KP
authors.lastname: Fung
authors.forename: Christopher H K
authors.initials: CH
authors.lastname: Cheng
authors.forename: Mary M Y
authors.initials: MM
authors.lastname: Waye
authors.forename: Stephen K W
authors.initials: SK
authors.lastname: Tsui
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002316:Cardiotonic Agents; D002453:Cell Cycle; D002454:Cell Differentiation; D015687:Cell Hypoxia; D002478:Cells, Cultured; D003402:Creatine Kinase / Q000378:metabolism; D003470:Culture Media; D004247:DNA / Q000096:biosynthesis*; D004261:DNA Replication; D015536:Down-Regulation / Q000235:genetics; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D047908:Intracellular Signaling Peptides and Proteins; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation / Q000235:genetics; D051176:beta Catenin / Q000235:genetics
chemical_list: C491777:CacyBP protein, rat; D002135:Calcium-Binding Proteins; D002316:Cardiotonic Agents; D003470:Culture Media; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D051176:beta Catenin; D004247:DNA; D003402:Creatine Kinase