title: Heart failure alters MyoD and MRF4 expressions in rat skeletal muscle.
abstract: Heart failure (HF) is characterized by a skeletal muscle myopathy with increased expression of fast myosin heavy chains (MHCs). The skeletal muscle-specific molecular regulatory mechanisms controlling MHC expression during HF have not been described. Myogenic regulatory factors (MRFs), a family of transcriptional factors that control the expression of several skeletal muscle-specific genes, may be related to these alterations. This investigation was undertaken in order to examine potential relationships between MRF mRNA expression and MHC protein isoforms in Wistar rat skeletal muscle with monocrotaline-induced HF. We studied soleus (Sol) and extensor digitorum longus (EDL) muscles from both HF and control Wistar rats. MyoD, myogenin and MRF4 contents were determined using reverse transcription-polymerase chain reaction while MHC isoforms were separated using polyacrylamide gel electrophoresis. Despite no change in MHC composition of Wistar rat skeletal muscles with HF, the mRNA relative expression of MyoD in Sol and EDL muscles and that of MRF4 in Sol muscle were significantly reduced, whereas myogenin was not changed in both muscles. This down-regulation in the mRNA relative expression of MRF4 in Sol was associated with atrophy in response to HF while these alterations were not present in EDL muscle. Taken together, our results show a potential role for MRFs in skeletal muscle myopathy during HF.
authors.affiliation: Departamento de Morfologia, UNESP, Botucatu, São Paulo, Brazil.
authors.forename: Robson Francisco
authors.initials: RF
authors.lastname: Carvalho
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Cicogna
authors.forename: Gerson Eduardo Rocha
authors.initials: GE
authors.lastname: Campos
authors.forename: Francis da Silva
authors.initials: Fda S
authors.lastname: Lopes
authors.forename: Mário Mateus
authors.initials: MM
authors.lastname: Sugizaki
authors.forename: Célia Regina
authors.initials: CR
authors.lastname: Nogueira
authors.forename: Maeli Dal
authors.initials: MD
authors.lastname: Pai-Silva
mesh_terms: D000818:Animals; D006333:Heart Failure / Q000378:metabolism* / Q000473:pathology; D023421:Models, Animal; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D009133:Muscular Atrophy / Q000378:metabolism; D017570:MyoD Protein / Q000032:analysis / Q000378:metabolism*; D018006:Myogenic Regulatory Factors / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D018008:Myogenin / Q000032:analysis / Q000235:genetics; D018995:Myosin Heavy Chains / Q000032:analysis / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017570:MyoD Protein; D018006:Myogenic Regulatory Factors; D018008:Myogenin; D012333:RNA, Messenger; C063403:myogenic factor 6; D018995:Myosin Heavy Chains