title: Overload induced heat shock proteins (HSPs), MAPK and miRNA (miR-1 and miR133a) response in insulin-resistant skeletal muscle.
abstract: BACKGROUND
  Insulin resistance (IR) may decrease muscle adaptability. Heat shock proteins (HSPs), mitogen-activated protein kinases (MAPKs), and miRNA are thought to play a role in muscle hypertrophy but it is unclear if IR may affect their regulation.
  
  
  METHODS
  Soleus muscles of lean Zucker (LZ) and insulin resistant obese Zucker (OZ) rats were overloaded for 7 or 21 days and subjected to immunoblotting and RT-PCR.
  
  
  RESULTS
  IR was associated with decreased muscle hypertrophy. Overload increased HSP27 phosphorylation in both the LZ and OZ rats at day 7 but only in the LZ at day 21. IR was associated with diminished overload induced MAPK phosphorylation and decreased expression of miR-1 and miR133. Overload decreased mir-1 levels in both the LZ and OZ but to a greater extent in the LZ animals.
  
  
  CONCLUSIONS
  These results suggest that alterations in the regulation of HSPs, MAPKs and miRNA may be associated with the diminished hypertrophy of IR muscle.
authors.affiliation: Department of Pharmacology, Physiology and Toxicology, Marshall University, Joan C. Edwards School of Medicine, Huntington, WV 25755-1090, USA.
authors.forename: Anjaiah
authors.initials: A
authors.lastname: Katta
authors.forename: Srinivasarao
authors.initials: S
authors.lastname: Thulluri
authors.forename: Nandini D P K
authors.initials: ND
authors.lastname: Manne
authors.forename: Hari S
authors.initials: HS
authors.lastname: Addagarla
authors.forename: Ravikumar
authors.initials: R
authors.lastname: Arvapalli
authors.forename: Siva K
authors.initials: SK
authors.lastname: Nalabotu
authors.forename: Muralikrishna
authors.initials: M
authors.lastname: Gadde
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Rice
authors.forename: Eric R
authors.initials: ER
authors.lastname: Blough
mesh_terms: D000818:Animals; D005121:Extremities / Q000502:physiology; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism; D006984:Hypertrophy / Q000473:pathology; D007333:Insulin Resistance; D035683:MicroRNAs / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D010766:Phosphorylation; D051381:Rats; D011924:Rats, Zucker
chemical_list: D055551:HSP27 Heat-Shock Proteins; C542191:MIRN1 microRNA, rat; C549446:MIRN133 microRNA, rat; D035683:MicroRNAs; D020928:Mitogen-Activated Protein Kinases