title: Hsp70 prevents disuse muscle atrophy in senescent rats.
abstract: This study determined the effects of heat shock protein 70 (Hsp70) overexpression on disuse muscle atrophy in senescent rats. Solei of young and senescent rats were co-injected with Hsp70 plus a nuclear factor kappa B (NF-kappaBeta) reporter plasmid. After 4 days, the hind limbs of half the young and senescent rats were immobilized for 6 days with the remainder serving as weight bearing controls. Hsp70 protein levels and cross-sectional area decreased in both groups (~20%) after immobilization. Atrophy was prevented in those fibers overexpressing Hsp70. NF-kappaBeta activity increased in the soleus of both young (three-fold) and senescent (five-fold) animals after immobilization and was prevented by Hsp70 overexpression. Inhibitor of kappaBeta decreased in young (~30%) and senescent (~10%) animals with immobilization and returned to normal with Hsp70. Heat shock protein 70 overexpression prevents disuse atrophy in senescent rats, possibly through suppression of the NF-kappaB pathway.
authors.affiliation: Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, 32611, USA. sdodd@hhp.ufl.edu
authors.forename: Stephen
authors.initials: S
authors.lastname: Dodd
authors.forename: Brian
authors.initials: B
authors.lastname: Hain
authors.forename: Andrew
authors.initials: A
authors.lastname: Judge
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D007103:Immobilization; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000378:metabolism / Q000473:pathology; D020966:Muscular Disorders, Atrophic / Q000235:genetics / Q000378:metabolism*; D000072000:NF-KappaB Inhibitor alpha; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D018840:HSP70 Heat-Shock Proteins; D020672:I-kappa B Proteins; C000606204:NFKBIA protein, human; C000606206:Nfkbia protein, rat; D000072000:NF-KappaB Inhibitor alpha