title: Inducing Muscle Heat Shock Protein 70 Improves Insulin Sensitivity and Muscular Performance in Aged Mice.
abstract: Heat shock proteins (HSPs) are molecular chaperones with roles in longevity and muscular preservation. We aimed to show elevating HSP70 improves indices of health span. Aged C57/BL6 mice acclimated to a western diet were randomized into: geranylgeranylacetone (GGA)-treated (100 mg/kg/d), biweekly heat therapy (HT), or control. The GGA and HT are well-known pharmacological and environmental inducers of HSP70, respectively. Assessments before and after 8 weeks of treatment included glycemic endpoints, body composition, and muscular endurance, power, and perfusion. An HT mice had more than threefold, and GGA mice had a twofold greater HSP70 compared with control. Despite comparable body compositions, both treatment groups had significantly better insulin sensitivity and insulin signaling capacity. Compared with baseline, HT mice ran 23% longer than at study start, which was significantly more than GGA or control. Hanging ability (muscular endurance) also tended to be best preserved in HT mice. Muscle power, contractile force, capillary perfusion, and innervation were not different. Heat treatment has a clear benefit on muscular endurance, whereas HT and GGA both improved insulin sensitivity. Different effects may relate to muscle HSP70 levels. An HSP induction could be a promising approach for improving health span in the aged mice.
authors.affiliation: Departments of Pathology.
authors.forename: Marnie G
authors.initials: MG
authors.lastname: Silverstein
authors.affiliation: Departments of Pathology.
authors.forename: Diane
authors.initials: D
authors.lastname: Ordanes
authors.affiliation: Departments of Pathology.
authors.forename: Ashley T
authors.initials: AT
authors.lastname: Wylie
authors.affiliation: Internal Medicine-Pulmonary, Critical Care, Allergy and Immunology, and.
authors.forename: D Clark
authors.initials: DC
authors.lastname: Files
authors.affiliation: Neurobiology and Anatomy, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Carol
authors.initials: C
authors.lastname: Milligan
authors.affiliation: Department of Chemistry, Winston-Salem State University, North Carolina.
authors.forename: Tennille D
authors.initials: TD
authors.lastname: Presley
authors.affiliation: Departments of Pathology, kkavanag@wakehealth.edu.
authors.forename: Kylie
authors.initials: K
authors.lastname: Kavanagh
mesh_terms: D000818:Animals; D001823:Body Composition; D004224:Diterpenes; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000502:physiology*; D006979:Hyperthermia, Induced; D007333:Insulin Resistance / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D011897:Random Allocation
chemical_list: D004224:Diterpenes; D018840:HSP70 Heat-Shock Proteins; C031049:geranylgeranylacetone
keywords: Heat shock proteins; Heat therapy; Insulin resistance; Sarcopenia.