title: Aging does not reduce heat shock protein 70 in the absence of chronic insulin resistance.
abstract: Heat shock protein (HSP)70 decreases with age. Often aging is associated with coincident insulin resistance and higher blood glucose levels, which also associate with lower HSP70. We aimed to understand how these factors interrelate through a series of experiments using vervet monkeys (Chlorocebus aethiops sabaeous). Monkeys (n = 284, 4-25 years) fed low-fat diets showed no association of muscle HSP70 with age (r = .04, p = .53), but levels were highly heritable. Insulin resistance was induced in vervet monkeys with high-fat diets, and muscle biopsies were taken after 0.3 or 6 years. HSP70 levels were significantly greater after 0.3 years (+72%, p < .05) but were significantly lower following 6 years of high-fat diet (-77%, p < .05). Associations with glucose also switched from being positive (r = .44, p = .03) to strikingly negative (r = -.84, p < .001) with increasing insulin resistance. In conclusion, a low-fat diet may preserve tissue HSP70 and health with aging, whereas high-fat diets, insulin resistance, and genetic factors may be more important than age for determining HSP70 levels.
authors.affiliation: Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA. kkavanag@wakehealth.edu
authors.forename: Kylie
authors.initials: K
authors.lastname: Kavanagh
authors.forename: Ashley T
authors.initials: AT
authors.lastname: Wylie
authors.forename: Tara J
authors.initials: TJ
authors.lastname: Chavanne
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Jorgensen
authors.forename: V Saroja
authors.initials: VS
authors.lastname: Voruganti
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Comuzzie
authors.forename: Jay R
authors.initials: JR
authors.lastname: Kaplan
authors.forename: Charles E
authors.initials: CE
authors.lastname: McCall
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
mesh_terms: D000375:Aging / Q000097:blood / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002522:Chlorocebus aethiops; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D059305:Diet, High-Fat; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology; D008055:Lipids / Q000097:blood; D018482:Muscle, Skeletal / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D002791:Cholesterol, Dietary; D018840:HSP70 Heat-Shock Proteins; D008055:Lipids