Journals of Gerontology: BIOLOGICAL SCIENCES Cite journal as: J Gerontol A Biol Sci Med Sci doi:10.1093/gerona/glu015

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Muscle Heat Shock Protein 70 Predicts Insulin Resistance With Aging Lee Chichester,1 Ashley T. Wylie,1 Suzanne Craft,2 and Kylie Kavanagh1 1 Departments of Pathology and Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina.


Address correspondence to Kylie Kavanagh, DVM, MS, MPH, Department of Pathology, Section on Comparative Medicine and Lipid Sciences, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27127. Email: [email protected]

Key Words:  Heat shock protein 70—Insulin sensitivity—Aging—Monkey. Received November 13, 2013; Accepted January 16, 2014 Decision Editor: Rafael de Cabo, PhD


he cytoplasmic chaperone, heat shock protein 70 (HSP70), has a fundamental role in maintenance of cellular homeostasis through its chaperone actions (1).One of the hypotheses of cellular aging is the accumulation of oxidation damage or mishandling of cellular components in which the chaperone system is critically important (2). Inadequacy of chaperone capacity can both lead to, and result from, endoplasmic reticular stress that leads to activation of c-jun N-terminal kinases and serine phosphorylation of insulin receptor substrates with reduced efficacy of insulin signaling. As such, the development of insulin resistance with aging has been considered a normal process (3–6). Genetic modification of both the insulin sensitivity and chaperone protein systems has resulted in improved longevity in rodent and invertebrate research models (7,8). Augmenting HSP70 has been shown to improve insulin sensitivity in mice, monkeys, and people (9–11). Further tissue levels of HSP70 positively associate with life span across a wide range of vertebrate species (12) but understanding how inherent HSP70 levels affect future health span and life span is currently unknown. It is known that HSP70 is a highly heritable trait in monkeys (13) and that similar HSP70 levels are observed in human siblings despite discordant metabolic status (14). Extreme longevity in people is also heritable (15,16) and is consistently observed

with preserved insulin sensitivity (17,18). We hypothesized that inherent HSP70 levels in tissues may contribute to the individual’s potential for maintaining insulin sensitivity and thus contribute to their health span and by extension, perhaps life span. The aim of the current study was to understand whether HSP70 is a proximal risk factor in the development of insulin resistance and type 2 diabetes (T2DM) and how tissue and plasma HSP70 change with aging. This would extend our prior findings that increasing HSP70 can improve insulin sensitivity in monkeys (10) and that HSP70 is reduced in tissues of diabetic and insulin resistant monkeys (13,19). Such prospective studies evaluating insulin resistance development are difficult to achieve in clinical situations with variability in environmental influences, and so an aging nonhuman primate model allows investigations regarding healthy aging on a compressed timescale. Methods Participants Animals.—Forty-one female African green monkeys (Chlorocebus aethiops; Table  1) ranging in age from 7 to 18 years at study start (maximum life span ≈ 25 years) Page 1 of 8

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Heat shock protein 70 (HSP70) protects cells from accumulating damaged proteins and age-related functional decline. We studied plasma and skeletal muscle (SkM) HSP70 levels in adult vervet monkeys (life span ≈ 25 years) at baseline and after 4 years (≈10 human years). Insulin, glucose, homeostasis model assessment scores, triglycerides, high-density lipoprotein and total plasma cholesterol, body weight, body mass index, and waist circumference were measured repeatedly, with change over time estimated by individual regression slopes. Low baseline SkM HSP70 was a proximal marker for developing insulin resistance and was seen in monkeys whose insulin and homeostasis model assessment increased more rapidly over time. Changes in SkM HSP70 inversely correlated with insulin and homeostasis model assessment trajectories such that a positive change in SkM level was beneficial. The strength of the relationship between changes in SkM HSP70 and insulin remained unchanged after adjustment for all covariates. Younger monkeys drove these relationships, with HSP70 alone being predictive of insulin changes with aging. Plasma and SkM HSP70 were unrelated and HSP70 release from peripheral blood mononuclear cells was positively associated with insulin concentrations in contrast to SkM. Results from aged humans confirmed this positive association of plasma HSP70 and insulin. In conclusion, higher levels of SkM HSP70 protect against insulin resistance development during healthy aging.

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Humans.—Fifteen elderly human participants (Table 2), eight male and seven female, ranging in age from 56 to Table 1.  Mean (±SEM) Baseline Metabolic and Morphometric Characteristics of the Monkeys Observed Over the 4-Year Experimental Period

N Age (y) Body weight (kg) BMI (kg/m2) Waist circumference (cm) Glucose (mg/dL) Insulin (U/L) HOMA (AU) TG (mg/dL) TPC (mg/dL) HDL-C (mg/dL) SBP (mmHg) DBP (mmHg)



p Value ANOVA

24 8.8 (0.23) 5.4 (0.14) 26 (0.57) 34 (0.68) 56 (2.1) 13 (4.4) 2.2 (0.93) 33 (1.6) 134 (3.3) 79 (2.7) 121 (3.8) 68 (1.8)

17 15 (0.45) 5.0 (0.13) 26 (0.65) 34 (0.97) 68 (6.3) 18 (5.8) 4.0 (1.7) 41 (4.2) 143 (5.5) 82 (3.6) 125 (4.4) 68 (2.4)

1,000% difference). Female vervets enter menopause only in their terminal years, and so insulin sensitivity changes coincident with the menopausal change were unlikely (50). We acknowledge that a healthy participant selection bias may exist in the older monkeys, as diabetic and disabled monkeys are removed from the breeding colony. We feel this was a strength of the study design, as diabetes is known to further suppress HSP70 levels in tissues (10,13,19), and so we can be confident that our associations with insulin across time were not driven by the development of these diabetic phenotypes. In conclusion, we were able to show prospectively that elevated SkM HSP70 is protective against insulin resistance and these protective effects were most prominent in younger animals. Plasma HSP70 levels were not associated with a metabolic phenotype, but did rise over the significant duration of the study period, and release by PBMNCs was increased in hyperinsulinemic states. Similar relationships between HSP70 and insulin levels were seen in human patients. Based on patterns of observed insulin changes, interventions to increase tissue HSP70 and optimize health span may be more effective if introduced before becoming geriatric. This study shows that SkM HSP70 levels play an important role determining insulin sensitivity preservation with healthy aging.

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39. Garcia JJ, Martin-Cordero L, Hinchado MD, Bote ME, Ortega E. Effects of habitual exercise on the eHsp72-induced release of inflammatory cytokines by macrophages from obese Zucker rats. Int J Sports Med. 2013;34:559–564. doi:10.1055/s-0032-1327650 40. Njemini R, Bautmans I, Onyema OO, Van Puyvelde K, Demanet C, Mets T. Circulating heat shock protein 70 in health, aging and disease. BMC Immunol. 2011;12:24. doi:10.1186/1471-2172-12-24 41. Nakhjavani M, Morteza A, Khajeali L, et al. Increased serum HSP70 levels are associated with the duration of diabetes. Cell Stress Chaperones. 2010;15:959–964. doi:10.1007/s12192-010-0204-z 42. Terry DF, Wyszynski DF, Nolan VG, et al. Serum heat shock protein 70 level as a biomarker of exceptional longevity. Mech Ageing Dev. 2006;127:862–868. doi:10.1016/j.mad.2006.08.007 43. Vega VL, Charles W, Crotty Alexander LE, Alexander LE. Rescuing of deficient killing and phagocytic activities of macrophages derived from non-obese diabetic mice by treatment with geldanamycin or heat shock: potential clinical implications. Cell Stress Chaperones. 2011;16:573–581. doi:10.1007/s12192-011-0268-4 44. Pennathur S, Heinecke JW. Mechanisms for oxidative stress in diabetic cardiovascular disease. Antioxid Redox Signal. 2007;9:955– 969. doi:10.1089/ars.2007.1595 45. Njemini R, Lambert M, Demanet C, Kooijman R, Mets T. Basal and infection-induced levels of heat shock proteins in human aging. Biogerontology. 2007;8:353–364. doi:10.1007/s10522-006-9078-y 46. Rea IM, McNerlan S, Pockley AG. Serum heat shock protein and anti-heat shock protein antibody levels in aging. Exp Gerontol. 2001;36:341–352. doi:S0531-5565(00)00215-1 [pii] 47. Lane MA. Nonhuman primate models in biogerontology. Exp Gerontol. 2000;35:533–541. doi:S0531-5565(00)00102-9 [pii] 48. Nadon NL. Of mice and monkeys: National Institute on Aging resources supporting the use of animal models in biogerontology research. J Gerontol A  Biol Sci Med Sci. 2006;61:813–815. doi:61/8/813[pii] 49. Yeung EH, Zhang C, Mumford SL, et al. Longitudinal study of insulin resistance and sex hormones over the menstrual cycle: the BioCycle Study. J Clin Endocrinol Metab. 2010;95:5435–5442. doi:10.1210/ jc.2010-0702 50. Walker ML, Herndon JG. Menopause in nonhuman primates? Biol Reprod. 2008;79:398–406. doi:10.1095/biolreprod.108.068536

Downloaded from at Umea universitet on August 20, 2014

28. Yokoyama K, Fukumoto K, Murakami T, et  al. Extended lon gevity of Caenorhabditis elegans by knocking in extra copies of hsp70F, a homolog of mot-2 (mortalin)/mthsp70/Grp75. FEBS Lett. 2002;516:53–57. doi:S0014579302024705 [pii] 29. Bruce CR, Carey AL, Hawley JA, Febbraio MA. Intramuscular heat shock protein 72 and heme oxygenase-1 mRNA are reduced in patients with type 2 diabetes: evidence that insulin resistance is associated with a disturbed antioxidant defense mechanism. Diabetes. 2003;52:2338–2345. 30. Heydari AR, You S, Takahashi R, Gutsmann A, Sarge KD, Richardson A. Effect of caloric restriction on the expression of heat shock protein 70 and the activation of heat shock transcription factor 1. Dev Genet. 1996;18:114–124. doi:10.1002/ (SICI)1520-6408(1996)18:23.0.CO;2-C[pii] 31. Terry DF, McCormick M, Andersen S, et al. Cardiovascular disease delay in centenarian offspring: role of heat shock proteins. Ann N Y Acad Sci. 2004;1019:502–505. doi:10.1196/annals.1297.0921019/1/502 [pii] 32. Chiang WC, Ching TT, Lee HC, Mousigian C, Hsu AL. HSF-1 regulators DDL-1/2 link insulin-like signaling to heat-shock responses and modulation of longevity. Cell. 2012;148:322–334. doi:10.1016/j. cell.2011.12.019 33. Hsu AL, Murphy CT, Kenyon C. Regulation of aging and age-related disease by DAF-16 and heat-shock factor. Science. 2003;300:1142– 1145. doi:10.1126/science.1083701300/5622/1142 [pii] 34. Lithgow GJ, White TM, Melov S, Johnson TE. Thermotolerance and extended life-span conferred by single-gene mutations and induced by thermal stress. Proc Natl Acad Sci U S A. 1995;92:7540–7544. 35. Saunders LR, Verdin E. Cell biology. Stress response and aging. Science. 2009;323:1021–1022. doi:10.1126/science.1170007 36. Asea A, Rehli M, Kabingu E, et al. Novel signal transduction pathway utilized by extracellular HSP70: role of toll-like receptor (TLR) 2 and TLR4. J Biol Chem. 2002;277:15028–15034. doi:10.1074/jbc. M200497200 37. Asea A. Mechanisms of HSP72 release. J Biosci. 2007;32:579–584. 38. Asea A, Kraeft SK, Kurt-Jones EA, et al. HSP70 stimulates cytokine production through a CD14-dependant pathway, demonstrating its dual role as a chaperone and cytokine. Nat Med. 2000;6:435–442. doi:10.1038/74697.

Muscle heat shock protein 70 predicts insulin resistance with aging.

Heat shock protein 70 (HSP70) protects cells from accumulating damaged proteins and age-related functional decline. We studied plasma and skeletal mus...
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