To investigate whether heat stress attenuates skeletal muscle atrophy of the extensor digitorum longus (EDL) muscle in streptozotocin-induced diabetic rats, 12-week-old male Wistar rats were randomly assigned to four groups (n = 6 per group): control (Con), heat stress (HS), diabetes mellitus (DM), and diabetes mellitus/heat stress (DM + HS). Diabetes was induced by intraperitoneal injection of streptozotocin (50 mg/kg). Heat stress was induced in the HS and DM + HS groups by immersion of the lower half of the body in hot water at 42 °C for 30 min; it was initiated 7 days after injection of streptozotocin, and was performed once a day, five times a week for 3 weeks. The muscle fiber cross-sectional area of EDL muscles from diabetic and non-diabetic rats was determined; heat stress protein (HSP) 72 and HSP25 expression levels were also analyzed by western blotting. Diabetes-induced muscle fiber atrophy was attenuated upon heat stress treatment in diabetic rats. HSP72 and HSP25 expression was upregulated in the DM + HS group compared with the DM group. Our findings suggest that heat stress attenuates atrophy of the EDL muscle by upregulating HSP72 and HSP25 expression.
Armstrong RB , Gollnick PD, Ianuzzo CD: Histochemical properties of skeletal muscle fibers in streptozotocindiabetic rats. Cell Tissue Res. 162, 387–394 (1975)
Atalay M , Oksala NK, Laaksonen DE, Khanna S, Nakao C, Lappalainen J, Roy S, Hänninen O, Sen CK: Exercise training modulates heat shock protein response in diabetic rats. J. Appl. Physiol. 97, 605–611 (2004)
Chen GQ , Mou CY, Wang S, Zhao ZW: Exercise training has beneficial anti-atrophy effects by inhibiting oxidative stress-induced MuRF1 upregulation in rats with diabetes. Life Sci. 89, 44–49 (2011)
Dean RT , Fu S, Stocker R, Davies MJ: Biochemistry and pathology of radical-mediated protein oxidation. Biochem. J. 324, 1–18 (1997)
Dodd SL , Hain B, Senf SM, Judge AR: Hsp27 inhibits IKKbeta-induced NF-kappaB activity and skeletal muscle atrophy. FASEB J. 23, 3415–3423 (2009)
Escobedo J , Pucci AM, Koh TJ: HSP25 protects skeletal muscle cells against oxidative stress. Free Radic. Biol. Med. 37, 1455–1462 (2004)
Leenders M , Verdijk LB, van der Hoeven L, Adam JJ, van Kranenburg J, Nilwik R, van Loon LJ: Patients with type 2 diabetes show a greater decline in muscle mass, muscle strength, and functional capacity with aging. J. Am. Med. Dir. Assoc. 14, 585–592 (2013)
Macgilchrist C , Paul L, Ellis BM, Howe TE, Kennon B, Godwin J: Lower-limb risk factors for falls in people with diabetes mellitus. Diabet. Med. 27, 162–168 (2010)
Maurer MS , Burcham J, Cheng H: Diabetes mellitus is associated with an increased risk of falls in elderly residents of a long-term care facility. J. Gerontol. A Biol. Sci. Med. Sci. 60, 1157–1162 (2005)
Najemnikova E , Rodgers CD, Locke M: Altered heat stress response following streptozotocin-induced diabetes. Cell Stress Chaperon. 12, 342–352 (2007)
Nonaka K , Une S, Tatsuta N, Ito K, Akiyama J: Changes in antioxidant enzymes and lipid peroxidation in extensor digitorum longus muscles of streptozotocin-diabetic rats may contribute to muscle atrophy. Acta Physiol. Hung. 101, 421–428 (2014)
Ogata T , Oishi Y, Higashida K, Higuchi M, Muraoka I: Prolonged exercise training induces long-term enhancement of HSP70 expression in rat plantaris muscle. Am. J. Physiol. Regul. Integr. Comp. Physiol. 296, R1557–R1563 (2009)
Oishi Y , Hayashida M, Tsukiashi S, Taniguchi K, Kami K, Roy RR, Ohira Y: Heat stress increases myonuclear number and fiber size via satellite cell activation in rat regenerating soleus fibers. J. Appl. Physiol. 107, 1612–1621 (2009)
Oishi Y , Taniguchi K, Matsumoto H, Ishihara A, Ohira Y, Roy RR: Differential responses of HSPs to heat stress in slow and fast regions of rat gastrocnemius muscle. Muscle Nerve. 28, 587–594 (2003)
Oishi Y , Taniguchi K, Matsumoto H, Ishihara A, Ohira Y, Roy RR: Muscle type-specific response of HSP60, HSP72, and HSC73 during recovery after elevation of muscle temperature. J. Appl. Physiol. 92, 1097–1103 (2002)
Patel S , Hyer S, Tweed K, Kerry S, Allan K, Rodin A, Barron J: Risk factors for fractures and falls in older women with type 2 diabetes mellitus. Calcif. Tissue Int. 82, 87–91 (2008)
Selsby JT , Dodd SL: Heat stress reduces oxidative stress and protects muscle mass during immobilization. Am. J. Physiol. Regul. Integr. Comp. Physiol. 289, R134–R139 (2005)
Senf SM , Dodd SL, McClung JM, Judge AR: Hsp70 overexpression inhibits NF-kappaB and Foxo3a transcriptional activities and prevents skeletal muscle atrophy. FASEB J. 22, 3836–3845 (2008)
Severinsen K , Obel A, Jakobsen J, Andersen H: Atrophy of foot muscles in diabetic patients can be detected with ultrasonography. Diabetes Care. 30, 3053–3057 (2007)