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基本情報 |
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氏名 |
田村 優樹 |
氏名(カナ) |
タムラ ユウキ |
氏名(英語) |
TAMURA Yuki |
Effects of heat stress on unfolded protein responses in aged skeletal muscle
The Journal of Gerontology Series A – Biological Science and Medical Science
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Mitochondrial and endoplasmic reticulum (ER) stress, and subsequently activated responses (mitochondrial/ER unfolded protein responses; UPRmt/UPRER), are involved in the pathogenesis of sarcopenia. To extend both basic and translational knowledge, we examined (i) whether age-induced mitochondrial and ER stress depend on skeletal muscle type in mice and (ii) whether heat stress treatment, a suggested strategy for sarcopenia, improves age-induced mitochondrial and ER stress. Aged (21-month-old) mice showed more severe mitochondrial stress and UPRmt than young (12-week-old) mice, based on increased oxidative stress, mitochondrial proteases, and mitochondrial E3 ubiquitin ligase. The aged mice also showed ER stress and UPRER, based on decreased ER enzymes and increased ER stress-related cell death. These changes were much more evident in soleus muscle than in gastrocnemius and plantaris muscles. After daily heat stress treatment (40 °C chamber for 30 minutes per day) for 4 weeks, mice showed remarkable improvements in age-related changes in soleus muscle. Heat stress had only minor effects in gastrocnemius and plantaris muscles. Based on these findings, age-associated mitochondrial stress, ER stress, and UPRmt/ER vary qualitatively with skeletal muscle type. Our results suggest a molecular basis for the beneficial effects of heat stress on muscle atrophy with age in soleus muscle.
Yuki Tamura, Yutaka Matsunaga, Yu Kitaoka, Hideo Hatta.
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