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Diabetes‐derived muscle atrophy is associated with cellular autophagy, and potential beneficial effects of interventional physical exercise on it
Author(s) -
Lee Youngjeon,
Won Jinyoung,
Kang Jae seon,
Hong Yonggeun
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.930.5
Subject(s) - autophagy , muscle atrophy , skeletal muscle , medicine , endocrinology , atrophy , sarcopenia , diabetes mellitus , gastrocnemius muscle , oxidative stress , chemistry , apoptosis , biochemistry
Diabetes accompanied with cellular stress, such as functional decrease of glucose uptake, hyperglycemic oxidative stress, and damaged mitochondria. Muscle atrophy occurs when the degradation rate is higher than the synthesis rate during diabetes. Here, we hypothesized that diabetes induces skeletal muscle autophagy, however, if this increased autophagy becomes chronic, autophagy‐mediated cell death occurs that could then contribute to skeletal muscle cell loss. Sprague‐Dawley rats were injected with STZ(60 mg/kg of body weight) and after 30 days, the soleus(SOL), plantaris(PL), red gastrocnemius(RG), and white gastrocnemius(WG) muscles were assessed by immunohistochemical and western blot analysis. LC3 expression, as an autophagosomal marker was detected in all muscles examined, but was reduced in RG muscles. The content of both beclin‐1 and caspase were elevated in WG and PL muscles. All muscles from diabetic animals demonstrated reduced mass when compared to controls, but only the gastrocnemius demonstrated atrophy as reflected by a reduced muscle‐to‐body mass ratio. In addition, a group of diabetic rats submitted to daily swimming for 4 wks were compared with sedentary controls, resulting in reducing autophagy in muscles. In conclusion, these results indicate that diabetes may alter autophagic activity in a muscle‐specific manner and therapeutic exercise may modify or reverse skeletal muscle abnormalities with reducing autophagy. Keywords: Autophagy, diabetes, skeletal muscle, atrophy, LC3. Supported by KRF‐E00344, BioGreen 21 Program (#20070401034006) from Rural Development Administration, South Korea.