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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Insulin treatment reverses the increase in atrogin-1 expression in atrophied skeletal muscles of diabetic rats with acute joint inflammation

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Pinheiro-Dardis, Clara Maria [1] ; Gutierres, Vania Ortega [1] ; Assis, Renata Pires [1] ; Peviani, Sabrina Messa [2] ; Delfino, Gabriel Borges [2] ; Quagliotti Durigan, Joao Luiz [3] ; Salvini, Tania de Fatima [2] ; Baviera, Amanda Martins [1] ; Brunetti, Iguatemy Lourenco [1]
Total Authors: 9
[1] Sao Paulo State Univ UNESP, Sch Pharmaceut Sci, Dept Clin Anal, Araraquara, SP - Brazil
[2] Fed Univ Sao Carlos UFSCar, Dept Phys Therapy, Sao Carlos, SP - Brazil
[3] Univ Brasilia, Phys Therapy Div, Brasilia, DF - Brazil
Total Affiliations: 3
Document type: Journal article
Web of Science Citations: 1

Background: The aim of this study was to evaluate the changes in biomarkers of skeletal muscle proteolysis (atrogin-1, muscle RING finger-1 protein {[}MuRF-1]) and inflammation (nuclear factor kappa-B) in skeletal muscles of rats under two catabolic conditions, diabetes mellitus (DM) and acute joint inflammation, and the effects of insulin therapy. Materials and methods: Male Wistar rats were divided into groups without diabetes - normal (N), saline (NS), or iota-carrageenan (NCa) injection into the tibiotarsal joint - and groups with diabetes - diabetes (D), plus insulin (DI), saline (DS), or iota-carrageenan (DCa) injection into the tibiotarsal joint, or iota-carrageenan injection and treatment with insulin (DCaI). Three days after iota-carrageenan injection (17 days after diabetes induction), tibialis anterior (TA) and soleus (SO) skeletal muscles were used for analysis. Results: DM alone caused a significant decrease in the mass of TA and SO muscles, even with low levels of atrogenes (atrogin-1, MuRF-1), which could be interpreted as an adaptive mechanism to spare muscle proteins under this catabolic condition. The loss of muscle mass was exacerbated when iota-carrageenan was administered in the joints of diabetic rats, in association with increased expression of atrogin-1, MuRF-1, and nuclear factor kappa-B. Treatment with insulin prevented the increase in atrogin-1 (TA, SO) and the loss of muscle mass (SO) in diabetic-carrageenan rats; in comparison with TA, SO muscle was more responsive to the anabolic actions of insulin. Conclusion: Acute joint inflammation overcame the adaptive mechanism in diabetic rats to prevent excessive loss of muscle mass, worsening the catabolic state. The treatment of diabetic-carrageenan rats with insulin prevented the loss of skeletal muscle mass mainly via atrogin-1 inhibition. Under the condition of DM and inflammation, muscles with the prevalence of slow-twitch, type 1 fibers were more responsive to insulin treatment, recovering the ability to grow. (AU)

FAPESP's process: 10/00892-0 - Effect of acute ankle inflammation on histological features, gene expression and levels of creatine kinase and antioxidant enzymes in the soleus and anterior tibialis muscles of diabetic rats
Grantee:Iguatemy Lourenço Brunetti
Support Opportunities: Regular Research Grants