Increased Skeletal Muscle GLUT4 Expression in Obese Mice After Voluntary Wheel Running Exercise Is Posttranscriptional

Exercise promotes glucose clearance by increasing skeletal muscle GLUT4-mediated glucose uptake. Importantly, exercise upregulates muscle GLUT4 expression in an insulin-independent manner under conditions of insulin resistance, such as with type 2 diabetes. However, the insulin-independent mechanism responsible for rescued muscle GLUT4 expression is poorly understood. We used voluntary wheel running (VWR) in mice to test the prevailing hypothesis that insulin-independent upregulation of skeletal muscle GLUT4 protein expression with exercise is through increased Glut4 transcription. We demonstrate that 4 weeks of VWR exercise in obese mice rescued high-fat diet–induced decreased muscle GLUT4 protein and improved both fasting plasma insulin and hepatic triacylglyceride levels, but did not rescue muscle Glut4 mRNA. Persistent reduction in Glut4 mRNA suggests that a posttranscriptional mechanism regulated insulin-independent muscle GLUT4 protein expression in response to exercise in lean and obese mice. Reduction of GLUT4 protein in sedentary animals upon treatment with rapamycin revealed mTORC1-dependent GLUT4 regulation. However, no difference in GLUT4 protein expression was observed in VWR-exercised mice treated with either rapamycin or Torin 1, indicating that exercise-dependent regulation on GLUT4 was mTOR independent. The findings provide new insight into the mechanisms responsible for exercise-dependent regulation of GLUT4 in muscle.

Diabetes Metabolism


Increased Skeletal Muscle GLUT4 Expression in Obese Mice After Voluntary Wheel Running Exercise Is Posttranscriptional was first posted on January 6, 2017 at 4:18 pm.
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Reblogged 4 months ago from diabeticscareguide.com

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Amrita Wellness Medicine Clinic

Alina Porojan has been working as a natural medicine practitioner for the past twelve years, constantly educating herself and deepening her knowledge and clinical experience. Alina believes that health and healing is inherent to each of us, and sees her role as re-connecting us to our already existing potential for optimal health and wellness.