Diabetes abolishes the \'\'in vitro\'\' muscle contraction-induced increase in SLC2A4 gene expression. Participation of AMPK and CAMKII kinases and MEF2D, GEF, HIF-1a and TRa1 transcriptional factors.

Author(s)

Guilherme Alves de Lima

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2011-08-18

Examining board members

Ubiratan Fabres Machado; Gabriel Forato Anhê; Karla Fabiana Santana de Melo Cabral Fagundes; Maria Lucia Cardillo Correa Giannella; Beatriz D'Agord Schaan

• Advisor: Ubiratan Fabres Machado

Abstract

The SLC2A4 gene encodes the GLUT4 protein, which is essential in glucose homeostasis. OBJECTIVE: To investigate the diabetes effect on muscle contraction-induced in SLC2A4 gene expression. METHODS: Soleus muscles of Non diabetic rats (ND) and diabetic treated with insulin (DI) or saline (DS) were incubated and contracted. The GLUT4, pAMPK and CAMKII expressions were analyzed by PCR and Western blotting, and the MEF2D, GEF, HIF-1<font face=\"Symbol\">a and TR<font face=\"Symbol\">a1 activity by gel shift. C2C12 cells transfected with plasmids containing the binding sites for MEF2, HIF, and TR were treated with AICAR or caffeine. RESULTS: Contraction increased the GLUT4 amount in animals ND and DI, but not in DS. In ND animals, contraction increased AMPK, MEF2D, GEF and TR<font face=\"Symbol\">a1 activity, but not in DS. In ND animals, AMPK and CAMKII inhibitors abolished the GLUT4 increase as like MEF2D and GEF activity. In C2C12 cells AMPK and caffeine activated the 3 sites. CONCLUSION: Diabetes abolishes the muscle contraction-induced GLUT4 increase due to reduced of MEF2D, GEF, TR<font face=\"Symbol\">a1 and AMPK activity. (AU)