Acute and short-term insulin-induced molecular adaptations of GLUT2 gene expression in the renal cortex of diabetic rats

Autor(es)

Freitas, Helayne Soares ^[1] ; Schaan, Beatriz D’Agord ; Seraphim, Patricia Monteiro ; Nunes, Maria Tereza ; Machado, Ubiratan Fabres

Afiliação do(s) autor(es)

^[1] Universidade de São Paulo (USP). Instituto de Ciências Biomédicas. Departamento de Fisiologia e Biofísica - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Molecular and Cellular Endocrinology; v. 237, n. 1/2, p. 49-57, Jun. 2005.
• Área do conhecimento: Ciências Biológicas - Fisiologia
• Assunto(s): Túbulos renais proximais Nefropatias diabéticas Expressão gênica

Resumo

Increased GLUT2 gene expression in the renal proximal tubule of diabetic rats is an adaptive condition, which may be important in the diabetic nephropathy development. We investigated the effects of insulin treatment upon the renal GLUT2 overexpression of diabetic rats. Acute treatment, surprisingly, induced a rapid further increase in GLUT2 mRNA content. Twelve hours after insulin injection, GLUT2 mRNA was twice the value of saline-injected rats (P < 0.001), when GLUT2 protein remained unchanged. In response to short-term treatment, both GLUT2 mRNA and protein were increased in 1-day treated rats (P < 0.05 versus saline-injected), decreasing after that, and reaching, within 6 days, values close to those of non-diabetic rats. Concluding, insulin treatment induced: initially, an additional upregulation of GLUT2 gene expression, involving posttranscriptional modulation; thereafter, downregulation of GLUT2 expression, which returns to non-diabetic levels. The former may be related to increased insulin concentration, the latter may be due to glycemic control. (AU)

• Processo FAPESP: 02/07384-4 - Regulação da expressão gênica dos transportadores de glicose no diabetes mellitus: papel na fisiopatologia e potencialidades preventivas e terapêuticas
• Beneficiário: Ubiratan Fabres Machado
• Modalidade de apoio: Auxílio à Pesquisa - Temático