title: Age related obesity-induced shortening of GLUT4 mRNA poly(A) tail length in rat gastrocnemius skeletal muscle.
abstract: Obese insulin resistant animals and humans have shown reduced GLUT4 gene expression. Yet, in skeletal muscle, discrepancy between mRNA and protein regulation has been frequently observed, suggesting a post-transcriptional modulation. We investigated the GLUT4 expression in adipose tissue and muscle of obese 12-month-old (12-mo) rats, comparing with lean 2-month-old (2-mo) animals. Obesity was accompanied by insulin resistance, and 65% reduction (P<0.01) in GLUT4 mRNA and protein in adipose tissue. However, in muscle, despite increased (P<0.05) mRNA content, GLUT4 protein was unchanged. RNase H and poly(A) test assays showed a reduction (P<0.01) of approximately 80 adenines in the GLUT4 mRNA poly(A) tail of muscle from 12-mo rats, recognizing that the poly(A) tail length correlates with translation efficiency. Concluding, age related obesity of 12-mo rats involves suppression of GLUT4 expression in adipose tissue; however, in muscle, GLUT4 mRNA content increases, but with a shorter poly(A) tail, thus unchanging the protein content.
authors: Department of Physiotherapy, University of State of Sao Paulo, Presidente Prudente, Sao Paulo, Brazil.
authors: Patricia Monteiro
authors: PM
authors: Seraphim
authors: Maria Tereza
authors: MT
authors: Nunes
authors: Gisele
authors: G
authors: Giannocco
authors: Ubiratan Fabres
authors: UF
authors: Machado
mesh_terms: D000225:Adenine; D052436:Adipose Tissue, White / Q000378:metabolism; D000375:Aging; D000818:Animals; D005786:Gene Expression Regulation; D051275:Glucose Transporter Type 4 / Q000235:genetics* / Q000378:metabolism; D007333:Insulin Resistance; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D009765:Obesity / Q000235:genetics* / Q000473:pathology; D011061:Poly A / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D051275:Glucose Transporter Type 4; D012333:RNA, Messenger; D011061:Poly A; D000225:Adenine