Reduced AMPK2 protein expression restores glucose-induced insulin secretion in islets from calorie-restricted rats

Autor(es)

Amaral, Maria Esmeria C. ^[1] ; Ribeiro, Rosane A. ^[2] ; Vanzela, Emerielle C. ^[3] ; Barbosa-Sampaio, Helena C. ^[3]

Afiliação do(s) autor(es)

^[1] UNIARARAS, Ctr Univ Herminio Ometto, Programa Posgrad Ciencias Biomed, Ave Dr Maximiliano Barutto, 500 Jd Univ Araras, BR-13607339 Araras, SP - Brazil

^[2] Univ Fed Rio de Janeiro, Campus UFRJ Macae, Macae, RJ - Brazil

^[3] Univ Estadual Campinas, UNICAMP, Inst Biol, Dept Biol Estrutural & Func, Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: International Journal of Experimental Pathology; v. 97, n. 1, p. 50-55, FEB 2016.
• Citações Web of Science: 3

Resumo

In a state of caloric restriction (CR), improved insulin action was associated with the activation of AMP-activated kinase (AMPK). Here, we verified whether AMPK was involved in impaired -cell function in islets from rats subjected to CR for 21days. Eight-week-old male rats were distributed into a control (CTL) group that was fed an isocaloric diet adlibitum or a CR group that received 60% of the food consumed by the CTL group. From days 18-21, CTL and CR rats were treated with sense (CTLS and CRS) or antisense (CTLAS and CRAS) AMPK2 oligonucleotides. Caloric restriction was associated with decreased body weight, perigonadal fat pads and insulinaemia, while higher glucose tolerance was observed in CRS rats. Antisense treatment normalized insulinaemia and glucose tolerance in CRAS rats and increased cholesterolaemia in CRAS and CTLAS groups. These effects were associated with reduced pAMPK/AMPK protein expression in the liver of rats treated with antisense oligonucleotides. Additionally, CRS islets showed higher pAMPK/AMPK content and lower glucose-induced insulin release. As expected, antisense oligonucleotides against AMPK2 efficiently reduced pAMPK/AMPK protein in CRAS and CTLAS islets. The lower AMPK content in CRAS islets normalized the insulin secretion in islets exposed to 16.7mM glucose. In addition, CTLAS islets presented higher insulin secretion at 2.8 and 16.7mM glucose. These findings support the hypothesis that higher AMPK protein expression is involved in impaired -cell function in islets from rats subjected to CR for 21days. (AU)

• Processo FAPESP: 07/08405-9 - Efeito da restrição calórica na regulação do Sirt 1, Sirt 4 e AMPK sobre a função secretória da célula beta pancreática in vivo e in vitro
• Beneficiário: Maria Esméria Corezola do Amaral
• Modalidade de apoio: Auxílio à Pesquisa - Regular