par Kefas, Benjamin Ate;Cai, Ying
;Ling, Zhidong;Heimberg, Harry;Hue, Louis;Pipeleers, Daniel;Van De Casteele, Christine 
Référence Journal of molecular endocrinology, 30, 2, page (151-161)
Publication Publié, 2003-04


Référence Journal of molecular endocrinology, 30, 2, page (151-161)
Publication Publié, 2003-04
Article révisé par les pairs
Résumé : | We have recently shown that conditions known to activate AMP-activated protein kinase (AMPK) in primary β-cells can trigger their apoptosis. The present study demonstrates that this is also the case in the MIN6 β-cell line, which was used to investigate the underlying mechanism. Sustained activation of AMPK was induced by culture with the adenosine analogue AICA-riboside or at low glucose concentrations. Both conditions induced a sequential activation of AMPK, c-Jun-N-terminal kinase (JNK) and caspase-3. The effects of AMPK on JNK activation and apoptosis were demonstrated by adenoviral expression of constitutively active AMPK, a condition which reproduced the earlier-described AMPK-dependent effects on pyruvate kinase and acetyl-coA-carboxylase. The effects of JNK activation on apoptosis were demonstrated by the observations that (i) its inhibition by dicumarol prevented caspase-3 activation and apoptosis, (ii) adenoviral expression of the JNK-interacting scaffold protein JIP-1/IB-1 increased AICA-riboside-induced JNK activation and apoptosis. In primary β-cells, AMPK activation was also found to activate JNK, involving primarily the JNK 2 (p54) isoform. It is concluded that prolonged stimulation of AMPK can induce apoptosis of insulin-producing cells through an activation pathway that involves JNK, and subsequently, caspase-3. |