• Citer

Cytokines tumor necrosis factor-alpha and interferon-gamma induce pancreatic beta-cell apoptosis through STAT1-mediated Bim protein activation.

par Barthson, Jenny ;Germano, Carla Maria Ramos C.M.;Moore, Fabrice ;Maida, Adriano;Drucker, Daniel J;Marchetti, Piero;Gysemans, Conny;Mathieu, Chantal;Nuñez, Gabriel;Jurisicova, Andrea;Eizirik, Decio L. ;Gurzov, Esteban Nicolas
Référence The Journal of biological chemistry, 286, 45, page (39632-39643)
Publication Publié, 2011

Article révisé par les pairs

• Accès en ligne
• Détails
• Contenu
• Statistiques

Résumé :

Type 1 diabetes is characterized by local inflammation (insulitis) in the pancreatic islets causing β-cell loss. The mitochondrial pathway of apoptosis is regulated by the balance and interaction between Bcl-2 members. Here we clarify the molecular mechanism of β-cell death triggered by the pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interferon (IFN)-γ. The combination of TNF-α + IFN-γ induced DP5, p53 up-regulated modulator of apoptosis (PUMA), and Bim expression in human islets and rodent β-cells. DP5 and PUMA inactivation by RNA interference partially protected against TNF-α + IFN-γ-induced β-cell apoptosis. DP5 knock-out mice had increased β-cell area, and isolated islets from these mice were resistant to cytokine exposure. Bim expression was transcriptionally regulated by STAT1, and its activation triggered cleavage of caspases. Silencing of Bim protected rodent and human β-cells to a large extent against TNF-α + IFN-γ, indicating a major role of this BH3-only activator protein in the mechanism of apoptosis. Our data support a highly regulated and context-dependent modulation of specific Bcl-2 members controlling the mitochondrial pathway of β-cell apoptosis during insulitis.