Inhibition of Nuclear Factor-kappa B or Bax Prevents Endoplasmic Reticulum Stress-But Not Nitric Oxide-Mediated Apoptosis in INS-1E Cells

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Accumulating evidence suggests that endoplasmic reticulum ( ER) stress by mechanisms that include ER Ca2+ depletion via NO-dependent down-regulation of sarcoendoplasmic reticulum Ca2+ ATPase 2b (SERCA2b) contributes to beta-cell death in type 1 diabetes. To clarify whether the molecular pathways elicited by NO and ER Ca2+ depletion differ, we here compare the direct effects of NO, in the form of the NO donor S-nitroso-N-acetyl-D, L-penicillamine (SNAP), with the effects of SERCA2 inhibitor thapsigargin (TG) on MAPK, nuclear factor kappa B (NF kappa B), Bcl-2 proteins, ER stress, and apoptosis. Exposure of INS-1E cells to TG or SNAP caused caspase-3 cleavage and apoptosis. Both TG and SNAP induced activation of the proapoptotic transcription factor CCAAT/enhancer-binding protein homologous protein (CHOP). However, other classical ER stress-induced markers such as up-regulation of ER chaperone Bip and alternative splicing of the transcription factor Xbp-1 were exclusively activated by TG. TG exposure caused NF kappa B activation, as assessed by I kappa B degradation and NF kappa B DNA binding. Inhibition of NF kappa B or the Bcl-2 family member Bax pathways protected beta-cells against TG- but not SNAP-induced beta-cell death. These data suggest that NO generation and direct SERCA2 inhibition cause two quantitative and qualitative different forms of ER stress. In contrast to NO, direct ER stress induced by SERCA inhibition causes activation of ER stress signaling pathways and elicit proapoptotic signaling via NF kappa B and Bax. (Endocrinology 150: 4094-4103, 2009)
Udgivelsesdato: 2009/9
Udgave nummer9
Sider (fra-til)4094-4103
Antal sider9
StatusUdgivet - 2009

Bibliografisk note

Times Cited: 0ArticleEnglishMandrup-Poulsen, THagedorn Res Inst, Niels Steensens Vej 1,NLE-2-17-1, DK-2820 Gentofte, DenmarkCited References Count: 59485XVENDOCRINE SOC8401 CONNECTICUT AVE, SUITE 900, CHEVY CHASE, MD 20815-5817 USACHEVY CHASE

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