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Evidence for the involvement of cGMP and protein kinase G in nitric oxide‐induced apoptosis in the pancreatic B‐cell line, HIT‐T15
Author(s) -
Loweth Anne C,
Williams Gwyn T,
Scarpello John H.B,
Morgan Noel G
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(96)01392-0
Subject(s) - nitric oxide , apoptosis , cell culture , chemistry , kinase , cgmp dependent protein kinase , line (geometry) , protein kinase a , microbiology and biotechnology , biochemistry , medicine , mitogen activated protein kinase kinase , biology , genetics , geometry , mathematics
Intracellular production of nitric oxide (NO) is thought to mediate the pancreatic B‐cell‐directed cytotoxicity of cytokines in insulin‐dependent diabetes mellitus, and recent evidence has indicated that this may involve induction of apoptosis. A primary effect of NO is to activate soluble guanylyl cyclase leading to increased cGMP levels and this effect has been demonstrated in pancreatic B‐cells, although no intracellular function has been defined for islet cGMP. Here we demonstrate that the NO donor, GSNO, induces apoptosis in the pancreatic B‐cell line HIT‐T15 in a dose‐ and time‐dependent manner. This response was significantly attenuated by micromolar concentrations of a specific inhibitor of soluble guanylyl cyclase, ODQ, and both 8‐bromo cGMP (100 μM) and dibutyryl cGMP (300 μM) were able to fully relieve this inhibition. In addition, incubation of HIT‐T15 cells with each cGMP analogue directly promoted cell death in the absence of ODQ. KT5823, a potent and highly selective inhibitor of cGMP‐dependent protein kinase (PKG), abolished the induction of cell death in HIT cells in response to either GSNO or cGMP analogues. This effect was dose‐dependent over the concentration range of 10–250 nM. Overall, these data provide evidence that the activation of apoptosis in HIT‐T15 cells by NO donors is secondary to a rise in cGMP and suggest that the pathway controlling cell death involves activation of PKG.