Interleukin (IL)-1β toxicity to islet β cells:: Efaroxan exerts a complete protection
Interleukin (IL)-1β toxicity to islet β cells:: Efaroxan exerts a complete protection
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DOI：
10.1002/jcp.20198
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发表时间：
2005-04-01
影响因子：
5.6
通讯作者：
Nicoletti, F
中科院分区：
文献类型：
--
作者：
Papaccio, G;Graziano, A;Nicoletti, F
Interleukin (IL)-1beta-treated rat islets of Langerhans were exposed in vitro either to the imidazoline compound, Efaroxan, or to the selective inducible nitric oxide synthase (iNOS) inhibitor, 1400W, in a medium containing a high concentration of glucose (16.7 mmol/L). Our data have evidenced the following: (i) addition of Efaroxan to islet cultures inhibited IL-1beta activation of ICE (cysteine protease IL-1beta converting enzyme) while addition of 1400W did not. Thus, Efaroxan completely inhibited IL-1beta-induced suppression of insulin secretion and induction of NOS mRNA transcripts, and, in addition, counteracted islet P-cell protein profile alterations, Bax-cytochrome c translocation, caspase activation, and apoptosis; (iii) 1400W inhibited IL-1beta induction of iNOS, but failed to completely counteract the other cytotoxic effects; (iv) the two compounds, moreover, exerted different effects on manganese superoxide dismutase (MnSOD), in fact, while Efaroxan inhibited the early stimulatory effect of IL-1beta on MnSOD, 1400W did not. Thus, Efaroxan completely protected islet beta cells from damage caused by IL-1beta-induced toxicity, while compound 1400W only inhibited NO radical production without altering the cytokine's cytotoxicity. Our observations have evidenced that suppression of ICE activation is required to counteract IL-1beta-mediated islet beta cell toxicity, and that IL-1beta-induced apoptosis is NO-independent and involves the cytochrome c-i-nitochondrial pathway. (C) 2004 Wiley-Liss, Inc.
