Oxidative stress induces apoptosis via NF-kappaB-iNOS-nitric oxide pathway in pancreatic beta-cells / 中国应用生理学杂志

ABSTRACT

<p><b>AIM</b>To explore the possible mechanism of tert-butyl hydroperoxide (t-BHP)-induced apoptosis in murine MIN6 pancreatic beta-cells.</p><p><b>METHODS</b>MIN6 cells were cultured in vitro. Cell damage was evaluated by epifluorescence microscopy after staining with AO-EB. The percentage of cell apoptosis was determined by flow cytometric assay after Annexin- V-PI staining. Nitric oxide levels were measured by Griess assay. Inducible nitric oxide synthase(iNOS) protein and NF-kappaBp65 fragment were detected by Western blot.</p><p><b>RESULTS</b>Exposure of 25 micromol/L t-BHP to MIN6 cells for 60 min, cell viability was reduced and the percentage of apoptosis was increased significantly. The levels of cytoplasmic iNOS protein and nitrite were elevated. Meanwhile, treatment with t-BHP resulted in nucleus NF-kappaBp65 fragment peaking at 20 min. Both L-NAME and N-Acetyl-l-cysteine (NAC) attenuated the elevated levels of nitrite and percentage of apoptosis due to t-BHP alone.</p><p><b>CONCLUSION</b>NF-kappa-iNOS-nitric oxide signalling pathway can mediated t-BHP induced apoptosis in MIN6 cells .</p>