Inhibition of the p38 and JNK signaling pathways by chemical compounds reduces osmostress-induced apoptosis.

<p>A and B. p38 inhibitors do not modify osmostress-induced apoptosis. Oocytes were pre-incubated in MBS with SB203580 (100 μM) or BIRB796 (100 μM) for 1 h and then treated with 300 mM sorbitol in the presence of inhibitors. Caspase-3 activity was determined at different times giving value 1 to non treated oocytes. Data are represented as mean ± SEM, (n = 4). pp38, pJNK, pAMPK, AMPK and cytochrome c (CC) release were determined by Western blot at 3 h after treatment. C and D. The JNK inhibitor SP600125 (100 μM) does not reduce osmostress-induced apoptosis. Oocytes were pre-incubated with the inhibitor, treated as described previously, and caspase-3 activity was determined at different times. Data are represented as mean ± SEM (n = 6) and analyzed with Paired t-test comparing control versus inhibitor treatment. * p<0.05. The Western blot shows results at 1 and 3 h after treatment. E and F. BIRB796 + SP600125 treatment reduces osmostress-induced apoptosis. Oocytes were incubated with 100 μM BIRB796 plus 100 μM SP600125, treated as described before, and caspase-3 activity analyzed. Data are represented as mean ± SEM, (n = 3). * p<0.05 (Paired t-test). pp38, pJNK, JNK, cleaved caspase-3, and cytochrome c (CC) release were determined by Western blot at 3 and 4 h after treatment. The Western blots in all figures are representative of at least three independent experiments.