Figure 3

Pharmacological inhibition of CaMKII and JNK. Inhibition of either CaMKII and JNK is enough to restore activity dependent activation of NFATc1 in the intercostal fibers. (A) Number of nuclei vs N/C ratio after 90 minutes of stimulation (∆N/C(90 min)) relationship in intercostal fibers treated with KN62 (cyan), SP600125 (orange) and corresponding control (red). (B) Average ∆N/C(90 min) in intercostal fibers treated with KN62 (cyan), SP600125 (orange) and corresponding control (red). Note that this effect may be incomplete, resulting in activity-responsive subpopulations (A), but nevertheless represents a significant reversal of the behavior observed in control intercostal fibers (B). Similar treatment of FDB fibers results in significant increase in translocation during stimulation. (C) Average ∆N/C(90 min) in soleus and FDB fibers treated with KN62, SP600125 and corresponding control. Minor increases were also observed in soleus fibers but did not reach significance threshold. (D) Summary of peak indo-1 ratio measurements for intercostal and FDB fibers treated with KN62, SP600125 and corresponding controls. Treatment with kinase inhibitors does not reduce magnitude of indo-1 calcium transients. Averaged traces of indo-1 ratios are also shown (E). Sample size (A, B and C) control n = 40, 37, 38 nuclei from 15, 14, 25 fibers isolated from 4, 4, 3 animals for ItC, Sol and FDB respectively; KN62 n = 56, 7, 4 nuclei from 18, 4, 2 fibers isolated from 5, 2, 1 animals for ItC, Sol and FDB respectively; SP600125 n = 32, 3, 9 nuclei from 11, 2, 4 fibers isolated from 4, 1, 1 animals for ItC, Sol and FDB respectively. Sample size (D and E) KN62 n = 3, 5 fibers for ItC and FDB respectively; SP600125 n = 3, 6 fibers for ItC and FDB respectively. Error bars show SEM.