Figure 1.

P2RX7 activation induces LP formation and cell death in dystrophic myoblasts. (A) Examples of EtBr fluorescence in wild-type (Wt) and dystrophic Dmd^mdx myoblasts following 30 min exposure to 3 mM eATP in LP buffer (left panels). Right panels show EtBr uptake following the same treatment in myoblasts isolated from Dmd^mdx p2rx7^−/− double-mutant mice and Dmd^mdx myoblasts after inhibition of P2RX7 by 30 min preincubation with 100 μM A438079. Inset in Dmd^mdx panel shows classic ‘macrophage-like’ membrane blebbing following exposure of Dmd^mdx myoblasts to eATP. (B) Summary data showing EtBr uptake dependence on P2RX7 expression in Wt, Dmd^mdx and Dmd^mdx p2rx7^−/− myoblasts exposed to 3 mM eATP for 30 min (C). eATP dose response of EtBr uptake in Wt and Dmd^mdx myoblasts exposed to indicated concentrations of ATP for 30 min, with or without preincubation with 100 μM A438079. Digitonin represents permeabilized positive control. (D) PrestoBlue fluorescence (cell viability) in Wt, Dmd^mdx, and Dmd^mdx p2rx7^−/− myoblasts following 30 min exposure to 3 mM eATP. (E) LDH release from Wt, Dmd^mdx, and Dmd^mdx p2rx7^−/− myoblasts following 30 min exposure to 3 mM eATP with or without the P2RX7-specific inhibitor, A804598 (100 nM). Mean +/− SE, n = 5, P < 0 .05* and 0.0001***.