Fig. 8

Panx1 overexpression increases resting levels of extracellular ATP and gene expression in muscle L6 cells. a Extracellular ATP resting levels are increased in L6 muscle cells overexpressing Panx1 (L6-Panx1), both in myoblast and in myotube differentiation stages (n = 3). b ATP release evoked by electrical stimulation (20 Hz, 270 pulses, 0.3 ms each) is increased in Panx1 overexpressing cells. ATP release induced by ES is graphed as fold increase compared to non-stimulated cells (n = 3). c mRNA resting levels of E-T coupling related genes (cfos, citrate synthase, PGC1α, and interleukin 6) in either mock or Panx1-overexpressing L6 myotubes,were analyzed by qPCR (n = 3-4). d Interleukin 6 mRNA levels evoked by ES in both mock and Panx1-overexpressing L6 myotubes were analyzed by qPCR (n = 3–4). GAPDH was used as a housekeeper gene for normalization. The dashed line (b–d) marks the value of “1” to indicate the level of expression of IL6 in cells without ES, against which the results are normalized. Values are expressed as mean ± SEM. *p < 0.05; **p < 0.01; ***p < 0.001. All the assays were performed after overnight 5 mM sodium butyrate incubation, to improve Panx1 overexpression as detailed in Fig. 5