Figure 2.

P2X7R expression and function in IVD cells. During the dedifferentiation process from Passage 0 (P0) to Passage 2 (P2) P2X7R expression was analyzed. (a) The cells were subjected to RT‐PCR, the expression was normalized against GAPDH as endogenous control, and calculated as fold change versus P0 (mean ± SD). Data were analyzed by Student's t‐test, *p < 0.05, significantly different from P0 (P0 group, n = 7; P2 group, n = 7). The cells were subjected to RT‐qPCR. (b) For investigating the presence of P2X7RA and P2X7RB isoforms. For mRNA analysis, data were normalized against GAPDH as endogenous control, calculated as change versus P2X7RA (P0), and expressed as mean ± SD. Data were analyzed by Student's t‐test, *p < 0.05 significantly different from P0 (P0 group, n = 7; P2 group, n = 7). (c) IVD cells were subjected to P2X7R function analysis. Representative traces showing the increment of intracellular calcium (on the left) and ethidium bromide uptake (on the right), following 500 μM BzATP stimulation (n = 5). GAPDH, glyceraldehyde 3‐phosphate dehydrogenase; IVD, intervertebral disc; mRNA, messenger RNA; P2X7R, P2X7 purinergic receptor; RT‐qPCR, reverse transcription quantitative real‐time polymerase chain reaction analysis