N-Alkyl-Substituted Isatins Enhance P2X7 Receptor-Induced Interleukin-1β Release from Murine Macrophages

Figure 4

NAI or NAI-imine increase P2X7-mediated IL-1β release but not ethidium⁺ uptake. LPS-primed J774 cells in physiological medium were preincubated in the presence of DMSO, or 1 μM NAI or 1 μM NAI-imine for 30 min, and then in the absence or presence of 3 mM ATP for ((a) and (b)) 20 min or (c) 5 min in the presence of 25 μM ethidium bromide. (a) The IL-1β concentration in cell-free supernatants was measured using an ELISA. (b) The LDH activity in cell-free supernatants and cell lysates was measured using a cytotoxicity kit, and results are expressed as a percentage of maximal LDH release from lysed cells. (c) Ethidium⁺ uptake was measured by flow cytometry and is expressed as mean fluorescence intensity (MFI). ((a) to (c)) Results are mean ± SD (); or compared with corresponding basal; ^† or ^††† compared with DMSO and ATP.

(a)

(b)

(c)