Macrophage activation and polarization modify P2X7 receptor secretome influencing the inflammatory process

Area of Science:

• Immunology
• Cell Biology
• Molecular Medicine

Background:

• P2X7 receptor (P2X7R) activation on M1 macrophages triggers NLRP3 inflammasome assembly and pro-inflammatory cytokine release.
• P2X7R signaling to the NLRP3 inflammasome is impaired in M2 macrophages, despite normal receptor activation.

Purpose of the Study:

• To characterize the P2X7R secretome in M1 and M2 polarized macrophages.
• To identify proteins released upon P2X7R stimulation beyond the known caspase-1 secretome.
• To explore a potential role for P2X7R in inflammation resolution.

Main Methods:

• Analysis of P2X7R secretome in wild-type and P2X7R-deficient macrophages.
• Macrophage polarization to M1 and M2 states.
• Stimulation of P2X7R and subsequent secretome analysis.

Main Results:

• P2X7R stimulation releases proteins beyond the caspase-1 secretome.
• The P2X7R secretome is characterized by a fine-tuning of protein release.
• Potent anti-inflammatory proteins, including Annexin A1, are released upon P2X7R stimulation, irrespective of macrophage polarization state.

Conclusions:

• P2X7R activation has a novel function in regulating protein release.
• P2X7R plays a role in the resolution of inflammation by releasing anti-inflammatory proteins.
• These findings are crucial for developing therapeutics targeting P2X7R.