Inherent P2X7 Receptors Regulate Macrophage Functions during Inflammatory Diseases
Wenjing Ren1,2, Patrizia Rubini1,2, Yong Tang1,2
1International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of TCM, Chengdu 610075, China.
International Journal of Molecular Sciences
|January 11, 2022
Summary
Macrophages utilize P2X7 receptors (Rs) to regulate immune responses. Targeting these P2X7Rs on macrophages may offer therapeutic strategies for inflammatory diseases by preserving immune homeostasis.
Area of Science:
- Immunology
- Cell Biology
- Molecular Medicine
Background:
- Macrophages are critical immune cells with diverse roles, existing as M1 (pro-inflammatory) or M2 (anti-inflammatory) phenotypes.
- These cells originate from monocytes or reside in tissues like the liver, spleen, and lungs.
- Macrophages express P2X7 receptors (Rs), which are involved in cellular responses to extracellular ATP.
Purpose of the Study:
- To investigate the role of macrophage P2X7 receptors in immune regulation and inflammatory processes.
- To explore the molecular mechanisms underlying P2X7R activation and its downstream effects.
- To assess the therapeutic potential of targeting macrophage P2X7Rs for inflammatory diseases.
Main Methods:
- Analysis of P2X7 receptor (R) function in macrophages under varying ATP concentrations.
- Investigating the interaction of P2X7R with other membrane channels (e.g., P2X4R, TRPA1, pannexin-1, ANO6).
- Examining the co-activation of P2X7R with toll-like receptor 4 (TLR4) and its role in inflammasome (NLRP3) activation and IL-1β release.
Main Results:
- High extracellular ATP concentrations activate P2X7Rs, leading to cation fluxes and pore formation permeable to large molecules.
- P2X7R activation requires interaction with other membrane channels for full functional response.
- Co-activation of macrophage P2X7Rs and TLR4 is essential for NLRP3 inflammasome assembly and subsequent caspase-1 activation, driving IL-1β release.
- P2X7R signaling contributes to the upregulation of inflammatory mediators and pathways implicated in diseases like rheumatoid arthritis and sepsis.
Conclusions:
- Macrophage P2X7 receptors play a pivotal role in initiating inflammatory responses.
- The intricate interplay between P2X7R, TLR4, and inflammasome components is crucial for immune cell activation.
- Targeting macrophage P2X7Rs presents a promising therapeutic avenue for managing inflammatory conditions and maintaining immune homeostasis.
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