P2RX7 Antagonism Reduces Macrophage Senescence in the Aging Kidney
Cells become senescent constantly throughout life in response to various forms of damage and stress, ceasing replication and generating a potent mix of inflammatory signals. In youth, these cells are promptly cleared by the immune system, but with advancing age they begin to linger and accumulate. The inflammatory signaling becomes disruptive to tissue structure and function when sustained over the long term, and this is an important contribution to degenerative aging. Here, researchers show that macrophage cells in the kidney express increasing amounts of the P2RX7 receptor on the cell surface as they progress towards becoming senescent, and blocking this receptor with a suitable antagonist small molecule reduces macrophage senescence and improves kidney function.
Macrophage senescence is a pathological feature in aging or diseased kidneys. However, the role of senescent macrophages in kidney injury and aging has not been fully elucidated yet. We integrated the analysis of single-cell RNA sequencing datasets and the adoptively transfusion of pretreated bone marrow-derived macrophages to investigate the role of renal macrophage senescence in kidney injury. Here, we portrayed the senescence trajectory along multiple time points in infiltrating macrophages, and observed the persistent increase of macrophage-expressed purinergic receptor P2RX7 along the senescence trajectory in injured kidneys of septic mice.
Importantly, our discovered small-molecule P2RX7 antagonist strikingly improved kidney function and pathological damage, as well as mitigated macrophage senescence in septic and aging mice. Mechanistically, P2RX7 antagonist could promote the wound healing, migration, and proliferation capacity of senescent reparative macrophages, thus exerting anti-inflammatory effects and repairing kidney tissues. Together, our findings illustrate the crucial participation of senescent macrophages in septic kidney injury, and offer novel therapeutic strategy via intervening P2RX7 against immunosenescence-associated kidney injury and aging.