Considering Cellular Senescence in Macrophages

Cells become senescent in response to damage, a toxic environment, the signaling of nearby senescent cells, or, most commonly, because they reach the Hayflick limit on replication. Senescent cells cease replication and begin to secrete pro-inflammatory signals, attracting the attention of the immune system. With advancing age he aged immune system becomes less able to clear senescent cells in a timely manner, leading to a growing, permanent presence of senescent cells in tissues. Some of these senescent cells are themselves immune cells. Given the importance of the immune system to tissue maintenance and regeneration, particularly tissue residence innate immune cells such as macrophages, it should be no surprise to find that senescence in these cells is viewed as contributing to degenerative aging. Macrophage senescence, manifested by the special form of durable cell cycle arrest and chronic low-grade inflammation like senescence-associated secretory phenotype, has long been considered harmful. As the first-responder to the pathogens and damage in the immune response, macrophages play a vital role in the function of phagocytosis and polarization towards different situations to mediate the inflammation inside individuals. Senescent macrophages are usually featured with an unbalanced polarization state, compromised phagocytosis, impaired migration, and damaged autophagy. Due to the abnormal accumulation and the aberrant functions of senescent macrophages, aged people t...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs