Arguing for a Central Role of Cellular Senescence in the Age-Related Susceptibility to Inflammatory Conditions

Inflammation is a necessary part of the immune response to injury and infection, required in order to defend and rebuild. Normally, inflammation is a cycle of signaling that changes cell behaviors, response followed by resolution. When resolution fails, serious consequences can result. Conditions such as sepsis and severe COVID-19 cases are examples of a runaway inflammatory response leading to a high mortality. Both of these examples are age-related, in the sense that old people are far more susceptible to undergoing such a breakdown of the normal inflammatory feedback loops. The age-related dysfunction of the immune system predisposes it to overactivation and inflammation, just as it also makes the immune response less effective. Senescent cells accumulate with age. These cells are constantly created and cleared in the body, and when present for only a short time play an important role in cancer suppression and wound healing. With age, however, the pace of creation accelerates and pace of clearance by the immune system slows. A constant presence of senescent cells allows their inflammatory, pro-growth senescence-associated secretory phenotype (SASP) to grow to pathological levels, encouraging a rising level of chronic inflammation throughout the body. It is hypothesized that this is an important cause of age-related susceptibility to runaway inflammation in response to circumstances that the regulatory mechanisms of young individual would successfully cope with. ...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs