Cellular Senescence in the Aging Brain, a Contributing Cause of Cognitive Decline

Senescent cells are created throughout the body at all stages of life, largely when somatic cells reach the Hayflick limit on replication. Senescent cells cease replication and begin to energetically produce pro-growth, pro-inflammatory factors, attracting the attention of the immune system and otherwise changing the behavior of surrounding cells. Cell stress and mutational damage can induce senescence, and in this case senescence is a mechanism that acts to limit the risk of cancer. Tissue injury also produces senescent cells, and here they help to coordinate the activities of the many different cell types that become involved in the complex process of regeneration. In youth, senescent cells are promptly destroyed, either through programmed cell death mechanisms, or by attracting the attention of immune cells. In later life, the immune system becomes less efficient in its task of clearing senescent cells. This leads to a growing burden of lingering senescent cells. While the signals generated by senescent cells are useful in the short-term, when sustained over the long-term they become disruptive to tissue structure and function, contributing to the chronic inflammation of aging. Researchers are coming to see the inflammation of aging as an important mechanism in the aging of the brain and the onset of neurodegenerative conditions, and so attention is turning, slowly, to whether clearance of senescent cells is a viable treatment for Alzheimer's disease, Parkinson's di...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs