Molecular mechanisms and recent advances in cellular senescence

Senescence is an adaptive cellular mechanism initiated in response to diversified intrinsic and extrinsic stress stimuli, that lead to altered cellular and pathophysiological state. In this article we will review the comprehensive role of variable factors like oxidative stress, telomere attrition and oncogene activation in the initiation of senescence. Cells have a robust Redox system in place to counteract the effects of ROS/RNS mediated cell organelles and macromolecular damage to prevent senescence. The morphological, physiological and metabolic changes associated with progression of senescence and their molecular regulation at transcriptional and posttranscriptional levels has also been highlighted. The signaling pathways like p53/p21 and p16/pRB governing the senescence associated proliferative arrest and other complex cellular mechanisms that modulate the development and regulation of senescence associated secretory phenotype has been discussed in detail.