Further Information: | Cells are the basic unit of biological structure and function, as well as the basic unit of biological aging. Cellular senescence is morphologically manifested as degeneration of cell structure, such as nuclear membrane depression, which eventually leads to nuclear membrane collapse, chromatin structure changes, and the number of hyperdiploid and abnormal polyploid cells increases; cell membrane fragility increases. Sexual permeability decreases, and the types and numbers of membrane receptors and the sensitivity to ligands change; lipofuscin accumulates in cells, and many organelles and intracellular structures undergo degeneration. Cell senescence is physiologically manifested as functional decline and low metabolism, such as cell cycle arrest, loss of cell replication ability, weakened responsiveness to mitogenic stimulation, and changes in responsiveness to pro-apoptotic factors; intracellular enzyme active centers are oxidized , Enzyme activity decreased, protein synthesis decreased, etc. The senescent cells can no longer replicate, but they still maintain metabolically active and stain positive for senescence-associated ?-galactosidase activity, which is considered to be a biomarker of cellular senescence. |