Table 1.

Representative senescence phenotypic traits and related biomarkers.

Senescent Phenotypes	Senescent Markers	Reference
Morphological changes	Flattened, expanded, and vacuolized cell shape Numerous or enlarged nuclei	[84,85]
Cell cycle arrest	Elevated p53-p21Cip1 and p16Ink4a-Rb activities	[86,87,88,89]
Lysosomal expansion	Increased lysosomal mass and activities (SA-β-gal and lipofuscin)	[83,90,91]
Chromatin reorganization	Elevated senescence-associated heterochromatin foci (SAHF) and senescence-associated distension of satellites (SADS)	[83,92]
Senescence-associated secretory phenotype (SASP)	Increased production and secretion of the SASP components (interleukins, chemokines, and growth factors)	[83,92,93]