Cellular theory of aging states that human aging is the result of cellular aging, in which an increasing proportion of cells reach senescence. Senescence, from the Latin word senex, means “growing old,” is an irreversible growth arrest which occurs in response to damaging stimuli, such as DNA damage, telomere shortening, telomere dysfunction and oncogenic stress leading to suppression of potentially dysfunctional, transformed, or aged cells. Cellular senescence is characterized by irreversible cell cycle arrest, flattened and enlarged morphology, resistance to apoptosis, alteration in gene expression and chromatin structure, expression of senescence associated- β-galactosidase (SA-β-gal) and acquisition of senescence associated secretory phenotype (SASP). In this review paper, different types of cellular senescence including replicative senescence (RS) which occurs due to telomere shortening and stress induced premature senescence (SIPS) which occurs in response to different types of stress in cells, are discussed. Biomarkers of cellular senescence and senescent assays including BrdU incorporation assay, senescence associated- β-galactosidase (SA-β-gal) and senescence-associated heterochromatin foci assays to detect senescent cells are also addressed.

细胞衰老理论指出，人类衰老是细胞衰老的结果，其中越来越多的细胞达到衰老。衰老来自拉丁语senex，意为“变老”，是一种不可逆的生长停滞，其发生是由于DNA损伤，端粒缩短，端粒功能障碍和致癌性应激等破坏性刺激而导致的潜在功能障碍，转化或抑制。老化的细胞。细胞衰老的特征是不可逆的细胞周期停滞，形态扁平化和扩大，对凋亡的抵抗力，基因表达和染色质结构的改变，衰老相关的β-半乳糖苷酶（SA-β-gal）的表达以及衰老相关的分泌表型的获得（ SASP）。在这篇评论文章中，讨论了不同类型的细胞衰老，包括由于端粒缩短引起的复制性衰老（RS）和响应细胞中不同类型的应激而发生的应激诱导的早衰（SIPS）。还讨论了细胞衰老和衰老测定的生物标记物，包括BrdU掺入测定，衰老相关的β-半乳糖苷酶（SA-β-gal）和衰老相关的异染色质病灶检测，以检测衰老细胞。