With advancing age, many organs exhibit functional deterioration. The age-associated accumulation of senescent cells is believed to represent one factor contributing to this phenomenon. While... Show moreWith advancing age, many organs exhibit functional deterioration. The age-associated accumulation of senescent cells is believed to represent one factor contributing to this phenomenon. While senescent cells are found in several different organ systems, it is not known whether they arise independently in each organ system or whether their prevalence within an individual reflects that individual's intrinsic aging process. To address this question, we studied senescence in two different organ systems in humans, namely skin and T cells in 80 middle-aged and older individuals from the Leiden Longevity Study. Epidermal p16INK4a positivity was associated with neither CD4(+) nor CD8(+) T-cell immunosenescence phenotype composites (i.e., end-stage differentiated/senescent T cells, including CD45RA(+)CCR7(-)CD28(-)CD27(-)CD57(+)KLRG1(+) T cells). Dermal p16INK4a positivity was significantly associated with the CD4(+), but not with the CD8(+) immunosenescence composite. We therefore conclude that there is limited evidence for a link between skin senescence and immunosenescence within individuals. Show less
Cellular senescence is a defense mechanism in response to molecular damage which accumulates with aging. Correspondingly, the number of senescent cells has been reported to be greater in older than... Show moreCellular senescence is a defense mechanism in response to molecular damage which accumulates with aging. Correspondingly, the number of senescent cells has been reported to be greater in older than in younger subjects and furthermore associates with age-related pathologies. Inter-individual differences exist in the rate at which a person ages (biological age). Here, we studied whether younger biological age is related to fewer senescent cells in middle-aged individuals with the propensity for longevity, using p16INK4a as a marker for cellular senescence. We observed that a younger biological age associates with lower levels of p16INK4a positive cells in human skin. Show less