From the Guidelines
Biomarkers of senescent cells include p16, p21, senescence-associated beta-galactosidase, and SASP factors, as well as markers of DNA damage such as γ-H2A.X and 53BP1, which are the most robust markers employed in senescence studies 1. These biomarkers provide measurable indicators of cellular aging processes and are valuable for assessing biological age, evaluating anti-aging interventions, and understanding the mechanisms underlying age-related diseases.
- Telomere shortening and DNA methylation patterns are also important biomarkers of aging cells, as they change predictably with age and can be used to estimate biological age.
- Senescent cells accumulate lipofuscin and express beta-galactosidase at higher levels, making these useful laboratory markers.
- The SASP involves the release of inflammatory cytokines, growth factors, and proteases that can damage surrounding tissues and promote aging-related diseases.
- Recent guidelines suggest that the assessment of senescence markers in human samples should begin with the measurement of total amount of protein, such as p16Ink4a, p21, or LMNB1, or larger cytoplasmic inclusions, such as lipofuscin, which are stable for a prolonged period of time 1.
- The development of senescence biomarkers compatible with minimally invasive methodologies, such as blood or urine samples, would greatly enhance access to healthy human populations and allow for more accurate assessment of biological age and senescence burden 1.
- A sequential approach to study senescence in vivo, including the detection of cell cycle arrest proteins, verification of the phenotype, reduction of senescence, and consequences of reduction, is recommended to accurately assess the relevance of cellular senescence to a specific phenotype 1.
From the Research
Biomarkers of Senescent Cells
- The senescence-associated secretory phenotype (SASP) has been identified as a driver of age-related conditions, and its complexity has been greatly underestimated 2.
- Several candidate biomarkers of cellular senescence have been identified, including:
- Telomere length (TL) has also been recognized as a biomarker of aging, with shorter telomeres indicating replicative senescence and a higher probability of cell senescence 4, 5, 6.
- However, the use of TL as a biomarker is limited, and other indicators such as immune parameters and indices of epigenetic age may be stronger predictors of health status and risk of chronic disease 4, 6.