The epigenetic clock theory of aging

My 400th blog post curates a 2018 US/UK paper by two of the coauthors of Using an epigenetic clock to distinguish cellular aging from senescence. The authors reviewed the current state of epigenetic clock research, and proposed a new theory of aging: “The proposed epigenetic clock theory of ageing views biological ageing as an unintended … Continue reading The epigenetic clock theory of aging

Using an epigenetic clock to assess liver disease

This 2018 UC San Diego human study investigated the capability of the epigenetic clock methodology to detect biological aging with nonalcoholic steatohepatitis (NASH) patients: “The ability to measure a surrogate marker of liver aging from a peripheral blood sample has broad implications for assessing clinically “silent” chronic diseases, such as NASH, and, potentially, their response … Continue reading Using an epigenetic clock to assess liver disease

Using an epigenetic clock with older adults

This 2016 German human study found: “Epigenetic age acceleration is correlated with clinically relevant aging-related phenotypes through pathways unrelated to cellular senescence as assessed by telomere length. The current work employed the frailty index, a multi-dimensional approach that combines [34] parameters of multiple physiological systems and functional capacities. The present findings were based on [1,820] … Continue reading Using an epigenetic clock with older adults

Using an epigenetic clock with children

This 2015 UK human study by many of the coauthors of What’s the origin of the problem of being fat? applied the Horvath epigenetic clock method to the same UK mother-child pairs and a Danish cohort: “There has been no investigation on prenatal and antenatal factors that affect AA [age acceleration] in children. It is … Continue reading Using an epigenetic clock with children

Using an epigenetic clock to distinguish cellular aging from senescence

The 2016 UK/UCLA human study found: “Induction of replicative senescence (RS) and oncogene-induced senescence (OIS) are accompanied by ageing of the cell. However, senescence induced by DNA damage is not, even though RS and OIS activate the cellular DNA damage response pathway, highlighting the independence of senescence from cellular ageing. We used primary endothelial cells … Continue reading Using an epigenetic clock to distinguish cellular aging from senescence

Cell senescence and DNA methylation

This 2018 Baltimore cell study found: “Based on similarities in overall methylation patterns in replicative senescence and cancers, it is hypothesized that tumor-promoting DNA methylation in cancers derives from cells escaping senescence. We show that the tumor-associated methylation changes evolve independently of senescence and are pro-survival events with functional implications contrasting that in senescence. In … Continue reading Cell senescence and DNA methylation

Obtaining convictions with epigenetic statistics?

This 2018 Austrian review subject was forensic applications of epigenetic clock methodologies: “The methylation-sensitive analysis of carefully selected DNA markers (CpG sites) has brought the most promising results by providing prediction accuracies of ±3–4 years, which can be comparable to, or even surpass those from, eyewitness reports. This mini-review puts recent developments in age estimation … Continue reading Obtaining convictions with epigenetic statistics?

How one person’s paradigms regarding stress and epigenetics impedes relevant research

This 2017 review laid out the tired, old, restrictive guidelines by which current US research on the epigenetic effects of stress is funded. The reviewer rehashed paradigms circumscribed by his authoritative position in guiding funding, and called for more government funding to support and extend his reach. The reviewer won’t change his beliefs regarding individual … Continue reading How one person’s paradigms regarding stress and epigenetics impedes relevant research

The cerebellum ages more slowly than other body and brain areas

This 2015 UCLA human study used the epigenetic clock methodology to find: “All brain regions have similar DNAm ages in subjects younger than 80, but brain region becomes an increasingly significant determinant of age acceleration in older subjects. The cerebellum has a lower epigenetic age than other brain regions in older subjects. To study age … Continue reading The cerebellum ages more slowly than other body and brain areas

A followup study of DNA methylation and age

This 2016 Finnish human study was a followup to A study of DNA methylation and age: “At the 2.55-year follow-up, we identified 19 mortality-associated CpG sites that mapped to genes functionally clustering around the nuclear factor kappa B (NF-κB) complex. None of the mortality-associated CpG sites overlapped with the established aging-associated DNAm sites. Our results … Continue reading A followup study of DNA methylation and age