Analysis explores DNA methylation clock accuracy throughout tissues

A brand new analysis paper was printed in Getting older (Getting older-US) on January 3, 2025, in Quantity 17, Challenge 1, titled “Characterization of DNA methylation clock algorithms utilized to numerous tissue varieties.”

Researchers Mark Richardson, Courtney Brandt, Niyati Jain, James L. Li, Kathryn Demanelis, Farzana Jasmine, Muhammad G. Kibriya, Lin Tong, and Brandon L. Pierce from the College of Chicago and College of Pittsburgh, studied how organic ageing is measured utilizing DNA. Their research discovered that whereas generally used “DNA methylation clocks” work nicely for blood samples, they might be much less dependable for different tissues just like the lungs, colon, and kidneys.

DNA methylation clocks are extensively utilized in forensic science, epigenetics and longevity analysis to estimate an individual’s organic age based mostly on chemical modifications in DNA. These epigenetic clocks assist scientists predict age-related illnesses and assess how way of life elements, corresponding to smoking, affect ageing. Most had been initially developed utilizing blood samples, and their effectiveness in different tissues stays unclear. This research examined eight totally different DNA methylation clocks throughout 9 human tissue varieties, together with the lungs, prostate, ovaries, skeletal muscle, and kidneys. The researchers analyzed knowledge from 973 tissue samples collected via the Genotype-Tissue Expression (GTEx) challenge.

Their evaluation revealed vital variations in organic age estimates throughout tissues. Whereas blood samples supplied probably the most dependable outcomes, different tissues confirmed noticeable variations. For instance, testis and ovary tissues appeared youthful than anticipated, whereas lung and colon tissues appeared older. 

“These variations throughout tissue varieties had been most obvious for clocks educated utilizing DNAm from blood solely (e.g., Hannum), but in addition current for clocks educated on a number of tissue varieties (e.g., Horvath, a clock designed for pan-tissue age prediction.” 

These findings counsel that ageing might not happen on the similar fee in each organ, and that commonplace DNA methylation clocks might not at all times give correct organic age estimates outdoors of blood samples. The authors counsel that new, organ-specific epigenetic clocks could also be wanted to enhance organic age prediction. Creating tissue-specific ageing clocks may additionally enhance medical diagnostics, age-related illness prevention, and well being monitoring.

The researchers emphasize that bigger research with extra tissue-specific DNA methylation knowledge are wanted to refine these ageing clocks. By bettering these instruments, scientists can higher perceive how ageing impacts totally different organs and develop extra dependable strategies for measuring organic age. These developments may result in higher predictions of age-related illnesses and new methods for wholesome ageing.