A range of research groups are presently working on the development of biomarkers based on gene expression changes that occur with aging. Insofar as everyone suffers the same forms of cell and tissue damage that causes aging, it should be expected that cellular reactions to rising levels of that damage have similar patterns, albeit mixed in with environment effects and individual differences. A robust biomarker of aging would be a very useful thing to have to hand, as without it the only way to prove that a potential rejuvenation therapy in fact extends healthy life is to wait and see. That is slow and expensive, even in mouse studies, and this cost is a ball and chain holding back the pace of progress.
Researchers examined expression of genes in blood samples from 15,000 people across the world. They found 1,450 genes that are linked to ageing, and also uncovered a link between these genes and factors such as diet, smoking and exercise. The research team specifically looked for changes in gene expression, a process in which the information contained in genes is 'expressed' by reading the DNA sequence and creating RNA, and subsequently proteins. By looking in blood, the researchers aimed to find easy to measure markers of human ageing. This technique allowed them to develop a new method to predict people's 'biological age' and show that people with a biological age older than their actual age were more likely to have conditions such as high blood pressure or cholesterol. Many of the genes work together in pathways such as generating the energy supply of the cells (mitochondrial function), metabolic processes, and the stability and flexibility of the cells.
"This study has discovered many genes that change in their patterns of expression with age. This study has not only given insights into ageing mechanisms - such as mitochondrial function - but these techniques have potential use in prediction and treatment. Large, observational, and collaborative projects such as these provide a great platform to focus ageing research in the future, with the hope that predictive tests can be developed, and treatment strategies for age-related conditions improved."