Ageing is a complex process caused by a combination of environmental, genetic and epigenetic factors. A valuable tool for measuring the degree of "healthy ageing" is the expression of genes/biomarkers associated with ageing, that can possibly predict the extent of a person's health.
A key feature of ageing is chronic inflammation, which is a major risk factor for morbidity and mortality in the elderly. Chronic inflammation is associated with many diseases. However, the relationship between age and inflammation is still unclear. Ageing is characterized by an overall decrease in cellular functions and is accompanied by damage to DNA, RNA and protein functions. Our body can detect these lesions and elicit immune responses to remove apoptotic cells. However, as cells age, their reduced energy production can interfere with these energy-purifying cellular cleansing processes, resulting in subsequent inflammatory reactions.
Also characteristic of ageing is the gradual reduction in the expression of Klotho, an important gene involved in many normal cell processes. Klotho gene was named after the fate of Klotho who, according to Greek mythology, weaved the thread of life and controlled the final fate of humans. Surprisingly, Klotho gene deficiency dramatically reduced the lifespan of mice, while its overexpression in mice caused a ~ 30% increase in their lifespan!
In addition, the natural ageing process and various pathologies are associated with alterations in the structural and mechanical integrity of connective tissue. Collagens represent the most common proteins in the extracellular space and provide the overall stiffness and strength of tissues. Structural changes in collagen and their susceptibility to degradation are associated with skin wrinkles, reduced bone and cartilage quality, and cardiovascular and respiratory disorders. Collagen production decreases during ageing.
People of the same age may not age at the same rate. In our lab, we have developed a new molecular blood test, which is able to quantify with great accuracy the relative expression of genes associated with ageing. Specifically, COX2 (cyclooxygenase-2), TNFα (tumor necrosis factor alpha), TGF-β1 (Transforming growth factor beta 1) (inflammation biomarkers), GABPB1 (cell energy biomarker), COL1A1 (major collagen), Klotho (youth biomarker), TERT (immortality gene) expression is determined in relation to the expression of reference genes. Thus, the exact status of the gene activity related to ageing and consequently the actual biological age of each individual is determined individually.