New research from the University of Liverpool, published in Nature Scientific Reports, has identified that ageing has distinct and opposite effects on the genes expressed in the tendons of males and females.

Tendons are bundles or bands of strong fibres that attach muscles to bones. Tendons transfer force from the muscle to the bone to produce the movement of joints.

Tendinopathy is a set of tendon disease that results in the tendons not functioning normally. Its development increases in frequency with age.

The University of Liverpool reports that, in the first study of its kind, researchers from its Institute of Ageing and Chronic Disease, analysed in parallel a number of gene datasets from male and females from two age groups (twenty to twenty four years olds and fifty four to seventy years old) to identify sex-specific gene expression changes with age.

Every cell in a human body contains a complete set of chromosomes with every gene needed to make every protein that that organism will ever make. However only a very small fraction of these genes are ever expressed in specific tissues at any one time. Each cell is specialised to carry out certain tasks and will only need to express certain genes. Gene expression is the process by which specific genes are activated to produce a required protein. The researchers analysed these genes and identified distinct molecular pathways which affect ageing in tendon dependant on sex.

The results identify that in old males decreased expression of the binding protein CRABP2 leads to rapid reproduction of cells (cellular proliferation), whereas in old females it leads to the loss of a cell’s power of division and growth (cellular senescence). The results highlight the importance of sex differences which are frequently neglected in gene expression studies.

Lead researcher Dr Mandy Peffers, said “Our research highlights the possible need to treat tendon disease differently in males and females because alternative mechanisms may be involved. Our findings could help in the treatment of more bespoke treatments for this large patient group.”

Mandy Peffers is funded through a Wellcome Trust Clinical Intermediate fellowship. This research was supported by the Medical Research Council (MRC) and Arthritis Research UK as part of the MRC – Arthritis Research UK Centre for Integrated research into Musculoskeletal Ageing (CIMA).