Tendon cells can rebound from stiffness when returned to softer tissue-like surroundings

Researchers at Queen Mary University of London have gained fresh insight into tendinopathy, a prevalent condition that leads to chronic pain and movement limitations in humans and animals. Their study, published in Advanced Science, reveals that tendons are composed of various cell populations with distinct physical environments.

The team specifically investigated cells within the interfascicular matrix (IFM), the softer tissue that links the collagen bundles in a tendon. These IFM cells proved to be particularly responsive to alterations in their mechanical surroundings, unlike other tendon cell populations.

When exposed to stiff substrates, IFM cells underwent significant structural shifts, altered the expression of genes related to tendon function and extracellular matrix production, and experienced a decline in their proliferation ability. However, returning these cells to softer, IFM-like substrates led to a recovery of their morphology and proliferation, along with partial restoration of certain gene-expression alterations.

This observation underscores the critical role of the physical environment in maintaining tendon cell behavior and characteristics.

Dr. Simon Grossemy, the lead researcher, emphasized the importance of understanding how different cell populations respond to changes in the tendon's mechanical environment, as tendons can undergo structural and stiffness modifications during disease. Professor Hazel Screen, the principal investigator, noted that the recovery observed in IFM cells when transferred to a softer environment highlights the impact of physical factors on cell behavior and tissue health.

This research offers valuable perspectives on tendon injury prevention, management, and repair in both humans and animals, particularly in light of the difficulty in treating tendinopathy due to limited understanding of the underlying biological processes.