Interplay of damage and repair in the control of epithelial tissue integrity in response to cyclic loading

Epithelial tissues are continuously exposed to cyclic stretch in vivo. Physiological stretching has been found to regulate soft tissue function at the molecular, cellular, and tissue scales, allowing tissues to preserve their homeostasis and adapt to challenges. In contrast, dysregulated or pathological stretching can induce damage and tissue fragilisation. Many mechanisms have been described for the repair of epithelial tissues across a range of timescales. In this review, we present the timescales of (i) physiological cyclic loading regimes, (ii) strain-regulated remodeling and damage accumulation, and (iii) repair mechanisms in epithelial tissues. We discuss how the response to cyclic loading in biological tissues differs from synthetic materials, in that damage can be partially or fully reversed by repair mechanisms acting on timescales shorter than cyclic loading. We highlight that timescales are critical to understanding the interplay between damage and repair in tissues that experience cyclic loading, opening up new avenues for exploring soft tissue homeostasis.