Biomechanical regulation of bladder injury and repair.

The urinary bladder is a hollow, muscular organ that functions to store and void urine cyclically. The bladder has a dynamic mechanical environment owing to its cyclical expansion and contraction, along with the accumulation and outflow of urine. These complex mechanical stimuli, via diverse mechanosensors and downstream mechanotransduction, modulate bladder sensation, detrusor contraction in the bladder and remodelling of the bladder wall, thereby maintaining the functional homeostasis of the bladder. Mechanical homeostasis of the bladder can be disrupted by disease or injury, such as elevated stretch force and hydrostatic pressure in bladder outlet obstruction and increased matrix stiffness after bladder fibrosis. Abnormal mechanical environments are indicative of bladder diseases and also contribute to the progression of bladder injury and disease. Hence, understanding the effects of regulatory mechanisms of biomechanical cues on bladder function under both physiological and pathological conditions, clarifying the connections and distinctions between these states, and identifying the differential mechanical sensations and transduction pathways that drive bladder diseases and injuries are essential for developing novel therapeutic strategies targeting mechanotransduction pathways to promote the repair of injured or diseased bladders.