chapter  15
22 Pages

Mechanical Signaling in the Urinary Bladder

All tissues in the human body are mechanically responsive; the sensing of physical pressure and stretch from the external environment modulates developmental or adaptive responses in cells from the earliest stages of embryogenesis to later stages of differentiated adult organs and tissues. Hollow organs such as the lungs, heart, vasculature, and the urinary bladder are particularly sensitive to mechanical stimuli since their primary function is to mediate an appropriate response to physical forces, whether regulating airway caliber during each breath or initiating voiding in response

15.1 Introduction .......................................................................................................................... 327 15.1.1 Overview ................................................................................................................... 328

15.2 How to Study Mechanical Signaling in Bladder Smooth Muscle ........................................ 328 15.2.1 In Vitro Assays of Mechanical Signaling ................................................................. 328

15.2.1.1 Modi™ed Patch-Clamp Single Cell Stretch ................................................ 328 15.2.1.2 Traction Force Microscopy ........................................................................ 329 15.2.1.3 Cell Mapping Rheometry .......................................................................... 329 15.2.1.4 Optical Magnetic Twisting Cytometry ...................................................... 331 15.2.1.5 Membrane-Based Strain-Transducing Devices ......................................... 332

15.2.2 Ex Vivo Assays of Mechanical Signaling ................................................................. 333 15.2.2.1 Organ Bath Studies with Muscle Strips ..................................................... 333 15.2.2.2 Ex Vivo Bladder Distension Models .......................................................... 334

15.2.3 In Vivo Analysis of Mechanotransduction ................................................................ 334 15.2.3.1 Complete Bladder Outlet Obstruction........................................................ 334 15.2.3.2 Partial Bladder Outlet Obstruction ............................................................ 334 15.2.3.3 Neurogenic Obstruction Models ................................................................ 335 15.2.3.4 Bladder Hydrodistension ............................................................................ 335

15.3 Mechanoresponsive Signaling Networks in Bladder Smooth Muscle .................................. 335 15.4 The Role of the Extracellular Matrix in Mechanotransduction ........................................... 338 15.5 Smooth Muscle-Epithelial Interactions in Bladder Mechanotransduction ........................... 339 15.6 Mechanotransduction in Disease and Potential Strategies for Therapeutic Intervention .....340