December 20, 2014

Epithelial tube contraction

A new feedback mechanism for regulating contractility

Many of the fundamental processes of life rely on biological structures known as epithelial tubes. These tubes serve to transport various gases, liquids and cells around the body. With each breath, for example, epithelial tubes transport oxygen to the lungs. Our blood vessels, kidneys and pancreas, mammary, salivary and tear glands, are all essentially composed of epithelial tubes. However, these tubes are more than just a biological plumbing system. Instead, they are dynamic structures which must counter outward pressures to prevent their swelling or rupture. An intrinsic ability of epithelial tubes to constrict helps maintain their integrity. This constriction results from actomyosin contractility, a co-ordinated movement of filaments made of a protein known as actin, and a motor protein known as myosin. Problems in epithelial tube contractility are responsible for asthma, raised blood pressure and gastrointestinal disorders. Each one of these diseases affects millions of people worldwide, dramatically affecting their quality of life.