Nicholas A. Delamere, Professor and Head, Dept. of Physiology; Professor, Dept. of Ophthalmology & Vision Science, University of Arizona will be delivering a seminar on “A Form of Control: TRPV4 Channels in the Eye” on Wednesday, February 21st at 12:00 Noon in the Moran Eye Center auditorium.
Abstract: Lens transparency requires precise maintenance of ion and water content (homeostasis), something that is difficult to achieve because of the unique properties of lens cells. The seminar will discuss how a particular type of ion channel, TRPV4, acts as a sensor in a remote control mechanism that makes homeostasis possible. The case will be made that lens TRPV4 is activated by mechanical forces. It will be argued that TRPV4 activation works like a switch that opens connexin hemichannels, causing the lens to release signaling molecules that adjust Na,K-ATPase activity in its epithelium monolayer. The significance to human well-being is that cataract is frequently associated with failed homeostasis. In a broader context, the seminar will review TRPV4 expression in other parts of the eye. The ciliary body also uses TRPV4 to sense and respond to mechanical stimuli, perhaps to adjust the driving force for aqueous humor secretion.