Extracellular Matrix Changes in Response to Obstruction
(PI, Edward J. Macarak, Ph.D.).
Very little is known about the cell-to-matrix cross-talk in smooth muscle. Obstruction causes changes in the ability of muscle cells to transfer force generated by actin-myosin interactions across the cell membrane to other cells and the extracellular matrix. The structures responsible for this force transfer across the Sarcolemma constitute the dystrophin-glycoprotein complex (DGC). Understanding the structures that comprise the DGC and their function will provide diagnostic information about detrusor damage and permit targeted therapeutic intervention to halt or reverse such changes. The goal of this proposal is to characterize the structure and chemistry of the DGC in the detrusor smooth muscle and how it changes following obstruction and reversal, and how this might affect the transfer of force from contractile filaments in the smooth muscle cells to the matrix and the adjacent cell required for muscle shortening during bladder emptying.
Specific aims of this project are:
- To determine the composition of the DGC complex in BSM during obstruction and recovery from obstruction.
- To determine, in bladder smooth muscle cells, the pathway by which the sarcoglycans transit from the ER to the Sarcolemma and to determine the mechanism by which obstruction alters this pathway and to visualize, at the ultrastructural level using Cryo-electron microscopy, the DGC from controls and from obstructed rabbits and/or mice and/or cultured BSM cells transfected with mutated sarcoglycans.