Sarcoglycan[s] are not muscle-specific: hypothetical roles.

The sarcoglycan complex is a multimember transmembrane complex interacting with other proteins to provide a mechano-signaling connection from the cytoskeleton to the extracellular matrix in myofibers. This complex plays a key role at the membrane and is crucial in maintaining sarcolemma viability in muscle fibers. Recent observations have demonstrated that in the lung this glycoprotein is associated with both alveoli and bronchioles, and that the urogenital and digestive tracts are epsilon-sarcoglycan positive. Further addressing this issue, in this work we extend our previous studies to better verify whether the sarcoglycan complex also exists in epithelial tissue. All our observations showed staining for all sarcoglycans to be a normal pattern in all tested epithelial cells. We hypothesize a key role for sarcoglycans in bidirectional signaling between cells and extracellular matrix, and an important role in the regulation of inhibitory synapses and of blood brain barrier.