Abstract
Abstract: :
Purpose: The majority of resistance to outflow of aqueous humor resides at or near the inner wall of Schlemm's canal (SC). Some of the proteins that contribute to the generation of resistance likely participate in junctional complexes between SC cells. The purpose of the present study was to examine the expression of vascular endothelial (VE)-cadherin (also known as cadherin-5), a protein that contributes significantly to the formation of junctional complexes and the control of permeability of vascular endothelium. Methods: Using reverse-transcription followed by polymerase chain reaction, the expression of VE-cadherin mRNA was examined in dissected trabecular meshwork/SC tissue and SC cells isolated specifically from human cadaveric eyes. VE cadherin protein expression was determined in frozen sections of human anterior chambers, excised flaps containing SC inner wall and SC cells in culture using monoclonal antibodies raised to a human VE-cadherin fusion protein. Results: Both VE-cadherin messenger RNA and protein was detected in preparations containing SC cells. VE-cadherin protein colocalized specifically with filamentous actin circumferentially to cell borders. Conclusions: VE-cadherin expression in SC demonstrates that SC cells are vascular in origin and contain a junctional protein likely involved in restricting fluid flow across the inner wall of SC.
Keywords: 339 cell adhesions/cell junctions • 474 microscopy: light/fluorescence/immunohistochemistry • 503 outflow: trabecular meshwork