L Zhou1, E J Higginbotham, B Y Yue. 1. Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, College of Medicine 60612, USA.
Abstract
PURPOSE: Fibronectin, laminin and collagen type I are important extracellular matrix products of trabecular meshwork cells. This study was performed to examine the effects of ascorbic acid, a significant component in the aqueous humor, on the levels of these proteins in trabecular meshwork cells maintained in organ culture. METHODS: The anterior segment of freshly enucleated bovine eyes was perfused in a modified organ culture system. Three cultures were set up simultaneously. One received serum-free medium containing 100 micrograms/ml of ascorbic acid, one received 250 micrograms/ml of ascorbic acid and one served as a control. After 72 h, the tissues were processed for paraffin sections and immunostaining was conducted using an avidin-biotin-peroxidase complex method. Western blot and dot blot assays were performed on tissue extracts. RESULTS: Compared with the controls, the staining for fibronectin and laminin was markedly enhanced in trabecular meshwork tissues treated with both concentrations of ascorbic acid. Increased collagen type I production by trabecular meshwork cells was also demonstrated in the presence of ascorbic acid. Western blot and dot blot results confirmed the immunostaining findings. CONCLUSIONS: Ascorbic acid promotes production of fibronectin, laminin and collagen type I by trabecular meshwork cells. The organ culture results are consistent with those obtained previously from tissue culture studies.
PURPOSE:Fibronectin, laminin and collagen type I are important extracellular matrix products of trabecular meshwork cells. This study was performed to examine the effects of ascorbic acid, a significant component in the aqueous humor, on the levels of these proteins in trabecular meshwork cells maintained in organ culture. METHODS: The anterior segment of freshly enucleated bovine eyes was perfused in a modified organ culture system. Three cultures were set up simultaneously. One received serum-free medium containing 100 micrograms/ml of ascorbic acid, one received 250 micrograms/ml of ascorbic acid and one served as a control. After 72 h, the tissues were processed for paraffin sections and immunostaining was conducted using an avidin-biotin-peroxidase complex method. Western blot and dot blot assays were performed on tissue extracts. RESULTS: Compared with the controls, the staining for fibronectin and laminin was markedly enhanced in trabecular meshwork tissues treated with both concentrations of ascorbic acid. Increased collagen type I production by trabecular meshwork cells was also demonstrated in the presence of ascorbic acid. Western blot and dot blot results confirmed the immunostaining findings. CONCLUSIONS:Ascorbic acid promotes production of fibronectin, laminin and collagen type I by trabecular meshwork cells. The organ culture results are consistent with those obtained previously from tissue culture studies.
Authors: Pascal Joly; Georg N Duda; Martin Schöne; Petra B Welzel; Uwe Freudenberg; Carsten Werner; Ansgar Petersen Journal: PLoS One Date: 2013-09-05 Impact factor: 3.240