Nicole E Ashpole1, Darryl R Overby2, C Ross Ethier3, W Daniel Stamer4. 1. Biomedical Engineering, Duke University, Durham, North Carolina, United States. 2. Department of Bioengineering, Imperial College London, London, United Kingdom. 3. Department of Bioengineering, Imperial College London, London, United Kingdom Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States. 4. Ophthalmology Department, Duke University, Durham, North Carolina, United States.
Abstract
PURPOSE: Endothelial nitric oxide (NO) synthase is regulated by shear stress. At elevated intraocular pressures when the Schlemm's canal (SC) begins to collapse, shear stress is comparable with that in large arteries. We investigated the relationship between NO production and shear stress in cultured human SC cells. METHODS: Schlemm's canal endothelial cells isolated from three normal and two glaucomatous human donors were seeded into Ibidi flow chambers at confluence, cultured for 7 days, and subjected to steady shear stress (0.1 or 10 dynes/cm(2)) for 6, 24, or 168 hours. Cell alignment with flow direction was monitored, and NO production was measured using 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM) and Griess reagents. Human trabecular meshwork (TM) and umbilical vein endothelial cells (HUVECs) were used as controls. RESULTS: Normal SC strains aligned with the direction of flow by 7 days. Comparing 0.1 vs. 10 dynes/cm(2), NO levels increased by 82% at 24 hours and 8-fold after 7 days by DAF-FM, and similar results were obtained with Griess reagent. Shear responses by SC cells at 24 hours were comparable with HUVECs, and greater than TM cells, which appeared shear-insensitive. Nitric oxide production by SC cells was detectable as early as 6 hours and was inhibited by 100 μM nitro-L-arginine methyl ester. Two glaucomatous SC cell strains were either unresponsive or lifted from the plate in the face of shear. CONCLUSIONS: Shear stress triggers NO production in human SC cells, similar to other vascular endothelia. Increased shear stress and NO production during SC collapse at elevated intraocular pressures may in part mediate IOP homeostasis. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
PURPOSE: Endothelial nitric oxide (NO) synthase is regulated by shear stress. At elevated intraocular pressures when the Schlemm's canal (SC) begins to collapse, shear stress is comparable with that in large arteries. We investigated the relationship between NO production and shear stress in cultured human SC cells. METHODS: Schlemm's canal endothelial cells isolated from three normal and two glaucomatoushuman donors were seeded into Ibidi flow chambers at confluence, cultured for 7 days, and subjected to steady shear stress (0.1 or 10 dynes/cm(2)) for 6, 24, or 168 hours. Cell alignment with flow direction was monitored, and NO production was measured using 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM) and Griess reagents. Human trabecular meshwork (TM) and umbilical vein endothelial cells (HUVECs) were used as controls. RESULTS: Normal SC strains aligned with the direction of flow by 7 days. Comparing 0.1 vs. 10 dynes/cm(2), NO levels increased by 82% at 24 hours and 8-fold after 7 days by DAF-FM, and similar results were obtained with Griess reagent. Shear responses by SC cells at 24 hours were comparable with HUVECs, and greater than TM cells, which appeared shear-insensitive. Nitric oxide production by SC cells was detectable as early as 6 hours and was inhibited by 100 μM nitro-L-arginine methyl ester. Two glaucomatous SC cell strains were either unresponsive or lifted from the plate in the face of shear. CONCLUSIONS: Shear stress triggers NO production in human SC cells, similar to other vascular endothelia. Increased shear stress and NO production during SC collapse at elevated intraocular pressures may in part mediate IOP homeostasis. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
Authors: Dan Predescu; Sanda Predescu; Jun Shimizu; Kayo Miyawaki-Shimizu; Asrar B Malik Journal: Am J Physiol Lung Cell Mol Physiol Date: 2005-09 Impact factor: 5.464
Authors: Joanne F J Logan; Usha Chakravarthy; Anne E Hughes; Chris C Patterson; Jonathan A Jackson; Simon J A Rankin Journal: Invest Ophthalmol Vis Sci Date: 2005-09 Impact factor: 4.799
Authors: Caroline Cheng; Rien van Haperen; Monique de Waard; Luc C A van Damme; Dennie Tempel; Laurens Hanemaaijer; Gert W A van Cappellen; Joop Bos; Cornelis J Slager; Dirk J Duncker; Anton F W van der Steen; Rini de Crom; Rob Krams Journal: Blood Date: 2005-08-16 Impact factor: 22.113
Authors: M Noris; M Morigi; R Donadelli; S Aiello; M Foppolo; M Todeschini; S Orisio; G Remuzzi; A Remuzzi Journal: Circ Res Date: 1995-04 Impact factor: 17.367
Authors: Jason Y H Chang; W Daniel Stamer; Jacques Bertrand; A Thomas Read; Catherine M Marando; C Ross Ethier; Darryl R Overby Journal: Am J Physiol Cell Physiol Date: 2015-06-03 Impact factor: 4.249
Authors: Heather M Schmitt; William M Johnson; Inas F Aboobakar; Shelby Strickland; María Gomez-Caraballo; Megan Parker; Laura Finnegan; David L Corcoran; Nikolai P Skiba; R Rand Allingham; Michael A Hauser; W Daniel Stamer Journal: Hum Mol Genet Date: 2020-07-29 Impact factor: 6.150
Authors: Louis R Pasquale; Akiko Hanyuda; Ai Ren; Michael Giovingo; Scott H Greenstein; Clara Cousins; Thomas Patrianakos; Angelo P Tanna; Christopher Wanderling; William Norkett; Janey L Wiggs; Kelsey Green; Jae H Kang; Paul A Knepper Journal: Invest Ophthalmol Vis Sci Date: 2015-11 Impact factor: 4.799
Authors: Jae H Kang; Walter C Willett; Bernard A Rosner; Emmanuel Buys; Janey L Wiggs; Louis R Pasquale Journal: JAMA Ophthalmol Date: 2016-03 Impact factor: 7.389