Chao Wang1,2,3, Yalong Dang1, Ralitsa T Loewen1, Susannah Waxman1, Priyal Shah1, Xiaobo Xia2, Nils A Loewen4,5. 1. Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA. 2. Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China. 3. The Third Xiangya Hospital of Central South University, Changsha, Hunan, China. 4. Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA. loewen.nils@gmail.com. 5. Department of Ophthalmology, University of Pittsburgh, 203 Lothrop St, Pittsburgh, PA, 15213, USA. loewen.nils@gmail.com.
Abstract
PURPOSE: Dysfunction of the trabecular meshwork (TM) in pigmentary glaucoma contributes to increased aqueous humor outflow resistance and intraocular pressure. In this study, we investigated the effect of pigment dispersion on trabecular meshwork cells. METHODS: Porcine TM cells from ab interno trabeculectomy specimens were exposed to pigment dispersion, then, analyzed for changes in morphology, immunostaining, and ultrastructure. Their abilities to phagocytose migrate, and contraction was quantified. An expression microarray, using 23,937 probes, and a pathway analysis were performed. RESULTS: Stress fiber formation was increased in the pigment dispersion group (P) (60.1 ± 0.3%, n = 10) compared to control (C) (38.4 ± 2.5%, n = 11, p < 0.001). Phagocytosis declined (number of cells with microspheres in P = 37.0 ± 1.1% and in C = 68.7 ± 1.3%, n = 3, p < 0.001) and migration was reduced after 6 h (cells within the visual field over 6 h in P = 28.0.1 ± 2.3 (n = 12) and in C = 40.6 ± 3.3 (n = 13), p < 0.01). Pigment induced contraction at 24 h onwards (p < 0.01). Microarray analysis revealed that Rho signaling was central to these responses. CONCLUSION: Exposure of TM cells to pigment dispersion resulted in reduced phagocytosis and migration, as well as increased stress fiber formation and cell contraction. The Rho signaling pathway played a central and early role, suggesting that its inhibitors could be used as a specific intervention in treatment of pigmentary glaucoma.
PURPOSE: Dysfunction of the trabecular meshwork (TM) in pigmentary glaucoma contributes to increased aqueous humor outflow resistance and intraocular pressure. In this study, we investigated the effect of pigment dispersion on trabecular meshwork cells. METHODS: Porcine TM cells from ab interno trabeculectomy specimens were exposed to pigment dispersion, then, analyzed for changes in morphology, immunostaining, and ultrastructure. Their abilities to phagocytose migrate, and contraction was quantified. An expression microarray, using 23,937 probes, and a pathway analysis were performed. RESULTS:Stress fiber formation was increased in the pigment dispersion group (P) (60.1 ± 0.3%, n = 10) compared to control (C) (38.4 ± 2.5%, n = 11, p < 0.001). Phagocytosis declined (number of cells with microspheres in P = 37.0 ± 1.1% and in C = 68.7 ± 1.3%, n = 3, p < 0.001) and migration was reduced after 6 h (cells within the visual field over 6 h in P = 28.0.1 ± 2.3 (n = 12) and in C = 40.6 ± 3.3 (n = 13), p < 0.01). Pigment induced contraction at 24 h onwards (p < 0.01). Microarray analysis revealed that Rho signaling was central to these responses. CONCLUSION: Exposure of TM cells to pigment dispersion resulted in reduced phagocytosis and migration, as well as increased stress fiber formation and cell contraction. The Rho signaling pathway played a central and early role, suggesting that its inhibitors could be used as a specific intervention in treatment of pigmentary glaucoma.
Authors: Weiming Mao; Tara Tovar-Vidales; Thomas Yorio; Robert J Wordinger; Abbot F Clark Journal: Invest Ophthalmol Vis Sci Date: 2011-10-17 Impact factor: 4.799
Authors: Yasmin Siddiqui; Richard D Ten Hulzen; J Douglas Cameron; David O Hodge; Douglas H Johnson Journal: Am J Ophthalmol Date: 2003-06 Impact factor: 5.258
Authors: Ralitsa T Loewen; Eric N Brown; Pritha Roy; Joel S Schuman; Ian A Sigal; Nils A Loewen Journal: PLoS One Date: 2016-03-21 Impact factor: 3.240