|
|
||||||||
1From the Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, Kentucky; the 2Department of Ophthalmology, Dalhousie University, Halifax, Nova Scotia, Canada; 3Pharmacia Corporation, Chesterfield, Missouri; and the 4Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri.
PURPOSE. To determine whether retinal glial cells exhibit an activated phenotype in glaucomatous human eyes and whether the mitogen-activated protein kinases (MAPKs) are associated with glial activation in glaucoma.
METHODS. Activated phenotypes of retinal macroglia (astrocytes and Müller cells) and microglia were identified by morphologic assessment and immunostaining for the cell markers glial fibrillary acidic protein (GFAP) and HLA-DR, respectively, in 30 eyes obtained from glaucomatous donor eyes in comparison with normal control eyes from 20 age-matched donors. Cellular localization of the activated forms of MAPKs, including extracellular signal-regulated kinases (ERK), c-Jun amino(N)-terminal kinase (JNK), and p38, were studied in the retina of these eyes by immunoperoxidase staining and double immunofluorescence labeling with phosphorylation site-specific antibodies.
RESULTS. Retinal astrocytes and Müller cells exhibited a hypertrophic morphology and increased immunostaining for GFAP in the glaucomatous retina. Although an increase was detectable in the number and size of cells positive for HLA-DR immunostaining in the glaucomatous retina compared with the control retina, microglial activation was not as prominent or widespread as the macroglial activation detected in the same eyes. The intensity of immunostaining and the number of immunostained cells for the activated MAPKs were greater in retina sections from glaucomatous eyes than in control eyes, being most prominent for phospho-ERK. Double immunofluorescence labeling demonstrated that the increased retinal immunostaining for phospho-ERK was predominantly, but not exclusively, localized to glial cells, whereas, the immunostaining for phospho-JNK or phospho-p38 was mainly associated with nonglial cells.
CONCLUSIONS. These findings provide evidence that retinal glial cells undergo activation in the glaucomatous human retina. A prominent and persistent activation of ERK in activated glial cells suggests that this signaling pathway is probably associated with the induction and/or maintenance of the activated glial phenotype in glaucoma. Because MAPKs are involved in determination of ultimate cell fate, their differential activity in neuronal and activated glial cells in the glaucomatous retina may be associated, in part, with the differential susceptibility of these cell types to glaucomatous injury.
This article has been cited by other articles:
![]() |
X. Yang, C. Luo, J. Cai, W. M. Pierce, and G. Tezel Phosphorylation-Dependent Interaction with 14-3-3 in the Regulation of Bad Trafficking in Retinal Ganglion Cells Invest. Ophthalmol. Vis. Sci., June 1, 2008; 49(6): 2483 - 2494. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Bosco, D. M. Inman, M. R. Steele, G. Wu, I. Soto, N. Marsh-Armstrong, W. C. Hubbard, D. J. Calkins, P. J. Horner, and M. L. Vetter Reduced Retina Microglial Activation and Improved Optic Nerve Integrity with Minocycline Treatment in the DBA/2J Mouse Model of Glaucoma Invest. Ophthalmol. Vis. Sci., April 1, 2008; 49(4): 1437 - 1446. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Yang, H. A. Quigley, M. E. Pease, Y. Yang, J. Qian, D. Valenta, and D. J. Zack Changes in Gene Expression in Experimental Glaucoma and Optic Nerve Transection: The Equilibrium between Protective and Detrimental Mechanisms Invest. Ophthalmol. Vis. Sci., December 1, 2007; 48(12): 5539 - 5548. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. F Schmidt, O. A Agapova, P. Yang, P. L Kaufman, and M R. Hernandez Expression of ephrinB1 and its receptor in glaucomatous optic neuropathy Br. J. Ophthalmol., September 1, 2007; 91(9): 1219 - 1224. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Tezel, C. Luo, and X. Yang Accelerated Aging in Glaucoma: Immunohistochemical Assessment of Advanced Glycation End Products in the Human Retina and Optic Nerve Head Invest. Ophthalmol. Vis. Sci., March 1, 2007; 48(3): 1201 - 1211. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Tezel, X. Yang, C. Luo, Y. Peng, S. L. Sun, and D. Sun Mechanisms of Immune System Activation in Glaucoma: Oxidative Stress-Stimulated Antigen Presentation by the Retina and Optic Nerve Head Glia Invest. Ophthalmol. Vis. Sci., February 1, 2007; 48(2): 705 - 714. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Nakazawa, C. Nakazawa, A. Matsubara, K. Noda, T. Hisatomi, H. She, N. Michaud, A. Hafezi-Moghadam, J. W. Miller, and L. I. Benowitz Tumor Necrosis Factor-{alpha} Mediates Oligodendrocyte Death and Delayed Retinal Ganglion Cell Loss in a Mouse Model of Glaucoma J. Neurosci., December 6, 2006; 26(49): 12633 - 12641. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Liu, Q. Huang, J. Higdon, W. Liu, T. Xie, T. Yamashita, K. Cheon, C. Cheng, and J. Zuo Distinct gene expression profiles and reduced JNK signaling in retinitis pigmentosa caused by RP1 mutations Hum. Mol. Genet., October 1, 2005; 14(19): 2945 - 2958. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Tezel, X. Yang, and J. Cai Proteomic Identification of Oxidatively Modified Retinal Proteins in a Chronic Pressure-Induced Rat Model of Glaucoma Invest. Ophthalmol. Vis. Sci., September 1, 2005; 46(9): 3177 - 3187. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Di Girolamo, M. Coroneo, and D. Wakefield Epidermal Growth Factor Receptor Signaling Is Partially Responsible for the Increased Matrix Metalloproteinase-1 Expression in Ocular Epithelial Cells after UVB Radiation Am. J. Pathol., August 1, 2005; 167(2): 489 - 503. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Kashiwagi, Y. Iizuka, Y. Tanaka, M. Araie, Y. Suzuki, and S. Tsukahara Molecular and Cellular Reactions of Retinal Ganglion Cells and Retinal Glial Cells under Centrifugal Force Loading Invest. Ophthalmol. Vis. Sci., October 1, 2004; 45(10): 3778 - 3786. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Tezel and M. B. Wax Hypoxia-Inducible Factor 1{alpha} in the Glaucomatous Retina and Optic Nerve Head Arch Ophthalmol, September 1, 2004; 122(9): 1348 - 1356. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. A. El-Asrar, L. Dralands, L. Missotten, I. A. Al-Jadaan, and K. Geboes Expression of Apoptosis Markers in the Retinas of Human Subjects with Diabetes Invest. Ophthalmol. Vis. Sci., August 1, 2004; 45(8): 2760 - 2766. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |