The trabecular meshwork (TM) is believed to be a major site for the regulation of the aqueous outflow. Residing in this tissue are TM cells that are essential for the maintenance of normal outflow. Aberrations of cell integrity may be a key step toward obstruction of the aqueous outflow, intraocular pressure elevations, and glaucomatous conditions. Along with the cells, extracellular matrix (ECM) materials such as fibronectin, laminin, and collagens are also thought to be important for normal functioning of the TM. We propose, in this application, to examine a family of receptors for ECM proteins, the integrins, and the cell-matrix interactions in the human TM. The integrins are known to interact with cytoskeletal proteins, mediate cell attachment, and influence a variety of cellular activities. They are also crucial in the determination of growth, morphology, metabolism, and differentiation of cells. In the TM system, cells line the trabecular beams that are made up of connective tissues. The TM cells in vivo are continually subjected to flows of the aqueous humor and changes in the intraocular pressure. The lining integrity against stress is critically dependent on the adhesion of TM cells to the matrices through integrin receptors. Disruption in the adhesion of TM cells to the ECM would conceivably lead to cell loss, denudation of the beams, and pathologic consequences. Characterization of the integrins and elucidation of the cell-matrix interactions in the TM are therefore of fundamental significance. We have initiated investigations on integrins and have found that the integrin repertoire in cultured TM cells is similar to that in tissues. We will further our efforts to evaluate the roles of integrins in adhesion of cultured TM cells to the ECM and to determine the integrin-mediated signaling pathways by immunoprecipitation, immunofluorescence staining and other methods. Activators and inhibitors will be used to define further the potential signaling mechanisms involved. We propose to dissect systematically the information transduced by cell-ECM interactions using the in vitro human TM cultures coupled with defined matrices. The effects of individual ECM substrata on the integrin distribution and biologic characteristics of TM cells will be assessed by cell biology and molecular biology techniques. To probe the functional roles of integrins, human TM cells will be transfected to result in either enhanced or suppressed expression of specific integrins. The effects of gene alterations will be analyzed. In addition, the integrin distribution and expression in conditions that are known to induce ECM changes in TM cells, such as after phagocytic challenges and after glucocorticoid treatments, will be examined. Modulation in the integrins will be correlated with the ECM changes. The effects of growth factors on the production and expression of fibronectin, laminin, collagen, and integrins by TM cells in both cell culture and organ culture systems will also be investigated. Protocols of immunohistochemical staining, and dot blot, Western blot and Northern blot analyses will be followed. Our goal is to increase the understanding of the biologic characteristics of healthy as well as experimentally-altered TM cells, particularly with regard to the dynamics and control mechanisms involved in the cell-matrix interactions in the TM. This information will assist in uncovering the pathogenic processes of glaucomas.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY005628-14
Application #
2888175
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1984-12-01
Project End
2000-07-31
Budget Start
1999-08-01
Budget End
2000-07-31
Support Year
14
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Illinois at Chicago
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
121911077
City
Chicago
State
IL
Country
United States
Zip Code
60612
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Qiu, Ye; Shen, Xiang; Shyam, Rajalekshmy et al. (2014) Cellular processing of myocilin. PLoS One 9:e92845
Ying, Hongyu; Shen, Xiang; Yue, Beatrice Y J T (2012) Establishment of inducible wild type and mutant myocilin-GFP-expressing RGC5 cell lines. PLoS One 7:e47307
Shen, Xiang; Ying, Hongyu; Yue, Beatrice Y J T (2012) Wnt activation by wild type and mutant myocilin in cultured human trabecular meshwork cells. PLoS One 7:e44902
Ying, Hongyu; Yue, Beatrice Y J T (2012) Cellular and molecular biology of optineurin. Int Rev Cell Mol Biol 294:223-58
Shen, Xiang; Ying, Hongyu; Qiu, Ye et al. (2011) Processing of optineurin in neuronal cells. J Biol Chem 286:3618-29
Yue, Beatrice Y J T (2011) Myocilin and Optineurin: Differential Characteristics and Functional Consequences. Taiwan J Ophthalmol 1:6-11
Ying, Hongyu; Shen, Xiang; Park, BumChan et al. (2010) Posttranslational modifications, localization, and protein interactions of optineurin, the product of a glaucoma gene. PLoS One 5:e9168
Park, BumChan; Ying, Hongyu; Shen, Xiang et al. (2010) Impairment of protein trafficking upon overexpression and mutation of optineurin. PLoS One 5:e11547
Knepper, Paul A; Samples, John R; Yue, Beatrice Yjt (2010) Biomarkers of primary open-angle glaucoma. Expert Rev Ophthalmol 5:731-742

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