Date

9-2013

Document Type

Dissertation

Degree Name

Ph.D.

Department

Dept. of Biochemistry and Molecular Biology

Institution

Oregon Health & Science University

Abstract

A compromised regulation of intraocular pressure, or IOP, is the primary risk factor for primary open angle glaucoma (POAG). A prominent feature of the disease is cellular loss. To establish a greater level of standardization of cell loss in our experimental anterior segments, we developed a cell depletion model using saponin and partially denuded trabecular meshwork (TM) areas to mimic the situation in glaucoma. With this model, we developed transplantable differentiated TM-like cells from induced pluripotent stem cells (iPSCs), and utilized these cells in an ex vivo perfusion system for functional testing of TM in anterior segments. This included two essential TM functional end points: 1) IOP homeostasis; and 2) phagocytosis. Subsequent to transplantation of the unique TM-like cells to denuded TM areas, we tested them for competency of function in which the modified stem cells were required to be comparable to endogenous TM cells in intact anterior segments. Our monitoring of the differentiation of iPSCs to TM-like cells was facilitated by the expression of biomarkers as well as the loss of pluripotency factors, and evaluated by confocal microscopy, Western immunoblotting and quantitative RT-PCR. The transplanted labeled TM-like cells were integrated into the TM at all levels. Transplanting these TM-like cells and subjecting them to a high pressure challenge showed the restoration of IOP homeostatic response. Additionally, a xii phagocytic challenge to these TM-like cells with zymosan particles also resulted in responses comparable to those of endogenous TM cells. Establishing a connection between TM cell loss and tissue functionality is novel. In addition, replacing the lost cells in glaucomatous eyes by using iPSCs in the TM is a novel treatment strategy that has not been previously attempted in trabecular meshwork, and shows considerable promise as an alternative treatment for glaucoma.

Identifier

doi:10.6083/M4GB22DK

School

School of Medicine

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