Thesis (Ph. D.)--Case Western Reserve University, 2009. / [School of Medicine] Department of Genetics. Includes bibliographical references.

The purpose of this project is to find a mathematical model to describe the vision profile of patients after treatment for choroidal neovascularization. In this model the dependent variable is the level of vision which will be predicted by time after treatment and a number of other variables measured before treatment. A standard multiple regression analysis is used to find significant predictor variables, to investigate interactions and an appropriate transformation. To take the correlation of observations on the same patient into account a linear mixed effects model is fitted. Finally the usefulness of a nonlinear mixed effects model is investigated. / Thesis / Master of Science (MS)

No description available.

No description available.

Age-related macular degeneration (AMD) is the most common cause of vision loss in America for people over the age of 60. Due to damage to the retina, symptoms normally include blurred central vision, difficulty reading, and seeing shadows. While there is no cure for the disease, there are treatments that slow its progression and can restore vision. The treatments explored in this paper are: anti-vascular endothelial growth factor (VEGF) drugs, photodynamic therapy (PDT) and steroids. All three require invasive eye procedures that carry their own risks. The possibility of more effective treatments by combining these therapies is being tested through clinical trials. Studies of combined PDT and anti-VEGF, combined PDT and steroids, and anti-VEGF monotherapy were reviewed, comparing changes in average visual acuity, foveal thickness, and number of injections administered. PDT and anti-VEGF was concluded to be the most efficient of the three, requiring fewer injections while showing an increase in visual acuity similar to anti-VEGF monotherapy.

No description available.

Background: Systemic hypertension is a risk factor of age-related macular degeneration (AMD), a chronic inflammatory disease. Acute hypertension is caused by increased extracellular osmolarity after intake of dietary salt (NaCl). We determined in cultured human retinal pigment epithelial (RPE) cells whether high extracellular NaCl alters the gene expression of inflammasome-associated proteins, and whether autocrine/paracrine purinergic (P2) receptor signaling contributes to the NaCl-induced NLRP3 gene expression. Methodology/Principal Findings: Hyperosmolarity was induced by the addition of 100 mM NaCl or sucrose to the culture medium. Gene and protein expression levels were determined with real-time RT-PCR and Western blot analysis, respectively. IL-1β and IL-18 levels were evaluated with ELISA. Nuclear factor of activated T cell 5 (NFAT5) expression was knocked down with siRNA. High extracellular NaCl induced NLRP3 and pro-IL-1β gene expression, while the gene expression of further inflammasome-associated proteins (NLRP1, NLRP2, NLRP6, NLRP7, NLRP12, NLRC4, AIM2, ASC, procaspase-1, pro-IL-18) was not altered or below the detection threshold. The NaCl-induced NLRP3 gene expression was partially dependent on the activities of phospholipase C, IP3 receptors, protein kinase C, the serum and glucocorticoid-regulated kinase, p38 MAPK, ERK1/2, JNK, PI3K, and the transcription factors HIF-1 and NFAT5. Pannexin-dependent ATP release and P2Y1 receptor activation is required for the full induction of NLRP3 gene expression. High NaCl induced a transient increase of the NLRP3 protein level and a moderate NLRP3 inflammasome activation, as indicated by the transient increase of the cytosolic level of mature IL-1β. High NaCl also induced secretion of IL-18. High extracellular NaCl induces priming of the NLRP3 inflammasome in RPE cells, in part via P2Y1 receptor signaling. The inflammasome priming effect of NaCl suggests that high intake of dietary salt may promote local retinal inflammation implicated in the development of AMD.

Yang, Yaping. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 156-165). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.

Late-onset retinal macular degeneration (L-ORMD) is a fully penetrant autosomal dominant macular degeneration resulting from a Ser163Arg substitution in the gene encoding the protein C1QTNF5. Clinically L-ORMD results in dark adaptation delay in the fifth decade, central visual loss in the sixth decade and further progressive visual field loss in successive decades of life. Pathologically the disease results in thick sub-retinal deposits, which have a similar composition to drusen seen in AMD, retinal pigment epithelial (RPE) loss, and neuro-retinal atrophy. The function of C1QTNF5 is incompletely understood however within the eye it is expressed most strongly by the RPE cells. An in vitro model for L-ORMD was developed using human induced pluripotent stem cells (hiPSCs) derived from patients and with stem cells from patient’s unaffected siblings used as controls. The hiPSCs were differentiated to RPE (hiPSC-RPE). L-ORMD hiPSC-RPE shared baseline characteristics with sibling control hiPSC-RPE. In order to model in vivo conditions hiPSC-RPE were grown on permeable supports in human serum enriched media. Case hiPSC-RPE cell lines were found to activate the complement pathway resulting in increased deposition of the terminal complement complex (TCC) C5b-9 when compared to control hiPSC-RPE. Using depleted serum, deposition was not affected by depletion of classical and lectin pathway components but was reduced by depletion of alternative complement pathway components. Depletion of complement components C3 and C5 abolished TCC deposition. The addition of a monoclonal antibody against C5 also reduced TCC deposition. The role of complement dysregulation in L-ORMD pathogenesis was confirmed by immunostaining of L-ORMD and age-matched control human donor retinal sections. L-ORMD retinal sections displayed increased C3d and C5b-9 deposition. Using mutant and wild type-protein generated from a bacterial expression system it was found that the mutant protein was less stable than the wild-type. In addition the wild type protein formed multimers whilst the mutant was mainly monomeric. A surface plasmon resonance (SPR) study showed an increased affinity of wild-type C1QTNF5, especially in multimeric form for complement factor H (CFH), a key regulator of the alternative complement pathway when compared to mutant protein. Taken together these studies implicate dysfunction of the alternative complement pathway in L-ORMD disease mechanism and have suggested a role for C1Q TNF5 in the extracellular matrix. The studies also show that L-ORMD and AMD share a pathogenic and clinical similarities.

Age-related Macular Degeneration (AMD) is the leading cause of irreversible vision loss among elderly people in developed countries. The non-neovascular or “dry” form of AMD accounts for 85%, whereas the neovascular or “wet” accounts for 15%, of all cases. There are no effective treatments for dry AMD mainly because the molecular mechanisms that lead to the development and progression of AMD are not fully understood. Similarly, while wet AMD is being treated with antibodies against vascular endothelial growth factor (VEGF), the underlying cause that results in the development of wet AMD remains elusive. Cytosolic accumulation of nuclear-DNA (nDNA) fragments has been found to trigger inflammation and mediate the development of multiple diseases. Because inflammation plays a pivotal role in AMD pathogenesis, we thus investigated if accumulation of cytosolic nDNA also contributes to AMD. Our data show that cytosolic nDNA is enriched in macular retinal pigment epithelium (RPE) cells of AMD patients. To study the effect of cytosolic nDNA on RPE cells, we mimicked this pathology by deleting the lysosomal endonuclease Dnase2a, which is responsible for degrading DNA fragments, using CRISPR/Cas9. This resulted in cytosolic accumulation of nDNA in cultured primary human RPE cells as well as in the RPE cell line ARPE-19. Importantly, both RPE cell types with Dnase2a loss became senescent and secreted higher levels of VGEF and pro-inflammatory cytokines compared to control. These effects were mediated by the DNA sensor STING and mTOR pathway. Additionally, similar to other senescent cells, these senescent RPE cells secreted factors that acted in a paracrine manner turning otherwise healthy RPE cells into senescent cells that start secreting VEGF as well as pro-inflammatory cytokines. Finally, we found that mice with Dnase2a deletion develop features of AMD-like retinopathy, including drusen- like deposits, thickened Bruch’s membrane, RPE damage, photoreceptor atrophy, and reduced electroretinogram. The pleiotropic downstream effects of cytosolic accumulation of nDNA in RPE cells, which are consistent with the complex AMD pathology, suggest that this phenomenon contributes to the pathogenesis of AMD and thereby opens new opportunities for therapeutic interventions. / 2020-10-24T00:00:00Z