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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.

Orientador: Márcio Benchimol Barros / Banca: Andrey Ivanov / Banca: José Fernander Weber / Resumo: Esta pesquisa possui o intento de investigar a noção de décadence na filosofia Nitzschiana, especificamente em sua obra tardia, uma vez que é neste período de sua filosofia que o conceito possui maior ocorrência. Para tal tarefa, buscase primeiro compreender qual a relação entre a fisiologia e o conceito em questão, só depois então passaremos a analisar o processo de décadence, que teve início com a razão socrática e posteriormente sua continuação com o cristianismo, até culminar na modernidade, onde Nietzsche aponta a arte Wagneriana como a arte da décadence. Abordaremos as obras: Além do Bem e do mal, Assim falou Zaratustra, Anticristo, Crepúsculo dos Ídolos, Ecce Homo, O Caso Wagner e os Fragmentos Póstumos, todas escritas entre o ano de 1883 a 1888. Pensamos que o estudo do conceito se torna indispensável para uma melhor compreensão da filosofia tardia de Nietzsche, principalmente para entender a crítica dos valores que ele conduz contra a sociedade moderna ocidental, sendo assim, este trabalho também contribui com a pesquisa Nietzsche. / Abstract: This research intends to investigate the notion of décadence in Nietzsche 's philosophy, specificalli in his late work, since it occurrence. For this task, we firts try to understand the relation between physiology and the concept approached, then we Will analyze the process of décadence, which began with the Socratic reason and then its continuation with Christianity, culminating in modernity where Nietzsche points to Wagnerian art as the décadence's art. We will discuss the works: Beyond Good na Evil, Thus Spoke Zarathustra, Antchrist, Twilight of Idols, Ecce Homo, The Wagner Case and The Posthumos Fragments, all written between the year 1883 and 1888. We think that the study of de concept becomes indispensable for a better understanding of Nietzsche's late philosophy, especially in ordem to understand the critique of values that He conducts against modern western society, therefore this work also contributes to the Nietzsche research. / Mestre

Age-related macular degeneration (AMD) is the leading cause of blindness in the western world for people over 60 years of age. The most severe pathological event of AMD is choroidal neovascularization (CNV), the process of new vessel formation emerging from the choroid. The new vessels extend into the normally avascular photoreceptor cell layer, where they leak fluid and cause photoreceptor cell death. CNV is thought to be initiated by hypoxia and chronic inflammation, which occur due to abnormal, age-related changes within the retinal pigmented epithelium (RPE). These events cause increased expression of the angiogenic protein vascular endothelial growth factor (VEGF) via hypoxiainducible factor-1 (HIF-1), a transcription factor that is vital in regulation of cellular responses to hypoxic and inflammatory conditions. Increased VEGF signaling stimulates proliferation and migration of vascular endothelial cells and facilitates the neovascular process. To target the early pathological events that lead to CNV, we have engineered a novel gene therapy vector that uses HIF-1 regulation to stimulate production of an angiostatic protein, endostatin from the RPE. The purpose of this study was to characterize the activity of our hypoxiaregulated, RPE-specific promoter in vitro, and investigate the effects of regulated endostatin expression, driven by our regulated promoter, on CNV in a mousemodel. We found the regulated promoter construct has robust activity in vitro only in RPE cells, and is conditionally responsive in hypoxic conditions. / In the laserinduced CNV model, CNV area was 80% smaller (P<0.0001) in eyes treated with the hypoxia-regulated, RPE-specific endostatin vector than in untreated eyes. CNV area was equally reduced in eyes treated with an unregulated endostatin vector (CMV-endostatin). However, less endostatin protein was detected in eyes treated with the regulated vector. Since it is unknown whether broad and constitutive endostatin expression will have damaging effects within the retina, it may be safer to limit its expression to pathological conditions. We have demonstrated that local, hypoxia-regulated expression of endostatin can effectively inhibit CNV, and thus, offers the further possibility of a prophylactic treatment for neovascular AMD. / by George Wesley Tyler Smith. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

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

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The following dissertation herein discusses the role of axonal protein synthesis in Aβ1-42-dependent neurodegeneration, which has important implications in AD pathogenesis. In Part 1, I provide a brief introduction to relevant topics including neurodegeneration and axonal protein synthesis. In Part 2, I discuss findings that we published in 2014 describing a mechanism by which axonal exposure to Aβ1-42 induces cell death via axonal synthesis and retrograde transport of a transcription factor, ATF4. In Part 3, I discuss a follow-up project that I conducted independently, which is not yet published but is in preparation for submission describing the immediate effect of Aβ1-42 on axonal protein synthesis, which mediates the downstream axonal ATF4 signaling events described in Part 2. In Part 4, I discuss the key findings from these two projects including their significance and potential future directions. In the Appendix, I provide details regarding experimental methods and statistical analyses performed in Part 3.

This thesis characterises the cortical pattern of degeneration in progressive supranuclear palsy (PSP) and its consequences. Global atrophy was first examined using a recently developed staging scheme in pathologically-proven PSP cases compared with other tauopathies: gross atrophy was not observed in PSP. Quantification of regional volume loss throughout the brain was then used to determine the magnitude of more focal tissue atrophy in PSP, cortical dysfunction was investigated by measuring cerebral blood flow (CBF) changes, and several cortical cellular pathologies were analysed. Any changes observed were related to each other and clinical assessments of motor, cognitive and behavioural abnormalities. At mid-stage PSP, frontal and subcortical atrophy related to decreased CBF in the frontal cortex and cognitive decline. Parietocerebellar CBF increases were also identified (related to frontal CBF deficits) and related to motor and non-motor deficits. By end-stage PSP, focal atrophy had advanced from frontal and subcortical structures to include atrophy in the parietal lobe. Parietal lobe atrophy related to behavioural abnormalities. Histopathological analysis at end-stage revealed that the cortical atrophy and cell loss does not relate to tau deposition. The focal cortical cell loss related exclusively to motor deficits whilst the more widespread cortical tau deposition related to cognitive and behavioural impairments. Both the tau deposition and these non-motor impairments increased in severity over time. The results show that frontal atrophy and dysfunction occurs rapidly and early in PSP and relate to increasing cognitive deficits. Such deficits appear to cause compensatory CBF enhancement in parietocerebellar regions which then also undergo rapid and severe neurodegeneration. These later changes occur in concert with the more classic PSP symptoms, such as oculomotor features. Throughout the disease, the progressive increase in frontotemporal tau deposition contributes to cognitive and behavioural deficits which become most marked late in the disease. The findings strongly suggest that progressive clinical dysfunction in PSP is directly related to progressive cortical degeneration. Cortical degeneration appears to occur in two independent functional networks. Increased CBF in PSP may be a useful early indicator for future neurodegeneration, although the cellular mechanism leading to cell death requires further investigation.