Project description:This study reports on the generation of a transgenic mouse which is characterized by early-onset angle-closure glaucoma. The phenotype is due to the transgene insertion site which is proximal to the genes encoding AP-2 and AP-2, two proteins present in the retina and corneal epithelium. This leads to a reduction in AP-2 levels, which is likely to are responsible for the glaucomatous phenotype. Here we provide paired-end raw DNA-Seq reads of the transgenic mouse genome.
Project description:We generated 6 transgenic lines with insertion of an expression plasmid for the R883/M xanthine dehydrogenase (XDH) mutant protein. Approximately 20% of the animals deriving from one of the transgenic lines show ocular abnormalities and an increase in intra-ocular pressure which are consistent with glaucoma. The observed pathologic phenotype is not due to expression of the transgene, but rather the consequence of the transgene insertion site, which has been defined by genome sequencing. The insertion site maps to chromosome 1qA3 in close proximity to the loci encoding AP-2β and AP-2δ, two proteins expressed in the eye. The insertion leads to a reduction in AP-2β and AP-2δ levels. Down-regulation of AP-2β expression is likely to be responsible for the pathologic phenotype, as conditional deletion of the Tfap2b gene in the neural crest has recently been shown to cause defective development of the eye anterior segment and early-onset glaucoma. In these conditional knock-out and our transgenic mice, the morphological/histological features of the glaucomatous pathology are surprisingly similar. Our transgenic mouse represents a model of angle-closure glaucoma and a useful tool for the study of the pathogenesis and the development of innovative therapeutic strategies.
Project description:The apolipoprotein E4 (APOE4) allele is associated with an increased risk of Alzheimer’s disease and a decreased risk of glaucoma, but the underlying mechanisms remain poorly understood. Here we find that in two mouse glaucoma models and in human glaucomatous retinas, microglia transition to a neurodegenerative (MGnD) phenotype characterized by upregulation of Apoe and Lgals3 (Galectin-3). Mice in which Apoe was targeted in microglia or carrying the human APOE4 allele were protected from retinal ganglion cell (RGC) loss despite elevated intraocular pressure (IOP). Similar to Apoe–/– retinal microglia, APOE4 microglia did not upregulate MGnD genes, including Lgals3, following IOP elevation. Genetic and pharmacologic targeting of Galectin-3 ameliorated RGC degeneration, and Galectin-3 expression was attenuated in human APOE4 glaucoma samples. These results demonstrate that impaired activation of APOE4 microglia is protective in glaucoma, and that the APOE-Galectin-3 signaling pathway can be targeted to treat this blinding disease.
Project description:To better understand the molecular changes in the aqueous humor (AH) content with glaucoma, we analyzed the microRNA (miRNA) profiles of AH samples from patients with Primary Open Angle Glaucoma (POAG) and Exfoliation Glaucoma (XFG) compared to non-glaucoma controls.
Project description:Dogs frequently develop glaucoma, a disease that leads to vision loss due to loss of retinal ganglion cells and degeneration of axons within the optic nerve. We used Affymetrix Gene chips to characterize transcriptional changes between healthy and glaucomatous retinas. These data describe gene expression changes in the canine retina with glaucoma. RNA was isolated from the retinas of 5 dogs with advanced glaucoma and from 5 normal individuals.
Project description:Glaucoma, a multifactorial neurodegenerative disease characterized by progressive loss of retinal ganglion cells and their axons in the optic nerve, is a leading cause of irreversible vision loss. Intraocular pressure (IOP) is a risk factor for axonal damage, which initially occurs at the optic nerve head (ONH). Complex cellular and molecular mechanisms involved in the pathogenesis of glaucomatous optic neuropathy remain unclear. Here we define early molecular events in the ONH in an inherited large animal glaucoma model in which ONH structure resembles that of humans. Gene expression profiling of ONH tissues from rigorously phenotyped feline subjects with early-stage glaucoma and precisely age-matched controls was performed by RNA-sequencing (RNA-seq) analysis and complementary bioinformatic approaches applied to identify molecular processes and pathways of interest. Immunolabeling supported RNA-seq findings while providing cell-, region-, and disease stage–specific context in the ONH in situ. Transcriptomic evidence for cell proliferation and immune/inflammatory responses is identifiable in early glaucoma, soon after IOP elevation and prior to morphologically detectable axon loss, in this large animal model. In particular, proliferation of microglia and oligodendrocyte precursor cells is a prominent feature of early-stage, but not chronic, glaucoma. ONH microgliosis is a consistent hallmark in both early and chronic stages of glaucoma. Molecular pathways and cell type–specific responses strongly implicate toll-like receptor and NF-κB signaling in early glaucoma pathophysiology. The current study provides critical insights into molecular pathways, highly dependent on cell type and sub-region in the ONH even prior to irreversible axon degeneration in glaucoma.
Project description:The apolipoprotein E4 (APOE4) allele is associated with an increased risk of Alzheimer’s disease and a decreased risk of glaucoma, but the underlying mechanisms remain poorly understood. Here we find that in two mouse glaucoma models and in human glaucomatous retinas, microglia transition to a neurodegenerative (MGnD) phenotype characterized by upregulation of Apoe and Lgals3 (Galectin-3). Mice in which Apoe was targeted in microglia or carrying the human APOE4 allele were protected from retinal ganglion cell (RGC) loss despite elevated intraocular pressure (IOP). Similar to Apoe–/– retinal microglia, APOE4 microglia did not upregulate MGnD genes, including Lgals3, following IOP elevation. Genetic and pharmacologic targeting of Galectin-3 ameliorated RGC degeneration, and Galectin-3 expression was attenuated in human APOE4 glaucoma samples. These results demonstrate that impaired activation of APOE4 microglia is protective in glaucoma, and that the APOE-Galectin-3 signaling pathway can be targeted to treat this blinding disease.
Project description:Goals of the study: 1. Assess the gene expression profile in rat RGC after experimental IOP elevation to elucidate the molecular mechanisms of RGC death. 2. Identify potentially novel genes and pathways that may contribute to RGC death in glaucoma. Background: Glaucoma is a neurodegenerative disease characterized by the slow, progressive degeneration of RGC. Elevated IOP is the biggest risk factor for developing glaucoma, loss of RGC and optic nerve atrophy. The pathophysiology of glaucomatous neurodegeneration is not fully understood. It is now clear that RGC die by apoptosis in glaucoma. However, what triggers the apoptosis is still unknown. So far, several gene expression studies have been performed on the retina as a whole. These studies revealed up and downregulation of many genes in response to elevated IOP and optic nerve transection. However, the retina is a complex tissue composed of neuronal, glial and vascular cell types. The RGCs only comprise 5% or less of retinal cells. The gene expression profiles from whole retina can not represent of RGC gene expression. In the current study, we sought to investigate the whole genome regulation of the RGCs in glaucoma. The study was carried out in 3 adult male Brown Norway rats with experimental glaucoma. An equal number of RGCs were captured from normal eyes and eyes with elevated IOP. Gene expression in the glaucomatous RGC was compared with that in the fellow RGC by using Affymetrix Gene chip.
Project description:Glaucoma is a common ocular disorder that is a leading cause of blindness worldwide. It is characterized by the dysfunction and loss of retinal ganglion cells (RGCs). Although many studies have implicated various molecules in glaucoma, no mechanism has been shown to be responsible for the earliest detectable damage to RGCs and their axons in the optic nerve. Here, we show that the leukocyte transendothelial migration pathway is activated in the optic nerve head at the earliest stages of disease in an inherited mouse model of glaucoma. This resulted in proinflammatory monocytes entering the optic nerve prior to detectable neuronal damage. A 1-time x-ray treatment prevented monocyte entry and subsequent glaucomatous damage. A single x-ray treatment of an individual eye in young mice provided that eye with long-term protection from glaucoma but had no effect on the contralateral eye. Localized radiation treatment prevented detectable neuronal damage and dysfunction in treated eyes, despite the continued presence of other glaucomatous stresses and signaling pathways. Injection of endothelin-2, a damaging mediator produced by the monocytes, into irradiated eyes, combined with the other glaucomatous stresses, restored neural damage with a topography characteristic of glaucoma. Together, these data support a model of glaucomatous damage involving monocyte entry into the optic nerve. Genome-wide assessment of gene expression changes was performed in DBA/2J-Gpnmb+, DBA/2J mice and irradiated DBA/2J mice at 8.5 and 10.5 months of age.