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:Glaucoma, a major cause of irreversible blindness, is characterized by optic nerve damage and loss of retinal ganglion cells (RGC). SNPs in the GDP-MANNOSE 4,6-DEHYDRATASE (GMDS) gene have been linked to primary open-angle glaucoma (POAG) and treatment responses. The GMDS gene plays a critical role in fucosylation, a process essential for modifying glycoproteins and glycolipids, yet no mechanism for its role in glaucoma pathology has been described. Our study investigates the effects of gmds haploinsufficiency using a CRISPR/Cas9 induced mutation in zebrafish. RNA sequencing (RNAseq) analysis shows significant downregulation of stress response genes including those of the crystallin family, and increased expression of cell death genes in gmds heterozygous mutant eyes. These gene expression changes correlate with phenotypic alterations, including RGC layer thinning, RGC loss, and reduced optic nerve head width in adult gmds heterozygotes relative to wild type siblings. Our findings provide new insights into the role of GMDS in regulating eye function and suggests that GMDS may influence glaucoma risk by regulating the response to stress. This study provides a layer of functional evidence supporting the predictions made by previous GWAS findings, enhancing our understanding of the genetic basis of glaucoma. It highlights the potential of GMDS as a therapeutic target for mitigating glaucoma-related vision loss, opening new avenues for glaucoma research and treatment development.
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.