Project description:Transcription profiling by array of mouse male retinas to investigate IGF-I-induced chronic gliosis and retinal stress IGF-I exert multiple effects in different retinal cell populations in both physiological and pathological conditions. Transgenic mice overexpressing IGF-I in the retina showed impaired electroretinographic responses at 6-7 months of age that worsen with age. This retinal neuronal dysfunction was correlated with the loss of rod photoreceptors, bipolar, ganglion and amacrines cells. Neuronal alterations were preceded by the overexpression of retinal stress markers, acute phase proteins and gliosis-related genes. IGF-I overexpression leads to chronic gliosis and microgliosis in TgIGF-I retinas, with mild oxidative stress, impaired recycling of glutamate and defective potassium buffering. These impaired supportive functions can contribute to neurodegeneration in TgIGF-I retinas, together with the increased production of pro-inflammatory cytokines, potential mediators of neuronal death.
Project description:Transcription profiling by array of mouse male retinas to investigate IGF-I-induced chronic gliosis and retinal stress IGF-I exert multiple effects in different retinal cell populations in both physiological and pathological conditions. Transgenic mice overexpressing IGF-I in the retina showed impaired electroretinographic responses at 6-7 months of age that worsen with age. This retinal neuronal dysfunction was correlated with the loss of rod photoreceptors, bipolar, ganglion and amacrines cells. Neuronal alterations were preceded by the overexpression of retinal stress markers, acute phase proteins and gliosis-related genes. IGF-I overexpression leads to chronic gliosis and microgliosis in TgIGF-I retinas, with mild oxidative stress, impaired recycling of glutamate and defective potassium buffering. These impaired supportive functions can contribute to neurodegeneration in TgIGF-I retinas, together with the increased production of pro-inflammatory cytokines, potential mediators of neuronal death. 3 transgenic and 3 wild type biological replicates examined.
Project description:A robust set of CNS transcript changes was defined by comparing microarray data that describe the injury response of the rat retina [Vazquez-Chona et al., IOVS 2004; GSE1001], brain [Matzilevich et al., J Neurosci Res 2002; GSE1911], and spinal cord [Di Giovanni et al., Ann Neurol 2003; GDS63]. We determined the CNS injury genes that were expressed in cultured astrocytes from rat cortex [GSM34300] and from human optic nerve head [Yang et al., Physiol Genomics 2004; GDS532].
Project description:We examined the impact of 17β-estradiol (E2) eye drops on the modulation of the proteome pro-file in the male rat retina. With discovery-driven proteomics, we have identified proteins that were regulated by the treatment. These proteins were assembled to several bioinformatics-based networks implicating E2’s beneficial effects on the male rat retina in a broad context of ocular neuroprotection including the maintenance of retinal homeostasis, facilitation of efficient dis-posal of damaged proteins, and mitochondrial respiratory chain biogenesis. We have also shown for the first time that the hormone’s beneficial effects on the male retina can be con-strained to this target site by treatment with the bioprecursor prodrug DHED. A large concen-tration of E2 was produced after DHED eye drops not only in male rat retinae but also in those of rabbits. However, DHED treatment did not increase circulating E2 levels thereby ensuring therapeutic safety in males. Targeted proteomics focusing on selected biomarkers of E2’s target engagement further confirmed the prodrug’s metabolism to E2 in the male retina and indicated that the retinal impact of DHED treatment was identical to that of the direct E2 treatment. Alto-gether, our study shows the potential of topical DHED therapy for an efficacious and safe protec-tion of the male retina without unwanted hormonal side-effects associated with current estrogen therapies.
Project description:Various retinal disorder such as glaucomatous, retinal ischemia reperfusion, and traumatic optic neuropathy, are involved in the pathogenesis of neurodegeneration via glutamate exicitotoxicity. However, the proteomic characteristics and modulation of the neural-microenvironment with NMDA-induced neurodegeneration in retina and optic nerve remain partly understood. We established a protein sketch of NMDA-induced injury by comparing the proteomes of the PBS-operated, NMDA-operated and control groups. We carried out mass spectrometry-based label-free quantitative proteomics to investigate the exicitotoxic neurodegeneration mechanisms and identify key proteins that regulated neural cell death related signaling pathway in retina and optic nerve spatially. Using LC-MS/MS proteomics analysis, in total, we identified 3532 proteins in retina, 2593 proteins in optic nerve. According to Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), the protein changes and energy metabolism in retina and optic nerve tissue were comprehensively evaluated.
Project description:Various retinal disorder such as glaucomatous, retinal ischemia reperfusion, and traumatic optic neuropathy, are involved in the pathogenesis of neurodegeneration via glutamate exicitotoxicity. However, the proteomic characteristics and modulation of the neural-microenvironment with NMDA-induced neurodegeneration in retina and optic nerve remain partly understood. We established a protein sketch of NMDA-induced injury by comparing the proteomes of the PBS-operated, NMDA-operated and control groups. We carried out mass spectrometry-based label-free quantitative proteomics to investigate the exicitotoxic neurodegeneration mechanisms and identify key proteins that regulated neural cell death related signaling pathway in retina and optic nerve spatially. Using LC-MS/MS proteomics analysis, in total, we identified 3532 proteins in retina, 2593 proteins in optic nerve. According to Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), the protein changes and energy metabolism in retina and optic nerve tissue were comprehensively evaluated.
Project description:To study gene expression changes in the rat retina and choroid following transpupillary thermotherapy (TTT) and to identify molecular mechanisms that may enhance treatment of choroidal neovascularization, complicating age-related macular degeneration. Keywords: Expression level alteration in the rat retina and choroid after TTT
Project description:ChIP-seq of H3K4me3 in rat peripheral nerve was used to identify transcription start sites associated with Schwann cell-expressed genes. The analysis was performed in injured and control nerve to identify injury-responsive changes in Schwann cells. H3K4me3 ChIP samples were prepared from rat sciatic nerve at 1 day post-transection using both the distal stump of the injured nerve and the contralateral (sham) nerve.
Project description:The resident astrocytes-retinal ganglion cell lipoxin circuit is impaired during retinal stress that include exocytotoxic- and ocular hypertension-induced neuropathy. Two endogenous lipoxins (Lipoxin A4 and Lipoxin B4) produced by homeostatic astrocytes directly act on RGCs. LXB4 is the most potent lipoxin in the retina and directly increases RGC survival and function in ocular hypertension-induced neuropathy. Homeostatic roles and cellular targets of LXB4 in the retina and optic nerve are a critical gap in knowledge. Single-cell RNA sequencing was used to define cellular targets and signaling of LXB4 in the retina. For modeling neurodegeneration, sustained ocular hypertension was induced by silicone-oil injection in the anterior chamber of mouse eyes. For morphological characterization of microglia populations in the retina and optic nerve, we used MorphOMICs and pseudotime trajectory analysis. Bulk RNA sequencing of optic nerves was performed to characterize pathways and mechanism of action for LXB4. qPCR and immunohistochemistry were used for validation of transcriptomics data. Student’s t-test and one-way ANOVA were used to determine differences between experimental groups. Single Cell transcriptomic identified microglia as a primary target for LXB4 in the healthy retina. LXB4 downregulated genes that drive microglia environmental sensing and reactivity responses. Analysis of microglia function uncovered that ocular hypertension induces distinct, temporally defined and dynamic phenotypes in the retina and, unexpectedly, in the distal myelinated optic nerve. Microglial expression of CD74, a marker of disease-associated microglia (DAM) in the brain, was only induced in a unique population of optic nerve microglia but not the retina. Genetic deletion of lipoxin formation correlated with presence of a CD74 optic nerve microglia population in normotensive eyes optic, while LXB4 treatment during ocular hypertension shifted optic nerve microglia toward a homeostatic morphology and non-reactive state and downregulated expression of CD74. Furthermore, we identified a correlation between CD74 and phospho-PI3K (p-PI3K) expression levels in the optic nerve, that was reduced by LXB4 treatment. Results identify distal optic nerve microglial dynamic and reactive responses as a key feature of ocular hypertension induce neurodegeneration. Our findings establish microglia regulation as a new LXB4 cell target in the retina and optic nerve. LXB4 maintenance of optic nerve microglia homeostatic phenotype and inhibition of a disease-associated phenotype are potential mechanisms for LXB4 neuroprotection.
Project description:The resident astrocytes-retinal ganglion cell lipoxin circuit is impaired during retinal stress that include exocytotoxic- and ocular hypertension-induced neuropathy. Two endogenous lipoxins (Lipoxin A4 and Lipoxin B4) produced by homeostatic astrocytes directly act on RGCs. LXB4 is the most potent lipoxin in the retina and directly increases RGC survival and function in ocular hypertension-induced neuropathy. Homeostatic roles and cellular targets of LXB4 in the retina and optic nerve are a critical gap in knowledge. Single-cell RNA sequencing was used to define cellular targets and signaling of LXB4 in the retina. For modeling neurodegeneration, sustained ocular hypertension was induced by silicone-oil injection in the anterior chamber of mouse eyes. For morphological characterization of microglia populations in the retina and optic nerve, we used MorphOMICs and pseudotime trajectory analysis. Bulk RNA sequencing of optic nerves was performed to characterize pathways and mechanism of action for LXB4. qPCR and immunohistochemistry were used for validation of transcriptomics data. Student’s t-test and one-way ANOVA were used to determine differences between experimental groups. Single Cell transcriptomic identified microglia as a primary target for LXB4 in the healthy retina. LXB4 downregulated genes that drive microglia environmental sensing and reactivity responses. Analysis of microglia function uncovered that ocular hypertension induces distinct, temporally defined and dynamic phenotypes in the retina and, unexpectedly, in the distal myelinated optic nerve. Microglial expression of CD74, a marker of disease-associated microglia (DAM) in the brain, was only induced in a unique population of optic nerve microglia but not the retina. Genetic deletion of lipoxin formation correlated with presence of a CD74 optic nerve microglia population in normotensive eyes optic, while LXB4 treatment during ocular hypertension shifted optic nerve microglia toward a homeostatic morphology and non-reactive state and downregulated expression of CD74. Furthermore, we identified a correlation between CD74 and phospho-PI3K (p-PI3K) expression levels in the optic nerve, that was reduced by LXB4 treatment. Results identify distal optic nerve microglial dynamic and reactive responses as a key feature of ocular hypertension induce neurodegeneration. Our findings establish microglia regulation as a new LXB4 cell target in the retina and optic nerve. LXB4 maintenance of optic nerve microglia homeostatic phenotype and inhibition of a disease-associated phenotype are potential mechanisms for LXB4 neuroprotection.