Project description:EAE mice were injected with LPC 18:1 at the optic nerve when they exhibited a clinical score of 2. Visual function was assessed via pattern electroretinogram and optic nerves were harvested 12 days post optic nerve injection. Three different visual recovery pathways were observed: 1) No-injection control (no recovery in visual function), 2) Low recovery visual function, 3) High recovery visual function and 4) No change in visual function.
Project description:EAE mice were injected with LPC 18:1 and Isobaric C13-His at the optic nerve when they exhibited a clinical score of 2. Visual function was assessed via pattern electroretinogram and optic nerves were harvested 12 days post optic nerve injection. Optic nerves were processed for mass spectrometry to identify the integration of C13-His in newly synthesized proteins.
Project description:We used two groups of C57BL/6J mice, one with optic nerve crush on one eye, and another with no crush as control. Three mice were subjected to optic nerve crush, with sample names 121, 113, 114 and two were used as control with sample names 118 and 119. For the optic nerve crush, a surgical peritomy was made behind and above the eyeball and the eye muscles were gently retracted to expose the optic nerve. Dumont #5 forceps (FST) were used to crush the optic nerve approximately 0.5-1 mm behind the globe without damaging retinal vessels or affecting the blood supply.
Project description:The optic nerve is an important tissue in glaucoma and the unmyelinated nerve head region remains an important site of many early neurodegenerative changes. In humans and mice, astrocytes constitute the major glial cell type in the region, and in glaucoma they become reactive, influencing the optic nerve head (ONH) microenvironment and disease outcome. To determine the response of ONH astrocytes in glaucoma, we studied their transcriptional response to an elevation in intraocular pressure (IOP) induced by the microbead occlusion model. We also assessed the response of astrocytes in the more distal myelinated optic nerve proper (ONP). In this experimental model, astrocytes of the optic nerve exhibited a region-specific and temporally distinct response: ONH astrocytes showed very few early transcriptional changes and ONP astrocytes demonstrated substantially larger changes over the course of the experiment.
Project description:A major risk factor for glaucomatous optic neuropathy is the level of intraocular pressure (IOP), which can lead to retinal ganglion cell axon injury and cell death. The optic nerve has a rostral unmyelinated portion at the optic nerve head followed by a caudal myelinated region. The unmyelinated region is differentially susceptible to IOP-induced damage in rodent models and in human glaucoma. While several studies have analyzed gene expression changes in the mouse optic nerve following optic nerve injury, few were designed to consider the regional gene expression differences that exist between these distinct areas. We performed bulk RNA-sequencing on the retina and on separately micro-dissected unmyelinated and myelinated optic nerve regions from naïve C57BL/6 mice, mice after optic nerve crush, and mice with microbead-induced experimental glaucoma (total = 36). Gene expression patterns in the naïve unmyelinated optic nerve showed significant enrichment of the Wnt, Hippo, PI3K-Akt, and transforming growth factor β pathways, as well as extracellular matrix–receptor and cell membrane signaling pathways, compared to the myelinated optic nerve and retina. Gene expression changes induced by both injuries were more extensive in the myelinated optic nerve than the unmyelinated region, and greater after nerve crush than glaucoma. Changes present three and fourteen days after injury largely subsided by six weeks. Gene markers of reactive astrocytes did not consistently differ between injury states. Overall, the transcriptomic phenotype of the mouse unmyelinated optic nerve was significantly different from immediately adjacent tissues, likely dominated by expression in astrocytes, whose junctional complexes are inherently important in responding to IOP elevation.
Project description:Primary cultures of astrocytes from rat optic nerve heads were treated with EGFR ligand, EGF. Two cell lines from two different rat donors were used. The sister cell cultures were set as control and EGF treated groups. Experiment Overall Design: experiment #1: compared control astrocyte cultures to sister cultures treated with EGF for 4 hours. Experiment Overall Design: experiment #2: compared control astrocyte cultures to sister cultures treated with EGF for 12 hours
Project description:Reactive gliosis is a complex process that involves profound changes in gene expression. We used microarray to indentify differentially expressed genes and to investigate the molecular mechanisms of reactive gliosis in optic nerve head in response to optic nerve crush injury. C57Bl/6 female mice were 6-8 weeks old at the time of optic nerve crush surgery. The optic nerve in the left eye was crush 1 mm behind the globe for 10 seconds and the right eye served as contralateral control. The animals were allowed to recover for 1 day, 3 day, 1 week, 3 weeks and 3 months before the optic nerve heads were collected. The naive control mice did not receive any surgery in either eye. Due to the small tissue size of the mouse optic nerve head, two optic nerve heads were pooled together for each microarray chip. The left eyes and the right eyes of two mice were combined respectively to form one pair of experiment and control samples. There were five biological replicates (10 mice) for each condition.
Project description:Changes in gene expression that occur across the entire central nervous system (CNS) during disease do not take into account variability from one CNS region to another and can be confounded by alterations in cellular composition during disease. Multiple sclerosis (MS) is characterized by cell proliferation, migration and damage in various cell types in different CNS regions and causes disabilities related to distinct neurological pathways, such as walking, vision and cognition. Here, a cell-specific and region-specific transcriptomic approach was used to determine changes in gene expression in astrocytes derived from spinal cord, cerebellum, cerebral cortex, and hippocampus in the preclinical MS model, chronic experimental autoimmune encephalomyelitis (EAE). RNA sequencing and bioinformatics analysis showed that changes in gene expression pathways in astrocytes differed between neuroanatomic regions. Further, while astrocytes from spinal cord showed increased expression of immune pathway genes during EAE, cholesterol biosynthesis pathway genes were decreased. Translating these findings from the preclinical model to humans, optic nerve from EAE and optic chiasm from MS each showed a significant decrease in cholesterol biosynthesis pathways. Finally, a treatment targeting cholesterol homeostasis in astrocytes was protective in EAE, suggesting a novel neuroprotective strategy for MS. Using a cell-specific and region-specific gene expression approach can provide therapeutically relevant insights into mechanisms underlying specific disabilities in complex multifocal neurological diseases.
Project description:Changes in gene expression that occur across the entire central nervous system (CNS) during disease do not take into account variability from one CNS region to another and can be confounded by alterations in cellular composition during disease. Multiple sclerosis (MS) is characterized by cell proliferation, migration and damage in various cell types in different CNS regions and causes disabilities related to distinct neurological pathways, such as walking, vision and cognition. Here, a cell-specific and region-specific transcriptomic approach was used to determine changes in gene expression in astrocytes derived from spinal cord, cerebellum, cerebral cortex, and hippocampus in the preclinical MS model, chronic experimental autoimmune encephalomyelitis (EAE). RNA sequencing and bioinformatics analysis showed that changes in gene expression pathways in astrocytes differed between neuroanatomic regions. Further, while astrocytes from spinal cord showed increased expression of immune pathway genes during EAE, cholesterol biosynthesis pathway genes were decreased. Translating these findings from the preclinical model to humans, optic nerve from EAE and optic chiasm from MS each showed a significant decrease in cholesterol biosynthesis pathways. Finally, a treatment targeting cholesterol homeostasis in astrocytes was protective in EAE, suggesting a novel neuroprotective strategy for MS. Using a cell-specific and region-specific gene expression approach can provide therapeutically relevant insights into mechanisms underlying specific disabilities in complex multifocal neurological diseases.