Project description:We investigate the therapeutic effect of mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs), a potent immune-modulating therapy for tissue regeneration, in repairing optic nerve damage. Intraocular administration of MSC-sEVs promotes both RGC survival and axon regeneration against optic nerve crush injury. Mechanistically, MSC-sEVs recruits a neural restorative population of hematogenous Ly6Clow monocyte/monocyte-derived macrophage (Mo/MΦ). Gain-of-function by intravitreal administration of the donor Ly6Clow Mo/MΦ markedly improves neurological outcomes in vivo. We then performed gene expression profiling analysis using data obtained from RNA-seq of 4 different cells at two time points.
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:The O-linked β-N-acetylglucosamine (O-GlcNAc) modification on intracellular proteins controls diverse biological processes. Though sustained hyper-O-GlcNAcylation aggravates pathogenesis of many chronic diseases, accumulating evidence also indicates that acute augmentation in O-GlcNAcylation seems to benefit disease healing in some cases. Glucosamine (GlcN) is a freely available and commonly used dietary supplement for human cartilage health, which also activates the hexosamine biosynthesis pathway and induces protein O-GlcNAcylation. Here we show that both GlcN early and late therapies effectively facilitate cardiac recovery in mice by elevating accumulation of Ly6Clow Mo/Mps in infarcted hearts. Eliminating Mo/Mps with clodronate liposomes fully abolishes aforementioned cardiac healing role of GlcN. Importantly, GlcN supplementation accelerates not only in vitro mobility of reparative Mo/Mps but also in vivo infiltration of Ly6Clow Mos. Mechanistically, GlcN positively regulates transcription of myeloid CX3C chemokine receptor 1 (Cx3cr1) by improving STAT1 O-GlcNAcylation, which stabilizes STAT1 and subsequently promotes chemotaxis and infiltration of Ly6Clow Mos. In summary, we identify a novel anti-inflammatory role of GlcN and suggest that its protective effects are mediated through chemotaxis of Ly6Clow Mos in a STAT1/CX3CR1-dependent fashion, which is controlled by O-GlcNAcylation of STAT1. Our study provides a novel clue for Mo/Mps modulator therapies aimed at reducing post-MI hyperinflammation in ischemic myocardium.
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: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.
Project description:The optic nerve is a white matter tract that conveys visual information to the brain. A detailed investigation of the proteome of the normal human retrobulbar optic nerve may help facilitate studies of the biology and pathophysiology of the optic nerve. We conducted an in-depth proteomic analysis of optic nerve from five adults. Proteins were fractionated using SDS-PAGE. After in-gel digestion, peptides were analyzed using LC-MS/MS on an Orbitrap Elite mass spectrometer. We identified 2,711 non-redundant proteins in the human retrobulbar optic nerve, including the astrocytic marker glial fibrillary acidic protein, several proteins expressed by oligodendrocytes (laminin, proteolipid protein, and fibronectin), myelin proteins (myelin basic protein, myelin-associated glycoprotein), paranodal structural proteins (neurofascin, contactin, α, β, and γ adducins, septin 2, endophilin, ankyrin β, spectrin), proteins involved in neuronal protection and regeneration (α crytallins A and B, dedicator of cytokinesis proteins, ciliary neurotrophic factor), proteins associated with open-angle glaucoma (thioredoxin, heat shock protein-70), and proteins associated with optic neuritis (aquaporin-4). Twenty-one unambiguous protein isoforms were identified in the optic nerve.
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:Transcriptomic changes in the pre-chiasmatic optic nerve, retrobulbar optic nerve and retina of goats 1 day after optic nerve crush injury