Project description:Identification of genes regulated by ATH5 in a dose-dependent manner.; Identification of retinal ganglion cells (RGC)-specific genes.
Project description:The neuronal cell death results in neurodegenerative diseases. The extracellular environment plays a critical role in regulating cell viability. In this study, we explore how intercellular communication contributes to the survival of retinal ganglion cells (RGCs) following the optic nerve crush (ONC). By performing single-cell RNA-seq on whole retinal cells, we observed transcriptomic responses in non-RGC retinal cells to the injury, with astrocytes and Müller glia having the most interactions with RGCs. By comparing the RGC subclasses showing distinct resilience cell death, we identified top 47 interactions that are stronger in the high-survival RGCs, likely representing neuroprotective interactions. We performed functional assays on one of the receptors, Mu-opioid receptor (Oprm1). Although Oprm1 is preferentially expressed in intrinsically photosensitive retinal ganglion cells (ipRGCs), its neuroprotective effect could be transferred to multiple RGC subclasses by specific overexpressing Oprm1 in pan-RGCs. Our study provides an atlas of cell-cell interactions in both intact and post-ONC retina and an effective strategy to predict molecular mechanisms in neuroprotection, underlying the principal role played by extracellular environment in supporting neuron survival.
Project description:Our research focus is to study the genetic etiology and molecular mechanisms of glaucoma, a disease characterized by death of the retinal ganglion cell. The QNR/D cells, the only well validated retinal ganglion cell line, are derived from the neuroretina of quail (Coturnix coturnix japonica) embryos at 7 days gestation, and contain RGC (80%) and amacrine cell (20%) populations. With the aim of investigating the effect of candidate gene on glaucoma, the QNR/D cells were transfected in four different conditions. The RNA-Sequencing analysis on these transfected cell lines to identify the related proteins with differential expression profiles.
Project description:Cue-directed axon guidance depends partly on local translation in growth cones. Many mRNA transcripts are known to reside in developing axons yet little is known about their subcellular distribution or, specifically, which transcripts are in growth cones. Laser capture microdissection (LCM) was used to isolate the growth cones of retinal ganglion cell (RGC) axons of two vertebrate species, mouse and Xenopus, coupled with unbiased genome-wide microarray profiling. Localized mRNA from the isolated growth cones of Xenopus laevis and Mus musculus retinal ganglion cells were subjected to microarray analysis
Project description:To investigate the role of aldose reductase (AR) inhibition using Sorbinil on retinal microglia (RMG) activation, retinal ganglion cell (RGC) survival, and axon regeneration after optic nerve trauma. We observed that AR inhibition using Sorbinil attenuates RMG activation and subsequently promotes RGC survival and delays axon degeneration one week after optic nerve crush.
Project description:The retinal ganglion cell (RGC) competence factor ATOH7 is dynamically expressed during retinal histogenesis. ATOH7 transcription is controlled by a promoter-adjacent primary enhancer and a remote shadow enhancer (SE). Deletion of the ATOH7 human SE causes non‑syndromic congenital retinal non-attachment (NCRNA) disease, characterized by optic nerve aplasia and total blindness. We used genome editing to model NCRNA in mice. Deletion of the murine SE reduces Atoh7 mRNA >5-fold, but does not recapitulate optic nerve loss; however, SEdel/KO (knockout) trans heterozygotes have thin optic nerves. By analyzing Atoh7 mRNA and protein levels, RGC development and survival, and chromatin landscape effects, we show how the SE ensures robust Atoh7 transcriptional output. Combining SE deletion, KO and wild-type alleles in a genotypic series, we determined the amount of Atoh7 needed to produce a normal complement of adult RGCs, and the secondary consequences of graded reductions in Atoh7 dosage. Together these data reveal the workings of an evolutionary fail-safe, a duplicate enhancer mechanism hard-wired in the machinery of vertebrate retinal ganglion cell genesis.
Project description:Retinal ganglion cell (RGC) degeneration is a primary characteristic of glaucoma, although non-cell autonomous mechanisms have been implicated in RGC dysfunction. Astrocytes closely associate with RGCs in the nerve fiber layer of the retina and optic nerve, where they can contribute to RGC neurodegeneration. However, the mechanisms by which astrocytes promote neurotoxicity and contribute to glaucoma remain unclear. Here we present data describing disease phenotypes in astrocytes and their ability to modulate RGC health.
