Animal Model

     

    Prof. Dr. Dr. Franz Grus

    PD Dr. V. Prokosch-Willing

    Aiwei Liu, M. Sc.

    Hanhan Liu, M. Sc.

    Henrik Tonner, M. Sc.

     

    The Experimental Ophthalmology unit conducts several projects involving glaucoma models.

    Methods:

    • Histology of different tissues (e.g. retina, optic nerve, brain) using light and florescence microscopy
    • Ophthalmologic Examinations (e.g. IOP measurement, fundus examination
    • Proteomics using Maldi-TOF
    • Immunoproteomics using Western blotting (1D and 2D) und antigen microarrays

    Experimental Autoimmune Glaucoma Model

    During the last years an autoimmune involvement has been discussed in the pathogenesis of glaucoma. In several studies we could show significant differences in antibody profiles of glaucoma patients in comparison to healthy subjects. These antibody patterns provide hints for changes in the autoimmunity in glaucoma patients, but this does not necessarily mean that glaucoma is an autoimmune disease.
    Are these antibodies an epiphenomenon or are some of them causative at least in a subset of glaucoma patients?
    In order to test the hypothesis that autoimmunity can be involved in the pathogenesis of glaucoma, we are developed an animal model of Experimental Autoimmune Glaucoma (EAG).
    Similar to the procedures used in autoimmune uveitis (EAU) or experimental autoimmune encephalitis (EAE), we immunize the animals with possible antigens (previously identified in glaucoma patients) and then investigate possible subsequent ganglion cell loss and antibody binding (Fig. 1).
    Figure 1: Experimental Autoimmune Glaucoma Model.
    The goal of this project is to find out how antibodies are involved in the apoptosis of retinal ganglion cells. Other factors, like involvement of glia cells and T-cells, are also examined.
    Figure 2 shows some results from a recent study, where animals where immunized with heat shock protein 27 and showed ganglion cell loss 5 and 6 weeks later.
    Figure 2: A. Intraocular pressure variation in groups 3 and 4: animals immunized with heat shock protein 27 (=columns) and control animals (=zero line). IOP was measured before immunization (baseline) and two and four weeks after immunization. B. Fundus pictures of the left eye of one animal from group 3. The picture on the left was taken as a baseline, the middle one two weeks after immunization, and the right one four weeks after immunization.
    C. Quantification of RGC density (±SE) in all four groups: the control group and animals immunized with HSP27 after 4, 5, and 6 weeks. The difference between the mean cell counts of control and HSP27-immunized groups was significant 5 and 6 weeks after immunization (P=0.05).
    Optic Nerve Crush Model
     
    We are analyzing the immunological modifications of the complex antibody profiles in the nerve crush animal model. Histological analyses of the retina and optic nerve will be performed to find out if retinal ganglion cell loss occurs in these animals.
    Studies suggest that beneficial T cell-dependent immunity is a physiological response to CNS trauma partially counteracting the trauma-induced damage during nerve crush. But there is no knowledge about the modifications of the antibody profiles after optic nerve crush.
    Because of the small blood and aqueous humor sample volumes in animals we developed a method to detect antibody-antigen-reactivities through Protein G beads and ProteinChip technology.
     
    Ischemia Reperfusion Model
    Immunological modifications of the complex antibody profiles in a ischemia reperfusion model are also currently examined. And compared to findings in the Experimental Autoimmune Glaucoma Model.
     
    Effect of muscarinic receptor subtypes on the cholinergic responsiveness of ocular vessels
     
    Acetylcholine regulates perfusion of numerous organs via changes in local blood flow involving muscarinic receptor-induced release of nitric oxide. Five muscarinic acetylcholine receptor subtypes, denoted M1 through M5, have been identified. In ocular arteries, expression and functional relevance of muscarinic receptors remains unknown at present. The purpose of our research project is to determine the expression pattern of muscarinic receptor subtypes in retinal and ciliar arteries in humans and mice. Another major focus of our project is to investigate the impact of muscarinic receptors on vascular responses using in vitro ocular vascular preparations.
    These projects are supported in part by Boehringer Ingelheim Stiftung, Grimmke Stiftung, MAIFOR (Universitätsmedizin), Gertrud Kusen-Stiftung, and others.
     

    Most recent publications:

    Gramlich OW, Beck S, von Thun Und Hohenstein-Blaul N, Boehm N, Ziegler A, Vetter JM, Pfeiffer N, Grus FH (2013) Enhanced insight into the autoimmune component of glaucoma: IgG autoantibody accumulation and pro-inflammatory conditions in human glaucomatous retina. PLoS One 8:e57557.
     
    Gramlich O, Beck S, Ziegler A, Pfeiffer N, Grus F (2013) Autoimmune component in glaucoma: IgG autoantibody accumulation, plasma cells and microglia under pro-inflammatory conditions. Invest Ophthalmol Vis Sci 54:3176-.
     
    Teister J, Gramlich O, Lueckner T, Kriechbaum M, Pfeiffer N, Grus F (2013) Investigation of the retinal thickness using Spectralis OCT(R) reveals a significant decrease after short time elevation of IOP. Invest Ophthalmol Vis Sci 54:1458-.
     
    Lueckner T, Gramlich O, Kriechbaum M, Teister J, Pfeiffer N, Grus F (2013) Suction-cup oculopression offers minimal-invasive opportunities of arbitrary IOP elevations in rats. Invest Ophthalmol Vis Sci 54:1985-.
     
    Gericke A, Goloborodko E, Sniatecki JJ, Steege A, Wojnowski L, Pfeiffer N (2013) Contribution of nitric oxide synthase isoforms to cholinergic vasodilation in murine retinal arterioles. Exp Eye Res 109:60-66.
     
    Gramlich OW, von Pein HD, Ziegler A, Bitz K, Pfeiffer N, Grus FH (2012) Topical Treatment With A Selective COX-2 Inhibitor Promotes Retinal Ganglion Cell Survival After Optic Nerve Crush. Invest Ophthalmol Vis Sci 53:6273-.
     
    Gramlich OW, Joachim SC, Gottschling PF, Laspas P, Cuny CS, Pfeiffer N, Grus FH (2011) Ophthalmopathology in rats with MBP-induced experimental autoimmune encephalomyelitis. Graefes Arch Clin Exp Ophthalmol.
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