Intravitreal injection of β-crystallin B2 improves retinal ganglion cell survival in an experimental animal model of glaucoma

Abstract

Purpose of this study was to investigate firstly specific proteomic changes within the retina in the course of an animal glaucoma model and to identify secondly new approaches for neuroprotective, therapeutic options in glaucoma by addressing those specific changes. Intraocular pressure was elevated through cauterization of episcleral veins in adult Sprague Dawley rats. Molecular and morphological changes were surveyed using mass spectrometry, optical coherence tomography as well as immunohistochemical cross section- and flat mount stainings. By quantifying more than 1500 retinal proteins, it was found that the HspB5 protein and numerous beta-crystallins showed a uniform and unique shifting expression pattern as a result of different periods of elevated IOP exposure. Crystallins showed a significant downregulation (p<0.05) after 3 weeks of elevated IOP and an upregulation after 7 weeks. Counteracting those typical changes, an intravitreal injection of β-crystallin B2 at the time of IOP elevation was found to reduce retinal ganglion cell loss (p<0.05), decrease of the retinal nerve fiber layer (p<0.05) and impairment of the optic nerve. Ultimately, proteomic data revealed that β-crystallin B2 might influence calcium-depended cell signaling pathways with severe effect on apoptosis and gene regulation. In this context especially annexin A5, calcium-transporting ATPase 1 and various histone proteins seem to play a major role.

17β-Estradiol Delivered in Eye Drops: Evidence of Impact on Protein Networks and Associated Biological Processes in the Rat Retina through Quantitative Proteomics

“…Moreover, CRYBB2 upregulation during retinal regeneration in vitro and its localization in RGCs and their axons (including growth cones and filopodia) have also been reported [57]. Perhaps the most compelling evidence of the significance of CRYBB2 for retina neuroprotection has been that its intravitreal injection at the time of IOP elevation improves retinal ganglion cell survival in a rat model of glaucoma combined with mass spectrometry-based proteomics experiments [58]. Overall, the latter revealed CRYBB2 s impact on calcium-dependent cell signaling pathways with profound effect on apoptosis and gene regulation, in which annexin A5, Ca 2+ -transporting ATPase 1, and various histone proteins supposedly play a major role.…”

Erhöhter Augeninnendruck für 7 Wochen induziert lokale Gefäßveränderungen im experimentellen Glaukommodell in vivo

“…Vor und nach der Kauterisation der episkleralen Venen wurde der Augeninnendruck auf beiden Augen gemessen. Dazu diente das Handmessgerät TonoLab (icare, Espoo, Finland) [18,19]. Die Tiere wurden zu den Messungen nicht anästhesiert, sondern horizontal in entspannter Kopfhaltung gehalten.…”

Hydrogen Sulfide and β-Synuclein Are Involved and Interlinked in the Aging Glaucomatous Retina

“…Brn3a immunodetection is a powerful tool to assess RGC survival in several mouse and rat injury models, as shown by Nadal-Nicolas et al [44,45]. In brief, retinal tissue was fixed in 4% formalin solution for 30 min (Carl Roth, Karlsruhe, Germany), transferred in 30% sucrose solution, and finally frozen in methylbutane for 10 seconds (Merck, Germany) and then stained subsequently as previously described [46]. Immunofluorescent RGCs were further visualized with a fluorescent microscope (Carl Zeiss, Ltd., Hertfordshire, UK), images were taken with a magnification of 20-fold, 16 images were captured from each quarter of retinal flat-mounts, and great effort was taken to ensure the proportion of central and peripheral retinal images was identical in every individual retinal piece.…”