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Abstract #71460 Published in IGR 18-3
Astrocytes in the Optic Nerve Head of Glaucomatous Mice Display a Characteristic Reactive Phenotype
Wang R; Seifert P; Jakobs TCInvestigative Ophthalmology and Visual Science 2017; 58: 924-932
PURPOSE: Optic nerve head astrocytes, a subtype of white-matter astrocytes, become reactive early in the course of glaucoma. It was shown recently that in the DBA/2J mouse model of inherited glaucoma optic nerve astrocytes extend new longitudinal processes into the axon bundles before ganglion cell loss becomes apparent. The present study aims at testing whether this behavior of astrocytes is typical of early glaucomatous damage. METHODS: Mice expressing green fluorescent protein in individual astrocytes were used to evaluate the early response of astrocytes in the glial lamina of the optic nerve head after increasing the IOP using the microbead occlusion method. Tissue sections from the glial lamina were imaged consecutively by confocal and electron microscopy. RESULTS: Confocal and electron microscope images show that astrocytes close to the myelination transition zone in the hypertensive nerve heads extend new processes that follow the longitudinal axis of the optic nerve and invade axon bundles in the nerve head. Ultrastructurally, the longitudinal processes were largely devoid of subcellular organelles except for degenerating mitochondria. CONCLUSIONS: The longitudinal processes are a common feature of glaucomatous optic nerve astrocytes, whereas they are not observed after traumatic nerve injury. Thus, astrocytes appear to fine-tune their responses to the nature and/or timing of the injury to the neurons that they surround.
The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China 2Department of Ophthalmology, Massachusetts Eye and Ear Infirmary/Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts, United States.
Full articleClassification:
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
5.1 Rodent (Part of: 5 Experimental glaucoma; animal models)
3.6 Cellular biology (Part of: 3 Laboratory methods)
3.1 Microscopy (Part of: 3 Laboratory methods)