Evidence of Hypoxic Glial Cells in a Model of Ocular Hypertension.

Title

Evidence of Hypoxic Glial Cells in a Model of Ocular Hypertension.

Creator

Jassim Assraa H; Inman Denise M

Publisher

Investigative ophthalmology & visual science

Date

2019
2019-01

Description

Purpose: Reoxygenation after hypoxia can increase reactive oxygen species and upregulate autophagy. We determined, for the first time, the impact of elevated IOP on hypoxia induction, superoxide accumulation, and autophagy in a bead model of glaucoma. Method: Ocular hypertension was achieved with magnetic bead injection into the anterior chamber. Before mice were killed, they were injected with pimonidazole for hypoxia detection and dihydroethidium (DHE) for superoxide detection. Total retinal ganglion cells (RGCs) and optic nerve (ON) axons were quantified, total glutathione (GSH) was measured, and retinal and ON protein and mRNA were analyzed for hypoxia (Hif-1alpha and Hif-2alpha), autophagy (LC3 and p62), and SOD2. Results: With IOP elevation (P \textless 0.0001), the retina showed significantly (P \textless 0.001) decreased GSH compared with control, and a significant decrease (P \textless 0.01) in RGC density compared with control. Pimonidazole-positive Muller glia, microglia, astrocytes, and RGCs were present in the retinas after 4 weeks of ocular hypertension but absent in both the control and after only 2 weeks of ocular hypertension. The ON showed significant axon degeneration (P \textless 0.0001). The mean intensity of DHE in the ganglion cell layer and ON significantly increased (P \textless 0.0001). The ratio of LC3-II to LC3-I revealed a significant increase (P \textless 0.05) in autophagic activity in hypertensive retinas compared with control. Conclusions: We report a novel observation of hypoxia and a significant decrease in GSH, likely contributing to superoxide accumulation, in the retinas of ocular hypertensive mice. The significant increase in the ratio of

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

1–15

Issue

1

Volume

60

Citation

Jassim Assraa H; Inman Denise M, “Evidence of Hypoxic Glial Cells in a Model of Ocular Hypertension.,” NEOMED Bibliography Database, accessed November 28, 2021, https://neomed.omeka.net/items/show/4768.

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