Evidence of Hypoxic Glial Cells in a Model of Ocular Hypertension

Overview

Journal Invest Ophthalmol Vis Sci

Specialty Ophthalmology

Date 2019 Jan 3

PMID 30601926

Citations 23

Authors

Assraa H Jassim

Denise M Inman

Affiliations

Soon will be listed here.

Abstract

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-1α and Hif-2α), autophagy (LC3 and p62), and SOD2.

Results: With IOP elevation (P < 0.0001), the retina showed significantly (P < 0.001) decreased GSH compared with control, and a significant decrease (P < 0.01) in RGC density compared with control. Pimonidazole-positive Müller 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 < 0.0001). The mean intensity of DHE in the ganglion cell layer and ON significantly increased (P < 0.0001). The ratio of LC3-II to LC3-I revealed a significant increase (P < 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 LC3-II to LC3-I suggests autophagy induction.

Citing Articles

C/EBP Homologous Protein Expression in Retinal Ganglion Cells Induces Neurodegeneration in Mice.

Mayhew W, Kaipa B, Li L, Maddineni P, Sundaresan Y, Clark A Int J Mol Sci. 2025; 26(5).

PMID: 40076484 PMC: 11899906. DOI: 10.3390/ijms26051858.

Recent Insights into Roles of Hypoxia-Inducible Factors in Retinal Diseases.

Lee D, Tomita Y, Miwa Y, Kunimi H, Nakai A, Shoda C Int J Mol Sci. 2024; 25(18).

PMID: 39337623 PMC: 11432567. DOI: 10.3390/ijms251810140.

Mitochondria in Retinal Ganglion Cells: Unraveling the Metabolic Nexus and Oxidative Stress.

Yang T, Kang E, Lin P, Yu B, Wang J, Chen V Int J Mol Sci. 2024; 25(16).

PMID: 39201313 PMC: 11354650. DOI: 10.3390/ijms25168626.

Pigment Dispersion Contributes to Ocular Immune Privilege in a DBA/2J Mouse Model of Pigmentary Glaucoma.

Li Q, Pu L, Cheng S, Tang S, Zhang J, Qing G Invest Ophthalmol Vis Sci. 2024; 65(8):51.

PMID: 39083309 PMC: 11290564. DOI: 10.1167/iovs.65.8.51.

Ocular Inflammation and Oxidative Stress as a Result of Chronic Intermittent Hypoxia: A Rat Model of Sleep Apnea.

Donkor N, Gardner J, Bradshaw J, Cunningham R, Inman D Antioxidants (Basel). 2024; 13(7).

PMID: 39061946 PMC: 11273423. DOI: 10.3390/antiox13070878.

References

Cheng L, Yu H, Yan N, Lai K, Xiang M . Hypoxia-Inducible Factor-1α Target Genes Contribute to Retinal Neuroprotection. Front Cell Neurosci. 2017; 11:20. PMC: 5326762. DOI: 10.3389/fncel.2017.00020. View

Loor G, Kondapalli J, Iwase H, Chandel N, Waypa G, Guzy R . Mitochondrial oxidant stress triggers cell death in simulated ischemia-reperfusion. Biochim Biophys Acta. 2010; 1813(7):1382-94. PMC: 3089816. DOI: 10.1016/j.bbamcr.2010.12.008. View

Pursiheimo J, Rantanen K, Heikkinen P, Johansen T, Jaakkola P . Hypoxia-activated autophagy accelerates degradation of SQSTM1/p62. Oncogene. 2008; 28(3):334-44. DOI: 10.1038/onc.2008.392. View

Shih A, Johnson D, Wong G, Kraft A, Jiang L, Erb H . Coordinate regulation of glutathione biosynthesis and release by Nrf2-expressing glia potently protects neurons from oxidative stress. J Neurosci. 2003; 23(8):3394-406. PMC: 6742304. View

Rantanen K, Pursiheimo J, Hogel H, Miikkulainen P, Sundstrom J, Jaakkola P . p62/SQSTM1 regulates cellular oxygen sensing by attenuating PHD3 activity through aggregate sequestration and enhanced degradation. J Cell Sci. 2013; 126(Pt 5):1144-54. DOI: 10.1242/jcs.115667. View

Chidlow G, Wood J, Casson R . Investigations into Hypoxia and Oxidative Stress at the Optic Nerve Head in a Rat Model of Glaucoma. Front Neurosci. 2017; 11:478. PMC: 5573812. DOI: 10.3389/fnins.2017.00478. View

Yang Q, Cho K, Chen H, Yu D, Wang W, Luo G . Microbead-induced ocular hypertensive mouse model for screening and testing of aqueous production suppressants for glaucoma. Invest Ophthalmol Vis Sci. 2012; 53(7):3733-41. PMC: 3390181. DOI: 10.1167/iovs.12-9814. View

Chen C, Pore N, Behrooz A, Ismail-Beigi F, Maity A . Regulation of glut1 mRNA by hypoxia-inducible factor-1. Interaction between H-ras and hypoxia. J Biol Chem. 2000; 276(12):9519-25. DOI: 10.1074/jbc.M010144200. View

Dengler-Crish C, Smith M, Inman D, Wilson G, Young J, Crish S . Anterograde transport blockade precedes deficits in retrograde transport in the visual projection of the DBA/2J mouse model of glaucoma. Front Neurosci. 2014; 8:290. PMC: 4166356. DOI: 10.3389/fnins.2014.00290. View

10.

Mansfield K, Guzy R, Pan Y, Young R, Cash T, Schumacker P . Mitochondrial dysfunction resulting from loss of cytochrome c impairs cellular oxygen sensing and hypoxic HIF-alpha activation. Cell Metab. 2005; 1(6):393-9. PMC: 3141219. DOI: 10.1016/j.cmet.2005.05.003. View

11.

Hernansanz-Agustin P, Izquierdo-Alvarez A, Sanchez-Gomez F, Ramos E, Villa-Pina T, Lamas S . Acute hypoxia produces a superoxide burst in cells. Free Radic Biol Med. 2014; 71:146-156. DOI: 10.1016/j.freeradbiomed.2014.03.011. View

12.

Guo X, Dason E, Zanon-Moreno V, Jiang Q, Nahirnyj A, Chan D . PGC-1α signaling coordinates susceptibility to metabolic and oxidative injury in the inner retina. Am J Pathol. 2014; 184(4):1017-1029. DOI: 10.1016/j.ajpath.2013.12.012. View

13.

Samsel P, Kisiswa L, Erichsen J, Cross S, Morgan J . A novel method for the induction of experimental glaucoma using magnetic microspheres. Invest Ophthalmol Vis Sci. 2010; 52(3):1671-5. DOI: 10.1167/iovs.09-3921. View

14.

Rodriguez A, Perez de Sevilla Muller L, Brecha N . The RNA binding protein RBPMS is a selective marker of ganglion cells in the mammalian retina. J Comp Neurol. 2013; 522(6):1411-43. PMC: 3959221. DOI: 10.1002/cne.23521. View

15.

Tezel G . Oxidative stress in glaucomatous neurodegeneration: mechanisms and consequences. Prog Retin Eye Res. 2006; 25(5):490-513. PMC: 1820838. DOI: 10.1016/j.preteyeres.2006.07.003. View

16.

Almeida A, Delgado-Esteban M, Bolanos J, Medina J . Oxygen and glucose deprivation induces mitochondrial dysfunction and oxidative stress in neurones but not in astrocytes in primary culture. J Neurochem. 2002; 81(2):207-17. DOI: 10.1046/j.1471-4159.2002.00827.x. View

17.

Tezel G, Wax M . Hypoxia-inducible factor 1alpha in the glaucomatous retina and optic nerve head. Arch Ophthalmol. 2004; 122(9):1348-56. DOI: 10.1001/archopht.122.9.1348. View

18.

Zhang H, Bosch-Marce M, Shimoda L, Tan Y, Baek J, Wesley J . Mitochondrial autophagy is an HIF-1-dependent adaptive metabolic response to hypoxia. J Biol Chem. 2008; 283(16):10892-903. PMC: 2447655. DOI: 10.1074/jbc.M800102200. View

19.

Schroedl C, McClintock D, Budinger G, Chandel N . Hypoxic but not anoxic stabilization of HIF-1alpha requires mitochondrial reactive oxygen species. Am J Physiol Lung Cell Mol Physiol. 2002; 283(5):L922-31. DOI: 10.1152/ajplung.00014.2002. View

20.

Coughlin L, Morrison R, Horner P, Inman D . Mitochondrial morphology differences and mitophagy deficit in murine glaucomatous optic nerve. Invest Ophthalmol Vis Sci. 2015; 56(3):1437-46. PMC: 4347310. DOI: 10.1167/iovs.14-16126. View