Purchase this article with an account.
Xiangjun Yang, Gulgun Tezel; Metabolic Responses of Human Induced Pluripotent Stem Cell-Derived Astrocytes To Glaucoma-Related Stress. Invest. Ophthalmol. Vis. Sci. 2020;61(7):1210.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Recent evidence supports altered metabolic balance of glaucomatous astrocytes. For further analysis of the metabolic responses of astrocytes to glaucoma-related stress, this study took advantage of the human induced pluripotent stem cell(iCell)-based platforms in in vitro modeling of astrocytes.
Human iCell-derived astrocytes were incubated in the presence or absence of glaucoma-related stressors, hypoxia or oxidative stress for 48 hours. In addition to analysis of cell survival (by viability assay), inflammatory phenotype (by glial morphology, GFAP labeling, and cytokine/chemokine profiles), and protein expression profile (by immunoblotting and immunocytochemistry using specific antibodies to various molecular components of cell metabolism), specific assays were used to analyze glycolytic activity (extracellular acidification) and cellular glycogen content. To validate in vitro data, retina and optic nerve sections obtained from human donor eyes with or without glaucoma (and experimental mouse glaucoma) were also analyzed by immunohistochemistry.
iCell astrocytes exposed to hypoxia or oxidative stress exhibited a metabolic shift towards increased glycolysis, in addition to >four-fold increase in pro-inflammatory cytokine secretion (including TNF-α and IFN-γ; P<0.001). Alterations in the protein expression profile supported increased glucose uptake (three-fold increased expression of GLUT-1) and glycolytic metabolism (>two-fold increased expression of hexokinase and pyruvate kinase) and decreased mitochondrial oxidative phosphorylation (>two-fold decreased expression of mitochondrial complex I-V). After exposure to glaucoma-related stress, iCell astrocytes also exhibited ~three-fold increase in extracellular acidification and ~four-fold decrease in cellular gltcogen content (p<0.05). Compared to astrocytes in non-glaucomatous tissues, astrocytes in the glaucomatous human (or mouse) retina and optic nerve presented a similar immunolabeling pattern validating these in vitro observations.
Glaucoma-related glycolytic shift in the bioenergetic profile of iCell astrocytes may support increased energy needs of stressed and inflammatory astrocytes. This shift that may possibly decrease the metabolic support of astrocytes to neurons stimulates additional studies to provide pathogenic and therapeutic implications for increased metabolic vulnerability in glaucoma.
This is a 2020 ARVO Annual Meeting abstract.
This PDF is available to Subscribers Only