Hypoxia/reoxygenation and TGF-beta increase alpha B-crystallin expression in human optic nerve head astrocytes

Yu, Alice L. and Fuchshofer, Rudolf and Birke, Marco and Priglinger, Siegfried G. and Eibl, Kirsten H. and Kampik, Anselm and Bloemendal, Hans and Welge-Lussen, Ulrich (2007) Hypoxia/reoxygenation and TGF-beta increase alpha B-crystallin expression in human optic nerve head astrocytes. EXPERIMENTAL EYE RESEARCH, 84 (4). pp. 694-706. ISSN 0014-4835, 1096-0007

Full text not available from this repository. (Request a copy)

Abstract

Reactive astrocytes in glaucomatous optic nerve changes are characterized by an increased expression of alpha B-crystallin and transforming growth factor-beta (TGF-beta). In the pathogenesis of glaucomatous optic nerve damage, ischemia/reperfusion injury may play an important role. The goal of the present study was to determine the influence of hypoxia/reoxygenation and TGF-beta on the expression of alpha B-crystallin in cultured human astrocytes of the optic nerve head (ONH). Cultured human astrocytes were incubated under hypoxic conditions (1% O-2 for 4-12 h) with subsequent reoxygenation (12-24 h). Additionally, cells were treated with 1.0 ng/ml TGF-beta 1 and TGF-beta 2 for 12-48 h. Expression of alpha B-crystallin was examined by Northern- and Western-blotting. Levels of TGF-beta 1 and TGF-beta 2 were analyzed by RT-PCR analysis and ELISA. The effect of TGF-beta blocking on the hypoxia/reoxygenation modulated expression of alpha B-crystallin was investigated by simultaneous incubation with neutralizing antibodies against TGF-beta during the reoxygenation phase. Hypoxia/reoxygenation increased the expression of alpha B-crystallin at the mRNA (2.8- to 3.1-fold) and protein level (1.8- to 2.1-fold). Treatment with 1.0 ng/ml TGF-beta 1 and TGF-beta 2 for 12-48 h markedly enhanced alpha B-crystallin mRNA expression approximately three to fourfold. Using Western blot analysis, this increase ranged from 2 to 3 times. Both cytokines showed a twofold increase after 12 and 24 h of reoxygenation at the mRNA and a two- to threefold increase at the protein level. Simultaneous treatment with neutralizing antibodies against both TGF-beta isoforms prevented the hypoxia/reoxygenation-mediated elevation of alpha B-crystallin. The process of hypoxia/reoxygenation is capable of inducing the expression of alpha B-crystallin and TGF-beta in cultured ONH astrocytes. Therefore, optimization of conditions leading to hypoxia/reoxygenation in the ONH of glaucomatous patients may help to lower the incidence of characteristic changes in the optic nerve. (c) 2006 Elsevier Ltd. All rights reserved.

Item Type: Article
Uncontrolled Keywords: GROWTH-FACTOR-BETA; HUMAN LAMINA-CRIBROSA; SHOCK PROTEINS; TRABECULAR MESHWORK; STRESS-PROTEINS; TRANSFORMING GROWTH-FACTOR-BETA-2; OCULAR HYPERTENSION; ALZHEIMERS-DISEASE; ANGLE GLAUCOMA; AQUEOUS-HUMOR; heat shock protein; optic nerve; astrocyte; transforming growth factor-beta; hypoxia; reoxygenation
Subjects: 500 Science > 570 Life sciences
Divisions: Biology, Preclinical Medicine > Institut für Anatomie > Lehrstuhl für Humananatomie und Embryologie > Prof. Dr. Ernst Tamm
Depositing User: Dr. Gernot Deinzer
Date Deposited: 16 Dec 2020 07:49
Last Modified: 16 Dec 2020 07:49
URI: https://pred.uni-regensburg.de/id/eprint/32939

Actions (login required)

View Item View Item