TGF-β(2)- and H(2)O(2)-induced biological changes in optic nerve head astrocytes are reduced by the antioxidant alpha-lipoic acid.
OBJECTIVE
The goal of the present study was to determine whether transforming growth factor-β(2) (TGF-β(2))- and oxidative stress-induced cellular changes in cultured human optic nerve head (ONH) astrocytes could be reduced by pretreatment with the antioxidant α-lipoic acid (LA).


METHODS
Cultured ONH astrocytes were treated with 1.0 ng/ml TGF-β(2) for 24 h or 200 µM hydrogen peroxide (H(2)O(2)) for 1 h. Lipid peroxidation was measured by a decrease in cis-parinaric acid fluorescence. Additionally, cells were pretreated with different concentrations of LA before TGF-β(2) or H(2)O(2) exposure. Expressions of the heat shock protein (Hsp) αB-crystallin and Hsp27, the extracellular matrix (ECM) component fibronectin and the ECM-modulating protein connective tissue growth factor (CTGF) were examined with immunohistochemistry and real-time PCR analysis.


RESULTS
Both TGF-β(2) and H(2)O(2) increased lipid peroxidation. Treatment of astrocytes with TGF-β(2) and H(2)O(2) upregulated the expression of αB-crystallin, Hsp27, fibronectin and CTGF. Pretreatment with different concentrations of LA reduced the TGF-β(2)- and H(2)O(2)-stimulated gene expressions.


CONCLUSIONS
We showed that TGF-β(2)- and H(2)O(2)-stimulated gene expressions could be prevented by pretreatment with the antioxidant LA in cultured human ONH astrocytes. Therefore, it is tempting to speculate that the use of antioxidants could have protective effects in glaucomatous optic neuropathy.
Department of Ophthalmology, Ludwig-Maximilian University, Munich, Germany. alice.yu@med.uni-muenchen.de
Alice L
AL
Yu
Jerome
J
Moriniere
Ulrich
U
Welge-Lussen
D000368:Aged; D000975:Antioxidants / Q000494:pharmacology*; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor / Q000235:genetics / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D005786:Gene Expression Regulation / Q000187:drug effects; D055551:HSP27 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008875:Middle Aged; D018832:Molecular Chaperones; D009898:Optic Disk / Q000166:cytology*; D018384:Oxidative Stress / Q000187:drug effects*; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D008063:Thioctic Acid / Q000494:pharmacology*; D014019:Tissue Donors; D053781:Transforming Growth Factor beta2 / Q000494:pharmacology*; D015854:Up-Regulation; D038203:alpha-Crystallin B Chain / Q000235:genetics / Q000378:metabolism
D000975:Antioxidants; C526317:CCN2 protein, human; D005353:Fibronectins; D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D012333:RNA, Messenger; D053781:Transforming Growth Factor beta2; D038203:alpha-Crystallin B Chain; D055513:Connective Tissue Growth Factor; D008063:Thioctic Acid; D006861:Hydrogen Peroxide