Effects of AG490 on lens epithelial cell death induced by H(2)O(2).
OBJECTIVE
To evaluate the influence of H(2)O(2) on lens epithelial cells (LECs) and to determine the effect of the Janus kinase (JAK) inhibitor AG490 and the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor U0126 on LEC death after H(2)O(2) exposure.


METHODS
Human lens epithelial (HLE) B-3 cells were cultured. Cells were treated for 45 min with H2O2 and signal transducers and activators transcription (STAT) 3, JAK2, and ERK1/2 phosphorylation were surveyed by Western blot analysis. After pretreatment with either 40 microM AG490 or 25 microM U0126, LECs were exposed to H(2)O(2). LEC death was evaluated by microscopy and flow cytometry.


RESULTS
H(2)O(2) induced phosphorylation of Tyr-705 STAT3, JAK2, and ERK1/2 in LECs. In cells pretreated with both AG490 and U0126, phosphorylation of Tyr-705 STAT3, JAK2, and ERK1/2 was suppressed. Microscopic findings, however, showed that only AG490 noticeably enhanced cell survival, and flow cytometry showed that cell necrosis decreased to 4.05% after pretreatment with 40 microM AG490.


CONCLUSIONS
AG490 may prevent H(2)O(2)-induced LEC death by blocking an unknown necrosis pathway. Further investigation is required to characterize that pathway.
Kim
Ungsoo Samuel
US
Department of Ophthalmology, Kim's Eye Hospital, Myung-Gok Eye Research Institute, Konyang University College of Medicine, Seoul, Korea.
Nam
Sang-Min
SM
Jung
Sun-Ah
SA
Kim
Sung Joo
SJ
Lee
Joon H
JH
D017304:Annexin A5 / Q000378:metabolism; D015153:Blotting, Western; D002070:Butadienes / Q000494:pharmacology; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors; D005434:Flow Cytometry; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D053612:Janus Kinases / Q000037:antagonists & inhibitors*; D007908:Lens, Crystalline / Q000187:drug effects* / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors; D009570:Nitriles / Q000494:pharmacology; D018384:Oxidative Stress; D010766:Phosphorylation; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000378:metabolism; D020032:Tyrphostins / Q000494:pharmacology*
D017304:Annexin A5; D002070:Butadienes; D004791:Enzyme Inhibitors; D009570:Nitriles; D019253:Proto-Oncogene Proteins c-bcl-2; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D020032:Tyrphostins; C113580:U 0126; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide; D006861:Hydrogen Peroxide; D053612:Janus Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D053148:Caspase 3
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