Taurine protection of PC12 cells against endoplasmic reticulum stress induced by oxidative stress.
BACKGROUND
Taurine is a free amino acid present in high concentrations in a variety of organs of mammalians. As an antioxidant, taurine has been found to protect cells against oxidative stress, but the underlying mechanism is still unclear.


METHODS
In this report, we present evidence to support the conclusion that taurine exerts a protective function against endoplasmic reticulum (ER) stress induced by H2O2 in PC 12 cells. Oxidative stress was introduced by exposure of PC 12 cells to 250 uM H2O2 for 4 hours.


RESULTS
It was found that the cell viability of PC 12 cells decreased with an increase of H2O2 concentration ranging from approximately 76% cell viability at 100 uM H2O2 down to 18% at 500 uM H2O2. At 250 uM H2O2, cell viability was restored to 80% by taurine at 25 mM. Furthermore, H2O2 treatment also caused a marked reduction in the expression of Bcl-2 while no significant change of Bax was observed. Treatment with taurine restored the reduced expression of Bcl-2 close to the control level without any obvious effect on Bax. Furthermore, taurine was also found to suppress up-regulation of GRP78, GADD153/CHOP and Bim induced by H2O2, suggesting that taurine may also exert a protective function against oxidative stress by reducing the ER stress.


CONCLUSIONS
In summary, taurine was shown to protect PC12 cells against oxidative stress induced by H2O2. ER stress was induced by oxidative stress and can be suppressed by taurine.
Pan
Chunliu
C
Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA. cpan@fau.edu
Giraldo
Grace S
GS
Prentice
Howard
H
Wu
Jang-Yen
JY
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D000072224:Bcl-2-Like Protein 11; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004721:Endoplasmic Reticulum / Q000187:drug effects*; D006360:Heat-Shock Proteins / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology*; D016716:PC12 Cells / Q000187:drug effects / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D013654:Taurine / Q000494:pharmacology*; D051742:Transcription Factor CHOP / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP
D000975:Antioxidants; D051017:Apoptosis Regulatory Proteins; D000072224:Bcl-2-Like Protein 11; D006360:Heat-Shock Proteins; D006861:Hydrogen Peroxide; D008565:Membrane Proteins; D016877:Oxidants; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D013654:Taurine; D051742:Transcription Factor CHOP; D051028:bcl-2-Associated X Protein; C000606778:Bcl2l11 protein, rat; C497251:Ddit3 protein, rat; C051684:GRP78 protein, rat; D000091342:Endoplasmic Reticulum Chaperone BiP
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