Abstract
Although the induction of glutathione S-transferase (GST) activity by tert-butylhydroquinone (tBHQ) has been well-documented in several cell culture systems and rodent experiments, the exact mechanism responsible for its inducibility is still not thoroughly understood. To more precisely define the molecular mechanism of GST induction by tBHQ, we examined the one-electron oxidation and glutathione (GSH) reaction potentials of tBHQ as compared to its analogue, 2,5-di-tert-butylhydroquinone (DtBHQ). tBHQ and DtBHQ showed similar one-electron oxidation potentials, including free radical quenching (antioxidant), oxidative conversion of both compounds to a benzoquinone form, and Cu2+-dependent superoxide generation. On the other hand, the reduced GSH level was observed by the addition of tBHQ, but not DtBHQ, suggesting that tBHQ acts as an electrophile while DtBHQ does not. The data were consistent with the observation that tBHQ more potently induced the GSTP1 gene expression in RL34 cells than DtBHQ did. Moreover, we indeed detected the GSH-tBHQ conjugates in the cells exposed to tBHQ using an electrochemical detector - high-performance liquid chromatography technique. Thus, we conclude that an electrophilic quinone oxidation product that reacts with intracellular nucleophiles including protein thiol or GSH plays a major role in the GSTP1 gene expression.
| Original language | English |
|---|---|
| Pages (from-to) | 4300-4309 |
| Number of pages | 10 |
| Journal | Biochemistry |
| Volume | 42 |
| Issue number | 14 |
| DOIs | |
| Publication status | Published - Apr 15 2003 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Pivotal role of electrophilicity in glutathione S-transferase induction by tert-butylhydroquinone. / Nakamura, Yoshimasa; Kumagai, Takeshi; Yoshida, Chiho; Naito, Yuko; Miyamoto, Masaaki; Ohigashi, Hajime; Osawa, Toshihiko; Uchida, Koji.
In: Biochemistry, Vol. 42, No. 14, 15.04.2003, p. 4300-4309.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Pivotal role of electrophilicity in glutathione S-transferase induction by tert-butylhydroquinone
AU - Nakamura, Yoshimasa
AU - Kumagai, Takeshi
AU - Yoshida, Chiho
AU - Naito, Yuko
AU - Miyamoto, Masaaki
AU - Ohigashi, Hajime
AU - Osawa, Toshihiko
AU - Uchida, Koji
PY - 2003/4/15
Y1 - 2003/4/15
N2 - Although the induction of glutathione S-transferase (GST) activity by tert-butylhydroquinone (tBHQ) has been well-documented in several cell culture systems and rodent experiments, the exact mechanism responsible for its inducibility is still not thoroughly understood. To more precisely define the molecular mechanism of GST induction by tBHQ, we examined the one-electron oxidation and glutathione (GSH) reaction potentials of tBHQ as compared to its analogue, 2,5-di-tert-butylhydroquinone (DtBHQ). tBHQ and DtBHQ showed similar one-electron oxidation potentials, including free radical quenching (antioxidant), oxidative conversion of both compounds to a benzoquinone form, and Cu2+-dependent superoxide generation. On the other hand, the reduced GSH level was observed by the addition of tBHQ, but not DtBHQ, suggesting that tBHQ acts as an electrophile while DtBHQ does not. The data were consistent with the observation that tBHQ more potently induced the GSTP1 gene expression in RL34 cells than DtBHQ did. Moreover, we indeed detected the GSH-tBHQ conjugates in the cells exposed to tBHQ using an electrochemical detector - high-performance liquid chromatography technique. Thus, we conclude that an electrophilic quinone oxidation product that reacts with intracellular nucleophiles including protein thiol or GSH plays a major role in the GSTP1 gene expression.
AB - Although the induction of glutathione S-transferase (GST) activity by tert-butylhydroquinone (tBHQ) has been well-documented in several cell culture systems and rodent experiments, the exact mechanism responsible for its inducibility is still not thoroughly understood. To more precisely define the molecular mechanism of GST induction by tBHQ, we examined the one-electron oxidation and glutathione (GSH) reaction potentials of tBHQ as compared to its analogue, 2,5-di-tert-butylhydroquinone (DtBHQ). tBHQ and DtBHQ showed similar one-electron oxidation potentials, including free radical quenching (antioxidant), oxidative conversion of both compounds to a benzoquinone form, and Cu2+-dependent superoxide generation. On the other hand, the reduced GSH level was observed by the addition of tBHQ, but not DtBHQ, suggesting that tBHQ acts as an electrophile while DtBHQ does not. The data were consistent with the observation that tBHQ more potently induced the GSTP1 gene expression in RL34 cells than DtBHQ did. Moreover, we indeed detected the GSH-tBHQ conjugates in the cells exposed to tBHQ using an electrochemical detector - high-performance liquid chromatography technique. Thus, we conclude that an electrophilic quinone oxidation product that reacts with intracellular nucleophiles including protein thiol or GSH plays a major role in the GSTP1 gene expression.
UR - http://www.scopus.com/inward/record.url?scp=0037446506&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037446506&partnerID=8YFLogxK
U2 - 10.1021/bi0340090
DO - 10.1021/bi0340090
M3 - Article
C2 - 12680784
AN - SCOPUS:0037446506
VL - 42
SP - 4300
EP - 4309
JO - Biochemistry
JF - Biochemistry
SN - 0006-2960
IS - 14
ER -