Korean Journal of Clinical Pharmacy (한국임상약학회지)

Korean College Of Clinical Pharmacy (한국임상약학회)
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Effect of Epigallocatechin Gallate on Phosphoinositide 3-kinase/Akt and Glycogen Synthase Kinase-3 Pathway in Oxidative-stressed N18D3 Cells Following $H_2O_2$ Exposure

산화성 손상을 받은 N18D3세포에서 Epigallocatechin gallate가 Phosphoinositide 3-kinase/Akt 및 Glycogen synthase kinase-3경로에 미치는 효과

  • Koh, Seong Ho (Division of Neurotoxicology, Department of General Toxicoloigy, National Institute of Toxicological Research, KFDA, Department of Neurology, College of Medicine, Hanyang University) ;
  • Kwon, Hyug Sung (Division of Neurotoxicology, Department of General Toxicoloigy, National Institute of Toxicological Research, KFDA) ;
  • Oh, Hwa Soon (Division of Neurotoxicology, Department of General Toxicoloigy, National Institute of Toxicological Research, KFDA) ;
  • Oh, Jae Ho (Division of Neurotoxicology, Department of General Toxicoloigy, National Institute of Toxicological Research, KFDA) ;
  • Park, Ynun Joo (Division of Neurotoxicology, Department of General Toxicoloigy, National Institute of Toxicological Research, KFDA) ;
  • Kim, Jun Gyou (Division of Neurotoxicology, Department of General Toxicoloigy, National Institute of Toxicological Research, KFDA) ;
  • Kim, Ki Sok (Division of Neurotoxicology, Department of General Toxicoloigy, National Institute of Toxicological Research) ;
  • Kim, Yang Soon (Division of Neurotoxicology, Department of General Toxicoloigy, National Institute of Toxicological Research) ;
  • Yang, Ki Hwa (Division of Neurotoxicology, Department of General Toxicoloigy, National Institute of Toxicological Research) ;
  • Kim, Seung U. (Department of Neurology, Ajou University School of Medicine) ;
  • Kim, Seung H. (Department of Neurology, College of Medicine, Hanyang University) ;
  • Jung, Hai Kwu (Division of Neurotoxicology, Department of General Toxicoloigy, National Institute of Toxicological Research)
  • 고성호 (식품의약품안전청 국립독성연구원 신경독성과, 한양대학교 의과대학 신경과학교실) ;
  • 권혁성 (식품의약품안전청 국립독성연구원 신경독성과) ;
  • 오화순 (식품의약품안전청 국립독성연구원 신경독성과) ;
  • 오재호 (식품의약품안전청 국립독성연구원 신경독성과) ;
  • 박윤주 (식품의약품안전청 국립독성연구원 신경독성과) ;
  • 김준규 (식품의약품안전청 국립독성연구원 신경독성과) ;
  • 김기석 (식품의약품안전청 국립독성연구원 신경독성과) ;
  • 김용순 (식품의약품안전청 국립독성연구원 신경독성과) ;
  • 양기화 (식품의약품안전청 국립독성연구원 신경독성과) ;
  • 김승업 (아주대학교 의과대학 신경과학교실) ;
  • 김승현 (한양대학교 의과대학 신경과학교실) ;
  • 정해관 (식품의약품안전청 국립독성연구원 신경독성과)
  • Published : 2003.06.01
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Abstract

Neurodegenerative disorders are associated with apoptosis as a causing factor or an inducer. On the other hand, it has been reported that epigallocatechin gallate (EUG), one of antioxidants and flavonoids, and z-VAD-fmk, a nonselective caspase inhibitor, suppress oxidative-radical-stress-induced apoptosis. However, it is not yet known what is the effects of EGCG and z-VAD-fmk on the apoptotic pathway is through phosphoinositide 3-kinase (PI3K), Akt and glycogen synthase kinase-3 (GSK-3) as well as mitochondria, caspase-3 and poly (ADP-ribose) polymerase (PARP). We investigated the effects of EGCG by using $H_2O_2$ treated N18D3 cells, mouse DRG hybrid neurons. Methods: Following 30 min $100\;{\mu}m\;H_2O_2$ exposure, the viability of N18D3 cells (not pretreated vs. EGCG or z-VAD-fmk pretreated) was evaluated by using MTT assay. The effect of EGCG on immunoreactivity (IR) of cytochrome c, caspase-3, PARP, PI3K/Akt and GSK-3 was examined by using Western blot, and was compared with that of z-Y4D-fmk. Results: EGCG or z-VAD-fmk pretreated N18D3 cells showed increased viability. Dose-dependent inhibition of caspase-3 activation accompanied by PARP cleavage were demonstrated by pretreatment of both agents. However, inhibition of cytochrome c release was only detected in EGCG pretreated N18D3 cells. On the pathway through PI3K/Akt and GSK-3, however, the result of Western blot in EGCG pretreated N18D3 cells showed decreased IR of Akt and GSK-3 and increased IR of p85a PI3K, phosphorylated Akt and GSK-3, and contrasted with that in z-VAD-fmk pretreated N18D3 cells showing no changes on each molecule. Conclusion: These data show that EGCG affects apoptotic pathway through upstream signal including PI3K/Akt and GSK-3 pathway as well as downstream signal including cytochrome c and caspase-3 pathway. Therefore, these results suggest that EGCG mediated activation of PI3K/Akt and inhibition GSK-B could be new potential therapeutic strategy for neurodegenerative diseases associated with oxidative injury.

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