title: Long-acting genipin derivative protects retinal ganglion cells from oxidative stress models in vitro and in vivo through the Nrf2/antioxidant response element signaling pathway.
abstract: Previously, we reported that genipin, a herbal iridoid, had neuritogenic and neuroprotective actions on PC12 cells. Although nitric oxide (NO)-activated signalings were proposed to be neuritogenic, the neuroprotective action of genipin remains to be elucidated. From the standpoint of NO activation, we tested a possible protective mechanism through the nitrosative Kelch-like ECH-associated protein (Keap1)/NF-E2-related factor 2 (Nrf2)-antioxidant response element pathway in rat retinal ganglion cells (RGC-5 cells) in culture, and in vivo, against hydrogen peroxide and optic nerve injury (ONI), respectively, using a long-acting (1R)-isoPropyloxygenipin (IPRG001). IPRG001 induced NO generation and the expressions of antioxidative enzymes, such as heme oxygenase-1 (HO-1), in RGC-5 cells. The protective action of IPRG001 depended on HO-1 and NO induction. We found that S-nitrosylation of Keap1 by IPRG001 may contribute to translocation of Nrf2 to the nucleus and triggered transcriptional activation of antioxidative enzymes. Furthermore, apoptotic cells were increased and 4-hydroxy-2-nonenal was accumulated in rat retina following ONI. Pre-treatment with IPRG001 almost completely suppressed apoptosis and accumulation of 4-hydroxy-2-nonenal in RGCs following ONI accompanied by HO-1 induction. These data demonstrate for the first time that IPRG001 exerts neuroprotective action in RGCs in vitro and in vivo, through the Nrf2/antioxidant response element pathway by S-nitrosylation against oxidative stress.
authors.affiliation: Department of Molecular Neurobiology, Graduate School of Medicine, Kanazawa University, Kanazawa, Japan. koriyama@med.kanazawa-u.ac.jp
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Koriyama
authors.forename: Kenzo
authors.initials: K
authors.lastname: Chiba
authors.forename: Matsumi
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Suzuki
authors.forename: Ken-ichiro
authors.initials: K
authors.lastname: Muramoto
authors.forename: Satoru
authors.initials: S
authors.lastname: Kato
mesh_terms: D000447:Aldehydes / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D015153:Blotting, Western; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002843:Chromatin / Q000378:metabolism; D004396:Coloring Agents; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D051547:Heme Oxygenase-1 / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D020287:In Situ Nick-End Labeling; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D057889:Iridoid Glycosides; D039823:Iridoids / Q000494:pharmacology*; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis; D018384:Oxidative Stress / Q000187:drug effects*; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020218:Response Elements / Q000502:physiology; D012165:Retinal Ganglion Cells / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D000447:Aldehydes; D000975:Antioxidants; D002843:Chromatin; D004396:Coloring Agents; D015853:Cysteine Proteinase Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D057889:Iridoid Glycosides; D039823:Iridoids; C431364:KEAP1 protein, human; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D034741:RNA, Small Interfering; D013778:Tetrazolium Salts; D013844:Thiazoles; D009569:Nitric Oxide; D012313:RNA; C007834:genipin; D051547:Heme Oxygenase-1; C022616:thiazolyl blue; C027576:4-hydroxy-2-nonenal