title: Resveratrol down-regulates a glutamate-induced tissue plasminogen activator via Erk and AMPK/mTOR pathways in rat primary cortical neurons.
abstract: Resveratrol (3,5,4'-trihydroxy-trans-stilbene, RSV) is a polyphenolic compound present in a variety of plant species (including grapes) that produces a myriad of biological activities including anti-inflammatory, antioxidant and neuroprotective effects. In this study, we investigate the effects of resveratrol on the basal and glutamate-stimulated expression and activity of a tissue plasminogen activator (tPA) that plays neuromodulatory or neurotoxic roles in many different neurological situations. Under basal conditions, resveratrol decreased the tPA expression and activity without affecting the tPA mRNA level in rat primary cortical neurons. RSV induced AMPK phosphorylation and inhibited mTOR phosphorylation. Inhibition of AMPK phosphorylation using compound C prevented resveratrol-induced down-regulation of tPA activity. This suggested that AMPK/mTOR-dependent translational inhibition contributes to the down-regulation of the tPA. Under glutamate-stimulated conditions of rat primary cortical neurons, tPA activity and expression were increased along with increased tPA mRNA expression but afterward treatment of RSV inhibited the glutamate-induced increase in tPA activity and expression and tPA mRNA expression. Glutamate stimulation induced activation of Akt and MAPK pathways as well as mTOR which were inhibited by RSV. Interestingly, the Erk pathway inhibitor U0126, but neither PI3K-Akt inhibitor LY294002 nor p38 inhibitor SB203580, mimicked the inhibitory action of RSV on glutamate-induced tPA up-regulation. This suggested the essential role of Erk in the transcriptional up-regulation of tPA expression, which is targeted by RSV. Glutamate stimulation induced neuronal cell death as determined by PI staining and MTT assay. However, RSV protected the cultured rat primary cortical neurons from glutamate-induced cell death as paralleled with the changes in tPA expression. These results suggested that RSV can modulate tPA activity under basal and stimulated conditions by both translational and transcriptional mechanisms. The regulation of the tPA by RSV provides additional therapeutic targets on top of the growing number of molecular substrates of RSV's action in the brain.
authors.affiliation: Department of Neuroscience and Institute of Functional Genomics, Department of Pharmacology, School of Medicine, Konkuk University, 1 Hwayang-Dong, Gwangjin-Gu, Seoul 143-701, Korea. chanyshin@kku.ac.krOr.
authors.forename: Kyu Suk
authors.initials: KS
authors.lastname: Cho
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Lee
authors.forename: Kyoung Ja
authors.initials: KJ
authors.lastname: Kwon
authors.forename: Edson Luck T
authors.initials: EL
authors.lastname: Gonzales
authors.forename: Young Bin
authors.initials: YB
authors.lastname: Kim
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Cheong
authors.forename: Geon Ho
authors.initials: GH
authors.lastname: Bahn
authors.forename: Jongmin
authors.initials: J
authors.lastname: Lee
authors.forename: Seol-Heui
authors.initials: SH
authors.lastname: Han
authors.forename: Yun Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Chan Young
authors.initials: CY
authors.lastname: Shin
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000201:enzymology; D015536:Down-Regulation / Q000187:drug effects; D018698:Glutamic Acid / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000235:genetics / Q000378:metabolism*
chemical_list: D013267:Stilbenes; D018698:Glutamic Acid; D058570:TOR Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D010959:Tissue Plasminogen Activator; D000077185:Resveratrol