title: Inhibition of GSK-3beta mediates expression of MMP-9 through ERK1/2 activation and translocation of NF-kappaB in rat primary astrocyte.
abstract: Glycogen synthase kinase (GSK)-3beta and extracellular signal-regulated kinase (ERK) regulate several cellular signaling pathways in common, including embryonic development, cell differentiation and apoptosis. In this study, we investigated whether GSK-3beta inhibition is involved in ERK activation, which affects the activation of NF-kappaB and induction of MMP-9 in cultured rat primary astrocytes. Here, we found that GSK-3beta inhibition using GSK-3beta inhibitor TDZD-8 increased the phosphorylation of GSK-3beta at Ser9 site as well as the phosphorylation of ERK1/2 and Akt at Ser473 site. In this condition, GSK-3beta inhibition increased MMP-9 but not MMP-2 activity in a concentration-dependent manner. In RT-PCR analysis, MMP-9 mRNA level was increased by GSK-3beta inhibition in a concentration-dependent manner. MMP-9 promoter reporter activity was similarly increased by GSK-3beta inhibition. Pretreatment of U-0126 (MEK1/2 inhibitor) completely abolished the GSK-3beta inhibition-induced phosphorylation of ERK1/2. U-0126 prevented GSK-3beta inhibition-mediated induction of MMP-9 reporter activity as well as the MMP-9 gene expression. The transcriptional activity of NF-kappaB was significantly increased by GSK-3beta inhibition, which was determined by nuclear translocation of NF-kappaB. Inhibition of ERK1/2 activity by U-0126 also completely blocked the nuclear translocation of NF-kappaB. Transfection of dominant negative plasmid (S9A) of GSK-3beta significantly decreased phosphorylation of ERK, MMP-9 expression and nuclear translocation of NF-kappaB by GSK-3beta inhibition as compared to wild type GSK-3beta. These data suggest that GSK-3beta inhibition mediates ERK1/2 activation followed by NF-kappaB activation, which directly regulates the induction of MMP-9 in rat primary astrocytes.
authors.affiliation: Laboratory of Pharmacology, College of Pharmacy, Seoul National University, Seoul [151-742], Republic of Korea.
authors.forename: Sun Don
authors.initials: SD
authors.lastname: Kim
authors.forename: Sung-Il
authors.initials: SI
authors.lastname: Yang
authors.forename: Hyoung-Chun
authors.initials: HC
authors.lastname: Kim
authors.forename: Chan Young
authors.initials: CY
authors.lastname: Shin
authors.forename: Kwang Ho
authors.initials: KH
authors.lastname: Ko
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000201:enzymology*; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000187:drug effects / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D010766:Phosphorylation; D021381:Protein Transport / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000502:physiology; D013830:Thiadiazoles / Q000494:pharmacology
chemical_list: C494356:4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione; D004791:Enzyme Inhibitors; D016328:NF-kappa B; D012333:RNA, Messenger; D013830:Thiadiazoles; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D038362:Glycogen Synthase Kinase 3; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9