PMID- 21194439 OWN - NLM STAT- MEDLINE DCOM- 20110412 LR - 20231213 IS - 1742-2094 (Electronic) IS - 1742-2094 (Linking) VI - 7 DP - 2010 Dec 31 TI - Glycogen synthase kinase-3beta inactivation inhibits tumor necrosis factor-alpha production in microglia by modulating nuclear factor kappaB and MLK3/JNK signaling cascades. PG - 99 LID - 10.1186/1742-2094-7-99 [doi] AB - BACKGROUND: Deciphering the mechanisms that modulate the inflammatory response induced by microglial activation not only improves our insight into neuroinflammation but also provides avenues for designing novel therapies that could halt inflammation-induced neuronal degeneration. Decreasing glycogen synthase kinase-3beta (GSK-3beta) activity has therapeutic benefits in inflammatory diseases. However, the exact molecular mechanisms underlying GSK-3beta inactivation-mediated suppression of the inflammatory response induced by microglial activation have not been completely clarified. Tumor necrosis factor-alpha (TNF-alpha) plays a central role in injury caused by neuroinflammation. We investigated the regulatory effect of GSK-3beta on TNF-alpha production by microglia to discern the molecular mechanisms of this modulation. METHODS: Lipopolysaccharide (LPS) was used to induce an inflammatory response in cultured primary microglia or murine BV-2 microglial cells. Release of TNF-alpha was measured by ELISA. Signaling molecules were analyzed by western blotting, and activation of NF-kappaB and AP-1 was measured by ELISA-based DNA binding analysis and luciferase reporter assay. Protein interaction was examined by coimmunoprecipitation. RESULTS: Inhibition of GSK-3beta by selective GSK-3beta inhibitors or by RNA interference attenuated LPS-induced TNF-alpha production in cultured microglia. Exploration of the mechanisms by which GSK-3beta positively regulates inflammatory response showed that LPS-induced IkappaB-alpha degradation, NF-kappaBp65 nuclear translocation, and p65 DNA binding activity were not affected by inhibition of GSK-3beta activity. However, GSK-3beta inactivation inhibited transactivation activity of p65 by deacetylating p65 at lysine 310. Furthermore, we also demonstrated a functional interaction between mixed lineage kinase 3 (MLK3) and GSK-3beta during LPS-induced TNF-alpha production in microglia. The phosphorylated levels of MLK3, MKK4, and JNK were increased upon LPS treatment. Decreasing GSK-3beta activity blocked MLK3 signaling cascades through disruption of MLK3 dimerization-induced autophosphorylation, ultimately leading to a decrease in TNF-alpha secretion. CONCLUSION: These results suggest that inactivation of GSK-3beta might represent a potential strategy to downregulate microglia-mediated inflammatory processes. FAU - Wang, Mei-Jen AU - Wang MJ AD - Department of Medical Research, Neuro-Medical Scientific Center, Buddhist Tzu Chi General Hospital, Hualien, Taiwan. mjwang@tzuchi.com.tw FAU - Huang, Hsin-Yi AU - Huang HY FAU - Chen, Wu-Fu AU - Chen WF FAU - Chang, Hui-Fen AU - Chang HF FAU - Kuo, Jon-Son AU - Kuo JS LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20101231 PL - England TA - J Neuroinflammation JT - Journal of neuroinflammation JID - 101222974 RN - 0 (Enzyme Inhibitors) RN - 0 (I-kappa B Proteins) RN - 0 (Lipopolysaccharides) RN - 0 (NF-kappa B) RN - 0 (Nfkbia protein, mouse) RN - 0 (Nfkbia protein, rat) RN - 0 (Tumor Necrosis Factor-alpha) RN - 139874-52-5 (NF-KappaB Inhibitor alpha) RN - EC 2.7.11.1 (Glycogen Synthase Kinase 3 beta) RN - EC 2.7.11.1 (Gsk3b protein, mouse) RN - EC 2.7.11.1 (Gsk3b protein, rat) RN - EC 2.7.11.24 (JNK Mitogen-Activated Protein Kinases) RN - EC 2.7.11.25 (MAP Kinase Kinase Kinases) RN - EC 2.7.11.26 (Glycogen Synthase Kinase 3) SB - IM MH - Animals MH - Cell Line MH - Enzyme Inhibitors/metabolism MH - Glycogen Synthase Kinase 3/*antagonists & inhibitors/metabolism MH - Glycogen Synthase Kinase 3 beta MH - I-kappa B Proteins/metabolism MH - Inflammation/chemically induced/immunology MH - JNK Mitogen-Activated Protein Kinases/*metabolism MH - Lipopolysaccharides/pharmacology MH - MAP Kinase Kinase Kinases/*metabolism MH - Mice MH - Microglia/cytology/drug effects/*immunology MH - NF-KappaB Inhibitor alpha MH - NF-kappa B/antagonists & inhibitors/*metabolism MH - RNA Interference MH - Rats MH - Rats, Sprague-Dawley MH - Signal Transduction/*physiology MH - Tumor Necrosis Factor-alpha/*metabolism MH - Mitogen-Activated Protein Kinase Kinase Kinase 11 PMC - PMC3022821 EDAT- 2011/01/05 06:00 MHDA- 2011/04/13 06:00 PMCR- 2010/12/31 CRDT- 2011/01/04 06:00 PHST- 2010/09/20 00:00 [received] PHST- 2010/12/31 00:00 [accepted] PHST- 2011/01/04 06:00 [entrez] PHST- 2011/01/05 06:00 [pubmed] PHST- 2011/04/13 06:00 [medline] PHST- 2010/12/31 00:00 [pmc-release] AID - 1742-2094-7-99 [pii] AID - 10.1186/1742-2094-7-99 [doi] PST - epublish SO - J Neuroinflammation. 2010 Dec 31;7:99. doi: 10.1186/1742-2094-7-99.