title: Curcumin suppresses Janus kinase-STAT inflammatory signaling through activation of Src homology 2 domain-containing tyrosine phosphatase 2 in brain microglia.
abstract: Curcumin has been strongly implicated as an anti-inflammatory agent, but the precise mechanisms of its action are largely unknown. In this study, we show that the inhibitory action of curcumin on Janus kinase (JAK)-STAT signaling can contribute to its anti-inflammatory activity in the brain. In both rat primary microglia and murine BV2 microglial cells, curcumin effectively suppressed the ganglioside-, LPS-, or IFN-gamma-stimulated induction of cyclooxygenase-2 and inducible NO synthase, important enzymes that mediate inflammatory processes. These anti-inflammatory effects appear to be due, at least in part, to the suppression of the JAK-STAT inflammatory signaling cascade. Curcumin markedly inhibited the phosphorylation of STAT1 and 3 as well as JAK1 and 2 in microglia activated with gangliosides, LPS, or IFN-gamma. Curcumin consistently suppressed not only NF binding to IFN-gamma-activated sequence/IFN-stimulated regulatory element, but also the expression of inflammation-associated genes, including ICAM-1 and monocyte chemoattractant protein 1, whose promoters contain STAT-binding elements. We further show that activation of Src homology 2 domain-containing protein tyrosine phosphatases (SHP)-2, a negative regulator of JAK activity, is likely to be one of the mechanisms underlying the curcumin-mediated inhibition of JAK-STAT signaling. Treatment of microglial cells with curcumin led to an increase in phosphorylation and association with JAK1/2 of SHP-2, which inhibit the initiation of JAK-STAT inflammatory signaling in activated microglia. Taken together, these data suggest curcumin suppresses JAK-STAT signaling via activation of SHP-2, thus attenuating inflammatory response of brain microglial cells.
authors.affiliation: Department of Pharmacology, Ajou University Medical School, Suwon, Korea.
authors.forename: Hee Young
authors.initials: HY
authors.lastname: Kim
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Park
authors.forename: Eun-Hye
authors.initials: EH
authors.lastname: Joe
authors.forename: Ilo
authors.initials: I
authors.lastname: Jou
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D003474:Curcumin / Q000494:pharmacology*; D051546:Cyclooxygenase 2; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000502:physiology; D015536:Down-Regulation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D007249:Inflammation / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control; D007371:Interferon-gamma / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D017628:Microglia / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II; D010766:Phosphorylation / Q000187:drug effects; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis; D054648:Protein Phosphatase 2; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000502:physiology; D011518:Proto-Oncogene Proteins; D051381:Rats; D017207:Rats, Sprague-Dawley; D012045:Regulatory Sequences, Nucleic Acid; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology; D015534:Trans-Activators / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects; D018909:src Homology Domains / Q000502:physiology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; D011518:Proto-Oncogene Proteins; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor; C494081:Stat1 protein, rat; C494088:Stat3 protein, rat; D015534:Trans-Activators; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D011505:Protein-Tyrosine Kinases; C507906:Jak1 protein, rat; C507927:Jak2 protein, rat; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D054648:Protein Phosphatase 2; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases; C516727:Ptpn11 protein, rat; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D003474:Curcumin