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SOCS3 Expression (socs3 + expression)
Selected AbstractsIFN-,-induced BACE1 expression is mediated by activation of JAK2 and ERK1/2 signaling pathways and direct binding of STAT1 to BACE1 promoter in astrocytesGLIA, Issue 3 2007Hyun Jin Cho Abstract ,-Site APP cleaving enzyme 1 (BACE1) is an essential enzyme for the production of , amyloid. Since we found that injection of interferon-, (IFN-,) into young mouse brains increased BACE1 expression in astrocytes, we investigated molecular mechanisms underlying this process by cloning a putative BACE1 promoter. BACE1 promoter activity was differentially regulated by IFN-, in a region specific manner and down-regulated by an inhibitor of Janus kinase 2 (JAK2). A dominant negative mutant of signal transducer and activator of transcription 1 (STAT1) expression suppressed BACE1 promoter activity, and this was rescued by transfecting wild type STAT1. Electrophoretic mobility shift assay and promoter activity assays indicated that STAT1 binds directly to the putative STAT1 binding sequence of BACE1 promoter. Because IFN-, treatment induced STAT1 phosphorylation, we examined whether the expression of a suppressor of cytokine signaling (SOCS), negative regulator of JAK2, suppresses BACE1 promoter activity. The results show that SOCS1 or SOCS3 expression suppressed BACE1 promoter by blocking phosphorylation of Tyr701 residue in STAT1. Also, because IFN-, treatment specifically potentiated extracellular signal regulated MAP kinase (ERK) 1/2 activation, pretreatment of mitogen-activated or extracellular signal-regulated protein kinase (MEK) inhibitor, PD98059, significantly attenuated IFN-,-induced BACE1 promoter activity and protein expression through blocking phosphorylation of Ser727 residue in STAT1, suggesting that ERK1/2 is associated with IFN-,-induced STAT1 signaling cascade. Taken together, our results suggest that IFN-, activates JAK2 and ERK1/2 and then phosphorylated STAT1 binds to the putative STAT1 binding sequences in BACE1 promoter region to modulate BACE1 protein expression in astrocytes. © 2006 Wiley-Liss, Inc. [source] Involvement of the JAK-STAT pathway and SOCS3 in the regulation of adiponectin-generated reactive oxygen species in murine macrophage RAW 264 cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2010Sumio Akifusa Abstract Adiponectin is a protein hormone produced by differentiating adipocytes and has been proposed to have anti-diabetic and immunosuppressive properties. We previously reported that the globular form of adiponectin (gAd) induces the generation of reactive oxygen species (ROS) and nitric oxide (NO), followed by caspase-dependent apoptotic cell death in RAW 264 cells. Here, we demonstrate that gAd-induced ROS generation and apoptosis were diminished by suppressor of cytokine signaling 3 (SOCS3). The phosphorylation level of signal transducer and activator of transcription (STAT) 3 detected by Western blotting was highest at 20,min in gAd-treated RAW 264 cells. This phosphorylation was inhibited by AG490, a specific inhibitor of janus-activator kinase (JAK). The gAd-induced ROS and NO were reduced by administration of AG490 and Jak-2-specific siRNA in RAW 264 cells. The gAd stimulation transiently induced SOCS3 mRNA expression and protein production. We examined SOCS3-overexpressing RAW 264 cells to investigate the role of the JAK-STAT pathway in gAd-induced ROS and NO generation. SOCS3 overexpression significantly reduced both ROS and NO generation. Additionally, gAd-induced caspase activation and apoptotic cell death were reduced in SOCS3 transfectants compared with vector control transfectants. These results suggest that the JAK-STAT pathway, which can be suppressed by SOCS3 expression, is involved in gAd-induced ROS and NO generation followed by apoptotic cell death. J. Cell. Biochem. 111: 597,606, 2010. © 2010 Wiley-Liss, Inc. [source] Effect of pro-inflammatory and immunoregulatory cytokines on human tenocytesJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 8 2010Thilo John Abstract Tendon injury induces a local inflammatory response, characterized by the induction of pro-inflammatory cytokines. The aim of the present study was to analyze the effects of TNF,, IL-6 and IL-10 on key parameters of tendon homeostasis. Cultured primary human tenocytes were treated with the recombinant cytokines IL-6, IL-10, TNF,, or combinations of TNF, with IL-6 and IL-10 (10 ng/mL, 6, 24 h). Expression of type I collagen, elastin, MMP-1, TNF,, IL-1,, IL-6, IL-10, and suppressors of cytokine signaling (SOCS1, 3) was analyzed with the use of RTD-PCR, immunocytochemistry, and Western blot analysis. In response to TNF,, tenocytes reduced their type I collagen deposition but increased their elastin gene expression and highly upregulated their expression for MMP-1, pro-inflammatory (TNF,, IL-1,) and immunoregulatory (IL-6, IL-10) cytokines. TNF, stimulation augmented SOCS1, whereas SOCS3 expression in tenocytes was also induced by IL-6. The treatment of tenocytes with IL-6 and IL-10 had no effect on cytokine expression. Neither IL-6 nor IL-10 modulated the observed effects of TNF, significantly. These results indicate that TNF, strongly activates the tenocytes to amplify their own TNF, expression and, subsequently, that of other regulatory cytokines and matrix degrading enzymes. However, the impact of IL-6 and IL-10 on tenocytes remains unclear. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1071,1077, 2010 [source] Sequence of administration and methylation of SOCS3 may govern response to gemtuzumab ozogamicin in combination with conventional chemotherapy in patients with refractory or relapsed acute myelogenous leukemia (AML),AMERICAN JOURNAL OF HEMATOLOGY, Issue 7 2010Iris Middeldorf In older patients suffering from acute myelogenous leukemia (AML), aggressive chemotherapy is accompanied with high treatment-related morbidity and mortality. Gemtuzumab ozogamicin (GO), a humanized monoclonal anti-CD33 antibody, represents a well tolerated treatment option, but optimal treatment schedules are still unknown. Additionally, Suppressor of cytokine signaling 3 (SOCS3) inhibits the CD33-induced block on cytokine-induced proliferation. Consequently, a variable response of AML cells to anti-CD33-targeted therapy may be caused by modulation of SOCS3 expression. Twenty-four patients with refractory or relapsed CD33-positive AML received GO as a single agent before or after conventional chemotherapy. The methylation status of the SOCS3 CpG island was assessed by methylation-specific polymerase chain reaction. Response (RR) and overall survival (OS) were significantly higher in 16 patients receiving chemotherapy before GO (RR 81%, OS 14.8 months) compared to three patients who received GO single agent therapy (RR 33%, OS 7.2 months) or 16 with GO before chemotherapy (RR 0% OS 2.2 months, P = 0.01 for RR and P < 0.001 for OS). Methylation of the SOCS3 CpG island was found in 8/24 patients. There was a trend towards a higher RR and longer OS in patients with SOCS3 hypermethylation (RR 86%, OS 25.1 months) compared to unmethylated SOCS3 (RR 56%, OS 10.3 months, P = 0.09). Administration of GO a few days after chemotherapy seems to provide better response and survival compared to administration of GO directly before chemotherapy. The potential role of SOCS3 hypermethylation as a biomarker should be further investigated in patients undergoing GO containing therapies. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source] Association of neuropeptides with Th1/Th2 balance and allergic sensitization in childrenCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2006G. Herberth Summary Background Among neurogenic factors, the neuropeptides have an important regulatory influence on immune system activity and may lead to allergic sensitization. Objective The aim of our study was to investigate the relationship of the neuropeptides vasoactive intestinal peptide (VIP), somatostatin (SOM) and substance P (SP) on modulation of Th1/Th2 balance and allergic sensitization in children. Methods Within the LISAplus (Life style,Immune system,Allergy) study, blood samples of 321 six-year-old children were analysed for concentration of neuropeptides, Th1 and Th2 cytokines, transcription factors for T cell regulation and suppressors of cytokine signalling. In addition, samples were screened for specific IgE against inhalant and food allergens. Results Children with high SOM values showed a Th2 polarization and a reduced expression of FOXP3, the marker for regulatory T cells. High (VIP) levels correlated inversely with the expression of T cell transcription factors (Tbet and SOCS3). In contrast, elevated levels of SP were associated with reduced GATA3 and SOCS3 expression and with increased IFN-, concentrations. Allergic sensitization was more prevalent in children with higher SOM and VIP concentrations but not associated with SP levels. Conclusion Our data reveal an association between neuropeptides and modulatory effects on immune cells in vivo, especially on Th1/Th2 balance with a correlation to allergic sensitization in children. We suggest that elevated SOM and VIP concentrations and the inducing factors should be considered as allergy risk factors. [source] | |||||||||||||