Effects of Suppressor of Cytokine Signaling-1 Silencing on the Proliferation and Interferon Gamma Susceptibility of Human Pancreatic Cancer Cells / 天津医药

Objective To detect the changes of cell proliferation and IFN-γsusceptibility of human pancreatic can-cer cells after suppressor of cytokine signaling-1 (SOCS1) gene silencing, and to explore the SOCS1 as the target of anti-tu-mor therapy through enhancing the function of IFN-γ. Methods Western blot assay, PCR and real-time PCR were used to verify the down regulation of SOCS1 in human pancreatic cancer cell (PANC1) after transfection;subsequently, PANC1 was stimulated with IFN-γ. Western blot assay was also used to detect the expression of signal transducers and activators of tran-scription (STAT)1 and phosphorylation STAT(pSTAT)1;and the change of IFN-γsusceptibility was detected by MTT assay. Real-time PCR was used to detect the mRNA of interferon regulatory factor-1(IRF-1). Flow cytometry was used to detect the cell cycle. Results The expression levels of SOCS1 mRNA and protein were significantly decreased in small hairpin SCOS1 (shSOCS1) transfected PANC1 cells. After the silence of SOCS1, the expression levels of IRF-1 and pSTAT1 in-creased significantly (P<0.05), and the median inhibitory concentration(IC50)of IFN-γfor PANC1 cells decreased signifi-cantly (P<0.01). The cell count of shSOCS1 cells dropped significantly compared with that of control group after the SOCS1 silencing for 72 hours (P<0.05). The cell cycle arrest was promoted at the G0/G1 phase, but the percentage of cells in S phase and G2/M decreased compared to that of control groups (P<0.05). Conclusion After the inhibition of SOCS1 gene expression, the proliferation ability of human pancreatic cancer cell line PANC1 decreased, and the sensitivity of PANC1 cells to IFN-γwas enhanced.

Changes of Th1/Th2 balance in multiple organ dysfunction syndrome / 第二军医大学学报

Objective: To explore the pathogenesis of multiple organ dysfunction syndrome (MODS) with respect to the balance of Th1/Th2. Methods: Eighteen healthy male minipigs, weighing 22-30 kg, were randomly divided into two groups: MODS group and control group. Double-hit method including hemorrhagic shock and endotoxiemia was used to establish the porcine MODS model. The peripheral vein blood samples were collected at different time-points (before bloodletting, before endotoxin injection, 1 h, 24 h,48 h and 72 h after endotoxin injection) in the two groups. The spleen samples were collected after death of the animals. Plasma levels of IFN-γ and IL-4 were detected by enzyme-linked immunosorbent assay (ELISA). Real-time PCR was used to detect the expression of IFN-γ, IL-4, T-bet and GATA-3 mRNA (The latter 2 were the key transcription factors associated with Th1/Th2 response) in the spleen samples. Results: The plasma levels of IFN-γ and IL-4 quickly reached the peak values 1 h after the endotoxin injection, then the level of IFN-γ decreased quickly. The ratio of IFN-γ/IL-4 was significantly lower than the baseline value 72 h after endotoxin injection(P = 0.000). The ratio of IFN-γ/IL-4 mRNA in MODS group was obviously lower than that in the control group (P = 0.020); the ratio of T-bet/GATA-3 was also lower in MODS group (P = 0.038). Conclusion: The shift from Th1 to Th2 occurs in the progress of MODS.

Soluble factor from tumor cells induces heme oxygenase-1 by a nitric oxide-independent mechanism in murine peritoneal macrophages

Tumor target-derived soluble secretary factor has been known to influence macrophage activation to induce nitric oxide (NO) production. Since heme oxigenase-1 (HO-1) is induced by a variety of conditions associated with oxidative stress, we questioned whether soluble factor from tumor cells induces HO-1 through NO-dependent mechanism in macrophages. We designated this factor as a tumor-derived macrophage-activating factor (TMAF), because of its ability to activate macrophages to induce iNOS. Although TMAF alone showed modest activity, TMAF in combination with IFN-gamma significantly induced iNOS expression and NO synthesis. Simultaneously, TMAF induced HO-1 and this induction was slightly augmented by IFN-gamma. Surprisingly, however, induction of HO-1 by TMAF was not inhibited by the treatment with the highly selective iNOS inhibitor, 1400 W, indicating that TMAF induces the HO-1 enzyme by a NO-independent mechanism. While rIFN-gamma alone induced iNOS, it had no effect on HO-1 induction by itself. Collectively, the current study reveals that soluble factor from tumor target cells induces HO-1 enzyme in macrophages. However, overall biological significance of this phenomenon remains to be determined.

Induction of nitric oxid esynthase(NOS) by soluble glucocorticoid induced tumor necrosis factor receptor(sGITR) is modulated by IFN-g in murine macrophage

Earlier study showed that glucocorticoid induced tumor necrosis factor receptor (GITR), a new TNFR family, activated murine macrophages to express inducible nitric oxide synthase (iNOS) and to generate nitric oxide (NO). A possible involvement of pro-inflammatory cytokines on NO production by GITR was investigated in vitro systems and signaling molecules contributing to sGITR-induced iNOS production are determined in Raw 264.7 cells, a murine macrophage cell line. The result showed that the synergy was afforded by the combination of GITR with IFN-gamma in a dose-dependent manner but IFN-gamma alone was not able to induce NOS. No effects were observed with TNF-alpha, IL-1beta, or IL-6 co-treated with GITR. To determine signaling molecules contributing to sGITR-induced iNOS production, a specific inhibitor for signal pathway proteins tested showed that PDTC (NF- kB) and genistein (tyrosine kinase) inhibited NOS induction significantly, while sodium orthovanadate (tyrosine phosphatase) potentiated NOS expression. These results suggest that activations of NF-kB were involved in induction of iNOS by GITR and IFN-gamma priming caused earlier and stronger NF-kB activation.

Statin inhibits interferon-gamma-induced expression of intercellular adhesion molecule-1 (ICAM-1) in vascular endothelial and smooth muscle cells

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, known as statins, are widely used for primary and secondary prevention of coronary artery atherosclerosis. Pathogenesis of atherosclerosis is multistep processes where transendothelial migration of various leukocytes including monocytes is a crucial step. Interferon-gamma(IFN-gamma) contributes in this process by activating macrophages and T-lymphocytes, and by inducing adhesion molecules in vascular endothelial and smooth muscle cells. In this study we investigated the expression of intercellular cell adhesion molecule- 1 (ICAM-1) in transformed endothelial cell line ECV304 cells as influenced by lovastatin, tumor necrosis factor-alpha (TNF-alpha) and IFN-gamma. Results show that lovastatin suppresses expression of ICAM-1 by inhibiting the IFN-gamma-induced extracellular signal-regulated kinase (ERK) p44/p42-STAT1 signaling pathway. In cells treated with lovastatin and IFN-gamma.ICAM-1 was expressed at a lower level than in cells treated with IFN-gamma alone. However, lovastatin does not reduce TNF-alpha induced expression of ICAM-1. A similar result was observed in cells treated with the MEKK inhibitor PD98059 and IFN-gamma. Cis-acting DNA sequence elements were identified in the 5'-flanking region of the ICAM-1 promoter that mediate inhibition by lovastatin; these sequences map to the IFN-gamma activated site which also binds the STAT1 homodimer. However, lovastatin did not inhibit IFN-gamma-mediated induction of the Y701 phosphorylated form of STAT1. But lovastatin does inhibit the IFN-gamma-mediated phosphorylation of ERK1/ERK2 (T202/Y204) and S727 phosphorylation of STAT1. TNF-alpha does not induce phosphorylation of ERK1/ERK2 and S727 in ECV304 and smooth muscle cells. The results provide the evidences that statins may have beneficial effects by inhibiting IFN-gamma action in atherosclerotic process

Effects of tumor necrosis factor-? and interferon-? on proliferation of oral submucous fibrosis-derived fibroblasts / 实用口腔医学杂志

Objection: To investigate the effects of tumor necrosis factor-?(TNF-?)and interferon-?(IFN-?) on the proliferation of fibrobl asts from healthy persons(NM-FB) and patients with oral submucous fibrosis(OSF -FB).Methods: Fibroblast cultures were established from t he buccal mucosa of five healthy individuals and six patients with OSF. The effe cts of TNF-? and IFN-? on the proliferation of NM-FB and OSF-FB were studi ed by MTT colorimetric assay.Results: TNF-? at 100～10 0 00 U/ml stimulated NM-FB and OSF-FB proliferation (P

Role of IL-17A and Th17 in inflammatory bowl disease / 中国现代普通外科进展

Objective:To detect the expression of IL-17A、IL-10 and IFN-? in patients wth different forms of inflammatory bowel disease(IBD) during clinical remission phase and investigate their role in the onset and treatment of IBD.Methods:Tissue samples were obtained from patients with ulcerative colitis(UC,n=46),Crohn's disease(CD,n=12),and normal colorectal tissues(n=20).IL-17A expression was evaluated by a standard immunohistochemical procedure.Serum IL-17A、 IL-10 and IFN-? levels were determined by ELISA.Results:IL-17A expression was not detected in samples from normal colonic mucosa but was present in the mucosa of IBD.The level of IL-17A significantly increased in IBD patients while it was not detected in the sera of normal individuals.The level of IL-10 in patients with Crohn's disease was significantly higher than that in patients with ulcerative colitis and control group(P

Regulations of Human Tumor Necrosis Factor and Recombinant Human Interferon-? on activity of Human Polymorphonuclear Neutrophils against Candida albicans / 中华皮肤科杂志

This paper studies tile regulation of cytokines such as human tumor necrosis(Hu-TNF) and recombinant human interferon - (rHu -IFN - ) on activity of human polymorphonuclear neutrophils (PMN) against Candida albicans by determing numbers of colony - forming unit of Candida albicans. We detected that Hu - TNF and rHu IFN st did not interfere directly with fungal growth. These two cytokines enhanced PMN to inhibit Candida albicans growth. When preincubating PMN with Hu --TNF and rHu-IFN -togather, the activity of PMN against Candidaalbicans was synergically enhanced. The degree of enhancement of the activity of PMN againstCandida albicans was highly dependent on these two cytokines - PMN preincubation time. Thus,Hu -- TNF and rHu -- IFN -- have the ability to activate PMN, and the synergistic action of thetwo cytokines may prove clinically effective for increasing the ability of immuncompromised hosts against opportunistic fungal infectons.