Norepinephrine inhibits the cytotoxicity of NK92­MI cells via the ß2­adrenoceptor/cAMP/PKA/p­CREB signaling pathway.

Norepinephrine (NE) can regulate natural killer (NK) cell activity, but the mechanism remains unclear. In the present study the roles of adrenergic receptors (ARs) in inhibiting NK92­MI cells­mediated cytotoxicity by NE were investigated. To examine the effect of NE on NK92­MI cytotoxicity, a lactate dehydrogenase­release cytotoxicity assay was used to determine the cytotoxicity of NK92­MI cells against K562 cells. To evaluate the possible function of the α, ß1 and ß2 AR in mediating NE­induced effects, NK92­MI cells were pre­incubated with phenol­amine, CGP20712A and ICI118551 prior to stimulation by NE. To evaluate the role of cyclic adenosine monophosphate (cAMP)­protein kinase A (PKA) signaling pathway in the inhibitory effect on cytotoxicity of NK92­MI cell by NE, NK92­MI cells were pre­incubated with PKA inhibitor Rp­8­Br­cAMP prior to stimulation by NE. It was demonstrated that NE decreased cytotoxicity and downregulated the expression of perforin, granzyme B and interferon (IFN)­Î³ of NK92­MI cells in a dose­dependent manner. Blocking NE functional receptors by ARs antagonists, particularly of ß2 AR antagonist, suppressed the inhibitory effect of NE on cytotoxicity and expression of perforin, granzyme B, IFN­Î³ of NK92­MI cells significantly. Blockade of ß2 AR in NE treated NK92­MI cells resulted in a reduction of the expression of phosphorylated (p)­cAMP­responsive element­binding protein (CREB) and intracellular cAMP concentration. Inhibiting the activity of PKA by Rp­8­Br­cAMP in NE treated NK92­MI cells resulted in increased cytotoxicity. The results of the present study suggest that NE can inhibit cytotoxicity and expression of perforin, granzyme B, IFN­Î³ of NK92­MI cell mainly via the ß2­AR/cAMP/PKA/p­CREB signaling pathway.

Single nucleotide polymorphisms in TNFAIP3 were associated with the risks of rheumatoid arthritis in northern Chinese Han population.

BACKGROUND: Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic destructive inflammation in synovial joints. It is well known that genetic and environmental risk factors and their interaction contribute to RA pathogenesis. This study aimed to investigate the association between the critical polymorphisms in the tumor necrosis factor α (TNFα)-induced protein 3(TNFAIP3) gene and the risk of RA in a large northern Chinese Han population. METHODS: A case-control study of 1280 RA patients and 1280 matched healthy controls was conducted. RESULTS: This study showed that carriers of the rs2230926 TG genotype or rs10499194 CT genotype had an increased risk for RA compared with those carrying the wild genotype (rs2230926: OR = 1.48, 95% CI = 1.17-1.86, p = 0.001; rs10499194: OR = 2.00, 95% CI = 1.46-2.74, p < 0.001). The combined rs2230926TG/GG or rs10499194 CT/TT were associated with an increased risk of RA (ORs were 1.50 and 2.01, 95% CIs were 1.19-1.88 and 1.47-2.74, respectively, both p < 0.001). There was not significant association between rs13207033 polymorphism and RA risk. Subset analysis stratified to gender showed that the increased risks were significant among the genotypes TG, TG/GG of rs2230926 and CT, CT/TT of rs10499194 and the corresponding ORs were 1.42 (95% CI = 1.10-1.83, p = 0.006), 1.44(95% CI = 1.12-1.85, p = 0.004), 1.52(95% CI = 1.05-2.20, p = 0.026) and 1.52(95% CI = 1.06-2.19, p = 0.023) in the female population. Stratified analyses by age found that rs2230926(TG, TG/GG) and rs10499194(CT, CT/TT) polymorphisms were associated with RA risks in population ≤53 years old and among >53 years old only rs10499194(CT, TT, CT/TT) polymorphism had significant results. The interaction analysis suggested that individuals with both risk genotypes of the two SNPs have a higher elevated risk of RA than those with only one of them (ORs were 3.44 compared to 1.74 and 1.35). The haplotype results showed that individuals with the rs2230926G-rs13207033G-rs10499194C haplotype were associated with increased risks of RA (OR = 1.37, 95% CI = 1.08-1.74, p = 0.010). CONCLUSIONS: Rs10499194 and rs2230926 polymorphisms in the TNFAIP3 gene region may be susceptibility factors for rheumatoid arthritis in the northern Chinese Han population.

Phenotypic and functional maturation of murine dendritic cells (DCs) induced by purified Glycyrrhizin (GL).

The aim of this study is to investigate phenotypic and functional modulation of murine dendritic cells (DCs) with use of purified Glycyrrhizin (GL). These impacts of GL on DCs both from bone marrow derived DCs and established DC cell 2.4 were assessed with conventional scanning electron microscopy (SEM), flow cytometry (FCM), transmission electron microscopy (TEM), cytochemistry assay, FITC-dextran, bio-assay and enzyme linked immunosorbent assay (ELISA). We found that the purified GL induced phenotypic maturation as evidenced by increased expression of CD86, CD40, CD80, CD83 and major histocompatibility complex II (MHC II). The functional tests showed the activity of acidic phosphatase (ACP) inside the DCs2.4 cells were down- regulated after treatment with GL (which occurs when phagocytosis of DCs2.4 cells were decreased). Finally, we proved that GL increased the production of IL-12, IL-10 and decreased the production of tumor necrosis factor alpha (TNF-α). These data indicated that GL could promote maturation of DCs and this adjuvant-like activity may have potential therapeutic value. It is therefore concluded that GL could exert positive modulation on murine DCs.

Subchronic effects of perfluorooctanesulfonate exposure on inflammation in adult male C57BL/6 mice.

Previous studies indicate that exposure to perfluorooctanesulfonate (PFOS), a ubiquitous and highly persistent environmental contaminant, induces immunotoxicity in mice. However, few studies have specifically assessed the effects of PFOS on inflammation. This study utilized a standard 60-day oral exposure period to assess the effects of PFOS on the response of inflammatory cytokines [tumor necrosis factor α (TNF-α), interleukin-1 ß (IL-1ß), and interleukin-6 (IL-6)]. Adult male C57BL/6 mice were dosed daily by oral gavage with PFOS at 0, 0.0083, 0.0167, 0.0833, 0.4167, 0.8333 or 2.0833 mg/kg/day to yield a targeted Total Administered Dose (TAD) over 60 days of 0, 0.5, 1, 5, 25, 50, or 125 mg PFOS/kg, respectively. The percentage of peritoneal macrophages (CD11b+ cells) was significantly increased at concentrations ≥ 1 mg PFOS/kg TAD in a dose-dependent manner. Ex vivo IL-1ß production by peritoneal macrophages was elevated substantially at concentrations of ≥ 5 mg PFOS/kg TAD. Moreover, PFOS exposure markedly enhanced the ex vivo production of TNF-α, IL-1ß and IL-6 by peritoneal and splenic macrophages when stimulated either in vitro or in vivo with lipopolysaccharide (LPS). The serum levels of these inflammatory cytokines observed in response to in vivo stimulation with LPS were elevated substantially by exposure to PFOS. PFOS exposure elevated the expression of pro-inflammatory cytokines TNF-α, IL-1ß, IL-6, and proto-oncogene, c-myc, in the spleen. These data suggest that exposure to PFOS modulates the inflammatory response, and further research is needed to determine the mechanism of action.

The modifier protein of glyceraldehyde-3-phosphate dehydrogenase reduces free radical-mediated renal damage in a rat model of acute kidney injury.

BACKGROUND: The modifier protein (MP) of glyceraldehyde-3-phosphate dehydrogenase has been shown to promote growth of renal epithelial cells in vitro. The aim of this study was to show the in vivo effects of MP in a rat model of gentamicin-induced acute kidney injury (AKI). METHOD: MP was purified from monkey renal tubular epithelial cell line BSC-1 and confirmed by amino acid sequencing. Male Sprague-Dawley rats were divided into the following groups: normal control, gentamicin-treated, epidermal growth factor (EGF) plus gentamicin-treated, and MP plus gentamicin-treated, as well as control groups for EGF and MP alone. Levels of serum creatinine (SCr), serum and tissue lipid peroxide, nitric oxide and glutathione-S-hydrogenase for each group were measured on the 7th and 14th days of treatment. Tissue sections were studied with light microscopy. RESULTS: The gentamicin-treated group showed a marked increase in SCr compared to the normal control group. Co-treatment of gentamicin with MP and/or EGF produced similar significant decreases preventing the increase in SCr. There were also significant reductions in serum and tissue homogenate levels of lipid peroxide and nitric oxide, accompanied by an increase in the level of glutathione-S-hydrogenase, in the MP co-treated groups compared to the gentamicin-treated group. AKI was confirmed histologically in the gentamicin-treated group, with damage to the tubular epithelium recorded. This was attenuated by MP co-treatment. There were also reductions in the expression of intercellular adhesion molecule-1 and proliferating cell nuclear antigen in the MP co-treated groups. CONCLUSION: Using a gentamicin model of AKI, MP was able to reduce free radical production in kidney tissue and in the circulation, thus preventing oxidant injury and minimizing damage in renal epithelial cells.

[The influence of the extract of lumbricus on the production of NO and TNF-alpha by mouse MPhi and splenocytes].

AIM: To explore the effect of the abstracts of lumbricus on the secretion of NO and TNF-alpha by mouse Mphi s and splenocytes. METHODS: Murine Mphi s and spleen cell were co-cultured with various doses of lumbricus abstracts for 24 hours and then the supernate was collected. The levels of NO and TNF-alpha were detected by diazotization reaction and MTT colorimetry, respectively. RESULTS: Compared with control group, 0.1 g/L of lumbricus abstracts could increase the NO level and antagonize the inhibition of dexamethasone(Dex). 1 x 10(-4), 1 x 10(-3) g/L of lumbricus abstracts could increase TNF-alpha level and also antagonize the inhibition of Dex on the secretion of TNF-alpha by Mphi s and splenic cells. CONCLUSION: The abstracts of lumbricus can activate Mphi s and splenic cells to secrete NO and TNF-alpha and antagonize the inhibition effect of Dex on these cells.