CysLT2受体拮抗剂HAMI3379抑制LPS诱导小鼠小胶质瘤细胞系的炎性反应

目的探究半胱氨酰白三烯2(CysLT2)受体拮抗剂HAMI3379对LPS诱导小鼠小胶质细胞(BV-2)炎性反应的调控作用及其可能的作用机制。方法体外培养BV-2,将BV-2分为对照组、LPS(100 ng/mL)组、HAMI3379(0.01、0.1和1μmol/mL)组和LPS+HAMI3379组。CCK-8法检测BV-2细胞的增殖;ELISA检测细胞上清液中炎性因子IL-1β、TNF-α、IL-10的含量;Western-blot检测PKCα、IKBα、NF-κB p50和p65蛋白的表达。结果LPS能够激活BV-2细胞,促进其细胞的增殖(P<0.05);显著增加细胞上清液中炎性因子IL-1β、TNF-α的分泌,减少IL-10的分泌(P<0.05);且显著上调PKCα、IKBα、p65蛋白的表达水平(P<0.05)。CysLT2受体拮抗剂HAMI3379能够显著减轻上述变化(P<0.05)。结论CysLT2受体拮抗剂HAMI3379能够抑制LPS激活BV-2细胞,抑制炎性反应,其作用机制可能与抑制PKCα/NF-κB信号通路有关。     

Albaconol, a plant-derived small molecule, inhibits macrophage function by suppressing NF-kappaB activation and enhancing SOCS1 expression

Discovery and functional identification of plant-derived small compounds as the immunosuppressant attract much attention these years. Albaconol is a new kind of small compound, prenylated resorcinol, isolated from the fruiting bodies of the inedible mushroom Albatrellus confluens. Our previous studies showed that albaconol can inhibit tumor cell growth and dendritic cell maturation. However, the immunomodulatory roles and the underlying mechanisms of albaconol have not been fully understood. In this study we investigated the effects of albaconol on the proliferation and LPS-induced proinflammatory cytokine production of macrophages. Albaconol, when used at a dose higher than 1.0 μg/ml, inhibited proliferation of RAW264.7 cells in a doseand time-dependent manner, and could induce cellular apoptosis when used at high dosage （≥7.5 μg/ml）. Furthermore, we found that albaconol used at a lower dosage without apoptosis induction could significantly inhibit LPS-induced TNF-α IL-6, IL-1β and NO production in RAW264.7 cells. The inhibition of NF-κB activation and enhancement of SOCS1 expression in LPS-stimulated macrophages by albaconol may contribute to the above immunosuppressive or anti-inflammatory activities of albaconol. Our results suggest that albaconol may be a potential immunosuppressive and anti- inflammatory drug. Cellular ＆ Molecular Immunology. 2008;5（4）：271-278.     

肝细胞特异性Sirt1缺失加重小鼠肝脏炎性反应

目的探究沉默信息调节因子1 (Sirt1)基因的缺失对小鼠肝脏炎性反应的影响及其作用机制。方法每周记录在高脂喂养下的野生型C57BL/6J雄性小鼠和肝脏特异性Sirt1敲除(Sirt1-LKO)雄性小鼠的体质量,用Western blot和q-PCR检测炎性因子的表达;给小鼠腹腔注射20 mg/kg LPS,用生存曲线来反映小鼠对炎性反应的敏感性。结果与对照组WT小鼠相比,Sirt1-LKO小鼠表现为体质量明显减轻(P<0.05)。另外,生存曲线KaplaneMeier图显示Sirt1-LKO小鼠对LPS刺激呈现低敏感性(P<0.05)。Sirt1-LKO小鼠原代肝细胞中NF-κB蛋白水平增高(P<0.05),及NF-κB下游靶基因炎性因子Tnfα和IL6明显上调(P<0.05)。结论肝细胞特异性Sirt1缺失加重肝脏炎性反应。     

Atractylenolide I inhibits lipopolysaccharide-induced inflammatory responses via mitogen-activated protein kinase pathways in RAW264.7 cells

Atractylenolide I (ATL-I) is a bioactive component of Rhizoma Atractylodis macrocephalae. Although increasing evidence shows that ATL-I has an anti-inflammatory effect, the anti-inflammatory molecular mechanism of ATL-I is still unknown. In this study, we investigated the effect of ATL-I on cell viability by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay and the level of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) by enzyme-linked immunosorbent assay (ELISA) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Further, we examined the effect of ATL-I on the activation of nuclear factor-kappaB (NF-κB) and phosphorylation of extracellular signal regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (p38) by Western blot. We also investigated the effect of ATL-I on the expression of myeloid differentiation protein-2 (MD-2), CD14, complement receptor 3 (CR3), scavenger receptor class A (SR-A), toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88). We found that ATL-I showed no inhibitory effect on cell viability at concentrations ranging from 1?µM to 100?µM and markedly reduced the release of IL-6 and TNF-α at a concentrate-dependent manner. In addition, ATL-I suppressed the activity of nuclear NF-κB and the phosphorylation of ERK1/2 and p38 in LPS-treated RAW264.7 cells. Further analysis showed that ATL-I inhibited the expression of MD-2, CD14, SR-A, TLR4 and MyD88, but the expression of CR3 was unaffected. These data suggest that ATL-I shows an anti-inflammatory effect by inhibiting TNF-α and IL-6 production. The anti-inflammatory effects of ATL-I may be associated with the inhibition of the NF-κB, ERK1/2 and p38 signaling pathways.     

卡维地洛对高血压大鼠主动脉的保护作用

目的 :研究卡维地洛对核因子 κB(NF κB)、单核细胞趋化蛋白 1(MCP 1)在自发性高血压大鼠 (SHR)大血管中表达的影响 ,探讨其对血管保护的机制。方法 :18只雄性 12周龄SHR随机分为阳性组 ,卡维地洛组 ( 30mg/kg·d) ,美托洛尔组 ( 50mg/kg·d) ,灌喂 8周 ;另选同龄雄性WistarKyoto大鼠为阴性组 (n =6 )。用免疫组化法测各组主动脉NF κB、MCP 1的表达 ,ELISA法测血清MCP 1含量。结果 :与阴性组比较 ,阳性组主动脉组织中NF κB、MCP 1表达增加 (P<0 .0 1) ,且两者正相关 (r=0 .72 8,P <0 .0 1) ;血清MCP 1含量升高 1.6 4(P <0 .0 1)。 8周后 ,治疗组之间血压无明显差异 (P >0 .0 5) ,但卡维地洛更显著抑制NF -κB、MCP 1表达 (P <0 .0 5)。结论 :卡维地洛可能独立于降压外抑制NF κB的活化来调控MCP 1表达。     

SB203580 enhances interleukin-1 receptor antagonist gene expression in IFN-gamma-stimulated BV2 microglial cells through a composite nuclear factor-kappaB/PU.1 binding site

Interleukin-1 receptor antagonist (IL-1ra) is a naturally occurring antagonist of IL-1alpha and IL-1beta binding to the IL-1 receptors and alleviates various inflammatory reactions. Therefore, the upregulation of IL-1ra expression is important for preventing and/or treating inflammatory diseases including many neurodegenerative diseases. This study found that SB203580, which is generally known as a p38 MAP kinase inhibitor and an anti-inflammatory agent, increased the level of IL-1ra expression in IFN-gamma-stimulated BV2 microglial cells. This effect is believed to occur through the inhibition of protein kinase B (PKB), independently of the p38 MAP kinase pathways. Further mechanistic studies using an IL-1ra promoter revealed that a composite NF-kappaB/PU.1 binding site plays an important role in this SB203580-mediated upregulation of IL-1ra. Considering that IFN-gamma is a major stimulator of the innate and adaptive immune responses, the upregulation of anti-inflammatory IL-1ra expression by SB203580 in the IFN-gamma-stimulated microglia might provide a new therapeutic modality for various inflammatory diseases of the central nervous system.     

Tubeimoside-1 inhibits the proliferation and activation of mouse T lymphocytes through signal transduction pathways

Abstract

Tubeimoside-1 (TBMS1) is one of the important components in Bolbostemma paniculatum (Maxim.) Franque. In the study, its immunosuppressive effects on murine T lymphocyte responses were evaluated in vitro and in vivo. The data showed that TBMS1 inhibited ConA-induced T lymphocyte proliferation, decreased the ratio of CD4⁺/CD8⁺, suppressed IL-2, IFN-γ, IL-4 and IL-6 production and mRNA expression, down-regulate activation of NF-κB, NFAT2 and AP-1 signal transduction pathways in vitro. In addition, administration of TBMS1 significantly inhibited T cell-mediated DTH response in vivo. These findings indicated that TBMS1 inhibits the proliferation and activation of T lymphocytes in mice.     

Dihydroartemisinin suppresses ovalbumin-induced airway inflammation in a mouse allergic asthma model

Abstract

Asthma is a complex disease characterized by reversible airway obstruction, airway hyper-responsiveness (AHR) and chronic inflammation of the airways. Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua, has been shown to possess antimalarial and antitumor activities, but whether it can be used in asthma treatment has not been investigated. In this study, we attempted to determine whether DHA regulates inflammatory mediators in the ovalbumin (OVA)-induced mouse asthma model. BALB/c mice were sensitized and challenged by OVA to induce chronic airway inflammation. The intragastrical administration of DHA at 30?mg/kg significantly decreased the number of infiltrating inflammatory cells, T-helper type 2 (Th2) cytokines, OVA-specific immunoglobulin E (IgE) and AHR. Treatment with DHA also attenuated OVA-induced mRNA expression of Muc5ac and chitinase 3-like protein 4 (Ym2) in lung tissues. In addition, lung histopathological studies revealed that DHA inhibited inflammatory cell infiltration and mucus hypersecretion. Then signal transduction studies showed that DHA significantly inhibited extracellular signal-regulated protein kinase (ERK), p38 mitogen-activated protein kinase phosphorylation. DHA also inhibited nuclear factor-κB (NF-κB) activation via the inhibition of phosphorylation of IκBα. These findings provide new insight into the immunopharmacological role of DHA in terms of its effects in a mouse model of asthma.     

Role of Toll-like receptor 4 in hyperoxia-induced lung inflammation in mice

Objective: Prolonged exposure to hyperoxia causes lung inflammation, but the role of Toll-like receptor 4 (TLR4) in hyperoxia-induced signal transduction remains unclear. Material or subjects: We evaluated neutrophil accumulation, signal transduction and cytokine production during hyperoxia, comparing TLR4 mutant (C3H/HeJ) and wild type (C3H/HeN) mice. Methods: The mice were exposed to 80% oxygen in a hyperoxic chamber for 0 (control), 48, or 96 h. After the exposure, bronchoalveolar lavage (BAL) was performed for differential cell counting and cytokine measurement. In lung homogenate, activation of NF-κB and STAT1 was also examined. Results: In C3H/HeJ mice, hyperoxia-induced neutrophil accumulation in BAL fluid was significantly decreased compared with C3H/HeN. Hyperoxia for 96 h caused NF-κB translocation in C3H/HeN mice, which was significantly attenuated in C3H/HeJ mice (p < 0.05). In contrast, STAT1 activation occurred as early as after 48 h of oxygen exposure, which did not differ between the two strains. The levels of TNF-α, IL-6, and KC in BAL fluid were increased after oxygen exposure, which was suppressed by the lack of TLR4 signaling. Conclusion: These results suggest that TLR4-dependent NF-kB activation may be an important process of the upregulation of proinflammatory mediators and subsequent neutrophil accumulation into the lung during hyperoxia. Received 21 March 2007; accepted without revision by G. Wallace 11 April 2007     

Norepinephrine inhibits human immunodeficiency virus type-1 infection through the NF-kappaB inactivation

Exercise or acute stress can exert significant effects on immune system as well as cardiovascular and respiratory systems through catecholamines. In this study, we investigated effects of norepinephrine (NE), a catecholamine neurotransmitter on human immunodeficiency virus type-1 (HIV-1) infection. NE inhibited in vitro HIV-1 infection of peripheral blood mononuclear cells (PBMC) from healthy donors and ex vivo HIV-1 replication in patients' PBMC. In transient expression assays, NE downregulated HIV-1 long terminal repeat, but site-directed mutagenesis on NF-kappaB-binding sites or cotreatment with H89 (a protein kinase A inhibitor) abrogated the NE-mediated effect. Gel-shift assays showed suppression of NF-kappaB activity in NE-treated cells. NE increased cytoplasmic levels of IkappaB-alpha, a natural inhibitor of NF-kappaB. Thus, NE apparently inhibits HIV-1 infection, at least in part through NF-kappaB inactivation.     

Repeated administration of mirtazapine inhibits development of hyperalgesia/allodynia and activation of NF-kappaB in a rat model of neuropathic pain

Antidepressants have been widely used to treat neuropathic pain for many years. However, the mechanisms of their analgesic actions are little known and remain controvertible. Recent studies indicate that cytokines in central nervous system (CNS) play a critical role in the pathological states of pain. The present study was designed to explore the effects and most appropriate dosage of mirtazapine in treating neuropathic pain and its possible neuroimmune mechanisms. L5 spinal nerve transection was done to produce hyperalgesia in rats. Mirtazapine (10, 20 and 30 mg/kg, respectively) was orally administered daily for 14 days, beginning from the 5th day after nerve transection. Mechanical and thermal hyperalgesia was measured using Von-Frey filament and Hargreaves tests before and after the surgery. Rats were then sacrificed on days 3, 7, 14, 21 post-administration. The inflammatory cytokines production such as TNFalpha, IL-1beta, IL-10 and nuclear factor kappa B (NF-kappaB) activity in brain was quantified using enzyme-linked immunosorbent assay (ELISA) and electrophoretic mobility shift assay (EMSA). We found that mirtazapine (20 and 30 mg/kg) can markedly attenuate mechanical and thermal hyperalgesia produced by nerve transection, most significantly on the 14th day. The elevated TNFalpha, IL-1beta and NF-kappaB in brain were accordingly reduced, while the expression of increased IL-10 were even stimulated after repeated mirtazapine administration. Our data could conclude that mirtazapine suppressed neuropathic pain partially through inhibiting cerebral proinflammatory cytokines production and NF-kappaB activation in CNS.     

The zinc finger protein Miz1 suppresses liver tumorigenesis by restricting hepatocyte-driven macrophage activation and inflammation

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Sublethal necroptosis signaling promotes inflammation and liver cancer

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Anti-Inflammatory Mechanism of a Folk Herbal Medicine,Duchesnea indica (Andr) Focke at RAW264.7 Cell Line

This study is to explore the anti-inflammatory mechanism of the ethanol extract of Duchesnea indica (Andr) Focke. An inflammatory cellular model was established by addition of lipopolysaccharide (LPS) on RAW264.7 cell line. The cellular secretion of TNF-α, IL-1β, IL-6, NO and IL-10 in supernatant, mRNA expression of TNF-α, COX-2, iNOS and HO-1, protein expression of COX-2 and HO-1, and activation of NF-κB were assayed by ELISA, the Griess method, real-time quantitative PCR, and Western blot and immunocytochemistry method, respectively. The ethanol extract of D. indica not only reduced production of pro-inflammatory cytokines and mediators and blocked NF-κB activation, but also slightly promoted release of the anti-inflammatory mediator HO-1 and suppressed IL-10 secretion. In conclusion, the anti-inflammatory effects of the extract of D. indica are attributed to the suppression of pro-inflammatory cytokines and mediators by blocking NF-κB activation. The extract of D. indica can also slightly promote HO-1 production to reduce inflammation.     

Montelukast, a leukotriene receptor antagonist abrogates lipopolysaccharide-induced toxicity and oxidative stress in rat liver

Endotoxemia-induced hepatotoxicity is characterized by disturbed intracellular redox balance, excessive reactive oxygen species (ROS) generation inducing DNA, proteins and membrane lipid damages. In the present study, the protective effects of montelukast (MNT) against Escherichia coli lipopolysaccharides (LPS)-induced oxidative stress were investigated in rat liver. LPS (10 mg/kg, i.p.) was injected and the animals were sacrificed 6 h after LPS challenge. MNT (10 mg/kg) was administered orally for seven successive days before endotoxemia induction. Blood samples were withdrawn for assessing the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and levels of serum total bilirubin, total protein, tumor necrosis factor-alpha (TNF-α) and interleukin 1β (IL-1β). Livers were dissected out and used for histological examination or stored for the determination of malondialdehyde (MDA), protein carbonyl content (PCC), reduced glutathione (GSH) levels, enzymatic activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and myeloperoxidase (MPO). Sepsis significantly increased ALT, AST, ALP, LDH, total bilirubin, TNF-α and IL-1β, MPO, MDA and PCC levels and decreased total protein, GSH and enzymatic antioxidants (CAT, SOD and GSH-Px). MNT decreased the markers of liver injury (AST, ALT, ALP, LDH, and total bilirubin), inflammatory biomarkers (TNF-alpha, IL-1β), MDA, PCC and MPO after LPS challenge. In conclusion, MNT abrogates LPS-induced markers of liver injury and suppresses the release of inflammatory and oxidative stress markers via its antioxidant properties and enhancement enzymatic antioxidant activities.