雷公藤红素对IL—1和IL—2活性及PGE2释放的抑制作用

雷公藤红素0.1～1.0μg/ml在试管内能降低LPS诱导的小鼠腹腔巨噬细胞外和细胞内白细胞介素-1(IL-1)的活性,也能抑制ConA诱导的小鼠脾细胞产生白细胞介素-2(IL-2).动态观察表明,雷公藤红素经预处理8h和3h后已能分别抑制IL-1和IL-2的产生。此外,雷公藤红素能降低A23187刺激家兔滑膜细胞释放前列腺素E_2(PGE_2)。     

异丹叶大黄素和白藜芦醇对小鼠腹腔巨噬细胞白细胞介素6 mRNA表达的影响

目的：观察异丹叶大黄素和白藜芦醇对分别由炎性三肽(fMLP)和钙离子载体A₂₃₁₈₇(A₂₃₁₈₇)诱导的小鼠腹腔巨噬细胞白细胞介素6(interleukin 6, IL-6) mRNA表达水平的影响。方法：用半定量mRNA的RT-PCR。结果：异丹叶大黄素和白藜芦醇在2×10^-6和2×10^-5 mol.L^-1浓度下,均能抑制fMLP和A₂₃₁₈₇诱导的小鼠腹腔巨噬细胞IL-6 mRNA的表达。结论：该2个化合物抑制IL-6活性的作用机制之一是抑制IL-6 mRNA表达。     

壮药透骨香抗类风湿关节炎药物活性部位筛选及机制研究

目的 探讨壮药透骨香抗类风湿关节炎作用的药物活性部位及作用机制。方法 体外培养法制备BALB/c小鼠脾淋巴细胞,经刀豆蛋白A（CoA）刺激作用后,以透骨香各药物部位进行干预, 细胞计数试剂盒-8（CCK-8）法检测细胞增殖情况,计算刺激指数;体外培养小鼠脾细胞,刀豆蛋白A刺激T淋巴细胞增殖,采用酶联免疫吸附实验（ELISA）法检测观察透骨香活性部位对细胞因子白细胞介素-2（IL-2）、白细胞介素-10（IL-10）含量的影响。结果 小鼠脾细胞经刀豆蛋白A刺激后,细胞计数试剂盒-8检测光密度（OD）值与刺激指数显著升高（P＜0.05）,透骨香正丁醇部位及水溶部位能明显降低光密度值及刺激指数,其中水溶部位（5 μg·mL^-1）作用最强（P＜0.05）;刀豆蛋白A刺激脾淋巴细胞增殖后,细胞因子白细胞介素-2、白细胞介素-10分泌显著增强,透骨香水溶部位干预后能明显抑制白细胞介素-2分泌,提高白细胞介素-10含量（P＜0.05）。结论 透骨香水溶部位对T淋巴细胞增殖具有较强抑制作用,是透骨香抗RA活性部位,其机制可能与调节细胞因子白细胞介素-2、白细胞介素-10分泌有关。     

商陆多糖Ⅰ联合白细胞介素2对小鼠脾细胞杀瘤活性的影响

商陆多糖Ⅰ(PAP-I),0.3～3μg·ml^-1和小鼠脾细胞培养3～5d可显著增强其杀伤P815肿瘤细胞活性及IL-2(250～500IU·ml^-1)诱导的LAK细胞活性,最适浓度为1μg·ml^-1。PAP-I及IL-2和脾细胞培养的上清液对P815肿瘤细胞无细胞毒作用,但能增强脾细胞及LAK细胞杀瘤活性。PAP-I,5,10及50mg·kg-1,ip可增强脾细胞杀伤P₈₁₅和L₉₂₉细胞的活性及IL-2诱导的LAK细胞活性。     

人参皂甙Rg1对老年大鼠免疫功能的调节作用

已知老年机体免疫功能的降低与淋巴细胞增殖能力的减弱和白细胞介素-2(IL-2)产生减少有密切关系。以老年大鼠免疫功能为主要研究对象,首次发现人参皂甙Rg1无论体内给药还是体外实验均能选择性增强老年大鼠脾淋巴细胞增殖能力和IL-2的产生与释放,采用Northern和Western印迹分析法证明,Rg₁可明显促进IL-2基因和蛋白的表达,表现在IL-2mRNA和IL-2蛋白含量的显著增加。值得注意的是,在同样的条件下,Rg₁对青年大鼠免疫功能的影响并不显著,由此可以认为Rg1一种“免疫调节剂”,而并非单纯的“免疫增强剂”。     

白头翁皂苷B4对咪喹莫特诱导的小鼠银屑病的治疗作用及其机制研究

目的 考察白头翁皂苷B₄对咪喹莫特诱导的银屑病模型小鼠的炎症及免疫相关指标的影响,探讨其对小鼠银屑病的治疗作用及其机制。方法 将56只BALB/c小鼠随机分成对照组,模型组,阿维A胶囊组（6 mg/kg）,白头翁皂苷B₄低、中、高剂量（5、10、20 mg/kg）组,白头翁皂苷B₄乳膏组（20 mg/kg）,每组各8只。通过局部涂抹5%咪喹莫特乳膏诱导小鼠银屑病模型,各组小鼠口服或涂抹相应药物,14 d后通过银屑病皮损面积及严重程度评分（PASI）评价小鼠皮损程度;HE染色观察皮肤组织病理学形态;血常规检测血液中免疫细胞的变化;酶联免疫吸附试剂（ELISA）检测小鼠皮肤中白细胞介素（IL）-6、IL-12、IL-17、IL-1β的水平。结果 与模型组相比,阿维A胶囊组,白头翁皂苷B₄ 5、10、20 mg/kg组,白头翁皂苷B₄乳膏组小鼠皮损组织棘层厚度减小,真皮层炎症细胞浸润减少,PASI评分、血液中的免疫细胞及皮肤组织中IL-6、IL-12、IL-17、IL-1β的表达水平均显著降低。结论 白头翁皂苷B₄对5%咪喹莫特诱导小鼠银屑病皮损具有明显的治疗作用,其机制可能是通过抑制IL-6、IL-12、IL-17、IL-1β等细胞因子表达发挥治疗作用。     

白芍总甙对白细胞介素-2产生的影响

白芍总甙(0.5～62.5mg/L)对ConA(3mg/L)诱导的大鼠脾细胞产生白细胞介素-2具有双向调节作用。同时用活化小鼠脾细胞检测了ConA诱导大鼠脾细胞产生白细胞介素-2的纯度,表明,主要以白细胞介素-2为主。     

大网膜脂质血管生长因子对体外小鼠脾细胞增殖及白细胞介素-2产生水平的影响

研究了经超声乳化的大网膜脂质血管生长因子对体外小鼠脾细胞增殖及经ConA诱导产生的白细胞介素-2水平的影响。结果显示：此因子能明显抑制体外小鼠脾细胞的增殖且降低白细胞介素-2的产生水平，而对照的皮下脂肪抽援物则无此效应。同时也观察到乳化剂Tween80有轻微的细胞毒性。     

IL-2基因修饰对树突状细胞表面粘附分子的影响

为研究白细胞介素 2 (IL -2 )基因修饰后对树突状细胞 (DC)表面粘附分子的变化 ,分析白细胞介素 -2对树突状细胞的活化作用。制备小鼠骨髓树突状细胞 ,用重组腺病毒介导白细胞介素 -2基因修饰 ,通过流式细胞仪分析树突状细胞表型特征。结果 ,树突状细胞经IL -2基因修饰后 ,能分泌高水平的白细胞介素 -2〔3.2 5ng·(1× 1 0 6)·m1 - 1·2 4h- 1〕 ,其表面MHC -Ⅱ、B7-1、B7-2和CD4 0表达明显上调。提示IL -2基因修饰树突状细胞 ,能促进树突状细胞的成熟 ,上调树突状细胞表面与抗原提呈相关的免疫粘附分子的表达     

丙泊酚全麻对胆道手术患者血清IL-2和IL-6的影响

目的 探讨七氟烷吸入全麻或丙泊酚全凭静脉全麻对胆道手术患者围术期血清细胞因子IL-2和IL-6的影响。方法 30例择期行开腹胆道手术患者,随机分入七氟烷吸入全麻组(S组)或丙泊酚全凭静脉全麻组(P组),每组各15例。分别于麻醉诱导前(T₀)、术毕(T₁)、术后24h(T₂)、术后72h(T₃)采集静脉血3ml,酶标法测定血清IL-2、IL-6水平。结果 与T₀时段相比,两组T₁时段血清IL-2显著下降(P＜0.05),而两组T₁、T₂时段血清IL-6显著升高(P＜0.05)。T₁时段S组与P组比较,血清IL-6的显著升高(P＜0.05)。结论 七氟烷和丙泊酚对血清IL-2水平变化影响无显著差别。丙泊酚全凭静脉全麻显著抑制血清IL-6水平升高,抑制手术麻醉应激引起的免疫反应。     

Prostaglandin E<Subscript>2</Subscript>-mediated dysregulation of proinflammatory cytokine production in pristane-induced lupus mice

Systemic lupus erythematosus (SLE) is characterized by inflammatory and dysregulatory immune responses including overactive B cells, overproduction of proinflammatory cytokines, and T cell hyperactivity. PGE₂ modulates a variety of immune processes at sites of inflammation, including production of inflammatory cytokines. However, the role of PGE₂ in dysregulatory inflammatory and immune responses in lupus remains unclear. We investigated whether PGE₂ mediates production of inflammatory cytokines in pristane-induced lupus BALB/c mice. Our results showed that levels of serum and BAL PGE₂ and LPS-stimulated production of PGE₂ by peritoneal macrophages were remarkably increased in pristane-induced lupus mice compared to healthy controls. Exogenous PGE₂ enhanced production of IL-6, IL-10, and NO but decreased TNF-α by macrophages and augmented IFN-γ, IL-6, and IL-10 by splenocytes from pristane-induced lupus mice compared to healthy controls. Exogenous PGE₂ also enhanced production of IFN-γ, IL-6, and IL-10 by thymocytes from pristane-induced lupus mice. Indomethacin (Indo), a PGE₂ synthesis inhibitor, greatly inhibited LPS-induced production of IL-6 and IL-10 by macrophages from pristane-induced lupus mice, while enhanced TNF-α. Indo remarkably inhibited Con A-increased production of IFN-γ, IL-6, and IL-10 by splenocytes and thymocytes from pristane-induced lupus mice. Therefore, our findings suggest that endogenous PGE₂ may mediate dysregulation of production of proinflammatory cytokines, such as IL-6, IL-10, and IFN-γ, and NO in pristane-induced lupus mice.     

Prostaglandin E2-loaded microspheres as strategy to inhibit phagocytosis and modulate inflammatory mediators release

PGE₂, an arachidonic acid metabolite produced by various type of cells regulates a broad range of physiological activities in the endocrine, cardiovascular, gastrointestinal, and immune systems, and is involved in maintaining the local homeostasis. In the immune system, PGE₂ is mainly produced by APCs and it can suppress the Th1-mediated immune responses. The aim of this study was to develop PGE₂-loaded biodegradable MS that prolong and sustain the in vivo release of this mediator. An o/w emulsion solvent extraction–evaporation method was chosen to prepare the MS. We determined their diameters, evaluated the in vitro release of PGE₂, using enzyme immunoassay and MS uptake by peritoneal macrophages. To assess the preservation of biological activities of this mediator, we determined the effect of PGE₂ released from MS on LPS-induced TNF-α release by murine peritoneal macrophages. We also analyzed the effect of encapsulated PGE₂ on inflammatory mediators release from HUVECs. Finally, we studied the effect of PGE₂ released from biodegradable MS in sepsis animal model. The use of this formulation can provide an alternative strategy for treating infections, by modulating or inhibiting inflammatory responses, especially when they constitute an exacerbated profile.     

Prostaglandin E2 couples through EP4 prostanoid receptors to induce IL-8 production in human colonic epithelial cell lines

Background and purpose:

Prostaglandin (PG) E₂ and interleukin (IL)-8 are simultaneously increased during the inflammation that characterizes numerous pathologies such as inflammatory bowel disease. IL-8 is a potent neutrophil chemo-attractant and activator, and can initiate and/or exacerbate tissue injury. PGE₂ signals principally through prostanoid receptors of the EP₂ and/or EP₄ subtypes to promote cAMP-dependent cellular functions. The aim of this study was to identify the role of the EP₂ and EP₄ receptor subtype(s) on two human colonic epithelial cell lines (Caco-2 and T84), in regulating PGE₂-induced IL-8 production.

Experimental approach:

To identify the causative receptor, we knocked-down and over-expressed EP₂ and EP₄ receptor subtypes in colonic epithelial cells and studied the effect of several selective EP₂/EP₄ receptor agonists and antagonists. The inductions of IL-8 and EP receptor mRNA and protein expression were determined by real-time PCR and western blot analysis. The affinity of PGE₂ and Bmax values for the EP₂ and EP₄ receptor on colonic epithelial cells were determined by radioligand-binding assays with [³H]PGE₂.

Key results:

PGE₂ had the highest affinity for the EP₄ receptor subtype and promoted a robust stimulation of cAMP-dependent IL-8 synthesis. This effect was mimicked by a selective EP₄ receptor agonist, ONO-AE1-329, and abolished by silencing the EP₄ receptor gene by using siRNA techniques, a selective EP₄ receptor antagonist (ONO-AE3-208) and a selective inhibitor (Rp-cAMP) of cAMP-dependent protein kinase.

Conclusions and implications:

These findings suggest that initiation and progression of colonic inflammation induced by IL-8 could be mediated, at least in part, by PGE₂ acting via the EP₄ receptor subtype.     

Effects of Meloxicam,Compared with other NSAIDs,on Cartilage Proteoglycan Metabolism,Synovial Prostaglandin E2, and Production of Interleukins 1, 6 and 8, in Human and Porcine Explants in Organ Culture

Some non-steroidal anti-inflammatory drugs (NSAIDs) can accelerate joint damage in osteoarthritis by enhancing the production of pro-inflammatory cytokines or inhibiting cartilage proteoglycan synthesis. Meloxicam, a new NSAID, was compared with standard NSAIDs for its effect on proteoglycan synthesis and degradation in human and porcine cartilage explants, as well as the production of prostaglandin E₂ (PGE₂) and interleukins 1 and 6 by human synovial tissue explants in-vitro. Meloxicam at submicromolar concentrations inhibited synovial PGE₂ production but, up to therapeutic drug concentrations (≤ 4 μm ), did not affect synovial production of the pro-inflammatory cytokine IL-1. In contrast, hydrocortisone, 10 μm , a positive control, inhibited release of this cytokine, and indomethacin, 100 μm , increased its production. The lack of effects of meloxicam were evident irrespective of intrinsic IL-1 bioactivity of the synovia, production of IL-1 inhibitors or time of incubation. Production of the part antiinflammatory cytokine IL-6, was significantly increased by therapeutic concentrations of meloxicam, as well as by indomethacin. Another major pro-inflammatory cytokine, IL-8, was unaffected by therapeutic concentrations of meloxicam. Meloxicam, 0.1–4.0 μm , did not affect cartilage proteoglycan production whereas indomethacin, 100 μm , significantly reduced synthesis of these macromolecules. Thus meloxicam, at concentrations within the therapeutic range and at which pronounced inhibition of prostaglandin production is evident, affects neither cartilage proteoglycan production nor the production of those cytokines likely to be important in cartilage destruction.     

Isoliquiritigenin,a flavonoid from licorice,blocks M2 macrophage polarization in colitis-associated tumorigenesis through downregulating PGE2 and IL-6

M2 macrophage polarization is implicated in colorectal cancer development. Isoliquiritigenin (ISL), a flavonoid from licorice, has been reported to prevent azoxymethane (AOM) induced colon carcinogenesis in animal models. Here, in a mouse model of colitis-associated tumorigenesis induced by AOM/dextran sodium sulfate (DSS), we investigated the chemopreventive effects of ISL and its mechanisms of action. Mice were treated with AOM/DSS and randomized to receive either vehicle or ISL (3, 15 and 75 mg/kg). Tumor load, histology, immunohistochemistry, and gene and protein expressions were determined. Intragastric administration of ISL for 12 weeks significantly decreased colon cancer incidence, multiplicity and tumor size by 60%, 55.4% and 42.6%, respectively. Moreover, ISL inhibited M2 macrophage polarization. Such changes were accompanied by downregulation of PGE₂ and IL-6 signaling. Importantly, depletion of macrophages by clodronate (Clod) or zoledronic acid (ZA) reversed the effects of ISL. In parallel, in vitro studies also demonstrated that ISL limited the M2 polarization of RAW264.7 cells and mouse peritoneal macrophages with concomitant inactivation of PGE₂/PPARδ and IL-6/STAT3 signaling. Conversely, exogenous addition of PGE₂ or IL-6, or overexpression of constitutively active STAT3 reversed ISL-mediated inhibition of M2 macrophage polarization. In summary, dietary flavonoid ISL effectively inhibits colitis-associated tumorigenesis through hampering M2 macrophage polarization mediated by the interplay between PGE₂ and IL-6. Thus, inhibition of M2 macrophage polarization is likely to represent a promising strategy for chemoprevention of colorectal cancer.     

Promotion of interferon-gamma production by natural killer cells via suppression of murine peritoneal macrophage prostaglandin E2 production using intravenous anesthetic propofol

Propofol is an intravenous anesthetic, widely used for general anesthesia during surgery, which inevitably involves tissue trauma with inflammation. At sites of inflammation, prostanoids, especially prostaglandin E₂ (PGE₂), are abundant. This study addresses the effect of propofol on macrophage PGE₂ production. Using thioglycollate-elicited murine peritoneal macrophages, propofol (7.5–30 μM) suppressed lipopolysaccharide-induced PGE₂ production. The suppression was via the direct inhibition of cyclooxygenase (COX) enzyme activity and due neither to the downregulation of COX expression nor the inhibition of arachidonic acid release from plasma membranes. In macrophage:natural killer (NK) cell co-culture, propofol dramatically increased interferon-gamma (IFN-γ) production, and the actions of propofol were mimicked by a selective COX-2 inhibitor, NS-398, as well as the selective EP4 receptor antagonist L-161,982, suggesting a role of PGE₂ suppression in the upregulation of IFN-γ production. Furthermore, in purified NK cell culture, PGE₂ directly suppressed the production of IFN-γ by activated NK cells, which was reversed by selective inhibition of EP4 activity. Taken together, our results show that, in macrophage:NK cell co-culture, propofol, through the suppression of macrophage PGE₂ production, upregulates NK cell IFN-γ production by alleviating EP4 receptor-mediated suppression of IFN-γ production. Propofol may potentially exert considerable influence on inflammation and immunity by suppressing PGE₂ synthesis.     

雷公藤红素对小鼠的免疫抑制作用及其对IL-6mRNA表达影响的研究

目的：研究雷公藤红素对小鼠的免疫抑制作用及对细胞因子IL-6mRNA表达的影响。方法：采用碳粒廓清、迟发型变态反应、血清溶血素测定和T淋巴细胞转化实验，观察雷公藤红素对小鼠免疫功能的影响；运用RT—PCR半定量法研究雷公藤红素对小鼠肝脏IL-6mRNA表达影响。结果：雷公藤红素能抑制小鼠血清溶血素水平（400μg／kg），且与剂量呈依赖关系；小鼠耳廓肿胀度研究表明，雷公藤红素能使迟发型变态反应程度减轻（400μg／kg）；雷公藤红素剂量在0．25μg／mL时，可以明显抑制植物血凝素（PHA）诱导的细胞增殖；雷公藤红素800μg／kg能对抗CCl4引起的急性肝损伤小鼠肝脏IL-6mRNA含量的升高。结论：雷公藤红素在一定程度上能抑制小鼠的免疫功能，能抑制炎症细胞因子IL-6基因的过度表达．