激活素A对小鼠巨噬细胞RAW264.7吞噬活性的促进作用

目的探讨激活素A对巨噬细胞吞噬活性的促进作用及其机制。方法分别通过中性红试验、鸡红细胞法和流式细胞术,检测激活素A对巨噬细胞系RAW264.7细胞的吞饮活性、吞噬活性以及对MHCⅠ、Ⅱ类分子和CD68表达的影响。结果激活素A可明显促进RAW264.7细胞的吞饮及吞噬活性,对MHCI、II类分子表达没有影响,但可明显上调巨噬细胞表面分子CD68的表达。结论激活素A可促进巨噬细胞系RAW264.7细胞吞噬活性,这与其促进巨噬细胞成熟有关。     

激活素A抑制脂多糖活化巨噬细胞的作用机制

目的探讨激活素A(Activin A)抑制脂多糖(Lipopolysaccharides,LPS)活化巨噬细胞的作用机制。方法取小鼠巨噬细胞系RAW264.7细胞,分别添加Activin A(5 ng/ml)、LPS(1μg/ml)和Activin A(5 ng/ml)+LPS(1μg/ml),同时设以含单纯2.5%胎牛血清的DMEM培养液培养的细胞作为对照孔,培养24 h后,采用还原酶法检测细胞分泌一氧化氮(Nitric oxide,NO)的水平,流式细胞术分析TLR2和TLR4蛋白的表达水平,RT-PCR分析细胞ActRⅡA和ActRⅡB基因mRNA的转录水平。结果 Activin A和LPS单独作用均促进RAW264.7细胞分泌NO,但二者联合使用时,Activin A可抑制LPS刺激RAW264.7细胞的NO分泌;Activin A能抑制LPS上调RAW264.7细胞TLR4蛋白的表达,但对TLR2蛋白的表达无影响;LPS可促进RAW264.7细胞ActRⅡA基因mRNA的转录水平,但对ActRⅡB基因mRNA的转录水平无影响。结论 Activin A通过调控TLR4途径抑制LPS的作用,LPS可能通过促进ActRⅡA的表达进一步增强Activin A的负反馈调节作用。     

81种药用植物提取物影响小鼠巨噬细胞RAW264.7活化的研究

目的通过对81种药用植物提取物影响巨噬细胞活化的研究,获得相关活性数据,为后续研究开发和利用提供试验数据和物质基础。方法将提取物样品作用于RAW264.7细胞一定时间后,用ELISA法测定细胞分泌的TNF-α,以判断样品对细胞是否有活化作用;将LPS和81种提取物样品作用于RAW264.7细胞一定时间后,用ELISA法测定细胞分泌的TNF-α,以判断样品是否对LPS诱导的细胞活化有抑制作用。结果对81种药用植物提取物的研究结果表明,有34种植物提取物样品能够使RAW264.7细胞TNF-α表达上调,使其增加TNF-α的分泌;有2种植物提取物样品能够使LPS诱导的RAW264.7细胞TNF-α表达下调,使其减少TNF-α的分泌。结论通过对81种药用植物提取物的筛选研究表明,既有对巨噬细胞有活化作用的样品,也有能够抑制LPS诱导的巨噬细胞活化的样品,为进一步的研究,提供了相关活性数据和物质基础。     

hCAP-18/LL-37基因转染对RAW264.7细胞活化功能的影响

目的探讨抗菌肽hCAP-18/LL-37基因转染对巨噬细胞RAW264.7活化功能的影响。方法将重组质粒pcD-NA4/Myc-His-hCAP-18/LL-37瞬时转染RAW264.7细胞,MTT法检测细胞的增殖活性;中性红吞噬试验检测细胞的吞噬能力;RT-PCR法分析细胞活化相关分子CD80、CD86、TLR4及细胞因子IL-1β、TNF-αmRNA的转录。结果 hCAP-18/LL-37基因转染可促进经脂多糖(Lipopolysaccharide,LPS)处理的RAW264.7细胞的增殖活性与吞噬能力(P<0.05);可上调RAW264.7细胞CD80、CD86、TLR4、IL-1β、TNF-α基因mRNA的转录水平。结论 hCAP-18/LL-37基因转染可通过促进RAW264.7细胞增殖活性、吞噬能力及活化相关分子表达,调控巨噬细胞的活化功能。     

脂多糖诱导小鼠巨噬细胞系RAW264.7细胞的活化凋亡作用

目的探讨脂多糖(LPS)诱导小鼠巨噬细胞系RAW264.7细胞活化凋亡的作用。方法体外培养小鼠巨噬细胞系RAW264.7细胞,分别用0.5、1.0、2.5μg/mlLPS刺激RAW264.7细胞24h,一氧化氮(NO)试剂盒检测细胞培养上清中NO水平;用1.0μg/mlLPS分别刺激细胞3d和6d,台盼蓝拒染法检测细胞增殖情况;用1.0μg/mlLPS刺激细胞6d,流式细胞术分析细胞周期及细胞凋亡情况。结果经LPS刺激后24h,RAW264.7细胞培养上清中NO含量明显增加,且具有剂量依赖性;LPS刺激3d和6d后,细胞的增殖均受到抑制,且呈时间依赖性;LPS刺激6d时,细胞周期被阻滞在S期,并出现明显的凋亡。结论LPS具有诱导小鼠巨噬细胞系RAW264.7细胞活化凋亡的作用。     

补充生物活性肽QRPR对巨噬细胞RAW264.7抵御脂多糖刺激的作用

目的研究补充生物活性肽QRPR(Gln-Arg-Pro-AH)对巨噬细胞RAW264.7抵御脂多糖(lipopolysaccharides,LPS)刺激的作用。方法用不同浓度的LPS刺激RAW264.7细胞不同时间,ELISA法测定细胞培养上清中细胞因子白介素-6(interleukin-6,IL-6)及肿瘤坏死因子-α(tumor necrosis factor-alpha,TNF-α)的浓度,确定LPS刺激RAW264.7细胞的最适浓度和时间,建立RAW264.7细胞抵御LPS刺激模型。采用ELISA法测定QRPR肽对RAW264.7细胞抵御LPS刺激时IL-6和TNF-α表达量的影响。MTS法检测QRPR肽对RAW264.7细胞的毒性作用。结果100 ng/m L LPS诱导16 h为刺激RAW264.7细胞验证QRPR肽调节作用的最佳浓度和时间。QRPR肽可以抑制RAW264.7细胞受LPS刺激后IL-6和TNF-α的产生,QRPR肽浓度为250μmol/L时,其降低LPS刺激产生IL-6和TNF-α的能力最强。QRPR肽本身对RAW264.7细胞的生长既无促进作用,也无毒性和抑制作用。结论补充活性肽QRPR对巨噬细胞RAW264.7抵御LPS刺激具有积极的调节作用。     

凋亡细胞对巨噬细胞中白细胞介素-27表达的影响

目的探讨凋亡细胞对巨噬细胞中白细胞介素-27(Interleukin-27,IL-27)表达的影响。方法分别将小鼠巨噬细胞系RAW264.7(RAW细胞)和小鼠腹腔巨噬细胞分为6组:空白对照组、LPS刺激组、凋亡细胞刺激组、LPS+凋亡细胞刺激组、IFNγ+LPS刺激组及IFNγ+LPS+凋亡细胞刺激组。用IL-27 p28启动子荧光素酶报告基因瞬时转染RAW细胞,检测各组细胞中IL-27 p28启动子荧光素酶活性;RT-PCR法检测各组RAW细胞中IL-27 p28基因mRNA的转录水平,实时定量PCR法检测各组小鼠腹腔巨噬细胞中IL-27 p28基因mRNA的转录水平;Western blot法检测各组小鼠腹腔巨噬细胞中IL-27的表达水平。结果瞬时转染的RAW细胞中,IFNγ+LPS刺激组中IL-27 p28启动子荧光素酶活性明显高于空白对照组及IFNγ+LPS+凋亡细胞刺激组(P<0.05);RAW细胞与腹腔巨噬细胞中,LPS刺激组和IFNγ+LPS刺激组中IL-27 p28基因mRNA的转录水平明显高于空白对照组、LPS+凋亡细胞刺激组和IFNγ+LPS+凋亡细胞刺激组(P<0.05);LPS刺激组和IFNγ+LPS刺激组细胞中IL-27的表达水平明显高于LPS+凋亡细胞刺激组和IFNγ+LPS+凋亡细胞刺激组。结论巨噬细胞在摄取凋亡细胞后,IL-27 p28亚基的表达水平下降,从而导致IL-27的表达水平下降,为进一步研究其机制及临床应用奠定了理论基础。     

激活素A对L929细胞活性的调节作用

目的探讨激活素A对小鼠纤维母细胞L929活性的调节作用。方法用不同剂量的激活素A刺激L929细胞,应用还原酶法分析细胞分泌一氧化氮(NO)的水平,RT-PCR法检测细胞诱导型一氧化氮合成酶(iNOS)、纤维连接蛋白(FN)和金属蛋白酶组织抑制物(TIMP)mRNA的表达,应用中性红检测细胞的吞饮活性,MTT法检测细胞的增殖活性。结果L929细胞经激活素A刺激后,与对照组细胞比较,分泌NO的水平明显升高,iNOS mRNA及FN mRNA的表达水平也升高,而TIMP mRNA的表达水平无明显改变。激活素A可以促进L929细胞的吞饮活性,但对L929细胞的增殖活性无影响。结论激活素A具有促进L929细胞分泌炎性介质和形成细胞外基质的作用,这可能是其促进炎症发展、诱导组织纤维化的原因。     

绿豆肽对RAW264.7巨噬细胞的免疫调节作用

目的探讨绿豆肽对RAW264. 7巨噬细胞的免疫调节作用。方法在体外培养的RAW264. 7巨噬细胞中,分别加入10、100、200和400μg/mL的绿豆肽,检测RAW264. 7巨噬细胞的增殖能力、吞噬能力、SOD酶活力、NO含量和细胞因子分泌量,同时检测绿豆肽对经脂多糖(lipo-polysaccharide,LPS)诱导的RAW264. 7巨噬细胞中细胞因子分泌和LC3、p62蛋白表达水平的影响。结果与空白对照组比较,不同浓度绿豆肽组RAW264. 7巨噬细胞的增殖率及吞噬率显著提高(P 0. 05),400和200μg/mL组的SOD酶活力、NO含量及分泌TNF-α、IL-1β、IL-6水平均显著升高(P 0. 05)。各浓度绿豆肽均可显著抑制LPS诱导RAW264. 7巨噬细胞的TNF-α、IL-1β和IL-6分泌量(P 0. 05),浓度为400μg/mL时,上述细胞因子的分泌量与空白对照组差异无统计学意义(P 0. 05)。不同浓度绿豆肽均可降低LPS诱导RAW264. 7巨噬细胞胞内LC3的含量,上调p62蛋白的表达量。结论绿豆肽可激活巨噬细胞、增加自身代谢酶活力、释放细胞因子,通过抗炎作用及抑制细胞自噬,从而提高宿主细胞的免疫功能。     

对羟基苯乙酮的舒缓和控油功效研究

体外细胞方法评价对羟基苯乙酮的舒缓功效和控油功效,为其在化妆品中的应用提供新的功效依据。研究采用LPS诱导小鼠巨噬细胞RAW264.7株和睾酮诱导的皮脂腺细胞SZ95株,测定对羟基苯乙酮对一氧化氮（NO）、TNF-α、IL-6和油脂合成的抑制作用。结果显示,对羟基苯乙酮可显著抑制LPS诱导的巨噬细胞NO、TNF-α和IL-6含量（p<0.01）,0.05 mg/mL的对羟基苯乙酮对油脂合成的抑制率为17.64%(p<0.001)。研究表明对羟基苯乙酮可降低细胞的炎症反应,抑制油脂的分泌,具有一定的舒缓和控油效果。     

Escherichia coli Maltose-Binding Protein Induces M1 Polarity of RAW264.7 Macrophage Cells via a TLR2- and TLR4-Dependent Manner

Maltose-binding protein (MBP) is a critical player of the maltose/maltodextrin transport system in Escherichia coli. Our previous studies have revealed that MBP nonspecifically induces T helper type 1 (Th1) cell activation and activates peritoneal macrophages obtained from mouse. In the present study, we reported a direct stimulatory effect of MBP on RAW264.7 cells, a murine macrophage cell line. When stimulated with MBP, the production of nitric oxide (NO), IL-1β, IL-6 and IL-12p70, and the expressions of CD80, MHC class II and inducible nitric oxide synthase (iNOS) were all increased in RAW264.7 cells, indicating the activation and polarization of RAW264.7 cells into M1 macrophages induced by MBP. Further study showed that MBP stimulation upregulated the expression of TLR2 and TLR4 on RAW264.7 cells, which was accompanied by subsequent phosphorylation of IκB-α and p38 MAPK. Pretreatment with anti-TLR2 or anti-TLR4 antibodies largely inhibited the phosphorylation of IκB-α and p38 MAPK, and greatly reduced MBP-induced NO and IL-12p70 production, suggesting that the MBP-induced macrophage activation and polarization were mediated by TLR2 and TLR4 signaling pathways. The observed results were independent of lipopolysaccharide contamination. Our study provides a new insight into a mechanism by which MBP enhances immune responses and warrants the potential application of MBP as an immune adjuvant in immune therapies.     

激活素A对体外培养小鼠胎鼠大脑皮层神经元存活的促进作用

目的研究激活素A(Activin A)对体外培养小鼠胎鼠大脑皮层神经元存活的促进作用。方法原代培养孕期17d小鼠胎鼠脑神经细胞,免疫细胞化学染色观察激活素受体(ActRIIA)在神经细胞中的表达;将原代培养神经细胞分为阴性对照组(5%胎牛血清-DMEM/F12培养基)、阳性对照组(4ng/ml神经生长因子)和激活素A(5ng/ml)组,分别于培养第1、3、5、7和9天,采用台酚蓝染色法检测神经元存活情况。结果培养的小鼠胎鼠脑神经细胞可表达ActRIIA;阴性对照组存活神经元呈时间依赖性减少,在培养第9天已检测不到存活的神经元;而阳性对照组和激活素A组在培养第9天仍有部分神经元存活。结论激活素A具有维持小鼠胎鼠大脑皮层神经元长期存活的作用。     

激活素A对小鼠腹腔巨噬细胞分泌细胞因子的影响

目的探讨激活素A对小鼠腹腔巨噬细胞分泌细胞因子的影响。方法分离小鼠腹腔巨噬细胞,将其分为激活素A处理组和对照组,瑞氏-吉姆萨染色观察小鼠腹腔巨噬细胞形态学变化;流式细胞术分析小鼠腹腔巨噬细胞表面分子CD68的表达;ELISA法检测小鼠腹腔巨噬细胞分泌IL-10及TNFα的水平;Griess法检测小鼠腹腔巨噬细胞分泌NO的水平。结果经激活素A刺激后,显微镜下可见呈不规则、多边型的活化巨噬细胞增多,细胞表达巨噬细胞成熟标志CD68增加,Ⅱ型巨噬细胞(M2)产生的细胞因子IL-10及NO分泌水平升高,而Ⅰ型巨噬细胞(M1)产生的细胞因子TNFα水平无变化。结论激活素A可能主要促进小鼠Ⅱ型巨噬细胞分泌细胞因子。     

EPA and DHA Exposure Alters the Inflammatory Response but not the Surface Expression of Toll‐like Receptor 4 in Macrophages

Dietary intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and their respective enrichment in cell membranes have been negatively associated with atherosclerotic lesion development. This effect may be mediated, in part, by dampened inflammatory response of macrophages triggered by toll‐like receptor 4 (TLR4) activation. This study investigated the influence of membrane fatty acid profile on TLR4‐mediated inflammation in RAW 264.7 macrophages. Cells pretreated with myristic acid (MA), EPA, DHA or vehicle control for 24 h were stimulated with ultra‐pure LPS, a specific TLR4 agonist, for 6 or 24 h, corresponding to early and late stages of TNFα and IL‐6 protein induction. Treatment significantly increased cell membrane MA, EPA, and DHA by 4.5‐, 20.6‐, and 8.9‐fold, respectively. MA significantly increased IL‐6 secretion 6 h post‐exposure to the fatty acid, but did not change TNFα secretion in response to any other treatment condition. EPA and DHA significantly reduced TNFα secretion by 36 and 41 %, respectively, in cells stimulated for 24 h but not 6 h. In contrast, EPA and DHA significantly reduced IL‐6 secretion at both 6 h (67 and 72 %, respectively) and 24 h (69 and 72 %, respectively). MA or DHA treatment had no significant effect compared to vehicle on factors influencing cellular LPS recognition, including LPS‐cell association, and cell surface expression of TLR4, TLR4‐MD2 complex, and CD14. These data suggest that membrane fatty acid profiles influence the TLR4‐mediated inflammatory response in macrophages, via mechanisms that occur downstream of TLR4 receptor activation.     

Anti-Inflammatory Effect of Auranofin on Palmitic Acid and LPS-Induced Inflammatory Response by Modulating TLR4 and NOX4-Mediated NF-κB Signaling Pathway in RAW264.7 Macrophages

Chronic inflammation, which is promoted by the production and secretion of inflammatory mediators and cytokines in activated macrophages, is responsible for the development of many diseases. Auranofin is a Food and Drug Administration-approved gold-based compound for the treatment of rheumatoid arthritis, and evidence suggests that auranofin could be a potential therapeutic agent for inflammation. In this study, to demonstrate the inhibitory effect of auranofin on chronic inflammation, a saturated fatty acid, palmitic acid (PA), and a low concentration of lipopolysaccharide (LPS) were used to activate RAW264.7 macrophages. The results show that PA amplified LPS signals to produce nitric oxide (NO) and various cytokines. However, auranofin significantly inhibited the levels of NO, monocyte chemoattractant protein-1, and pro-inflammatory cytokines, such as interleukin (IL)-1β, tumor necrosis factor-α, and IL-6, which had been increased by co-treatment with PA and LPS. Moreover, the expression of inducible NO synthase, IL-1β, and IL-6 mRNA and protein levels increased by PA and LPS were reduced by auranofin. In particular, the upregulation of NADPH oxidase (NOX) 4 and the translocation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) induced by PA and LPS were suppressed by auranofin. The binding between the toll-like receptor (TLR) 4 and auranofin was also predicted, and the release of NO and cytokines was reduced more by simultaneous treatment with auranofin and TLR4 inhibitor than by auranofin alone. In conclusion, all these findings suggested that auranofin had anti-inflammatory effects in PA and LPS-induced macrophages by interacting with TLR4 and downregulating the NOX4-mediated NF-κB signaling pathway.