Inhibition of lipopolysaccharide-induced inducible nitric oxide (iNOS) mRNA expression and nitric oxide production by higenamine in murine peritoneal macrophages

Nitric oxide synthesized by inducible nitric oxide synthase (iNOS) has been implicated as a mediator of inflammation in rheumatic and autoimmune diseases. The effects of higenamine, a tetrahydroisoquinoline compound, on induction of NOS by bacterial lipopolysaccharide (LPS) were examined in murine peritoneal macrophages. LPS-induced nitrite/nitrate production was markedly inhibited by higenamine which at 0.01 mM, decreased nitrite/nitrate levels by 48.7+/-4.4%. This was comparable to the inhibition of LPS-induced nitrite/nitrate production by tetrandrin (49.51+/-2.02%) at the same concentration. Northern and Western blot analysis of iNOS expression demonstrated that iNOS expression was significantly attenuated following co-incubation of peritoneal macrophages with LPS (10 microg/ml; 18 hrs) and higenamine (0.001, 0.01 mM; 18 hrs). These results suggest that higenamine can inhibit LPS-induced expression of iNOS mRNA in murine peritoneal macrophages. The clinical implications of these findings remain to be established.     

香菇多糖对巨噬细胞一氧化氮和一氧化氮合酶活性的影响

目的研究香菇多糖(LTN)诱导巨噬细胞的一氧化氮(NO)生成和一氧化氮合酶(iNOS)的活性,探讨LTN的免疫调节作用机理.方法采用Griess反应和荧光法测定不同剂量的LTN作用小鼠腹腔巨噬细胞后NO的生成量和iNOS活性.观察mRNA转录抑制剂、蛋白质合成抑制剂和iNOS抑制剂对巨噬细胞NO的生成和iNOS活性的影响.结果LTN能使小鼠腹腔巨噬细胞NO生成增加,iNOS活性增高,并呈作用剂量依赖关系.3种抑制剂均能抑制LTN诱导的小鼠腹腔巨噬细胞N0的生成和iNOS活性.结论LTN能刺激小鼠腹腔巨噬细胞提高iNOS活性和NO的生成.提示LTN的免疫调节作用机制可能与LTN刺激巨噬细胞NO生成有关.     

酵母多糖对小鼠腹腔巨噬细胞产生一氧化氮和白细胞介素-1的影响

目的探讨酵母多糖对小鼠腹腔巨噬细胞产生一氧化氮 (NO)和白细胞介素 1(IL 1)的影响。方法将不同剂量的酵母多糖加入体外培养的小鼠腹腔巨噬细胞中 ,取细胞培养上清液根据Griess反应检测NO-2 的量 ,间接反映巨噬细胞产生NO的生成量 ,并用溴化四唑蓝 (MTT)比色法检测上清液中IL 1的生成量。结果酵母多糖可明显促进小鼠腹腔巨细胞产生NO和IL 1,NO的生成量呈现剂量依赖关系。结论酵母多糖可诱导小鼠腹腔巨噬细胞产生NO和IL 1,可能是酵母多糖调节机体免疫功能、杀伤病原微生物和抗肿瘤的重要途径     

灵芝多糖肽对小鼠腹腔巨噬细胞一氧化氮产生的影响

目的　研究灵芝多糖肽 (GLPP)对小鼠腹腔巨噬细胞一氧化氮产生的影响并探讨其作用机制。方法　以Griess法 ,观察GLPP对LPS诱导小鼠腹腔巨噬细胞一氧化氮(NO)产生的影响 ;以免疫组化法检测诱导型一氧化氮合成酶 (iNOS)的表达 ,观察GLPP对iNOS的影响。结果　GLPP(2 5～ 2 0 0mg·kg-1)灌胃给药 5d或体外给药 (3 12 5～ 2 0 0mg·L-1)均可促进巨噬细胞NO释放 ,但对LPS刺激NO的释放影响不大 ;GLPP(10 0mg·kg-1)灌胃给药 5d或体外给药 (10mg·L-1)均可使巨噬细胞iNOS含量增加。结论　GLPP可增加小鼠腹腔巨噬细胞NO产生 ,其机制可能与其促进巨噬细胞iNOS合成有关。     

雷公藤多甙抑制小鼠腹腔巨噬细胞产生一氧化氮

雷公藤多甙（ｐｏｌｙｇｌｙｃｏｓｉｄｅｏｆＴｒｉｐｔｅｒｙｇｉｕｍｗｉｌｆｏｒｄｉＨｏｏｋ．ｆ．,ＴＷＰ）临床广泛用于治疗类风湿性关节炎等多种自身免疫性疾病,既可抑制细胞免疫又可抑制体液免疫［１］．但其在免疫抑制过程中对一氧化氮合酶（ＮＯＳ）的影响却...     

Inhibitory effects of Zataria multiflora essential oil and its main components on nitric oxide and hydrogen peroxide production in lipopolysaccharide-stimulated macrophages

Objectives Zataria multiflora is an aromatic plant that is used in flavouring and preserving foods and also used as an antispasmodic, anaesthetic and antinociceptive agent. In this study, the effects of Z. multiflora essential oil on nitric oxide (NO) and hydrogen peroxide (H₂O₂) production in lipopolysaccharide (LPS)‐stimulated macrophages was investigated. Methods Z. multiflora essential oil was extracted by water‐distillation, analysed by GC‐MS and then the effect of the essential oil on NO and H₂O₂ production was investigated. Key findings Carvacrol (52%), thymol (16%) and p‐cymene (10%) were the main components of the oil. The IC50 (concentration providing 50% inhibition) for reactive oxygen scavenging was estimated to be 5.7, 3 and 4.2 µg/ml for the essential oil, thymol and carvacrol, respectively, while the corresponding IC50 values for reactive nitrogen scavenging were estimated to be 8.6, 4.7 and 6.6 µg/ml. Z. multiflora essential oil, thymol, and carvacrol significantly reduced NO and H₂O₂ production as well as NO synthase and NADH oxidase activity in LPS‐stimulated murine macrophages while p‐cymene did not show any antioxidant activity. Conclusions Z. multiflora essential oil has the potential to be used in the therapy of oxidative damage.     

库拉索芦荟多糖对小鼠腹腔巨噬细胞一氧化氮生成的影响

目的研究库拉索芦荟多糖对小鼠腹腔巨噬细胞一氧化氮(NO)生成的影响。方法用G riess法测定巨噬细胞一氧化氮的生成量。结果库拉索芦荟多糖在25~400μg/mL浓度范围可显著促进正常巨噬细胞的NO生成,在50~400μg/mL浓度范围可抑制LPS激活的巨噬细胞的NO生成。结论库拉索芦荟多糖对小鼠腹腔巨噬细胞一氧化氮的生成具有双向调节作用。     

YC-1 potentiates cAMP-induced CREB activation and nitric oxide production in alveolar macrophages

Alveolar macrophages play significant roles in the pathogenesis of several inflammatory lung diseases. Increases in exhaled nitric oxide (NO) are well documented to reflect disease severity in the airway. In this study, we investigated the effect of 3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole (YC-1), a known activator of soluble guanylyl cyclase, on prostaglandin (PG)E₁ (a stable PGE₂ analogue) and forskolin (a adenylate cyclase activator) induced NO production and inducible NO synthase (iNOS) expression in rat alveolar macrophages (NR8383). YC-1 did not directly cause NO production or iNOS expression, but drastically potentiated PGE₁- or forskolin-induced NO production and iNOS expression in NR8383 alveolar macrophages. Combination treatment with YC-1 and PGE₁ significantly increased phosphorylation of the cAMP response element-binding protein (CREB), but not nuclear factor (NF)-κB activation. The combined effect on NO production, iNOS expression, and CREB phosphorylation was reversed by a protein kinase (PK)A inhibitor (H89), suggesting that the potentiating functions were mediated through a cAMP/PKA signaling pathway. Consistent with this, cAMP analogues, but not the cGMP analogue, caused NO release, iNOS expression, and CREB activation. YC-1 treatment induced an increase in PGE₁-induced cAMP formation, which occurred through the inhibition of cAMP-specific phosphodiesterase (PDE) activity. Furthermore, the combination of rolipram (an inhibitor of PDE4), but not milronone (an inhibitor of PDE3), and PGE₁ also triggered NO production and iNOS expression. In summary, YC-1 potentiates PGE₁-induced NO production and iNOS expression in alveolar macrophages through inhibition of cAMP PDE activity and activation of the cAMP/PKA/CREB signaling pathway.     

花色素苷诱导小鼠巨噬细胞一氧化氮生成及其机制

目的研究花色素苷对小鼠腹腔巨噬细胞一氧化氮(NO)合成的诱导作用及其机制。方法用CCK-8试剂检测花色素苷对小鼠脾细胞增殖的影响;硝酸盐还原酶法检测小鼠腹腔巨噬细胞NO含量;荧光法检测一氧化氮合酶(NOS)活性;RT-PCR检测iNOS mRNA的表达。结果花色素苷可促进小鼠脾细胞增殖,诱导小鼠腹腔巨噬细胞合成NO,提高NOS活性,其中矢车菊素-3-葡萄糖苷能够诱导iNOS mRNA的表达。结论花色素苷能够促进脾细胞的增殖,诱导小鼠腹腔巨噬细胞合成NO,使巨噬细胞激活,具有一定的免疫调节活性。     

普伐他汀对人内皮祖细胞一氧化氮合成的影响

目的观察普伐他汀对人内皮祖细胞（EPCs）一氧化氮（NO）合成的影响。方法密度梯度离心法获取外周血单个核细胞,培养7d后,收集贴壁细胞并分别加入普伐他汀,10μmol/L及100μmol/L干预48h,免疫组化、荧光显微镜和流式细胞仪鉴定EPC,用RT-PCR方法测定对细胞内皮型一氧化氮合酶（eNOS）mRNA表达的影响,并用硝酸还原酶法测定培养液中一氧化氮（NO）的水平。结果普伐他汀组的人内皮祖细胞eNOS mRNA的表达、NO的合成明显增加。结论普伐他汀可增加人内皮祖细胞eNOS mRNA的表达和NO的合成     

Spantide抑制甲醛炎性痛大鼠脊髓一氧化氮合酶表达和一氧化氮含量的增加(英文)

目的　观察鞘内注射P物质 (SP)拮抗剂spantide { [D Arg1,D Trp7,9,Leu11] substanceP}对炎性痛大鼠L5节段脊髓后角一氧化氮合酶 (NOS)表达和腰膨大一氧化氮 (NO)含量的影响 ,以探讨痛及痛过敏时脊髓NOS表达和NO生成增多的机制。方法　大鼠右后掌足底皮下注射 5 %甲醛 0 .2mL诱发炎性痛及痛过敏 ,NADPH d组化法观察脊髓后角NOS表达的变化 ,硝酸还原酶法测定NO含量的变化。结果　皮下注射甲醛 2 4h后 ,双侧L5节段脊髓后角NOS表达及腰膨大部位NO生成明显增加 ;注射甲醛前 5min鞘内注射spantide (5 μg ,10 μL) ,则明显抑制甲醛所致的NOS表达及NO生成增加。结论　初级传入末梢释放的SP在甲醛炎性痛及痛过敏时脊髓NOS表达及NO生成增多中发挥作用     

Evidences for iNOS expression and nitric oxide production in the human macrophages

Nitric oxide (NO) is a pleiotropic mediator of numerous biological processes, including smooth muscle relaxation, neurotransmission and defence against pathogens. In addition, NO is involved in the pathogenesis and control of inflammation, tumors, autoimmunity, and infectious and chronic degenerative diseases. NO, a highly reactive radical, is produced from L-arginine and oxygen by the enzyme NO synthase (NOS). Three NOS isoforms have been identified: two distinct NOS isoforms are constitutively expressed in cells, whereas a third isoform, inducible NOS (iNOS), is transcribed in response to specific stimuli. In particular, iNOS is responsible for the discontinuous synthesis of high amounts of NO and was originally characterized in murine macrophages after exposure to cytokines and/or microbial products. A wide range of microorganisms is sensibly inhibited in its development by NO, like fungi, bacteria, protozoa and viruses. Although NO production and its antimicrobial effect appear well established in rodent macrophages, the existence of L-arginine pathway in human mononuclear phagocytes has long been disputed. Recently, evidences showing the iNOS activity and NO production in other animal models, including humans, are now emerging, even if the NO induction has been more difficult to demonstrate. The present observations provide evidence for the occurrence of iNOS protein expression and NO production in human macrophages cultured in vitro.     

S-亚硝基-N-乙酰-DL-青霉安对巨噬细胞诱导型一氧化氮合酶的影响

目的 观察S-亚硝基-N-乙酰-DL-青霉胺（SNAP）对RAW 264.7诱导型一氧化氮合酶（iNOS）表达的影响,探讨NO在动脉粥样硬化（炎症）过程中的作用.方法 以RAW 264.7巨噬细胞为研究对象,分为空白对照组、SNAP组,采用不同浓度（30、100、300、400、500μmol/L）的SNAP对巨噬细胞进行干预24 h,应用RT-PCR法检测RAW 264.7巨噬细胞iNOS mRNA的表达,采用Western blotting技术检测iNOS蛋白的表达.结果 与空白对照组比较,不同浓度SNAP（30、100、300、400、500 μmol/L）组iNOS mRNA的表达比空白对照组均明显降低（P＜0.05）,不同浓度SNAP（30、100、300 μmol/L）组iNOS蛋白表达明显低于空白对照组（P＜0.05）.结论 NO可以抑制巨噬细胞自身iNOS mRNA基因转录,降低iNOS的合成而发挥负反馈作用.     

Inhibition of lipopolysaccharide-induced nitric oxide production by flavonoids in RAW264.7 macrophages involves heme oxygenase-1

The role of heme oxygenase-1 (HO-1) played in the inhibitory mechanism of flavonoids in lipopolysaccharide (LPS)-induced responses remained unresolved. In the present study, flavonoids, including 3-OH flavone, baicalein, kaempferol, and quercetin, induced HO-1 gene expression at the protein and mRNA levels in the presence or absence of LPS in RAW264.7 macrophages. This effect was associated with suppression of LPS-induced nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) protein expression. Hemin induced HO-1 protein expression and this was associated with the suppression of LPS-induced NO production and iNOS protein expression in a dose-dependent manner. In addition, an increase in bilirubin production was found in flavonoid- and hemin-treated cells. Hemin, at the doses of 10, 20, and 50 microM, dose-dependently stimulated the flavonoid (50 microM)-induced HO-1 protein expression, and enhanced their inhibitory effects on LPS-induced NO production and iNOS protein expression. Pretreatment of the HO-1 inhibitor, tin protoporphyrin (10 microM), attenuated the inhibitory activities of the indicated flavonoids on LPS-induced NO production. Morphologic analysis showed that 3-OH flavone, baicalein, kaempferol, quercetin, hemin, and tin protoporphyrin did not cause any change in cell viability in the presence or absence of LPS. In contrast, only 3-OH flavone showed a significant inhibition of cell growth using the MTT assay. Transfection of an HO-1 vector in macrophages (HO-1/RAW264.7) resulted in a 3-fold increase in HO-1 protein compared with that the parental RAW264.7 cells. NO production mediated by LPS in HO-1 over-expressed RAW264.7 cells (HO-1/RAW264.7) was significant less than that in parental RAW264.7 cells. 3-OH Flavone, baicalein, kaempferol, and quercetin showed a more significant inhibition on LPS-induced NO production in HO-1/RAW264.7 cells than in parental RAW264.7 cells. These results provide evidence on the role of HO-1 in the inhibition of LPS-induced NO production by flavonoids. A combination of HO-1 inducers (i.e. hemin) and flavonoids might be an effective strategy for the suppression of LPS-induced NO production.     

Role of nitric oxide produced by constitutive and inducible nitric oxide synthases in the mouse gastric fundus

In the present study, the role of nitric oxide (NO) produced by constitutive and inducible nitric oxide synthases (cNOS and iNOS, resepctively) on the contraction and relaxation of fundus in normal and lipopolysaccharide (LPS)-treated mice was examined. A whole fundic ring isolated from mice pretreated with reserpine was mounted in an organ bath containing Krebs' solution with 0.001 mmol/L atropine. Rings were contracted initially by 5-hydroxytryptamine (5-HT; 0.03 mmol/L) before relaxation was induced using ATP (0.03 mmol/L), ADP (0.03 mmol/L), pentoxifylline (0.002 mmol/L), electrical field stimulation (EFS; 50 V, 1 msec, 50 Hz, 3 min) and L-arginine (0.05 mmol/L). All drugs and EFS induced significant relaxation of isolated rings. The relaxations induced were significantly inhibited by N(G)-nitro-L-arginine methyl ester (L-NAME; 1.0 mmol/L). However, the iNOS inhibitors L-N(6)-(1-iminoethyl) lysine hydrochloride (L-NIL; 1.0 mmol/L) and amino guanidine (AMG; 1.0 mmol/L) had no significant effect on tissue relaxation. Then, the relaxant effects of 0.03 mmol/L ATP were tested on precontracted isolated fundic rings taken from 10 mg/kg LPS-treated animals. The non-selective NOS inhibitor L-NAME (10 mg/kg), the iNOS inhibitors L-NIL (3 mg/kg) and AMG (20 mg/kg) and betamethasone (0.1 mg/kg) were used to examine the role of NO produced by iNOS in the relaxation responses. It was found that the level of contraction induced by 0.03 mmol/L 5-HT in rings isolated from LPS-treated animals was significantly (P < 0.5) less than that in rings from untreated mice. However, precontracted tissues from LPS-treated mice were significantly relaxed by ATP and the relaxation response to ATP was significantly inhibited by L-NIL, ANG and betamethasone, but not by L-NAME. We suggest that, in LPS-treated mice, the production of NO from iNOS produces a reduction in the contractile response, as well as a decrease in NO formation by cNOS, resulting in changes to smooth muscle cell function.     

Inhibitory effect of CDP, a polysaccharide extracted from the mushroom Collybia dryophila, on nitric oxide synthase expression and nitric oxide production in macrophages

The effect of Collybia dryophila polysaccharide (CDP), a (1-->3), (1-->4)-beta-D-glucan extracted from the mushroom C. dryophila, was evaluated on nitric oxide (NO) production induced by lipopolysaccharide (LPS) and gamma interferon (IFNgamma) or by LPS alone in RAW 264.7 cells. CDP significantly inhibited NO production in a dose-dependent manner without affecting cell viability. The inhibition of NO by CDP was consistent with decreases in both inducible nitric oxide synthase (iNOS) protein and mRNA expression suggesting that CDP exerts its effect by inhibiting iNOS gene expression. In addition, CDP at concentrations of 400 and 800 microg/ml was shown to significantly increase prostaglandin E2 (PGE2) production in LPS- and IFNgamma-induced macrophages when compared to the control.     

Inhibition of nitric oxide synthase by antisense techniques: investigations of the roles of NO produced by murine macrophages

1. An antisense approach to block nitric oxide (NO) synthesis was developed, complementing the widely used chemical inhibitors and overcoming problems associated with their use in studying the roles of NO.
2. Murine macrophage cell lines (J774.2) were generated expressing a 500 bp sequence from inducible NO synthase (iNOS) in either the antisense or sense orientation, driven by the SV40 promoter/enhancer region.
3. Messenger RNA derived from the transfected sequences was detected by a specific cDNA probe. Cells expressing sense and antisense iNOS RNA were characterized further.
4. The antisense lines produced 22–97% less NO than the sense lines on stimulation with lipopolysaccharide (LPS) in the range 1 ng ml⁻¹–10 μg ml⁻¹, as determined by nitrite production. One antisense line in particular, A10, expressed substantially less iNOS protein on LPS stimulation as determined by western blot analysis.
5. Adhesion of the antisense line, A10, to cytokine-stimulated murine endothelial cells (sEnd.1 line) was significantly higher than adhesion of the sense lines. There was a negative correlation between the amount of NO produced, as determined by nitrite accumulation, and the level of adhesion of the transfected lines. This indicates an anti-adhesive role of NO, produced by macrophages during the 15 min of the assay, in adhesion to endothelial cells.
6. This novel approach allowed the roles of NO in adhesion to be investigated with the substantial advantage that the contribution of NO produced rapidly by activated macrophages could be studied separately from that produced in a continuous manner by endothelial cells.
7. These lines, and the extension of this approach, will be of great use in dissecting the contributions of NO produced by different cell types to its many potential functions.