IL-24 is expressed by rat and human macrophages

Recently, a number of interleukin-10 (IL-10) homologues, among them IL-24 formerly known as melanocyte differentiation factor-7 (mda-7), has been described. Since IL-10 is released by macrophages and plays an important role in the resolution of inflammatory processes, we hypothesized that IL-24 might also be expressed in cells of the monocyte/macrophage lineage. We analyzed IL-24 expression on the mRNA and protein level in stimulated rat and human macrophages. In rat alveolar macrophages and NR8383 cells, IL-24 mRNA induction was observed following stimulation with LPS and IL-4 whereas TNF-alpha failed. Intracellular IL-24 protein was detected in unstimulated and IL-4 stimulated NR8383 cells. Also human blood monocytes showed a strong up-regulation of IL-24 mRNA following preparation which was enhanced by LPS and lowered by IL-10. Furthermore, infection of human monocytes with influenza A virus A/PR/8 caused an induction of IL-24 mRNA expression. In conclusion, our data show that IL-24 expression is induced in stimulated and infected rat and human macrophages, however, more insights into the functions of IL-24 are necessary to define its physiological relevance.     

Syk and paxillin are differentially phosphorylated following adhesion to the plastic substrate in rat alveolar macrophages.

Adhesion is associated with tyrosine phosphorylation in many types of cells. Although macrophages are known to adhere and phagocytose foreign particles, the signal transduction pathway of macrophages in response to adhesion to the foreign substrate has not been fully investigated. In the present study we investigated tyrosine-phosphorylated proteins and phosphorylation of paxillin in alveolar macrophages (AMs) following adhesion to a plastic substrate. Adhesion to a plastic dish resulted in tyrosine phosphorylation of a 68 000 MW protein, which was shown, by immunoprecipitation and immunoblotting in the present study, to be a rat Syk kinase. Treatment with erbstatin reduced both tyrosine phosphorylation of Syk and adherence of AMs, while treatment with cytochalasin B inhibited spreading of AMs but did not inhibit tyrosine phosphorylation of Syk. These results suggest that tyrosine phosphorylation of Syk plays an important role in adhesion of AMs to the plastic substrate, but not in AM spreading. Paxillin is known to be tyrosine phosphorylated following adhesion to the extracellular matrix in many types of cells. However, paxillin appeared to be serine/threonine phosphorylated rather than tyrosine phosphorylated following adhesion of AMs to the plastic substrate. Treatment with A23187 (a calcium ionophore), but not phorbol 12-myristate 13-acetate (PMA; a protein kinase C stimulator), induced tyrosine phosphorylation of Syk in non-adherent AMs. Treatment with either A23187 or PMA caused electromobility changes of paxillin that were mainly a result of serine/threonine phosphorylation. These results suggest that adhesion to the plastic substrate leads to two differently regulated events in AMs: tyrosine phosphorylation of Syk and serine/threonine phosphorylation of paxillin, both of which are probably mediated by an increase in intracellular calcium.     

Pneumocystis carinii induces an oxidative burst in alveolar macrophages.

There is evidence that alveolar macrophages (AM) play a role in the clearing of Pneumocystis carinii from the lungs. To investigate the mechanisms involved in this process, we studied in vitro the induction of an oxidative burst by P. carinii in a cell line of macrophages (NR8383) and AM from normal rats. P. carinii was added to macrophage monolayers (10(6) cells), and the H2O2 produced after 4 h of incubation was measured. Both NR8383 macrophages and normal rat AM produced H2O2 in response to P. carinii cysts and trophozoites isolated from dexamethasone-treated rats, although the amount of H2O2 induced in AM from normal rats was larger. NR8383 macrophages bound and phagocytized both P. carinii cysts and trophozoites and produced increasing amounts of H2O2 as a dose-related response to cysts and trophozoites. Opsonization of P. carinii with normal rat serum increased H2O2 production by both types of macrophages; this enhancement was decreased, but not abolished, when the serum was first depleted of complement by heat treatment. These findings demonstrate that NR8383 macrophages and normal rat AM produce an oxidative burst in response to P. carinii and that this response is enhanced by complement.     

miR-181a参与调控香烟提取物诱导的NR8383肺泡巨噬细胞自噬紊乱与促炎因子的生成

目的:探讨微小RNA-181a(miR-181a)对香烟提取物(CSE)诱导的NR8383大鼠肺泡巨噬细胞自噬紊乱与促炎因子生成的影响。方法:采用5%、10%和20%浓度的CSE刺激NR8383细胞,ELISA法检测肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)和IL-8的分泌,RT-qPCR检测miR-181a水平,Cyto-ID染色检测自噬体数量,Western blot法检测LC3-Ⅱ、beclin-1和p62的表达。在20%CSE条件下,采用自噬抑制剂3-甲基腺嘌呤(3-MA)或自噬激动剂雷帕霉素(Rapa)预处理细胞,ELISA检测TNF-α、IL-6和IL-8的分泌;进一步转染miR-181a mimic或miR-181a inhibitor后,分别采用ELISA和Western blot观察在20%CSE条件下,细胞TNF-α、IL-6和IL-8分泌及LC3-Ⅱ、beclin-1和p62表达的情况。结果:CSE浓度依赖性促进NR8383细胞促炎因子生成和自噬紊乱;3-MA促进CSE诱导的NR8383细胞促炎因子释放,而Rapa部分逆转CSE诱导的NR8383细胞促炎因子释放;miR-181a mimic显著抑制CSE诱导的NR8383细胞促炎因子生成,促进自噬,miR-181a inhibitor促进CSE诱导的NR8383细胞促炎因子生成,加剧自噬紊乱。结论:miR-181a调控CSE诱导的NR8383细胞促炎因子释放可能与其调控自噬紊乱有关。     

程序性细胞死亡因子4是替代活化巨噬细胞的新分子标志物

背景：程序性细胞死亡因子4的表达水平与经典活化的巨噬细胞的表型负相关,但是程序性细胞死亡因子4的表达水平与巨噬细胞替代活化的关系仍不明确。 目的：观察替代活化的巨噬细胞中程序性细胞死亡因子4的表达水平改变,及其对替代活化的影响。 方法：用白细胞介素4、地塞米松单独刺激或联合刺激诱导NR 8383 细胞的替代活化;采用qPCR检测巨噬细胞替代活化的分子标志物的表达水平,确定诱导巨噬细胞替代活化的最适条件;采用qPCR和Western blot 检测替代活化的巨噬细胞模型中程序性细胞死亡因子4表达的改变;分别用大鼠程序性细胞死亡因子4高表达质粒和程序性细胞死亡因子4干扰质粒转染NR 8383细胞株,采用荧光倒置显微镜观察转染的效率,并检测程序性细胞死亡因子4的表达水平;分别检测程序性细胞死亡因子4 高表达和程序性细胞死亡因子4敲低后 NR 8383 细胞株中巨噬细胞经典活化和替代活化的分子标志。 结果与结论：①白细胞介素4和地塞米松联合刺激比白细胞介素4或地塞米松单独刺激可更有效的诱导巨噬细胞的替代活化;10 μg/L白细胞介素4+50 nmol/ L 地塞米松刺激24 h可有效诱导巨噬细胞的替代活化。②在替代活化的巨噬细胞中程序性细胞死亡因子4的表达水平显著升高,是替代活化的分子标志。③程序性细胞死亡因子4高表达上调替代活化的分子标志的表达(P < 0.05);而敲低程序性细胞死亡因子4可下调 CD206的表达(P < 0.05),并显著上调经典活化的分子标志诱导型一氧化氮合酶的表达(P < 0.05)。结果表明程序性细胞死亡因子4上调是替代活化巨噬细胞的一个重要分子标志物。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

MicroRNA-132转染对脂多糖诱导的肺泡巨噬细胞炎症反应的作用

 目的:探讨转染微小RNA-132（miR-132）对肺泡巨噬细胞炎症反应的作用。方法: 将体外去致热源培养的大鼠肺泡巨噬细胞株NR8383分为空白对照组、阴性对照组和转染组,分别采用miR-132增敏剂、错义链和PBS作用。转染24 h后,CCK-8法检测细胞増殖;实时荧光定量PCR检测细胞中miR-132的表达;用脂多糖（LPS）作用细胞后,凝胶电泳迁移率实验（EMSA）检测细胞中NF-κB活性;Western blotting法检测细胞中肿瘤坏死因子α（TNF-α）和白细胞介素6（IL-6）的表达。结果: 与空白对照组和阴性对照组相比较,转染组细胞中miR-132的表达明显升高;转染组细胞増殖被明显抑制,与空白对照组相比较,差异有统计学意义（P<0.05）;LPS作用后,转染组NF-κB、TNF-α和IL-6表达量显著下降,与空白对照组和阴性对照组相比较,差异均有统计学意义（P<0.05）。结论: 转染miR-132可抑制NR8383细胞増殖,并抑制LPS诱导的NR8383细胞的炎症反应。     

香烟烟气提取物对NR8383细胞吞噬功能的影响

目的 探讨不同浓度香烟烟气提取物(CSE)对大鼠肺泡巨噬细胞(NR8383)吞噬功能的影响.方法 通过CCK-8法分析细胞比活力,Annexin-V FITC/PI双染法检测细胞凋亡以及CFSE荧光标记分析细胞的分裂增殖,来确定CSE对NR8383细胞的作用浓度和作用时间.收集经不同浓度CSE处理24 h的NR8383细胞,与FITC标记的大肠杆菌共同孵育2 h后,用流式细胞仪检测胞内荧光强度,分析CSE对细胞吞噬功能的影响.结果 NR8383细胞的吞噬功能随着CSE浓度的变化先增强后降低.单独用CSE处理NR8383细胞,在100μg/ml CSE作用下,巨噬细胞的吞噬功能与正常对照组相比提高0.5倍,此时的细胞比活力最高.在CSE和LPS共同作用下,CSE的浓度为100μg/ml时,NR8383细胞的吞噬功能提高到正常水平的3倍.而当CSE浓度达到200μg/ml时,NR8383细胞的吞噬功能受到损伤,细胞凋亡率为54.1%.结论 CSE可以影响NR8383细胞的吞噬功能,在较低浓度时可能激活巨噬细胞的吞噬功能,但较高浓度时可能对巨噬细胞的吞噬功能造成损伤,CSE可能具有激活巨噬细胞吞噬功能的潜能.

Abstract：

Objective To investigate the phagocytosis function of cigarette smoke extracts (CSE)on the NR8383 cells. Methods The concentration of CSE and the optimal time was defined by cell counting kit-8 assay, Annexin V/PI cell apoptosis assay and CFSE cell proliferation assay. The cell was gained after exposed to the different concentration of CSE for 24 h and mixed with fluorescein-labeled Escherichia coli in 37℃ for 2 h. The fluorescence intensity was used to assay the phagocytosis function of NR8383 cells.Results The phagocytosis function of NR8383 cells may be changed by the concentration of CSE. In the concentration of 100 μg/ml, the phagocytosis function of NR8383 was enhanced 0.5 times than the normal cell when NR8383 cell was exposed to CSE, and the specific activity is the highest. When NR8383 cells were exposed to CSE and LPS, the phagocytosis function of NR8383 cells was enhanced 2 times than the normal cell. In the concentration of 200 μg/ml, the phagocytosis function of NR8383 cells was damaged, the rate of apoptosis is the 54. 1%. Conclusion Low concentration of CSE enhanced the phagocytosis function of NR8383 cells, but high concentration of CSE damaged the phagocytosis function of NR8383 cells. This study reveals a new role of CSE as an activator of macrophage function.     

Increased tumor necrosis factor-alpha (TNF-alpha) gene expression in parainfluenza type 1 (Sendai) virus-induced bronchiolar fibrosis.

Increased airway resistance and airway hyperresponsiveness induced in rats by infection with parainfluenza type I (Sendai) virus is associated with bronchiolar fibrosis. To determine whether increased tumor necrosis factor (TNF)-alpha gene expression is an important regulatory event in virus-induced bronchiolar fibrosis, pulmonary TNF-alpha mRNA and protein expression was assessed in rat strains that are susceptible (Brown Norway; BN) and resistant (Fischer 344; F344) to virus-induced bronchiolar fibrosis. Virus-inoculated BN rats had increased TNF-alpha pulmonary mRNA levels (P < 0.05) and increased numbers of bronchiolar macrophages and fibroblasts expressing TNF-alpha protein compared with virus-inoculated F344 rats (P < 0.05). Virus inoculation also induced elevated TNF-alpha mRNA and protein levels (P < 0.05) in cultured rat alveolar macrophages (NR8383 cells). A 55-kd soluble TNF receptor-immunoglobulin G fusion protein (sTNFR-IgG) was used to inhibit TNF-alpha bioactivity in virus-inoculated BN rats. Treated rats had fewer proliferating bronchiolar fibroblasts, as detected by bromodeoxyuridine incorporation, compared with virus-inoculated control rats (P < 0.05). There was also increased mortality in p55sTNFR-IgG-treated virus-inoculated rats associated with increased viral replication and decreased numbers of macrophages and lymphocytes in bronchoalveolar lavage fluid (P < 0.05). The results of this study indicate that 1) Sendai virus can directly up-regulate TNF-alpha mRNA and protein expression in macrophages, 2) TNF-alpha is an important mediator of virus-induced bronchiolar fibrosis, and 3) TNF-alpha has a critical role in the termination of Sendai viral replication in the lung.     

Long term iNOS expression in thoracic lymph nodes of silicotic rats

Beside the lung, thoracic lymph nodes are most affected during silicosis. The mechanisms leading to enlargement of the lymph nodes and partial activation of lymph node cells are still unclear. The present study demonstrates an increase in iNOS mRNA expression in the lung draining lymph nodes of rats at 1, 2, and 8 months following silica exposure. Histopathological analysis revealed that iNOS protein was exclusively expressed by macrophages located within the granulomatous areas of the enlarged lymph nodes. In contrast, no differences in mRNA expression and number of iNOS-positive cells were found in the lungs of silica-exposed and non-exposed rats. In vitro experiments showed that silica particles alone did not induce NO release in primary alveolar macrophages (AMs) or the alveolar macrophage cell line NR8383. However, the addition of interferon (IFN)-gamma led to a significant nitric oxide production by primary AMs. NR8383 cells responded only when a combination of IFN-gamma and silica particles was applied. These results indicate that the macrophage activator IFN-gamma, which has already been shown to be expressed at elevated levels by lymphocytes of the silicotic lymph nodes, may be responsible for the long-lasting iNOS expression in thoracic lymph nodes. Our observations support the hypothesis that the mutual activation of lymphocytes and macrophages is a central process in the development of chronic silicosis.     

汉黄芩素对流感病毒感染肺泡巨噬细胞炎症相关因子的影响

目的: 研究汉黄芩素对甲型流感病毒鼠肺适应株A/FM/1/47(H1N1)感染的大鼠肺泡巨噬细胞(NR8383)产生促炎症细胞因子、炎症介质及氧自由基的影响。 方法: 流感病毒感染 NR8383细胞1 h后,加入含汉黄芩素的培养基(终浓度16 mg/L),药物作用后6 h、12 h和24 h,ELISA法检测细胞上清中肿瘤坏死因子α(TNF-α)和单核细胞趋化蛋白 1(MCP-1)的含量,放射免疫测定法检测细胞上清中前列腺素E₂(PGE₂)、磷脂酸A₂(PLA₂)和白三烯B₄(LTB₄)的含量;药物作用后8 h、24 h、36 h和48 h,生化法检测细胞内一氧化氮(NO)含量和诱导型一氧化氮合酶(iNOS)活性,4 h、8 h、18 h和24 h,生化法检测超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量;药物作用后24 h,real-time PCR检测细胞内TNF-α和MCP-1的mRNA水平。 结果: 汉黄芩素抑制了流感病毒感染NR8383细胞后TNF-α、MCP-1的转录和表达(P<0.01),降低了PGE₂、PLA₂、LTB₄和MDA的含量(P<0.05);减少了NO和iNOS的产生(P<0.05),增强了SOD的活性(P<0.05)。 结论: 汉黄芩素明显抑制了流感病毒感染后肺泡巨噬细胞内各种炎症相关因子的产生,具有抗炎作用。     

MD-2 regulates LPS-induced NLRP3 inflammasome activation and IL-1beta secretion by a MyD88/NF-κB-dependent pathway in alveolar macrophages cell line

Myeloid differentiation protein 2 (MD-2) is required in the recognition of lipopolysaccharide (LPS) by toll-like receptor 4 (TLR4), and participates in LPS-induced alveolar macrophage (AM) inflammation during acute lung injury (ALI). Activation of the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome aggravates inflammation in LPS-induced ALI. However, there is currently little known about the relationship between MD-2 signaling and the NLRP3 inflammasome. This study showed that NLRP3 expression, IL-1beta (IL-1β) secretion, and pyroptosis were up-regulated after LPS stimulation in the NR8383 AM cell-line. MD-2 gene knock-down reduced LPS-induced mRNA and protein expression of NLRP3 and IL-1β secretion in NR8383 cells, and inhibited the MyD88/NF-κB signaling pathway. Conversely, over-expression of MD-2 not only heightened NLRP3, MyD88, and NF-κB p65 protein expression, it also aggravated the LPS-induced inflammatory response. Furthermore, the NF-κB inhibitor SN50 had a beneficial role in decreasing NLRP3 and caspase-1 mRNA and protein expression. The observations suggest that MD-2 helps to regulate LPS-induced NLRP3 inflammasome activation and the inflammatory response in NR8383 cells, and likely does so by affecting MyD88/NF-κB signaling.     

Free heme is a danger signal inducing expression of proinflammatory proteins in cultured cells derived from normal rat hearts

Endogenous molecules from damaged tissue act as danger signals to trigger or amplify the immune/inflammatory response. In this study, we examined whether free heme induced pro-inflammatory proteins in cultured cells derived from normal hearts and investigated the cells targeted by heme, together with its mechanism of action in these cells. We cultured collagenase-isolated heart-derived cells from normal rats and examined whether free heme induced pro-inflammatory proteins, reactive oxygen species (ROS) production and NF-κB activation, by quantitative RT-PCR, ELISA and flow cytometry. Free heme increased mRNA of various pro-inflammatory proteins in cultured cardiac resident cells (CCRC) (at least 100-fold) and induced intracellular ROS formation. Approximately 85-90% of CCRC are fibroblast/smooth muscle cells and 10-15% are CD11bc-positive macrophages; therefore to examine individual target cells, macrophage-deleted (CD11bc-negative) CCRC, primary cultured cells (cardiac fibroblasts, arterial smooth muscle cells and cardiac microvascular endothelial cells) and macrophage cells lines (NR8383) were similarly treated. Free heme activated NF-κB and induced expression of some pro-inflammatory proteins, including IL-1 and TNF-α in NR8383. On the other hand, macrophage-deleted CCRC strongly increased expression of these proteins on treatment with IL-1 or TNF-α, but not free heme. Induction of expression of pro-inflammatory proteins by free heme was not inhibited by intracellular ROS reduction, but by protease and proteasome inhibitors capable of regulating NF-κB. These data suggest that free heme strongly induces various pro-inflammatory proteins in injured hearts through NF-κB activation in cardiac resident macrophages and through cross-talk between macrophages and fibroblast/smooth muscle cells mediated inter alia by IL-1, TNF-α.     

Immunosuppressive properties of surfactant in alveolar macrophage NR8383

Objective: To evaluate the anti-inflammatory effects of exogenous surfactants and surfactant phospholipid without surfactant proteins (SP-A and SP-D) on the lipopolysaccharide- (LPS) stimulated rat alveolar macrophage (AM) cell line NR8383. Methods: Exogenous surfactants (beractant, calfactant or colfosceril) and surfactant phospholipid (dipalmitoyl phosphatidylcholine, DPPC), standardized to phospholipid content of 25–1,000 μg/ml were incubated with LPS- (1 μg/ml) stimulated NR8383 AMs. Results: TNF-α and IL-1β secretion and nitric oxide (NO) formation following LPS stimulation were inhibited by treatment with surfactants or DPPC. Furthermore, LPS-dependent NO production and iNOS protein levels were significantly suppressed in cells pretreated for one hour with beractant compared to beractant added simultaneously with or following LPS. Additionally, LPS-stimulated oxidative burst, measured by flow cytometry, was significantly decreased by beractant. Finally, beractant inhibited the translocation of NF-κB from cytoplasmic into nuclear extract in LPS-stimulated NR8383 AMs. Conclusions: Exogenous surfactants and surfactant phospholipid inhibit secretion of proinflammatory cytokines and NO in NR8383 AMs. The inhibitory effects of beractant on oxygen radical and LPS-induced NO formation may result from unique mechanisms of decreasing cell signaling. The anti-inflammatory activity of surfactant products used in the treatment of neonatal respiratory distress syndrome (RDS) may depend upon the specific preparation or dose used. Received 28 December 2006; returned for revision 4 July 2007; accepted by S. Stimpson 29 October 2007     

Time Course of Expression of “Early” Genes during Long-Term Posttetanic Potentiation in Rat Hippocampal CA1 Field

The expression of egr-1, junB, c-jun, and c-fos genes in rat hippocampal CA1 fi eld was studied by the real-time PCR 30, 60, and 120 min after induction of long-term posttetanic potentiation. The content of egr-1, junB, and c-jun mRNA gradually increased and doubled 120 min after tetanization. The increase in c-jun mRNA level lagged behind the increment of egr-1 and junB. The level of c-fos mRNA increased 30 min after tetanization, returned to the initial level by min 60, and again increased 120 min after induction of long-term posttetanic potentiation.