Monocyte-macrophage Cells Research Articles

Cytotoxicity and Characterization of Particles Collected From an Indium–Tin Oxide Production Facility

Occupational exposure to indium compound particles has recently been associated with lung disease among workers in the indium–tin oxide (ITO) industry. Previous studies suggested that excessive alveolar surfactant and reactive oxygen species (ROS) may play a role in the development of pulmonary lesions following exposure to indium compounds. However, toxicity at the cellular level has not been comprehensively evaluated. Thus, the aim of this study was to assess which, if any, compounds encountered during ITO production are toxic to cultured cells and ultimately contribute to the pathogenesis of indium lung disease. The compounds used in this study were collected from eight different processing stages at an ITO production facility. Enhanced dark field imaging showed 5 of the compounds significantly associated with cells within 1 h, suggesting that cellular reactions to the compound particles may be occurring rapidly. To examine the potential cytotoxic effects of these associations, ROS generation, cell viability, and apoptosis were evaluated following exposures in RAW 264.7 mouse monocyte macrophage and BEAS-2B human bronchial epithelial cell lines. Both exhibited reduced viability with exposures, while apoptosis only occurred in RAW 264.7 cells. Our results suggested that excessive ROS production is likely not the predominant mechanism underlying indium-induced lung disease. However, the effects on cell viability reveal that several of the compounds are cytotoxic, and therefore, exposures need to be carefully monitored in the industrial setting.

The Effect of Tungstate Nanoparticles on Reactive Oxygen Species and Cytotoxicity in Raw 264.7 Mouse Monocyte Macrophage Cells

Due to their unique size, surface area, and chemical characteristics, nanoparticles’ use in consumer products has increased. However, the toxicity of nanoparticle (NP) exposure during the manufacturing process has not been fully assessed. Tungstate NP are used in numerous products, including but not limited to scintillator detectors and fluorescent lighting. As with many NP, no apparent toxicity studies have been completed with tungstate NP. The hypothesis that tungstate NP in vitro exposure results in reactive oxygen species (ROS) formation and cytotoxicity was examined. Differences in toxicity based on tungstate NP size, shape (sphere vs. wire), and chemical characteristics were determined. RAW 264.7 mouse monocyte macrophages were exposed to tungstate NP, and ROS formation was assessed via electron spin resonance (ESR), and several assays including hydrogen peroxide, intracellular ROS, and Comet. Results showed ROS production induced by tungstate nanowire exposure, but this exposure did not result in oxidative DNA damage. Nanospheres showed neither ROS nor DNA damage following cellular exposure. Cells were exposed over 72 h to assess cytotoxicity using an MTT (tetrazolium compound) assay. Results showed that differences in cell death between wires and spheres occurred at 24 h but were minimal at both 48 and 72 h. The present results indicate that tungstate nanowires are more reactive and produce cell death within 24 h of exposure, whereas nanospheres are less reactive and did not produce cell death. Results suggest that differences in shape may affect reactivity. However, regardless of the differences in reactivity, in general both shapes produced mild ROS and resulted in minimal cell death at 48 and 72 h in RAW 264.7 cells.

Vitamin D and rheumatic diseases.

Vitamin D has some well-known effects on calcium, phosphate and bone metabolism, but it has recently shown to have many other effects, which may potentially be relevant to patients with extra-skeletal rheumatic diseases. Such effects may be justified by: 1) the presence of the vitamin D receptors also on extra-osseous cells, such as cartilage cells, sinoviocytes, muscle cells; 2) the proven role of vitamin D in the control of the transcription of genes involved in rheumatic diseases; 3) the evidence that vitamin D has multiple endocrine effects not only on calcium homeostasis; 4) the activation of vitamin D not only in the kidneys, but also in monocyte-macrophage and lymphocytic cell lines and in some epithelial cells with additional intracrine and paracrine effects. Vitamin D deficiency has been reported in numerous metabolic, degenerative, inflammatory and autoimmune rheumatic diseases. In some cases this association was also related to the risk of developing a rheumatic disease or the degree of disease activity. However there is no conclusive evidence of the efficacy of a preventive or therapeutic strategy based on vitamin D supplementation in extra-skeletal rheumatic diseases. This review aims to provide an overview of the latest evidence concerning the relationship between vitamin D and the most relevant rheumatic diseases.

Monocyte Kinetics and Dynamics in Heart Transplant Recipients.

Background and Methods: Monocyte-macrophage lineage cells are key players in graft rejection and tolerance. To investigate whether local events in transplanted hearts are reflected in the circulating monocyte population, we investigated in 10 heart transplant recipients the monocyte subset composition and their phenotypic and functional characteristics at rejection vs. no rejection time points by flowcytometry. The rejection status was determined by transplant biopsy analysis. In addition, using a cross-sectional approach, we compared the monocyte kinetics in heart transplant recipients with a cohort of 33 healthy individuals. Results: Comparing the monocyte subsets from heart transplant recipients with those from healthy individuals, we observed an increased percentage of the CD14++16-classical monocytes and a simultaneous decrease in the percentage of CD14++16+ intermediate and CD14+16++ non-classical monocytes. However, no intra-individual differences were observed between rejection and non-rejection time points. After stimulation of monocytes with both LPS, and with MLR-activated donor-derived spleen cells, the capacity to produce TNF-α, IFN-γ, IL-1β, IL-6, and IL-10 was consistently high in heart transplant recipients, independent of rejection status, and comparable to healthy individuals. Increased HLA-DR expression was observed in heart transplant recipients compared to healthy individuals in all monocyte subsets indicative of a higher potential for antigen presentation. HLA-DR expression on CD16+ monocytes was even more increased during rejection compared to non-rejection time points. Conclusion: Increased percentage of CD14++16- classical monocytes and decreased percentages of CD14++16+ intermediate and CD14+16++ non-classical monocytes signify the monocyte kinetics in heart transplant recipients as compared to healthy individuals. We observed no differences in monocyte subset composition at rejection compared with non-rejection. Remarkably, despite the immunosuppressive drugs, the monocyte-derived cytokine production in heart transplant recipients was consistently high and comparable with healthy individuals.

Cytokine-mediated bone resorption

Osteoclasts, the multinucleated cells that resorb bone, originate from monocyte-macrophage lineage cells. Various hormones, cytokines and growth factors are involved in osteoclastogenesis, via interaction with osteoblasts. In this review, we summarize the regulatory mechanism of bone resorption by various cytokines derived from osteoblasts and hematopoietic inflammatory cells.

Safety, functionality and stability tests of Ecklonia cava extract for dermal application

Ecklonia cava demonstrated anti-Propionibacterium acnes and anti-inflammatory activity, without any serious toxic effect, at moderate doses in an in vitro study. However, there has been no in vivo study on dermal application of E. cava extract. We evaluated the safety, functionality, and stability of a cosmetic containing E. cava extract for dermal administration. A cytotoxicity assay revealed no inhibitory effects on cell viability in a mouse leukemic monocyte macrophage cell line (RAW 264.7) after incubation with 100 μg/mL of the E. cava acetone fraction (ECAF) for 24 h. The anti-P. acnes activity of ECAF was not affected by any significant variation in temperature, pH, or exposure to artificial UV light or natural sunlight. ECAF also showed negative reactions in a patch test. No change in appearance, color, or odor was observed in a stability test on an emulsion product with ECAF. On the basis of these results, it is expected that ECAF will be a very useful or applicable raw material for skin goods such as cosmetics for treating or improving acne.

BMP-2 and titanium particles synergistically activate osteoclast formation.

A previous study showed that BMP-2 (bone morphogenetic protein-2) and wear debris can separately support osteoclast formation induced by the receptor activator of NF-κB ligand (RANKL). However, the effect of BMP-2 on wear debris-induced osteoclast formation is unclear. In this study, we show that neither titanium particles nor BMP-2 can induce osteoclast formation in RAW 264.7 mouse leukemic monocyte macrophage cells but that BMP-2 synergizes with titanium particles to enhance osteoclast formation in the presence of RANKL, and that at a low concentration, BMP-2 has an optimal effect to stimulate the size and number of multinuclear osteoclasts, expression of osteoclast genes, and resorption area. Our data also clarify that the effects caused by the increase in BMP-2 on phosphorylated SMAD levels such as c-Fos expression increased throughout the early stages of osteoclastogenesis. BMP-2 and titanium particles stimulate the expression of p-JNK, p-P38, p-IkB, and P50 compared with the titanium group. These data suggested that BMP-2 may be a crucial factor in titanium particle-mediated osteoclast formation.

Blockade of CD26 signaling inhibits human osteoclast development.

Bone remodeling is maintained by the delicate balance between osteoblasts (OBs) and osteoclasts (OCs). However, the role of CD26 in regulating bone remodeling has not yet been characterized. We herein show that CD26 is preferentially expressed on normal human OCs and is intensely expressed on activated human OCs in osteolytic bone alterations. Macrophage-colony stimulating factor (M-CSF) and soluble receptor activator of NF-κB ligand (sRANKL) induced human OC differentiation, in association with CD26 expression on monocyte-macrophage lineage cells. CD26 expression was accompanied by increased phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), which is crucial for early human OC differentiation. The humanized anti-CD26 monoclonal antibody, huCD26mAb, impaired the formation and function of tartrate-resistant acid phosphatase (TRAP)/CD26 positive multi-nucleated (nuclei > 3) OCs with maturation in the manner of dose-dependency. It was revealed that huCD26mAb inhibits early OC differentiation via the inactivation of MKK3/6, p38 MAPK and subsequent dephosphorylation of microphthalmia-associated transcription factor (mi/Mitf). These inhibitions occur immediately after RANKL binds to RANK on the human OC precursor cells and were demonstrated using the OC functional assays. huCD26mAb subsequently impaired OC maturation and bone resorption by suppressing the expression of TRAP and OC fusion proteins. In addition, p38 MAPK inhibitor also strongly inhibited OC formation and function. Our results suggest that the blockade of CD26 signaling impairs the development of human functional OCs by inhibiting p38 MAPK-mi/Mitf phosphorylation pathway and that targeting human OCs with huCD26mAb may have therapeutic potential for the treatment of osteolytic lesions following metastasis to alleviate bone destruction and reduce total skeletal-related events (SREs).

Characteristics and cellular effects of ambient particulate matter from Beijing

In vitro tests using human adenocarcinomic alveolar epithelial cell line A549 and small mouse monocyte-macrophage cell line J774A.1 were conducted to test toxicity of six PM (particulate matter) samples from Beijing. The properties of the samples differ significantly. The production of inflammatory cytokine (TNF-α for J774A.1) and chemokine (IL-8 for A549) and the level of intracellular reactive oxygen species (ROS) were used as endpoints. There was a positive correlation between water soluble organic carbon and DTT-based redox activity. Both cell types produced increased levels of inflammatory mediators and had higher level of intracelllar ROS, indicating the presence of PM-induced inflammatory response and oxidative stress, which were dose-dependent and significantly different among the samples. The releases of IL-8 from A549 and TNF-α from J774A.1 were significantly correlated to PM size, Zeta potential, endotoxin, major metals, and polycyclic aromatic hydrocarbons. No correlation between ROS and these properties was identified.

The nuclear factor kappa B (NF-κB) activation is required for phagocytosis of staphylococcus aureus by RAW 264.7 cells

Nuclear factor kappa B (NF-κB) is a ubiquitous transcription factor which controls the expression of various genes involved in immune responses. However, it is not clear whether NF-κB activation is critical for phagocytosis when Staphylococcus aureus is the pathogen. Using oligonucleotide microarrays, we investigated whether NF-κB cascade genes are altered in a mouse leukemic monocyte macrophage cell line (RAW 264.7) when the cells were stimulated to activate a host innate immune response against live S. aureus or heat-inactivated S. aureus (HISA). NF-κB cascade genes such as Nfκb1, Nfκbiz, Nfκbie, Rel, Traf1 and Tnfaip3 were up-regulated by all treatments at one hour after incubation. NF-κB play an important role in activating phagocytosis in RAW 264.7 cells infected with S. aureus. Inhibition of NF-κB significantly blocked phagocytosis of fluorescently labeled S. aureus and decreased the expression of NFκB1, IL1α, IL1β and TLR2 in this cell line. Our results demonstrate that S. aureus may activate the NF-κB pathway and that NF-κB activation is required for phagocytosis of S. aureus by macrophages.

Novel signaling function of hCLCA1 in airway macrophages activation (1095.2)

The CLCA gene family produces both secreted and membrane‐associated proteins that modulate ion‐channel function, drive mucus production and have a poorly understood pleiotropic effect on airway inflammation. In airway inflammation, the primary up‐regulated human CLCA ortholog is hCLCA1. Here we show that secreted hCLCA1 is able to activate macrophages, inducing them to express cytokines and to undertake a pivotal role in airway inflammation. Conditioned media collected from HEK293 cells heterologously expressing hCLCA1 increased the expression of pro‐inflammatory cytokines (IL‐1β, IL‐6, TNF‐α, and IL‐8) in U‐937 monocyte‐macrophage cell line. Similar pro‐inflammatory response was achieved in primary porcine alveolar macrophages activated with hCLCA1 conditioned media, showing that the effect was not cell line dependent. Immuno‐purified hCLCA1 at physiologically relevant concentration of ~100 pg/mL was also able to elicit pro‐inflammatory response in macrophages. These findings demonstrating that secreted hCLCA1 is able to function as a signaling molecule and to regulate cytokine expression in macrophages.Grant Funding Source: NSERC

CCAAT Enhancer Binding Protein and Nuclear Factor of Activated T Cells Regulate HIV-1 LTR via a Novel Conserved Downstream Site in Cells of the Monocyte-Macrophage Lineage

Transcriptional control of the human immunodeficiency virus type 1 (HIV-1) promoter, the long terminal repeat (LTR), is achieved by interactions with cis-acting elements present both upstream and downstream of the start site. In silico transcription factor binding analysis of the HIV-1 subtype B LTR sequences revealed a potential downstream CCAAT enhancer binding protein (C/EBP) binding site. This binding site (+158 to+172), designated DS3, was found to be conserved in 67% of 3,858 unique subtype B LTR sequences analyzed in terms of nucleotide sequence as well as physical location in the LTR. DS3 was found to be well represented in other subtypes as well. Interestingly, DS3 overlaps with a previously identified region that bind members of the nuclear factor of activated T cells (NFAT) family of proteins. NFATc2 exhibited a higher relative affinity for DS3 as compared with members of the C/EBP family (C/EBP α and β). DS3 was able to compete efficiently with the low-affinity upstream C/EBP binding site I with respect to C/EBP binding, suggesting utilization of both NFAT and C/EBP. Moreover, cyclosporine A treatment, which has been shown to prevent dephosphorylation and nuclear translocation of NFAT isoforms, resulted in enhanced C/EBPα binding. The interactions at DS3 were also validated in an integrated HIV-1 LTR in chronically infected U1 cells. A binding knockout of DS3 demonstrated reduced HIV-1 LTR-directed transcription under both basal and interleukin-6-stimulated conditions only in cells of the monocyte-macrophage lineage cells and not in cells of T-cell origin. Thus, the events at DS3 positively regulate the HIV-1 promoter in cells of the monocyte-macrophage lineage.

Cytotoxicity and single-dose oral toxicity testing for rice bran supercritical CO2 extract

The aim of this study was to evaluate the toxicity of rice bran supercritical CO2 extract (RB-SCE) in vitro and in vivo. A cytotoxicity assay revealed no inhibitory effects on cell viability in a mouse leukemic monocyte macrophage cell line (RAW 264.7) after 24-h incubation with 0.16 or 0.32 μg/mL of RB-SCE. RB-SCE was administered to male and female Sprague-Dawley rats at 2,500, 5,000, or 10,000 mg/kg to evaluate acute oral toxicity. Mortality, clinical symptoms, and body weight changes were monitored for two weeks. Animals were then euthanized and necropsies performed. Clinical symptoms included soft stool, diarrhea, and soiled perineal region. No significant changes in body weight were observed in treatment groups compared to the control. In addition, necropsy revealed no abnormal finding at any dosage. The approximate lethal dose (ALD) of RB-SCE was estimated at >10,000 mg/kg for both sexes and orally administered RBSCE was deemed safe.

Synthesis, antimicrobial and cytotoxic evaluation of 4-(1-aryl-5-halo-2-oxo-1,2-dihydro-indol-3-ylideneamino)-N-substituted benzene sulfonamides

In the present study, a series of 4-(1-aryl-5-chloro-2-oxo-1,2-dihydro-indol-3-ylideneamino)-N-substituted benzene sulfonamides (1–20) was synthesized and screened for their in vitro antimicrobial activity against Gram positive, Gram negative bacterial and fungal strains indicating that compound 19 (N-(4-(5-Bromo-1-(4-chlorobenzoyl)-2-oxoindolin-3-ylideneamino)phenylsulfonyl)-4-isopropoxybenzamide) was found to be the most active antimicrobial agent. The anticancer activity of synthesized compounds against mouse leukemic monocyte macrophage cell line (RAW 264.7) and colon cancer (HCT116) cell lines indicated that compound 16 (4-(5-Bromo-1-(4-chlorobenzoyl)-2-oxoindolin-3-ylideneamino)-N-(4,6-dimethylpyrimidin-2-yl)benzene sulfonamide) was found to be the most potent cytotoxic agent against HCT116 and compounds 17 (4-(5-Bromo-1-(4-chlorobenzoyl)-2-oxoindolin-3-ylideneamino)-N-(6-methoxypyridazin-3-yl)benzene sulfonamide) and 19 (N-(4-(5-Bromo-1-(4-chlorobenzoyl)-2-oxoindolin-3-ylideneamino)phenylsulfonyl)-4-isopropoxybenzamide) were found to be the most potent cytotoxic agents against RAW264.7 cancer cell lines.

A role for immunotherapy: preventing macrophage anergy in the tumour environment

The tumour microenvironment is shaped by the interaction of tumour cells with a variety of “non” malignant cellular and acellular components. It is the secretion of cytokines, chemokines, metabolites and other mediators in the tumour stroma that shapes the natural evolution of cancer. Whereas the tumour strives to promote an immunosuppressive environment to limit anti-tumour immune response, infiltrating immune cells aim to control tumour growth. The balance between these two conflicting interests shapes the immune contexture of cancer and ultimately patient prognosis. In an effort to characterize the role played by macrophages, we have developed an in vitro system using human pancreatic tumour cell lines and a human monocyte-macrophage leukemic cell line (ThP1). We have investigated the immunosuppressive properties of pancreatic cancer cell lines and how the immune properties of macrophages are influenced by the tumour supernatant in vitro. We have applied our findings to a clinically relevant murine model of pancreatic cancer. We found that, despite some heterogeneity, the profile of MIAPACA-2, BxPC3 and PANC-1, included IL-8, MCP-1, SCF and VEGF secretion. Not surprisingly, when ThP1 cell were cultured in the presence of increasing concentrations of tumour supernatant and stimulated with LPS, we observed a significant downregulation of their ability to produce cytokines associated with an M1 profile (e.g. IL-6, IL-12p70, IL-23, TNF-α). However, ThP1 also failed to display an M2 profile; IL-10 and IL-1ra were similarly downregulated. ThP1 stimulated with LPS in the presence of tumour supernatant also had impaired secretion of a number of other cytokines such as IL-18, MIP-1α and MIP-1β and MCP-1. In contrast, they appeared to maintain secretion of VEGF and IL-7. Next we investigated how the immune stimulant IMM-101, an immunotherapeutic agent comprising heat-killed whole cell Mycobacterium obuense, might be able to shift this anergic phenotype. IMM-101 is currently under clinical evaluation in two Phase II clinical trials in pancreatic (EudraCT number 2010-022757-42) and colorectal cancer (EudraCT number 2011-003958-85). We found that despite the presence of tumour supernatant, macrophages stimulated with IMM-101 retained the ability to secrete the full range of cytokines and we did not observe the impairment reported after LPS stimulation. We believe the immunological properties of IMM-101 make this a potential candidate for successful immunotherapy.

Properties and Inflammatory Effects of Various Size Fractions of Ambient Particulate Matter from Beijing on A549 and J774A.1 Cells

Particulate matter (PM) is a major ambient air pollutant causing millions of premature deaths each year in China. The toxicity of PM is property and size dependent. In this study, ambient PM samples collected in Beijing were divided into five size fractions with nominal aerodynamic ranges of <0.40, 0.40-1.1, 1.1-3.3, 3.3-5.8, and 5.8-10 μm. Individual size fractions were characterized for a number of properties including particle size distribution, specific surface area, zeta potential, dithiothreitol (DTT)-based redox ability, and contents of water-soluble organic carbon (WSOC), polycyclic aromatic hydrocarbons (PAHs), selected metals, and endotoxin. Human adenocarcinomic alveolar epithelial cell line A549 and small mouse monocyte-macrophage cell line J774A.1 were tested for their relative viabilities and inflammatory effects (interleukine-8 for A549 and tumor necrosis factor-α for J774A.1) after exposure to PM of various sizes. It was found that PM specific area was positively correlated with WSOC, high molecular weight PAHs, DTT-based redox ability, negatively correlated with surface zeta potential and lithophile metals. Several trace metals from combustion sources were enriched in intermediate size fractions. For both endotoxin concentrations of the PM and PM induced inflammatory cytokine expressions by the two cell lines, there were general increasing trends as PM size increased with an exception of the finest fraction, which induced the highest inflammatory effects. It seems that the size dependence of cytokine expression was associated with a number of properties including endotoxin content, zeta potential, settling velocity, metal content, and DTT-based redox ability.

A Shift towards Pro-Inflammatory CD16+ Monocyte Subsets with Preserved Cytokine Production Potential after Kidney Transplantation

BackgroundThe presence of monocyte-macrophage lineage cells in rejecting kidney transplants is associated with worse graft outcome. At present, it is still unclear how the monocyte-macrophage related responses develop after transplantation. Here, we studied the dynamics, phenotypic and functional characteristics of circulating monocytes during the first 6 months after transplantation and aimed to establish the differences between kidney transplant recipients and healthy individuals.MethodsPhenotype, activation status and cytokine production capacity of classical (CD14++CD16−), intermediate (CD14++CD16+) and non-classical (CD14+CD16++), monocytes were determined by flow cytometry in a cohort of 33 healthy individuals, 30 renal transplant recipients at transplantation, 19 recipients at 3 months and 16 recipients at 6 months after transplantation using a cross-sectional approach.ResultsThe percentage of both CD16+ monocyte subsets was significantly increased in transplant recipients compared to healthy individuals, indicative of triggered innate immunity (p≤0.039). Enhanced production capacity of tumor necrosis factor-α, interferon-γ and interleukin-1β was observed by monocytes at transplantation compared to healthy individuals. Remarkably, three months post-transplant, in presence of potent immunosuppressive drugs and despite improved kidney function, interferon-γ, tumor necrosis factor-α and interleukin-10 production capacity still remained significantly increased.ConclusionOur data demonstrate a skewed balance towards pro-inflammatory CD16+ monocytes that is present at the time of transplantation and retained for at least 6 months after transplantation. This shift could be one of the important drivers of early post-transplant cellular immunity.

MC3T3‐E1 and RAW264.7 cell response to hydroxyapatite and alpha‐type alumina adsorbed with bovine serum albumin

Initial cell responses following implantation are important for inducing osteoconductivity. We investigated cell adhesion, spreading, and proliferation in response to native and bovine serum albumin (BSA)-adsorbed disc of hydroxyapatite (HA) or alpha-type alumina (α-Al2O3) using mouse MC3T3-E1 osteoblastic cells and mouse RAW264.7 macrophages. The adsorbed BSA inhibited adhesion and spreading of MC3T3-E1 cells, but did not affect MC3T3-E1 cell proliferation on HA and α-Al2O3 substrates. Thus, MC3T3-E1 cells quickly adhere to original HA before cell binding is impeded by adsorption of BSA in quantities sufficient to inhibit the adhesion of MC3T3-E1 cells. The adsorbed BSA inhibits adhesion of RAW264.7 cells to α-Al2O3, but not to HA. BSA adsorption does not affect RAW264.7 cell spreading and proliferation on both HA and α-Al2O3 substrates. Thus, BSA adsorbed on HA stimulates a different cell response than α-Al2O3. Moreover, quick adherence of osteoblast cells and monocyte-macrophage lineage cells plays a role in HA osteoconductivity.

The effects of intravenous immunoglobulin on the concentration of prostaglandin E2 in plasma of patients with Kawasaki disease

Objective To investigate the effects of intravenous immunoglobulin (IVIG) on the concentration of prostaglandin E2 (PGE2) in plasma of patients with Kawasaki disease (KD).Methods Twenty-five hospitalized patients with KD in Shenzhen Children's Hospital from February to August 2012 were enrolled in the study.Fifteen healthy children at the same age were selected as the control group.The concentrations of PGE2,cyclooxygenases-2 (COX-2),hemeoxygenase-1 (HO-1),nuclear factor-erythroid 2-related factor-2 (Nrf2) and tumor necrosis factor-α (TNF-α) in plasma were analyzed by sandwich enzyme-linked immunosorbent assay(ELISA) before and after IVIG treatment.The reverse transcription-polymerase chain reaction (RT-PCR) and real-time quantitative PCR were used to evaluate the expressions of COX-2,HO-1,Nrf2,interleukin-6 (IL-6) and TNF-α in peripheral blood CD14+ monocyte/macrophage cells (MCs) before and after IVIG treatment.Results The expressions of PGE2,COX-2,IL-6 and TNF-α in patients with acute KD were higher than those in the control group (P＜0.05),but the expressions of HO-1 and Nrf2 were lower than those in the control group(P＜0.05).After the IVIG treatment,the expressions of PGE2,COX-2,IL-6 and TNF-α were significantly down-regulated (P ＜ 0.05) whereas the expressions of HO-1 and Nrf2 were significantly up-regulated (P＜0.05) in patients with acute KD.Conclusion PGE2 plays an important role in immune status,inflammatory response and oxidative stress of KD patients.The IVIG treatment might regulate PGE2 expression in patients with KD through regulating COX-2/HO-1/Nrf2-ARE signaling pathway. Key words: Kawasaki disease; Prostaglandin E2; Cyclooxygenases-2; Hemeoxygenase-1; Nuclear factor-erythroid 2-related factor-2

Formation mechanisms of multinucleated giant cells in mycobacterial infection

Multinucleated giant cell ( MGC ) is one of the characteristic pathological cells in infections with Mycobacterium species,especially Mycobacterium tuberculosis (MTB).Typical MGCs have large volume with multiple nuclei in a ringlike or horseshoe-shaped arrangement in the cytoplasm.In general,MGCs are formed by the differentiation and fusion of monocyte-macrophage cells in the microenvironment of granuloma.Although MGCs have been discovered for a long time,little is known about their formation mechanism,function,and significance for host and mycobacteria.Many studies have shown that the formation and functional changes of MGCs are affected by some components and secreted proteins of mycobacteria,numerous cytokines and adhesion factors in the microenvironment of granuloma,cell surface antigen,and so on. Key words: Mycobacteriaceae ; Giant cells ; Granuloma ;