OBJECTIVETo study the effects of Lipopolysaccharide (LPS) on the maturation and secretion of human peripheral dendritic cells (DCs).

METHODSDCs from healthy human peripheral monocytes (PBMCs) were induced in vitro with rhGM-CSF, rhIL-4, Flt3-L and TNFalpha. The subjects were divided into 3 groups: the long-term group stimulated with LPS 1 microg/ml at day 1, 4, 7, 9 post culture; the short-term group stimulated with LPS 1 microg/ml at day 7 and 8 post culture, and the DCs without LPS stimulation was control group. After 10 days of culture, the morphologic features of DCs were observed by light and electron microscopes, the phenotypic patterns were characterized by flow cytometry, the proliferation of T cell were evaluated with mixed leukocytes reaction (MLR) and the levels of IL-12 and IFNgamma produced by DCs were analyzed with ELISA.

RESULTSCompared with the short-term group, the expressions of HLA-DR (65.81%+/-10.96%), CD86 (48.81%+/-18.13%), CD80 (13.56%+/-5.48%), CD83 (11.52%+/-5.09%), the secretions of IFNgamma(15.60+/-5.83 pg/ml) and IL-12 (51.77+/-11.02 pg/ml) by the DCs in long-term group were decreased obviously (P is less than 0.05) and the proliferation of homogenic lymphocyte cells (1.548+/-0.365) stimulated by DCs was also impaired (P < 0.05).

CONCLUSIONLong-term LPS stimulation can suppress the maturation and secretion of DCs, which might be the reason of poor immunity in the patients with intestinal endotoxemia.

Cells, Cultured ; Dendritic Cells ; cytology ; drug effects ; metabolism ; Humans ; Interleukin-12 ; biosynthesis ; Lipopolysaccharides ; pharmacology ; Monocytes ; cytology ; metabolism

The study was aimed to investigate the mechanism of mannan-binding lectin (MBL) on bacterial lipopolysaccharide (LPS)-induced human peripheral blood monocyte-derived dendritic cell (DC) maturation. The monocytes were prepared from the peripheral blood of healthy adult volunteers. The immature dendritic cells (imDC) were induced by 5-day-culture in medium supplemented with rhGM-CSF and rhIL-4. FACS was used to investigate the interaction of MBL with imDC and the impact of MBL on LPS binding to imDC. ELISA and Western blot was used to analyze the interaction of MBL with soluble TLR4 ectodomain protein (sTLR4); Western blot was used to detect LPS-induced NF-κB translocation in imDC. The results showed that MBL could directly bind to imDC in the presence of calcium. sTLR4 protein or LPS could competitively inhibit the binding of MBL to imDC. ELISA and Western blot showed that MBL could evidently bind to sTLR4 protein in a concentration-dependent manner. FACS showed that MBL could competitively inhibit the binding of LPS to imDC by binding to imDC directly. Western blot showed that MBL decreased LPS-induced NF-κB translocation in imDC. It is concluded that MBL may competitively inhibit the binding of LPS to imDC by binding to TLR4 expressed on imDC, resulted in inhibition of LPS-induced DC maturation, suggesting that MBL can regulate DC maturation through ligand-binding. This study provides the good foundation to clarify the mechanism of MBL inhibiting the LPS-induced DC maturation.
Cell Differentiation ; Cells, Cultured ; Dendritic Cells ; cytology ; drug effects ; metabolism ; Humans ; Ligands ; Lipopolysaccharides ; adverse effects ; Mannose-Binding Lectin ; pharmacology ; Monocytes ; cytology ; metabolism ; Toll-Like Receptor 4 ; metabolism

OBJECTIVEDendritic cells an hyperinsulinemia are both implicated in the pathogenesis of atherosclerosis. The aim of this study is to explore the effect of high concentration of insulin on the maturation of monocyte-derived dendritic cells (MoDCs) and related signal transduction pathways.

METHODSHuman monocytes were purified (over 98%) using Anti-CD14 micro-beads and cultured for 5 days with DC Cellgro medium containing rhGM-CSF (100 microg/L) and rhIL-4 (20 microg/L). Immature DC were then incubated with insulin of various concentrations (0, 1, 10, 100 nmol/L) for 24 hours in the presence or absence of LY294002 (PI3K inhibitor) or PD98059 (MAPK inhibitor). Immunophenotypic expression of CD86 and CD83 were detected using flow cytometry. Endocytosis function of the MoDCs was evaluated using FITC-Dextran and MoDCs secretion IL-12, IFN-gamma and TNF-alpha were measured by ELISA.

RESULTSInsulin induced significantly higher CD83 and CD86 expressions on MoDCs in a dose-dependent manner. The endocytosis function of MoDCs were significantly inhibited and cytokine secretions of IL-12, IFN-gamma and TNF-alpha significantly increased by 10 nmol/L and 100 nmol/L insulin. These effects could be blocked by the LY294002 and PD98059.

CONCLUSIONHyperinsulinemia contributed to atherosclerosis via stimulating immune maturation of MoDCs via both PI3K and MAPK pathways.

Cell Differentiation ; drug effects ; immunology ; Cells, Cultured ; Cytokines ; metabolism ; Dendritic Cells ; drug effects ; immunology ; metabolism ; Humans ; Insulin ; administration & dosage ; pharmacology ; Monocytes ; cytology ; Phagocytosis ; drug effects ; Signal Transduction

OBJECTIVETo observe the expression and localization of endogenous C-reactive protein (CRP) in cells from different tissues under different conditions.

METHODSMacrophages differentiated from THP-1 monocytes with phorbol ester (PMA) induction and human LO2 hepatocytes were stimulated with lipopolysaccharide (LPS). The culture supernatant of the LPS-stimulated THP-1 cells was collected and added into LO2 cell culture, and after incubation, the cells were lysed to extract the proteins for SDS-PAGE and Western blotting. The stimulated cells were also examined immunocytochemically for CRP expression.

RESULTSWestern blotting detected CRP in both of the unstimulated cell lysates, but in neither of the two cell supernatants. After LPS stimulation, CRP expression was significantly increased in the cell lysate of THP-1 cells with also a small amount present in the supernatant, but CRP expression and release in the LO2 cells showed no significant variation. Treatment of the LO2 cells with the culture supernatant of LPS-stimulated THP-1 cells resulted in positivity of CRP in the cell lysate and the culture supernatant. Immunocytochemistry identified CRP expression throughout the THP-1 cell body (most obvious in the nuclei), which increased after LPS stimulation. In LO2 hepatocytes, CRP expression was found only outside the nuclei and increased after stimulation with the culture supernatant of LPS-treated THP-1 cells, especially obvious around the membrane.

CONCLUSIONCRP can not be up-regulated directly by LPS treatment in LO2 cells, but can be induced by certain cytokines (IL-6) secreted from LPS-stimulated THP-1 cells. The localization of CRP represents the characteristics of secreted protein in LO2 cells, but in THP-1 cells, CRP is found mainly in the cell nuclei.

Blotting, Western ; C-Reactive Protein ; biosynthesis ; Cell Differentiation ; drug effects ; Cell Line ; Culture Media, Conditioned ; pharmacology ; Hepatocytes ; cytology ; drug effects ; metabolism ; Humans ; Immunohistochemistry ; Lipopolysaccharides ; pharmacology ; Macrophages ; cytology ; Monocytes ; cytology ; drug effects ; metabolism

Human 8-oxo-G-DNA glycosylase 1 (hOGG1) is a DNA glycosylase to cleave 8-oxo-7,8-dihydroguanine (8-oxo-G), a mutagenic DNA adduct formed by oxidant stresses. Here, we examined hOGG1 protein expression and repair activity to nick a DNA strand at the site of 8-oxo-G during differentiation of hematopoietic cells using HL-60 cells. Overall expression of hOGG1 protein was increased during granulocytic differentiation of HL-60 cells induced by DMSO and monocytic differentiation by vitamine D3. Greater level of hOGG1 protein was expressed in DMSO-treated cells. However, change in the DNA nicking activity was not in parallel with the change in hOGG1 protein expression, especially in PMA-treated cells. In PMA- treated cells, the level of hOGG1 protein was lowered, even though the DNA nicking activity was elevated, in a manner similar to the changes in serum- deprived HL-60 cells. These results indicate that hOGG1 expression change during differentiation of hematopoietic stem cells for adaptation to new environments. And the DNA cleaving activity may require additional factor(s) other than expressed hOGG1 protein, especially in apoptotic cell death.
Blotting, Western ; *Cell Differentiation ; Culture Media, Serum-Free/pharmacology ; DNA Glycosylases/*metabolism ; Enzyme Activation ; *Gene Expression Regulation, Enzymologic/drug effects ; Granulocytes/cytology/drug effects/metabolism ; HL-60 Cells ; Human ; Monocytes/cytology/drug effects/metabolism

OBJECTIVEDendritic cells play an important role in the pathogenesis of atherosclerosis. To explore the effects of hyperglycemia on the maturation and immune function of human monocyte derived dendritic cells (MDCs).

METHODSImmature MDCs were cultured in RPMI1640 medium with either 5.5 mmol/L D-glucose (NG), 25 mmol/L D-glucose (HG) or 5.5 mmol/L D-glucose + 19.5 mmol/L mannitol (HM) in the absence or presence of 30 mmol/L N-acetylcysteine [NAC, a reactive oxygen species inhibitor (ROS)] for 48 hours. FACS was used to investigate the MDCs immunophenotypic expression. Immune function was evaluated by allogeneic mixed T lymphocyte reaction and measurement of cytokine levels from culture supernatants. Intracellular ROS production in MDCs was also measured by 2', 7'-dichlorodihydrofluorescein (DCF, 10 micromol/L) fluorescence using confocal laser-scanning microscopy techniques.

RESULTSCompared with NG and HM treated MDCs, the expression of maturation markers such as CD1a, HLA-DR, CD83, CD86 were significantly upregulated, allogeneic T cells proliferation as well as the cytokines secretions (IL-2, IL-12, IL-10 and IFN-gamma) significantly increased in HG treated MDCs. Intracellular ROS production in MDCs was also significantly increased and all these stimulatory effects of HG could be partially attenuated by NAC.

CONCLUSIONHigh glucose promote the maturation of MDCs and augment their capacity to stimulate T-cell proliferation and cytokine secretions at least in part through enhancing intracellular ROS generation. These stimulating effects of high glucose on MDCs maturation may be one of the mechanisms of accelerated atherosclerosis found in patients with diabetes.

Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Culture Media ; Cytokines ; biosynthesis ; Dendritic Cells ; drug effects ; immunology ; metabolism ; Glucose ; adverse effects ; pharmacology ; Humans ; Immunophenotyping ; Monocytes ; cytology ; Reactive Oxygen Species ; metabolism ; T-Lymphocytes ; cytology

OBJECTIVETo investigate the effects of asymmetric dimethylarginine (ADMA) on ACAT-1 expression and cholesterol content in THP-1-derived macrophages and foam cells.

METHODSTHP-1 cells were induced to differentiate into macrophages and further into foam cells. The macrophages and foam cells were exposed to different concentrations (0, 3.75, 7.5, 15, and 30 µmol/L) of ADMA for varying time lengths (6, 12, and 24 h), and the changes in ACAT-1 mRNA and protein levels in the cells were measured with RT-PCR and Western blotting. The cellular cholesterol content was measured with enzyme-linked colorimetry assay.

RESULTSIn THP-1-derived macrophages and foam cells, the expression levels of ACAT-1 mRNA and protein and cellular cholesterol content increased significantly in response to ADMA treatment in a time- and concentration-dependent manner.

CONCLUSIONADMA may play an important role in inducing foam cell formation from macrophages. ACAT-1 inhibition targeting the macrophages and foam cells may serve as a potential therapeutic target in the treatment of atherosclerosis.

Acetyl-CoA C-Acetyltransferase ; metabolism ; Arginine ; analogs & derivatives ; pharmacology ; Cell Line ; Cholesterol ; analysis ; Foam Cells ; cytology ; metabolism ; Humans ; Macrophages ; cytology ; drug effects ; metabolism ; Monocytes ; cytology ; drug effects ; RNA, Messenger ; genetics ; Up-Regulation

Crocetin, a naturally occurring carotenoid, possesses antioxidant and antiatherosclerotic properties, of which the underlying mechanism remains unclear. In the present study, we examined the effects of crocetin (0.1, 1, 10 μmol·L(-1)) on angiotensin II (Ang II, 0.1 μmol·L(-1)) induced expression of vascular cell adhesion molecule-1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs) and monocyte-endothelial cell adhesion. The effects of crocetin on the activation of nuclear factor kappa B (NF-κB) and intracellular reactive oxygen species (ROS) were also observed. The results demonstrated that crocetin notably suppressed Ang II induced NF-κB activation (P<0.01) and VCAM-1 expression (P<0.05, P<0.01) in HUVECs, accompanied by a markedly reduced monocyte-endothelial cell adhesion (P<0.05, P<0.01). In addition, preincubation with crocetin resulted in a significant enhancement of cellular antioxidant capacity (P<0.05, P<0.01), while Ang II induced intracellular ROS decreased markedly (P<0.05, P<0.01). These results indicated that crocetin was capable of suppressing Ang II induced VCAM-1 expression and monocyte-endothelial cell adhesion by suppression of NF-κB activation, which might be derived from the enhancement of antioxidant capacity and subsequent reduction of intracellular ROS.
Angiotensin II ; metabolism ; Antioxidants ; pharmacology ; Carotenoids ; pharmacology ; Cell Adhesion ; drug effects ; Human Umbilical Vein Endothelial Cells ; cytology ; drug effects ; metabolism ; Humans ; Monocytes ; cytology ; NF-kappa B ; metabolism ; Reactive Oxygen Species ; metabolism ; Vascular Cell Adhesion Molecule-1 ; metabolism

OBJECTIVETo investigate the effects of benzene poisoning on the expression of multidrug resistance 1 (MDR1) gene and P-glycoprotein (P-gp) in the bone marrow mononuclear cells (BMMNCs) of C57BL/6 mice.

METHODSC57BL/6 mice were randomly divided into control group (n = 24), low-dose group (n = 24), medium-dose group (n = 24), and high-dose group (n = 24) to receive corn oil, 25 mg/kg benzene, 50 mg/kg benzene, or 100 mg/kg benzene by gavage, once daily, 5 days/weeks, for 4 weeks. The mice were sacrificed on day 12, 26, or 29 of poisoning. Peripheral blood routine test was performed; real-time quantitative PCR was used to measure the MDR1 gene expression in BMMNCs; Western blot was used to measure the P-gp expression in BMMNCs.

RESULTSOn day 12, the red blood cell count and hemoglobin level in the high-dose group were significantly lower than those in the control group, low-dose group, and medium-dose group (P < 0.01 or P < 0.05). On day 26, the white blood cell count in the high-dose group was significantly lower than those in the control group, low-dose group, and medium-dose group (P < 0.01 or P < 0.05). At each time point, the mRNA expression of MDR1 gene in the low-dose group, medium-dose group, and high-dose group was significantly lower than that in the control group (P < 0.01). On day 26, the P-gp expression in the high-dose group was significantly lower than those in the control group, low-dose group, and medium-dose group, and the P-gp expression in the medium-dose group was significantly lower than that in the low-dose group (P < 0.01 or P < 0.05). On day 29, the P-gp expression in the low-dose group, medium-dose group, and high-dose group was significantly lower than that in the control group (P < 0.05).

CONCLUSIONBenzene poisoning can affect the expression of MDR1 gene and P-gp, which may be one of the mechanisms of benzene hematotoxicity.

ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Animals ; Benzene ; toxicity ; Bone Marrow Cells ; cytology ; drug effects ; metabolism ; Drug Resistance, Multiple ; genetics ; Male ; Mice ; Mice, Inbred C57BL ; Monocytes ; cytology ; drug effects ; metabolism

OBJECTIVETo investigate the effects of atorvastatin on expressions of scavenger receptor A and secretion of monocyte chemoattractant protein-1 (MCP-1) in foam cells.

METHODSTHP-1 cells were induced to differentiate into macrophages by PMA and treated with 0.1% BSA (control), ox-LDL (100 mg/L) or ox-LDL plus atorvastatin (5, 10, 20 micromol/L) for 24 hours. MCP-1 concentration in cell substratum was measured by ELISA. Scavenger receptor A expression was observed under fluorescent microscope after incubated with DiI-Ac-LDL. The relationship between concentration of MCP-1 and the activity of scavenger receptor A was also analyzed.

RESULTSCompared to the control cells, MCP-1 concentration in ox-LDL treated cells was significantly increased after 6 hours, peaked at 12 hours and was still significantly increased after 24 hours (all P < 0.05 vs. baseline). The activity of scavenger receptor A was also significantly increased in ox-LDL treated cells (P < 0.01 vs. control). The activity of scavenger receptor A proteins correlated positively to the concentration of MCP-1 in ox-LDL treated cells (r = 0.683, P < 0.01). Atorvastatin significantly attenuated these changes in a dose-dependent manner.

CONCLUSIONSScavenger receptor A and MCP-1 expressions were significantly increased in the course of monocyte lines THP-1 differentiating into macrophages and foam cells. The anti-atherosclerosis effect of atorvastatin might be partly achieved by inhibiting the secretion of MCP-1 and expression of scavenger receptor A in foam cells.

Atorvastatin Calcium ; Cell Differentiation ; Cell Line ; Chemokine CCL2 ; metabolism ; Foam Cells ; cytology ; drug effects ; metabolism ; Heptanoic Acids ; pharmacology ; Humans ; Monocytes ; cytology ; drug effects ; metabolism ; Pyrroles ; pharmacology ; Scavenger Receptors, Class A ; metabolism