PURPOSE: To investigate the production of long pentraxin 3 (PTX3) in response to tunicamycin-induced endoplasmic reticulum (ER) stress and its role in ER stress-associated cell death, PTX3 expression was evaluated in the human retinal pigment epithelial cell line, ARPE-19. METHODS: PTX3 production in ARPE-19 cells was analyzed in the absence or presence of tunicamycin treatment by enzyme-linked immunosorbent assay. PTX3 protein and mRNA levels were estimated using western blot analysis and real-time reverse transcription-polymerase chain reaction, respectively. Protein and mRNA levels of CCAAT-enhancer-binding protein homologous protein (CHOP) and ARPE-19 cell viability were measured in the presence of tunicamycin-induced ER stress in control or PTX3 small hairpin RNA (shRNA)-transfected ARPE-19 cells. RESULTS: The protein and mRNA levels of PTX3 were found to be significantly increased by tunicamycin treatment. PTX3 production was significantly decreased in inositol-requiring enzyme 1α shRNA-transfected ARPE-19 cells compared to control shRNA-transfected cells. Furthermore, pretreatment with the NF-κB inhibitor abolished tunicamycin-induced PTX3 production. Decreased cell viability and prolonged protein and mRNA expression of CHOP were observed under tunicamycin-induced ER stress in PTX3 shRNA transfected ARPE-19 cells. CONCLUSIONS: These results suggest that PTX3 production increased in the presence of tunicamycin-induced ER stress. Therefore, PTX3 could be an important protector of ER stress-induced cell death in human retinal pigment epithelial cells. Inositol-requiring enzyme 1α and the NF-κB signaling pathway may serve as potential targets for regulation of PTX3 expression in the retina. Therefore, their role in PTX3 expression needs to be further investigated.
Anti-Bacterial Agents/pharmacology ; Apoptosis ; Blotting, Western ; C-Reactive Protein/biosynthesis/*genetics ; Cells, Cultured ; Endoplasmic Reticulum Stress/*drug effects/genetics ; Enzyme-Linked Immunosorbent Assay ; *Gene Expression Regulation ; Humans ; Polymerase Chain Reaction ; RNA, Messenger/*genetics ; Retinal Pigment Epithelium/*metabolism/pathology ; Serum Amyloid P-Component/biosynthesis/*genetics ; Tunicamycin/*pharmacology

The activation of nuclear factor of activated T cells 5 (NFAT5), a well-known osmoprotective factor, can be induced by isotonic stimuli, such as activated Toll-like receptors (TLRs). It is unclear, however, how NFAT5 discriminates between isotonic and hypertonic stimuli. In this study we identified a novel context-dependent suppression of NFAT5 target gene expression in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS) or a high salt (NaCl) concentration. Although LPS and NaCl both used NFAT5 as a core transcription factor, these stimuli mutually inhibited distinct sets of NFAT5 targets within the cells. Although reactive oxygen species (ROS) are essential for this inhibition, the source of ROS differed depending on the context: mitochondria for high salt and xanthine oxidase for TLRs. Specifically, the high salt-induced suppression of interleukin-6 (IL-6) production was mediated through the ROS-induced inhibition of NFAT5 binding to the IL-6 promoter. The context-dependent inhibition of NFAT5 target gene expression was also confirmed in mouse spleen and kidney tissues that were cotreated with LPS and high salt. Taken together, our data suggest that ROS function as molecular sensors to discriminate between TLR ligation and osmotic stimuli in RAW 264.7 macrophages, directing NFAT5 activity toward proinflammatory or hypertonic responses in a context-dependent manner.
Animals ; *Gene Expression Regulation/drug effects ; Interleukin-6/biosynthesis/genetics ; Lipopolysaccharides/pharmacology ; Macrophages/drug effects/metabolism ; Male ; Mannitol/pharmacology ; Mice ; Mice, Inbred BALB C ; NF-kappa B/metabolism ; Promoter Regions, Genetic/genetics ; Protein Binding/drug effects/genetics ; Reactive Oxygen Species/*metabolism ; Rotenone/pharmacology ; Sodium Chloride/pharmacology ; Toll-Like Receptors ; Transcription Factors/genetics/*metabolism

We investigated acute effects of intermittent large dose bisphophonate therapy in osteoporotic patients. Peripheral blood mononuclear cells were incubated with alendronate (100 micrometer) for 18 hr, in vitro and cytokine expressions were measured by real-time RT-PCR. Pamidronate 30 mg was administered on 26 osteoporotic patients; and acute phase reactants, inflammatory cytokines and bone biomarkers were measured. The in vitro study showed significant increase in mRNA expression of IL-6, TNF-alpha and IFN-gamma. A notable rise in serum C-reactive protein (CRP) was observed over 3 days after pamidronate infusion (P=0.026). Serum levels of TNF-alpha, IL-6 and IFN-gamma were also significantly increased (P=0.009, 0.014, 0.035, respectively) and the increase in IL-6 levels were strongly correlated with CRP levels (P=0.04). Serum calcium and c-telopeptide levels rapidly decreased after the treatment (P=0.02, <0.001, respectively). This study showed that mRNA expression of inflammatory cytokines at peripheral blood mononuclear cells (PBMC) level were observed within 18 hr and marked elevation of inflammatory cytokines and acute phase reactants were demonstrated after pamidronate infusion at the dose for osteoporosis. Our studies confirmed that intermittent large dose aminobisphosphonate causes acute inflammation.
Acute-Phase Proteins/biosynthesis/genetics ; Adult ; Aged ; Aged, 80 and over ; Alendronate/pharmacology ; Biological Markers/blood ; Blood Cells/drug effects ; Bone Density Conservation Agents/*administration & dosage ; C-Reactive Protein/genetics/metabolism ; Calcium/blood ; Collagen Type I/blood ; Diphosphonates/*administration & dosage ; Female ; Humans ; Injections, Intravenous ; Interferon-gamma/blood/genetics ; Interleukin-6/blood/genetics ; Male ; Middle Aged ; Osteoporosis/*drug therapy ; Peptides/blood ; RNA, Messenger/metabolism ; Tumor Necrosis Factor-alpha/genetics/metabolism

Angioplasty, Balloon, Coronary ; C-Reactive Protein ; analysis ; Coronary Restenosis ; prevention & control ; Drug-Eluting Stents ; Humans ; Inflammation ; complications ; etiology ; prevention & control ; Interferon-gamma ; blood ; Interleukin-6 ; blood ; Muscle, Smooth, Vascular ; immunology ; Sirolimus ; administration & dosage ; Tumor Necrosis Factor-alpha ; biosynthesis ; blood ; Tunica Intima ; pathology

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

OBJECTIVETo investigate the role of reactive oxygen species (ROS) and ROS-caused mitochondrial transmembrane potential loss in sodium selenite-induced apoptosis in NB4 cells.

METHODSROS production was measured by ROS-specific probe DCFH-DA. Sodium selenite mitochondrial transmembrane potential loss was evaluated by flow cytometry with Rh123 staining. Protein levels of cytochrome C, Bid, Bcl-xl, and Bax were measured by Western blot using protein-specific antibodies. NB4 cells were pre-incubated by MnTmPy or BSO before selenite treatment to further confirm the effects of ROS on NB4 cells.

RESULTS20 micromol/L sodium selenite induced ROS production and mitochondrial transmembrane potential loss in NB4 cells time-dependently. Cytochrome C accumulated in cytoplasm after selenite treatment. Sodium selenite also downregulated Bcl-xl and activated Bax and Bid at protein level. Pretreatment with antioxidant MnTmPy almost fully abrogated the proapoptotic effect of sodium selenite prevented the cleavage of Bid protein and in turn the mitochondrail transmembrane potential loss. On the contrary, pretreatment with BSO intensified the mitochondrail transmembrane potential loss induced by sodium selenite.

CONCLUSIONSSodium selenite may induce apoptosis by inducing ROS production in NB4 cells, which leads to the downregulation of Bcl-xl, upregulation of Bax, and cleavage and activation of Bid. Bax and tBid then agregate on mitochondrial membrane, which in turn causes a decrease of mitochondrial transmembrane potential and release of cytochrome C into cytoplasm.

Apoptosis ; BH3 Interacting Domain Death Agonist Protein ; biosynthesis ; Cell Line, Tumor ; Cytochromes c ; metabolism ; Humans ; Membrane Potential, Mitochondrial ; drug effects ; Reactive Oxygen Species ; metabolism ; Sodium Selenite ; pharmacology ; bcl-2-Associated X Protein ; biosynthesis ; bcl-X Protein ; biosynthesis

OBJECTIVEIn the present study, we examined the expression changes of Bcl-2/Bax in C-reactive protein (CRP) treated human endothelium cells in vitro.

METHODSThe human umbilical vein endothelial cells (HUVEC) were cultured by digest method for 2 - 3 posterities and incubated with human CRP (0, 1, 5, 25 mg/L for 24 hours) and analyzed by flow cytometer for apoptosis ratio. The effects of CRP in various concentrations on Bcl-2/Bax mRNA and protein expression were examined by RT-PCR and Western Blotting.

RESULTSApoptosis ratio increased, downregulated Bcl-2 (gene promoting cell survival) and upregulated Bax (gene promoting apoptosis) at mRNA and protein levels in proportion to increased CRP concentrations.

CONCLUSIONThese results demonstrate that Bcl-2/Bax could be regulated by CRP in human HUVECs and might play a causal role in CRP-induced apoptosis.

Apoptosis ; drug effects ; C-Reactive Protein ; pharmacology ; Cell Line ; Endothelial Cells ; cytology ; metabolism ; Humans ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction ; Umbilical Veins ; cytology ; bcl-2-Associated X Protein ; biosynthesis

To study the molecular mechanisms of nitric oxide donor sodium nitroprusside (SNP) -induced apoptosis in K562 human leukemia cell line, the different concentrations of SNP and different time of culture were used to treat K562 cell. At the same time, potassium ferricyamide (PFC) was used as control, blank was designed in experiment. Cell apoptosis was analysed by cell morphology, DNA agarose gel electrophoresis, DNA content, and annexin-V/PI labeling method. The TdT-mediated dUTP nick end labeling (TUNEL) assay was used to quantify in situ cell apoptosis. Reactive oxygen species (ROS) in cells and mitochondrial transmembrane potential (DeltaPsim) were labeled by dihydrorhodamin 123, 2', 7'-dichlorodihydrofluorescein diacetate and rhodamin 123/PI. bcl-2, bax, bad, p53 gene proteins and mitochondrial membrane protein were analysed by flow cytometry. The results showed that the K562 cell apoptosis was confirmed by typical cell morphology, DNA fragment, sub-G(1) phase, TUNEL and annexin-V/PI labeling. A majority of K562 cells were arrested in G(0)/G(1) phase. During the process of SNP-induced apoptosis in K562 cell, the mean fluorescence intensity of ROS in cells was significantly higher than those in blank and PFC control, while the DeltaPsim reduced. The expression of p53, bax, bad, Fas protein and mitochondrial membrane protein increased and bcl-2 protein decreased after SNP treatment. It is concluded that SNP induces K562 cell apoptosis through increasing ROS in cells, expressing the p53, bax, bad, Fas protein and mitochondrial membrane protein and decreasing bcl-2 protein, opening the mitochondrial permeability transition pore and reducing DeltaPsim. Furthermore, the Fas was activated during the apoptosis process.
Apoptosis ; drug effects ; Dose-Response Relationship, Drug ; Humans ; In Situ Nick-End Labeling ; K562 Cells ; Membrane Potential, Mitochondrial ; drug effects ; Nitric Oxide Donors ; pharmacology ; Nitroprusside ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Reactive Oxygen Species ; metabolism ; Tumor Suppressor Protein p53 ; metabolism ; bcl-2-Associated X Protein ; metabolism ; fas Receptor ; biosynthesis

OBJECTIVETo investigate the effect of a tight control of blood glucose by intensive insulin therapy on human sepsis, and to explore the potential mechanism of the intensive insulin therapy.

METHODSEligible patients were randomized by a blinded pharmacist to receive tight control of blood glucose by intensive insulin therapy (maintenance of blood glucose at a level between 4.4 and 6.1 mmol/L) or to receive conventional treatment (maintenance of glucose at a level between 10.0 and 11.1 mmol/L). The expression of HLA-DR on peripheral monocytes was measured in 54 patients by flow cytometry on 24 h, 3 d, 5 d, 7 d, 10 d and 14 d of intensive care in parallel with serum c-reactive protein (CRP), severity of the disease (APACHE II score, SOFA score) and clinical data collection.

RESULTSPatients receiving intensive insulin therapy were less likely to require prolonged mechanical ventilation. Tight control of blood glucose significantly reduced the number of days during which leukopenia or leukocytosis and the days with hypo- or hyperthermia (P < 0.05). Hypoglycemia occurred in 3 patients (10.7%) in the tight control of blood glucose group. There were no instance of hemodynamic deterioration or convulsions. Compared with the conventional treatment, tight control of blood glucose also increased the HLA-DR expression of peripheral monocytes, and there were significantly difference on 3 d, 5 d and 7 d (P < 0.05). Whereas it suppressed the elevated serum CRP concentrations, there was significantly difference on 7 d (P < 0.05).

CONCLUSIONSTight control of blood glucose by intensive insulin therapy expedited healing of human sepsis, and increased the HLA-DR expression of peripheral and suppressed the elevated serum CRP. So, it is necessary to use insulin to strict control the glucose levels in human sepsis.

Blood Glucose ; metabolism ; C-Reactive Protein ; metabolism ; HLA-DR Antigens ; biosynthesis ; Humans ; Hyperglycemia ; drug therapy ; etiology ; metabolism ; Hypoglycemic Agents ; therapeutic use ; Insulin ; therapeutic use ; Sepsis ; complications

OBJECTIVE: To investigate the level of mRNA expression of C-reactive proteins (CRP) induced by LPS in human alveolar type epithelial cell line, A549. METHODS: Sputum and plasma specimens were obtained from patients with chronic obstructive pulmonary disease (COPD) diagnosed according to the national criteria. CRP was measured by enzyme-linked immunosorbent assays (ELISA). A549 cells were incubated with lipopolysaccharide (LPS) at different concentrations and for different time. CRP mRNA was extracted from cells and the expression was analyzed by RT-PCR. The CRP in the supernatant was measured by ELISA. RESULTS: The concentration of CRP in the sputum of patients with COPD was significantly higher than that in the plasma (P < 0.05). LPS at different concentrations and for different time induced the expression and secretion of CRP in A549 with a time-dependent increase and the expression of CRP were significantly higher than those of the control (P < 0.05 - 0.01). CONCLUSION Self-secretion of CRP in the respiratory tract may exist. A549 induced by LPS may express CRP mRNA.
C-Reactive Protein ; biosynthesis ; genetics ; metabolism ; Epithelial Cells ; cytology ; metabolism ; Female ; Humans ; Lipopolysaccharides ; Male ; Middle Aged ; Pulmonary Alveoli ; cytology ; metabolism ; Pulmonary Disease, Chronic Obstructive ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Sputum ; metabolism