ABSTRACT
Secretin, a gastrointestinal peptide, has been found to be expressed in mouse endometrial stromal cells (mESCs) during early pregnancy. In order to further investigate the function of secretin during embryo implantation, the expression levels of secretin, secretin receptor, cytosolic phospholipase A(cPLA) and membrane prostaglandin E synthase 1 (mPGEs-1) were detected in the mice uterus from day 4 to 8 of pregnancy by real-time PCR, ELISA and in situ hybridization. mESCs isolated and cultured from day 4 of pregnancy were transfected with secretin expression vectors or treated with H89, a PKA inhibitor. Then the expression levels of cPLA, mPGEs-1 and cAMP responsive element-binding protein (CREB) were detected by real-time PCR and Western blot. The concentration of prostaglandin E2 (PGE) in the supernatant was determined by ELISA. The result showed that secretin, cPLAand mPGEs-1 mRNA expression increased gradually in implantation sites from day 5 to day 7 of pregnancy with the same tendency. The secretin levels in serum were significantly higher on days 6, 7 and 8 of pregnancy than that on day 5 of pregnancy. The concentration of secretin was significantly higher in implantation sites on days 6, 7 than that in non-implantation site on day 5. Transfection of secretin expression vector promoted cPLA, p-cPLAand mPGEs-1 expressions in mESCs, but not PGElevel in the supernatant. H89 could effectively inhibit the expression of CREB, p-CREB, p-cPLAand cPLAinduced by secretin. The results showed that the increased secretin expression in mESCs during embryo implantation may promote p-cPLA, cPLAand mPGEs-1 expression, and the promotion may be through PKA signaling pathway.
Subject(s)
Animals , Female , Mice , Pregnancy , Blotting, Western , Cyclic AMP Response Element-Binding Protein , Dinoprostone , Phospholipases A2, Cytosolic , Prostaglandin-E Synthases , Real-Time Polymerase Chain Reaction , Secretin , Stromal Cells , UterusABSTRACT
The purpose of this study was to elucidate the mechanism of the airborne poultry dust (particulate matter, PM)-induced respiratory tract inflammation, a common symptom in agricultural respiratory diseases. The study was based on the hypothesis that poultry PM would induce the release of inflammatory cytokine interleukin-8 (IL-8) by respiratory epithelial cells under the upstream regulation by cytosolic phospholipase A2 (cPLA2) activation and subsequent formation of cyclooxygenase (COX)- and lipoxygenase (LOX)-catalyzed arachidonic acid (AA) metabolites (eicosanoids). Human lung epithelial cells (A549) in culture were treated with the poultry PM (0.1-1.0 mg) for different lengths of time, following which PLA2 activity, release of eicosanoids and secretion of IL-8 in cells were determined. Poultry PM (1.0 mg/ml) caused a significant activation of PLA2 in a time-dependent manner (15-60 min), which was significantly attenuated by the calcium-chelating agents, cPLA2-specific inhibitor (AACOCF3) and antioxidant (vitamin C) in A549 cells. Poultry PM also significantly induced the release of COX- and LOX-catalyzed eicosanoids (prostaglandins, thromboxane A2 and leukotrienes B4 and C4) and upstream activation of AA LOX in the cells. Poultry PM also significantly induced release of IL-8 by the cells in a dose- and time-dependent manner, which was significantly attenuated by the calcium chelating agents, antioxidants and COX- and LOX-specific inhibitors. The current study for the first time revealed that the poultry PM-induced IL-8 release from the respiratory epithelial cells was regulated upstream by reactive oxygen species, cPLA2-, COX- and LOX-derived eicosanoid lipid signal mediators.
Subject(s)
Agriculture , Animals , Antioxidants/pharmacology , Arachidonic Acid/metabolism , Arachidonic Acid/metabolism , Biocatalysis , Cell Line , Cytokines/metabolism , Dose-Response Relationship, Drug , Egtazic Acid/analogs & derivatives , Egtazic Acid/pharmacology , Eicosanoids/metabolism , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Humans , Inflammation/chemically induced , Inflammation/metabolism , Interleukin-8/metabolism , Lipoxygenases/metabolism , Particulate Matter/chemistry , Particulate Matter/pharmacology , Phospholipases A2, Cytosolic/antagonists & inhibitors , Phospholipases A2, Cytosolic/metabolism , Poultry , Prostaglandin-Endoperoxide Synthases/metabolism , Reactive Oxygen Species/metabolism , Respiratory Mucosa/cytology , Respiratory Mucosa/metabolism , Respiratory Mucosa/metabolism , Signal Transduction/drug effects , Solvents/chemistry , Time FactorsABSTRACT
BACKGROUND: According to the notion of the immunoregulatory functions of moxifloxacin (MFX), the effect of MFX on the neutrophilic respiratory burst in conjunction with the expression of cytosolic phospholipase A2 (cPLA2) was investigated. METHODS: The effects and possible mechanisms of MFX on neutrophilic respiratory burst in oleic acid (OA)-induced acutely injured rats lung and OA-stimulated, isolated murine neutrophils were probed, associated with the expression of cytosolic phospholipase A2 in vivo and in vitro. RESULTS: In the OA-induced acutely-injured lungs, neutrophils were accumulated, which was attenuated by MFX. The parameters denoting a neutrophilic respiratory burst, such as nitro blue tetrazolium reaction, cytochrome-c reduction, neutrophil aggregation, H2O2 production in neutrophils revealed increased neutrophilic respiratory burst by OA, and MFX decreased all of these parameters. In addition, the enhanced expression of cPLA2 in the lung and isolated murine neutrophils by OA were decreased by MFX. CONCLUSION: MFX suppresses the OA-induced neutrophilic respiratory burst by the suppression of cPLA2 in neutrophils.
Subject(s)
Animals , Rats , Aza Compounds , Cytosol , Lung , Neutrophils , Oleic Acid , Phospholipases , Phospholipases A2 , Phospholipases A2, Cytosolic , Quinolines , Respiratory BurstABSTRACT
<p><b>OBJECTIVE</b>To investigate the genetic association between the polymorphism of cytosolic phospholipase A2 (cPLA2) family genes and schizophrenia in the North Han Chinese.</p><p><b>METHODS</b>Method of polymerase chain reaction-based ligase detection reaction (PCR-LDR) was applied to genotype 10 single nucleotide polymorphisms (SNPs) of cPLA2 family genes among 201 pedigrees consisting of fathers, mothers and affected offsprings with schizophrenia. Haplotype relative risk (HRR) test, transmission disequilibrium test (TDT), haplotype transmission analysis and multiple locus analysis were conducted to analyze the genotyping data.</p><p><b>RESULTS</b>The genotypic frequency of cPLA2 gene did not deviate from Hardy-Weinberg equilibrium in both case and control groups. HRR and TDT showed that the 10 SNPs were not associated with schizophrenia (P > 0.05). Analysis for haplotype transmission showed that no haplotype systems was associated with schizophrenia (P > 0.05). Results from COA and COG tests showed a disease association for the rs2162886-rs1668589, rs891014-rs1668589 and rs2307279-rs7542180 combinations (chi2 = 6.913, P = 0.032; chi2 = 8.393, P = 0.015; chi2 = 8.447, P = 0.038).</p><p><b>CONCLUSION</b>Many loci in the cPLA2 family genes were associated with schizophrenic.</p>