Human secreted phospholipase A2 GIIE (hGIIE) is involved in inflammation and lipid metabolism due to its ability of hydrolyzing phospholipids. To reveal the mechanism of substrate head-group selectivity, we analyzed the effect of mutation of hGIIE on its activity and selectivity. hGIIE structural analysis showed that E54 might be related to its substrate head-group selectivity. According to the sequence alignment, E54 was mutated to alanine, phenylalanine, and lysine. Mutated genes were cloned and expressed in Pichia pastoris X33, and the enzymes with mutations were purified with 90% purity by ion exchange and molecular size exclusion chromatography. The enzymatic activities were determined by isothermal microthermal titration method. The Km of mutant E54K towards 1,2-dihexyl phosphate glycerol decreased by 0.39-fold compared with that of wild type hGIIE (WT), and the Km of E54F towards 1,2-dihexanoyl-sn-glycero-3-phosphocholine increased by 1.93-fold than that of WT. The affinity of mutant proteins with phospholipid substrate was significantly changed, indicating that E54 plays an important role in the substrate head-group selectivity of hGIIE.
Humans ; Kinetics ; Mutation ; Phospholipases A2, Secretory ; Phospholipids ; Saccharomycetales ; Substrate Specificity

Infantile neuroaxonal dystrophy (INAD) is a rare neurodegenerative disease. Two boys aged 3 years and 4 years and 2 months respectively, were admitted to the hospital due to delayed mental and motor development. There were no abnormalities at birth, and both children had low muscle strength and tension on admission. One child was not able to stand alone and had impaired vision. Electromyography showed neurogenic damage, and head MRI revealed cerebellar atrophy. High-throughput sequencing revealed compound heterozygous mutations in the PLA2G6 gene in the two children. The mutations (IVS11-1G>T and c.1984C>G) in one child were new mutations, and immunohistochemistry showed a reduction in the protein expression of PLAG6 in the muscular tissue of this child. INAD has the main clinical manifestations of psychomotor developmental regression and cerebellar atrophy. High-throughput sequencing can help with clinical diagnosis.
Child, Preschool ; Group VI Phospholipases A2 ; genetics ; Humans ; Magnetic Resonance Imaging ; Male ; Mutation ; Neuroaxonal Dystrophies ; genetics ; Neurodegenerative Diseases ; genetics

BACKGROUND: Fluoranthene (FR) is a common environmental pollutant that exists in a complex mixture with other polycyclic aromatic hydrocarbons (PAHs). We identified biomarkers for monitoring FR exposure and investigated the rescue effect of FR-induced cellular toxicity via aryl hydrocarbon receptor (AHR) antagonist activity in bone marrow derived mesenchymal stem cells (BM-MSCs).METHODS: Morphological changes, viability, and rescue effects of an AHR antagonist (CH223191) were examined in BM-MSCs after exposure to FR. Cytotoxic effects were assayed using the tetrazolium-based colorimetric assay. Apoptosis was measured by annexin V and propidium iodide dye-based flowcytometry assay, mitochondrial membrane potential assay, and nuclear DNA fragmentation assay. Molecular signaling pathways of apoptosis and autophagy were investigated using immunoblotting. Proteomics were performed in order to reveal the spectra of cellular damage and identify biomarkers for FR exposure.RESULTS: Exposing BM-MSCs to FR (IC₅₀=50 µM) induced cell death and morphological changes, while the AHR antagonist showed rescue effects. Autophagy was activated and mitochondrial membrane potential was decreased. Proteomic analysis identified 48 deregulated proteins (26 upregulated and 22 downregulated). Among them, annexin A6, pyruvate kinase, UDP-glucose dehydrogenase, and phospholipase A2 could be potential biomarkers for FR exposure.CONCLUSION: The exposure of BM-MSCs to FR induced remarkable alterations in cellular biology and the proteome, allowing for identification of novel biomarkers for FR exposure. Furthermore, AHR antagonists might be able to prevent cellular damage due to FR exposure.
Annexin A5 ; Annexin A6 ; Apoptosis ; Autophagy ; Biomarkers ; Bone Marrow ; Cell Death ; DNA Fragmentation ; Immunoblotting ; Membrane Potential, Mitochondrial ; Mesenchymal Stromal Cells ; Oxidoreductases ; Phospholipases A2 ; Polycyclic Hydrocarbons, Aromatic ; Propidium ; Proteome ; Proteomics ; Pyruvate Kinase ; Receptors, Aryl Hydrocarbon

BACKGROUND/AIMS: Several lines of evidence from epidemiologic and laboratory studies have shown that the consumption of Artemisia or green tea extracts (MPGT) is inversely associated with the risk of alcohol-induced damage and other chronic diseases. Supported by previous studies showing that the combined extract of Artemisia and green tea, MPGT, exerted significantly either antioxidative or anti-inflammatory actions against Helicobacter pylori-associated gastric diseases, it was hypothesized that MPGT can offer protection against alcoholic gastritis. METHODS: Ethanol was administered to induce gastric damage in Wistar rats, which had been pretreated with various doses of MPGT, to measure the rescuing action of a MPGT pretreatment against ethanol-induced gastric damage. In addition, the molecular mechanisms for the preventive effects were examined. RESULTS: The MPGT pretreatment (100, 300, and 500 mg/kg) alleviated the ethanol-induced gastric damage, which was evidenced by the significant decrease in calcium-dependent phospholipase A2, MAPKs, and NF-κB levels compared to ethanol alone. Furthermore, the MPGT pretreatment preserved 15-prostaglandin dehydrogenase, whereas cyclooxygenase-2 was decreased significantly. All of these biochemical changes led to the significant alleviation of alcohol-associated gastric mucosal damage. Ethanol significantly increased the TUNEL positivity in the stomach, but MPGT decreased the apoptotic index significantly, which was associated with significantly lower pathological scores of ethanol-induced mucosal ulcerations. The significant protective changes observed alcoholic gastritis with MPGT were related to the increased expression of cytoprotective genes, such as heat-shock protein (HSP)27, HSP60, and PDGF. CONCLUSIONS: The efficient anti-inflammatory, anti-apoptotic, and regenerative actions of MPGT make it a potential nutrient phytoceutical to rescue the stomach from alcoholic gastritis.
Alcoholics* ; Artemisia* ; Chronic Disease ; Cyclooxygenase 2 ; Ethanol ; Gastritis* ; Heat-Shock Proteins* ; Helicobacter ; HSP27 Heat-Shock Proteins* ; Humans ; In Situ Nick-End Labeling ; Oxidoreductases ; Phospholipases A2 ; Rats, Wistar ; Stomach ; Stomach Diseases ; Tea* ; Ulcer

α-Synuclein (α-Syn) has a critical role in microglia-mediated neuroinflammation, which leads to the development of Parkinson's disease (PD). Recent studies have shown that bee venom (BV) has beneficial effects on PD symptoms in human patients or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxin-induced PD mice. This study investigated whether treatment with BV-derived phospholipase A2 (bvPLA2) would improve the motor dysfunction and pathological features of PD in human A53T α-Syn mutant transgenic (A53T Tg) mice. The motor dysfunction of A53T Tg mice was assessed using the pole test. The levels of α-Syn, microglia and the M1/M2 phenotype in the spinal cord were evaluated by immunofluorescence. bvPLA2 treatment significantly ameliorated motor dysfunction in A53T Tg mice. In addition, bvPLA2 significantly reduced the expression of α-Syn, the activation and numbers of microglia, and the ratio of M1/M2 in A53T Tg mice. These results suggest that bvPLA2 could be a promising treatment option for PD.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; alpha-Synuclein* ; Animals ; Bee Venoms* ; Bees* ; Fluorescent Antibody Technique ; Humans ; Mice ; Mice, Transgenic* ; Microglia* ; Parkinson Disease* ; Phenotype ; Phospholipases A2* ; Phospholipases* ; Spinal Cord

OBJECTIVETo investigate the clinical symptoms and potential mutations in the PLA2G6 gene for a child with infantile neuroaxonal dystrophy.

METHODSClinical data of the patient was collected. The coding regions of PLA2G6 gene was subjected to Sanger sequencing using blood DNA from the patient and her parents.

RESULTSThe patient has presented with psychomotor regression and hypotonia, followed by development of tetraparesis. A novel homozygous mutation G68A in the PLA2G6 gene was found by DNA sequencing, while her parents were both heterozygous carriers.

CONCLUSIONThe psychomotor regression and tetraparesis of the patient was caused by infantile neuroaxonal dystrophy due to a novel homozygous mutation in the PLA2G6 gene, which was inherited from her parents.

Adult ; Base Sequence ; Brain ; diagnostic imaging ; Child, Preschool ; DNA Mutational Analysis ; Female ; Group VI Phospholipases A2 ; genetics ; Homozygote ; Humans ; Magnetic Resonance Imaging ; Male ; Molecular Sequence Data ; Mutation ; Neuroaxonal Dystrophies ; diagnostic imaging ; genetics ; Radiography

OBJECTIVETo observe the effects of Danlou Tablet (DT) on inflammatory reaction, and expressions of lipoprotein-associated phospholipase A2 (LP-PLA2), secretory phospholipase A2 (sPLA2), and to analyze potential mechanisms.

METHODSForty male Wistar rats were randomly and equally divided into five groups, i.e., the normal control group, the model group, the Western medicine (WM) group, the low dose DT group, the high dose DT group, 8 in each group. Rats in the normal control group were fed with basic forage for 12 successive weeks, while AS rat model was established in rats of the other four groups by feeding high fat and sugar forage plus intraperitoneal injection of vitamin D₃. Normal saline, atorvastatin calcium suspension (at the daily dose of 1.8 mg/kg), low dose DT suspension (at the daily dose of 450 mg/kg), and high dose DT suspension (at the daily dose of 900 mg/kg) were administered to rats in the model group, the WM group, the low dose DT group, the high dose DT group respectively by gastragavage for 8 successive weeks. The general condition of all rats was observed. Rats were sacrificed after gastric administration and their serum collected. Serum levels of lipids (TC, TG, HDL-C, LDL-C) and inflammatory factors [IL-6, TNF-α, monocyte chemoattractant protein 1 (MCP-1), oxidized low-density lipoprotein (ox-LDL), lipoprotein-associated phospholipase A2 (LP-PLA2), secretory phospholipase A2 (sPLA2)] were detected. Pathological changes of thoracic aorta were observed by HE staining. Protein and gene expressions of LP-PLA2 and sPLA2 in thoracic aorta were measured by Western blot and real-time fluorescent quantitative PCR respectively.

RESULTSCompared with the normal control group, rats in the model group were in low spirits and responded poorly. Typical atherosclerotic plaque could be seen in thoracic aorta of rats in the model group. Serum levels of TC, TG, LDL-C, IL-6, TNF-α, MCP-1, ox-LDL, LP-PLA2, and sPLA2 significantly increased (P < 0.05); protein and gene expressions of LP-PLA2 and sPLA2 in rat thoracic aorta increased (P < 0.05) in the model group. After 8 weeks of intervention, rats in 3 medication groups appeared active, and HE staining showed subsidence of plaque in rat thoracic aorta. Compared with the model group, serum levels of TC, TG, LDL-C, IL-6, TNF-α, MCP-1, ox-LDL, and LP-PLA2 decreased in 3 medication groups (P < 0.01, P < 0.05); serum sPLA2 level decreased, protein and mRNA expressions of LP-PLA2 and sPLA2 in rat thoracic aorta decreased in the WM group (P < 0.01, P < 0.05); protein and mRNA expressions of LP-PLA2 in rat thoracic aorta significantly decreased in the low dose DT group (P < 0.01, P < 0.05), and those of LP-PLA2 and sPLA2 decreased in the high dose DT group (P < 0.01, P < 0.05).

CONCLUSIONDT could fight against inflammatory reaction and AS possibly through inhibiting LP-PLA2 expression and reducing ox-LDL production.

1-Alkyl-2-acetylglycerophosphocholine Esterase ; blood ; Animals ; Aorta, Thoracic ; pathology ; Atherosclerosis ; drug therapy ; Chemokine CCL2 ; blood ; Drugs, Chinese Herbal ; pharmacology ; Inflammation ; drug therapy ; Interleukin-6 ; blood ; Lipids ; blood ; Lipoproteins, LDL ; blood ; Male ; Phospholipases A2 ; blood ; Plaque, Atherosclerotic ; Random Allocation ; Rats ; Rats, Wistar ; Tablets ; Tumor Necrosis Factor-alpha ; blood

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.
Animals ; Blotting, Western ; Cyclic AMP Response Element-Binding Protein ; Dinoprostone ; Female ; Mice ; Phospholipases A2, Cytosolic ; Pregnancy ; Prostaglandin-E Synthases ; Real-Time Polymerase Chain Reaction ; Secretin ; Stromal Cells ; Uterus

We fortuitously observed a human neutrophil intracellular free-calcium concentration ([Ca2+]i) increasing activity in the commercially available phosphodiesterase I (PDE I), which is actually dried crude venom of Crotalus atrox. As this activity was not observed with another commercially available pure PDE I, we tried to find out the causative molecule(s) present in 'crude' PDE, and identified Lys49-phospholipase A2 (Lys49-PLA2 or K49-PLA2), a catalytically inactive protein which belongs to the phospholipase A2 family, by activity-driven three HPLC (reverse phase, size exclusion, reverse phase) steps followed by SDS-PAGE and LC-MS/MS. K49-PLA2 induced Ca2+ infl ux in human neutrophils without any cytotoxic eff ect. Two calcium channel inhibitors, 2-aminoetoxydiphenyl borate (2-APB) (30 microM) and SKF-96365 (20 microM) signifi cantly inhibited K49-PLA2-induced [Ca2+]i increase. These results suggest that K49-PLA2 modulates [Ca2+]i in human neutrophils via 2-APB- and SKF-96365-sensitive calcium channels without causing membrane disruption.
Calcium Channels ; Chromatography, High Pressure Liquid ; Crotalus* ; Electrophoresis, Polyacrylamide Gel ; Humans* ; Membranes ; Neutrophils ; Phosphodiesterase I ; Phospholipases A2 ; S Phase ; Venoms*

PURPOSE: Dysregulated cysteinyl leukotriene (CysLT) synthesis is prominent in exercise-induced bronchoconstriction (EIB). Secreted phospholipase A2 (sPLA2) plays a key regulatory role in the biosynthesis of CysLTs. We previously found that serum leptin levels correlate with (EIB) in children with asthma. The aim of this study was to address the relationship between plasma sPLA2/leptin levels and EIB. METHODS: Sixty-seven prepubertal children between the ages of 6 and 10 years were included in the study. They were asthmatics with EIB (n=25), asthmatics without EIB (n=21), and healthy subjects (n=21). We measured the plasma sPLA2 and leptin levels. We also performed pulmonary function tests at baseline, after bronchodilator inhalation, and after exercise. RESULTS: The sPLA2 and leptin levels were significantly higher in asthmatics with EIB than in those without and control subjects. In addition, sPLA2 levels were significantly correlated with body mass index (Speraman correlation coefficient r=0.343, P=0.023) and leptin levels (partial correlation coefficient r=318, P=0.033). The maximum decrease in % forced expiratory volume in 1 second after exercise was significantly correlated with both PLA2 levels (r=0.301, P=0.041) and leptin levels (r=0.346, P=0.018). CONCLUSION: The sPLA2 and leptin levels were significantly higher in asthmatics with EIB than in asthmatics without EIB and control subjects. In addition, sPLA2 levels were significantly correlated with leptin levels and EIB in asthmatic children.
Asthma ; Body Mass Index ; Bronchoconstriction* ; Child* ; Forced Expiratory Volume ; Humans ; Inhalation ; Leptin* ; Phospholipases A2* ; Plasma* ; Respiratory Function Tests