Phospholipase D (PLD), one of the intracellular signal transduction enzymes, may play an important role in developing brain. However, the developmental regulation of PLD protein has not been determined. In the present study, we investigated the temporal and spatial expression of PLD isozyme, PLD1 in the developing rat forebrain using an affinity-purified peptide antibody against PLD1. Our data showed that immunoreactivity for PLD1 was first seen in the germinal zone of the lateral ventricle, differentiating neurons and their processes at embryonic day 18 (E18). At E20, clusters of immunoreactive cells were observed in the medial germinal zone of the lateral ventricle, restricted zones of the frontal and parietal cortex, the nuclei of the medial septum and the diagonal band. During the first postnatal week, there was an increase in the number and staining intensity of the immunoreactive neurons in the cerebral cortex, which peaked at postnatal day 7 (P7). During the second postnatal week, there was an abrupt decrease in the number of immunoreactive cortical pyramidal neurons. By P14, only a few of the pyramidal neurons in cerebral cortex layer V were immunoreactive. These results revealed that expression of PLD1 protein at various stages of development of the septum and cerebral cortex is differentially regulated. This suggests that PLD1 may regulate the developmental processes of some neuronal populations.
Animals ; Brain ; Cerebral Cortex ; Immunohistochemistry ; Lateral Ventricles ; Neurons ; Phospholipase D ; Phospholipases* ; Prosencephalon* ; Rabeprazole ; Rats* ; Signal Transduction

GTPrS-dependent phospholipase D activity in human neutrophils was investigated using exogenous phospholipid as a substrate. Both cytosolic and membrane- associated phospholipase D activities were identified. The previously described 50 kDa cytosolic activating factor was resolved chromatographically from the cytosolic phospholipase D. Using exogenous phospholipid as substrate along with chromatographically resolved 50 kDa factor and recombinant ADP-ribosylation factor 1, plasma membrane was required for activity, indicating that the activity which was previously seen using endogenous phospholipid substrate was due to a phospholipase D located in the plasma membrane. In addition, ADP-ribosylation factor and the 50 kDa factor activated synergistically. Using neutrophil plasma membranes, a third regulator of neutrophil membrane phospholipase D was identified from bovine brain cytosol. This factor was resolved from ADP-ribosylation factor and Rho A by successive column chromatographies. The brain factor showed a synergistic effect with the 50 kDa neutrophil activator but an additive effect with recombinant ADP- ribosylation factor. Whether or not ADP-ribosylation factor or the brain factor were present, high activities were seen only when the 50 kDa factor was present, indicating that the 50 kDa cytosolic factor is a major activating factor for the neutrophil plasma membrane phospholipase D.
ADP-Ribosylation Factor 1 ; ADP-Ribosylation Factors* ; Brain* ; Cell Membrane ; Chromatography ; Cytosol* ; Fibrinogen ; Humans ; Membranes ; Neutrophils* ; Phospholipase D* ; Phospholipases*

PURPOSE: Phospholipase D (PLD) catalyzes the hydrolytic cleavage of terminal phosphate diester bond of glycerophopholipids to produce phosphatidic acid (PA). PLD plays an important role in signal transduction and is known to be involved closely in cancer promotion, inflammation, and other cell responses. In order to evaluate radiation effect in tumor cells, various cells were screened for PLD activities and examined their radiation effects on PLD following gamma- ray irradiation. MATERIALS AND METHODS: PLD activities in 19 species of cell were measured by radioactive isotope method with 1,2 - di [1-14C] phosphatidylcholine in the presence of oleate. Among the cell lines examined, VERO 76, L 1210 and P 388 were selected and examined for their effects of metal ions and agonists on PLD activities before and after irradiation by Co-60 teletheraphy unit. RESULTS: The activities of oleate-PLD were observed in 11 species among 19 cell lines examined. VERO 76 and L 1210 cells showed that the PLD activity increased immediately after irradiation and reached to 150~200% of the control levels. The activation of PLD in response to gamma-ray was maximum at 20 Gy. In irradiated VERO 76, the stimulatory effect of Mg2+ was reduced and the activation of PLD by agonists in irradiated cells vary from those of the control cells. CONCLUSION: The activation effect of irradiation on PLD activity observed strongly implies that the PLD activity is closely related to the phenomena of cell necrosis. Therefore the cell lines examined here could provide a good source for the study of radiobiology that cover from cell death to cancer promotion.
Cell Death ; Cell Line* ; Inflammation ; Ions ; Necrosis ; Oleic Acid ; Phosphatidic Acids ; Phosphatidylcholines ; Phospholipase D ; Radiation Effects ; Radiobiology ; Signal Transduction

OBJECTIVES: Systemic lupus erythematosus (SLE) is a kind of autoimmune inflammatory connective tissue disease which seriously endangers human health. Genetic factors play a key role in the pathogenesis of SLE. This study aims to investigate a novel phospholipase D2 (PLD2) mutation associated with familial SLE, and further explore the underlying mechanism of the mutation in SLE. METHODS: The blood samples from a SLE patient, the patient's parents, and 147 normal controls were collected and DNA was extracted. Whole genome high-throughput sequencing was performed in the patient and her parents and the results were further analyzed by various bioinformatics methods. The wild type (wt), mutant type (mu), and negative control PLD2 plasmids were further constructed and transfected into 293 cells. The expression level of HRAS protein in 293 cells was detected by Western blotting. RESULTS: In this SLE family, the female SLE patient and her mother, 1 in generation II and 1 in generation III had typical clinical manifestations of SLE, and all of them had lupus nephritis at early stage. The genetic characteristics are consistent with autosomal dominant inheritance. A novel PLD2 heterozygous mutation (c.2722C>T) was found in the patient and her mother, but not in her father and other normal controls. Compared with wtPLD2 plasmid and negative control PLD2 plasmid, the expression of HRAS in 293 cells transfected with muPLD2 plasmid was significantly up-regulated (both CONCLUSIONS PLD2 c.2722C>T mutation may be one of the pathogeny of SLE in this family.
Case-Control Studies ; Female ; High-Throughput Nucleotide Sequencing ; Humans ; Lupus Erythematosus, Systemic/genetics* ; Lupus Nephritis ; Mutation ; Phospholipase D

BACKGROUND: Tumor invason and metastasis are the major causes of morbidity and death for cancer patients. Metastatic spread depends critically upon the invasiveness of the tumor cells, i.e., their ability to breach basement membrane by profusely secreting specific proteolytic enzymes such as MMP-2. TIMP-2 has a high affinity for progelatinase A and will form a 1:1 complex with either the latent or activated forms of the enzyme and has inhibitory activity against MMP-2. Laminin induced activation of Phospholipase D (PLD) and consequent generation of phosphatidic acid are involved in a signal propagation pathway leading to induction of MMP-2 in metastatic HT 1080 fibrosarcoma cells. We also studied a expression of PLD, MMP-2 and TIMP-2 in colorectal adenocarcinoma. METHODS: Colorectal adenocarcinomas from 13 patients in our hospital were studied for immunohistochemical expression of PLD, MMP-2, and TIMP-2 to assess their diagnostic and prognostic importance as well as relation between PLD and MMP-2. RESULTS: 1) Expression of PLD-2 was detected in 77% of the cases in colorectal adenocarcinomas. 2) MMP-2 expression was significantly associated with the presence of lymph-node metastasis, with moderated to strong expression present in 100% of the cases compared with 28.6% of the non-metastatic cases (P-value=0.017). 3) For colorectal adenocarcinomas, a strong correlation between PLD and MMP-2 expression was detected (P-value=0.008). CONCLUSION: PLD-2 can be used as a potential marker for malignant disease in colorectal adenocarcinomas. MMP-2 expression was significantly associated with the presence of lymph-nodemetastasis. A strong correlation between PLD and MMP-2 expression was also detected in colorectal carcinoma.
Adenocarcinoma ; Basement Membrane ; Colorectal Neoplasms* ; Fibrosarcoma ; Humans* ; Laminin ; Neoplasm Metastasis ; Peptide Hydrolases ; Phosphatidic Acids ; Phospholipase D* ; Phospholipases* ; Tissue Inhibitor of Metalloproteinase-2*

Lysophosphatidylcholine (LPC) is a bioactive lipid generated by phospholipase A2-mediated hydrolysis of phosphatidylcholine. In the present study, we demonstrate that LPC stimulates phospholipase D2 (PLD2) activity in rat pheochromocytoma PC12 cells. Serum deprivation induced cell death of PC12 cells, as demonstrated by decreased viability, DNA fragmentation, and increased sub-G1 fraction of cell cycle. LPC treatment protected PC12 cells partially from the cell death and induced neurite outgrowth of the cells. Overexpression of PLD2 drastically enhanced the LPC-induced inhibition of apoptosis and neuritogenesis. Pretreatment of the cells with 1-butanol, a PLD inhibitor, completely abrogated the LPC-induced inhibition of apoptosis and neurite outgrowth in PC12 cells overexpressing PLD2. These results indicate that LPC possesses the neurotrophic effects, such as anti-apoptosis and neurite outgrowth, through activation of PLD2.
Starvation ; Rats ; Phospholipase D/antagonists & inhibitors/*metabolism ; PC12 Cells ; Neurites/*drug effects ; Lysophosphatidylcholines/*pharmacology ; Cell Survival/drug effects ; Apoptosis/*drug effects ; Animals

STATEMENT OF PROBLEM: To improve a direct implant fixation to the bone, various strategies have been developed focusing on the surface of materials. The surface quality of the implant depends on the chemical, physical, mechanical and topographical properties of the surface. The different properties will interact with each other and a change in thickness of the oxide layer may also result in a change in surface energy, the surface topography and surface, chemical composition. However, there is limited the comprehensive study with regard to changed surface and biologic behavior of osteoblast by anodization. PURPOSE OF STUDY: The aim of this study was to analyze the characteristics of an oxide layer formed and to evaluate the cellular biologic behaviors on titanium by anodic oxidation (anodization) by cellular proliferation, differentiation, ECM formation and gene expression. And the phospholipase activity was measured on the anodized surface as preliminary study to understand how surface properties of Ti implant are transduced into downstream cellular events. METHODS AND MATERIALS: The surface of a commercially pure titanium(Grade 2) was modified by anodic oxidation. The group 1 samples had a machined surface and other three experimental specimens were anodized under a constant voltage of 270 V(Group 2), 350 V(Group 3), and 450 V(Group 4). The specimen characteristics were inspected using the following five categories; the surface morphology, the surface roughness, the thickness of oxide layer, the crystallinity, and the chemical composition of the oxide layer. Cell numbers were taken as a marker for cell proliferation. While the expression of alkaline phosphatase and Runx2 (Cbfa1) was used as early differentiation marker for osteoblast. The type I collagen production was determined, which constitutes the main structural protein of the extracellular matrix. Phospholipase A2 and D activity were detected. Results. (1) The anodized titanium had a porous oxide layer, and there was increase in both the size and number of pores with increasing anodizing voltage. (2) With increasing voltage, the surface roughness and thickness of the oxide film increased significantly (p<0.01), the TiO2 phase changed from anatase to rutile. During the anodic oxidization, Ca and P ions were more incorporated into the oxide layer. (3) The in vitro cell responses of the specimen were also dependant on the oxidation conditions. With increasing voltage, the ALP activity, type I collagen production, and Cbfa 1 gene expression increased significantly (p<0.01), while the cell proliferation decreased. (4) In preliminary study on the relation of surface property and phospholipase, PLD activity was increased but PLA2 activity did not changed according to applied voltage. CONCLUSION: The anodized titanium shows improved surface characteristics than the machined titanium. The surface properties acquired by anodization appear to give rise more mature osteoblast characteristics and might result in increased bone growth, and contribute to the achievement of a tight fixation. The precise mechanism of suface property signaling is not known, may be related to phospholipase D.
Alkaline Phosphatase ; Bone Development ; Cell Count ; Cell Proliferation ; Collagen Type I ; Crystallins ; Extracellular Matrix ; Gene Expression ; Ions ; Osteoblasts ; Phospholipase D ; Phospholipases ; Phospholipases A2 ; Surface Properties ; Titanium*

OBJECTIVETo investigate the relationship between phospholipase D (PLD) activation and neutrophil priming induced by cardiopulmonary bypass (CPB), and try to clarify whether CPB-induced systemic inflammatory response can be attenuated by inhibiting neutrophilic PLD activation.

METHODSNeutrophils were isolated from arterial blood of 8 patients undergoing valve replacement before operation and 30 min after initiation of CPB respectively. Both the preoperative and CPB-stirred neutrophils were subdivided into 5 groups by receiving different experimental interventions: (1) bacterial lipopolysaccharide (LPS, 10 ng x ml(-1)), (2) N-formylmethionylphenylalanine (fMLP, 1 micromol x L(-1)), (3) LPS+fMLP, (4) 1-butanol (0.5%)+LPS+fMLP, (5) vehicle. Elastase and myeloperoxidase (MPO) release was measured for the parameters of neutrophil activation, neutrophil PLD activity was determined by quantitation of choline produced from the stable product of phosphatidylcholine catalyzed by PLD.

RESULTS(1) Preoperative neutrophils treated with LPS+fMLP presented significantly higher PLD activity (13.48+/-2.61 nmol choline x h(-1) x mg(-1)) and released more elastase and MPO than cells treated with vehicle (PLD activity 3.70+/-0.49 nmol choline x h(-1) x mg(-1)), P<0.01), LPS (P<0.01) and fMLP respectively. In 1-butanol+LPS+fMLP group, PLD activity of preoperative neutrophils was lower than that in LPS+fMLP group (P<0.01), besides the release of elastase and MPO decreased sharply below both LPS+fMLP and fMLP groups (P<0.01). In LPS group, PLD activity was higher (P<0.01), while elastase and MPO release did not differ from control. fMLP group presented PLD activity, elastase and MPO release higher than control (P<0.01); nevertheless, lower than LPS+fMLP group (P<0.01). (2) CPB-stirred neutrophils presented prominent PLD activity increment, and even the control level was 3.59-fold of the pre-operative control (P<0.01). PLD activity in LPS+fMLP group was higher than that in other groups. Notably, PLD activity was even nonstatistically lower in 1-butanol+LPS+fMLP group than that in LPS or fMLP group. CPB-stirred neutrophils in LPS+fMLP group released more elastase and MPO than control, LPS, and 1-butanol+LPS+fMLP groups did (P<0.01); however, neither of the release was statistically different from that of fMLP group.

CONCLUSIONSCardiopulmonary bypass enables neutrophil priming accompanied with significant increase in PLD activity. Inhibition of neutrophil PLD activation attenuates its priming and may alleviate CPB-induced systemic inflammatory reaction.

Adolescent ; Adult ; Cardiopulmonary Bypass ; adverse effects ; Female ; Humans ; Male ; Middle Aged ; Neutrophil Activation ; physiology ; Phospholipase D ; pharmacology ; Systemic Inflammatory Response Syndrome ; etiology ; physiopathology

BACKGROUND: GH3 cells are a well characterized and widely used model used for the in vitro study of growth hormone (GH) secretion. Thyrotropin releasing hormone (TRH) binds to receptors belonging to the family of G protein-coupled receptors, and secrets both GH & prolactin. Phospholipase D (PLD) is an enzyme that hydrolyses phosphatidylcholine to yield phosphatidic acid and choline, and plays important roles in cellular proliferation and hormonal secretion. To elucidate the pathway of the action of TRH in GH3 cells, we investigated the activities of PLC and PLD in GH3 cells treated with TRH or phorbor 12-myristate 13-acetate (PMA). METHODS: GH3 cells were labeled with [3H] myristate, followed by incubation of with 0.3% ethanol, prior to before the addition of the agonists. The total lipids were extracted from the harvested cells following treatment with the agonists. The PLD activity was assessed by measuring [3H] phosphatidylethanol from the [3H] phospholipid using thin layer chromatography. RESULTS: TRH (1 muM) stimulated the PLC activity by 44-fold over that of the control values. TRH (1 microM), mastoparan (5 muM), and PMA (500 muM) for 30 minutes increased PLD activity by 1.9, 1.5 and 2.2 fold, respectively, in comparison to the controls. The PLD activities after 15, 30, 60, 120 and 240 min treatments of TRH (1 microM) were 142%, 170%, 172%, 160% and 115%, respectively. CONCLUSION: These results suggest that TRH stimulates not only the PLC activity, but also the PLD activity in GH3 cells.
Cell Proliferation ; Choline ; Chromatography, Thin Layer ; Ethanol ; Growth Hormone ; Humans ; Myristic Acid ; Phosphatidic Acids ; Phosphatidylcholines ; Phospholipase D* ; Phospholipases* ; Prolactin ; Thyrotropin-Releasing Hormone

BACKGROUND AND OBJECTIVES: The aim of this study was to determine the effect of ethanol on the regulation of vascular tone. MATERIAL AND METHODS: Using rat aorta ring, isometric contraction and 45Ca uptake were measured. Phorbol 12,13-dibutyrate (PDBu), phenylephrine, KCl were used for the regulation of smooth muscle tone. RESULTS: Ethanol induced transient contraction in rat aorta ring by dose-dependent manner. Ethanol suppressed the dose dependent contractile responses of vascular strip by phenylephrine, KCl and PDBu. Endothelium-dependent relaxation by acetylcholine was inhibited by ethanol. Ethanol depressed 45Ca uptake by high KCl but not by phenylephrine or PDBu in rat aorta. n-butanol selectively suppressed tonic contraction by high KCl, but t-butanol did not at the same concentration of butanol in rat aorta. PDBu-induced contraction was selectively suppressed by n-butanol but not by t-butanol. CONCLUSIONS: These findings suggest that the action of ethanol on phospholipase D is involved in the decreased response of rat aorta strip by vasoconstrictors.
1-Butanol ; Acetylcholine ; Animals ; Aorta* ; Ethanol* ; Isometric Contraction ; Muscle, Smooth* ; Phenylephrine ; Phorbol 12,13-Dibutyrate ; Phospholipase D ; Protein Kinase C ; Rats* ; Relaxation ; tert-Butyl Alcohol ; Vasoconstrictor Agents