Extensive monocyte recruitment is an early phenomenon associated with the development of atherosclerotic lesion. Although the molecular mechanisms are not completely understood, monocyte recruitment into these early lesions may involve changes in endothelial adhesion for monocyte, in which adhesion molecules expressed by endothelial cell play an active role. In vivo, the function of endothelial cells is not only affected by the chemical factors, but also by the mechanical factors. The purpose of this article was to investigate the induction of adhesion molecules expression by synergistic effects of Lysophosphatidylcholine (Lyso-PC) and shear stress in cultured human umbilical vein endothelial cells (HUVEC). The surface expression of ICAM-1, VCAM-1 and E-selectin on HUVEC induced by Lyso-PC(30 micrograms/ml) and shear stress(2.23, 4.20 dyne/cm2) were analyzed using flow cytometry. The results showed that: Compared with what were simultaneously exposed to shear stress and Lyso-PC, activating the cells with Lyso-PC prior to shear stress, or pre-conditioning the cells exposed shear stress prior to Lyso-PC incubation, a significantly higher expression of ICAM-1 and VCAM-1(P < 0.05) was resulted. HUVEC were exposed to shear stress and Lyso-PC at the same time or treated with each agonist alone, E-selectin expression was not significantly different from the control group. However, a sequential action of the two stimuli significantly increased E-selectin expression(P < 0.05). We concluded that: a sequential action of the shear stress and Lyso-PC induced an even greater expression of ICAM-1 and VCAM-1, thus it could be understood that the flows-hear stress in combination with endothelial activated by chemical factors may increase the ability of endothelial cells to recruit leukocytes even under the mechanical environment unfavorable for cell adhesion.
Cell Adhesion Molecules ; biosynthesis ; Cells, Cultured ; Endothelium, Vascular ; cytology ; drug effects ; metabolism ; Humans ; Lysophosphatidylcholines ; pharmacology ; Stress, Mechanical ; Umbilical Veins ; cytology

AIMTo observe the effect of LPC on the pacemaker current I(f) in ischemic myocardium and if the effect could be reversed by ISO.

METHODSBy using two microelectrode voltage clamp technique to measure and compare the amplitude of I(f) of ischemic myocardium in the presence of LPC and LPC add ISO.

RESULTSIschemia decreased the amplitude of I(f) at all membrane potential levels. Adding LPC 2 x 10(-5) mol/L to the ischemia-like solution, the amplitude of I(f) decreased further (n = 5, P < 0.05), it means that LPC aggravated the inhibitory effect of "ischemia" on the pacemaker activity. Adding LPC 2 x 10(-5) mol/L and ISO 1 x 10(-6) mol/L together to the ischemia-like solution, the amplitude of I(f) increased significantly at membrane potential -90 mV to - 120 mV (n = 8, P < 0.05) compared with ischemia condition, but still did not reach the levels before ischemia.

CONCLUSIONIn acute myocardial ischemia condition, toxic metabolite LPC accentuated its inhibitory effect on pacemaker current I(f), a local release and accumulation of catecholamine could not completely reverse their inhibitory effect.

Animals ; Isoproterenol ; metabolism ; Lysophosphatidylcholines ; pharmacology ; Membrane Potentials ; drug effects ; Microelectrodes ; Myocardial Ischemia ; metabolism ; physiopathology ; Myocardium ; Patch-Clamp Techniques ; Sheep

OBJECTIVETo investigate the protective effect of neferine against damages of endothelial cells induced by lysophos-phatidylcholine (LPC) and the relationship with asymmetric dimethylarginine (ADMA).

METHODThe human umbilical vein endothelial cells (HUVEC-12) were treated with LPC (10 mg x L(-1)) for 24 h to establish the model of endothelial cells damages; HUVECs were prior exposed to neferine (0.1, 1.0 or 10.0 micromol x L(-1) ) for 1 h, and then exposed to LPC in the presence of the neferine for 24 h. At the end of the experiment, the cultured medium was collected for measuring the concentration of nitric oxide (NO), aleic dialdehyde (MDA) as well as ADMA and the cells were collected for measuring the level of intracellular reactive oxygen species (ROS).

RESULTCompared with control group, exposure of endothelial cells to LPC (10 mg x L(-1)) for 24 h significantly increased the concentration of MDA and ADMA in the medium and the level of intracellular ROS and coinstantaneously significantly decreased the concentration of NO in the medium. Neferine (0.1, 1.0 or 10.0 micromol x L(-1)) significantly inhibited the elevated concentration of MDA, ADMA as well as the level of intracellular ROS and coinstantaneously significantly attenuated the decreased level of NO induced by LPC.

CONCLUSIONNeferine can protect the endothelial cells against damages induced by LPC and the protective effect is related to the decrease of the concentration of ADMA.

Arginine ; analogs & derivatives ; metabolism ; Benzylisoquinolines ; pharmacology ; Cell Line ; Endothelial Cells ; drug effects ; metabolism ; Humans ; Lysophosphatidylcholines ; pharmacology ; Malondialdehyde ; metabolism ; Nitric Oxide ; metabolism ; Reactive Oxygen Species ; metabolism

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

OBJECTIVETo discuss the effect of protein kinase C (PKC) on regulation of ecto-5'-nucleotidase activity by lysophosphatidylcholine(LPC) in human umbilical endothelial cells (HUVEC).

METHODSExperiments were conducted in HUVEC grown on dishes which were divided into 4 groups (n=15): (1) Control group in which only eAMP (5 micromol/L) was added; (2) LPC group in which HUVEC were incubated with LPC (10 micromol/L) before eAMP was added; (3) Chelerythrine group in which cells were pre-incubated with the PKC inhibitor chelerythrine (100 micromol/L) before LPC and eAMP were added; (4) alpha, beta-Methyladenosine-5'-Diphosphate (AOPCP) group in which cells were incubated with AOPCP (10 micromol/L) before eAMP was added. Etheno-adenosine production was detected at 15th, 30th, 45th min with high performance liquid chromatography(HPLC) respectively.

RESULTSComparing to the control group LPC significantly increased etheno-adenosine production at three time points respectively (P < 0.05). Furthermore, PKC inhibitor chelerythrine abolished this effect of LPC and the ethenoadenosine production at three time points were at the same level of control group (P > 0.05). CD73 inhibitor AOPCP significantly decreased the etheno-adenosine production compared to the other three groups (P < 0.01).

CONCLUSIONEcto-5'-nucleotidase can be modulated within minutes following exposure of HUVEC to LPC and this response may be mediated by PKC in HUVEC.

5'-Nucleotidase ; metabolism ; Cells, Cultured ; GPI-Linked Proteins ; metabolism ; Human Umbilical Vein Endothelial Cells ; cytology ; metabolism ; Humans ; Lysophosphatidylcholines ; pharmacology ; Protein Kinase C ; physiology ; Up-Regulation ; drug effects

OBJECTIVE: To investigate the effects of fenofibrate on the proliferation and apoptosis and endothelial nitric oxide synthase (eNOS) mRNA expression of cultured human umbilical vein endothelial cells (HUVECs) induced by lysophosphatidylcholine (LPC). METHODS: HUVECs were cultured in vitro. The study was designated to 5 groups according to fenofibrate concentration: control group, LPC group, LPC + low-concentration fenofibrate (10 micromol/L), LPC + middle-concentration fenofibrate (50 micromol/L), and LPC + high-concentration fenofibrate (100 micromol/L). The study was designated to 6 groups according to the intervention time: control group, LPC group, LPC + fenofibrate (50 micromol/L) 6 h, LPC + fenofibrate 12 h, LPC + fenofibrate 24 h, and LPC + fenofibrate 48 h. The proliferation and apoptosis of HUVECs were evaluated by MTT assay, flow cytometry and fluorescence microscopy, respectively. eNOS mRNA were assayed by real time-PCR. RESULTS: Compared with the control group, LPC could inhibit the proliferation and induce apoptosis, and downregulate eNOS mRNA expression and decrease NO production of HUVECs. Fenofibrate could increase the proliferation and decrease the apoptosis, and up-regulate eNOS mRNA expression and enhance NO production in HUVECs. CONCLUSION Fenofibrate could improve the proliferation and inhibit the apoptosis, and up-regulate eNOS mRNA expression of HUVECs induced by LPC, which may be responsible for fenofibrate to prevent and treat atherosclerosis.
Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Endothelium, Vascular ; cytology ; Fenofibrate ; pharmacology ; Humans ; Hypolipidemic Agents ; pharmacology ; Lysophosphatidylcholines ; pharmacology ; Nitric Oxide Synthase Type III ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Umbilical Veins ; cytology

AIMTo determine the effect of lysophosphatidylcholine (LPC) on the expression of vascular endothelial growth factor (VEGF) in human umbilical veins endothelial cell line (ECV304) and the inhibitory effect of 2, 3, 5, 4'-tetrahydroxystilbene-2-O-beta-D-glucoside (ST I) in vitro.

METHODSExposure to 2.5 mg x L(-1) LPC or LPC + ST I for 24 hours, VEGF protein was determined by enzyme-linked immunosorbent assay (ELISA). Meanwhile, VEGF mRNA expression in ECV304 was examined by in situ hybridization. VEGF165 mRNA was examined by RT-PCR and Realtime RT-PCR.

RESULTSLPC upregulated VEGF protein and VEGF mRNA expression in the ECV304 cells. ST I was shown to markedly inhibit the LPC-induced increase of VEGF protein and VEGF165 mRNA (P < 0.001).

CONCLUSIONLPC can induce a strong expression of VEGF in ECV304 cells and ST I can inhibit it.

Cells, Cultured ; Endothelial Cells ; metabolism ; Glucosides ; isolation & purification ; pharmacology ; Humans ; Lysophosphatidylcholines ; antagonists & inhibitors ; Plants, Medicinal ; chemistry ; Polygonum ; chemistry ; RNA, Messenger ; biosynthesis ; genetics ; Stilbenes ; isolation & purification ; pharmacology ; Umbilical Veins ; cytology ; Vascular Endothelial Growth Factor A ; biosynthesis ; genetics

OBJECTIVETo investigate the effect of fluvastatin on lysophosphatidylcholine (LPC)-induced ventricular arrhythmias and its mechanism.

METHODSTwenty male SD rats were randomly allocated into two equal groups, namely LPC treatment group and fluvastatin pretreatment group. Langendorff apparatus was used for cardiac perfusion ex vivo with 5 µmol/L LPC for 5 min followed by washing for 30 min in LPC treatment group, and in fluvastatin pretreatment group, a 30-min perfusion with 10 µmol/L fluvastatin was administered before LPC perfusion. The LPC-induced nonselective cation current (I(NSC)) in the ventricular myocytes was recorded using the whole-cell voltage-clamp method.

RESULTSFluvastatin significantly inhibited LPC-induced ventricular tachyarrhythmia/fibrillation and I(NSC). The small G-protein Rho inhibitor (C3) and Rho-kinase inhibitor (Y-27632) in the pipette solution also suppressed LPC-induced I(NSC).

CONCLUSIONFluvastatin offers cardiac protection against LPC by inhibiting LPC-induced I(NSC). LPC induces fatal arrhythmia via a Rho/Rho-kinase-mediated pathway.

Animals ; Arrhythmias, Cardiac ; chemically induced ; metabolism ; Drug Antagonism ; Fatty Acids, Monounsaturated ; pharmacology ; Indoles ; pharmacology ; Ion Channels ; drug effects ; Lysophosphatidylcholines ; adverse effects ; Male ; Myocytes, Cardiac ; metabolism ; Rats ; Rats, Sprague-Dawley ; rho-Associated Kinases ; metabolism

This study was to report the effect of Tangshen Formula on phospholipids metabolism in diabetic nephropathy patients. A normal phase-HPLC-TOF/MS method was used in this study for the determination of seven species of phospholipids in human plasma. Then, the concentration changes of potential phospholipids biomarkers were discussed in diabetic nephropathy phase III and phase IV patients among different groups, including before and 3, 6 months after administration of Tangshen Formula. Significant increases of PE750, PI885, PC792, PC826, PC830, PC854 and PC802 levels were observed 6 months after administration of Tangshen Formula and conventional western medicine, as well as a decrease of LPC540 level, when compared with those before medication. Concentrations of all the potential phospholipids biomarkers showed a tendency towards normal levels; however, both the improvement degree and onset time of these compounds were not same. Additionally, Tangshen Formula treatment based on conventional western medicine treatment was more efficient in adjusting the levels of these compounds when compared with western medicine treatment alone, especially for the phase IV patients. These results indicated that Tangshen Formula was capable in regulating and improving phospholipids metabolism in diabetic nephropathy patients, which may be related with the direct or indirect inhibition of protein kinase C pathway and the corresponding reduction of phospholipase A2 activity. Therefore, Tangshen Formula may be used as an effective drug for diabetic nephropathy therapy, at least as an adjunctive therapeutic drug.
Diabetic Nephropathies ; blood ; metabolism ; Double-Blind Method ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Glycerophospholipids ; blood ; Humans ; Lysophosphatidylcholines ; blood ; Phospholipases A2 ; metabolism ; Phospholipids ; blood ; classification ; Plants, Medicinal ; chemistry ; Protein Kinase C ; metabolism ; Signal Transduction ; Sphingomyelins ; blood

In order to study the effect of and mechanism of lysophosphatidylcholine (LysoPC) on proliferation of the calf thoracic aorta smooth muscle cells (ASMCs), the ASMCs were used to observe the effects of LysoPC-induced endothelial cell conditioned medium on the DNA content and proliferating cell nuclear antigen (PCNA) expression in the calf thoracic ASMCs by flow cytometry and Western Blot technique. It was found that LysoPC-induced endothelial cell conditioned medium could significantly promote PCNA expression of the calf ASMCs, induce the converting of ASMCs from G0/G1 phase to S phase of DNA synthesis, and increase the tyrosine phosphorylation protein expression. Tyrosine protein kinase inhibitor (TPKi) RG50864 could obviously inhibit proliferation of LysoPC-induced ASMCs in a dose-dependence manner. The results indicated that the effect of LysoPC promoting the proliferation of ASMCs is partly evoked by endothelial cell derived growth factors such as PDGF and so on.
Animals ; Aorta ; cytology ; Cattle ; Cell Division ; drug effects ; Cells, Cultured ; Culture Media, Conditioned ; Lysophosphatidylcholines ; pharmacology ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Platelet-Derived Growth Factor ; metabolism ; Proliferating Cell Nuclear Antigen ; metabolism