OBJECTIVETo explore the role of phospholipase C-gamma1 (PLC-gamma1) signaling pathway in H(2)O(2)-induced apoptosis of PC12 cells.

METHODSPC12 cells were exposed to 50 micromol/L H(2)O(2) after pretreatment with 10 micromol/L U73122, a specific PLC-gamma1 inhibitor. Hoechst/PI double staining was performed to observe the morphological changes of the cells under light microscope. MTT assay was used to evaluate the cell viability, and the percentage of apoptotic cells was analyzed by flow cytometry. DNA fragmentation assay was carried out to characterize the cell apoptosis.

RESULTSAfter inhibition of the PLC-gamma1 signaling pathway with 10 micromol/L U73122, PC12 cells showed obvious apoptotic morphology, the viable cells decreased significantly, and the percentage of apoptotic cells rose to 35.7%. PC12 cells treated with U73122 presented with a distinct DNA ladder on electrophoresis resulting from DNA cleavage in the apoptotic cells.

CONCLUSIONPLC-gamma1 signaling pathway plays an important protective role in H(2)O(2)-induced PC12 cell apoptosis.

Animals ; Apoptosis ; drug effects ; Estrenes ; pharmacology ; Hydrogen Peroxide ; pharmacology ; PC12 Cells ; Phospholipase C gamma ; antagonists & inhibitors ; metabolism ; Pyrrolidinones ; pharmacology ; Rats ; Signal Transduction

Resveratrol (RESV) is a polyphenolic compound existed in native plants such as grape, fleeceflower root, and peanut, etc. The aim of this study was to investigate the effects in vitro of RESV on adenosine diphosphate (ADP)-induced platelet aggregation, platelet membrane-bound fibrinogen (PFig) its mechanism of action. The effects of RESV and phospholipase Cbeta inhibitor (U73122) on ADP-induced healthy human volunteers platelet aggregation, PFig, and the expression of phospho-phospholipase Cbeta3 (P-PLCbeta3) and total-phospholipase Cbeta3 (T-PLCbeta3) were studied with platelet aggregometer, flow cytometry and Western blotting, respectively. Compared with control group, RESV at 25, 50 and 100 micromol x L(-1) inhibited ADP-induced platelet aggregation and PFig in a dose dependent manner, and RESV at 25 micromol x L(-1) obviously reduced expression of P-PLCbeta3 and ratio of P-PLCbeta3 to T-PLCbeta3 in platelet of healthy human volunteers. Furthermore, RESV and U73122 had additive effect in inhibiting platelet aggregation and PFig. All these suggested that RESV inhibited platelet aggregation and PFig induced by ADP partly through decreasing the activity of PLCbeta of platelets, and that RESV had definite effect of antiplatelet and might be developed as a novel antithrombotic agent.
Adenosine Diphosphate ; pharmacology ; Blood Platelets ; metabolism ; Dose-Response Relationship, Drug ; Drug Synergism ; Estrenes ; pharmacology ; Fibrinogen ; metabolism ; Humans ; Phospholipase C beta ; metabolism ; Platelet Aggregation ; drug effects ; Platelet Aggregation Inhibitors ; pharmacology ; Pyrrolidinones ; pharmacology ; Stilbenes ; pharmacology

Binding Sites ; Cysteine Endopeptidases ; metabolism ; Humans ; Isoxazoles ; chemistry ; pharmacology ; Protease Inhibitors ; chemistry ; metabolism ; pharmacology ; Protein Structure, Tertiary ; Pyrrolidinones ; chemistry ; pharmacology ; Rhinovirus ; drug effects ; SARS Virus ; drug effects ; enzymology ; Severe Acute Respiratory Syndrome ; virology ; Viral Proteins ; antagonists & inhibitors ; metabolism

Animals ; Dementia, Vascular ; drug therapy ; physiopathology ; Hippocampus ; metabolism ; physiopathology ; Learning ; drug effects ; Male ; Memory ; drug effects ; Nootropic Agents ; pharmacology ; therapeutic use ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Pyrrolidinones ; pharmacology ; therapeutic use ; Rats ; Rats, Sprague-Dawley

Our recent studies have shown that co-activation of Gq and Gi proteins by 5-hydroxytryptamine (5-HT) and adrenaline show synergism in human platelet aggregation. This study was conducted to examine the mechanism(s) of synergistic interaction of 5-HT and platelet activating factor (PAF) in human platelets. We show that PAF, but not 5-HT, increased platelet aggregation in a concentration-dependent manner. However, low concentrations of 5-HT (2 microM) potentiated platelet aggregation induced by subthreshold concentration of PAF (40 nM) indicating a synergistic interaction between the two agonists and this synergism was blocked by receptor antagonists to either 5-HT or PAF. 5-HT also potentiated the effect of PAF on thromboxane A2 (TXA2) formation and phosphorylation of extracellularly regulated mitogen-activated protein kinases (ERK1/2). The synergism of 5-HT and PAF in platelet aggregation was inhibited by calcium (Ca2+) channel blockers, verapamil and diltiazem, phospholipase C (PLC) inhibitor, U73122, cyclooxygenase (COX) inhibitor, indomethacin, and MEK inhibitor, PD98059. These data suggest that synergistic effect of 5-HT and PAF on human platelet aggregation involves activation of PLC/Ca2+, COX and MAP kinase pathways.
Diltiazem/pharmacology ; Dose-Response Relationship, Drug ; Drug Synergism ; Estrenes/pharmacology ; Flavones/pharmacology ; Human ; In Vitro ; Indomethacin/pharmacology ; Kinetics ; Mitogen-Activated Protein Kinases/metabolism ; Phosphorylation/drug effects ; Platelet Activating Factor/*pharmacology ; Platelet Activation/drug effects ; Platelet Aggregation/*drug effects/physiology ; Pyrrolidinones/pharmacology ; Serotonin/*pharmacology ; Thromboxane A2/biosynthesis ; Verapamil/pharmacology

Our recent studies have shown that co-activation of Gq and Gi proteins by 5-hydroxytryptamine (5-HT) and adrenaline show synergism in human platelet aggregation. This study was conducted to examine the mechanism(s) of synergistic interaction of 5-HT and platelet activating factor (PAF) in human platelets. We show that PAF, but not 5-HT, increased platelet aggregation in a concentration-dependent manner. However, low concentrations of 5-HT (2 microM) potentiated platelet aggregation induced by subthreshold concentration of PAF (40 nM) indicating a synergistic interaction between the two agonists and this synergism was blocked by receptor antagonists to either 5-HT or PAF. 5-HT also potentiated the effect of PAF on thromboxane A2 (TXA2) formation and phosphorylation of extracellularly regulated mitogen-activated protein kinases (ERK1/2). The synergism of 5-HT and PAF in platelet aggregation was inhibited by calcium (Ca2+) channel blockers, verapamil and diltiazem, phospholipase C (PLC) inhibitor, U73122, cyclooxygenase (COX) inhibitor, indomethacin, and MEK inhibitor, PD98059. These data suggest that synergistic effect of 5-HT and PAF on human platelet aggregation involves activation of PLC/Ca2+, COX and MAP kinase pathways.
Diltiazem/pharmacology ; Dose-Response Relationship, Drug ; Drug Synergism ; Estrenes/pharmacology ; Flavones/pharmacology ; Human ; In Vitro ; Indomethacin/pharmacology ; Kinetics ; Mitogen-Activated Protein Kinases/metabolism ; Phosphorylation/drug effects ; Platelet Activating Factor/*pharmacology ; Platelet Activation/drug effects ; Platelet Aggregation/*drug effects/physiology ; Pyrrolidinones/pharmacology ; Serotonin/*pharmacology ; Thromboxane A2/biosynthesis ; Verapamil/pharmacology

No abstract available.
Animal ; Biological Transport/physiology ; Biological Transport/drug effects ; Cholera/metabolism ; Diglycerides/pharmacology ; Epithelial Cells*/virology ; Epithelial Cells*/microbiology ; Epithelial Cells*/metabolism ; Escherichia coli ; Escherichia coli Infections/metabolism ; Estrenes/pharmacology ; In Vitro ; Indoles/pharmacology ; Influenza/metabolism ; Intestinal Mucosa/cytology ; Maleimides/pharmacology ; Mice ; Phosphodiesterase Inhibitors/pharmacology ; Pyrrolidinones/pharmacology ; Respiratory Mucosa/cytology ; Sodium Channels/metabolism* ; Staurosporine/pharmacology ; Vibrio cholerae

Monocyte chemoattractant protein-1 (MCP1) plays a key role in monocyte/macrophage infiltration to the sub-endothelial space of the blood vessel wall, which is a critical initial step in atherosclerosis. In this study, we examined the intracellular signaling pathway of IL-1beta-induced MCP1 expression using various chemical inhibitors. The pretreatment of a phosphatidylcholine (PC)-specific PLC (PC-PLC) inhibitor (D609), PKC inhibitors, or an NF-kappaB inhibitor completely suppressed the IL-1beta-induced MCP1 expression through blocking NF-kappaB translocation to the nucleus. Pretreatment with inhibitors of tyrosine kinase or PLD partially suppressed MCP1 expression and failed to block nuclear NF-kappaB translocation. These results suggest that IL-1beta induces MCP1 expression through activation of NF-kappaB via the PC-PLC/PKC signaling pathway.
Active Transport, Cell Nucleus/drug effects ; Aorta/pathology ; Atherosclerosis/immunology/metabolism ; Bridged Compounds/pharmacology ; Cell Nucleus/*metabolism ; Cells, Cultured ; Chemokine CCL2/*biosynthesis ; Estrenes/pharmacology ; Genistein/pharmacology ; Humans ; Interleukin-1beta/metabolism ; Myocytes, Smooth Muscle/drug effects/immunology/*metabolism/pathology ; NF-kappa B/*metabolism ; Phospholipases/antagonists & inhibitors ; Protein-Tyrosine Kinases/antagonists & inhibitors ; Pyrrolidinones/pharmacology ; Recombinant Proteins/metabolism ; Signal Transduction/*drug effects ; Thiones/pharmacology

OBJECTIVEObserve the effects of Goutengsan on SOD, MAO-B, GSH-PX, NO, LDH, index of brain, rate of death and so on in rats to study therapeutic effects and mechanism of Goutengsan on Alzheimer dementia (AD) model.

METHODOne hundred and twenty rats were randomly divided into 6 groups, 3 experimental groups of which were daily administrated with Goutengsan extract whereas the model and control groups were given NS (0.01 mL x g(-1)). Aniracetam at 0.1 g x kg(-1) served as a positive control. At the 5th day after administration, all groups except the control were administrated (ip) with AlCl3 (100 mg x kg(-1) ) for successive 50 days at 1 day interval. After administration, the death rate, body weight, training scores, brain index, MAO-B, SOD, GSH-Px in brain and NO, LDH in serum were determined.

RESULTThe brain index, SOD, GSH-Px activities as well as NO content of drug-treated groups were strikingly higher that of model group, and had not obvious difference from that of normal group except content of LDH was higher.

CONCLUSIONGoutengsan could increase the brain index, cut down the rate of death, stable increase of body weight, promote the endogenous antioxidant activity, enhance the clearance of lipid peroxide and other metabolic waste, inhibit the MAO-B activity, reduced the leakage of LDH and maintain the content of NO at a normal level. Therefore Goutengsan could protect cells, delay senile, improve symptoms of AD.

Aluminum Compounds ; pharmacology ; Alzheimer Disease ; chemically induced ; drug therapy ; metabolism ; Animals ; Body Weight ; drug effects ; Brain ; drug effects ; metabolism ; Chlorides ; pharmacology ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Female ; Glutathione Peroxidase ; metabolism ; Lipid Peroxidation ; drug effects ; Male ; Malondialdehyde ; metabolism ; Memory ; drug effects ; Nitric Oxide ; metabolism ; Oxidative Stress ; drug effects ; Pyrrolidinones ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism

OBJECTIVETo explore the role of phospholipase C-gamma1 (PLC-gamma1) in tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis of human glioma SWO cells.

METHODSThe PLC-gamma1 pathway was blocked by U73122 in SWO cells, and the inhibitory effect of TNF-alpha on SWO glioma cell proliferation with or without U73122 treatment was investigated by MTT assay. The cell apoptosis induced by TNF-alpha along or in combination with U73122 was detected by flow cytometry with PI staining. The expression of caspase-3 and Bcl-2 was detected by Western blotting.

RESULTS AND CONCLUSIONU73122 can sensitize SWO glioma cells to TNF-alpha-induced apoptosis. Blocking the PLC-gamma1 pathway may not induce apoptosis of SWO glioma cells, but can sensitize SWO glioma cells to small-dose TNF-alpha-induced apoptosis, the mechanism of which may involve down-regulation of bcl-2.

Apoptosis ; drug effects ; Blotting, Western ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Down-Regulation ; drug effects ; Estrenes ; pharmacology ; Flow Cytometry ; Glioma ; enzymology ; pathology ; Humans ; Phosphodiesterase Inhibitors ; pharmacology ; Phospholipase C gamma ; antagonists & inhibitors ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Pyrrolidinones ; pharmacology ; Signal Transduction ; drug effects ; Tumor Necrosis Factor-alpha ; pharmacology