OBJECTIVETo provide more detailed information on the roles of lipid peroxidation in the pathogenesis of chronic pancreatic injuries in a pre-clinical rat model.

METHODSTotally 72 rats were divided into 6 groups (12 in each group) Rats in 5 experimental groups (n = 12) were fed with a high-fat diet (1% cholesterol, 10% lard, 0.3% sodium tauroglycocholate, 87.3% standard rodent chow as the control group) for 2, 4, 6, 10 and 16 weeks, respectively. Morphological studies in the pancreas tissue samples from rats were investigated by using various histological methods. Pancreatic stellate cells (PSCs) were identified by immunohistochemical staining for Desmin and α-smooth muscle actin (α-SMA). The expression of the lipid peroxidation was detected by immunostaining for 4-hydroxy-2-nonenal (4-HNE) and thromboxane A2 receptor (TxA2r). The co-localization of α-SMA and 4-HNE or α-SMA and TxA2r in PSCs was also analyzed in this study.

RESULTSPancreatic cells with positive staining for Desmin and α-SMA in HFD rats were distributed in a more extensive way when compared to that in the control group. The levels of pancreatic 4-HNE and TxA2r were increased in rats from HFD groups significantly. The co-localization of 4-HNE and TxA2r were also found within activated PSCs in both of groups.

CONCLUSIONThe results showed that a chronic HFD feeding may increase the lipid peroxidation process and collagen synthesis through a critical signaling pathway of activated PSCs following pancreatic injuries in rats.

Actins ; metabolism ; Aldehydes ; metabolism ; Animals ; Collagen ; biosynthesis ; Desmin ; metabolism ; Diet, High-Fat ; adverse effects ; Disease Models, Animal ; Lipid Peroxidation ; Male ; Oxidative Stress ; Pancreas ; metabolism ; pathology ; Pancreatic Diseases ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Receptors, Thromboxane A2, Prostaglandin H2 ; metabolism

Anti-Inflammatory Agents, Non-Steroidal ; adverse effects ; pharmacology ; Cardiovascular Diseases ; chemically induced ; Celecoxib ; Cyclooxygenase 1 ; metabolism ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase 2 Inhibitors ; adverse effects ; pharmacology ; Epoprostenol ; biosynthesis ; Humans ; Lactones ; adverse effects ; pharmacology ; Pyrazoles ; adverse effects ; pharmacology ; Sulfonamides ; adverse effects ; pharmacology ; Sulfones ; adverse effects ; pharmacology ; Thromboxane A2 ; metabolism

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

The present study was designed to target fish for potential bioactive components contained in a Huang Lian Jie Du decoction (HLJDD) and identify the underlying mechanisms of action for the treatment of sepsis at the molecular level. he bioactive components database of HLJDD was constructed and the sepsis-associated targets were comprehensively investigated. The 3D structures of the PAFR and TXA2R proteins were established using the homology modelling (HM) method, and the molecular effects for sepsis treatment were analysed by comparing the bioactive components database and the sepsis targets using computational biology methods. The results of the screening were validated with biological testing against the human oral epidermal carcinoma cell line KB in vitro. We found that multiple bioactive compounds contained in the HLJDD interacted with multiple targets. We also predicted the promising compound leads for sepsis treatment, and the first 28 compounds were characterized. Several compounds, such as berberine, berberrubine and epiberberine, dose-dependently inhibited PGE2 production in human KB cells, and the effects were similar in the presence or absence of TPA. This study demonstrates a novel approach to identifying natural chemical compounds as new leads for the treatment of sepsis.
Anti-Inflammatory Agents, Non-Steroidal ; pharmacokinetics ; Berberine ; analogs & derivatives ; pharmacokinetics ; Dinoprostone ; biosynthesis ; Drugs, Chinese Herbal ; chemistry ; pharmacokinetics ; Humans ; KB Cells ; Platelet Membrane Glycoproteins ; drug effects ; Protein Transport ; Receptors, G-Protein-Coupled ; drug effects ; Receptors, Thromboxane A2, Prostaglandin H2 ; drug effects ; Sepsis ; drug therapy ; metabolism ; Tetradecanoylphorbol Acetate ; pharmacokinetics