Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and foun...Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.展开更多
AIM: To evaluate the changes in hepatic platelet activating factor (PAF) and its receptors and their effect on portal pressure of cirrhotic rats induced by CCh. METHODS: A model of liver cirrhosis was replicated i...AIM: To evaluate the changes in hepatic platelet activating factor (PAF) and its receptors and their effect on portal pressure of cirrhotic rats induced by CCh. METHODS: A model of liver cirrhosis was replicated in rats by intra-peritoneal injection of CCh for 8 wk. We determined the effect of hepatic PAF and its receptor level on portal and arterial pressure by EIA, saturation binding and RT-PCR technique. RESULTS: Compared to control rats, cirrhotic rats had higher hepatic PAF levels and output as well as higher plasma PAF levels (P〈0.01, P〈0.01, P〈0.05, respectively). Both hepatic PAF receptor mRNA levels and PAF binding were nearly 3-fold greater in cirrhotic rats (P〈0.01). Portal injection of PAF (1 g/kg WT) increased the portal pressure by 22% and 33% in control and cirrhotic rats, respectively. In contrast, the arterial pressure was decreased in the both groups (54% in control rats and 42% in cirrhotic rats). Injection of the PAF antagonist BN52021 (5 mg/kg WT) decreased the portal pressure by 16% in cirrhotic rats but had no effect in the control rats. CONCLUSION: The upregulation of the PAF system contributes to hepatic hemodynamic and metabolic abnormalities in drrhosis, and the increased release of PAF into the circulation has impacts on the systemic hemodynamics.展开更多
Arsenic in drinking water is a worldwide health problem that is associated with cardiovascular disease, but the cause is currently unknown. In order to examine whether arsenic affects vasomotor tone in blood vessels, ...Arsenic in drinking water is a worldwide health problem that is associated with cardiovascular disease, but the cause is currently unknown. In order to examine whether arsenic affects vasomotor tone in blood vessels, we investigated the effect of arsenic on agonist-induced vasorelaxation and vasoconstriction using the isolated rat aortic rings in in vitro organ bath system. Treatment with inorganic arsenite (AsⅢ) inhibited acetylcholine-induced relaxation of aortic rings by inhibiting production of nitric oxide in endothelium.展开更多
Objective: To investigate the effects of atorvastatin combined with clopidogrel on inflammatory factors, coagulation and platelet activation in patients with acute cerebral infarction. Methods: A total of 140 cases pa...Objective: To investigate the effects of atorvastatin combined with clopidogrel on inflammatory factors, coagulation and platelet activation in patients with acute cerebral infarction. Methods: A total of 140 cases patients with acute cerebral infarction who were confirmed by clinical and imaging diagnoses were randomly divided into treatment group (70 cases) and control group (70 cases). Both groups were treated routinely before treatment. The observation group was treated with clopidogrel and atorvastatin, while the control group was treated with aspirin and atorvastatin. The changes of inflammatory factors, coagulation function and platelet activation index before and after treatment were compared between the two groups. Result: Before treatment, the levels of serum soluble intercellular adhesion molecule-1 (sICAM-1), transforming growth factor-β (TGF-β), coagulation parameters prothrombin time(PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), coagulation index of platelets platelet -membrane glycoprotein (CD62p), lysosomal granular membrane glycoprotein (CD63), platelet-monocyte aggregates (PMA), coagulation parameters were not statistically significant. After treatment, the levels of sICAM-1, CD62p, CD63, PMA and FIB in both groups decreased and the levels of TGF-β, PT and APTT increased. The levels of sICAM-1, FIB, CD62p, CD63 and PMA in the observation group were (370.32±37.13) ng/mL, (1.97±0.21) g/L, (1.38±0.14)%, (0.22±0.02)%, and (18.47+1.85)% respectively, which were lower than those in the control group ((410.47±42.32) ng/mL, (2.58±0.26) s, (2.67±0.27)%, (0.35±0.03)% and (22.87±2.91)%)While the levels of TGF-β, PT and APPT were (231.53±23.52) ng/mL, (15.42±1.53) s, (37.31±3.54) s were higher than the control group ((218.56±22.17) ng/mL, (12.32±1.27) s and (29.89±3.01)s)And the differences were significant. Conclusion: Atorvastatin combined with clopidogrel treatment can effectively relieve the inflammatory response, reduce the release of inflammatory cytokines, improve blood coagulation and inhibit platelet aggregation in patients with acute cerebral infarction. So it deserves further clinical promotion.展开更多
The effects of isoproterenol (IPN) on histamine and platelet-activating factor (PAF)-induced vascular permeability increment in rat skin and in cultured confluent endothelial cell monolayer were investigated. The resu...The effects of isoproterenol (IPN) on histamine and platelet-activating factor (PAF)-induced vascular permeability increment in rat skin and in cultured confluent endothelial cell monolayer were investigated. The results showed that after intravenous administration of 20 mg/kg Evans blue (EB) dye, the intradermal injection of 0. 2 ml PAF(10-7mol/L) or histamine (0. 5 mmol/L) could induce the exudation of 16. 82+2. 05 μg/g tissue and 21. 86+2. 86μg/g tissue of EB respectively into the injected skin. Pretreatment of the rats with intravenous IPN (10 μg/kg) decreased the EB exudation by 56. 2% and 43. 6% respectively. Propranolol (PPN), a β-adrenoceptor blocker, reversed the inhibitory effects of IPN. In rats treated with PPN alone, intradermal injection of PAF and histamine induced significant increase of skin EB exudation in comparison with the control, indicating that catecholamines at physiologic concentration in vivo may have inhibitory effects on vascular permeability. When cultured endothelial cell monolayers were perfused with 1% albumin in Hanks' balanced salt solution the increased fluid flux and protein clearance caused by PAF were significantly decreased by IPN pretreatment. The results confirmed the inhibitory effects of IPN on vascular permeability increment induced by PAF at the cellular level.展开更多
Objective To investigate lipopolysaccharide (LPS) induced acute cerebral inflammatory damage and the therapeutic effect of ginkgolide B (BN52021). Methods Thirty Sprague-Dawley rats were randomly divided into 3 gr...Objective To investigate lipopolysaccharide (LPS) induced acute cerebral inflammatory damage and the therapeutic effect of ginkgolide B (BN52021). Methods Thirty Sprague-Dawley rats were randomly divided into 3 groups (n = 10 for each group): Control group, Model group and Treatment group (treated with BN52021). LPS were injected into the fourth ventricle of rat to make a neuroinflammatory murine model. Morris water maze was used to detect the learning and memory ability of rats; changes of synapse number and subcellular ultrastructures were observed under a transmission electron microscope; OX-42 positive microglia in the brain was detected by immunohistochemical method. Results The average escape latency in the Treatment group were significantly shortened than that in the Model group; and the percentage of swimming distance traveled in platform quadrant accounting for total distance increased markedly. The rough endoplasmic reticulum and polyribosomes in the Treatment group were more than that in the Model group, but the number of synapses seemed to have no obvious change. The number of OX-42 positive microglia in the Treatment group decreased markedly than that in the Model group, and the grey density of OX-42-positive cells increased significantly. Conclusion LPS can induce inflammatory damages to the brain, but the damage could be antagonized by BN52021. Platelet activating factor receptor antagonist may offer an effective therapy for neurodegeneration diseases.展开更多
AIM:To investigate the dynamic changes and significance of platelet activating factor receptor (PAF-R) mRNA and protein in pancreatic tissues of rats with severe acute pancreatitis (SAP) and effects of BN52021 (Ginkgo...AIM:To investigate the dynamic changes and significance of platelet activating factor receptor (PAF-R) mRNA and protein in pancreatic tissues of rats with severe acute pancreatitis (SAP) and effects of BN52021 (Ginkgolide B). METHODS:Wistar male rats were randomly assigned to the negative control group (NC group),SAP model group (SAP group),and BN52051-remedy group (BN group),and each of the groups was divided into 6 subgroups at different time points after operation (1 h,2 h,3 h,6 h,12 h,and 24 h) (n=10 in each). PT-PCR and Western blot methods were used to detect PAF-RmRNA and protein expression in pancreatic tissues of rats respectively. Pathological examination of pancreatic tissues was performed and the serum amylase change was detected. RESULTS:Serum amylase and pathological results showed the that SAP model was successfully prepared,BN52021 was able to decrease serum amylase,and the pathological ratings in BN group at 3 h,6 h,and 12 h significantly decreased compared with those in the SAP group (8.85 ± 0.39 vs 5.95 ± 0.19,9.15 ± 0.55 vs 5.55 ± 0.36,10.10 ± 0.65 vs 6.72 ± 0.30,P < 0.05). The result of PAF-mRNA showed dynamic changes in SAP and BN groups,which increased gradually in early stage,reached a peak at 3 h (0.71 ± 0.14 vs 0.54 ± 0.14,0.69 ± 0.13 vs 0.59 ± 0.04,P < 0.05),and decreased gradually later. There were significant differences at each time point except 1 h and 2 h,when compared with those in the NC group (0.71 ± 0.14 or 0.69 ± 0.13 vs 0.47 ± 0.10,0.38 ± 0.08 or 0.59 ± 0.04 vs 0.47 ± 0.09,0.25 ± 0.07 or 0.29 ± 0.05 vs 0.46 ± 0.10,0.20 ± 0.06 or 0.20± 0.04 vs 0.43 ± 0.09,P < 0.05),whereas there was no significant difference between BN and SAP groups at each time point. The result of PAF-R protein showed that the change of PAF-R protein in the SAP group and the BN group was consistent with that of PAF-R mRNA. There were significant differences at each time point except 1 h,when compared with those in the NC group (0.90 ± 0.02 or 0.80 ± 0.05 vs 0.48 ± 0.02,1.69 ± 0.06 or 1.58 ± 0.02 vs 0.48 ± 0.03,1.12 ± 0.10 or 0.98 ± 0.03 vs 0.49 ± 0.09,1.04 ± 0.14 or 0.87 ± 0.02 vs 0.52 ± 0.08,0.97 ± 0.16 or 0.90 ± 0.05 vs 0.49 ± 0.10,P < 0.05),whereas there was no significant difference between the BN group and the SAP group. CONCLUSION:PAF-R plays an important role in occurrence and development of SAP. BN52021 exerts biological effects through competitively inhibiting the binding of increased both PAF and PAF-R expression rather than through decreasing PAF-R expression in pancreatic tissues.展开更多
Objective The mechanism through which platelet activating factor (PAF) induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion cha...Objective The mechanism through which platelet activating factor (PAF) induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion channels in its action. The present study was aimed to clarify the role of PAF in fatal arrhythmias following acute myocardia infarction (AMI) and the underlying mechanism. Methods (1) Blood PAF levels were measured among 72 AMI patients at the time of diagnosis with AMI and 48 h later, and their electrocardiogram (ECG) was recorded continuously. (2) Ischemia simulation and surface electrocardiogram were conducted in 20 pigs and their PAF levels were measured. (3) PAF perfusion and standard microelectrode recording were performed on guinea pig papillarymuscles. Results In both humans and pigs, elevated PAF levels were detected in AMI and simulated ischemia, respectively, and even higher PAF levels were found when fatal arrhythmias occurred. In guinea pig myocardium, PAF induced a shortening of action potential duration at 90% level of repolarization (APD 90 )under non-ischemic conditions and a more pronounced shortening under early simulated ischemic conditions. Conclusion AMI and ischemia are associated with increased PAF levels in humans and pigs, which are further raised when fatal arrhythmia follows. The effects of PAF on the myocardium may be mediated by multiple ion channels.展开更多
To explore the effect of Buyang Huanwu Decoction (BHD) on platelet activating factor (PAF) content in arterial blood pre- and post-arterial thrombosis in rats, male Wistar rats were randomly divided into 3 groups, the...To explore the effect of Buyang Huanwu Decoction (BHD) on platelet activating factor (PAF) content in arterial blood pre- and post-arterial thrombosis in rats, male Wistar rats were randomly divided into 3 groups, the medicine group treated with BHD, the control group with dexamethasone liquid, and the blank group with distilled water. Oral administration was given for 14 consecutive days, once daily. Model of arterial thrombosis was established in the animals 2 hours after final medication, the blood content of PAF, dry weight (DW) and occlusion time (OT) of thrombus, and dry weight of thrombus/body weight (TW/BW) ratio were observed. Results indicated that BHD could markedly lower the arterial blood content of PAF after thrombosis, increase the OT of thrombus, reduce the dry weight of thrombus and the TW/BW ratio (P展开更多
AIM:To determine the platelet-activating factor (PAF) synthesis and its receptor expression in Kupffer cells in rat carbon tetrachloride-induced cirrhosis. METHODS:Kupffer cells, isolated from the livers of control an...AIM:To determine the platelet-activating factor (PAF) synthesis and its receptor expression in Kupffer cells in rat carbon tetrachloride-induced cirrhosis. METHODS:Kupffer cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were placed in serum-free medium overnight. PAF saturation binding, ET-1 saturation and competition binding were assayed. ET-1 induced PAF synthesis, mRNA expression of PAF, preproendothelin-1, endothelin A (ETA) and endothelin B (ETB) receptors were also determined. RESULTS:A two-fold increase of PAF synthesis (1.42 ± 0.14 vs 0.66 ± 0.04 pg/μg DNA) and a 1.48-fold increase of membrane-bound PAF (1.02 ± 0.06 vs 0.69 ± 0.07 pg/μg DNA) were observed in activated Kupffer cells of cirrhotic rats. The application of ET-1 to Kupffer cells induced PAF synthesis in a concentration-dependent manner in both cirrhotic and normal rats via ETB receptor, but PAF synthesis in the activated Kupffer cells was more effective than that in the normal Kupffer cells. In activated Kupffer cells, PAF receptor expression and PAF binding capacity were markedly enhanced. Activated Kupffer cells raised the [125I]-ET-1 binding capacity, but changed neither the affinity of the receptors, nor the expression of ETA receptor. CONCLUSION:Kupffer cells in the course of CCl4-induced cirrhosis are the main source of increased PAF. ET-1 is involved endogenously in stimulating the PAF synthesis in activated Kupffer cells via ETB receptor by paracrine. ETA receptor did not appear in activated Kupffer cells, which may exacerbate the hepatic and extrahepatic complications of cirrhosis.展开更多
INTRODUCTION Previous clinical and experimental studies haveindicated that an early endotoxemia occurred after amajor burn.It is unlikely that burn wound sepsis isthe source of circulating endotoxin in less than 12hou...INTRODUCTION Previous clinical and experimental studies haveindicated that an early endotoxemia occurred after amajor burn.It is unlikely that burn wound sepsis isthe source of circulating endotoxin in less than 12hour after burn.Increasing evidence demonstratesthat the bacteria and endotoxin in thegastrointestinal tract can pass through the gutbarrier into blood circulation to form enterogenicendotoxemia following burn.However。展开更多
Since its discovery nearly thirty years ago, platelet-activating factor has emerged as one of the more important lipidmediators known. Platelet-activating factor (PAF; 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphorylcholi...Since its discovery nearly thirty years ago, platelet-activating factor has emerged as one of the more important lipidmediators known. Platelet-activating factor (PAF; 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphorylcholine) exists en-dogenously as a mixture of molecular species with structural variants of the alkyl moiety. PAF is a novel potent signal-ing phospholipid that has unique pleiotropic biological properties in addition to platelet activation. PAF also plays a sig-nificant role in reproduction. PAF content in squirrel monkey sperm is significantly higher during the breeding seasonthan the non-breeding season. PAF content in human sperm has a positive correlation with seminal parameters and preg-nancy outcomes. High-fertility boars have significantly more PAF in their sperm than low-fertility boars. The enzymes(lyso-PAF-acetyltransferase and PAF-acetylhydrolase) necessary for PAF activation and deactivation are present insperm. PAF-acetylhydrolase may act as a 'decapacitation factor'. Removal of this enzyme during capacitation maypromote PAF synthesis increasing motility and fertilization. PAF also plays a significant role in the fertilization process,enhancing the fertilization rates of oocytes. Enhanced embryo development has also been reported in oocytes fertilizedwith PAF-treated sperm. PAF antagonists inhibit sperm motility, acrosome reaction, and fertilization, thus suggestingthe presence of receptors for PAF. The PAF-receptor is present on sperm, with altered transcript levels and distributionpatterns on abnormal cells. Whereas the exact mechanism of PAF in sperm function and reproduction is uncertain, itsimportance in normal fertility is substantial. The reproductive significance of PAF activity in sperm and fertility plus therole of PAF in the establishment of pregnancy requires further study.展开更多
AIM: To determine platelet activating factor (PAF) receptor expression in cirrhotic hepatic stellate cells.METHODS: Hepatic stellate cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were pla...AIM: To determine platelet activating factor (PAF) receptor expression in cirrhotic hepatic stellate cells.METHODS: Hepatic stellate cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were placed in serum-free medium after overnight culture. We determined the PAF receptor in hepatic stellate cells by saturation binding technique and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and the effects of PAF and its antagonist BN52021 on prostaglandin E2 (PGE2) release by stellate cells.RESULTS: Scatchard analysis indicated the presence of PAF receptor with dissociation constant (Kd) of 4.66 nmol/L and maximum binding capacity (Bmax) of 24.65 fmol/μg in cirrhotic stellate cells. Compared with the control, the maximum PAF binding capacity increased significantly (Bmax: 24.65 ± 1.96 fmol/μg. DNA, R = 0.982 vs 5.74 ± 1.55 fmol/μg. DNA, R = 0.93; P < 0.01), whereas receptor affinity had no significant difference (Kd of 4.66 ± 0.33 nmol/L for the cirrhosis and 3.51 ± 0.26 nmol/L for the control; P > 0.05). Consistent with the receptor binding data, the mRNA expression of PAF receptor was increased significantly in cirrhotic stellate cells. PAF in a concentration-dependent manner induced PGE2 synthesis in cirrhotic hepatic stellate cells, but the effects were blocked significantly by BN52021.CONCLUSION: Cirrhosis sensitizes hepatic stellate cells to PAF by elevating its receptor level and hepatic stellate cells maybe potential effectors of PAF induced portal hypertension.展开更多
Traumatic brain injury causes gene expression changes in different brain regions. Occurrence and development of traumatic brain injury are closely related, involving expression of three factors, namely cyclooxygenase-...Traumatic brain injury causes gene expression changes in different brain regions. Occurrence and development of traumatic brain injury are closely related, involving expression of three factors, namely cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. However, little is known about the correlation of these three factors and brain neuronal injury. In this study, primary cultured rat hippocampal neurons were subjected to fluid percussion injury according to Scott’s method, with some modifications. RT-PCR and semi-quantitative immunocytochemical staining was used to measure the expression levels of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. Our results found that cyclooxygenase-2 expression were firstly increased post-injury, and then decreased. Both mRNA and protein expression levels reached peaks at 8 and 12 hours post-injury, respectively. Similar sequential changes in glutamate receptor 2 were observed, with highest levels mRNA and protein expression at 8 and 12 hours post-injury respectively. On the contrary, the expressions of platelet activating factor receptor were firstly decreased post-injury, and then increased. Both mRNA and protein expression levels reached the lowest levels at 8 and 12 hours post-injury, respectively. Totally, our findings suggest that these three factors are involved in occurrence and development of hippocampal neuronal injury.展开更多
Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart di...Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart disease. Methods: To measure PAF levels in 100 controls, 23 elderly patients with cerebral infarction and 65 cases with coronary heart disease by reversed phase high-performance liquid chromatographic technique (rHPLC). Results:rHPLC is more convenient, sensitive,specific, and less confusing, compared with bio-assay. The level of plasma PAF in patients with cerebral infarction was higher than that in the controls (P<0.01), and in patients with coronary heart disease. Conclusion: Detection of PAF with rHPLC is more reliable and more accurate. The new assay has important significance in PAF research.展开更多
AIM: To determine the effects of BN52021 on platelet-activating factor receptor (PAFR) signaling molecules under lipopolysaccharide (LPS)-induced inflammatory conditions in MS1 cells. METHODS: MS1 cells (a mouse pancr...AIM: To determine the effects of BN52021 on platelet-activating factor receptor (PAFR) signaling molecules under lipopolysaccharide (LPS)-induced inflammatory conditions in MS1 cells. METHODS: MS1 cells (a mouse pancreatic islet endothelial cell line) were grown in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum, 2 mmol/L glutamine and 100 μg/mL penicillin/streptomycin in 5% CO 2 at 37 ℃. After growth to confluency in media, the cells were processed for subsequent studies. The MS1 cells received 0, 0.1, 1 and 10 μg/mL LPS in this experiment. The viability/prolifera-tion of the cells induced by LPS was observed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. Apoptosis and necrosis of the cells under the inflammatory condition described previously were observed using Hoechst 33342-propidium iodide staining. Adenylate cyclase (AC), phospholipase A 2 (PLA 2 ), phospholipase Cβ (PLCβ), protein tyrosine kinase (PTK), G protein-coupled receptor kinases (GRK) and p38-mitogen-activated protein kinase (p38 MAPK) mRNA in the PAFR signaling pathway were measured by real-time polymerase chain reaction. The protein expression level of phosphorylated AC (p-AC), phosphorylated PLA 2 (p-PLA 2 ), phosphorylated PTK (p-PTK), phosphorylated p38 MAPK (p-p38 MAPK), PLCβ and GRK was measured using Western blotting analysis. RESULTS: The activity of MS1 cells incubated with dif- ferent concentrations of LPS for 6 h decreased significantly in the 1 μg/mL LPS group (0.49 ± 0.10 vs 0.67 ± 0.13, P < 0.05) and 10 μg/mL LPS group (0.44 ± 0.10 vs 0.67 ± 0.13, P < 0.001), but not in 0.1 μg/mL group. When the incubation time was extended to 12 h (0.33 ± 0.05, 0.32 ± 0.03 and 0.25 ± 0.03 vs 0.69 ± 0.01) and 24 h (0.31 ± 0.01, 0.29 ± 0.03 and 0.25 ± 0.01 vs 0.63 ± 0.01), MS1 cell activity decreased in all LPS concentration groups compared with the blank control (P < 0.001). BN52021 significantly improved the cell activity when its concentration reached 50 μmol/L compared with the group that received LPS treatment alone, which was consistent with the results obtained from fluorescence staining. The mRNAs levels of AC (4.02 ± 0.14 vs 1.00 ± 0.13), GRK (2.63 ± 0.03 vs 1.00 ± 0.12), p38 MAPK (3.87 ± 0.07 vs 1.00 ± 0.17), PLA 2 (3.31 ± 0.12 vs 1.00 ± 0.12), PLCβ (2.09 ± 0.08 vs 1.00 ± 0.06) and PTK (1.85 ± 0.07 vs 1.00 ± 0.11) were up-regulated after LPS stimulation as compared with the blank control (P < 0.05). The up- regulated mRNAs including AC (2.35 ± 0.13 vs 3.87 ± 0.08), GRK (1.17 ± 0.14 vs 2.65 ± 0.12), p38 MAPK (1.48 ± 0.18 vs 4.30 ± 0.07), PLCβ (1.69 ± 0.10 vs 2.41 ± 0.13) and PLA 2 (1.87 ± 0.11 vs 2.96 ± 0.08)were significantly suppressed by BN52021 except for that of PTK. The level of p-AC (1.11 ± 0.12 vs 0.65 ± 0.08), GRK (0.83 ± 0.07 vs 0.50 ± 0.03), PLCβ (0.83 ± 0.16 vs 0.50 ± 0.10) and p-p38 MAPK (0.74 ± 0.10 vs 0.38 ± 0.05) was up-regulated after LPS stimulation as compared with the blank control (P < 0.05). The up-regulated proteins, including p-AC (0.65 ± 0.15 vs 1.06 ± 0.14), GRK (0.47 ± 0.10 vs 0.80 ± 0.06), PLCβ (0.47 ± 0.04 vs 0.80 ± 0.19) and p-p38 MAPK (0.30 ± 0.10 vs 0.97 ± 0.05), was significantly suppressed by BN52021, but p-PLA 2 and p-PTK protein level were not suppressed. CONCLUSION: BN52021 could effectively inhibit LPS-induced inflammation by down-regulating the mRNA and protein levels of AC, GRK, p38 MAPK, PLA 2 and PLCβ in the PAFR signaling pathway.展开更多
Background:The effect of platelet factor 4(PF4)on bone marrow mesenchymal stem cells(BMMSCs)and osteoporosis is poorly understood.Therefore,this study aimed to evaluate the effects of PF4-triggered bone destruction in...Background:The effect of platelet factor 4(PF4)on bone marrow mesenchymal stem cells(BMMSCs)and osteoporosis is poorly understood.Therefore,this study aimed to evaluate the effects of PF4-triggered bone destruction in mice and determine the underlying mechanism.Methods:First,in vitro cell proliferation and cell cycle of BMMSCs were assessed using a CCK8 assay and flow cytometry,respectively.Osteogenic differentiation was confirmed using staining and quantification of alkaline phosphatase and Alizarin Red S.Next,an osteoporotic mouse model was established by performing bilateral ovariectomy(OVX).Furthermore,the PF4 concentrations were obtained using enzymelinked immunosorbent assay.The bone microarchitecture of the femur was evaluated using microCT and histological analyses.Finally,the key regulators of osteogenesis and pathways were investigated using quantitative real-time polymerase chain reaction and Western blotting.Results:Human PF4 widely and moderately decreased the cell proliferation and osteogenic differentiation ability of BMMSCs.Furthermore,the levels of PF4 in the serum and bone marrow were generally increased,whereas bone microarchitecture deteriorated due to OVX.Moreover,in vivo mouse PF4 supplementation triggered bone deterioration of the femur.In addition,several key regulators of osteogenesis were downregulated,and the integrinα5-focal adhesion kinase-extracellular signalregulated kinase(ITGA5-FAK-ERK)pathway was inhibited due to PF4 supplementation.Conclusions:PF4 may be attributed to OVX-i nduced bone loss triggered by the suppression of bone formation in vivo and alleviate BMMSC osteogenic differentiation by inhibiting the ITGA5-FAK-ERK pathway.展开更多
A simple and rapid method was established to study vascular permeability by in vitroperfused endothelial cell monolayers cultured on micropore filter membrane.It can be used todetermine filtration coefficient (K<s...A simple and rapid method was established to study vascular permeability by in vitroperfused endothelial cell monolayers cultured on micropore filter membrane.It can be used todetermine filtration coefficient (K<sub>f</sub>) to small molecules and osmotic reflection coefficient (σ) toproteins of the endothelial monolayer.Hanks’ balanced salt solution (HBSS) or 5g/L albuminin HBSS was used to perfuse the confluent endothelial monolayer at the hydrostatic pressure of2.45kPa (25cm H<sub>2</sub>O).Control K<sub>f</sub> values were 10.1±0.75 and 3.6±0.75μl·min<sup>-1</sup>·cm<sup>-2</sup>·kPa(-1)(±,n=3) respectively for the perfusion of HBSS and albumin HBSS,suggesting that al-bumin may decrease endothelial monolayer permeability to water and small molecules.After ex-posure of endothelial monolayer to 10<sup>-8</sup>mol/L platelet-activating factor (PAF) for 30min,K<sub>f</sub>values increased to 193.1% and 133.3% respectively.Protein clearance rate (μl.min<sup>-1</sup>·cm<sup>-2</sup>)and osmotic reflection coefficient of the control endothelial monolayer were 8.0±3.22 and 0.37±0.09 respectively and those of the PAF treated endothelial monolayer 12.2±2.95μl·min<sup>-1</sup>·cm<sup>-2</sup> and 0.18±0.06,revealing increased permeability to albumin.Computer-assisted imageprocessing demonstrated that PAF treatment decreased cell area while increased cell form factorand intercellular space,suggesting that endothelial cells retracted and rounded,which may bean important mechanism of PAF-induced increase of vascular permeability.展开更多
BACKGROUND: Pharmacologic action of traditional Chinese medicine compound is the comprehensive effect of various ingredients, and the interactions of various ingredients are closely correlated with the final effect. ...BACKGROUND: Pharmacologic action of traditional Chinese medicine compound is the comprehensive effect of various ingredients, and the interactions of various ingredients are closely correlated with the final effect. In order to reveal the compatibility mechanism of buyang huanwu decoction (BHD)'s prescription in treating and preventing ischemic cerebrovascular disease, we need to explore the effect and relation of ingredients in prescription except for considering the effect of each ingredient on the whole prescription. OBJECTIVE: To study the effect of BHD and its ingredients in the prescription on the specific binding of 3H-platelet activating factor (PAF) to its receptor (PAFR)in rabbits in vitro, and to analyze the action of each ingredient in the prescription. DESIGN: A decomposed recipe study based on orthogonal test. SETTING: Guangzhou University of Traditional Chinese Medicine. MATERIALS: Five healthy adult New Zealand rabbits of either gender were provided by the Experimental Animal Center of Guangzhou University of Traditional Chinese medicine. The prescription herbal pieces were purchased from Foshan Kangpu Pharmaceuticals Company and Jianmin Pharmaceuticals Company, and were appraised by Professor Yanchen Xu from College of Traditional Chinese Medicine, Guangzhou University of Traditional Chinese Medicine. 3H-PAF was supplied by Amersham Co,Ltd.(Specific activity: 6.475 TBq/mmol;batch number:200402); PAF standard by Biomol Co., Ltd.(batch number: P1318V). METHODS: This experiment was carried out in the Laboratory of Nuclear Medicine, Guangzhou University of Traditional Chinese Medicine between September and December 2004. ①The seven influencing factors were selected: such as Shenghuangqi , Dangguiwei, Chishao, Dilong, Taoren, Honghua, Chuanxiong. Each factor was divided into two levels, selected or not selected. The tests were arranged according to L8 (27) orthogonal test table. ②The specific binding of 3H-PAF to its receptors in rabbits was measured by radioligand binding assay. The inhibitory rate of the specific binding was used as an assessing index. The inhibitory action of and on 3H-PAF to PAFR binding was analyzed and compared in vitro. The inhibitory action of each ingredient in the prescription BHD on 3H-PAF to PAFR binding was investigated and compared in vitro by direct analysis and analysis of variance of orthogonal test. MAIN OUTCOME MEASURES: Effect of 8 prescriptions for L8 (27) orthogonal test table on the specific binding inhibition rate of 3H-PAF and PAFR. RESULTS: According to results of variance analysis of orthogonal test, the inhibitory action of each ingredient in the prescription BHD on 3H-PAF to PAFR binding from the highest to the lowest was in turn Honghua, ShenghuangqL Taoren, Dilong, DangguiweL Chuanxiong, Chishao. Honghua, Shenghuangqi, Taoren, Dilong, Danguiwei were major influence factors to 3H-PAF to PAFR in rabbits (F = 187.829,144.446,59.521,5.018,4.265, P 〈 0.05- 0.01), but Chuanxiong and Chishao had not obviously inhibitory effect. The specific binding inhibition rate of prescriptions (except Shenghuangqi ) was obviously higher than that of one of prescriptions (Shenghuangqi included). CONCLUSION: The results of orthogonal test show that Honghua, ShenghuangqL Taoren, Dilong, Dangguiwei are major influencing factors to inhibit binding of sH-PAF to PAFR in rabbits, among which, Honghua is the strongest in ingredients of prescription BHD. The results also reveal that Shenghuangqi is able to weaken the inhibitory effect and to prevent the strong inhibitory effect of blood-activating drugs in BHD.展开更多
Effect of platelet activating factor(PAF) on blood spinal cord barrier in cervical cord injury was investigated. Methods: Spinal cord injury at C6 segment was induced with Allen’s ’method in cats. PAF and PAF recept...Effect of platelet activating factor(PAF) on blood spinal cord barrier in cervical cord injury was investigated. Methods: Spinal cord injury at C6 segment was induced with Allen’s ’method in cats. PAF and PAF receptor antagonist BN52021 were administered by arachnoid space and intravenous injection respectively, and their effects on PAF levels, blood spinal cord barrier and cervical cord edema in the injuried zone and adjacent cervical cord tissue following cervical cord injury were investigated. Results: PAF levels, Evens content and water content in the injuried and adjacent cervical cord tissues significantly increased following trauma. PAF levels, Evens content and water content were evidently elevated with PAF by arachnoid space injection. PAF receptor antagonist BN52021 could inhibit the increase in PAF levels and reduce Evens and water content in the cervical cord tissue following trauma. Conclusion: PAF is an important contributing factor causing post-traumatic damage to the blood spinal cord barrier, while PAF receptor antagonist can effectively relieve post-traumatic damage to the blood spinal cord barrier.展开更多
基金supported by the National Natural Science Foundation of China,Nos.31730031,32130060the National Natural Science Foundation of China,No.31971276(to JH)+1 种基金the Natural Science Foundation of Jiangsu Province,No.BK20202013(to XG)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(Major Program),No.19KJA320005(to JH)。
文摘Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.
基金Supported by the Key Scientific and Technological Research Foundation of the National 863 Program,No.2003AA208106Medical Outstandard Foundation of Army,No.04J020
文摘AIM: To evaluate the changes in hepatic platelet activating factor (PAF) and its receptors and their effect on portal pressure of cirrhotic rats induced by CCh. METHODS: A model of liver cirrhosis was replicated in rats by intra-peritoneal injection of CCh for 8 wk. We determined the effect of hepatic PAF and its receptor level on portal and arterial pressure by EIA, saturation binding and RT-PCR technique. RESULTS: Compared to control rats, cirrhotic rats had higher hepatic PAF levels and output as well as higher plasma PAF levels (P〈0.01, P〈0.01, P〈0.05, respectively). Both hepatic PAF receptor mRNA levels and PAF binding were nearly 3-fold greater in cirrhotic rats (P〈0.01). Portal injection of PAF (1 g/kg WT) increased the portal pressure by 22% and 33% in control and cirrhotic rats, respectively. In contrast, the arterial pressure was decreased in the both groups (54% in control rats and 42% in cirrhotic rats). Injection of the PAF antagonist BN52021 (5 mg/kg WT) decreased the portal pressure by 16% in cirrhotic rats but had no effect in the control rats. CONCLUSION: The upregulation of the PAF system contributes to hepatic hemodynamic and metabolic abnormalities in drrhosis, and the increased release of PAF into the circulation has impacts on the systemic hemodynamics.
文摘Arsenic in drinking water is a worldwide health problem that is associated with cardiovascular disease, but the cause is currently unknown. In order to examine whether arsenic affects vasomotor tone in blood vessels, we investigated the effect of arsenic on agonist-induced vasorelaxation and vasoconstriction using the isolated rat aortic rings in in vitro organ bath system. Treatment with inorganic arsenite (AsⅢ) inhibited acetylcholine-induced relaxation of aortic rings by inhibiting production of nitric oxide in endothelium.
文摘Objective: To investigate the effects of atorvastatin combined with clopidogrel on inflammatory factors, coagulation and platelet activation in patients with acute cerebral infarction. Methods: A total of 140 cases patients with acute cerebral infarction who were confirmed by clinical and imaging diagnoses were randomly divided into treatment group (70 cases) and control group (70 cases). Both groups were treated routinely before treatment. The observation group was treated with clopidogrel and atorvastatin, while the control group was treated with aspirin and atorvastatin. The changes of inflammatory factors, coagulation function and platelet activation index before and after treatment were compared between the two groups. Result: Before treatment, the levels of serum soluble intercellular adhesion molecule-1 (sICAM-1), transforming growth factor-β (TGF-β), coagulation parameters prothrombin time(PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), coagulation index of platelets platelet -membrane glycoprotein (CD62p), lysosomal granular membrane glycoprotein (CD63), platelet-monocyte aggregates (PMA), coagulation parameters were not statistically significant. After treatment, the levels of sICAM-1, CD62p, CD63, PMA and FIB in both groups decreased and the levels of TGF-β, PT and APTT increased. The levels of sICAM-1, FIB, CD62p, CD63 and PMA in the observation group were (370.32±37.13) ng/mL, (1.97±0.21) g/L, (1.38±0.14)%, (0.22±0.02)%, and (18.47+1.85)% respectively, which were lower than those in the control group ((410.47±42.32) ng/mL, (2.58±0.26) s, (2.67±0.27)%, (0.35±0.03)% and (22.87±2.91)%)While the levels of TGF-β, PT and APPT were (231.53±23.52) ng/mL, (15.42±1.53) s, (37.31±3.54) s were higher than the control group ((218.56±22.17) ng/mL, (12.32±1.27) s and (29.89±3.01)s)And the differences were significant. Conclusion: Atorvastatin combined with clopidogrel treatment can effectively relieve the inflammatory response, reduce the release of inflammatory cytokines, improve blood coagulation and inhibit platelet aggregation in patients with acute cerebral infarction. So it deserves further clinical promotion.
文摘The effects of isoproterenol (IPN) on histamine and platelet-activating factor (PAF)-induced vascular permeability increment in rat skin and in cultured confluent endothelial cell monolayer were investigated. The results showed that after intravenous administration of 20 mg/kg Evans blue (EB) dye, the intradermal injection of 0. 2 ml PAF(10-7mol/L) or histamine (0. 5 mmol/L) could induce the exudation of 16. 82+2. 05 μg/g tissue and 21. 86+2. 86μg/g tissue of EB respectively into the injected skin. Pretreatment of the rats with intravenous IPN (10 μg/kg) decreased the EB exudation by 56. 2% and 43. 6% respectively. Propranolol (PPN), a β-adrenoceptor blocker, reversed the inhibitory effects of IPN. In rats treated with PPN alone, intradermal injection of PAF and histamine induced significant increase of skin EB exudation in comparison with the control, indicating that catecholamines at physiologic concentration in vivo may have inhibitory effects on vascular permeability. When cultured endothelial cell monolayers were perfused with 1% albumin in Hanks' balanced salt solution the increased fluid flux and protein clearance caused by PAF were significantly decreased by IPN pretreatment. The results confirmed the inhibitory effects of IPN on vascular permeability increment induced by PAF at the cellular level.
文摘Objective To investigate lipopolysaccharide (LPS) induced acute cerebral inflammatory damage and the therapeutic effect of ginkgolide B (BN52021). Methods Thirty Sprague-Dawley rats were randomly divided into 3 groups (n = 10 for each group): Control group, Model group and Treatment group (treated with BN52021). LPS were injected into the fourth ventricle of rat to make a neuroinflammatory murine model. Morris water maze was used to detect the learning and memory ability of rats; changes of synapse number and subcellular ultrastructures were observed under a transmission electron microscope; OX-42 positive microglia in the brain was detected by immunohistochemical method. Results The average escape latency in the Treatment group were significantly shortened than that in the Model group; and the percentage of swimming distance traveled in platform quadrant accounting for total distance increased markedly. The rough endoplasmic reticulum and polyribosomes in the Treatment group were more than that in the Model group, but the number of synapses seemed to have no obvious change. The number of OX-42 positive microglia in the Treatment group decreased markedly than that in the Model group, and the grey density of OX-42-positive cells increased significantly. Conclusion LPS can induce inflammatory damages to the brain, but the damage could be antagonized by BN52021. Platelet activating factor receptor antagonist may offer an effective therapy for neurodegeneration diseases.
基金the National Natural Science Foundation of China, No. 30300465
文摘AIM:To investigate the dynamic changes and significance of platelet activating factor receptor (PAF-R) mRNA and protein in pancreatic tissues of rats with severe acute pancreatitis (SAP) and effects of BN52021 (Ginkgolide B). METHODS:Wistar male rats were randomly assigned to the negative control group (NC group),SAP model group (SAP group),and BN52051-remedy group (BN group),and each of the groups was divided into 6 subgroups at different time points after operation (1 h,2 h,3 h,6 h,12 h,and 24 h) (n=10 in each). PT-PCR and Western blot methods were used to detect PAF-RmRNA and protein expression in pancreatic tissues of rats respectively. Pathological examination of pancreatic tissues was performed and the serum amylase change was detected. RESULTS:Serum amylase and pathological results showed the that SAP model was successfully prepared,BN52021 was able to decrease serum amylase,and the pathological ratings in BN group at 3 h,6 h,and 12 h significantly decreased compared with those in the SAP group (8.85 ± 0.39 vs 5.95 ± 0.19,9.15 ± 0.55 vs 5.55 ± 0.36,10.10 ± 0.65 vs 6.72 ± 0.30,P < 0.05). The result of PAF-mRNA showed dynamic changes in SAP and BN groups,which increased gradually in early stage,reached a peak at 3 h (0.71 ± 0.14 vs 0.54 ± 0.14,0.69 ± 0.13 vs 0.59 ± 0.04,P < 0.05),and decreased gradually later. There were significant differences at each time point except 1 h and 2 h,when compared with those in the NC group (0.71 ± 0.14 or 0.69 ± 0.13 vs 0.47 ± 0.10,0.38 ± 0.08 or 0.59 ± 0.04 vs 0.47 ± 0.09,0.25 ± 0.07 or 0.29 ± 0.05 vs 0.46 ± 0.10,0.20 ± 0.06 or 0.20± 0.04 vs 0.43 ± 0.09,P < 0.05),whereas there was no significant difference between BN and SAP groups at each time point. The result of PAF-R protein showed that the change of PAF-R protein in the SAP group and the BN group was consistent with that of PAF-R mRNA. There were significant differences at each time point except 1 h,when compared with those in the NC group (0.90 ± 0.02 or 0.80 ± 0.05 vs 0.48 ± 0.02,1.69 ± 0.06 or 1.58 ± 0.02 vs 0.48 ± 0.03,1.12 ± 0.10 or 0.98 ± 0.03 vs 0.49 ± 0.09,1.04 ± 0.14 or 0.87 ± 0.02 vs 0.52 ± 0.08,0.97 ± 0.16 or 0.90 ± 0.05 vs 0.49 ± 0.10,P < 0.05),whereas there was no significant difference between the BN group and the SAP group. CONCLUSION:PAF-R plays an important role in occurrence and development of SAP. BN52021 exerts biological effects through competitively inhibiting the binding of increased both PAF and PAF-R expression rather than through decreasing PAF-R expression in pancreatic tissues.
文摘Objective The mechanism through which platelet activating factor (PAF) induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion channels in its action. The present study was aimed to clarify the role of PAF in fatal arrhythmias following acute myocardia infarction (AMI) and the underlying mechanism. Methods (1) Blood PAF levels were measured among 72 AMI patients at the time of diagnosis with AMI and 48 h later, and their electrocardiogram (ECG) was recorded continuously. (2) Ischemia simulation and surface electrocardiogram were conducted in 20 pigs and their PAF levels were measured. (3) PAF perfusion and standard microelectrode recording were performed on guinea pig papillarymuscles. Results In both humans and pigs, elevated PAF levels were detected in AMI and simulated ischemia, respectively, and even higher PAF levels were found when fatal arrhythmias occurred. In guinea pig myocardium, PAF induced a shortening of action potential duration at 90% level of repolarization (APD 90 )under non-ischemic conditions and a more pronounced shortening under early simulated ischemic conditions. Conclusion AMI and ischemia are associated with increased PAF levels in humans and pigs, which are further raised when fatal arrhythmia follows. The effects of PAF on the myocardium may be mediated by multiple ion channels.
文摘To explore the effect of Buyang Huanwu Decoction (BHD) on platelet activating factor (PAF) content in arterial blood pre- and post-arterial thrombosis in rats, male Wistar rats were randomly divided into 3 groups, the medicine group treated with BHD, the control group with dexamethasone liquid, and the blank group with distilled water. Oral administration was given for 14 consecutive days, once daily. Model of arterial thrombosis was established in the animals 2 hours after final medication, the blood content of PAF, dry weight (DW) and occlusion time (OT) of thrombus, and dry weight of thrombus/body weight (TW/BW) ratio were observed. Results indicated that BHD could markedly lower the arterial blood content of PAF after thrombosis, increase the OT of thrombus, reduce the dry weight of thrombus and the TW/BW ratio (P
基金the Major Science and Technology Research Fund of the National 863 Program, No. 2003AA208106the Fund for Outstanding Medical Scientists of PLA, No. 04J020
文摘AIM:To determine the platelet-activating factor (PAF) synthesis and its receptor expression in Kupffer cells in rat carbon tetrachloride-induced cirrhosis. METHODS:Kupffer cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were placed in serum-free medium overnight. PAF saturation binding, ET-1 saturation and competition binding were assayed. ET-1 induced PAF synthesis, mRNA expression of PAF, preproendothelin-1, endothelin A (ETA) and endothelin B (ETB) receptors were also determined. RESULTS:A two-fold increase of PAF synthesis (1.42 ± 0.14 vs 0.66 ± 0.04 pg/μg DNA) and a 1.48-fold increase of membrane-bound PAF (1.02 ± 0.06 vs 0.69 ± 0.07 pg/μg DNA) were observed in activated Kupffer cells of cirrhotic rats. The application of ET-1 to Kupffer cells induced PAF synthesis in a concentration-dependent manner in both cirrhotic and normal rats via ETB receptor, but PAF synthesis in the activated Kupffer cells was more effective than that in the normal Kupffer cells. In activated Kupffer cells, PAF receptor expression and PAF binding capacity were markedly enhanced. Activated Kupffer cells raised the [125I]-ET-1 binding capacity, but changed neither the affinity of the receptors, nor the expression of ETA receptor. CONCLUSION:Kupffer cells in the course of CCl4-induced cirrhosis are the main source of increased PAF. ET-1 is involved endogenously in stimulating the PAF synthesis in activated Kupffer cells via ETB receptor by paracrine. ETA receptor did not appear in activated Kupffer cells, which may exacerbate the hepatic and extrahepatic complications of cirrhosis.
基金the National Natural Science Foundation of China,No.39290700.
文摘INTRODUCTION Previous clinical and experimental studies haveindicated that an early endotoxemia occurred after amajor burn.It is unlikely that burn wound sepsis isthe source of circulating endotoxin in less than 12hour after burn.Increasing evidence demonstratesthat the bacteria and endotoxin in thegastrointestinal tract can pass through the gutbarrier into blood circulation to form enterogenicendotoxemia following burn.However。
文摘Since its discovery nearly thirty years ago, platelet-activating factor has emerged as one of the more important lipidmediators known. Platelet-activating factor (PAF; 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphorylcholine) exists en-dogenously as a mixture of molecular species with structural variants of the alkyl moiety. PAF is a novel potent signal-ing phospholipid that has unique pleiotropic biological properties in addition to platelet activation. PAF also plays a sig-nificant role in reproduction. PAF content in squirrel monkey sperm is significantly higher during the breeding seasonthan the non-breeding season. PAF content in human sperm has a positive correlation with seminal parameters and preg-nancy outcomes. High-fertility boars have significantly more PAF in their sperm than low-fertility boars. The enzymes(lyso-PAF-acetyltransferase and PAF-acetylhydrolase) necessary for PAF activation and deactivation are present insperm. PAF-acetylhydrolase may act as a 'decapacitation factor'. Removal of this enzyme during capacitation maypromote PAF synthesis increasing motility and fertilization. PAF also plays a significant role in the fertilization process,enhancing the fertilization rates of oocytes. Enhanced embryo development has also been reported in oocytes fertilizedwith PAF-treated sperm. PAF antagonists inhibit sperm motility, acrosome reaction, and fertilization, thus suggestingthe presence of receptors for PAF. The PAF-receptor is present on sperm, with altered transcript levels and distributionpatterns on abnormal cells. Whereas the exact mechanism of PAF in sperm function and reproduction is uncertain, itsimportance in normal fertility is substantial. The reproductive significance of PAF activity in sperm and fertility plus therole of PAF in the establishment of pregnancy requires further study.
基金The Key Scientific and Technological ResearchFoundation of the National 863 Program, No. 2003AA208106Medical Outstandard Foundation of Army, No. 04J020
文摘AIM: To determine platelet activating factor (PAF) receptor expression in cirrhotic hepatic stellate cells.METHODS: Hepatic stellate cells, isolated from the livers of control and CCl4-induced cirrhotic rats, were placed in serum-free medium after overnight culture. We determined the PAF receptor in hepatic stellate cells by saturation binding technique and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and the effects of PAF and its antagonist BN52021 on prostaglandin E2 (PGE2) release by stellate cells.RESULTS: Scatchard analysis indicated the presence of PAF receptor with dissociation constant (Kd) of 4.66 nmol/L and maximum binding capacity (Bmax) of 24.65 fmol/μg in cirrhotic stellate cells. Compared with the control, the maximum PAF binding capacity increased significantly (Bmax: 24.65 ± 1.96 fmol/μg. DNA, R = 0.982 vs 5.74 ± 1.55 fmol/μg. DNA, R = 0.93; P < 0.01), whereas receptor affinity had no significant difference (Kd of 4.66 ± 0.33 nmol/L for the cirrhosis and 3.51 ± 0.26 nmol/L for the control; P > 0.05). Consistent with the receptor binding data, the mRNA expression of PAF receptor was increased significantly in cirrhotic stellate cells. PAF in a concentration-dependent manner induced PGE2 synthesis in cirrhotic hepatic stellate cells, but the effects were blocked significantly by BN52021.CONCLUSION: Cirrhosis sensitizes hepatic stellate cells to PAF by elevating its receptor level and hepatic stellate cells maybe potential effectors of PAF induced portal hypertension.
基金supported by the National Natural Science Foundation of China,No.30471934
文摘Traumatic brain injury causes gene expression changes in different brain regions. Occurrence and development of traumatic brain injury are closely related, involving expression of three factors, namely cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. However, little is known about the correlation of these three factors and brain neuronal injury. In this study, primary cultured rat hippocampal neurons were subjected to fluid percussion injury according to Scott’s method, with some modifications. RT-PCR and semi-quantitative immunocytochemical staining was used to measure the expression levels of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. Our results found that cyclooxygenase-2 expression were firstly increased post-injury, and then decreased. Both mRNA and protein expression levels reached peaks at 8 and 12 hours post-injury, respectively. Similar sequential changes in glutamate receptor 2 were observed, with highest levels mRNA and protein expression at 8 and 12 hours post-injury respectively. On the contrary, the expressions of platelet activating factor receptor were firstly decreased post-injury, and then increased. Both mRNA and protein expression levels reached the lowest levels at 8 and 12 hours post-injury, respectively. Totally, our findings suggest that these three factors are involved in occurrence and development of hippocampal neuronal injury.
文摘Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart disease. Methods: To measure PAF levels in 100 controls, 23 elderly patients with cerebral infarction and 65 cases with coronary heart disease by reversed phase high-performance liquid chromatographic technique (rHPLC). Results:rHPLC is more convenient, sensitive,specific, and less confusing, compared with bio-assay. The level of plasma PAF in patients with cerebral infarction was higher than that in the controls (P<0.01), and in patients with coronary heart disease. Conclusion: Detection of PAF with rHPLC is more reliable and more accurate. The new assay has important significance in PAF research.
基金Supported by The National Natural Science Foundation of China,No.81173393the Natural Science Foundation of Tianjin City,Grant No.12YFJZJC00800+1 种基金the Scientific Research Foundation for PhD grant to Xia SH,No.WYB201010the Innovation Team Program(WHTD201310)from the Logistics University of the Chinese People's Armed Police Force
文摘AIM: To determine the effects of BN52021 on platelet-activating factor receptor (PAFR) signaling molecules under lipopolysaccharide (LPS)-induced inflammatory conditions in MS1 cells. METHODS: MS1 cells (a mouse pancreatic islet endothelial cell line) were grown in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum, 2 mmol/L glutamine and 100 μg/mL penicillin/streptomycin in 5% CO 2 at 37 ℃. After growth to confluency in media, the cells were processed for subsequent studies. The MS1 cells received 0, 0.1, 1 and 10 μg/mL LPS in this experiment. The viability/prolifera-tion of the cells induced by LPS was observed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. Apoptosis and necrosis of the cells under the inflammatory condition described previously were observed using Hoechst 33342-propidium iodide staining. Adenylate cyclase (AC), phospholipase A 2 (PLA 2 ), phospholipase Cβ (PLCβ), protein tyrosine kinase (PTK), G protein-coupled receptor kinases (GRK) and p38-mitogen-activated protein kinase (p38 MAPK) mRNA in the PAFR signaling pathway were measured by real-time polymerase chain reaction. The protein expression level of phosphorylated AC (p-AC), phosphorylated PLA 2 (p-PLA 2 ), phosphorylated PTK (p-PTK), phosphorylated p38 MAPK (p-p38 MAPK), PLCβ and GRK was measured using Western blotting analysis. RESULTS: The activity of MS1 cells incubated with dif- ferent concentrations of LPS for 6 h decreased significantly in the 1 μg/mL LPS group (0.49 ± 0.10 vs 0.67 ± 0.13, P < 0.05) and 10 μg/mL LPS group (0.44 ± 0.10 vs 0.67 ± 0.13, P < 0.001), but not in 0.1 μg/mL group. When the incubation time was extended to 12 h (0.33 ± 0.05, 0.32 ± 0.03 and 0.25 ± 0.03 vs 0.69 ± 0.01) and 24 h (0.31 ± 0.01, 0.29 ± 0.03 and 0.25 ± 0.01 vs 0.63 ± 0.01), MS1 cell activity decreased in all LPS concentration groups compared with the blank control (P < 0.001). BN52021 significantly improved the cell activity when its concentration reached 50 μmol/L compared with the group that received LPS treatment alone, which was consistent with the results obtained from fluorescence staining. The mRNAs levels of AC (4.02 ± 0.14 vs 1.00 ± 0.13), GRK (2.63 ± 0.03 vs 1.00 ± 0.12), p38 MAPK (3.87 ± 0.07 vs 1.00 ± 0.17), PLA 2 (3.31 ± 0.12 vs 1.00 ± 0.12), PLCβ (2.09 ± 0.08 vs 1.00 ± 0.06) and PTK (1.85 ± 0.07 vs 1.00 ± 0.11) were up-regulated after LPS stimulation as compared with the blank control (P < 0.05). The up- regulated mRNAs including AC (2.35 ± 0.13 vs 3.87 ± 0.08), GRK (1.17 ± 0.14 vs 2.65 ± 0.12), p38 MAPK (1.48 ± 0.18 vs 4.30 ± 0.07), PLCβ (1.69 ± 0.10 vs 2.41 ± 0.13) and PLA 2 (1.87 ± 0.11 vs 2.96 ± 0.08)were significantly suppressed by BN52021 except for that of PTK. The level of p-AC (1.11 ± 0.12 vs 0.65 ± 0.08), GRK (0.83 ± 0.07 vs 0.50 ± 0.03), PLCβ (0.83 ± 0.16 vs 0.50 ± 0.10) and p-p38 MAPK (0.74 ± 0.10 vs 0.38 ± 0.05) was up-regulated after LPS stimulation as compared with the blank control (P < 0.05). The up-regulated proteins, including p-AC (0.65 ± 0.15 vs 1.06 ± 0.14), GRK (0.47 ± 0.10 vs 0.80 ± 0.06), PLCβ (0.47 ± 0.04 vs 0.80 ± 0.19) and p-p38 MAPK (0.30 ± 0.10 vs 0.97 ± 0.05), was significantly suppressed by BN52021, but p-PLA 2 and p-PTK protein level were not suppressed. CONCLUSION: BN52021 could effectively inhibit LPS-induced inflammation by down-regulating the mRNA and protein levels of AC, GRK, p38 MAPK, PLA 2 and PLCβ in the PAFR signaling pathway.
基金Beijing Natural Science Foundation,Grant/Award Number:L222145CAMS Innovation Fund for Medical Sciences,Grant/Award Number:2019-I2M-5-038+2 种基金Clinical Medicine Plus X-Young Scholars Project,Peking Universitythe Fundamental Research Funds for the Central Universities,Grant/Award Number:PKU2023LCXQ017National Natural Science Foundation of China,Grant/Award Number:81700935。
文摘Background:The effect of platelet factor 4(PF4)on bone marrow mesenchymal stem cells(BMMSCs)and osteoporosis is poorly understood.Therefore,this study aimed to evaluate the effects of PF4-triggered bone destruction in mice and determine the underlying mechanism.Methods:First,in vitro cell proliferation and cell cycle of BMMSCs were assessed using a CCK8 assay and flow cytometry,respectively.Osteogenic differentiation was confirmed using staining and quantification of alkaline phosphatase and Alizarin Red S.Next,an osteoporotic mouse model was established by performing bilateral ovariectomy(OVX).Furthermore,the PF4 concentrations were obtained using enzymelinked immunosorbent assay.The bone microarchitecture of the femur was evaluated using microCT and histological analyses.Finally,the key regulators of osteogenesis and pathways were investigated using quantitative real-time polymerase chain reaction and Western blotting.Results:Human PF4 widely and moderately decreased the cell proliferation and osteogenic differentiation ability of BMMSCs.Furthermore,the levels of PF4 in the serum and bone marrow were generally increased,whereas bone microarchitecture deteriorated due to OVX.Moreover,in vivo mouse PF4 supplementation triggered bone deterioration of the femur.In addition,several key regulators of osteogenesis were downregulated,and the integrinα5-focal adhesion kinase-extracellular signalregulated kinase(ITGA5-FAK-ERK)pathway was inhibited due to PF4 supplementation.Conclusions:PF4 may be attributed to OVX-i nduced bone loss triggered by the suppression of bone formation in vivo and alleviate BMMSC osteogenic differentiation by inhibiting the ITGA5-FAK-ERK pathway.
文摘A simple and rapid method was established to study vascular permeability by in vitroperfused endothelial cell monolayers cultured on micropore filter membrane.It can be used todetermine filtration coefficient (K<sub>f</sub>) to small molecules and osmotic reflection coefficient (σ) toproteins of the endothelial monolayer.Hanks’ balanced salt solution (HBSS) or 5g/L albuminin HBSS was used to perfuse the confluent endothelial monolayer at the hydrostatic pressure of2.45kPa (25cm H<sub>2</sub>O).Control K<sub>f</sub> values were 10.1±0.75 and 3.6±0.75μl·min<sup>-1</sup>·cm<sup>-2</sup>·kPa(-1)(±,n=3) respectively for the perfusion of HBSS and albumin HBSS,suggesting that al-bumin may decrease endothelial monolayer permeability to water and small molecules.After ex-posure of endothelial monolayer to 10<sup>-8</sup>mol/L platelet-activating factor (PAF) for 30min,K<sub>f</sub>values increased to 193.1% and 133.3% respectively.Protein clearance rate (μl.min<sup>-1</sup>·cm<sup>-2</sup>)and osmotic reflection coefficient of the control endothelial monolayer were 8.0±3.22 and 0.37±0.09 respectively and those of the PAF treated endothelial monolayer 12.2±2.95μl·min<sup>-1</sup>·cm<sup>-2</sup> and 0.18±0.06,revealing increased permeability to albumin.Computer-assisted imageprocessing demonstrated that PAF treatment decreased cell area while increased cell form factorand intercellular space,suggesting that endothelial cells retracted and rounded,which may bean important mechanism of PAF-induced increase of vascular permeability.
基金the Grant from Scientific Planning Program of Guangdong Province, No.2004B36001009Scientific Research Funds of Guangdong Bureau of Traditional Chinese Medicine,No.30002+1 种基金Scientific Development Planning Funds of Foshan City, No.200124 Medical Scientific Research Program of Foshan City, No.2000096
文摘BACKGROUND: Pharmacologic action of traditional Chinese medicine compound is the comprehensive effect of various ingredients, and the interactions of various ingredients are closely correlated with the final effect. In order to reveal the compatibility mechanism of buyang huanwu decoction (BHD)'s prescription in treating and preventing ischemic cerebrovascular disease, we need to explore the effect and relation of ingredients in prescription except for considering the effect of each ingredient on the whole prescription. OBJECTIVE: To study the effect of BHD and its ingredients in the prescription on the specific binding of 3H-platelet activating factor (PAF) to its receptor (PAFR)in rabbits in vitro, and to analyze the action of each ingredient in the prescription. DESIGN: A decomposed recipe study based on orthogonal test. SETTING: Guangzhou University of Traditional Chinese Medicine. MATERIALS: Five healthy adult New Zealand rabbits of either gender were provided by the Experimental Animal Center of Guangzhou University of Traditional Chinese medicine. The prescription herbal pieces were purchased from Foshan Kangpu Pharmaceuticals Company and Jianmin Pharmaceuticals Company, and were appraised by Professor Yanchen Xu from College of Traditional Chinese Medicine, Guangzhou University of Traditional Chinese Medicine. 3H-PAF was supplied by Amersham Co,Ltd.(Specific activity: 6.475 TBq/mmol;batch number:200402); PAF standard by Biomol Co., Ltd.(batch number: P1318V). METHODS: This experiment was carried out in the Laboratory of Nuclear Medicine, Guangzhou University of Traditional Chinese Medicine between September and December 2004. ①The seven influencing factors were selected: such as Shenghuangqi , Dangguiwei, Chishao, Dilong, Taoren, Honghua, Chuanxiong. Each factor was divided into two levels, selected or not selected. The tests were arranged according to L8 (27) orthogonal test table. ②The specific binding of 3H-PAF to its receptors in rabbits was measured by radioligand binding assay. The inhibitory rate of the specific binding was used as an assessing index. The inhibitory action of and on 3H-PAF to PAFR binding was analyzed and compared in vitro. The inhibitory action of each ingredient in the prescription BHD on 3H-PAF to PAFR binding was investigated and compared in vitro by direct analysis and analysis of variance of orthogonal test. MAIN OUTCOME MEASURES: Effect of 8 prescriptions for L8 (27) orthogonal test table on the specific binding inhibition rate of 3H-PAF and PAFR. RESULTS: According to results of variance analysis of orthogonal test, the inhibitory action of each ingredient in the prescription BHD on 3H-PAF to PAFR binding from the highest to the lowest was in turn Honghua, ShenghuangqL Taoren, Dilong, DangguiweL Chuanxiong, Chishao. Honghua, Shenghuangqi, Taoren, Dilong, Danguiwei were major influence factors to 3H-PAF to PAFR in rabbits (F = 187.829,144.446,59.521,5.018,4.265, P 〈 0.05- 0.01), but Chuanxiong and Chishao had not obviously inhibitory effect. The specific binding inhibition rate of prescriptions (except Shenghuangqi ) was obviously higher than that of one of prescriptions (Shenghuangqi included). CONCLUSION: The results of orthogonal test show that Honghua, ShenghuangqL Taoren, Dilong, Dangguiwei are major influencing factors to inhibit binding of sH-PAF to PAFR in rabbits, among which, Honghua is the strongest in ingredients of prescription BHD. The results also reveal that Shenghuangqi is able to weaken the inhibitory effect and to prevent the strong inhibitory effect of blood-activating drugs in BHD.
文摘Effect of platelet activating factor(PAF) on blood spinal cord barrier in cervical cord injury was investigated. Methods: Spinal cord injury at C6 segment was induced with Allen’s ’method in cats. PAF and PAF receptor antagonist BN52021 were administered by arachnoid space and intravenous injection respectively, and their effects on PAF levels, blood spinal cord barrier and cervical cord edema in the injuried zone and adjacent cervical cord tissue following cervical cord injury were investigated. Results: PAF levels, Evens content and water content in the injuried and adjacent cervical cord tissues significantly increased following trauma. PAF levels, Evens content and water content were evidently elevated with PAF by arachnoid space injection. PAF receptor antagonist BN52021 could inhibit the increase in PAF levels and reduce Evens and water content in the cervical cord tissue following trauma. Conclusion: PAF is an important contributing factor causing post-traumatic damage to the blood spinal cord barrier, while PAF receptor antagonist can effectively relieve post-traumatic damage to the blood spinal cord barrier.