AIM:To study the protein C activation system in human liver myofibroblasts,and the effects of activated protein C(APC)on these cells.METHODS:Human liver myofibroblasts were obtained by outgrowth.Expression of protease...AIM:To study the protein C activation system in human liver myofibroblasts,and the effects of activated protein C(APC)on these cells.METHODS:Human liver myofibroblasts were obtained by outgrowth.Expression of protease activated receptor 1(PAR-1),endothelial protein C receptor(EPCR) and thrombomodulin(TM)was analyzed by flow cytometry.Extracellular signal-regulated kinase(ERK)1/2 activation was assessed by Western blotting using anti-phospho-ERK antibodies.Collagen synthesis was studied with real-time reverse transcription-polymerase chain reaction(RT-PCR).Activation of protein C was studied by incubating liver myofibroblasts with zymogen protein C in the presence of thrombin and detecting the generation of APC with a colorimetric assay using a peptide substrate. RESULTS:Primary cultures of human liver myofibroblasts expressed EPCR on their surface,together with PAR-1 and TM.This receptor system was functional since exposure of myofibroblasts to APC inducedERK1/2 phosphorylation in a dose-and time-dependent manner.Furthermore,APC significantly upregulated the expression of collagen mRNA,as shown by real-time RT-PCR.Collagen upregulation was controlled through the ERK pathway as it was inhibited when using the mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor PD98059.Finally,using a cell-based colorimetric assay,we showed that intact myofibroblasts converted protein C into APC in the presence of thrombin.CONCLUSION:These data suggest that APC is a new modulator of liver myofibroblast activity and contributes to the pathophysiology of chronic liver diseases.展开更多
Objective： To investigate the neuro-protective effects of baicaiin in Wistar rats with focal cerebral ischemic reperfusion injury. Methods： Ninety adult male Wistar rats weighing 320-350 g were randomly divided into...Objective： To investigate the neuro-protective effects of baicaiin in Wistar rats with focal cerebral ischemic reperfusion injury. Methods： Ninety adult male Wistar rats weighing 320-350 g were randomly divided into the following groups （n=5）： （a） sham control group; （b） vehicle group, subjected to middle cerebral artery occlusion and received vehicle intraperitoneally; （c-e） baicalin groups, which were subjected to the middle cerebral artery occlusion and treated with baicalin 25, 50 and 100 mg/kg, respectively. The neurological scores were determined at postoperative 1, 3 and 7 d after the treatment. The expression of protease-activated receptor-1 （PAR-1）, PAR-1 mRNA and Caspase-3 were determined using Western blot, reverse transcription polymerase chain reaction （RT- PCR） analysis and immunohistochemistry, respectively. Results： Significant decrease was noted in the neurological score in the baicalin group compared with that of the vehicle group （P〈0.01）. Additionally, down-regulation of PAR-1 mRNA, PAR-1 and Caspase-3 was observed in the baicalin groups compared with those obtained from the vehicle group （P〈0.01）. Compared with the low-dose baicalin group （25 mg/kg）, remarkable decrease was noted in neurological score, and the expression of PAR-1 mRNA, PAR-1 as well as Caspase-3 in the high-dose group （P〈0.05）. Conclusion： Baicalin showed neuro-protective effects in focal cerebral ischemic reperfusion injury through inhibiting the expression of PAR-1 and apoptosis.展开更多
Hippocampal neurons were treated by thrombin and thrombin receptor activatingpeptides (TRAP). Cell survival rate was decreased in a dose-dependent manner by MTT assay. Thenumbers of apoptotic cell and apoptotic rate o...Hippocampal neurons were treated by thrombin and thrombin receptor activatingpeptides (TRAP). Cell survival rate was decreased in a dose-dependent manner by MTT assay. Thenumbers of apoptotic cell and apoptotic rate of hippocampal neurons treated bydifferentconcentrations of thrombin were increased in a dose-dependent manner by terminal deoxynucleotidyltransferase (TdT) mediated dUTP-biotin nick end-labeling (TUNED method and Flow Cytometry. When theconcentration of thrombin is 40 U/mL, TUNEL positive cells and apoptotic rate of hippocampal neuronsreached peak value, were 27. 3 +- 4. 0 and (29. 333 +- 4. 633 ) % , respectively.Immunocytochemistry assay show that Bcl-2 protein expression was down- regulated and Bax proteinexpression was up-regulated with the concentration of thrombin increased. TRAP can mimic the effectof thrombin to induce apoptosis on hippocampal neurons. These data demonstrated that thrombininduced hippocampal neuron apoptosis in a dose-dependent manner through activatingprotease-acti-vated protein-1 (PAR-1). The change in expression of Bcl-2 and Bax was related withthe effect of high concentration thrombin induced apoptosis on hippocampal neurons.展开更多
This study examined the expression of connexin and protease-activated receptor 3 （par-3） in the distal resection margin of rectal cancer and the correlation of the expression of the two proteins with tumor relapse. ...This study examined the expression of connexin and protease-activated receptor 3 （par-3） in the distal resection margin of rectal cancer and the correlation of the expression of the two proteins with tumor relapse. A total of 40 patients with rectal cancer underwent ultra-low anterior resection with curved cutter stapler. The pathological specimens were divided into 3 groups in terms of sampling sites： tumor group, 2.0-cm group （in which the tissues were harvested 2.0 cm distal to the tumor tissues）, 3.0-cm group （in which the tissues were taken 3.0 cm away from the tumor tissues）. All the samples were pathologically observed and then measured for the expression of connexin and par-3 by employing immunohistochemistry and Western blotting. The operations in this series went uneventfully. No anastomotic stoma bleeding, stenosis and death occurred postoperatively. Histopathologically, in the tumor group, epithelial cells lost normal pattern of arrangement and polarity, and were loosely connected and even detached. In the 3.0-cm group, the epithelia had normal appearance, obvious cell polarity and essentially intact cell junction. Immunohistochemistry and Western blotting indicated that the 3.0-cm group had the strongest expression of connexin and par-3, and the expression in the 2.0-cm group and the tumor group was relatively weak. There existed significant difference in the expression of the two proteins among the three groups （P〈0.05 for all）. It was concluded that the down-regulated connexin and par-3 in the distal margin of rectal cancer tissues may indicate the progression of the disease and high likelihood of recurrence and metastasis. Although no tumor cells were found in the sections of the 2.0cm group, the decreased expression of connexin and par-3 may suggest the development of anaplasia and the increased odds of tumor relapse. Therefore, we are led to speculate that tumor resection only including 2.0 cm of unaffected rectum could not completely avoid the distant metastasis and local re展开更多
Objective:To clarify the active constituents of the heartwoods of Caesalpinia sappan,a traditional Chinese medicine with the functions of promoting blood circulation(Huoxue in Chinese)and removing blood stasis(Quyu in...Objective:To clarify the active constituents of the heartwoods of Caesalpinia sappan,a traditional Chinese medicine with the functions of promoting blood circulation(Huoxue in Chinese)and removing blood stasis(Quyu in Chinese).Methods:The chemical constituents were isolated and purified by combination of silica gel and Sephadex LH-20 column chromatography,along with semipreparative HPLC.Their chemical structures were established by multiple spectroscopic methods and comparison with literature data.The in vitro antiplatelet aggregation activities were evaluated using mouse platelet induced by AYPGKF-NH2,a gold agonist of protease-activated receptor 4(PAR4).Results:Two new phenols,methyl 2-(4,4’,5’-trihydroxy-2’-(methoxymethyl)biphenyl-2-yloxy)acetate(1)and 1’-methylcaesalpin J(2),together with 24 known compounds(3-26),were isolated from the heartwoods of C.sappan.Among them,sappanchalcone(16)and brazilin(20)showed inhibitory activities against mouse platelet aggregation with IC50 values of 114.8μmol/L and 100.8μmol/L,respectively.Conclusion:Antiplatelet compounds from C.sappan targeting at PAR4 are reported for the first time.展开更多
Cerebral ischemia/reperfusion injury is partially mediated by thrombin, which causes brain damage through protease-activated receptor 1（PAR1）. However, the role and mechanisms underlying the effects of PAR1 activati...Cerebral ischemia/reperfusion injury is partially mediated by thrombin, which causes brain damage through protease-activated receptor 1（PAR1）. However, the role and mechanisms underlying the effects of PAR1 activation require further elucidation. Therefore, the present study investigated the effects of the PAR1 antagonist SCH79797 in a rabbit model of global cerebral ischemia induced by cardiac arrest. SCH79797 was intravenously administered 10 minutes after the model was established. Forty-eight hours later, compared with those administered saline, rabbits receiving SCH79797 showed markedly decreased neuronal damage as assessed by serum neuron specific enolase levels and less neurological dysfunction as determined using cerebral performance category scores. Additionally, in the hippocampus, cell apoptosis, polymorphonuclear cell infiltration, and c-Jun levels were decreased, whereas extracellular signal-regulated kinase phosphorylation levels were increased. All of these changes were inhibited by the intravenous administration of the phosphoinositide 3-kinase/Akt pathway inhibitor LY29004（3 mg/kg） 10 minutes before the SCH79797 intervention. These findings suggest that SCH79797 mitigates brain injury via anti-inflammatory and anti-apoptotic effects, possibly by modulating the extracellular signal-regulated kinase, c-Jun N-terminal kinase/c-Jun and phosphoinositide 3-kinase/Akt pathways.展开更多
Background Previous studies have indicated that thrombi n (TM) may play a major role in brain edema after intracerebral hemorrhages (ICHs). However, the mechanism of TM-induced brain edema is poorly understood. In th...Background Previous studies have indicated that thrombi n (TM) may play a major role in brain edema after intracerebral hemorrhages (ICHs). However, the mechanism of TM-induced brain edema is poorly understood. In this study, we explored the effect of TM on the permeability of the blood brain barrier (BBB) and investigated its possible mechanism, aiming at providing a potential target for brain edema therapy after ICHs.Methods TM or TM + cathepsin G (CATG) was stereotaxically injected into the right caudate nucleus of Sprague-Dawley rats in vivo. BBB permeability was measured by Evans-Blue extravasation. Brain water content was determined by the dry-wet weight method. Brain microvascular endothelial cells were then cultured in vitro. After TM or TM+CATG was added to the endothelial cell medium, changes in the morphology of cells were dynamically observed by phase-contrast light microscopy, and the expression of matrix metalloproteinase-2 (MMP-2) protein was measured by immunohistochemical method.Results BBB permeability increased at 6 hours after a TM injection into the ipsilateral caudate nucleus (P<0.05), peaked between 24 hours (P<0.01) and 48 hours (P<0.05) after the injection, and then declined. Brain water content changed in parallel with the changes in BBB permeability. However, at all time points, BBB permeability and brain water content after a TM+CATG injection were not significantly different from the respective parameters in the control group (P>0.05). TM induced endothelial cell contraction in vitro in a time-dependent manner and enhanced the expression of MMP-2 protein. After incubation with TM+CATG, cell morphology and MMP-2 expression did not change significantly as compared to the control group (P>0.05).Conclusions Increased BBB permeability may be one of the mechanisms behind TM-induced cerebral edema. TM induces endothelial cell contraction and promotes MMP-2 expression by activating protease activated receptor-1 (PAR-1), possibly leading to the opening of the BBB.展开更多
Summary: In order to explore the PAR-1 mRNA and protein expression around hemotoma following intracerebral hemorrhage and the relation between the PAR-1 expression and thrombin, collagenase Ⅶ was stereotaxically inje...Summary: In order to explore the PAR-1 mRNA and protein expression around hemotoma following intracerebral hemorrhage and the relation between the PAR-1 expression and thrombin, collagenase Ⅶ was stereotaxically injected into right caudate nucleus in rats. The PAR-1 mRNA expression was detected by RT-PCR method and the PAR-1 protein expression by immunohistochemical method respectively. It was found that the PAR-1 mRNA and protein expression around hemotoma was increased at 6 h after intracerebral hemorrhage (P<0.05), peaked at 2 days (P<0.01), and then declined. The change pattern of the PAR-1 mRNA and protein expression was similar to that of intracerebral hemorrhage after thrombin intracerebral injection. The PAR-1 mRNA and protein expression in hirudin group showed no significant difference with control group. These results indicated that the PAR-1 mRNA and protein expression were markedly increased after intracerebral hemorrhage, which may be closely related to thrombin. Upregulation of the PAR-1 expression may involve in neurotoxic injury induced by thrombin.展开更多
The neuro-glial interface extends far beyond mechanical support alone and includes interactions through coagulation cascade proteins. Here, we systematically review the evidence indicating that synaptic and node of Ra...The neuro-glial interface extends far beyond mechanical support alone and includes interactions through coagulation cascade proteins. Here, we systematically review the evidence indicating that synaptic and node of Ranvier glia cell components modulate synaptic transmission and axonal conduction by a coagulation cascade protein system, leading us to propose the concept of the neuro-glial coagulonome. In the peripheral nervous system, the main thrombin receptor protease activated receptor 1 (PAR1) is located on the Schwann microvilli at the node of Ranvier and at the neuromuscular junction. PAR1 activation effects can be both neuroprotective or harmful, depending on thrombin activity levels. Low physiological levels of thrombin induce neuroprotective effects in the Schwann cells which are mediated by the endothelial protein C receptor. High levels of thrombin induce conduction deficits, as found in experimental autoimmune neuritis, the animal model for Guillaine-Barre syndrome. In the central nervous system, PAR1 is located on the peri-synaptic astrocyte end-feet. Its activation by high thrombin levels is involved in the pathology of primary inflammatory brain diseases such as multiple sclerosis, as well as in other central nervous system insults, including trauma, neoplasms, epilepsy and vascular injury. Following activation of PAR1 by high thrombin levels the seizure threshold is lowered. On the other hand, PAR1 activation by lower levels of thrombin in the central nervous system protects against a future ischemic insult. This review presents the known structure and function of the neuro-glial coagulonome, focusing on coagulation, thrombin and PAR1 in a pathway which may be either physiological (neuroprotective) or detrimental in peripheral nervous system and central nervous system diseases. Understanding the neuro-glial coagulonome may open opportunities for novel pharmacological interventions in neurological diseases.展开更多
文摘AIM:To study the protein C activation system in human liver myofibroblasts,and the effects of activated protein C(APC)on these cells.METHODS:Human liver myofibroblasts were obtained by outgrowth.Expression of protease activated receptor 1(PAR-1),endothelial protein C receptor(EPCR) and thrombomodulin(TM)was analyzed by flow cytometry.Extracellular signal-regulated kinase(ERK)1/2 activation was assessed by Western blotting using anti-phospho-ERK antibodies.Collagen synthesis was studied with real-time reverse transcription-polymerase chain reaction(RT-PCR).Activation of protein C was studied by incubating liver myofibroblasts with zymogen protein C in the presence of thrombin and detecting the generation of APC with a colorimetric assay using a peptide substrate. RESULTS:Primary cultures of human liver myofibroblasts expressed EPCR on their surface,together with PAR-1 and TM.This receptor system was functional since exposure of myofibroblasts to APC inducedERK1/2 phosphorylation in a dose-and time-dependent manner.Furthermore,APC significantly upregulated the expression of collagen mRNA,as shown by real-time RT-PCR.Collagen upregulation was controlled through the ERK pathway as it was inhibited when using the mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor PD98059.Finally,using a cell-based colorimetric assay,we showed that intact myofibroblasts converted protein C into APC in the presence of thrombin.CONCLUSION:These data suggest that APC is a new modulator of liver myofibroblast activity and contributes to the pathophysiology of chronic liver diseases.
基金Supported by National Natural Science Foundation of China(No.81072916)Shandong Science and Technique Foundation(No.2005GG3202062)+1 种基金Shandong Traditional Chinese Medicine Administration Fund Program(No.2009-160)Free Exploration Program of Shandong University(No.2009TS009)
文摘Objective： To investigate the neuro-protective effects of baicaiin in Wistar rats with focal cerebral ischemic reperfusion injury. Methods： Ninety adult male Wistar rats weighing 320-350 g were randomly divided into the following groups （n=5）： （a） sham control group; （b） vehicle group, subjected to middle cerebral artery occlusion and received vehicle intraperitoneally; （c-e） baicalin groups, which were subjected to the middle cerebral artery occlusion and treated with baicalin 25, 50 and 100 mg/kg, respectively. The neurological scores were determined at postoperative 1, 3 and 7 d after the treatment. The expression of protease-activated receptor-1 （PAR-1）, PAR-1 mRNA and Caspase-3 were determined using Western blot, reverse transcription polymerase chain reaction （RT- PCR） analysis and immunohistochemistry, respectively. Results： Significant decrease was noted in the neurological score in the baicalin group compared with that of the vehicle group （P〈0.01）. Additionally, down-regulation of PAR-1 mRNA, PAR-1 and Caspase-3 was observed in the baicalin groups compared with those obtained from the vehicle group （P〈0.01）. Compared with the low-dose baicalin group （25 mg/kg）, remarkable decrease was noted in neurological score, and the expression of PAR-1 mRNA, PAR-1 as well as Caspase-3 in the high-dose group （P〈0.05）. Conclusion： Baicalin showed neuro-protective effects in focal cerebral ischemic reperfusion injury through inhibiting the expression of PAR-1 and apoptosis.
文摘Hippocampal neurons were treated by thrombin and thrombin receptor activatingpeptides (TRAP). Cell survival rate was decreased in a dose-dependent manner by MTT assay. Thenumbers of apoptotic cell and apoptotic rate of hippocampal neurons treated bydifferentconcentrations of thrombin were increased in a dose-dependent manner by terminal deoxynucleotidyltransferase (TdT) mediated dUTP-biotin nick end-labeling (TUNED method and Flow Cytometry. When theconcentration of thrombin is 40 U/mL, TUNEL positive cells and apoptotic rate of hippocampal neuronsreached peak value, were 27. 3 +- 4. 0 and (29. 333 +- 4. 633 ) % , respectively.Immunocytochemistry assay show that Bcl-2 protein expression was down- regulated and Bax proteinexpression was up-regulated with the concentration of thrombin increased. TRAP can mimic the effectof thrombin to induce apoptosis on hippocampal neurons. These data demonstrated that thrombininduced hippocampal neuron apoptosis in a dose-dependent manner through activatingprotease-acti-vated protein-1 (PAR-1). The change in expression of Bcl-2 and Bax was related withthe effect of high concentration thrombin induced apoptosis on hippocampal neurons.
文摘This study examined the expression of connexin and protease-activated receptor 3 （par-3） in the distal resection margin of rectal cancer and the correlation of the expression of the two proteins with tumor relapse. A total of 40 patients with rectal cancer underwent ultra-low anterior resection with curved cutter stapler. The pathological specimens were divided into 3 groups in terms of sampling sites： tumor group, 2.0-cm group （in which the tissues were harvested 2.0 cm distal to the tumor tissues）, 3.0-cm group （in which the tissues were taken 3.0 cm away from the tumor tissues）. All the samples were pathologically observed and then measured for the expression of connexin and par-3 by employing immunohistochemistry and Western blotting. The operations in this series went uneventfully. No anastomotic stoma bleeding, stenosis and death occurred postoperatively. Histopathologically, in the tumor group, epithelial cells lost normal pattern of arrangement and polarity, and were loosely connected and even detached. In the 3.0-cm group, the epithelia had normal appearance, obvious cell polarity and essentially intact cell junction. Immunohistochemistry and Western blotting indicated that the 3.0-cm group had the strongest expression of connexin and par-3, and the expression in the 2.0-cm group and the tumor group was relatively weak. There existed significant difference in the expression of the two proteins among the three groups （P〈0.05 for all）. It was concluded that the down-regulated connexin and par-3 in the distal margin of rectal cancer tissues may indicate the progression of the disease and high likelihood of recurrence and metastasis. Although no tumor cells were found in the sections of the 2.0cm group, the decreased expression of connexin and par-3 may suggest the development of anaplasia and the increased odds of tumor relapse. Therefore, we are led to speculate that tumor resection only including 2.0 cm of unaffected rectum could not completely avoid the distant metastasis and local re
基金supported by the International Partnership Program of Chinese Academy of Sciences(153631KYSB20160004)the Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(Y4ZK111B01).
文摘Objective:To clarify the active constituents of the heartwoods of Caesalpinia sappan,a traditional Chinese medicine with the functions of promoting blood circulation(Huoxue in Chinese)and removing blood stasis(Quyu in Chinese).Methods:The chemical constituents were isolated and purified by combination of silica gel and Sephadex LH-20 column chromatography,along with semipreparative HPLC.Their chemical structures were established by multiple spectroscopic methods and comparison with literature data.The in vitro antiplatelet aggregation activities were evaluated using mouse platelet induced by AYPGKF-NH2,a gold agonist of protease-activated receptor 4(PAR4).Results:Two new phenols,methyl 2-(4,4’,5’-trihydroxy-2’-(methoxymethyl)biphenyl-2-yloxy)acetate(1)and 1’-methylcaesalpin J(2),together with 24 known compounds(3-26),were isolated from the heartwoods of C.sappan.Among them,sappanchalcone(16)and brazilin(20)showed inhibitory activities against mouse platelet aggregation with IC50 values of 114.8μmol/L and 100.8μmol/L,respectively.Conclusion:Antiplatelet compounds from C.sappan targeting at PAR4 are reported for the first time.
基金supported by the Natural Science Foundation of Hubei Province of China,No.2010CDB09101
文摘Cerebral ischemia/reperfusion injury is partially mediated by thrombin, which causes brain damage through protease-activated receptor 1（PAR1）. However, the role and mechanisms underlying the effects of PAR1 activation require further elucidation. Therefore, the present study investigated the effects of the PAR1 antagonist SCH79797 in a rabbit model of global cerebral ischemia induced by cardiac arrest. SCH79797 was intravenously administered 10 minutes after the model was established. Forty-eight hours later, compared with those administered saline, rabbits receiving SCH79797 showed markedly decreased neuronal damage as assessed by serum neuron specific enolase levels and less neurological dysfunction as determined using cerebral performance category scores. Additionally, in the hippocampus, cell apoptosis, polymorphonuclear cell infiltration, and c-Jun levels were decreased, whereas extracellular signal-regulated kinase phosphorylation levels were increased. All of these changes were inhibited by the intravenous administration of the phosphoinositide 3-kinase/Akt pathway inhibitor LY29004（3 mg/kg） 10 minutes before the SCH79797 intervention. These findings suggest that SCH79797 mitigates brain injury via anti-inflammatory and anti-apoptotic effects, possibly by modulating the extracellular signal-regulated kinase, c-Jun N-terminal kinase/c-Jun and phosphoinositide 3-kinase/Akt pathways.
文摘Background Previous studies have indicated that thrombi n (TM) may play a major role in brain edema after intracerebral hemorrhages (ICHs). However, the mechanism of TM-induced brain edema is poorly understood. In this study, we explored the effect of TM on the permeability of the blood brain barrier (BBB) and investigated its possible mechanism, aiming at providing a potential target for brain edema therapy after ICHs.Methods TM or TM + cathepsin G (CATG) was stereotaxically injected into the right caudate nucleus of Sprague-Dawley rats in vivo. BBB permeability was measured by Evans-Blue extravasation. Brain water content was determined by the dry-wet weight method. Brain microvascular endothelial cells were then cultured in vitro. After TM or TM+CATG was added to the endothelial cell medium, changes in the morphology of cells were dynamically observed by phase-contrast light microscopy, and the expression of matrix metalloproteinase-2 (MMP-2) protein was measured by immunohistochemical method.Results BBB permeability increased at 6 hours after a TM injection into the ipsilateral caudate nucleus (P<0.05), peaked between 24 hours (P<0.01) and 48 hours (P<0.05) after the injection, and then declined. Brain water content changed in parallel with the changes in BBB permeability. However, at all time points, BBB permeability and brain water content after a TM+CATG injection were not significantly different from the respective parameters in the control group (P>0.05). TM induced endothelial cell contraction in vitro in a time-dependent manner and enhanced the expression of MMP-2 protein. After incubation with TM+CATG, cell morphology and MMP-2 expression did not change significantly as compared to the control group (P>0.05).Conclusions Increased BBB permeability may be one of the mechanisms behind TM-induced cerebral edema. TM induces endothelial cell contraction and promotes MMP-2 expression by activating protease activated receptor-1 (PAR-1), possibly leading to the opening of the BBB.
基金ThisprojectwassupportedbyagrantfromHainanProvincialNaturalSciencesFoundationofChina (No .30 2 15 ) .
文摘Summary: In order to explore the PAR-1 mRNA and protein expression around hemotoma following intracerebral hemorrhage and the relation between the PAR-1 expression and thrombin, collagenase Ⅶ was stereotaxically injected into right caudate nucleus in rats. The PAR-1 mRNA expression was detected by RT-PCR method and the PAR-1 protein expression by immunohistochemical method respectively. It was found that the PAR-1 mRNA and protein expression around hemotoma was increased at 6 h after intracerebral hemorrhage (P<0.05), peaked at 2 days (P<0.01), and then declined. The change pattern of the PAR-1 mRNA and protein expression was similar to that of intracerebral hemorrhage after thrombin intracerebral injection. The PAR-1 mRNA and protein expression in hirudin group showed no significant difference with control group. These results indicated that the PAR-1 mRNA and protein expression were markedly increased after intracerebral hemorrhage, which may be closely related to thrombin. Upregulation of the PAR-1 expression may involve in neurotoxic injury induced by thrombin.
文摘The neuro-glial interface extends far beyond mechanical support alone and includes interactions through coagulation cascade proteins. Here, we systematically review the evidence indicating that synaptic and node of Ranvier glia cell components modulate synaptic transmission and axonal conduction by a coagulation cascade protein system, leading us to propose the concept of the neuro-glial coagulonome. In the peripheral nervous system, the main thrombin receptor protease activated receptor 1 (PAR1) is located on the Schwann microvilli at the node of Ranvier and at the neuromuscular junction. PAR1 activation effects can be both neuroprotective or harmful, depending on thrombin activity levels. Low physiological levels of thrombin induce neuroprotective effects in the Schwann cells which are mediated by the endothelial protein C receptor. High levels of thrombin induce conduction deficits, as found in experimental autoimmune neuritis, the animal model for Guillaine-Barre syndrome. In the central nervous system, PAR1 is located on the peri-synaptic astrocyte end-feet. Its activation by high thrombin levels is involved in the pathology of primary inflammatory brain diseases such as multiple sclerosis, as well as in other central nervous system insults, including trauma, neoplasms, epilepsy and vascular injury. Following activation of PAR1 by high thrombin levels the seizure threshold is lowered. On the other hand, PAR1 activation by lower levels of thrombin in the central nervous system protects against a future ischemic insult. This review presents the known structure and function of the neuro-glial coagulonome, focusing on coagulation, thrombin and PAR1 in a pathway which may be either physiological (neuroprotective) or detrimental in peripheral nervous system and central nervous system diseases. Understanding the neuro-glial coagulonome may open opportunities for novel pharmacological interventions in neurological diseases.
