Aim： To investigate mechanisms of tryptase-induced reduction of sperm motility and explore whether epidermal growth factor receptor （EGF-R） and protease activated receptor 2 （PAR-2）- associated pathways are invol...Aim： To investigate mechanisms of tryptase-induced reduction of sperm motility and explore whether epidermal growth factor receptor （EGF-R） and protease activated receptor 2 （PAR-2）- associated pathways are involved. Methods： Fresh semen was collected from healthy donors （n = 15）. Semen parameters and quality were assessed in accordance with the World Health Organization （WHO） criteria. Swim-up sperm were fixed and subjected to immunocytochemistry and immunoelectronmicroscopy with specific antibodies directed against PAR-2 and EGF-R. Protein extractions from swim-up spermatozoa were analyzed by Western blotting with antibodies for both receptors. Motility of spermatozoa was evaluated by computer-assisted semen analysis. Results： Immunocytochemistry found PAR-2 and EGF-R in approximately 30% of examined human ejaculated spermatozoa. Both receptors were localized in the plasma membrane. Like tryptase, the PAR-2 synthetic agonist SLIGKV reduced sperm motility, and this effect was inhibited by application of two specific EGF-R pathway blockers （AG1478 and PD168393）. Conclusion： The observed reduction of sperm motility by tryptase through the PAR-2 receptor involves EGF-R pathways.展开更多
AIM:To determine the molecular mechanisms of Shugan decoction(SGD) in the regulation of colonic motility and visceral hyperalgesia(VHL) in irritable bowel syndrome(IBS).METHODS:The chemical compounds contained in SGD ...AIM:To determine the molecular mechanisms of Shugan decoction(SGD) in the regulation of colonic motility and visceral hyperalgesia(VHL) in irritable bowel syndrome(IBS).METHODS:The chemical compounds contained in SGD were measured by high-performance liquid chromatography.A rat model of IBS was induced by chronic water avoidance stress(WAS).The number of fecal pellets was counted after WAS and the pain pressure threshold was measured by colorectal distension.Morphological changes in colonic mucosa were detected by hematoxylin-eosin staining.The contents of tumor necrosis factor(TNF)-αin colonic tissue and calcitonin-gene-related peptide(CGRP)in serum were measured by ELISA.The protein expression of serotonin[5-hydroxytryptamide(5-HT)],serotonin transporter(SERT),chromogranin A(Cg A)and CGRP incolon tissue was measured by immunohistochemistry.RESULTS:SGD inhibited colonic motility dysfunction and VHL in rats with IBS.Blockers of transient receptor potential(TRP)vanilloid 1(TRPV1)(Ruthenium Red)and TRP ankyrin-1(TRPA1)(HC-030031)and activator of protease-activated receptor(PAR)4 increased the pain pressure threshold,whereas activators of PAR2and TRPV4 decreased the pain pressure threshold in rats with IBS.The effect of SGD on pain pressure threshold in these rats was abolished by activators of TRPV1(capsaicin),TRPV4(RN1747),TRPA1(Polygodial)and PAR2(AC55541).In addition,CGRP levels in serum and colonic tissue were both increased in these rats.TNF-αlevel in colonic tissue was also significantly upregulated.However,the levels of 5-HT,SERT and Cg A in colonic tissue were decreased.All these pathological changes in rats with IBS were attenuated by SGD.CONCLUSION:SGD alleviated VHL and attenuated colon motility in IBS,partly by regulating TRPV1,TRPV4,TRPA1,PAR2,5-HT,Cg A and SERT,and reducing CGRP and TNF-αlevel.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
Summary： The role of protease activated receptor-2 （PAR-2） in the renal tubulointerstitial lesion induced by unilateral ureteral obstruction （UUO） was explored. Mice were sacrificed on the day 1, 3, 5, 7, 10, 14 ...Summary： The role of protease activated receptor-2 （PAR-2） in the renal tubulointerstitial lesion induced by unilateral ureteral obstruction （UUO） was explored. Mice were sacrificed on the day 1, 3, 5, 7, 10, 14 and 21 after UUO. The expression of PAR-2 mRNA and protein and a-smooth muscle actin （α-SMA） protein in tubuloin,terstitium was detected by RT-PCR and immunohistochemistry at each time point, respedtively. The results showed that the PAR-2 expression in renal tubulointerstitium was increased progressively starting from 24 h to the day 14 post-ligation, and it was significantly associated with the relative volume of interstitium and the positive area of α-SMA. PAR-2 was mainly expressed in renal tubule epithelial cells, especially in proximal tubular cells. It also located in renal capillary ansa, interstitial infiltrate cells and fibroblasts. It was concluded that PAR-2 was active in interstitial and tubular cells in the early phase of fibrotic process and played an important role in mediating the tubulointerstitial lesion after UUO.展开更多
The gastrointestinal barrier is-with approximately 400 m^2-the human body's largest surface separating the external environment from the internal milieu. This barrier serves a dual function: permitting the absorpt...The gastrointestinal barrier is-with approximately 400 m^2-the human body's largest surface separating the external environment from the internal milieu. This barrier serves a dual function: permitting the absorption of nutrients, water and electrolytes on the one hand, while limiting host contact with noxious luminal antigens on the other hand. To maintain this selective barrier, junction protein complexes seal the intercellular space between adjacent epithelial cells and regulate the paracellular transport. Increased intestinal permeability is associated with and suggested as a player in the pathophysiology of various gastrointestinal and extraintestinal diseases such as inflammatory bowel disease, celiac disease and type 1 diabetes. The gastrointestinal tract is exposed to high levels of endogenous and exogenous proteases, both in the lumen and in the mucosa. There is increasing evidence to suggest that a dysregulation of the protease/antiprotease balance in the gut contributes to epithelial damage and increased permeability. Excessive proteolysis leads to direct cleavage of intercellular junction proteins, or to opening of the junction proteins via activation of protease activated receptors. In addition, proteases regulate the activity and availability of cytokines and growth factors, which are also known modulators of intestinal permeability. This review aims at outlining the mechanisms by which proteases alter the intestinal permeability. More knowledge on the role of proteases in mucosal homeostasis and gastrointestinal barrier function will definitely contribute to the identification of new therapeutic targets for permeability-related diseases.展开更多
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
Activated protein C(APC) is a physiological anticoagulant, derived from its precursor protein C(PC). Independent of its anticoagulation, APC possesses strong anti-inflammatory, anti-apoptotic and barrier protective pr...Activated protein C(APC) is a physiological anticoagulant, derived from its precursor protein C(PC). Independent of its anticoagulation, APC possesses strong anti-inflammatory, anti-apoptotic and barrier protective properties which appear to be protective in a number of disorders including chronic wound healing. The epidermis is the outermost skin layer and provides the first line of defence against the external environment. Keratinocytes are the most predominant cells in the epidermis and play a critical role in maintaining epidermal barrier function. PC/APC and its receptor, endothelial protein C receptor(EPCR), once thought to be restricted to the endothelium, are abundantly expressed by skin epidermal keratinocytes. These cells respond to APC by upregulating proliferation, migration and matrix metalloproteinase-2 activity and inhibiting apoptosis/inflammation leading to a wound healing phenotype. APC also increases barrier function of keratinocyte monolayers by promoting the expression of tight junction proteins and re-distributing them to cell-cell contacts. These cytoprotective properties of APC are mediated through EPCR, protease-activated receptors, epidermal growth factor receptor or Tie2. Future preventive and therapeutic uses of APC in skin disorders associated with disruption of barrier function and inflammation look promising. This review will focus on APC's function in skin epidermis/keratinocytes and its therapeutical potential in skin inflammatory conditions.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
文摘Aim： To investigate mechanisms of tryptase-induced reduction of sperm motility and explore whether epidermal growth factor receptor （EGF-R） and protease activated receptor 2 （PAR-2）- associated pathways are involved. Methods： Fresh semen was collected from healthy donors （n = 15）. Semen parameters and quality were assessed in accordance with the World Health Organization （WHO） criteria. Swim-up sperm were fixed and subjected to immunocytochemistry and immunoelectronmicroscopy with specific antibodies directed against PAR-2 and EGF-R. Protein extractions from swim-up spermatozoa were analyzed by Western blotting with antibodies for both receptors. Motility of spermatozoa was evaluated by computer-assisted semen analysis. Results： Immunocytochemistry found PAR-2 and EGF-R in approximately 30% of examined human ejaculated spermatozoa. Both receptors were localized in the plasma membrane. Like tryptase, the PAR-2 synthetic agonist SLIGKV reduced sperm motility, and this effect was inhibited by application of two specific EGF-R pathway blockers （AG1478 and PD168393）. Conclusion： The observed reduction of sperm motility by tryptase through the PAR-2 receptor involves EGF-R pathways.
基金Supported by Innovation Program of the Shanghai Municipal Education Commission,No.12YZ065National Natural Science Foundation of China,No.81072786,No.81473630 and No.81202665+2 种基金Longhua Medical Project,No.D-09High level Project of the University of Educational Commission of Shanghai,China,No.2008GSP19Shanghai Leading Academic Discipline Project,No.J50305
文摘AIM:To determine the molecular mechanisms of Shugan decoction(SGD) in the regulation of colonic motility and visceral hyperalgesia(VHL) in irritable bowel syndrome(IBS).METHODS:The chemical compounds contained in SGD were measured by high-performance liquid chromatography.A rat model of IBS was induced by chronic water avoidance stress(WAS).The number of fecal pellets was counted after WAS and the pain pressure threshold was measured by colorectal distension.Morphological changes in colonic mucosa were detected by hematoxylin-eosin staining.The contents of tumor necrosis factor(TNF)-αin colonic tissue and calcitonin-gene-related peptide(CGRP)in serum were measured by ELISA.The protein expression of serotonin[5-hydroxytryptamide(5-HT)],serotonin transporter(SERT),chromogranin A(Cg A)and CGRP incolon tissue was measured by immunohistochemistry.RESULTS:SGD inhibited colonic motility dysfunction and VHL in rats with IBS.Blockers of transient receptor potential(TRP)vanilloid 1(TRPV1)(Ruthenium Red)and TRP ankyrin-1(TRPA1)(HC-030031)and activator of protease-activated receptor(PAR)4 increased the pain pressure threshold,whereas activators of PAR2and TRPV4 decreased the pain pressure threshold in rats with IBS.The effect of SGD on pain pressure threshold in these rats was abolished by activators of TRPV1(capsaicin),TRPV4(RN1747),TRPA1(Polygodial)and PAR2(AC55541).In addition,CGRP levels in serum and colonic tissue were both increased in these rats.TNF-αlevel in colonic tissue was also significantly upregulated.However,the levels of 5-HT,SERT and Cg A in colonic tissue were decreased.All these pathological changes in rats with IBS were attenuated by SGD.CONCLUSION:SGD alleviated VHL and attenuated colon motility in IBS,partly by regulating TRPV1,TRPV4,TRPA1,PAR2,5-HT,Cg A and SERT,and reducing CGRP and TNF-αlevel.
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Summary： The role of protease activated receptor-2 （PAR-2） in the renal tubulointerstitial lesion induced by unilateral ureteral obstruction （UUO） was explored. Mice were sacrificed on the day 1, 3, 5, 7, 10, 14 and 21 after UUO. The expression of PAR-2 mRNA and protein and a-smooth muscle actin （α-SMA） protein in tubuloin,terstitium was detected by RT-PCR and immunohistochemistry at each time point, respedtively. The results showed that the PAR-2 expression in renal tubulointerstitium was increased progressively starting from 24 h to the day 14 post-ligation, and it was significantly associated with the relative volume of interstitium and the positive area of α-SMA. PAR-2 was mainly expressed in renal tubule epithelial cells, especially in proximal tubular cells. It also located in renal capillary ansa, interstitial infiltrate cells and fibroblasts. It was concluded that PAR-2 was active in interstitial and tubular cells in the early phase of fibrotic process and played an important role in mediating the tubulointerstitial lesion after UUO.
文摘The gastrointestinal barrier is-with approximately 400 m^2-the human body's largest surface separating the external environment from the internal milieu. This barrier serves a dual function: permitting the absorption of nutrients, water and electrolytes on the one hand, while limiting host contact with noxious luminal antigens on the other hand. To maintain this selective barrier, junction protein complexes seal the intercellular space between adjacent epithelial cells and regulate the paracellular transport. Increased intestinal permeability is associated with and suggested as a player in the pathophysiology of various gastrointestinal and extraintestinal diseases such as inflammatory bowel disease, celiac disease and type 1 diabetes. The gastrointestinal tract is exposed to high levels of endogenous and exogenous proteases, both in the lumen and in the mucosa. There is increasing evidence to suggest that a dysregulation of the protease/antiprotease balance in the gut contributes to epithelial damage and increased permeability. Excessive proteolysis leads to direct cleavage of intercellular junction proteins, or to opening of the junction proteins via activation of protease activated receptors. In addition, proteases regulate the activity and availability of cytokines and growth factors, which are also known modulators of intestinal permeability. This review aims at outlining the mechanisms by which proteases alter the intestinal permeability. More knowledge on the role of proteases in mucosal homeostasis and gastrointestinal barrier function will definitely contribute to the identification of new therapeutic targets for permeability-related diseases.
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 Ulysses Club Arthritis Research Fellowshipand Henry Langley Arthritis Research Fellowship respectively,to McKelvey K and Xue M
文摘Activated protein C(APC) is a physiological anticoagulant, derived from its precursor protein C(PC). Independent of its anticoagulation, APC possesses strong anti-inflammatory, anti-apoptotic and barrier protective properties which appear to be protective in a number of disorders including chronic wound healing. The epidermis is the outermost skin layer and provides the first line of defence against the external environment. Keratinocytes are the most predominant cells in the epidermis and play a critical role in maintaining epidermal barrier function. PC/APC and its receptor, endothelial protein C receptor(EPCR), once thought to be restricted to the endothelium, are abundantly expressed by skin epidermal keratinocytes. These cells respond to APC by upregulating proliferation, migration and matrix metalloproteinase-2 activity and inhibiting apoptosis/inflammation leading to a wound healing phenotype. APC also increases barrier function of keratinocyte monolayers by promoting the expression of tight junction proteins and re-distributing them to cell-cell contacts. These cytoprotective properties of APC are mediated through EPCR, protease-activated receptors, epidermal growth factor receptor or Tie2. Future preventive and therapeutic uses of APC in skin disorders associated with disruption of barrier function and inflammation look promising. This review will focus on APC's function in skin epidermis/keratinocytes and its therapeutical potential in skin inflammatory conditions.
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.
