To evaluate the role of tissue factor (TF) and protease activated receptor (PAR)-2 in liver fibrosis. METHODSUsing CCl<sub>4</sub> administration for eight weeks, we induced hepatic fibrosis in wild-type C...To evaluate the role of tissue factor (TF) and protease activated receptor (PAR)-2 in liver fibrosis. METHODSUsing CCl<sub>4</sub> administration for eight weeks, we induced hepatic fibrosis in wild-type C57BL/6 mice and in mice with deletion of the cytoplasmic signalling domain of TF (TF<sup>§CT/§CT</sup>), deletion of PAR-2 (PAR-2<sup>-/-</sup>) and combined deletion of TF signalling domain and PAR-2 (TF<sup>§CT/§CT</sup>/PAR-2<sup>-/-</sup>). Hepatic fibrosis area was assessed by quantitative imaging of picrosirius red staining. Hepatic collagen content was assessed by hydroxyproline levels. Hepatic stellate cells (αSMA positive) and hepatic macrophages (CD68 positive) were identified by immunohistochemistry. Hepatic gene expression was determined by PCR and liver TGFβ1 content by ELISA. RESULTSCCl<sub>4</sub> treated mice with deletion of the PAR-2 gene (PAR-2<sup>-/-</sup>) and the cytoplasmic domain of TF (TF<sup>§CT/§CT</sup>) developed significantly less hepatic fibrosis, characterised by reduced liver fibrosis area and hydroxyproline content, compared to control wildtype mice treated with CCl<sub>4</sub>. The observed reduction in histological fibrosis was accompanied by a significant decrease in the hepatic content of TGFβ, the prototypic fibrogenic cytokine, as well as fewer activated hepatic stellate cells and hepatic macrophages. Deletion of the TF cytoplasmic signalling domain reduced hepatic fibrosis to levels similar to those observed in mice lacking PAR-2 signalling but combined deletion provided no added protection against fibrosis indicating a lack of mutual modulating effects that have been observed in other contexts such as angiogenic responses. CONCLUSIONTissue factor cytoplasmic domain is involved in TF-PAR-2 signalling initiating hepatic fibrosis and is a potential therapeutic target, as its deletion would not impact coagulation.展开更多
Proteases, enzymes catalyzing the hydrolysis of peptide bonds, are present at high concentrations in the gastrointestinal tract. Besides their well-known role in the digestive process, they also function as signaling ...Proteases, enzymes catalyzing the hydrolysis of peptide bonds, are present at high concentrations in the gastrointestinal tract. Besides their well-known role in the digestive process, they also function as signaling molecules through the activation of protease-activated receptors(PARs). Based on their chemical mechanism for catalysis, proteases can be classified into several classes: serine, cysteine, aspartic, metallo- and threonine proteases represent the mammalian protease families. In particular, the class of serine proteases will play a significant role in this review. In the last decades, proteases have been suggested to play a key role in the pathogenesis of visceral hypersensitivity, which is a major factor contributing to abdominal pain in patients with inflammatory bowel diseases and/or irritable bowel syndrome. So far, only a few preclinical animal studies have investigated the effect of protease inhibitors specifically on visceral sensitivity while their effect on inflammation is described in more detail. In our accompanying review we describe their effect on gastrointestinal permeability. On account of their promising results in the field of visceral hypersensitivity, further research is warranted. The aim of this review is to give an overview on the concept of visceral hypersensitivity as well as on the physiological and pathophysiological functions of proteases herein.展开更多
Objective To express mouse peroxisome proliferator activated receptor γ2 (mPPARγ2) in NIH3T3 fibroblasts mediated by the recombinant retrovirus and study its function.Methods The mPPARγ2 gene was subcloned into r...Objective To express mouse peroxisome proliferator activated receptor γ2 (mPPARγ2) in NIH3T3 fibroblasts mediated by the recombinant retrovirus and study its function.Methods The mPPARγ2 gene was subcloned into retrovirus vector pGCEN to generate the recombinant pGCEN/mPPARγ2. Then it was packaged into PA317 cells and selected with G418. Viral supernatants were harvested and then used to infect NIH3T3 fibroblasts. PPARγ activator 5,8,11,14-eicosatetraynoic acid (ETYA) was used to induce the mPPARγ2-expressing NIH3T3 cells into adipocyte differentiation.Results The recombinant retrovirus pGCEN/mPPARγ2 was constructed, and the higher titers of the viral supernatants were obtained. mPPARγ2 was expressed in NIH3T3 cells mediated by the recombinant retrovirus. Lipid accumulation obviously existed in these induced adipocytes which morphologically resembled mature adipocytes in vivo and expressed tissue specific adipocyte P2 (AP2) and Leptin genes.Conclusions An adipocyte differentiation model in vitro was successfully established. The work is the basis for further research on the molecular mechanism of adipocyte differentiation induced by PPARγ2.展开更多
Objective: To observe the protective effect of acupuncture plus mild hypothermia on brain tissues in rats with cerebral ischemia-reperfusion injury (CIRI), and the influence on protein expression levels of phosphor...Objective: To observe the protective effect of acupuncture plus mild hypothermia on brain tissues in rats with cerebral ischemia-reperfusion injury (CIRI), and the influence on protein expression levels of phosphorylated Raf-1, MEK-2 and ERK3/2 in the mitogen-activated protein kinase (MAPK)/extracellular regulated protein kinases (ERK) pathway, and to explore the mechanism of acupuncture plus mild hypothermia therapy for the ischemic stroke. Methods: Ninety Sprague-Dawley (SD) rats were randomly divided into a blank control group, a sham operation group, a model group, an acupuncture group, a mild hypothermia group and an acupuncture plus mild hypothermia group, 15 rats in each group. Except the rats in the blank control group, the remaining rats were used to prepare the middle cerebral artery occlusion (MCAO) models according to the modified occlusion method using lines, while only the occlusion lines were inserted without blocking the brain arteries of rats in the sham operation group. When the vital signs of rats were stable, rats in the blank control group did not receive any intervention; rats in the sham operation group and the model group received fastening without treatment; rats in the acupuncture group, the mild hypothermia group, and the acupuncture plus mild hypothermia group were treated with the corresponding therapeutic methods. 72 h later, observed neurologic injury score, evaluated infarction area ratio by 2,3,5-tripheyl tetrazolium chloride (TTC) staining, determined apoptosis by TUNEL assay, and measured the phosphorylated Raf-1, MEK-2 and ERK3/2 protein expression levels in rat ischemic hippocampal tissues by Western blot assay. Results: Compared with the blank control group and the sham operation group, after modeling, the neurologic injury score, infarction area ratio and apoptotic cells were increased, and phosphorylated Raf-1, MEK-2 and ERK:1/2 protein expression levels were significantly increased in the model group; the differences were statistically significant (P〈0.05 or P〈0.01). Compared with the model group, after acupuncture or mild hypothermia therapy, neurologic injury score and infarction area ratio were decreased; apoptotic cells and phosphowlated Raf-1, MEK-2 and ERK1/2 protein expression levels were significantly decreased; the differences were statistically significant (P〈0.05 or P〈0.01). Compared with the acupuncture group, neurologic injury score and phosphorylated Raf-1, MEK-2 and ERK3/2 protein expression levels were decreased in the acupuncture plus mild hypothermia group; differences between the groups were statistically significant (P〈0.05 or P〈0.01). Compared with the mild hypothermia group, phosphorylated Raf-1, MEK-2 and ERK1/2 protein expression levels decreased in the acupuncture plus mild hypothermia group, and differences were statistically significant (P〈0.01). Conclusion: Acupuncture or mild hypothermia therapy can improve neurologic injury, reduce infarction area and apoptosis, which brought about protective effect on the brain tissues, in the MCAO model. The protective effect of acupuncture plus mild hypothermia group is the strongest. The mechanism may involve the MAPK/ERK pathway, by reducing the phosphorylated Raf-l, MEK-2 and ERK:1/2 protein expression levels.展开更多
文摘To evaluate the role of tissue factor (TF) and protease activated receptor (PAR)-2 in liver fibrosis. METHODSUsing CCl<sub>4</sub> administration for eight weeks, we induced hepatic fibrosis in wild-type C57BL/6 mice and in mice with deletion of the cytoplasmic signalling domain of TF (TF<sup>§CT/§CT</sup>), deletion of PAR-2 (PAR-2<sup>-/-</sup>) and combined deletion of TF signalling domain and PAR-2 (TF<sup>§CT/§CT</sup>/PAR-2<sup>-/-</sup>). Hepatic fibrosis area was assessed by quantitative imaging of picrosirius red staining. Hepatic collagen content was assessed by hydroxyproline levels. Hepatic stellate cells (αSMA positive) and hepatic macrophages (CD68 positive) were identified by immunohistochemistry. Hepatic gene expression was determined by PCR and liver TGFβ1 content by ELISA. RESULTSCCl<sub>4</sub> treated mice with deletion of the PAR-2 gene (PAR-2<sup>-/-</sup>) and the cytoplasmic domain of TF (TF<sup>§CT/§CT</sup>) developed significantly less hepatic fibrosis, characterised by reduced liver fibrosis area and hydroxyproline content, compared to control wildtype mice treated with CCl<sub>4</sub>. The observed reduction in histological fibrosis was accompanied by a significant decrease in the hepatic content of TGFβ, the prototypic fibrogenic cytokine, as well as fewer activated hepatic stellate cells and hepatic macrophages. Deletion of the TF cytoplasmic signalling domain reduced hepatic fibrosis to levels similar to those observed in mice lacking PAR-2 signalling but combined deletion provided no added protection against fibrosis indicating a lack of mutual modulating effects that have been observed in other contexts such as angiogenic responses. CONCLUSIONTissue factor cytoplasmic domain is involved in TF-PAR-2 signalling initiating hepatic fibrosis and is a potential therapeutic target, as its deletion would not impact coagulation.
基金Supported by University Research Fund Doctoral Projects(BOF-DOCPRO),No.DOCPRO4 2014/ID 2964Research Foundation Flanders(FWO),No.G034113N
文摘Proteases, enzymes catalyzing the hydrolysis of peptide bonds, are present at high concentrations in the gastrointestinal tract. Besides their well-known role in the digestive process, they also function as signaling molecules through the activation of protease-activated receptors(PARs). Based on their chemical mechanism for catalysis, proteases can be classified into several classes: serine, cysteine, aspartic, metallo- and threonine proteases represent the mammalian protease families. In particular, the class of serine proteases will play a significant role in this review. In the last decades, proteases have been suggested to play a key role in the pathogenesis of visceral hypersensitivity, which is a major factor contributing to abdominal pain in patients with inflammatory bowel diseases and/or irritable bowel syndrome. So far, only a few preclinical animal studies have investigated the effect of protease inhibitors specifically on visceral sensitivity while their effect on inflammation is described in more detail. In our accompanying review we describe their effect on gastrointestinal permeability. On account of their promising results in the field of visceral hypersensitivity, further research is warranted. The aim of this review is to give an overview on the concept of visceral hypersensitivity as well as on the physiological and pathophysiological functions of proteases herein.
基金ThisstudywassupportedbyagrantfromtheShanghai UnileverResearch&DevelopmentFund (No 980 7)
文摘Objective To express mouse peroxisome proliferator activated receptor γ2 (mPPARγ2) in NIH3T3 fibroblasts mediated by the recombinant retrovirus and study its function.Methods The mPPARγ2 gene was subcloned into retrovirus vector pGCEN to generate the recombinant pGCEN/mPPARγ2. Then it was packaged into PA317 cells and selected with G418. Viral supernatants were harvested and then used to infect NIH3T3 fibroblasts. PPARγ activator 5,8,11,14-eicosatetraynoic acid (ETYA) was used to induce the mPPARγ2-expressing NIH3T3 cells into adipocyte differentiation.Results The recombinant retrovirus pGCEN/mPPARγ2 was constructed, and the higher titers of the viral supernatants were obtained. mPPARγ2 was expressed in NIH3T3 cells mediated by the recombinant retrovirus. Lipid accumulation obviously existed in these induced adipocytes which morphologically resembled mature adipocytes in vivo and expressed tissue specific adipocyte P2 (AP2) and Leptin genes.Conclusions An adipocyte differentiation model in vitro was successfully established. The work is the basis for further research on the molecular mechanism of adipocyte differentiation induced by PPARγ2.
基金supported by National Natural Science Foundation of China(No.81303051)Traditional Chinese Medicine Science Research Planning Project of Hunan Province(No.201471)Province and Ministry Co-construction Key Laboratory for Internal Medicine of Traditional Chinese Medicine of the Education Ministry of China(No.ZYNK201501)~~
文摘Objective: To observe the protective effect of acupuncture plus mild hypothermia on brain tissues in rats with cerebral ischemia-reperfusion injury (CIRI), and the influence on protein expression levels of phosphorylated Raf-1, MEK-2 and ERK3/2 in the mitogen-activated protein kinase (MAPK)/extracellular regulated protein kinases (ERK) pathway, and to explore the mechanism of acupuncture plus mild hypothermia therapy for the ischemic stroke. Methods: Ninety Sprague-Dawley (SD) rats were randomly divided into a blank control group, a sham operation group, a model group, an acupuncture group, a mild hypothermia group and an acupuncture plus mild hypothermia group, 15 rats in each group. Except the rats in the blank control group, the remaining rats were used to prepare the middle cerebral artery occlusion (MCAO) models according to the modified occlusion method using lines, while only the occlusion lines were inserted without blocking the brain arteries of rats in the sham operation group. When the vital signs of rats were stable, rats in the blank control group did not receive any intervention; rats in the sham operation group and the model group received fastening without treatment; rats in the acupuncture group, the mild hypothermia group, and the acupuncture plus mild hypothermia group were treated with the corresponding therapeutic methods. 72 h later, observed neurologic injury score, evaluated infarction area ratio by 2,3,5-tripheyl tetrazolium chloride (TTC) staining, determined apoptosis by TUNEL assay, and measured the phosphorylated Raf-1, MEK-2 and ERK3/2 protein expression levels in rat ischemic hippocampal tissues by Western blot assay. Results: Compared with the blank control group and the sham operation group, after modeling, the neurologic injury score, infarction area ratio and apoptotic cells were increased, and phosphorylated Raf-1, MEK-2 and ERK:1/2 protein expression levels were significantly increased in the model group; the differences were statistically significant (P〈0.05 or P〈0.01). Compared with the model group, after acupuncture or mild hypothermia therapy, neurologic injury score and infarction area ratio were decreased; apoptotic cells and phosphowlated Raf-1, MEK-2 and ERK1/2 protein expression levels were significantly decreased; the differences were statistically significant (P〈0.05 or P〈0.01). Compared with the acupuncture group, neurologic injury score and phosphorylated Raf-1, MEK-2 and ERK3/2 protein expression levels were decreased in the acupuncture plus mild hypothermia group; differences between the groups were statistically significant (P〈0.05 or P〈0.01). Compared with the mild hypothermia group, phosphorylated Raf-1, MEK-2 and ERK1/2 protein expression levels decreased in the acupuncture plus mild hypothermia group, and differences were statistically significant (P〈0.01). Conclusion: Acupuncture or mild hypothermia therapy can improve neurologic injury, reduce infarction area and apoptosis, which brought about protective effect on the brain tissues, in the MCAO model. The protective effect of acupuncture plus mild hypothermia group is the strongest. The mechanism may involve the MAPK/ERK pathway, by reducing the phosphorylated Raf-l, MEK-2 and ERK:1/2 protein expression levels.