BACKGROUND: Traditional Chinese medicine is a potent agent in the management of clinical and experimental acute pancreatitis (AP), but the molecular mechanism of its the- rapeutic action is unclear. Numerous experimen...BACKGROUND: Traditional Chinese medicine is a potent agent in the management of clinical and experimental acute pancreatitis (AP), but the molecular mechanism of its the- rapeutic action is unclear. Numerous experimental and clinical studies have shown that platelet endothelial cell ad- hesion molecule-1 (PECAM-1) is pivotal to leukocyte re- cruitment, which results in microcirculatory injury during inflammation, but its role in acute pancreatitis is poorly un- derstood. We investigated the effects of a compound of tra- ditional Chinese medicine pancreatitis-1 (TCMP-1) on the changes of platelet endothelial cell adhesion molecule-1 (PECAM-1) expression on polymorphonuclear leukocytes (PMNs) in acute edematous pancreatitis (AEP). METHODS: The model of acute pancreatitis was estab- lished by subcutaneous injection of caerulein, and TCMP-1 treated groups were given TCMP-1 by catheterization from mouth to stomach (20 ml/kg) immediately after first time subcutaneous injection of caerulein. The changes of expres- sion of PECAM-1 on leukocytes from the blood of the splenic vein and inferior vena cava were determined by flow cytometry. RESULTS: In the AEP group, expression of PECAM-1 on PMNs was not significantly different between pancreatic microcirculation and systemic circulation at AEP2h and AEP4h time point. Then from AEP4h time point to AEP8h time point, expression of PECAM-1 was up-regulated in systemic circulation while it was down-regulated in pancre- atic microcirculation and was significantly different be- tween pancreatic microcirculation and systemic circulation at AEP8h time point (P<0.05). In the TCMP-1 treated group, compared with the AEP group, expression of PE-CAM-1 on PMNs decreased in different levels between pan- creatic microcirculation and systemic circulation and was of significant difference at AEP8h time point (P <0.05). CONCLUSION: Inhibition of PECAM-1 expression on PMNs may prevent PMNs from transmigration through the endo- thelium and may be one of the treatment mechanisms of TCMP-1 decoction on AEP.展开更多
BACKGROUND:Platelet endothelial cell adhesion molecule-1(PECAM-1),also known as CD31,is mainly distributed in vascular endothelial cells.Studies have shown that PECAM-1 is a very significant indicator of angiogenesis,...BACKGROUND:Platelet endothelial cell adhesion molecule-1(PECAM-1),also known as CD31,is mainly distributed in vascular endothelial cells.Studies have shown that PECAM-1 is a very significant indicator of angiogenesis,and has been used as an indicator for vascular endothelial cells.The present study aimed to explore the relationship between the expression of PECAM-1 and the degree of acute lung injury(ALI) and fibrosis in paraquat(PQ) induced lung injury in rabbits.METHODS:Thirty-six adult New Zealand rabbits were randomly divided into three groups(12rabbits in each group) according to PQ dosage:8 mg/kg(group A),16 mg/kg(group B),and 32 mg/kg(group C).After PQ infusion,the rabbits were monitored for 7 days and then euthanized.The lungs were removed for histological evaluation.Masson staining was used to determine the degree of lung fibrosis(LF),and semi-quantitative immune-histochemistry analysis to determine the expression of PECAM-1.Pearson's product-moment correlation analysis was performed to evaluate the relationship between the expression of PECAM-1 and the extent of lung injuries expressed by ALI score and degree of LF.RESULTS:Rabbits in the three groups showed apparent poisoning.The rabbits survived longer in group A than in groups B and C(6.47±0.99 days vs.6.09±1.04 days vs.4.77±2.04 days)(P<0.05).ALI score was lower in group A than in groups B and C(8.33±1.03 vs.9.83±1.17 vs.11.50±1.38)(P<0.05),and there was statistically significant difference between group B and group C(P=0.03).LF was slighter in group A than in groups B and C(31.09%±2.05%vs.34.37%±1.62%vs.36.54%±0.44%)(P<0.05),and there was statistically significant difference between group B and group C(P=0.026).The PEACAM-1 expression was higher in group A than in groups B and C(20.31%±0.70%vs.19.34%±0.68%vs.18.37%±0.46%)(P<0.05),and there was statistically significant difference between group B and group C(P=0.017).Pearson's correlation analysis showed that the expression of PECAM-1 was negatively correlated to both ALI score(Coe=-0.732,P=0.001)and degree of LF(Coe=-0.779,P<0.001).CONCLUSIONS:The PECAM-1 expression significantly decreases in New Zealand rabbits after PQ poisoning,and the decrease is dose-dependent.The PECAM-1 expression is negatively correlated with ALI score and LF,showing a significant role in the development of lung injuries induced by PQ.展开更多
BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is associated with obesity,insulin resistance and dyslipidaemia and currently is estimated to affect up to a third of all individuals in developed countries.Current s...BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is associated with obesity,insulin resistance and dyslipidaemia and currently is estimated to affect up to a third of all individuals in developed countries.Current standard of care for patients varies according to disease stage,but includes lifestyle interventions common insulin sensitizers,antioxidants and lipid modifiers.However,to date specific therapies have shown little histological or fibrosis stage improvement in large clinical trials,and there is still no licensed therapy for NAFLD.Given the high prevalence,limited treatment options and significant screening costs for the general population,new treatments are urgently required.AIM To assess the potential for inhibition of the amine oxidase enzyme vascular adhesion protein-1(VAP-1)to modify hepatic lipid accumulation in NAFLD.METHODS We have used immunochemical and qPCR analysis to document expression of VAP-1 and key functional proteins and transporters across the NAFLD spectrum.We then utilised hepatocytes in culture and human precision cut liver slices in concert with selective enzyme activity inhibitors to test the effects of activating the semicarbazide-sensitive amine oxidase activity of VAP-1 on hepatic lipid uptake and triglyceride export.A murine model of NAFLD was also used to determine the consequences of VAP-1 knockout and gene expression arrays were used to quantify the effects of VAP-1 activity on key lipid modifying and proinflammatory gene expression.RESULTS We confirmed that increasing severity of NAFLD and progression to cirrhosis was associated with a significant increase in hepatocellular VAP-1 expression.Hepatocytes in vitro exposed to recombinant VAP-1 and its substrate methylamine showed increased lipid accumulation as determined by quantification of Oil Red O uptake.This was recapitulated using hydrogen peroxide,and lipid accumulation was accompanied by changes in expression of the lipid transporter molecules FABP3,FATP6,insulin receptor subunits and PPARα.Human liver tissue exposed to recombinant VAP-1 or substrates for endo/exogenous VAP-1 produced less triglyceride than untreated tissue and demonstrated an increase in steatosis.This response could be inhibited by using bromoethylamine to inhibit the SSAO activity of VAP-1,and mice deficient in VAP-1/AOC3 also demonstrated reduced steatosis on high fat diet.Exposure of human liver tissue to methylamine to activate VAP-1 resulted in increased expression of FABP2 and 4,FATP3-5,caveolin-1,VLDLR,PPARGC1 and genes associated with the inflammatory response.CONCLUSION Our data confirm that the elevations in hepatic VAP-1 expression reported in nonalcoholic steatohepatitis can contribute to steatosis,metabolic disturbance and inflammation.This suggests that targeting the semicarbazide sensitive amine oxidase capacity of VAP-1 may represent a useful adjunct to other therapeutic strategies in NAFLD.展开更多
基金This work was supported by the grants from the National Natural ScienceFoundation of China (No. 39770722 and 39925032).
文摘BACKGROUND: Traditional Chinese medicine is a potent agent in the management of clinical and experimental acute pancreatitis (AP), but the molecular mechanism of its the- rapeutic action is unclear. Numerous experimental and clinical studies have shown that platelet endothelial cell ad- hesion molecule-1 (PECAM-1) is pivotal to leukocyte re- cruitment, which results in microcirculatory injury during inflammation, but its role in acute pancreatitis is poorly un- derstood. We investigated the effects of a compound of tra- ditional Chinese medicine pancreatitis-1 (TCMP-1) on the changes of platelet endothelial cell adhesion molecule-1 (PECAM-1) expression on polymorphonuclear leukocytes (PMNs) in acute edematous pancreatitis (AEP). METHODS: The model of acute pancreatitis was estab- lished by subcutaneous injection of caerulein, and TCMP-1 treated groups were given TCMP-1 by catheterization from mouth to stomach (20 ml/kg) immediately after first time subcutaneous injection of caerulein. The changes of expres- sion of PECAM-1 on leukocytes from the blood of the splenic vein and inferior vena cava were determined by flow cytometry. RESULTS: In the AEP group, expression of PECAM-1 on PMNs was not significantly different between pancreatic microcirculation and systemic circulation at AEP2h and AEP4h time point. Then from AEP4h time point to AEP8h time point, expression of PECAM-1 was up-regulated in systemic circulation while it was down-regulated in pancre- atic microcirculation and was significantly different be- tween pancreatic microcirculation and systemic circulation at AEP8h time point (P<0.05). In the TCMP-1 treated group, compared with the AEP group, expression of PE-CAM-1 on PMNs decreased in different levels between pan- creatic microcirculation and systemic circulation and was of significant difference at AEP8h time point (P <0.05). CONCLUSION: Inhibition of PECAM-1 expression on PMNs may prevent PMNs from transmigration through the endo- thelium and may be one of the treatment mechanisms of TCMP-1 decoction on AEP.
基金supported by grants from Guangdong Medical Research Fund(2010501)Guangzhou Pharmaceutical Health Science Fund(2009-YB-111)
文摘BACKGROUND:Platelet endothelial cell adhesion molecule-1(PECAM-1),also known as CD31,is mainly distributed in vascular endothelial cells.Studies have shown that PECAM-1 is a very significant indicator of angiogenesis,and has been used as an indicator for vascular endothelial cells.The present study aimed to explore the relationship between the expression of PECAM-1 and the degree of acute lung injury(ALI) and fibrosis in paraquat(PQ) induced lung injury in rabbits.METHODS:Thirty-six adult New Zealand rabbits were randomly divided into three groups(12rabbits in each group) according to PQ dosage:8 mg/kg(group A),16 mg/kg(group B),and 32 mg/kg(group C).After PQ infusion,the rabbits were monitored for 7 days and then euthanized.The lungs were removed for histological evaluation.Masson staining was used to determine the degree of lung fibrosis(LF),and semi-quantitative immune-histochemistry analysis to determine the expression of PECAM-1.Pearson's product-moment correlation analysis was performed to evaluate the relationship between the expression of PECAM-1 and the extent of lung injuries expressed by ALI score and degree of LF.RESULTS:Rabbits in the three groups showed apparent poisoning.The rabbits survived longer in group A than in groups B and C(6.47±0.99 days vs.6.09±1.04 days vs.4.77±2.04 days)(P<0.05).ALI score was lower in group A than in groups B and C(8.33±1.03 vs.9.83±1.17 vs.11.50±1.38)(P<0.05),and there was statistically significant difference between group B and group C(P=0.03).LF was slighter in group A than in groups B and C(31.09%±2.05%vs.34.37%±1.62%vs.36.54%±0.44%)(P<0.05),and there was statistically significant difference between group B and group C(P=0.026).The PEACAM-1 expression was higher in group A than in groups B and C(20.31%±0.70%vs.19.34%±0.68%vs.18.37%±0.46%)(P<0.05),and there was statistically significant difference between group B and group C(P=0.017).Pearson's correlation analysis showed that the expression of PECAM-1 was negatively correlated to both ALI score(Coe=-0.732,P=0.001)and degree of LF(Coe=-0.779,P<0.001).CONCLUSIONS:The PECAM-1 expression significantly decreases in New Zealand rabbits after PQ poisoning,and the decrease is dose-dependent.The PECAM-1 expression is negatively correlated with ALI score and LF,showing a significant role in the development of lung injuries induced by PQ.
文摘BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is associated with obesity,insulin resistance and dyslipidaemia and currently is estimated to affect up to a third of all individuals in developed countries.Current standard of care for patients varies according to disease stage,but includes lifestyle interventions common insulin sensitizers,antioxidants and lipid modifiers.However,to date specific therapies have shown little histological or fibrosis stage improvement in large clinical trials,and there is still no licensed therapy for NAFLD.Given the high prevalence,limited treatment options and significant screening costs for the general population,new treatments are urgently required.AIM To assess the potential for inhibition of the amine oxidase enzyme vascular adhesion protein-1(VAP-1)to modify hepatic lipid accumulation in NAFLD.METHODS We have used immunochemical and qPCR analysis to document expression of VAP-1 and key functional proteins and transporters across the NAFLD spectrum.We then utilised hepatocytes in culture and human precision cut liver slices in concert with selective enzyme activity inhibitors to test the effects of activating the semicarbazide-sensitive amine oxidase activity of VAP-1 on hepatic lipid uptake and triglyceride export.A murine model of NAFLD was also used to determine the consequences of VAP-1 knockout and gene expression arrays were used to quantify the effects of VAP-1 activity on key lipid modifying and proinflammatory gene expression.RESULTS We confirmed that increasing severity of NAFLD and progression to cirrhosis was associated with a significant increase in hepatocellular VAP-1 expression.Hepatocytes in vitro exposed to recombinant VAP-1 and its substrate methylamine showed increased lipid accumulation as determined by quantification of Oil Red O uptake.This was recapitulated using hydrogen peroxide,and lipid accumulation was accompanied by changes in expression of the lipid transporter molecules FABP3,FATP6,insulin receptor subunits and PPARα.Human liver tissue exposed to recombinant VAP-1 or substrates for endo/exogenous VAP-1 produced less triglyceride than untreated tissue and demonstrated an increase in steatosis.This response could be inhibited by using bromoethylamine to inhibit the SSAO activity of VAP-1,and mice deficient in VAP-1/AOC3 also demonstrated reduced steatosis on high fat diet.Exposure of human liver tissue to methylamine to activate VAP-1 resulted in increased expression of FABP2 and 4,FATP3-5,caveolin-1,VLDLR,PPARGC1 and genes associated with the inflammatory response.CONCLUSION Our data confirm that the elevations in hepatic VAP-1 expression reported in nonalcoholic steatohepatitis can contribute to steatosis,metabolic disturbance and inflammation.This suggests that targeting the semicarbazide sensitive amine oxidase capacity of VAP-1 may represent a useful adjunct to other therapeutic strategies in NAFLD.
