AIM: To study the mechanism and effect of nuclear factor-κB (NF-κB) activation and inflammatory response on the extended cold-preserved graft injury after orthotopic liver transplantation (OLT). METHODS: OLT was per...AIM: To study the mechanism and effect of nuclear factor-κB (NF-κB) activation and inflammatory response on the extended cold-preserved graft injury after orthotopic liver transplantation (OLT). METHODS: OLT was performed in rats with varying time of cold ischemia grafts (6, 18 and 24 h in University Wisconsin solution at 4 ℃). We determined the time of NF-κB activation and expression of tumor necrosis factor-α (TNF-α), cytokineinducible neutrophil chemoattractant (CINC), and intercellular adhesion molecule-1 (ICAM-1) within 6 h after reperfusion. Serum alarming aminotransferase (ALT), neutrophil sequestration, circulating neutrophil CD11b and L- selectin expression were also evaluated. RESULTS: The accumulation of neutrophils in the graft was significantly increased in the 18 h and 24 h cold-ischemia groups within 0.5 h after reperfusion, compared with the 6 h group. But the strongly activated neutrophils was slightly increased at 2 h after reperfusion and remained at high levels 4 h after reperfusion, which was synchronized with the common situation of recipients after transplantation. Prolonged cold-preservation did not affect neutrophil accumulation and activation. NF-κB activation preceded the expression of TNF-α, CINC, and ICAM-1 in the liver, which was significantly increased with prolonged cold preservation. In prolonged cold preserved grafts, prominently elevated NF-κB activation occurred at 0.5 h and 1 h, compared with that at 2 h after reperfusion, which was consistent with greatly increased intrahepatic TNF-α response. CONCLUSION: NF-κB activation is correlated with the expression of TNF-α, CINC, and ICAM-1 in vivo in OLT rats. Extended cold preservation of grafts might up-regulate TNF-α, CINC, and ICAM-1 expression in the grafts, most probably through elevated NF-κB activation, and might contribute to neutrophil infiltration in the grafts after reperfusion. Elevated NF-κB activity is harmful to inflammatory response in the grafts, and inhibited NF-κB activity might protect against early graft injury after liver transplantation.展开更多
AIM: Polymorphonuclear neutrophil (PMN) plays a major role in liver ischemia/reperfusion injury. Protective effect of ischemic preconditioning (IP) has been confirmed in liver ischemia/reperfusion injury. The purpose ...AIM: Polymorphonuclear neutrophil (PMN) plays a major role in liver ischemia/reperfusion injury. Protective effect of ischemic preconditioning (IP) has been confirmed in liver ischemia/reperfusion injury. The purpose of this study was to investigate the effect of IP on C-X-C chemokine expression and PMNs recruitment eady after liver transplantation.METHODS: Male Sprague-Dawley rats were used as donors and recipients of orthotopic liver transplantation (OLT). The donor liver was stored 24 hours in University of Wisconsin(UW) solution at 4 ℃ pre-implantation, IP was done by damp of the portal vein and hepatic artery of the donor liver for 10 minutes followed by reperfusion for 10 minutes before harvesting. The neutrophilic infiltration in liver was quantified using a myeloperoxidase (MPO) assay. Intragrafl: expression of macrophage inflammatory protein-2 (MIP-2) mRNA was investigated with in situ hybridization, The serum levels of MIP-2 and tumor necrosis factor (TNF)-α were also monitored,RESULTS: After liver transplantation without IP, the hepatic MPO increased significantly compared with sham operated group. In IP group, PMN in liver indicated by MPO was reduced significantly. In situ hybridization showed no MIP-2 mRNA in sham group but dramatic expression in hepatocytes in non-IP group. In IP group, MIP-2 mRNA was significantly down-regulated. Similarly, serum MIP-2 and TNF-α levels were significantly elevated in non-IP group and both were reduced in IP group.CONCLUSION: IP might protect graft liver from preservation-reperfusion injury after OLT through down-regulating C-X-C chemokine expression of hepatocytes, and alleviating PMNs recruitment after reperfusion.展开更多
AIM. To investigate the effect of pyrrolidine dithiocarbamate (PDTC), a novel nuclear factor-κB (NF-κB) inhibitor, on expression of multiple inflammatory mediators and neutrophilic inflammation of cold preserved gra...AIM. To investigate the effect of pyrrolidine dithiocarbamate (PDTC), a novel nuclear factor-κB (NF-κB) inhibitor, on expression of multiple inflammatory mediators and neutrophilic inflammation of cold preserved grafts after rat liver transplantation and its significance.METHODS: Orthotopic liver transplantation (OLT) was performed after 24 h of cold storage using University of Wisconsin solution with varied concentrations of PDTC. We determined the time course of NF-κB activation and expression of multiple inflammatory signals, such as tumor necrosis factor-α (TNF-α), cytokine-inducible neutrophil chemoattractant (CINC), and intercellular adhesion molecule-1(ICAM-1) by ELISA methods. Serum alanine aminotransferase (ALT), intrahepatic myeloperoxidase (MPO)/WBC (a measure of neutrophil accumulation) and Mac-1 expression (a measure of circulating neutrophil activity) were also evaluated.RESULTS: PDTC decreased NF-κB activation induced by prolonged cold preservation in a dose dependent manner (from 20 mmol/L to 60 mmol/L), diminished TNF-α, CINC,ICAM-1 proteins in the grafts, and reduced the expression f increases in plasma TNF-α levels induced by prolonged old preservation. Neutrophilic inflammation of the graft was significantly suppressed after preservation with PDTC (P<0.05). The total neutrophil accumulation in PDTC (40 mmol/L) group (7.04±0.97) was markedly reduced compared to control group (14.07±1.31) (P<0.05). Mac-1 expression was significantly reduced in PDTC (40 retool/L) group (181±11.3%) compared with the control group (281±13.2%) (P<0.05) at 6 h after reperfusion. Furthermore,PDTC inhibited the increased serum ALT levels after liver transplantation.CONCLUSION: PDTC can inhibit B NF-κB activation and expression of the inflammatory mediators, which are associated with improved graft viability via inhibiting intrahepatic neutrophilic inflammation. Our study suggests that a therapeutic strategy directed at inhibition of NF-κB activation in the transplanted liver might be effective in reducing intrahepatic neutrophilic inflammation, and would be beneficial to cold preserved grafts,展开更多
Two new xanthone glycosides, polygalaxanthone IV and V were isolated from the roots of Polygala tenuifolia Willd. Their structures were established as 6-O-[a-L-rhamnopyranosyl- (12)-b-D-glucopyranosyl]-1-hydroxy-3, 7...Two new xanthone glycosides, polygalaxanthone IV and V were isolated from the roots of Polygala tenuifolia Willd. Their structures were established as 6-O-[a-L-rhamnopyranosyl- (12)-b-D-glucopyranosyl]-1-hydroxy-3, 7-dimethoxyxanthone (polygalaxanthone IV), and 6-O- [a-L-rhamnopyranosyl-(12)-b-D-glucopyranosyl]-1, 3-dihydroxy-7-methoxyxanthone (polyga- laxanthone V), respectively, on the basis of chemical and spectral evidence.展开更多
The basal activity of JNK is low in normal growing cells and inactivated JNK targets p53 for ubiquitination. To elucidate if the C-terminal part of JNK is responsible for its binding to p53, the low background tet-off...The basal activity of JNK is low in normal growing cells and inactivated JNK targets p53 for ubiquitination. To elucidate if the C-terminal part of JNK is responsible for its binding to p53, the low background tet-off inducible NIH3T3 cell line was selected by luciferase reporter gene and a double stable C-JNK Aa (203-424) cell line was established. After withdrawing tetracycline, the C-JNK fragment expression was induced and cell growth was dramati- cally inhibited 24 h later. However, the expresion of p53 was found to be increased after the induction of C-JNK fragment, evaluated by transfecting p21waf-luciferase reporter genes. Our further studies showed that C-JNK fragment could form complex with p53 both in vivo and in vitro. Induction of C-JNK fragment in vivo can increase p53 stability by inhibiting p53 ubiquitination.展开更多
A facile and flexible method to prepare raspberry-like nanoparticles that can be used as a superamphipho- bic coating is reported. Anatase TiO2 nanoparticles were chosen as the core because of their irregular morpholo...A facile and flexible method to prepare raspberry-like nanoparticles that can be used as a superamphipho- bic coating is reported. Anatase TiO2 nanoparticles were chosen as the core because of their irregular morphology and photocatalytic performance. Anatase TiO2 nanoparticles were surrounded tightly by tiny functional fluoride-silica nanoparticles via the hydrolysis-condensation reaction of tetraethoxysi- lane and IH, 1H, 2H, 2H-perfluorodecyl triethoxysilane. The obtained Si-F@TiO2 nanoparticles can be sprayed or dipped directly onto various substrates. The coated film exhibited quite good liquid resistance, even when subjected to water jetting and sand abrasion. The photocatalytic effect of the coated anatase TiO2 with respect to formaldehyde was also studied and discussed. This method will provide more opportunities and fast access to practical applications in surface, environmental, and energy engineering.展开更多
Developing low-cost,efficient,and stable non-precious-metal electrocatalysts with controlled crystal structure,morphology and compositions are highly desirable for hydrogen and oxygen evolution reactions.Herein,a seri...Developing low-cost,efficient,and stable non-precious-metal electrocatalysts with controlled crystal structure,morphology and compositions are highly desirable for hydrogen and oxygen evolution reactions.Herein,a series of phosphorus-doped Fe_(7)S_(8)nanowires integrated within carbon(P-Fe_(7)S_(8)@C)are rationally synthesized via a one-step phosphorization of one-dimensional(1D)Fe-based organicinorganic nanowires.The as-obtained P-Fe_(7)S_(8)@C catalysts with modified electronic configurations present typical porous structure,providing plentiful active sites for rapid reaction kinetics.Density functional calculations demonstrate that the doping Fe_(7)S_(8)with P can effectively enhance the electron density of Fe_(7)S_(8)around the Fermi level and weaken the Fe-H bonding,leading to the decrease of adsorption free energy barrier on active sites.As a result,the optimal catalyst of P-Fe_(7)S_(8)-600@C exhibits a relatively low overpotential of 136 mV for hydrogen evolution reaction(HER)to reach the current density of 10 mA/cm^(2),and a significantly low overpotential of 210 mV for oxygen evolution reaction(OER)at 20 mA/cm^(2)in alkaline media.The work presented here may pave the way to design and synthesis of other prominent Fe-based catalysts for water splitting via electronic regulation.展开更多
基金Supported by the Education Foundation of Xuzhou Anesthesia Laboratory,Jiangsu,No.KJS02055
文摘AIM: To study the mechanism and effect of nuclear factor-κB (NF-κB) activation and inflammatory response on the extended cold-preserved graft injury after orthotopic liver transplantation (OLT). METHODS: OLT was performed in rats with varying time of cold ischemia grafts (6, 18 and 24 h in University Wisconsin solution at 4 ℃). We determined the time of NF-κB activation and expression of tumor necrosis factor-α (TNF-α), cytokineinducible neutrophil chemoattractant (CINC), and intercellular adhesion molecule-1 (ICAM-1) within 6 h after reperfusion. Serum alarming aminotransferase (ALT), neutrophil sequestration, circulating neutrophil CD11b and L- selectin expression were also evaluated. RESULTS: The accumulation of neutrophils in the graft was significantly increased in the 18 h and 24 h cold-ischemia groups within 0.5 h after reperfusion, compared with the 6 h group. But the strongly activated neutrophils was slightly increased at 2 h after reperfusion and remained at high levels 4 h after reperfusion, which was synchronized with the common situation of recipients after transplantation. Prolonged cold-preservation did not affect neutrophil accumulation and activation. NF-κB activation preceded the expression of TNF-α, CINC, and ICAM-1 in the liver, which was significantly increased with prolonged cold preservation. In prolonged cold preserved grafts, prominently elevated NF-κB activation occurred at 0.5 h and 1 h, compared with that at 2 h after reperfusion, which was consistent with greatly increased intrahepatic TNF-α response. CONCLUSION: NF-κB activation is correlated with the expression of TNF-α, CINC, and ICAM-1 in vivo in OLT rats. Extended cold preservation of grafts might up-regulate TNF-α, CINC, and ICAM-1 expression in the grafts, most probably through elevated NF-κB activation, and might contribute to neutrophil infiltration in the grafts after reperfusion. Elevated NF-κB activity is harmful to inflammatory response in the grafts, and inhibited NF-κB activity might protect against early graft injury after liver transplantation.
基金the Chinese Medical Administration Bureau of Jiangsu Province,No.SZ9902
文摘AIM: Polymorphonuclear neutrophil (PMN) plays a major role in liver ischemia/reperfusion injury. Protective effect of ischemic preconditioning (IP) has been confirmed in liver ischemia/reperfusion injury. The purpose of this study was to investigate the effect of IP on C-X-C chemokine expression and PMNs recruitment eady after liver transplantation.METHODS: Male Sprague-Dawley rats were used as donors and recipients of orthotopic liver transplantation (OLT). The donor liver was stored 24 hours in University of Wisconsin(UW) solution at 4 ℃ pre-implantation, IP was done by damp of the portal vein and hepatic artery of the donor liver for 10 minutes followed by reperfusion for 10 minutes before harvesting. The neutrophilic infiltration in liver was quantified using a myeloperoxidase (MPO) assay. Intragrafl: expression of macrophage inflammatory protein-2 (MIP-2) mRNA was investigated with in situ hybridization, The serum levels of MIP-2 and tumor necrosis factor (TNF)-α were also monitored,RESULTS: After liver transplantation without IP, the hepatic MPO increased significantly compared with sham operated group. In IP group, PMN in liver indicated by MPO was reduced significantly. In situ hybridization showed no MIP-2 mRNA in sham group but dramatic expression in hepatocytes in non-IP group. In IP group, MIP-2 mRNA was significantly down-regulated. Similarly, serum MIP-2 and TNF-α levels were significantly elevated in non-IP group and both were reduced in IP group.CONCLUSION: IP might protect graft liver from preservation-reperfusion injury after OLT through down-regulating C-X-C chemokine expression of hepatocytes, and alleviating PMNs recruitment after reperfusion.
基金Supported by Education Foundation of Xuzhou Anesthesia Laboratory of Jiangsu Province,No.KJS02055
文摘AIM. To investigate the effect of pyrrolidine dithiocarbamate (PDTC), a novel nuclear factor-κB (NF-κB) inhibitor, on expression of multiple inflammatory mediators and neutrophilic inflammation of cold preserved grafts after rat liver transplantation and its significance.METHODS: Orthotopic liver transplantation (OLT) was performed after 24 h of cold storage using University of Wisconsin solution with varied concentrations of PDTC. We determined the time course of NF-κB activation and expression of multiple inflammatory signals, such as tumor necrosis factor-α (TNF-α), cytokine-inducible neutrophil chemoattractant (CINC), and intercellular adhesion molecule-1(ICAM-1) by ELISA methods. Serum alanine aminotransferase (ALT), intrahepatic myeloperoxidase (MPO)/WBC (a measure of neutrophil accumulation) and Mac-1 expression (a measure of circulating neutrophil activity) were also evaluated.RESULTS: PDTC decreased NF-κB activation induced by prolonged cold preservation in a dose dependent manner (from 20 mmol/L to 60 mmol/L), diminished TNF-α, CINC,ICAM-1 proteins in the grafts, and reduced the expression f increases in plasma TNF-α levels induced by prolonged old preservation. Neutrophilic inflammation of the graft was significantly suppressed after preservation with PDTC (P<0.05). The total neutrophil accumulation in PDTC (40 mmol/L) group (7.04±0.97) was markedly reduced compared to control group (14.07±1.31) (P<0.05). Mac-1 expression was significantly reduced in PDTC (40 retool/L) group (181±11.3%) compared with the control group (281±13.2%) (P<0.05) at 6 h after reperfusion. Furthermore,PDTC inhibited the increased serum ALT levels after liver transplantation.CONCLUSION: PDTC can inhibit B NF-κB activation and expression of the inflammatory mediators, which are associated with improved graft viability via inhibiting intrahepatic neutrophilic inflammation. Our study suggests that a therapeutic strategy directed at inhibition of NF-κB activation in the transplanted liver might be effective in reducing intrahepatic neutrophilic inflammation, and would be beneficial to cold preserved grafts,
文摘Two new xanthone glycosides, polygalaxanthone IV and V were isolated from the roots of Polygala tenuifolia Willd. Their structures were established as 6-O-[a-L-rhamnopyranosyl- (12)-b-D-glucopyranosyl]-1-hydroxy-3, 7-dimethoxyxanthone (polygalaxanthone IV), and 6-O- [a-L-rhamnopyranosyl-(12)-b-D-glucopyranosyl]-1, 3-dihydroxy-7-methoxyxanthone (polyga- laxanthone V), respectively, on the basis of chemical and spectral evidence.
基金supported by National Natural Science Foundation of China(No.30270556)The National Basic Research Program(No.2002CB513004).
文摘The basal activity of JNK is low in normal growing cells and inactivated JNK targets p53 for ubiquitination. To elucidate if the C-terminal part of JNK is responsible for its binding to p53, the low background tet-off inducible NIH3T3 cell line was selected by luciferase reporter gene and a double stable C-JNK Aa (203-424) cell line was established. After withdrawing tetracycline, the C-JNK fragment expression was induced and cell growth was dramati- cally inhibited 24 h later. However, the expresion of p53 was found to be increased after the induction of C-JNK fragment, evaluated by transfecting p21waf-luciferase reporter genes. Our further studies showed that C-JNK fragment could form complex with p53 both in vivo and in vitro. Induction of C-JNK fragment in vivo can increase p53 stability by inhibiting p53 ubiquitination.
文摘A facile and flexible method to prepare raspberry-like nanoparticles that can be used as a superamphipho- bic coating is reported. Anatase TiO2 nanoparticles were chosen as the core because of their irregular morphology and photocatalytic performance. Anatase TiO2 nanoparticles were surrounded tightly by tiny functional fluoride-silica nanoparticles via the hydrolysis-condensation reaction of tetraethoxysi- lane and IH, 1H, 2H, 2H-perfluorodecyl triethoxysilane. The obtained Si-F@TiO2 nanoparticles can be sprayed or dipped directly onto various substrates. The coated film exhibited quite good liquid resistance, even when subjected to water jetting and sand abrasion. The photocatalytic effect of the coated anatase TiO2 with respect to formaldehyde was also studied and discussed. This method will provide more opportunities and fast access to practical applications in surface, environmental, and energy engineering.
基金the National Natural Science Foundation of China(Nos.21601120 and 21805181)the Science and Technology Commission of Shanghai Municipality(Nos.17ZR1410500 and 19ZR1418100)+1 种基金the High Performance Computing Center of Shanghai UniversityShanghai Engineering Research Center of Intelligent Computing System(No.19DZ2252600)for providing the computing resources and technical support。
文摘Developing low-cost,efficient,and stable non-precious-metal electrocatalysts with controlled crystal structure,morphology and compositions are highly desirable for hydrogen and oxygen evolution reactions.Herein,a series of phosphorus-doped Fe_(7)S_(8)nanowires integrated within carbon(P-Fe_(7)S_(8)@C)are rationally synthesized via a one-step phosphorization of one-dimensional(1D)Fe-based organicinorganic nanowires.The as-obtained P-Fe_(7)S_(8)@C catalysts with modified electronic configurations present typical porous structure,providing plentiful active sites for rapid reaction kinetics.Density functional calculations demonstrate that the doping Fe_(7)S_(8)with P can effectively enhance the electron density of Fe_(7)S_(8)around the Fermi level and weaken the Fe-H bonding,leading to the decrease of adsorption free energy barrier on active sites.As a result,the optimal catalyst of P-Fe_(7)S_(8)-600@C exhibits a relatively low overpotential of 136 mV for hydrogen evolution reaction(HER)to reach the current density of 10 mA/cm^(2),and a significantly low overpotential of 210 mV for oxygen evolution reaction(OER)at 20 mA/cm^(2)in alkaline media.The work presented here may pave the way to design and synthesis of other prominent Fe-based catalysts for water splitting via electronic regulation.
