Hepatic ischemia/reperfusion injury(HIRI) is a serious complication that occurs following shock and/or liver surgery. Gut microbiota and their metabolites are key upstream modulators of development of liver injury. He...Hepatic ischemia/reperfusion injury(HIRI) is a serious complication that occurs following shock and/or liver surgery. Gut microbiota and their metabolites are key upstream modulators of development of liver injury. Herein, we investigated the potential contribution of gut microbes to HIRI.Ischemia/reperfusion surgery was performed to establish a murine model of HIRI. 16 S r RNA gene sequencing and metabolomics were used for microbial analysis. Transcriptomics and proteomics analysis were employed to study the host cell responses. Our results establish HIRI was significantly increased when surgery occurred in the evening(ZT12, 20:00) when compared with the morning(ZT0, 08:00);however, antibiotic pretreatment reduced this diurnal variation. The abundance of a microbial metabolite3,4-dihydroxyphenylpropionic acid was significantly higher in ZT0 when compared with ZT12 in the gut and this compound significantly protected mice against HIRI. Furthermore, 3,4-dihydroxyphenylpropionic acid suppressed the macrophage pro-inflammatory response in vivo and in vitro. This metabolite inhibits histone deacetylase activity by reducing its phosphorylation. Histone deacetylase inhibition suppressed macrophage pro-inflammatory activation and diminished the diurnal variation of HIRI. Our findings revealed a novel protective microbial metabolite against HIRI in mice. The potential underlying mechanism was at least in part, via 3,4-dihydroxyphenylpropionic acid-dependent immune regulation and histone deacetylase(HDAC) inhibition in macrophages.展开更多
The construct of artificial nanocatalyts by simulating natural enzymes and thereby bringing new properties for practical applications is still a challenging task to date.In this study,chiral tetrapeptide(L-phenylalani...The construct of artificial nanocatalyts by simulating natural enzymes and thereby bringing new properties for practical applications is still a challenging task to date.In this study,chiral tetrapeptide(L-phenylalanine-L-phenylalanine-L-cysteine-L-histidine)-engineered copper nanoparticles(FFCH@CuNPs)were fabricated as an artificial peroxidase(POD).More interestingly,the nano-catalysts exhibited chiral identification function.In comparison with other nanocatalysts like L-cysteine-,L-histidine-,chiral dipeptide(L-cysteine-L-histidine)-,or chiral tripeptide(L-phenylalanine-L-cysteine-L-histidine)-modified CuNPs,FFCH@CuNPs demonstrated higher POD-mimetic catalytic activity in the 3,3',5,5'-tetramethylbenzidine(TMB)-H_(2)O_(2) system and stronger enantioselectivity in the recognition of 3,4-dihydroxy-D,L-phenylalanine(D,L-DOPA)enantiomers.Considering the strength difference between the intermolecular hydrogen bonding and theπ-πinteractions,the principle behind the chiral discrimination of D,L-DOPA was explored.Furthermore,higher contents of surface Cu2+ions and hydroxyl radicals were found in the FFCH@CuNPs-D-DOPA-TMB-H_(2)O_(2) system than in the FFCH@CuNPs-L-DOPA-TMB-H_(2)O_(2) system.Based on these results,a protocol for distinguishing between D,L-DOPA enantiomers through colorimetric recognition was established.This study provides a new insight into the design and fabrication of oligopeptides@CuNPs-based chiral nanozymes with improved catalytic performance and features additional to those of natural enzymes.展开更多
A new bibenzyl derivative, 3,4-dihydroxy-4,5-dimethoxy bibenzyl, was isolated from a orchid Dendrobium moniliforme. The structure elucidation and 1H,13C NMR assignments were achieved by spectroscopic method.
OBJECTIVE:Electroacupuncture effect on neurological behavior and the expression of tyrosine kinase Janus kinase 2(JAK 2) of ischemic cortex in rats with the focal cerebral ischemia were investigated in this study.METH...OBJECTIVE:Electroacupuncture effect on neurological behavior and the expression of tyrosine kinase Janus kinase 2(JAK 2) of ischemic cortex in rats with the focal cerebral ischemia were investigated in this study.METHODS:The model of focal cerebral ischemia was established by the heat-coagulation induced the occlusion of the middle cerebral artery.The electro-acupuncture was applied on Baihui(GV 20) and Dazhui(GV 14),and AG490 was applied by intracerebroventricular infusion.The expressions of JAK2 mRNA and phospharylatedJAK2(p-JAK2) in the ischemic cortex were observed by in situ hybridization and western blotting.RESULTS:The expressions of JAK2 mRNA and p-JAK2 were rarely found in sham surgery group.In model group,the expression of JAK2 mRNA and JAK2 phosphorylation had increased.After 1 day of cerebral ischemia,the expression had reached its peak.After cerebral ischemia,the expressions of JAK2 mRNA and p-JAK2 were consistent with the neurological deficit score.Electroacupuncture treatment and AG490 intervention were able to improve the neurological deficit score after cerebral ischemia,and down-regulate the expressions of JAK2 mRNAand JAK2 phosphorylation.CONCLUSION:After cerebral ischemia,the excessive expressions of JAK2 and the JAK2 phosphorylation would be one of mechanisms by which the brain injury got worse.The therapy of electro-acupuncture could reduce the expression of JAK2,and inhibit JAK2 phosphorylated activation,so as to block the abnormal activation of signal transduction pathway which was induced by JAK2.展开更多
Nimbya alternantherae is a leaf spot fungus isolated from Alternanthera philoxeroides.It could produce phytotoxin to Alternanthera philoxeroides in several kinds of liquid media,especially in modified Fries.The filtra...Nimbya alternantherae is a leaf spot fungus isolated from Alternanthera philoxeroides.It could produce phytotoxin to Alternanthera philoxeroides in several kinds of liquid media,especially in modified Fries.The filtrate of the pathogen was chromatographed on a DM-130 colophony column eluting with methanol,and evaporation of the solvent gave a brown mush.The crude product was then extracted with ethyl acetate.The toxin could be purified as white needles by re-crystallizing from benzene and acetone（volume ratio is 1∶1） and silica gel chromatograph.The results of elemental analysis,MS,IR and NMR indicate that molecular weight of the toxin was 240,formula was C11H12O6,and its chemical name was 2-acetyl-3,4-dihydroxy-5-methoxyphenyl-acetic acid（Vulculic acid）.展开更多
基金supported by the National Natural Science Foundation of China(81873926,32071124)Natural Science Funds for Distinguished Young Scholar of Guangdong province grant(2016A030306043,China)to Peng Chen+2 种基金Grants from the NSFCGuangdong Joint Foundation of China(U1601225)Natural Science Foundation of China(81971895)Special Support Plan for Outstanding Talents of Guangdong Province(2019JC05Y340,China)to Yong Jiang。
文摘Hepatic ischemia/reperfusion injury(HIRI) is a serious complication that occurs following shock and/or liver surgery. Gut microbiota and their metabolites are key upstream modulators of development of liver injury. Herein, we investigated the potential contribution of gut microbes to HIRI.Ischemia/reperfusion surgery was performed to establish a murine model of HIRI. 16 S r RNA gene sequencing and metabolomics were used for microbial analysis. Transcriptomics and proteomics analysis were employed to study the host cell responses. Our results establish HIRI was significantly increased when surgery occurred in the evening(ZT12, 20:00) when compared with the morning(ZT0, 08:00);however, antibiotic pretreatment reduced this diurnal variation. The abundance of a microbial metabolite3,4-dihydroxyphenylpropionic acid was significantly higher in ZT0 when compared with ZT12 in the gut and this compound significantly protected mice against HIRI. Furthermore, 3,4-dihydroxyphenylpropionic acid suppressed the macrophage pro-inflammatory response in vivo and in vitro. This metabolite inhibits histone deacetylase activity by reducing its phosphorylation. Histone deacetylase inhibition suppressed macrophage pro-inflammatory activation and diminished the diurnal variation of HIRI. Our findings revealed a novel protective microbial metabolite against HIRI in mice. The potential underlying mechanism was at least in part, via 3,4-dihydroxyphenylpropionic acid-dependent immune regulation and histone deacetylase(HDAC) inhibition in macrophages.
基金supported by the National Natural Science Foundation of China(No.22274159)。
文摘The construct of artificial nanocatalyts by simulating natural enzymes and thereby bringing new properties for practical applications is still a challenging task to date.In this study,chiral tetrapeptide(L-phenylalanine-L-phenylalanine-L-cysteine-L-histidine)-engineered copper nanoparticles(FFCH@CuNPs)were fabricated as an artificial peroxidase(POD).More interestingly,the nano-catalysts exhibited chiral identification function.In comparison with other nanocatalysts like L-cysteine-,L-histidine-,chiral dipeptide(L-cysteine-L-histidine)-,or chiral tripeptide(L-phenylalanine-L-cysteine-L-histidine)-modified CuNPs,FFCH@CuNPs demonstrated higher POD-mimetic catalytic activity in the 3,3',5,5'-tetramethylbenzidine(TMB)-H_(2)O_(2) system and stronger enantioselectivity in the recognition of 3,4-dihydroxy-D,L-phenylalanine(D,L-DOPA)enantiomers.Considering the strength difference between the intermolecular hydrogen bonding and theπ-πinteractions,the principle behind the chiral discrimination of D,L-DOPA was explored.Furthermore,higher contents of surface Cu2+ions and hydroxyl radicals were found in the FFCH@CuNPs-D-DOPA-TMB-H_(2)O_(2) system than in the FFCH@CuNPs-L-DOPA-TMB-H_(2)O_(2) system.Based on these results,a protocol for distinguishing between D,L-DOPA enantiomers through colorimetric recognition was established.This study provides a new insight into the design and fabrication of oligopeptides@CuNPs-based chiral nanozymes with improved catalytic performance and features additional to those of natural enzymes.
文摘A new bibenzyl derivative, 3,4-dihydroxy-4,5-dimethoxy bibenzyl, was isolated from a orchid Dendrobium moniliforme. The structure elucidation and 1H,13C NMR assignments were achieved by spectroscopic method.
基金Supported by the Funds of National Basic Research Program of China(973 program,No.2010CB530500)National Natural Science Foundation of China(No.30973788)+1 种基金Guangdong province science and technology projects (No.2010B031500016)Guangdong Natural Science Foundation(No.9351040701000001)
文摘OBJECTIVE:Electroacupuncture effect on neurological behavior and the expression of tyrosine kinase Janus kinase 2(JAK 2) of ischemic cortex in rats with the focal cerebral ischemia were investigated in this study.METHODS:The model of focal cerebral ischemia was established by the heat-coagulation induced the occlusion of the middle cerebral artery.The electro-acupuncture was applied on Baihui(GV 20) and Dazhui(GV 14),and AG490 was applied by intracerebroventricular infusion.The expressions of JAK2 mRNA and phospharylatedJAK2(p-JAK2) in the ischemic cortex were observed by in situ hybridization and western blotting.RESULTS:The expressions of JAK2 mRNA and p-JAK2 were rarely found in sham surgery group.In model group,the expression of JAK2 mRNA and JAK2 phosphorylation had increased.After 1 day of cerebral ischemia,the expression had reached its peak.After cerebral ischemia,the expressions of JAK2 mRNA and p-JAK2 were consistent with the neurological deficit score.Electroacupuncture treatment and AG490 intervention were able to improve the neurological deficit score after cerebral ischemia,and down-regulate the expressions of JAK2 mRNAand JAK2 phosphorylation.CONCLUSION:After cerebral ischemia,the excessive expressions of JAK2 and the JAK2 phosphorylation would be one of mechanisms by which the brain injury got worse.The therapy of electro-acupuncture could reduce the expression of JAK2,and inhibit JAK2 phosphorylated activation,so as to block the abnormal activation of signal transduction pathway which was induced by JAK2.
文摘Nimbya alternantherae is a leaf spot fungus isolated from Alternanthera philoxeroides.It could produce phytotoxin to Alternanthera philoxeroides in several kinds of liquid media,especially in modified Fries.The filtrate of the pathogen was chromatographed on a DM-130 colophony column eluting with methanol,and evaporation of the solvent gave a brown mush.The crude product was then extracted with ethyl acetate.The toxin could be purified as white needles by re-crystallizing from benzene and acetone（volume ratio is 1∶1） and silica gel chromatograph.The results of elemental analysis,MS,IR and NMR indicate that molecular weight of the toxin was 240,formula was C11H12O6,and its chemical name was 2-acetyl-3,4-dihydroxy-5-methoxyphenyl-acetic acid（Vulculic acid）.
