Benzylisoquinoline alkaloids(BIAs)are a structurally diverse group of plant metabolites renowned for their pharmacological properties.However,sustainable sources for these compounds remain limited.Consequently,researc...Benzylisoquinoline alkaloids(BIAs)are a structurally diverse group of plant metabolites renowned for their pharmacological properties.However,sustainable sources for these compounds remain limited.Consequently,researchers are focusing on elucidating BIA biosynthetic pathways and genes to explore alternative sources using synthetic biology approaches.CYP80B,a family of cytochrome P450(CYP450)enzymes,plays a crucial role in BIA biosynthesis.Previously reported CYP80Bs are known to catalyze the 3′-hydroxylation of(S)-Nmethylcoclaurine,with the N-methyl group essential for catalytic activity.In this study,we successfully cloned a full-length CYP80B gene(St CYP80B)from Stephania tetrandra(S.tetrandra)and identified its function using a yeast heterologous expression system.Both in vivo yeast feeding and in vitro enzyme analysis demonstrated that St CYP80B could catalyze Nmethylcoclaurine and coclaurine into their respective 3'-hydroxylated products.Notably,St CYP80B exhibited an expanded substrate selectivity compared to previously reported wildtype CYP80Bs,as it did not require an N-methyl group for hydroxylase activity.Furthermore,St CYP80B displayed a clear preference for the(S)-configuration.Co-expression of St CYP80B with the CYP450 reductases(CPRs,StCPR1,and StCPR2),also cloned from S.tetrandra,significantly enhanced the catalytic activity towards(S)-coclaurine.Site-directed mutagenesis of St CYP80B revealed that the residue H205 is crucial for coclaurine catalysis.Additionally,St CYP80B exhibited tissue-specific expression in plants.This study provides new genetic resources for the biosynthesis of BIAs and further elucidates their synthetic pathway in natural plant systems.展开更多
CONSPECTUS:Controlling self-assembled peptide nanostructures has emerged as a significant area of research,offering versatile tools for developing functional materials for various applications.This Account emphasizes ...CONSPECTUS:Controlling self-assembled peptide nanostructures has emerged as a significant area of research,offering versatile tools for developing functional materials for various applications.This Account emphasizes the essential role of noncovalent interactions,particularly in peptide-based materials.Key forces,such as aromatic stacking and hydrogen bonding,are crucial for promoting molecular aggregation and stabilizing supramolecular structures.Numerous studies demonstrate how these interactions influence the phase transitions and the morphology of self-assembled structures.Recent advances in computational methodologies,including molecular dynamics simulations and machine learning,have significantly enhanced our understanding of self-assembly processes.These tools enable researchers to predict how molecular properties,such as hydrophobicity,charge distribution,and aromaticity,affect assembly behavior.Simulations uncover the energetic landscapes governing peptide aggregation,providing insights into the kinetic pathways and thermodynamic stabilities.Meanwhile,machine learning facilitates the rapid screening of peptide libraries,identifying sequences with optimal self-assembly characteristics,and accelerating material design with tailored functionalities.Beyond their structural and physicochemical properties,self-assembled peptide nanostructures hold immense potential in biological applications due to their versatility and biocompatibility.By manipulating molecular interactions,researchers have engineered responsive systems that interact with cellular environments to elicit specific biological responses.These peptide nanostructures can mimic extracellular matrices,facilitating cell adhesion,proliferation,and differentiation.They also show promise in modulating immune responses,recruiting immune cells,and regulating signaling pathways,making them valuable tools in immunotherapy and regenerative medicine.Moreover,their ability to disrupt bacterial membranes positions them as innovative alternatives to conventional antibiotics,addressing the urgent need for solutions to antimicrobial resistance.Despite its promise,peptide self-assembly faces several challenges.The assembly process is highly sensitive to environmental conditions,such as pH,temperature,and ionic strength,leading to variability in the morphology and properties.Furthermore,peptide aggregation can result in heterogeneous and poorly defined assemblies,complicating the reproducibility and scalability.Designing peptides with predictable self-assembly behavior remains a significant hurdle.Looking ahead,integrating computational predictions with experimental validations will be crucial in discovering novel peptide sequences with tailored self-assembly properties.Machine learning,combined with high-throughput screening techniques,will enable the rapid identification of optimal peptide sequences.In situ characterization tools,such as cryoelectron microscopy and advanced spectroscopy,will provide deeper insights into assembly mechanisms,aiding the rational design of peptide materials.As research progresses,the dynamic and reversible nature of noncovalent interactions can be leveraged to create adaptive responsive to environmental stimuli.Self-assembled peptide nanostructures are poised for impactful applications in biomedicine including targeted drug delivery,tissue repair,and advanced therapeutic strategies.Ultimately,these nanostructures represent a powerful platform for addressing complex challenges in biomedicine and beyond,paving the way for transformative breakthroughs in science and technology.展开更多
Alcohol abuse leads to alcoholic liver disease and no effective therapy is currently available.Wuzhi Tablet(WZ), a preparation of extract from Schisandra sphenanthera that is a traditional hepatoprotective herb, exert...Alcohol abuse leads to alcoholic liver disease and no effective therapy is currently available.Wuzhi Tablet(WZ), a preparation of extract from Schisandra sphenanthera that is a traditional hepatoprotective herb, exerted a significant protective effect against acetaminophen-induced liver injury in our recent studies, but whether WZ can alleviate alcohol-induced toxicity remains unclear. This study aimed to investigate the contribution of WZ to alcohol-induced liver injury by using chronic-binge and acute models of alcohol feeding. The activities of ALT and AST in serum were assessed as well as the level of GSH and the activity of SOD in the liver. The expression of CYP2E1 and proteins in the NRF2-ARE signaling pathway including NRF2, GCLC, GCLM, HO-1 were measured, and the effect of WZ on NRF2 transcriptional activity was determined. We found that both models resulted in liver steatosis accompanied by increased transaminase activities, but that liver injury was significantly attenuated by WZ. WZ administration also inhibited CYP2E1 expression induced by alcohol, and elevated the level of GSH and the activity of SOD in the liver. Moreover, the NRF2-ARE signaling pathway was activated by WZ andthe target genes were all upregulated. Furthermore, WZ significantly activated NRF2 transcriptional activity. Collectively, our study demonstrates that WZ protected against alcohol-induced liver injury by reducing oxidative stress and improving antioxidant defense, possibly by activating the NRF2-ARE pathway.展开更多
Introduction Internal biliary fistula is a potentially serious complication of laparoscopic cholecystectomy[1].Biliary-colonic fistula is a rare type of internal biliary fistula.Formation of a biliary-colonic fistula ...Introduction Internal biliary fistula is a potentially serious complication of laparoscopic cholecystectomy[1].Biliary-colonic fistula is a rare type of internal biliary fistula.Formation of a biliary-colonic fistula can occur as the result of surgical injury,stone obstruction,and biliary hypertension.More infrequent causes include intestinal ulcer and malignant tumor.The formation of a fistula also has the effect of infection and inflammation.While very few cases of biliary-colonic fistulas have been reported,these cases typically present with the aforementioned clinical presentations[2,3].In the present case,a biliary-colonic fistula resulting from bile-duct injury after laparoscopic cholecystectomy was identified by endoscopic retrograde cholangiopancreatography(ERCP).We innovatively adopted ERCP combined with colonoscopy to clamp the sinus tract for the patient.展开更多
Introduction The accessory hepatic duct is a variation of the biliary tree and is considered to be an important factor contributing to bile duct injury during surgery[1].Accessory hepatic duct stones are a rare form o...Introduction The accessory hepatic duct is a variation of the biliary tree and is considered to be an important factor contributing to bile duct injury during surgery[1].Accessory hepatic duct stones are a rare form of cholelithiasis.The angle at which the accessory hepatic duct opens into the common bile duct makes it difficult to remove stones using conventional endoscopic retrograde cholangiopancreatography(ERCP).We reported a rare and insidious case of an accessory hepatic duct stone.The patient’s abdominal computed tomography(CT)did not reveal any abnormalities,but endoscopic ultrasound revealed a stone in the bile duct opening into a branch of the common bile duct.The patient underwent ERCP,and cholangiography showed no abnormalities.However,the accessory hepatic duct opening was found in the common bile duct and the accessory hepatic duct stones were successfully removed using the EyeMax Choledochoscope System Digital Controller(Nanjing,China).展开更多
文摘Benzylisoquinoline alkaloids(BIAs)are a structurally diverse group of plant metabolites renowned for their pharmacological properties.However,sustainable sources for these compounds remain limited.Consequently,researchers are focusing on elucidating BIA biosynthetic pathways and genes to explore alternative sources using synthetic biology approaches.CYP80B,a family of cytochrome P450(CYP450)enzymes,plays a crucial role in BIA biosynthesis.Previously reported CYP80Bs are known to catalyze the 3′-hydroxylation of(S)-Nmethylcoclaurine,with the N-methyl group essential for catalytic activity.In this study,we successfully cloned a full-length CYP80B gene(St CYP80B)from Stephania tetrandra(S.tetrandra)and identified its function using a yeast heterologous expression system.Both in vivo yeast feeding and in vitro enzyme analysis demonstrated that St CYP80B could catalyze Nmethylcoclaurine and coclaurine into their respective 3'-hydroxylated products.Notably,St CYP80B exhibited an expanded substrate selectivity compared to previously reported wildtype CYP80Bs,as it did not require an N-methyl group for hydroxylase activity.Furthermore,St CYP80B displayed a clear preference for the(S)-configuration.Co-expression of St CYP80B with the CYP450 reductases(CPRs,StCPR1,and StCPR2),also cloned from S.tetrandra,significantly enhanced the catalytic activity towards(S)-coclaurine.Site-directed mutagenesis of St CYP80B revealed that the residue H205 is crucial for coclaurine catalysis.Additionally,St CYP80B exhibited tissue-specific expression in plants.This study provides new genetic resources for the biosynthesis of BIAs and further elucidates their synthetic pathway in natural plant systems.
基金supported by the National Natural Science Foundation of China(82272145)and the Foundation of Westlake University.
文摘CONSPECTUS:Controlling self-assembled peptide nanostructures has emerged as a significant area of research,offering versatile tools for developing functional materials for various applications.This Account emphasizes the essential role of noncovalent interactions,particularly in peptide-based materials.Key forces,such as aromatic stacking and hydrogen bonding,are crucial for promoting molecular aggregation and stabilizing supramolecular structures.Numerous studies demonstrate how these interactions influence the phase transitions and the morphology of self-assembled structures.Recent advances in computational methodologies,including molecular dynamics simulations and machine learning,have significantly enhanced our understanding of self-assembly processes.These tools enable researchers to predict how molecular properties,such as hydrophobicity,charge distribution,and aromaticity,affect assembly behavior.Simulations uncover the energetic landscapes governing peptide aggregation,providing insights into the kinetic pathways and thermodynamic stabilities.Meanwhile,machine learning facilitates the rapid screening of peptide libraries,identifying sequences with optimal self-assembly characteristics,and accelerating material design with tailored functionalities.Beyond their structural and physicochemical properties,self-assembled peptide nanostructures hold immense potential in biological applications due to their versatility and biocompatibility.By manipulating molecular interactions,researchers have engineered responsive systems that interact with cellular environments to elicit specific biological responses.These peptide nanostructures can mimic extracellular matrices,facilitating cell adhesion,proliferation,and differentiation.They also show promise in modulating immune responses,recruiting immune cells,and regulating signaling pathways,making them valuable tools in immunotherapy and regenerative medicine.Moreover,their ability to disrupt bacterial membranes positions them as innovative alternatives to conventional antibiotics,addressing the urgent need for solutions to antimicrobial resistance.Despite its promise,peptide self-assembly faces several challenges.The assembly process is highly sensitive to environmental conditions,such as pH,temperature,and ionic strength,leading to variability in the morphology and properties.Furthermore,peptide aggregation can result in heterogeneous and poorly defined assemblies,complicating the reproducibility and scalability.Designing peptides with predictable self-assembly behavior remains a significant hurdle.Looking ahead,integrating computational predictions with experimental validations will be crucial in discovering novel peptide sequences with tailored self-assembly properties.Machine learning,combined with high-throughput screening techniques,will enable the rapid identification of optimal peptide sequences.In situ characterization tools,such as cryoelectron microscopy and advanced spectroscopy,will provide deeper insights into assembly mechanisms,aiding the rational design of peptide materials.As research progresses,the dynamic and reversible nature of noncovalent interactions can be leveraged to create adaptive responsive to environmental stimuli.Self-assembled peptide nanostructures are poised for impactful applications in biomedicine including targeted drug delivery,tissue repair,and advanced therapeutic strategies.Ultimately,these nanostructures represent a powerful platform for addressing complex challenges in biomedicine and beyond,paving the way for transformative breakthroughs in science and technology.
基金supported by the National Natural Science Foundation of China (Grant Nos. 81373470, 81573489, 81522047 and 81402998)the Natural Science Foundation of Guangdong Province (No. 2015A030313124)
文摘Alcohol abuse leads to alcoholic liver disease and no effective therapy is currently available.Wuzhi Tablet(WZ), a preparation of extract from Schisandra sphenanthera that is a traditional hepatoprotective herb, exerted a significant protective effect against acetaminophen-induced liver injury in our recent studies, but whether WZ can alleviate alcohol-induced toxicity remains unclear. This study aimed to investigate the contribution of WZ to alcohol-induced liver injury by using chronic-binge and acute models of alcohol feeding. The activities of ALT and AST in serum were assessed as well as the level of GSH and the activity of SOD in the liver. The expression of CYP2E1 and proteins in the NRF2-ARE signaling pathway including NRF2, GCLC, GCLM, HO-1 were measured, and the effect of WZ on NRF2 transcriptional activity was determined. We found that both models resulted in liver steatosis accompanied by increased transaminase activities, but that liver injury was significantly attenuated by WZ. WZ administration also inhibited CYP2E1 expression induced by alcohol, and elevated the level of GSH and the activity of SOD in the liver. Moreover, the NRF2-ARE signaling pathway was activated by WZ andthe target genes were all upregulated. Furthermore, WZ significantly activated NRF2 transcriptional activity. Collectively, our study demonstrates that WZ protected against alcohol-induced liver injury by reducing oxidative stress and improving antioxidant defense, possibly by activating the NRF2-ARE pathway.
基金supported by the Hebei Natural Science Foundation Biomedical Joint Fund Project[grant number H2021206439].
文摘Introduction Internal biliary fistula is a potentially serious complication of laparoscopic cholecystectomy[1].Biliary-colonic fistula is a rare type of internal biliary fistula.Formation of a biliary-colonic fistula can occur as the result of surgical injury,stone obstruction,and biliary hypertension.More infrequent causes include intestinal ulcer and malignant tumor.The formation of a fistula also has the effect of infection and inflammation.While very few cases of biliary-colonic fistulas have been reported,these cases typically present with the aforementioned clinical presentations[2,3].In the present case,a biliary-colonic fistula resulting from bile-duct injury after laparoscopic cholecystectomy was identified by endoscopic retrograde cholangiopancreatography(ERCP).We innovatively adopted ERCP combined with colonoscopy to clamp the sinus tract for the patient.
基金supported by the Hebei Natural Science Foundation Biomedical Joint Fund Project[H2021206439].
文摘Introduction The accessory hepatic duct is a variation of the biliary tree and is considered to be an important factor contributing to bile duct injury during surgery[1].Accessory hepatic duct stones are a rare form of cholelithiasis.The angle at which the accessory hepatic duct opens into the common bile duct makes it difficult to remove stones using conventional endoscopic retrograde cholangiopancreatography(ERCP).We reported a rare and insidious case of an accessory hepatic duct stone.The patient’s abdominal computed tomography(CT)did not reveal any abnormalities,but endoscopic ultrasound revealed a stone in the bile duct opening into a branch of the common bile duct.The patient underwent ERCP,and cholangiography showed no abnormalities.However,the accessory hepatic duct opening was found in the common bile duct and the accessory hepatic duct stones were successfully removed using the EyeMax Choledochoscope System Digital Controller(Nanjing,China).
