A series of non-enzymatic graphene functionalized biosensors was developed via deposition precipitation method for lactic acid(LA) detection,which we re characterized by transmission electron micro scopy(TEM),Raman sp...A series of non-enzymatic graphene functionalized biosensors was developed via deposition precipitation method for lactic acid(LA) detection,which we re characterized by transmission electron micro scopy(TEM),Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),gas chromatography-mass spectrometry,liquid chromatography-mass spectro metry,and proton nuclear magnetic re sonance(~1H NMR).The electrochemical performances of the non-enzymatic biosensors were measured by means of the electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV) method.The comprehensive analysis of structures shows that Pt,CeO_(2),and GO components interact with each other.During the storing and releasing oxygen,the valence ratio of Ce^(3+)/Ce^(4+) and the number of oxygen vacancies in CeO_(2) change accordingly,which can be conducive to increasing electronic transmission capacity and finally leads to the improvement of electrocatalytic performance.Among them,the Pt/CeO_(2)/GO biosensor containing 0.47 at% platinum exhibits an excellent electrochemical detection performance with high sensitivity of 12.3 μA·L/(mmol·cm^(2)) and a low limit of detection(LOD) of 5.12 μmol/L in a wide linear range from 10 to 900 μmol/L.In addition,the proposed biosensor possesses a promising anti-interference capability,as well as high stability and good reproducibility,which was assessed by testing the cyclic voltammogram in 0.1 mol/L lactic acid one year later.The underlying mechanism was proposed for electrochemical oxidation of LA to carbon dioxide and acetic acid with the synergistic effect among Pt,CeO_(2),and GO.Furthermore,the results of the standard addition method in real samples(human serum and urine samples) reveal that the lactic acid detection of the non-enzymatic Pt/CeO_(2)/GO biosensor is accompanied by high reliability.Thus,it will be a valuable biosensor for in vitro detection of lactic acid level in clinical samples.展开更多
Porcine reproductive and respiratory syndrome virus(PRRSV)is a major economically devastating pathogen that has evolved various strategies to evade innate immunity.Downregulation of antiviral interferon largely promot...Porcine reproductive and respiratory syndrome virus(PRRSV)is a major economically devastating pathogen that has evolved various strategies to evade innate immunity.Downregulation of antiviral interferon largely promotes PRRSV immunoevasion by utilizing cytoplasmic melanoma differentiation-associated gene 5(MDA5),a receptor that senses viral RNA.In this study,the downregulated transcription and expression levels of porcine MDA5 in PRRSV infection were observed,and the detailed mechanisms were explored.We found that the interaction between P62 and MDA5 is enhanced due to two factors:the phosphorylation modification of the autophagic receptor P62 by the upregulated kinase CK2αand the K63 ubiquitination of porcine MDA5 catalyzed by the E3 ubiquitinase TRIM21 in PRRSV-infected cells.As a result of these modifications,the classic P62-mediated autophagy is triggered.Additionally,porcine MDA5 interacts with the chaperonin containing TCP1 subunit 2(CCT2),which is enhanced by PRRSV nsp3.This interaction promotes the aggregate formation and autophagic clearance of MDA5-CCT2-nsp3 independently of ubiquitination.In summary,enhanced MDA5 degradation occurs in PRRSV infection via two autophagic pathways:the binding of MDA5 with the autophagy receptor P62 and the aggrephagy receptor CCT2,leading to intense innate immune suppression.The research reveals a novel mechanism of immune evasion in PRRSV infection and provides fundamental insights for the development of new vaccines or therapeutic strategies.展开更多
Cerium oxide-based nanozymes have recently drawn much attention in the field of biomedical and antioxidant applications,because of their unique regenerative or autocatalytic properties.Herein,we studied the biomimetic...Cerium oxide-based nanozymes have recently drawn much attention in the field of biomedical and antioxidant applications,because of their unique regenerative or autocatalytic properties.Herein,we studied the biomimetic superoxide dismutase(SOD)nanozymes CeO_(2)-Gd that combines the fluorescence properties of rare earth Gd with the antioxidant properties of CeO_(2)nanoparticles,which was prepared via facile route.The structure and composition of the CeO_(2)-Gd were measured and verified by X-ray powder diffraction(XRD),Raman spectroscopy,transmission electron microscopy(TEM),energydispersive X-ray spectroscopy(EDX),and X-ray electron spectroscopy(XPS).Confocal microscopy was used to image cells.Antioxidant performance and cell viability of these nanozymes were measured in vitro using BGC-803 cell.CeO_(2)-Gd nanozymes with a higher Ce^(3+)/Ce^(4+)ratio show higher superoxide dismutase(SOD)mimetic activity.Their antioxidant activity and fluorescence properties of CeO_(2)-Gd in BGC-803 cancer cells are enhanced by oxygen vacancies generated by doping rare-earth elements Gd.This work may guide the future design of CeO_(2)-Gd-based biomimetic nanozymes for anticancer and antioxidant applications.展开更多
基金supported by the National Natural Science Foundation of China (21971129,22067015)"Grassland Talent"Innovation Team of lnner Mongolia(12000-12102301)+3 种基金Cooperation Project of State Key Laboratory of Baiyun Obo Rare Earth Resource Researches and Comprehensive Utilization (2017Z1950)Science and Technology Innovation Committee of Shenzhen (JCYJ20190822090801701)Scientific Research Projects of Higher Education of Inner Mongolia Autonomous Region(NJZY21285)Research and Practice Project of Postgraduate Education and Teaching Reform in Inner Mongolia Autonomous Region (YJG20191012606)。
文摘A series of non-enzymatic graphene functionalized biosensors was developed via deposition precipitation method for lactic acid(LA) detection,which we re characterized by transmission electron micro scopy(TEM),Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),gas chromatography-mass spectrometry,liquid chromatography-mass spectro metry,and proton nuclear magnetic re sonance(~1H NMR).The electrochemical performances of the non-enzymatic biosensors were measured by means of the electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV) method.The comprehensive analysis of structures shows that Pt,CeO_(2),and GO components interact with each other.During the storing and releasing oxygen,the valence ratio of Ce^(3+)/Ce^(4+) and the number of oxygen vacancies in CeO_(2) change accordingly,which can be conducive to increasing electronic transmission capacity and finally leads to the improvement of electrocatalytic performance.Among them,the Pt/CeO_(2)/GO biosensor containing 0.47 at% platinum exhibits an excellent electrochemical detection performance with high sensitivity of 12.3 μA·L/(mmol·cm^(2)) and a low limit of detection(LOD) of 5.12 μmol/L in a wide linear range from 10 to 900 μmol/L.In addition,the proposed biosensor possesses a promising anti-interference capability,as well as high stability and good reproducibility,which was assessed by testing the cyclic voltammogram in 0.1 mol/L lactic acid one year later.The underlying mechanism was proposed for electrochemical oxidation of LA to carbon dioxide and acetic acid with the synergistic effect among Pt,CeO_(2),and GO.Furthermore,the results of the standard addition method in real samples(human serum and urine samples) reveal that the lactic acid detection of the non-enzymatic Pt/CeO_(2)/GO biosensor is accompanied by high reliability.Thus,it will be a valuable biosensor for in vitro detection of lactic acid level in clinical samples.
基金supported by the Tianjin Synthetic Biotechnology Innovation Capability Improvement Project in China(TSBICIP-KJGG-014)the key underprop project of Tianjin Science and Technology Bureau in China(20YFZCSN00340)to Jinhai Huang。
文摘Porcine reproductive and respiratory syndrome virus(PRRSV)is a major economically devastating pathogen that has evolved various strategies to evade innate immunity.Downregulation of antiviral interferon largely promotes PRRSV immunoevasion by utilizing cytoplasmic melanoma differentiation-associated gene 5(MDA5),a receptor that senses viral RNA.In this study,the downregulated transcription and expression levels of porcine MDA5 in PRRSV infection were observed,and the detailed mechanisms were explored.We found that the interaction between P62 and MDA5 is enhanced due to two factors:the phosphorylation modification of the autophagic receptor P62 by the upregulated kinase CK2αand the K63 ubiquitination of porcine MDA5 catalyzed by the E3 ubiquitinase TRIM21 in PRRSV-infected cells.As a result of these modifications,the classic P62-mediated autophagy is triggered.Additionally,porcine MDA5 interacts with the chaperonin containing TCP1 subunit 2(CCT2),which is enhanced by PRRSV nsp3.This interaction promotes the aggregate formation and autophagic clearance of MDA5-CCT2-nsp3 independently of ubiquitination.In summary,enhanced MDA5 degradation occurs in PRRSV infection via two autophagic pathways:the binding of MDA5 with the autophagy receptor P62 and the aggrephagy receptor CCT2,leading to intense innate immune suppression.The research reveals a novel mechanism of immune evasion in PRRSV infection and provides fundamental insights for the development of new vaccines or therapeutic strategies.
基金Project supported by the National Natural Science Foundation of China(22067015)the Inner Mongolia Education Department Key Project(NJZZ16015)+2 种基金Inner Mongolia Autonomous Region Graduate Education Teaching Reform and Practice Project(YJG20191012606)Science and Technology Innovation Committee of Shenzhen(JCYJ20190822090801701)China Scholarship Council(CSC)。
文摘Cerium oxide-based nanozymes have recently drawn much attention in the field of biomedical and antioxidant applications,because of their unique regenerative or autocatalytic properties.Herein,we studied the biomimetic superoxide dismutase(SOD)nanozymes CeO_(2)-Gd that combines the fluorescence properties of rare earth Gd with the antioxidant properties of CeO_(2)nanoparticles,which was prepared via facile route.The structure and composition of the CeO_(2)-Gd were measured and verified by X-ray powder diffraction(XRD),Raman spectroscopy,transmission electron microscopy(TEM),energydispersive X-ray spectroscopy(EDX),and X-ray electron spectroscopy(XPS).Confocal microscopy was used to image cells.Antioxidant performance and cell viability of these nanozymes were measured in vitro using BGC-803 cell.CeO_(2)-Gd nanozymes with a higher Ce^(3+)/Ce^(4+)ratio show higher superoxide dismutase(SOD)mimetic activity.Their antioxidant activity and fluorescence properties of CeO_(2)-Gd in BGC-803 cancer cells are enhanced by oxygen vacancies generated by doping rare-earth elements Gd.This work may guide the future design of CeO_(2)-Gd-based biomimetic nanozymes for anticancer and antioxidant applications.