Objective To evaluate senile plaque formation and compare the sensitivity of three differentβ-amyloid(Aβ)labeling methods(antibody staining,Gallyas silver staining,and thioflavin-S staining)to detect Aβdeposition.M...Objective To evaluate senile plaque formation and compare the sensitivity of three differentβ-amyloid(Aβ)labeling methods(antibody staining,Gallyas silver staining,and thioflavin-S staining)to detect Aβdeposition.Methods APPswe/PSEN1dE9 transgenic mice(APP/PS1)of different ages were used to examine spatiotemporal changes in Aβplaque deposition.Antibody staining,Gallyas silver staining,and thioflavin-S staining were used to detect Aβplaque deposition in the same brain region of adjacent slices from model mice,and the results were compared.Results With aging,Aβplaques first appeared in the cortex and then the deposition increased throughout the whole brain.Significantly greater plaque deposition was detected by 6E10 antibody than that analyzed with Gallyas silver staining or thioflavin-S staining(P<0.05).Plaque deposition did not show significant difference between the APP/PS1 mice brains assayed with Gallyas silver staining and ones with thioflavin-S staining(P=0.0033).Conclusions The APP/PS1 mouse model of Alzheimer’s disease could mimick the progress of Aβplaques occurred in patients with Alzheimer’s disease.Antibody detection of Aβdeposition may be more sensitive than chemical staining methods.展开更多
G-quadruplex ligands have been accepted as potential therapeutic agents for anticancer treatment. Thioflavin T （ThT）, a highly selective G-quadruplex ligand, can bind G-quadruplex with a fluorescent light-up signal ...G-quadruplex ligands have been accepted as potential therapeutic agents for anticancer treatment. Thioflavin T （ThT）, a highly selective G-quadruplex ligand, can bind G-quadruplex with a fluorescent light-up signal change and high specificity against DNA duplex. However, there are still different opinions that ThT induces/stabilizes G-quadruplex foldings/topologies in human telomere sequence. Here, a sensitive single-molecule nanopore technology was utilized to analyze the interactions between human telomeric DNA （Tel DNA） and ThT. Both translocation time and current blockade were measured to investigate the translocation behaviors. Furthermore, the effects of metal ion （K~ and Na~） and pH on the translocation behaviors were studied. Based on the single-molecule level analysis, there are some conclusions： （1） In the electrolyte solution containing 50 mmol/L I（Cl and 450 mmol/L NaCl, ThT can bind strongly with Tel DNA but nearly does not change the G-quadruplex form; （2） in the presence of high concentration K~, the ThT binding induces the structural change of hybrid G-quadruplex into antiparallel topology with an enhanced structural stability; （3） In either alkaline or acidic buffer, G-quadruplex form will change in certain degree. All above conclusions are helpful to deeply understand the interaction behaviors between Tel DNA and ThT. This nanopore platform, investigating G-quadruplex ligands at the single-molecule level, has great potential for the design of new drugs and sensors.展开更多
The molecular conformations of four silk fibroin crystalline analogues [GAGAG-X] 16(G,Gly;A,Ala;X=Ala,Ser,Tyr or Val,designated eGA,eGS,eGY or eGV),carried out using molecular design and expressed by Escherichia coil(...The molecular conformations of four silk fibroin crystalline analogues [GAGAG-X] 16(G,Gly;A,Ala;X=Ala,Ser,Tyr or Val,designated eGA,eGS,eGY or eGV),carried out using molecular design and expressed by Escherichia coil(E.coli),were evaluated by Raman spectra analysis.The abilities of forming β-sheet structure were determined by thioflavin T(ThT) fluorescence spectra analysis.In terms of molecular conformation,except eGY that could not form significant typical molecular conformation,eGS and eGV were mainly composed of β-sheets while eGA tended to form β-turn.β-turn was also present in eGY and absent in eGS and eGV.In terms of β-sheet structure,eGS had the highest β-sheet content,followed by eGV,and eGA had the lowest content,furthermore,β-sheet structures were more stable in eGS and eGV than those in eGA and eGY.展开更多
基金Supported by the 2016 Major Collaborative Innovation Program of the Chinese Academy of Medical Sciences(2016-I2M-1004)
文摘Objective To evaluate senile plaque formation and compare the sensitivity of three differentβ-amyloid(Aβ)labeling methods(antibody staining,Gallyas silver staining,and thioflavin-S staining)to detect Aβdeposition.Methods APPswe/PSEN1dE9 transgenic mice(APP/PS1)of different ages were used to examine spatiotemporal changes in Aβplaque deposition.Antibody staining,Gallyas silver staining,and thioflavin-S staining were used to detect Aβplaque deposition in the same brain region of adjacent slices from model mice,and the results were compared.Results With aging,Aβplaques first appeared in the cortex and then the deposition increased throughout the whole brain.Significantly greater plaque deposition was detected by 6E10 antibody than that analyzed with Gallyas silver staining or thioflavin-S staining(P<0.05).Plaque deposition did not show significant difference between the APP/PS1 mice brains assayed with Gallyas silver staining and ones with thioflavin-S staining(P=0.0033).Conclusions The APP/PS1 mouse model of Alzheimer’s disease could mimick the progress of Aβplaques occurred in patients with Alzheimer’s disease.Antibody detection of Aβdeposition may be more sensitive than chemical staining methods.
基金financially supported by the National Natural Science Foundation of China(No. 21475091)the Science andTechnology Department of Sichuan Province(No. 2015GZ0301)
文摘G-quadruplex ligands have been accepted as potential therapeutic agents for anticancer treatment. Thioflavin T （ThT）, a highly selective G-quadruplex ligand, can bind G-quadruplex with a fluorescent light-up signal change and high specificity against DNA duplex. However, there are still different opinions that ThT induces/stabilizes G-quadruplex foldings/topologies in human telomere sequence. Here, a sensitive single-molecule nanopore technology was utilized to analyze the interactions between human telomeric DNA （Tel DNA） and ThT. Both translocation time and current blockade were measured to investigate the translocation behaviors. Furthermore, the effects of metal ion （K~ and Na~） and pH on the translocation behaviors were studied. Based on the single-molecule level analysis, there are some conclusions： （1） In the electrolyte solution containing 50 mmol/L I（Cl and 450 mmol/L NaCl, ThT can bind strongly with Tel DNA but nearly does not change the G-quadruplex form; （2） in the presence of high concentration K~, the ThT binding induces the structural change of hybrid G-quadruplex into antiparallel topology with an enhanced structural stability; （3） In either alkaline or acidic buffer, G-quadruplex form will change in certain degree. All above conclusions are helpful to deeply understand the interaction behaviors between Tel DNA and ThT. This nanopore platform, investigating G-quadruplex ligands at the single-molecule level, has great potential for the design of new drugs and sensors.
基金National Natural Science Foundation of China (No. 51075422)Natural Science Foundation of Jiangsu Province,China(No. BK2009147,No. BK2010253)+1 种基金Society Development Foundation of Suzhou City,China (No. SYG201001)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘The molecular conformations of four silk fibroin crystalline analogues [GAGAG-X] 16(G,Gly;A,Ala;X=Ala,Ser,Tyr or Val,designated eGA,eGS,eGY or eGV),carried out using molecular design and expressed by Escherichia coil(E.coli),were evaluated by Raman spectra analysis.The abilities of forming β-sheet structure were determined by thioflavin T(ThT) fluorescence spectra analysis.In terms of molecular conformation,except eGY that could not form significant typical molecular conformation,eGS and eGV were mainly composed of β-sheets while eGA tended to form β-turn.β-turn was also present in eGY and absent in eGS and eGV.In terms of β-sheet structure,eGS had the highest β-sheet content,followed by eGV,and eGA had the lowest content,furthermore,β-sheet structures were more stable in eGS and eGV than those in eGA and eGY.
