Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40,...Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40, the details of NK's capture of various Aβ species and reduction of plasma Aβ42/Aβ40 are uncharacterized. In this study, the Aβ42/Aβ40-degrading ability of NK was investigated using five Aβs and AD model mice. The C-terminal region of Aβ42/Aβ40(Gly29 to Val40)was primarily required for NK capture, and the integrated conformation in Aβ42/Aβ40 aggregates was a more efficient target for NK catalysis. Further, suspended Aβ42/Aβ40 oligomers were more easily captured by NK than suspended Aβ42/Aβ40 fibrils, while deposited Aβ42/Aβ40 fibrils recruited more NK than deposited Aβ42/Aβ40 oligomers. Although most NK was likely lost during NK uptake and/or entry into the blood, a small fraction of NK showed good plasma Aβ42/Aβ40-degrading efficacy after entering the blood due to NK's stability in the plasma of AD mice for at least 9 days. It was concluded that oral administration of NK is a feasible approach for peripheral Aβ42/Aβ40 clearance. This implies that NK might serve as an anti-Aβ42 agent for the treatment of Aβ42/Aβ40-related diseases such as AD.展开更多
Amyloid 13-peptide, a major component of senile plaques in Alzheimer＇s disease, has been implicated in neuronal cell death and cognitive impairment. Recently, studies have shown that the pathogenesis of cerebral isch...Amyloid 13-peptide, a major component of senile plaques in Alzheimer＇s disease, has been implicated in neuronal cell death and cognitive impairment. Recently, studies have shown that the pathogenesis of cerebral ischemia is closely linked with Alzheimer＇s disease. In this study, a rat model of global cerebral ischemia-reperfusion injury was established via occlusion of four arteries; meanwhile, fibrillar amyloid [3-peptide was injected into the rat lateral ventricle. The Morris water maze test and histological staining revealed that administration of amyloid 13-peptide could further aggravate impairments to learning and memory and neuronal cell death in the hippocampus of rats subjected to cerebral ischemia-reperfusion injury. Western blot showed that phosphorylation of tau protein and the activity of glycogen synthase kinase 313 were significantly stronger in cerebral ischemia-reperfusion injury rats subjected to amyloid [3-peptide administration than those undergo- ing cerebral ischemia-repetfusion or amyloid 13-peptide administration alone. Conversely, the activ- ity of protein phosphatase 2A was remarkably reduced in rats with cerebral ischemia-reperfusion injury following amyloid 13-peptide administration. These findings suggest that amyloid 13-peptide can potentiate tau phosphorylation induced by cerebral ischemia-reperfusion and thereby aggravate cognitive impairment.展开更多
The inhibitory mechanism of copper（Ⅱ） on the aggegation of amyloid β-peptide （Aβ） was investigated by molecular dynamics simulations. The binding mode ofcopper（Ⅱ） with Aβ is characterized by the imidazole n...The inhibitory mechanism of copper（Ⅱ） on the aggegation of amyloid β-peptide （Aβ） was investigated by molecular dynamics simulations. The binding mode ofcopper（Ⅱ） with Aβ is characterized by the imidazole nitrogen atom, Nπ, of the histidine residue H 13, acting as the anchoring site, and the backbone＇s deprotoned amide nitogen atoms as the main binding sites. Drove by the coordination bonds and their induced hydrogen bond net, the conformations of Aβ converted from β-sheet non-β-sheet conformations, which destabilized the aggregation of Aβ into fibrils.展开更多
Objective： To improve DC-based tumor vaccination, we studied whether dendritic ceils （DCs） which cocultured with H22 liver cancer cells-derived heat shock protein （HSP） glycoprotein 96 （gp96） affect the T cell-...Objective： To improve DC-based tumor vaccination, we studied whether dendritic ceils （DCs） which cocultured with H22 liver cancer cells-derived heat shock protein （HSP） glycoprotein 96 （gp96） affect the T cell-activating potential in vitro and the induction of tumor immunity in vivo. Methods： Maturation of murine bone marrow-derived DC was induced by GM-CSF plus IL-4, which mimiced the immunostimulatory effect of DC. Cocultured DC and gp96-peptide complexes were used to vaccine H22 liver cancer cells of mice. Using murine models we compared the immunogenecity of DC modified by gp96-peptides complexes derived from murine liver cancer cells alone or inactive tumor cells. To verify the specificity of the vaccine, in vitro assays were executed. Serum cytokine levels were quantified to explore the supposed pathway of DC modified by gp96 peptide complexes and its effect on antitumor immune response. Results： DC modified by gp96-peptide complexes can activate spleen lymphocyte and the latter can specifically kill H22 cells but not Ehrilich ascites carcinoma cells. Modified DC can induce potent tumor-antigenspecific immune response, augment the proliferation of Thl cells, and inhibit tumor growth. Conclusion： In this study, we have developed a novel DC-mediated tumor vaccine by combing the gp96 antigenic peptides complexes and inducing immune response against specific tumor cells, gp96 can be identified as a potent DC activator.展开更多
Objective： To investigate the antitumor effect of dendritic cell （DC） modified by gp96-peptide complexes both in vitro and in vivo. Methods：Gp96-peptide complexes were acquired from H22 liver cancer cells in mice....Objective： To investigate the antitumor effect of dendritic cell （DC） modified by gp96-peptide complexes both in vitro and in vivo. Methods：Gp96-peptide complexes were acquired from H22 liver cancer cells in mice. DC were cultured from bone marrow cells and modified by gp96-peptide complexes. Spleen lymphocytes of mice were activated by modified DC and the cytotoxicity were detected by ^51Cr release method. Modified DC, gp96-peptide complexes and inactivated H22 cells were injected into mice bearing H22 liver cancer cells to observe the levels of IL-10, IFN-y in serum and the alteration of proportions of CD8^＋-IFNy^＋ and CD8^＋-IL-10^＋ cells, CD4^＋-IFNy^＋ and CD4^＋-IL-10^＋ cells. Results： DC modified by gp96-peptide complexes can activate spleen lymphocyte and the latter can specifically kill H22 cells but not Ehrilich ascites carcinoma cells. Modified DC can improve the host＇s antitumor immune response and the proportions of Thl cells, inhibiting tumor growth. Conclusion： Gp96-peptide complexes can activate DC effectively, making DC a good vaccine.展开更多
BACKGROUND： The pharmacological actions of Panax notoginseng saponins （PNS） lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheime...BACKGROUND： The pharmacological actions of Panax notoginseng saponins （PNS） lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheimer＇s disease. OBJECTIVE： Using the Morris water maze, immunohistochemistry, real-time PCR and RT-PCR, this study aimed to measure improvement in spatial learning, memory, expression of amyloid precursor protein （App） and β -amyloid （A β ）, to investigate the mechanism of action of PNS in the treatment of AD in the senescence accelerated mouse-prone 8 （SAMP8） and compare the effects with huperzine A. DESIGN, TIME AND SETTING： A completely randomized grouping design, controlled animal experiment was performed in the Center for Research ＆ Development of New Drugs, Guangxi Traditional Chinese Medical University from July 2005 to April 2007. MATERIALS： Sixty male SAMP8 mice, aged 3 months, purchased from Tianjin Chinese Traditional Medical University of China, were divided into four groups： PNS high-dosage group, PNS low-dosage group, huperzine A group and control group. PNS was provided by Weihe Pharmaceutical Co., Ltd. （batch No.： Z53021485, Yuxi, Yunan Province, China）. Huperzine A was provided by Zhenyuan Pharmaceutical Co., Ltd. （batch No.： 20040801, Zhejiang, China）. METHODS： The high-dosage group and low-dosage group were treated with 93.50 and 23.38 mg/kg PNS respectively per day and the huperzine A group was treated with 0.038 6 mg/kg huperzine A per day, all by intragastric administration, for 8 consecutive weeks. The same volume of double distilled water was given to the control group. MAIN OUTCOME MEASURES： After drug administration, learning and memory abilities were assessed by place navigation and spatial probe tests. The recording indices consisted of escape latency （time-to-platform）, and the percentage of swimming time spent in each quadrant. The number of A β 1-40, A β 1-42 and App immunopositive neurons in the brains of SAMP8 mice was analyzed by immunohistochemistry. The mRNA content ofApp, tau, acetylcholinesterase, and synaptophysin （Syp） was tested by real time PCR and RT-PCR. RESULTS： The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β 1-40, A β 1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. CONCLUSION： These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer＇s disease. The therapeutic effects of PNS for Alzheimer＇s disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.展开更多
Beta amyloid (Aβ) aggregation has been characterized to be responsible for several amyloid diseases. Fourier transform infrared (FTIR) spectroscopy, fluorescence, and atomic force microscopy (AFM) are used to investi...Beta amyloid (Aβ) aggregation has been characterized to be responsible for several amyloid diseases. Fourier transform infrared (FTIR) spectroscopy, fluorescence, and atomic force microscopy (AFM) are used to investigate induced changes in the secondary structure of Aβ upon thermal denaturation and interaction with propofol and L-arginine. Spectral analysis has revealed an effective static quenching for the intrinsic fluorescence of Aβ by propofol and l-arginine with binding constants of 2.81 × 102 M-1 for Aβ-propofol and 0.37 × 102 M-1 for Aβ-L-arginine. Fourier self-deconvolution (FSD) technique has been used to evaluate the relative intensity changes in the spectra of the component bands in the amide I and amide II regions at different ligand’s concentration in the protein complex. The analysis showed a decrease in the intensities of the parallel beta bands of propofol and L-arginine interactions with Aβ, accompanied with an increase in the antiparallel bands for the Aβ-propofol interaction and a decrease for the Aβ-l-arginine interaction. The relative increase in peaks’ intensities at 1694 cm-1 and 1531 cm-1 for the propofol interaction is linked to the formation of oligomers in the protein.展开更多
HLA-A~*2402 is one of the most frequent HLA-A allele in Asian population.To construct HLA-A~*2402-peptide tetramers,the transmembrane and intracellular segments of HLA-A~*2402 cDNA were replaced with BSP sequence to f...HLA-A~*2402 is one of the most frequent HLA-A allele in Asian population.To construct HLA-A~*2402-peptide tetramers,the transmembrane and intracellular segments of HLA-A~*2402 cDNA were replaced with BSP sequence to form a fusion gene of sHLA-A~*2402-BSP.The sHLA-A~*2402-BSP fusion protein and β2m were high-level expressed as insoluble aggregates in E.coli,and refoided to form an HLA-A~*2402-peptide monomeric complex by dilution method in the presence of an antigenic peptide.The HLA-A~*2402-peptide monomeric complex was biotinated and tetramized to prepare HLA-A~*2402-peptide tetramer.Then using the HLA-A~*2402-peptide tetramers to detect antigen-specific cytotoxic T lymphocyte(CTL)induced by artificial antigen presenting cell (aAPC)in vitro.The results showed that HLA-A~*2402-peptide tetramer was prepared correctly,and functional in detecting antigen-specific CTL in vitro,HLA-A~*2402-peptide monomeric and its multimeric complexes are expected to provide a powerful tool for studying mechanisms of immune-related diseases in Asian populations. Cellular & Molecular Immunology.2005;2(2):145-149.展开更多
Amyloid β-peptide （Aβ） aggregation is a critical step in the pathogenesis of Alzheimer＇s disease （AD）. Inhibition of A[3 production, dissolution of existing aggregates and clearance of Aβ represent valid thera...Amyloid β-peptide （Aβ） aggregation is a critical step in the pathogenesis of Alzheimer＇s disease （AD）. Inhibition of A[3 production, dissolution of existing aggregates and clearance of Aβ represent valid therapeutic strategies against AD. Herein, a novel platinum（II）-coordinated graphitic carbon nitride （g-C3N4） nanosheet （g-C3N4@Pt） has been designed to covalently bind to Aβ and modulate the peptide＇s aggregation and toxicity. Furthermore, g-CBN4@Pt nanosheets possess high photocatalytic activity and can oxygenate Aβ upon visible light irradiation, remarkably attenuating both the aggregation potency and neurotoxicity of Aβ Due to its ability to cross the blood-brain barrier （BBB） and its good biocompatibility, g-C3N4@Pt nanosheet is a promising inhibitor of Aβ aggregation. This study may serve as a model for the engineering of novel multifunctional nanomaterials used for the treatment of AD.展开更多
Aggregation of amyloid ?-peptide (A?) into insoluble fibrils is a key pathological event in Alzheimer’s disease (AD). Under certain conditions, Cu(II) exhibits strong inhibitory ef-fect on the Zn(II)-induced aggregat...Aggregation of amyloid ?-peptide (A?) into insoluble fibrils is a key pathological event in Alzheimer’s disease (AD). Under certain conditions, Cu(II) exhibits strong inhibitory ef-fect on the Zn(II)-induced aggregation, which occurs significantly even at nearly physiological concentrations of zinc ion in vitro. Cu(II) is considered as a potential factor in the normal brain preventing A? from aggregating. The possible mechanism of the inhibitory effect of Cu(II) is in-vestigated for the first time by molecular modeling method. In the mono-ring mode, the Y10 residue promotes typical quasi-helix conformations of A?. Specially, [Cu-H13(Np)-Y10(OH)] complex forms a local 3.010 helix conformation. In the multi-ring mode, the side chains of Q15 and E11 residues collaborate harmoniously with other chelating ligands producing markedly low energies and quasi-helix conformations. [Cu-3N-Q15(O)-E11(O1)] and [Cu-H13(Np)-Y10(OH)] complex with quasi-helix conformations may prefer soluble forms in solution. In addition, hydro-gen-bond interactions may be the main driving force for A? aggregation. All the results will pro-vide helpful clues for an improved understanding of the role of Cu(II) in the pathogenesis of AD and contribute to the development of an “anti-amyloid” therapeutic strategy.展开更多
Cariogenic Streptococcus mutans(S.mutans)is a leading cause of bacterial-induced oral diseases.Current strategies to kill bacteria based on Host defense peptide(HDP)mimicking polymers hold promise to treat oral bacter...Cariogenic Streptococcus mutans(S.mutans)is a leading cause of bacterial-induced oral diseases.Current strategies to kill bacteria based on Host defense peptide(HDP)mimicking polymers hold promise to treat oral bacterial infection.Here,we explore the impact of hydrophobic subunit and chain length variation on the antibacterial and antibiofilm activity ofβ-peptide polymers.The physicochemical and biological prop-erties,such as the toxicity,the antibacterial activity,and the effect on bacterial transcription ofβ-peptide polymers,were systematically investigated with numerous techniques.The results exhibited that the op-timalβ-peptide polymer has low toxicity towards human periodontal ligament fibroblasts,andβ-peptide polymers(especially P3)have more excellent antibacterial activity against S.mutans than metronidazole.In addition,β-peptide polymers inhibited the reversible and irreversible bacterial adhesion during the formation of biofilms.The polymer can promote biofilm dispersion by decreasing the hydrophobicity of bacterial cells after adhering to cell surfaces.Analysis of the transcriptome for S.mutans treated withβ-peptide polymers demonstrated thatβ-peptide polymers could reduce the cariogenicity of S.mutans by impacting the transcription of the energy and acid metabolism-related genes.β-peptide polymers are promising antimicrobial agents in clinical dentistry due to their high antibacterial efficiency and low tox-icity.展开更多
Collagenα3(IV)chains are one of the major constituent components of the basement membrane in the mammalian testis.Studies have shown that biologically active fragments,such as noncollagenase domain(NC1)-peptide,can b...Collagenα3(IV)chains are one of the major constituent components of the basement membrane in the mammalian testis.Studies have shown that biologically active fragments,such as noncollagenase domain(NC1)-peptide,can be released from the C-terminal region of collagenα3(IV)chains,possibly through the proteolytic action of metalloproteinase 9(MMP9).NC1-peptide was shown to promote blood-testis barrier(BTB)remodeling and fully developed spermatid(e.g.,sperm)release from the seminiferous epithelium because this bioactive peptide was capable of perturbing the organization of both actin-and microtubule(MT)-based cytoskeletons at the Sertoli cell-cell and also Sertoli-spermatid interface,the ultrastructure known as the basal ectoplasmic specialization(ES)and apical ES,respectively.More importantly,recent studies have shown that this NC1-peptide-induced effects on cytoskeletal organization in the testis are mediated through an activation of mammalian target of rapamycin complex 1/ribosomal protein S6/transforming retrovirus Akt1/2 protein(mTORC1/rpS6/Akt1/2)signaling cascade,involving an activation of cell division control protein 42 homolog(Cdc42)GTPase,but not Ras homolog family member A GTPase(RhoA),and the participation of end-binding protein 1(EB1),a microtubule plus(+)end tracking protein(+TIP),downstream.Herein,we critically evaluate these findings,providing a critical discussion by which the basement membrane modulates spermatogenesis through one of its locally generated regulatory peptides in the testis.展开更多
Amyloid beta-peptide 1-42(Aβ1-42)is one of the biomarkers of Alzheimer's disease,and its selective capture and quantitative detection are important for diagnosis and treatment of Alzheimer's disease.Herein,co...Amyloid beta-peptide 1-42(Aβ1-42)is one of the biomarkers of Alzheimer's disease,and its selective capture and quantitative detection are important for diagnosis and treatment of Alzheimer's disease.Herein,copper(Ⅱ)ions-immobilized virus-like hollow covalent organic frameworks(V-HCOFs@Cu^(2+))were synthesized by a facile approach.The as-prepared V-HCOFs@Cu^(2+)showed unique morphology,ultra-high specific surface(2552 m^(2)/g),uniform mesoporous structure(3.2 nm),superior chemical stability and abundant binding sites.Based on these excellent properties,the V-HCOFs@Cu^(2+)could be adopted as an ideal enrichment probe for highly efficient capture of Aβ1-42,exhibiting high adsorption capacity(320 mg/g),and fast adsorption equilibration time(3 min).In addition,an attractive approach of the V-HCOFs@Cu^(2+)-based matrix-assisted laser desorption/ionization mass spectrometry(MALDI-MS)was developed for the rapid screening and quantitative analysis of Aβ1-42 in human serum by using C-peptide as an internal standard,which exhibited low limit of detection(LOD,0.2 fmol/μL),and satisfactory recovery.This work provides an alternative solution for enrichment of biomarkers and also offers the potential applications of COFs in clinical analysis.展开更多
Metal ions are involved in Aβ aggregate deposition and neurotoxicity via various processes, including acceleration of Aβ aggregation, disruption of normal metal homeostasis, and formation of reactive oxygen species ...Metal ions are involved in Aβ aggregate deposition and neurotoxicity via various processes, including acceleration of Aβ aggregation, disruption of normal metal homeostasis, and formation of reactive oxygen species （ROS）. Although metal chelation is a promising therapeutic strategy for Alzheimer＇s disease （AD）, the widespread use of chelation therapy faces a significant problem; namely, it is difficult to differentiate toxic metals associated with Aβ plaques from those required by normal metal homeostasis. Furthermore, the multifactorial nature of AD and the current lack of an accepted unitary theory to account for AD neurodegeneration also restrict AD treatment through a single therapeutic strategy. This paper presents a novel bifunctional platform by integrating nonpharmacological and pharmacological cues into one system for AD treatment. This electrically responsive drug release platform, based on conducting polymer polypyrrole （PPy） incorporated with graphene-mesoporous silica nanohybrids （GSN） nanoreserviors, could realize on-demand controlled drug delivery with spatial and temporal control. Electrochemical stimulation can treat peripheral nerve injury （PNI） to stimulate neurite outgrowth. This novel system can also effectively inhibit Aβ aggregate formation, decrease cellular ROS, and protect cells from Aβ-related toxicity. The purpose of this research is to promote the design of noninvasive remote-controlled multifunctional systems for AD treatment.展开更多
Recent clinical and epidemiological research has shown that insulin is associated with the pathological mechanisms of Alzheimer＇s disease （AD） and can protect against the oxidative stress triggered by amyloidq3 pep...Recent clinical and epidemiological research has shown that insulin is associated with the pathological mechanisms of Alzheimer＇s disease （AD） and can protect against the oxidative stress triggered by amyloidq3 peptide （Aβ3）. Herein, we present a systematic study on how the cross-fibrillation of insulin and Aβ is influenced by the surface chirality of an interface designed to mimic their aggregation on the cytomembrane. Intriguingly, the surface chirality strongly affected the aggregation kinetics, structure, morphologβ and cellular responses of the cross-aggregates of insulin and Aβ. On a D-phenylalanine- modified surface, Aβ induced insulin to co-aggregate into β-sheet-rich fibrils and cross-fibrils that showed a pronounced cellular toxicity. However, on an L-phenylalanine-modified surface, insulin and Aβ3 formed non-toxic amorphous aggregates. Our work indicates that surface chirality can influence the cross- fibrillation of Aβ and insulin as well as the cytotoxicity of their aggregates.展开更多
The peptides mixture was prepared from tumor cells by freezing-thawing cells, precipitation by heating, followed by acidification of the solution. The activation and proliferation of mouse splenocytes by HSP70-peptide...The peptides mixture was prepared from tumor cells by freezing-thawing cells, precipitation by heating, followed by acidification of the solution. The activation and proliferation of mouse splenocytes by HSP70-peptide complex, formed by the binding of HSP70 and peptides in vitro, were observed, so was the specific cytotoxicity of the proliferative lymphocytes to tumor cells. The phenotypes of the proliferative lymphocytes were analyzed by a flow cytometer. BALB/c mice inoculated with H22 hepatocarcinoma cells in peritoneal cavity or hind thigh were immunized by injection with HSP70-peptides complex to observe the inhibitory effect of the immunization on tumor and lifetime of tumor-bearing mice. On the other hand, blood samples were collected from the immunized mice to check the functions of liver and kidney. The results showed that the peptides mixture from tumor cells contained tumor-specific antigen peptides which could be presented by HSP70 to activate lymphocytes in vitro, the proliferative lymphocytes were T cells which were specifically cytotoxic to tumor cells, the in vivo growth of both ascitic and solid carcinoma could be suppressed by immunization with HSP70-peptides and the lifetime of tumor-bearing mice was prolonged, the in vivo immunization with HSP70-H22-peptides had no impact on the function of mouse liver and kidney, suggesting that there was no occurrence of autoimmunity in vivo after immunization.展开更多
基金supported by the National Natural Science Foundation of China Program (No. 31970883)。
文摘Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40, the details of NK's capture of various Aβ species and reduction of plasma Aβ42/Aβ40 are uncharacterized. In this study, the Aβ42/Aβ40-degrading ability of NK was investigated using five Aβs and AD model mice. The C-terminal region of Aβ42/Aβ40(Gly29 to Val40)was primarily required for NK capture, and the integrated conformation in Aβ42/Aβ40 aggregates was a more efficient target for NK catalysis. Further, suspended Aβ42/Aβ40 oligomers were more easily captured by NK than suspended Aβ42/Aβ40 fibrils, while deposited Aβ42/Aβ40 fibrils recruited more NK than deposited Aβ42/Aβ40 oligomers. Although most NK was likely lost during NK uptake and/or entry into the blood, a small fraction of NK showed good plasma Aβ42/Aβ40-degrading efficacy after entering the blood due to NK's stability in the plasma of AD mice for at least 9 days. It was concluded that oral administration of NK is a feasible approach for peripheral Aβ42/Aβ40 clearance. This implies that NK might serve as an anti-Aβ42 agent for the treatment of Aβ42/Aβ40-related diseases such as AD.
基金supported by the National High Technology Research and Development Program of China("863"Program),No.2012AA020905the National Natural Science Foundation of China,No.81171143 and30971011+1 种基金National Natural Science Foundation of China(NSFC)/Research Grants Council(RGC) Joint Research Scheme,No.81161160570TsinghuaYue-Yuen Medical Sciences Fund
文摘Amyloid 13-peptide, a major component of senile plaques in Alzheimer＇s disease, has been implicated in neuronal cell death and cognitive impairment. Recently, studies have shown that the pathogenesis of cerebral ischemia is closely linked with Alzheimer＇s disease. In this study, a rat model of global cerebral ischemia-reperfusion injury was established via occlusion of four arteries; meanwhile, fibrillar amyloid [3-peptide was injected into the rat lateral ventricle. The Morris water maze test and histological staining revealed that administration of amyloid 13-peptide could further aggravate impairments to learning and memory and neuronal cell death in the hippocampus of rats subjected to cerebral ischemia-reperfusion injury. Western blot showed that phosphorylation of tau protein and the activity of glycogen synthase kinase 313 were significantly stronger in cerebral ischemia-reperfusion injury rats subjected to amyloid [3-peptide administration than those undergo- ing cerebral ischemia-repetfusion or amyloid 13-peptide administration alone. Conversely, the activ- ity of protein phosphatase 2A was remarkably reduced in rats with cerebral ischemia-reperfusion injury following amyloid 13-peptide administration. These findings suggest that amyloid 13-peptide can potentiate tau phosphorylation induced by cerebral ischemia-reperfusion and thereby aggravate cognitive impairment.
基金This work was supported by the National Natural Science Foundation of China(Nos.30470408 and 20637010).
文摘The inhibitory mechanism of copper（Ⅱ） on the aggegation of amyloid β-peptide （Aβ） was investigated by molecular dynamics simulations. The binding mode ofcopper（Ⅱ） with Aβ is characterized by the imidazole nitrogen atom, Nπ, of the histidine residue H 13, acting as the anchoring site, and the backbone＇s deprotoned amide nitogen atoms as the main binding sites. Drove by the coordination bonds and their induced hydrogen bond net, the conformations of Aβ converted from β-sheet non-β-sheet conformations, which destabilized the aggregation of Aβ into fibrils.
基金Supported by the National Natural Science Foundation of China (No. 30200369)
文摘Objective： To improve DC-based tumor vaccination, we studied whether dendritic ceils （DCs） which cocultured with H22 liver cancer cells-derived heat shock protein （HSP） glycoprotein 96 （gp96） affect the T cell-activating potential in vitro and the induction of tumor immunity in vivo. Methods： Maturation of murine bone marrow-derived DC was induced by GM-CSF plus IL-4, which mimiced the immunostimulatory effect of DC. Cocultured DC and gp96-peptide complexes were used to vaccine H22 liver cancer cells of mice. Using murine models we compared the immunogenecity of DC modified by gp96-peptides complexes derived from murine liver cancer cells alone or inactive tumor cells. To verify the specificity of the vaccine, in vitro assays were executed. Serum cytokine levels were quantified to explore the supposed pathway of DC modified by gp96 peptide complexes and its effect on antitumor immune response. Results： DC modified by gp96-peptide complexes can activate spleen lymphocyte and the latter can specifically kill H22 cells but not Ehrilich ascites carcinoma cells. Modified DC can induce potent tumor-antigenspecific immune response, augment the proliferation of Thl cells, and inhibit tumor growth. Conclusion： In this study, we have developed a novel DC-mediated tumor vaccine by combing the gp96 antigenic peptides complexes and inducing immune response against specific tumor cells, gp96 can be identified as a potent DC activator.
基金Supported by National Natural Science Foundation of Chi-na (NO.30200369)
文摘Objective： To investigate the antitumor effect of dendritic cell （DC） modified by gp96-peptide complexes both in vitro and in vivo. Methods：Gp96-peptide complexes were acquired from H22 liver cancer cells in mice. DC were cultured from bone marrow cells and modified by gp96-peptide complexes. Spleen lymphocytes of mice were activated by modified DC and the cytotoxicity were detected by ^51Cr release method. Modified DC, gp96-peptide complexes and inactivated H22 cells were injected into mice bearing H22 liver cancer cells to observe the levels of IL-10, IFN-y in serum and the alteration of proportions of CD8^＋-IFNy^＋ and CD8^＋-IL-10^＋ cells, CD4^＋-IFNy^＋ and CD4^＋-IL-10^＋ cells. Results： DC modified by gp96-peptide complexes can activate spleen lymphocyte and the latter can specifically kill H22 cells but not Ehrilich ascites carcinoma cells. Modified DC can improve the host＇s antitumor immune response and the proportions of Thl cells, inhibiting tumor growth. Conclusion： Gp96-peptide complexes can activate DC effectively, making DC a good vaccine.
基金the National Natural Science Foundation of China, No: 30560189
文摘BACKGROUND： The pharmacological actions of Panax notoginseng saponins （PNS） lie in removing free radicals, anti-inflammation and anti-oxygenation. It can also improve memory and behavior in rat models of Alzheimer＇s disease. OBJECTIVE： Using the Morris water maze, immunohistochemistry, real-time PCR and RT-PCR, this study aimed to measure improvement in spatial learning, memory, expression of amyloid precursor protein （App） and β -amyloid （A β ）, to investigate the mechanism of action of PNS in the treatment of AD in the senescence accelerated mouse-prone 8 （SAMP8） and compare the effects with huperzine A. DESIGN, TIME AND SETTING： A completely randomized grouping design, controlled animal experiment was performed in the Center for Research ＆ Development of New Drugs, Guangxi Traditional Chinese Medical University from July 2005 to April 2007. MATERIALS： Sixty male SAMP8 mice, aged 3 months, purchased from Tianjin Chinese Traditional Medical University of China, were divided into four groups： PNS high-dosage group, PNS low-dosage group, huperzine A group and control group. PNS was provided by Weihe Pharmaceutical Co., Ltd. （batch No.： Z53021485, Yuxi, Yunan Province, China）. Huperzine A was provided by Zhenyuan Pharmaceutical Co., Ltd. （batch No.： 20040801, Zhejiang, China）. METHODS： The high-dosage group and low-dosage group were treated with 93.50 and 23.38 mg/kg PNS respectively per day and the huperzine A group was treated with 0.038 6 mg/kg huperzine A per day, all by intragastric administration, for 8 consecutive weeks. The same volume of double distilled water was given to the control group. MAIN OUTCOME MEASURES： After drug administration, learning and memory abilities were assessed by place navigation and spatial probe tests. The recording indices consisted of escape latency （time-to-platform）, and the percentage of swimming time spent in each quadrant. The number of A β 1-40, A β 1-42 and App immunopositive neurons in the brains of SAMP8 mice was analyzed by immunohistochemistry. The mRNA content ofApp, tau, acetylcholinesterase, and synaptophysin （Syp） was tested by real time PCR and RT-PCR. RESULTS： The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β 1-40, A β 1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group （P 〈 0.05）. CONCLUSION： These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer＇s disease. The therapeutic effects of PNS for Alzheimer＇s disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.
文摘Beta amyloid (Aβ) aggregation has been characterized to be responsible for several amyloid diseases. Fourier transform infrared (FTIR) spectroscopy, fluorescence, and atomic force microscopy (AFM) are used to investigate induced changes in the secondary structure of Aβ upon thermal denaturation and interaction with propofol and L-arginine. Spectral analysis has revealed an effective static quenching for the intrinsic fluorescence of Aβ by propofol and l-arginine with binding constants of 2.81 × 102 M-1 for Aβ-propofol and 0.37 × 102 M-1 for Aβ-L-arginine. Fourier self-deconvolution (FSD) technique has been used to evaluate the relative intensity changes in the spectra of the component bands in the amide I and amide II regions at different ligand’s concentration in the protein complex. The analysis showed a decrease in the intensities of the parallel beta bands of propofol and L-arginine interactions with Aβ, accompanied with an increase in the antiparallel bands for the Aβ-propofol interaction and a decrease for the Aβ-l-arginine interaction. The relative increase in peaks’ intensities at 1694 cm-1 and 1531 cm-1 for the propofol interaction is linked to the formation of oligomers in the protein.
基金This study was supported by National Key Basic Research Program of China(No.CB 510008)National Natural Science Foundation of China(No.30271201).
文摘HLA-A~*2402 is one of the most frequent HLA-A allele in Asian population.To construct HLA-A~*2402-peptide tetramers,the transmembrane and intracellular segments of HLA-A~*2402 cDNA were replaced with BSP sequence to form a fusion gene of sHLA-A~*2402-BSP.The sHLA-A~*2402-BSP fusion protein and β2m were high-level expressed as insoluble aggregates in E.coli,and refoided to form an HLA-A~*2402-peptide monomeric complex by dilution method in the presence of an antigenic peptide.The HLA-A~*2402-peptide monomeric complex was biotinated and tetramized to prepare HLA-A~*2402-peptide tetramer.Then using the HLA-A~*2402-peptide tetramers to detect antigen-specific cytotoxic T lymphocyte(CTL)induced by artificial antigen presenting cell (aAPC)in vitro.The results showed that HLA-A~*2402-peptide tetramer was prepared correctly,and functional in detecting antigen-specific CTL in vitro,HLA-A~*2402-peptide monomeric and its multimeric complexes are expected to provide a powerful tool for studying mechanisms of immune-related diseases in Asian populations. Cellular & Molecular Immunology.2005;2(2):145-149.
基金This work was supported by the National Basic Research Program of China （Nos. 2012CB720602 and 2011CB936004）, and the National Natural Science Foundation of China （Nos. 21210002, 21431007, and 21533008）.
文摘Amyloid β-peptide （Aβ） aggregation is a critical step in the pathogenesis of Alzheimer＇s disease （AD）. Inhibition of A[3 production, dissolution of existing aggregates and clearance of Aβ represent valid therapeutic strategies against AD. Herein, a novel platinum（II）-coordinated graphitic carbon nitride （g-C3N4） nanosheet （g-C3N4@Pt） has been designed to covalently bind to Aβ and modulate the peptide＇s aggregation and toxicity. Furthermore, g-CBN4@Pt nanosheets possess high photocatalytic activity and can oxygenate Aβ upon visible light irradiation, remarkably attenuating both the aggregation potency and neurotoxicity of Aβ Due to its ability to cross the blood-brain barrier （BBB） and its good biocompatibility, g-C3N4@Pt nanosheet is a promising inhibitor of Aβ aggregation. This study may serve as a model for the engineering of novel multifunctional nanomaterials used for the treatment of AD.
基金supported by the National Natural Science Foundation of China(Grant No.30470408).
文摘Aggregation of amyloid ?-peptide (A?) into insoluble fibrils is a key pathological event in Alzheimer’s disease (AD). Under certain conditions, Cu(II) exhibits strong inhibitory ef-fect on the Zn(II)-induced aggregation, which occurs significantly even at nearly physiological concentrations of zinc ion in vitro. Cu(II) is considered as a potential factor in the normal brain preventing A? from aggregating. The possible mechanism of the inhibitory effect of Cu(II) is in-vestigated for the first time by molecular modeling method. In the mono-ring mode, the Y10 residue promotes typical quasi-helix conformations of A?. Specially, [Cu-H13(Np)-Y10(OH)] complex forms a local 3.010 helix conformation. In the multi-ring mode, the side chains of Q15 and E11 residues collaborate harmoniously with other chelating ligands producing markedly low energies and quasi-helix conformations. [Cu-3N-Q15(O)-E11(O1)] and [Cu-H13(Np)-Y10(OH)] complex with quasi-helix conformations may prefer soluble forms in solution. In addition, hydro-gen-bond interactions may be the main driving force for A? aggregation. All the results will pro-vide helpful clues for an improved understanding of the role of Cu(II) in the pathogenesis of AD and contribute to the development of an “anti-amyloid” therapeutic strategy.
基金supported by the National Natural Science Foundation of China(No.51871050)the National Natural Science Foundation of China(No.U2106206)+3 种基金the Natural Science Foundation of Liaoning Province(No.20180510041)the Liaon-ing Revitalization Talents Program(No.XLYC1907158)the Gen-eral Project of Natural Science Foundation of Science and Tech-nology Department of Liaoning Province(No.2021-MS-308)the Fundamental Research Funds for the Central Universities(No.N2120007).
文摘Cariogenic Streptococcus mutans(S.mutans)is a leading cause of bacterial-induced oral diseases.Current strategies to kill bacteria based on Host defense peptide(HDP)mimicking polymers hold promise to treat oral bacterial infection.Here,we explore the impact of hydrophobic subunit and chain length variation on the antibacterial and antibiofilm activity ofβ-peptide polymers.The physicochemical and biological prop-erties,such as the toxicity,the antibacterial activity,and the effect on bacterial transcription ofβ-peptide polymers,were systematically investigated with numerous techniques.The results exhibited that the op-timalβ-peptide polymer has low toxicity towards human periodontal ligament fibroblasts,andβ-peptide polymers(especially P3)have more excellent antibacterial activity against S.mutans than metronidazole.In addition,β-peptide polymers inhibited the reversible and irreversible bacterial adhesion during the formation of biofilms.The polymer can promote biofilm dispersion by decreasing the hydrophobicity of bacterial cells after adhering to cell surfaces.Analysis of the transcriptome for S.mutans treated withβ-peptide polymers demonstrated thatβ-peptide polymers could reduce the cariogenicity of S.mutans by impacting the transcription of the energy and acid metabolism-related genes.β-peptide polymers are promising antimicrobial agents in clinical dentistry due to their high antibacterial efficiency and low tox-icity.
基金This work was supported in part by grants from the National Institutes of Health(NICHD,R01 HD056034 to CYC)the National Natural Science Foundation of China(NSFCNo.81730042 to RSG).
文摘Collagenα3(IV)chains are one of the major constituent components of the basement membrane in the mammalian testis.Studies have shown that biologically active fragments,such as noncollagenase domain(NC1)-peptide,can be released from the C-terminal region of collagenα3(IV)chains,possibly through the proteolytic action of metalloproteinase 9(MMP9).NC1-peptide was shown to promote blood-testis barrier(BTB)remodeling and fully developed spermatid(e.g.,sperm)release from the seminiferous epithelium because this bioactive peptide was capable of perturbing the organization of both actin-and microtubule(MT)-based cytoskeletons at the Sertoli cell-cell and also Sertoli-spermatid interface,the ultrastructure known as the basal ectoplasmic specialization(ES)and apical ES,respectively.More importantly,recent studies have shown that this NC1-peptide-induced effects on cytoskeletal organization in the testis are mediated through an activation of mammalian target of rapamycin complex 1/ribosomal protein S6/transforming retrovirus Akt1/2 protein(mTORC1/rpS6/Akt1/2)signaling cascade,involving an activation of cell division control protein 42 homolog(Cdc42)GTPase,but not Ras homolog family member A GTPase(RhoA),and the participation of end-binding protein 1(EB1),a microtubule plus(+)end tracking protein(+TIP),downstream.Herein,we critically evaluate these findings,providing a critical discussion by which the basement membrane modulates spermatogenesis through one of its locally generated regulatory peptides in the testis.
基金supported by a grant from the National Natural Science Foundation of China(Nos.21974021,22036001,and 91843301).
文摘Amyloid beta-peptide 1-42(Aβ1-42)is one of the biomarkers of Alzheimer's disease,and its selective capture and quantitative detection are important for diagnosis and treatment of Alzheimer's disease.Herein,copper(Ⅱ)ions-immobilized virus-like hollow covalent organic frameworks(V-HCOFs@Cu^(2+))were synthesized by a facile approach.The as-prepared V-HCOFs@Cu^(2+)showed unique morphology,ultra-high specific surface(2552 m^(2)/g),uniform mesoporous structure(3.2 nm),superior chemical stability and abundant binding sites.Based on these excellent properties,the V-HCOFs@Cu^(2+)could be adopted as an ideal enrichment probe for highly efficient capture of Aβ1-42,exhibiting high adsorption capacity(320 mg/g),and fast adsorption equilibration time(3 min).In addition,an attractive approach of the V-HCOFs@Cu^(2+)-based matrix-assisted laser desorption/ionization mass spectrometry(MALDI-MS)was developed for the rapid screening and quantitative analysis of Aβ1-42 in human serum by using C-peptide as an internal standard,which exhibited low limit of detection(LOD,0.2 fmol/μL),and satisfactory recovery.This work provides an alternative solution for enrichment of biomarkers and also offers the potential applications of COFs in clinical analysis.
文摘Metal ions are involved in Aβ aggregate deposition and neurotoxicity via various processes, including acceleration of Aβ aggregation, disruption of normal metal homeostasis, and formation of reactive oxygen species （ROS）. Although metal chelation is a promising therapeutic strategy for Alzheimer＇s disease （AD）, the widespread use of chelation therapy faces a significant problem; namely, it is difficult to differentiate toxic metals associated with Aβ plaques from those required by normal metal homeostasis. Furthermore, the multifactorial nature of AD and the current lack of an accepted unitary theory to account for AD neurodegeneration also restrict AD treatment through a single therapeutic strategy. This paper presents a novel bifunctional platform by integrating nonpharmacological and pharmacological cues into one system for AD treatment. This electrically responsive drug release platform, based on conducting polymer polypyrrole （PPy） incorporated with graphene-mesoporous silica nanohybrids （GSN） nanoreserviors, could realize on-demand controlled drug delivery with spatial and temporal control. Electrochemical stimulation can treat peripheral nerve injury （PNI） to stimulate neurite outgrowth. This novel system can also effectively inhibit Aβ aggregate formation, decrease cellular ROS, and protect cells from Aβ-related toxicity. The purpose of this research is to promote the design of noninvasive remote-controlled multifunctional systems for AD treatment.
文摘Recent clinical and epidemiological research has shown that insulin is associated with the pathological mechanisms of Alzheimer＇s disease （AD） and can protect against the oxidative stress triggered by amyloidq3 peptide （Aβ3）. Herein, we present a systematic study on how the cross-fibrillation of insulin and Aβ is influenced by the surface chirality of an interface designed to mimic their aggregation on the cytomembrane. Intriguingly, the surface chirality strongly affected the aggregation kinetics, structure, morphologβ and cellular responses of the cross-aggregates of insulin and Aβ. On a D-phenylalanine- modified surface, Aβ induced insulin to co-aggregate into β-sheet-rich fibrils and cross-fibrils that showed a pronounced cellular toxicity. However, on an L-phenylalanine-modified surface, insulin and Aβ3 formed non-toxic amorphous aggregates. Our work indicates that surface chirality can influence the cross- fibrillation of Aβ and insulin as well as the cytotoxicity of their aggregates.
基金This work was supported by the National Natural Science Foundation of China (Grant No.39970322) Trans-Century Training Programme Foundation for Talent under the supervision of Ministry of Education of China.
文摘The peptides mixture was prepared from tumor cells by freezing-thawing cells, precipitation by heating, followed by acidification of the solution. The activation and proliferation of mouse splenocytes by HSP70-peptide complex, formed by the binding of HSP70 and peptides in vitro, were observed, so was the specific cytotoxicity of the proliferative lymphocytes to tumor cells. The phenotypes of the proliferative lymphocytes were analyzed by a flow cytometer. BALB/c mice inoculated with H22 hepatocarcinoma cells in peritoneal cavity or hind thigh were immunized by injection with HSP70-peptides complex to observe the inhibitory effect of the immunization on tumor and lifetime of tumor-bearing mice. On the other hand, blood samples were collected from the immunized mice to check the functions of liver and kidney. The results showed that the peptides mixture from tumor cells contained tumor-specific antigen peptides which could be presented by HSP70 to activate lymphocytes in vitro, the proliferative lymphocytes were T cells which were specifically cytotoxic to tumor cells, the in vivo growth of both ascitic and solid carcinoma could be suppressed by immunization with HSP70-peptides and the lifetime of tumor-bearing mice was prolonged, the in vivo immunization with HSP70-H22-peptides had no impact on the function of mouse liver and kidney, suggesting that there was no occurrence of autoimmunity in vivo after immunization.
