INTRODUCTION Peptic ulcer,as a common disease,seriouslyaffected people’s,work and life.Its occurrence,development and change have close relationshipwith the change of people’s moods.Animalexperiment proved that sign...INTRODUCTION Peptic ulcer,as a common disease,seriouslyaffected people’s,work and life.Its occurrence,development and change have close relationshipwith the change of people’s moods.Animalexperiment proved that significant changes occurredin the endocrine system of the gastric ulcer rats.展开更多
Aim: The abnormal accumulation, assembly and deposition of the amyloid β-protein (Aβ) are prominent pathological features of patients with Alzheimer’s disease (AD) and related disorders. A number of factors in the ...Aim: The abnormal accumulation, assembly and deposition of the amyloid β-protein (Aβ) are prominent pathological features of patients with Alzheimer’s disease (AD) and related disorders. A number of factors in the brain can influence Aβ accumulation and associated pathologies. The aim of the present study was to determine the consequences of deleting nitric oxide synthase (NOS) 3, the endothelial form of NOS, in Tg-5xFAD mice, a model of parenchymal AD-like amyloid pathology. Methods: Tg-5xFAD mice were bred with NOS3-/- mice. Cohorts of Tg-5xFAD mice and bigenic Tg-5xFAD/NOS3-/- mice were aged to six months followed by collection of the blood and brain tissues from the mice for biochemical and pathological analyses. Results: ELISA analyses show that the absence of NOS3 results in elevated levels of cerebral and plasma Aβ peptides in Tg-5xFAD mice. Immunohistochemical analyses show that the absence of NOS3 increased the amount of parenchymal Aβ deposition and fibrillar amyloid accumulation in Tg-5xFAD mice. The elevated levels of Aβ were not due to changes in the expression levels of transgene encoded human amyloid precursor protein (APP), endogenous β-secretase, or increased proteolytic processing of APP. Conclusions: The results from this study suggest that the loss of NOS3 activity enhances Aβ pathology in Tg-5xFAD mice. These findings are similar to previous studies of NOS2 deletion suggesting that reduced NOS activity and NO levels enhance amyloid-associated pathologies in human APP transgenic mice.展开更多
PC12 cell injury was induced using 20 μM amyloid β-protein 25-35 to establish a model of Alzheimer＇s disease. The cells were then treated with 5, 10, and 25 μM Schisandrin B. Methylthiazolyldiphenyl-tetrazolium br...PC12 cell injury was induced using 20 μM amyloid β-protein 25-35 to establish a model of Alzheimer＇s disease. The cells were then treated with 5, 10, and 25 μM Schisandrin B. Methylthiazolyldiphenyl-tetrazolium bromide assays and Hoechst 33342 staining results showed that with increasing Schisandrin B concentration, the survival rate of PC12 cells injured by amyloid β-protein 25-35 gradually increased and the rate of apoptosis gradually decreased. Reverse transcription-PCR, immunocytochemical staining and western blot results showed that with increasing Schisandrin B concentration, the mRNA and protein expression of vacuolar protein sorting 35 and amyloid precursor protein were gradually decreased. Vacuolar protein sorting 35 and amyloid precursor protein showed a consistent trend for change. These findings suggest that 5, 10, and 25 μM Schisandrin B antagonizes the cellular injury induced by amyloid β-protein 25-35 in a dose-dependent manner. This may be caused by decreasing the expression of vacuolar protein sorting 35 and amyloid precursor protein.展开更多
Amyloid β-protein(Aβ) and Tau, two common pathogenic proteins associated with Alzheimer’s disease(AD), cross-interact, and thus co-assemble into hybrid aggregates. However, molecular mechanism of the cross-interact...Amyloid β-protein(Aβ) and Tau, two common pathogenic proteins associated with Alzheimer’s disease(AD), cross-interact, and thus co-assemble into hybrid aggregates. However, molecular mechanism of the cross-interactions remains unclear. To explore the issue, docking and molecular dynamics(MD) simulations were coupled to study the cross-interactions between Aβ pentamer and Tau pentamer. Four stable hybrid decamer conformations including double layer, single layer, block, and part-in were obtained by protein-protein docking software HADDOCK 2.2. Then, MD simulations were used to explore the molecular mechanism of cross-interactions between Aβ pentamer and Tau pentamer. The results of MD simulations showed that the part-in structure was the most stable among all the above four representative ones. The binding energy between Aβ and Tau was about-759.77 kJ·mol-1in the part-in structure. Moreover, the part-in conformation would undergo conformational transition, which would improve its hydrophobicity and make the structure more compact. This work offers a structural understanding of cross-interactions between Aβ and Tau linked to AD.展开更多
目的:对阿尔茨海默病(Alzheimer s disease,AD)与血管性痴呆(vascular dementia,VD)血浆β-微管蛋白与淀粉样蛋白前体(APP)进行定量分析,分析这些指标的变化是否可以为临床诊断阿尔茨海默病提供生物学方面的帮助。方法:用蛋白免疫印迹法...目的:对阿尔茨海默病(Alzheimer s disease,AD)与血管性痴呆(vascular dementia,VD)血浆β-微管蛋白与淀粉样蛋白前体(APP)进行定量分析,分析这些指标的变化是否可以为临床诊断阿尔茨海默病提供生物学方面的帮助。方法:用蛋白免疫印迹法(Western-blot)测定11例AD、11例VD和8个正常老年人血浆β-微管蛋白和APP的水平。结果:(1)血浆APP含量AD患者(84.36±41.34)的高于VD患者(56.34±18.68)和正常人(43.25±27.67),P<0.05;(2)血浆中β-微管蛋白含量AD患者(105.91±41.25)高于VD患者(64.36±28.27)和正常人(52.25±11.11),P<0.05;(3)VD患者和正常人之间APP和β-微管蛋白比较无明显差异(P>0.05)。(4)Pear-son相关分析显示:血浆中APP和β-微管蛋白含量可能存在一定的相关性,相关系数为0.451(P<0.05)。结论:AD患者血浆APP和β-微管蛋白含量明显高于正常人和VD患者,对AD患者血浆APP和β-微管蛋白含量的测定对AD的诊断可能具有一定的意义。展开更多
Amyloid-β （Aβ） protein aggregation is the main hallmark of Alzheimer＇s disease （AD）. Inhibition of Aft fibrillation is thus a promising therapeutic approach to the prevention and treatment of AD. Recently, we d...Amyloid-β （Aβ） protein aggregation is the main hallmark of Alzheimer＇s disease （AD）. Inhibition of Aft fibrillation is thus a promising therapeutic approach to the prevention and treatment of AD. Recently, we designed a heptapeptide inhibitor, LVFFARK （LK7）. LK7 shows a promising inhibitory capability on Aft fibrillation, but is prone to self-assembling and displays high cytotoxicity, which would hinder its practical application. Herein, we modified LK7 by a head-to-tail cyclization and obtained a cyclic LK7 （cLK7）. cLK7 exhibits a different self-assembly behavior from LK7, and has higher stability against proteolysis than LK7 and little cytotoxicity to SH-SY5Y cells. Thermodynamic analysis revealed that both LK7 and cLK7 could bind to Aβ40 by electrostatic interactions, hydrogen bonding and hydrophobic interactions, but the binding affinity of cLK7 for Afl40 （KD = 4.96 μmol/L） is six times higher than that of LK7 （KD = 32.2 μmol/L）. The strong binding enables cLK7 to stabilize the secondary structure of Aβ40 and potently inhibit its nucleation, fibrillation and cytotoxicity at extensive concentration range, whereas LK7 could only moderately inhibit Aβ40 fibrillation and cytotoxicity at low concentrations. The findings indicate that the peptide cyclization is a promising approach to enhance the performance of peptide-based amyloid inhibitors.展开更多
Background:Amyloid beta peptide(Aβ)is the main component of extraneuronal senile plaques typical of Alzheimer’s disease(AD)brains.Although Aβis produced by normal neurons,it is shown to accumulate in large amounts ...Background:Amyloid beta peptide(Aβ)is the main component of extraneuronal senile plaques typical of Alzheimer’s disease(AD)brains.Although Aβis produced by normal neurons,it is shown to accumulate in large amounts within neuronal lysosomes in AD.We have recently shown that under normal conditions the majority of Aβis localized extralysosomally,while oxidative stress significantly increases intralysosomal Aβcontent through activation of macroautophagy.It is also suggested that impaired Aβsecretion and resulting intraneuronal increase of Aβcan contribute to AD pathology.However,it is not clear how Aβis distributed inside normal neurons,and how this distribution is effected when Aβsecretion is inhibited.Methods:Using retinoic acid differentiated neuroblastoma cells and neonatal rat cortical neurons,we studied intracellular distribution of Aβby double immunofluorescence microscopy for Aβ40 or Aβ42 and different organelle markers.In addition,we analysed the effect of tetanus toxin-induced exocytosis inhibition on the intracellular distribution of Aβ.Results:Under normal conditions,Aβwas found in the small cytoplasmic granules in both neurites and perikarya.Only minor portion of Aβwas colocalized with trans-Golgi network,Golgi-derived vesicles,early and late endosomes,lysosomes,and synaptic vesicles,while the majority of Aβgranules were not colocalized with any of these structures.Furthermore,treatment of cells with tetanus toxin significantly increased the amount of intracellular Aβin both perikarya and neurites.Finally,we found that tetanus toxin increased the levels of intralysosomal Aβalthough the majority of Aβstill remained extralysosomally.Conclusion:Our results indicate that most Aβis not localized to Golgi-related structures,endosomes,lysosomes secretory vesicles or other organelles,while the suppression of Aβsecretion increases intracellular intra-and extralysosomal Aβ.展开更多
基金the Foundation of Shandong Educational Committee
文摘INTRODUCTION Peptic ulcer,as a common disease,seriouslyaffected people’s,work and life.Its occurrence,development and change have close relationshipwith the change of people’s moods.Animalexperiment proved that significant changes occurredin the endocrine system of the gastric ulcer rats.
文摘Aim: The abnormal accumulation, assembly and deposition of the amyloid β-protein (Aβ) are prominent pathological features of patients with Alzheimer’s disease (AD) and related disorders. A number of factors in the brain can influence Aβ accumulation and associated pathologies. The aim of the present study was to determine the consequences of deleting nitric oxide synthase (NOS) 3, the endothelial form of NOS, in Tg-5xFAD mice, a model of parenchymal AD-like amyloid pathology. Methods: Tg-5xFAD mice were bred with NOS3-/- mice. Cohorts of Tg-5xFAD mice and bigenic Tg-5xFAD/NOS3-/- mice were aged to six months followed by collection of the blood and brain tissues from the mice for biochemical and pathological analyses. Results: ELISA analyses show that the absence of NOS3 results in elevated levels of cerebral and plasma Aβ peptides in Tg-5xFAD mice. Immunohistochemical analyses show that the absence of NOS3 increased the amount of parenchymal Aβ deposition and fibrillar amyloid accumulation in Tg-5xFAD mice. The elevated levels of Aβ were not due to changes in the expression levels of transgene encoded human amyloid precursor protein (APP), endogenous β-secretase, or increased proteolytic processing of APP. Conclusions: The results from this study suggest that the loss of NOS3 activity enhances Aβ pathology in Tg-5xFAD mice. These findings are similar to previous studies of NOS2 deletion suggesting that reduced NOS activity and NO levels enhance amyloid-associated pathologies in human APP transgenic mice.
基金supported by the National 985 Project "linguistic science technology and the construction of interdisciplinary innovation platform in current society",No.985yk002the National 985 Project "cognitive and neural information science platform",No.904273258
文摘PC12 cell injury was induced using 20 μM amyloid β-protein 25-35 to establish a model of Alzheimer＇s disease. The cells were then treated with 5, 10, and 25 μM Schisandrin B. Methylthiazolyldiphenyl-tetrazolium bromide assays and Hoechst 33342 staining results showed that with increasing Schisandrin B concentration, the survival rate of PC12 cells injured by amyloid β-protein 25-35 gradually increased and the rate of apoptosis gradually decreased. Reverse transcription-PCR, immunocytochemical staining and western blot results showed that with increasing Schisandrin B concentration, the mRNA and protein expression of vacuolar protein sorting 35 and amyloid precursor protein were gradually decreased. Vacuolar protein sorting 35 and amyloid precursor protein showed a consistent trend for change. These findings suggest that 5, 10, and 25 μM Schisandrin B antagonizes the cellular injury induced by amyloid β-protein 25-35 in a dose-dependent manner. This may be caused by decreasing the expression of vacuolar protein sorting 35 and amyloid precursor protein.
基金funded by the National Natural Science Foundation of China (21908165 and 21878234)Regional Innovation System Project (21ZYQCSY00050)。
文摘Amyloid β-protein(Aβ) and Tau, two common pathogenic proteins associated with Alzheimer’s disease(AD), cross-interact, and thus co-assemble into hybrid aggregates. However, molecular mechanism of the cross-interactions remains unclear. To explore the issue, docking and molecular dynamics(MD) simulations were coupled to study the cross-interactions between Aβ pentamer and Tau pentamer. Four stable hybrid decamer conformations including double layer, single layer, block, and part-in were obtained by protein-protein docking software HADDOCK 2.2. Then, MD simulations were used to explore the molecular mechanism of cross-interactions between Aβ pentamer and Tau pentamer. The results of MD simulations showed that the part-in structure was the most stable among all the above four representative ones. The binding energy between Aβ and Tau was about-759.77 kJ·mol-1in the part-in structure. Moreover, the part-in conformation would undergo conformational transition, which would improve its hydrophobicity and make the structure more compact. This work offers a structural understanding of cross-interactions between Aβ and Tau linked to AD.
文摘目的:对阿尔茨海默病(Alzheimer s disease,AD)与血管性痴呆(vascular dementia,VD)血浆β-微管蛋白与淀粉样蛋白前体(APP)进行定量分析,分析这些指标的变化是否可以为临床诊断阿尔茨海默病提供生物学方面的帮助。方法:用蛋白免疫印迹法(Western-blot)测定11例AD、11例VD和8个正常老年人血浆β-微管蛋白和APP的水平。结果:(1)血浆APP含量AD患者(84.36±41.34)的高于VD患者(56.34±18.68)和正常人(43.25±27.67),P<0.05;(2)血浆中β-微管蛋白含量AD患者(105.91±41.25)高于VD患者(64.36±28.27)和正常人(52.25±11.11),P<0.05;(3)VD患者和正常人之间APP和β-微管蛋白比较无明显差异(P>0.05)。(4)Pear-son相关分析显示:血浆中APP和β-微管蛋白含量可能存在一定的相关性,相关系数为0.451(P<0.05)。结论:AD患者血浆APP和β-微管蛋白含量明显高于正常人和VD患者,对AD患者血浆APP和β-微管蛋白含量的测定对AD的诊断可能具有一定的意义。
文摘Amyloid-β （Aβ） protein aggregation is the main hallmark of Alzheimer＇s disease （AD）. Inhibition of Aft fibrillation is thus a promising therapeutic approach to the prevention and treatment of AD. Recently, we designed a heptapeptide inhibitor, LVFFARK （LK7）. LK7 shows a promising inhibitory capability on Aft fibrillation, but is prone to self-assembling and displays high cytotoxicity, which would hinder its practical application. Herein, we modified LK7 by a head-to-tail cyclization and obtained a cyclic LK7 （cLK7）. cLK7 exhibits a different self-assembly behavior from LK7, and has higher stability against proteolysis than LK7 and little cytotoxicity to SH-SY5Y cells. Thermodynamic analysis revealed that both LK7 and cLK7 could bind to Aβ40 by electrostatic interactions, hydrogen bonding and hydrophobic interactions, but the binding affinity of cLK7 for Afl40 （KD = 4.96 μmol/L） is six times higher than that of LK7 （KD = 32.2 μmol/L）. The strong binding enables cLK7 to stabilize the secondary structure of Aβ40 and potently inhibit its nucleation, fibrillation and cytotoxicity at extensive concentration range, whereas LK7 could only moderately inhibit Aβ40 fibrillation and cytotoxicity at low concentrations. The findings indicate that the peptide cyclization is a promising approach to enhance the performance of peptide-based amyloid inhibitors.
基金This work was supported by the Gustav V and Queen Victoria Foundation(JM),County Council of Ostergotland(JM,LZ,MH),Stiftelsen Olle Engkvist Byggmastare(LZ),Stiftelsen for Gamla Tjanarinnor(LZ,AC-M),Loo and Hans Ostermans foundation(LZ),Gun och Bertil Stohnes Stiftelse(LZ,AC-M),Lions Forskningsfond(LZ),Svenska Lundbeckstiftelsen(LZ),Karolinska Institute Fund for Geriatric Research(AC-M),Alice och Knut Wallenberg Stiftelse(AC-M),Swedish Alzheimer Foundation(MH)and The Swedish Brain Power(AC-M).
文摘Background:Amyloid beta peptide(Aβ)is the main component of extraneuronal senile plaques typical of Alzheimer’s disease(AD)brains.Although Aβis produced by normal neurons,it is shown to accumulate in large amounts within neuronal lysosomes in AD.We have recently shown that under normal conditions the majority of Aβis localized extralysosomally,while oxidative stress significantly increases intralysosomal Aβcontent through activation of macroautophagy.It is also suggested that impaired Aβsecretion and resulting intraneuronal increase of Aβcan contribute to AD pathology.However,it is not clear how Aβis distributed inside normal neurons,and how this distribution is effected when Aβsecretion is inhibited.Methods:Using retinoic acid differentiated neuroblastoma cells and neonatal rat cortical neurons,we studied intracellular distribution of Aβby double immunofluorescence microscopy for Aβ40 or Aβ42 and different organelle markers.In addition,we analysed the effect of tetanus toxin-induced exocytosis inhibition on the intracellular distribution of Aβ.Results:Under normal conditions,Aβwas found in the small cytoplasmic granules in both neurites and perikarya.Only minor portion of Aβwas colocalized with trans-Golgi network,Golgi-derived vesicles,early and late endosomes,lysosomes,and synaptic vesicles,while the majority of Aβgranules were not colocalized with any of these structures.Furthermore,treatment of cells with tetanus toxin significantly increased the amount of intracellular Aβin both perikarya and neurites.Finally,we found that tetanus toxin increased the levels of intralysosomal Aβalthough the majority of Aβstill remained extralysosomally.Conclusion:Our results indicate that most Aβis not localized to Golgi-related structures,endosomes,lysosomes secretory vesicles or other organelles,while the suppression of Aβsecretion increases intracellular intra-and extralysosomal Aβ.
