BACKGROUND： Previous studies have demonstrated that Piper futokadsura stem selectively inhibits expression of amyloid precursor protein （APP） at the mRNA level. In addition, the piperlonguminine （A） and dihydropi...BACKGROUND： Previous studies have demonstrated that Piper futokadsura stem selectively inhibits expression of amyloid precursor protein （APP） at the mRNA level. In addition, the piperlonguminine （A） and dihydropiperlonguminine （B） components （1 ： 0.8）, which can be separated from Futokadsura stem, selectively inhibit expression of the APP at mRNA and protein levels. OBJECTIVE： Based on previous findings, the present study investigated the effects of β-site amyloid precursor protein cleaving enzyme （BACE1） and APP genes on the production of β-amyloid peptide 42 （Aβ42） in human neuroblastoma cells （SK-N-SH cells） using small interfering RNAs （siRNAs） and A/B components separated from Futokadsura stem, respectively. DESIGN, TIME AND SETTING： A gene interference-based randomized, controlled, in vitro experiment was performed at the Key Laboratory of Cardiovascular Remodeling and Function Research, Ministries of Education and Public Health, and Institute of Pharmacologic Research, School of Pharmaceutical Science ＆ Department of Biochemistry, School of Medicine, Shandong University between July 2006 and December 2007. MATERIALS： SK-N-SH cells were provided by Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai, China; mouse anti-human BACE1 monoclonal antibody was purchased from R＆D Systems, USA; mouse anti-human APP monoclonal antibody was purchased from Cell Signaling Technology, USA; and horseradish peroxidase （HRP）-conjugated goat anti-mouse IgG was provided by Sigma, USA. METHODS： The human BACE1 cDNA sequence was obtained from NCBI website （www.ncbi.nlm.nih.gov/sites/entrez）. Three pairs of siRNAs, specific to human BACE1 gene, were synthesized through the use of Silencer pre-designed siRNA specification, and were transfected into SK-N-SH cells with siPORT NeoFX transfection agent to compare the effects of different concentrations of siRNAs （10-50 nmol/L） on SK-N-SH cells. Futokadsura stem was separated and purified with chemical methods, and the crystal was composed of A/B components, with an A to B ratio of 1：0.8. The A/B （1 ： 0.8） components were added to the SK-N-SH cells at different concentrations （13.13, 6.56, and 3.28 mg/mL）. MAIN OUTCOME MEASURES： Using RT-PCR and Western blot methods, BACE1 and APP expression at mRNA and protein levels was detected in SK-N-SH cells following treatment with different siRNAs and concentrations of Futokadsura stem-separated A/B components, respectively. Altered Aβ42 secretion by SK-N-SH cells was determined by ELISA. RESULTS： BACE1 mRNA and protein levels were significantly suppressed by 40 and 50 nmol/L siRNAs at 48 hours post-transfection. A/B components （1 ： 0.8）, which were separated from Futokadsura stem, selectively inhibited mRNA and protein expression of APP in SK-N-SH cells. Aβ42 secretion by SK-N-SH cells was significantly decreased following treatment with siRNAs or A/B components. CONCLUSION： Inhibition of BACE1 and APP genes by various materials and methods efficiently decreased production of Aβ42.展开更多
In patients with Alzheimer’s disease,gamma-glutamyl transferase 5(GGT5)expression has been observed to be downregulated in cerebrovascular endothelial cells.However,the functional role of GGT5 in the development of A...In patients with Alzheimer’s disease,gamma-glutamyl transferase 5(GGT5)expression has been observed to be downregulated in cerebrovascular endothelial cells.However,the functional role of GGT5 in the development of Alzheimer’s disease remains unclear.This study aimed to explore the effect of GGT5 on cognitive function and brain pathology in an APP/PS1 mouse model of Alzheimer’s disease,as well as the underlying mechanism.We observed a significant reduction in GGT5 expression in two in vitro models of Alzheimer’s disease(Aβ_(1-42)-treated hCMEC/D3 and bEnd.3 cells),as well as in the APP/PS1 mouse model.Additionally,injection of APP/PS1 mice with an adeno-associated virus encoding GGT5 enhanced hippocampal synaptic plasticity and mitigated cognitive deficits.Interestingly,increasing GGT5 expression in cerebrovascular endothelial cells reduced levels of both soluble and insoluble amyloid-βin the brains of APP/PS1 mice.This effect may be attributable to inhibition of the expression ofβ-site APP cleaving enzyme 1,which is mediated by nuclear factor-kappa B.Our findings demonstrate that GGT5 expression in cerebrovascular endothelial cells is inversely associated with Alzheimer’s disease pathogenesis,and that GGT5 upregulation mitigates cognitive deficits in APP/PS1 mice.These findings suggest that GGT5 expression in cerebrovascular endothelial cells is a potential therapeutic target and biomarker for Alzheimer’s disease.展开更多
Our previous findings have demonstrated that autophagy regulation can alleviate the decline of learning and memory by eliminating deposition of extracellular beta-amyloid peptide （Aβ） in the brain after stroke, but...Our previous findings have demonstrated that autophagy regulation can alleviate the decline of learning and memory by eliminating deposition of extracellular beta-amyloid peptide （Aβ） in the brain after stroke, but the exact mechanism is unclear. It is presumed that the regulation of beta-site APP-deaving enzyme 1 （BACE1）, the rate-limiting enzyme in metabolism of Aβ, would be a key site. Neuro-2a/amyloid precursor protein 695 （APP695） cell models of cerebral isch- emia were established by oxygen-glucose deprivation to investigate the effects of Rapamycin （an autophagy inducer） or 3-methyladenine （an autophagy inhibitor） on the expression of BACE1. Either oxygen-glucose deprivation or Rapamycin down-regulated the expression of BACE1 while 3-methyladenine up-regulated BACE1 expression. These results confirm that oxygen-glucose deprivation down-regulates BACE1 expression in Neuro-2a/APP695 cells through the introduction of autophagy.展开更多
Several studies have demonstrated that the amount of beta-amyloid （Aβ） protein in the brain can be lowered by down-regulating Aβ production, promoting Aβ degradation, reducing Aβ oligomerization or deposition, ...Several studies have demonstrated that the amount of beta-amyloid （Aβ） protein in the brain can be lowered by down-regulating Aβ production, promoting Aβ degradation, reducing Aβ oligomerization or deposition, thereby alleviating symptoms of Alzheimer＇s disease. Curcumin has been known to be a peroxisome proliferator activated receptor gamma （PPARy） agonist and can obviously inhibit Aβ production and oligomerization. This study investigated the effects of curcumin on the G-site APP cleaving enzyme 1 （BACE1） activity and PPARy expression in human neuroblastoma SH-SY5Y cells, and validated the inhibitory effects of curcumin on Aβ40/42 expression in the brain. Results revealed that PPARy mRNA and protein expression in the human neuroblastoma SH-SY5Y cells significantly increased with increasing curcumin concentration and time course （P 〈 0.05）; BACE1 mRNA and protein expression and Aβ40/42 production significantly decreased with increasing curcumin concentration and time course （P 〈 0.05）. The changes in PPARy and BACE1 expression during Aβ production could be reversed by the PPARy antagonist GW9662. These findings indicate that curcumin reduced Aβ production by activating PPARy expression and inhibiting BACE1 expression in a concentration- and time-dependent manner.展开更多
Objective To generate eukaryotic expression vector of siRNA specific for β-site APP cleaving enzyme(BACE),and detect the interfering effect to the expression of BACE. Methods To clone the BACE targeting siRNA gene by...Objective To generate eukaryotic expression vector of siRNA specific for β-site APP cleaving enzyme(BACE),and detect the interfering effect to the expression of BACE. Methods To clone the BACE targeting siRNA gene by PCR, the PCR products was inserted into the pUC19/EGFP-U6 plasmid. Then it was sub-cloned into the vector named pLXSN. The resultant plasmid was named pLXSN/EGFP-U6-siBACE, it was packaged into AmphoPack-293 cells by calcium phosphate transfection and collected the virus supernatant. The neuroblastoma cells SK-N-SH was infected with the pLXSN/EGFP-U6-siBACE retroviral vector, immunohistochemistry method was used to detect whether the pLXSN/EGFP-U6-siBACE infection can inhibit the expression of BACE of the neuroblastoma cells. Results The pLXSN/EGFP-U6-siBACE retroviral vector was constructed successfully and the siBACE can inhibit the BACE of the neuroblastma effectively. Conclusion The siRNA can inhibit the expression of the BACE gene, the endogenous production of BACE protein was decreased. It will lay the important foundation for using RNA technology to prevent the Alzheimer's disease.展开更多
基金the National Natural Science Foundation of China,No. NSFC-3027164
文摘BACKGROUND： Previous studies have demonstrated that Piper futokadsura stem selectively inhibits expression of amyloid precursor protein （APP） at the mRNA level. In addition, the piperlonguminine （A） and dihydropiperlonguminine （B） components （1 ： 0.8）, which can be separated from Futokadsura stem, selectively inhibit expression of the APP at mRNA and protein levels. OBJECTIVE： Based on previous findings, the present study investigated the effects of β-site amyloid precursor protein cleaving enzyme （BACE1） and APP genes on the production of β-amyloid peptide 42 （Aβ42） in human neuroblastoma cells （SK-N-SH cells） using small interfering RNAs （siRNAs） and A/B components separated from Futokadsura stem, respectively. DESIGN, TIME AND SETTING： A gene interference-based randomized, controlled, in vitro experiment was performed at the Key Laboratory of Cardiovascular Remodeling and Function Research, Ministries of Education and Public Health, and Institute of Pharmacologic Research, School of Pharmaceutical Science ＆ Department of Biochemistry, School of Medicine, Shandong University between July 2006 and December 2007. MATERIALS： SK-N-SH cells were provided by Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai, China; mouse anti-human BACE1 monoclonal antibody was purchased from R＆D Systems, USA; mouse anti-human APP monoclonal antibody was purchased from Cell Signaling Technology, USA; and horseradish peroxidase （HRP）-conjugated goat anti-mouse IgG was provided by Sigma, USA. METHODS： The human BACE1 cDNA sequence was obtained from NCBI website （www.ncbi.nlm.nih.gov/sites/entrez）. Three pairs of siRNAs, specific to human BACE1 gene, were synthesized through the use of Silencer pre-designed siRNA specification, and were transfected into SK-N-SH cells with siPORT NeoFX transfection agent to compare the effects of different concentrations of siRNAs （10-50 nmol/L） on SK-N-SH cells. Futokadsura stem was separated and purified with chemical methods, and the crystal was composed of A/B components, with an A to B ratio of 1：0.8. The A/B （1 ： 0.8） components were added to the SK-N-SH cells at different concentrations （13.13, 6.56, and 3.28 mg/mL）. MAIN OUTCOME MEASURES： Using RT-PCR and Western blot methods, BACE1 and APP expression at mRNA and protein levels was detected in SK-N-SH cells following treatment with different siRNAs and concentrations of Futokadsura stem-separated A/B components, respectively. Altered Aβ42 secretion by SK-N-SH cells was determined by ELISA. RESULTS： BACE1 mRNA and protein levels were significantly suppressed by 40 and 50 nmol/L siRNAs at 48 hours post-transfection. A/B components （1 ： 0.8）, which were separated from Futokadsura stem, selectively inhibited mRNA and protein expression of APP in SK-N-SH cells. Aβ42 secretion by SK-N-SH cells was significantly decreased following treatment with siRNAs or A/B components. CONCLUSION： Inhibition of BACE1 and APP genes by various materials and methods efficiently decreased production of Aβ42.
基金supported by STI2030-Major Projects,No.2021ZD 0201801(to JG)Shanxi Province Basic Research Program,No.20210302123429(to QS).
文摘In patients with Alzheimer’s disease,gamma-glutamyl transferase 5(GGT5)expression has been observed to be downregulated in cerebrovascular endothelial cells.However,the functional role of GGT5 in the development of Alzheimer’s disease remains unclear.This study aimed to explore the effect of GGT5 on cognitive function and brain pathology in an APP/PS1 mouse model of Alzheimer’s disease,as well as the underlying mechanism.We observed a significant reduction in GGT5 expression in two in vitro models of Alzheimer’s disease(Aβ_(1-42)-treated hCMEC/D3 and bEnd.3 cells),as well as in the APP/PS1 mouse model.Additionally,injection of APP/PS1 mice with an adeno-associated virus encoding GGT5 enhanced hippocampal synaptic plasticity and mitigated cognitive deficits.Interestingly,increasing GGT5 expression in cerebrovascular endothelial cells reduced levels of both soluble and insoluble amyloid-βin the brains of APP/PS1 mice.This effect may be attributable to inhibition of the expression ofβ-site APP cleaving enzyme 1,which is mediated by nuclear factor-kappa B.Our findings demonstrate that GGT5 expression in cerebrovascular endothelial cells is inversely associated with Alzheimer’s disease pathogenesis,and that GGT5 upregulation mitigates cognitive deficits in APP/PS1 mice.These findings suggest that GGT5 expression in cerebrovascular endothelial cells is a potential therapeutic target and biomarker for Alzheimer’s disease.
基金supported by the National Natural Science Foundation of China,No.31171014,31371065a grant from Shanghai Municipal Health Bureau,China,No.20134125a grant from Shanghai Pudong District Health Bureau of China,No.PDZz2013-10
文摘Our previous findings have demonstrated that autophagy regulation can alleviate the decline of learning and memory by eliminating deposition of extracellular beta-amyloid peptide （Aβ） in the brain after stroke, but the exact mechanism is unclear. It is presumed that the regulation of beta-site APP-deaving enzyme 1 （BACE1）, the rate-limiting enzyme in metabolism of Aβ, would be a key site. Neuro-2a/amyloid precursor protein 695 （APP695） cell models of cerebral isch- emia were established by oxygen-glucose deprivation to investigate the effects of Rapamycin （an autophagy inducer） or 3-methyladenine （an autophagy inhibitor） on the expression of BACE1. Either oxygen-glucose deprivation or Rapamycin down-regulated the expression of BACE1 while 3-methyladenine up-regulated BACE1 expression. These results confirm that oxygen-glucose deprivation down-regulates BACE1 expression in Neuro-2a/APP695 cells through the introduction of autophagy.
基金the National Natural Science Foundation of China,No.30600196the Science Foundation of Chongqing,No.2006BB5042the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,No.[2007]1108
文摘Several studies have demonstrated that the amount of beta-amyloid （Aβ） protein in the brain can be lowered by down-regulating Aβ production, promoting Aβ degradation, reducing Aβ oligomerization or deposition, thereby alleviating symptoms of Alzheimer＇s disease. Curcumin has been known to be a peroxisome proliferator activated receptor gamma （PPARy） agonist and can obviously inhibit Aβ production and oligomerization. This study investigated the effects of curcumin on the G-site APP cleaving enzyme 1 （BACE1） activity and PPARy expression in human neuroblastoma SH-SY5Y cells, and validated the inhibitory effects of curcumin on Aβ40/42 expression in the brain. Results revealed that PPARy mRNA and protein expression in the human neuroblastoma SH-SY5Y cells significantly increased with increasing curcumin concentration and time course （P 〈 0.05）; BACE1 mRNA and protein expression and Aβ40/42 production significantly decreased with increasing curcumin concentration and time course （P 〈 0.05）. The changes in PPARy and BACE1 expression during Aβ production could be reversed by the PPARy antagonist GW9662. These findings indicate that curcumin reduced Aβ production by activating PPARy expression and inhibiting BACE1 expression in a concentration- and time-dependent manner.
文摘Objective To generate eukaryotic expression vector of siRNA specific for β-site APP cleaving enzyme(BACE),and detect the interfering effect to the expression of BACE. Methods To clone the BACE targeting siRNA gene by PCR, the PCR products was inserted into the pUC19/EGFP-U6 plasmid. Then it was sub-cloned into the vector named pLXSN. The resultant plasmid was named pLXSN/EGFP-U6-siBACE, it was packaged into AmphoPack-293 cells by calcium phosphate transfection and collected the virus supernatant. The neuroblastoma cells SK-N-SH was infected with the pLXSN/EGFP-U6-siBACE retroviral vector, immunohistochemistry method was used to detect whether the pLXSN/EGFP-U6-siBACE infection can inhibit the expression of BACE of the neuroblastoma cells. Results The pLXSN/EGFP-U6-siBACE retroviral vector was constructed successfully and the siBACE can inhibit the BACE of the neuroblastma effectively. Conclusion The siRNA can inhibit the expression of the BACE gene, the endogenous production of BACE protein was decreased. It will lay the important foundation for using RNA technology to prevent the Alzheimer's disease.
