Tau oligomers are the etiologic molecules of Alzheimer disease(AD), and correlate strongly with neuronal loss and exhibit neurotoxicity. Recent evidence indicates that small tau oligomers are the most relevant toxic a...Tau oligomers are the etiologic molecules of Alzheimer disease(AD), and correlate strongly with neuronal loss and exhibit neurotoxicity. Recent evidence indicates that small tau oligomers are the most relevant toxic aggregate species. The aim of the present study was to investigate the mechanisms of cornel iridoid glycoside(CIG) on tau oligomers and cognitive functions. We injected wortmannin and GF-109203 X(WM/GFX, 200 μmol·L-1 each) into the lateral ventricles to induce tau oligomer and memory impairment in rats. When oral y administered with CIG at 60 and 120 mg·kg-1 per day for 14 d, CIG decreased the escape latency in Morris water maze test. We also found that CIG restored the expression of presynaptic p-synapsin, synaptophysin, and postsynaptic density-95(PSD-95) decreased by WM/GFX in rat cortex. CIG reduced the accumulation of tau oligomers in the brain of WM/GFX rats and in cells transfected with wild type glycogen synthase kinase-3β(wt GSK-3β). In addition, CIG up-regulated the levels of ATG7, ATG12, Beclin-1, and LC3 II in vivo and in vitro, suggesting the restoration of autophagy function. These results suggest that CIG could ameliorate memory deficits and regulate memory-associated synaptic proteins through the clearance of tau oligomers accumulation. Moreover, CIG clears tau oligomers by restoring autophagy function.展开更多
Onion （Allium cepa L.） was an economic vegetable and a strictly biennial herb, which was widely distributed in the world. In the past, it was a strictly biennial plant, the studies had shown that FT （FLOWERING LOCU...Onion （Allium cepa L.） was an economic vegetable and a strictly biennial herb, which was widely distributed in the world. In the past, it was a strictly biennial plant, the studies had shown that FT （FLOWERING LOCUS T） gene was involved in the photoperiod pathway to regulate fowering in the model plant. In this study, transcriptome sequencing method was used to obtain cDNA sequence of FT homologous gene in onion, named AcFT3 （KF864665）. AcFT3 had a full-length of 540 bp, encoded 179 amino acids, with 98.31% homology to AfFT （Allium fstulosum）, and 63.0%-84.0% homology to other higher plants. Phylogenetic tree analysis indicated that AcFT3 had the closest relationship with AfFT. The results of quantitative RT-PCR showed the expression pattern of AcFT3 both in vegetative growth of onion and in different organs of bolting and fowering, the expression level of AcFT3 reached the highest in the leaves before bolting and in the fower organs after bolting.展开更多
OBJECTIVE PP2Ac demethyl⁃ation is regulated by LCMT(a specific leucine carboxyl methyltransferase catalyzing methyla⁃tion of PP2A)and PME(a specific methylester⁃ase catalyzing demethylation of PP2A.This study was to i...OBJECTIVE PP2Ac demethyl⁃ation is regulated by LCMT(a specific leucine carboxyl methyltransferase catalyzing methyla⁃tion of PP2A)and PME(a specific methylester⁃ase catalyzing demethylation of PP2A.This study was to investigate the mechanism of Cor⁃nel iridoid glycoside(CIG)on PP2A catalytic sub⁃unit C(PP2Ac).METHODS Recombined lentivi⁃rus vector was used to deliver PME-1 genetic materials into N2a cells or transfected LCMT-1 siRNA into N2a cells to block the expression of LCMT-1.Twenty-four hours later,cells were rinsed twice with cold PBS(pH 7.4)and CIG at different concentrations(50,100 and 200 g·L^(-1),respectively)were added for 24 h.Western blotting was used to PP2Ac,demethylaion/methylation PP2Ac,LCMT-1 and PME-1.The ac⁃tivity of PP2A was detected by a biochemical as⁃say.RESULTS①Lentivirus transferred PME-1 was expressed at high level in the N2a cells after transduction.Correspondingly,the demethylation of PP2Ac was increasing and PP2A activity was decreasing after transduction.Treatment with CIG for 24 h reversed the increase of PME-1 and demethylation of PP2Ac without influencing LCMT-1 expression.PP2A activity was also sig⁃nificantly enhanced in CIG treatment group,compared with the cells after PME-1 transduc⁃tion.②LCMT-1 siRNA significantly decreased LCMT-1 expression.CIG did not affect LCMT-1expression.however,demethylation of PP2Ac is increased in siRNA-transfected cells and CIG could reversed the high demethylation of PP2Ac and PP2A activity.CONLUSION CIG increases methylation of PP2A subunit C by inhibiting PME-1.展开更多
文摘Tau oligomers are the etiologic molecules of Alzheimer disease(AD), and correlate strongly with neuronal loss and exhibit neurotoxicity. Recent evidence indicates that small tau oligomers are the most relevant toxic aggregate species. The aim of the present study was to investigate the mechanisms of cornel iridoid glycoside(CIG) on tau oligomers and cognitive functions. We injected wortmannin and GF-109203 X(WM/GFX, 200 μmol·L-1 each) into the lateral ventricles to induce tau oligomer and memory impairment in rats. When oral y administered with CIG at 60 and 120 mg·kg-1 per day for 14 d, CIG decreased the escape latency in Morris water maze test. We also found that CIG restored the expression of presynaptic p-synapsin, synaptophysin, and postsynaptic density-95(PSD-95) decreased by WM/GFX in rat cortex. CIG reduced the accumulation of tau oligomers in the brain of WM/GFX rats and in cells transfected with wild type glycogen synthase kinase-3β(wt GSK-3β). In addition, CIG up-regulated the levels of ATG7, ATG12, Beclin-1, and LC3 II in vivo and in vitro, suggesting the restoration of autophagy function. These results suggest that CIG could ameliorate memory deficits and regulate memory-associated synaptic proteins through the clearance of tau oligomers accumulation. Moreover, CIG clears tau oligomers by restoring autophagy function.
基金Supported by Fund Project of Heilongjiang Province(C2015017)Heilongjiang Provincial Science and Technology Commissioner Project(GC13B09)
文摘Onion （Allium cepa L.） was an economic vegetable and a strictly biennial herb, which was widely distributed in the world. In the past, it was a strictly biennial plant, the studies had shown that FT （FLOWERING LOCUS T） gene was involved in the photoperiod pathway to regulate fowering in the model plant. In this study, transcriptome sequencing method was used to obtain cDNA sequence of FT homologous gene in onion, named AcFT3 （KF864665）. AcFT3 had a full-length of 540 bp, encoded 179 amino acids, with 98.31% homology to AfFT （Allium fstulosum）, and 63.0%-84.0% homology to other higher plants. Phylogenetic tree analysis indicated that AcFT3 had the closest relationship with AfFT. The results of quantitative RT-PCR showed the expression pattern of AcFT3 both in vegetative growth of onion and in different organs of bolting and fowering, the expression level of AcFT3 reached the highest in the leaves before bolting and in the fower organs after bolting.
文摘OBJECTIVE PP2Ac demethyl⁃ation is regulated by LCMT(a specific leucine carboxyl methyltransferase catalyzing methyla⁃tion of PP2A)and PME(a specific methylester⁃ase catalyzing demethylation of PP2A.This study was to investigate the mechanism of Cor⁃nel iridoid glycoside(CIG)on PP2A catalytic sub⁃unit C(PP2Ac).METHODS Recombined lentivi⁃rus vector was used to deliver PME-1 genetic materials into N2a cells or transfected LCMT-1 siRNA into N2a cells to block the expression of LCMT-1.Twenty-four hours later,cells were rinsed twice with cold PBS(pH 7.4)and CIG at different concentrations(50,100 and 200 g·L^(-1),respectively)were added for 24 h.Western blotting was used to PP2Ac,demethylaion/methylation PP2Ac,LCMT-1 and PME-1.The ac⁃tivity of PP2A was detected by a biochemical as⁃say.RESULTS①Lentivirus transferred PME-1 was expressed at high level in the N2a cells after transduction.Correspondingly,the demethylation of PP2Ac was increasing and PP2A activity was decreasing after transduction.Treatment with CIG for 24 h reversed the increase of PME-1 and demethylation of PP2Ac without influencing LCMT-1 expression.PP2A activity was also sig⁃nificantly enhanced in CIG treatment group,compared with the cells after PME-1 transduc⁃tion.②LCMT-1 siRNA significantly decreased LCMT-1 expression.CIG did not affect LCMT-1expression.however,demethylation of PP2Ac is increased in siRNA-transfected cells and CIG could reversed the high demethylation of PP2Ac and PP2A activity.CONLUSION CIG increases methylation of PP2A subunit C by inhibiting PME-1.
