Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's dis...Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's disease-related dementia.Our previous study identified the upregulation of microRNA-502-3p(miR-502-3p)and downregulation of GABA type A receptor subunitα-1 in Alzheimer's disease synapses.This study investigated a new molecular relationship between miR-502-3p and GABAergic synapse function.In vitro studies were perfo rmed using the mouse hippocampal neuronal cell line HT22 and miR-502-3p agomiRs and antagomiRs.In silico analysis identified multiple binding sites of miR-502-3p at GABA type A receptor subunitα-1 mRNA.Luciferase assay confirmed that miR-502-3p targets the GABA type A receptor subunitα-1 gene and suppresses the luciferase activity.Furthermore,quantitative reve rse transcription-polymerase chain reaction,miRNA in situ hybridization,immunoblotting,and immunostaining analysis confirmed that overexpression of miR-502-3p reduced the GABA type A receptor subunitα-1 level,while suppression of miR-502-3p increased the level of GABA type A receptor subunitα-1 protein.Notably,as a result of the overexpression of miR-502-3p,cell viability was found to be reduced,and the population of necrotic cells was found to be increased.The whole cell patch-clamp analysis of human-GABA receptor A-α1/β3/γ2L human embryonic kidney(HEK)recombinant cell line also showed that overexpression of miR-502-3p reduced the GABA current and overall GABA function,suggesting a negative correlation between miR-502-3p levels and GABAergic synapse function.Additionally,the levels of proteins associated with Alzheimer s disease were high with miR-502-3p overexpression and reduced with miR-502-3p suppression.The present study provides insight into the molecular mechanism of regulation of GABAergic synapses by miR-502-3p.We propose that micro-RNA,in particular miR-502-3p,could be a potential therapeutic to rget to modulate GABAergic synapse function in neurological disorders,including Alzheimer's disease and Alzheimer's diseaserelated dementia.展开更多
目的探讨威灵仙总皂苷通过调控微小RNA(miRNA)-410-3p对胶质瘤细胞生物学活性的影响以及对第10号染色体缺失的磷酸酶和张力蛋白同源物基因/蛋白激酶B/哺乳动物雷帕霉素靶蛋白(phosphatase and tensin homolog deleted on chromosome ten...目的探讨威灵仙总皂苷通过调控微小RNA(miRNA)-410-3p对胶质瘤细胞生物学活性的影响以及对第10号染色体缺失的磷酸酶和张力蛋白同源物基因/蛋白激酶B/哺乳动物雷帕霉素靶蛋白(phosphatase and tensin homolog deleted on chromosome ten/protein kinase B/mammalian target of rapamycin,PTEN/Akt/mTOR)信号通路的调节作用。方法用不同浓度威灵仙总皂苷处理U87细胞后,用CCK-8法检测细胞存活率。将对数生长期U87细胞随机分为对照组、NC组(转染miR-410-3p NC)、inhibitor组(转染miR-410-3p inhibitor)以及inhibitor联合威灵仙总皂苷组(转染miR-410-3p inhibitor 24 h后,40μmol·L^(-1)威灵仙总皂苷处理),依次检测miR-410-3p表达水平、细胞存活率、细胞迁移和侵袭力,miR-410-3p与PTEN的靶向关系和PTEN、p-Akt、Akt、p-mTOR以及mTOR蛋白的相对表达量。结果细胞存活率随威灵仙总皂苷浓度的升高而降低(P<0.05);与NC组比较,inhibitor组划痕愈合率、侵袭细胞数量、p-Akt和p-mTOR蛋白的相对表达量升高,miR-410-3p表达水平以及PTEN蛋白的相对表达量降低(P<0.05);与inhibitor组比较,inhibitor联合威灵仙总皂苷组细胞存活率、划痕愈合率、侵袭细胞数量、p-Akt和p-mTOR蛋白相对表达量降低,miR-410-3p表达水平以及PTEN蛋白相对表达量升高(P<0.05)。结论威灵仙总皂苷可抑制胶质瘤细胞的恶性生物学行为,其可能是通过上调miR-410-3p表达,进而调控PTEN/Akt/mTOR信号通路发挥作用。展开更多
基金supported by the National Institute on Aging (NIA)National Institutes of Health (NIH)+3 种基金Nos.K99AG065645,R00AG065645R00AG065645-04S1 (to SK)NIH research grants,NINDS,No.R01 NS115834NINDS/NIA,No.R01 NS115834-02S1 (to LG)。
文摘Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's disease-related dementia.Our previous study identified the upregulation of microRNA-502-3p(miR-502-3p)and downregulation of GABA type A receptor subunitα-1 in Alzheimer's disease synapses.This study investigated a new molecular relationship between miR-502-3p and GABAergic synapse function.In vitro studies were perfo rmed using the mouse hippocampal neuronal cell line HT22 and miR-502-3p agomiRs and antagomiRs.In silico analysis identified multiple binding sites of miR-502-3p at GABA type A receptor subunitα-1 mRNA.Luciferase assay confirmed that miR-502-3p targets the GABA type A receptor subunitα-1 gene and suppresses the luciferase activity.Furthermore,quantitative reve rse transcription-polymerase chain reaction,miRNA in situ hybridization,immunoblotting,and immunostaining analysis confirmed that overexpression of miR-502-3p reduced the GABA type A receptor subunitα-1 level,while suppression of miR-502-3p increased the level of GABA type A receptor subunitα-1 protein.Notably,as a result of the overexpression of miR-502-3p,cell viability was found to be reduced,and the population of necrotic cells was found to be increased.The whole cell patch-clamp analysis of human-GABA receptor A-α1/β3/γ2L human embryonic kidney(HEK)recombinant cell line also showed that overexpression of miR-502-3p reduced the GABA current and overall GABA function,suggesting a negative correlation between miR-502-3p levels and GABAergic synapse function.Additionally,the levels of proteins associated with Alzheimer s disease were high with miR-502-3p overexpression and reduced with miR-502-3p suppression.The present study provides insight into the molecular mechanism of regulation of GABAergic synapses by miR-502-3p.We propose that micro-RNA,in particular miR-502-3p,could be a potential therapeutic to rget to modulate GABAergic synapse function in neurological disorders,including Alzheimer's disease and Alzheimer's diseaserelated dementia.
