目的:观察apelin-13是否通过影响ABCA1蛋白水平从而调节Aβ代谢。方法:1Western blot检测PC-12细胞血管紧张素受体AT1相关的受体蛋白(putative recep tor p rotein related to the angiotensin recep tor AT1,APJ)表达,以确定PC-12细胞...
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目的:观察apelin-13是否通过影响ABCA1蛋白水平从而调节Aβ代谢。方法:1Western blot检测PC-12细胞血管紧张素受体AT1相关的受体蛋白(putative recep tor p rotein related to the angiotensin recep tor AT1,APJ)表达,以确定PC-12细胞存在apelin-13作用受体。2用不同浓度(1、10、100nmol/L)的apelin-13处理PC-12细胞24h及用100nmol/L apelin-13处理细胞24不同时间(12h、24h、48h)后,酶联免疫吸附法(ELISA)检测Aβ1-40及Aβ1-42水平,Western blot免疫印迹法检测APP、BACE1及NEP蛋白水平,根据试剂盒方法检测BACE1及NEP酶活性,RT-PCR检测ABCA1 m RNA水平,Western Blot检测ABCA1蛋白水平,液体闪烁计数法检测细胞内胆固醇的流出。3先使用ABCA1 Si RNA抑制PC-12细胞ABCA1蛋白表达,再使用100nmol/L apelin-13处理PC-12细胞24h,ELISA检测Aβ1-40及Aβ1-42水平,根据试剂盒方法检测BACE1及NEP酶活性。以确定ABCA1在apelin-13对PC-12细胞Aβ代谢影响中所起的作用。结果:1PC-12细胞存在APJ表达。2Apelin-13显著降低PC-12细胞Aβ1-40及Aβ1-42水平,对APP、BACE1及NEP蛋白表达无显著影响,降低BACE1酶活性,增加NEP酶活性,对ABCA1m RNA水平无影响,增加ABCA1蛋白水平,促进胆固醇流出,减少细胞内脂质蓄积。3使用ABCA1 Si RNA抑制PC-12细胞ABCA1蛋白表达后,apelin-13降低PC-12细胞Aβ1-40及Aβ1-42水平的作用显著减弱,其降低BACE1酶活性及增加NEP酶活性的作用显著抑制。结论:Apelin-13通过增加PC-12细胞ABCA1蛋白水平,从而减少Aβ水平。
Hematopoietic stem cells(HSCs)are a population of multipotent cells that can self-renew and differentiate into all blood *** development must be tightly controlled from cell fate determination to self-maintenance duri...
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Hematopoietic stem cells(HSCs)are a population of multipotent cells that can self-renew and differentiate into all blood *** development must be tightly controlled from cell fate determination to self-maintenance during *** involves a panel of important developmental signaling pathways and other factors which act synergistically within the HSC population and/or in the HSC *** conserved processes of HSC development plus many other developmental advantages make the zebrafish an ideal model organism to elucidate the regulatory mechanisms underlying HSC programming in vertebrates.I will talk about our recent progress on zebrafish HSCs using functional genomics approaches,with particular focus on how developmental signaling controls hemogenic endothelium-derived HSC *** hematopoietic stem cell system is a paradigm for stem cell *** of the zebrafish model to study signaling regulation of HSCs in vivo has resulted in a great deal of information concerning HSC biology in *** new findings facilitate a better understanding of molecular mechanisms of HSC programming,and will provide possible new strategies for generation and/or expansion of transplantable and functional HSCs in vitro.
抗心律失常药物的主要作用靶点是对心肌动作电位的形成有重要贡献的离子通道。心肌内向整流钾通道(IK1通道)是维持和稳定心肌静息电位的最重要的离子通道,也参与动作电位的形成。因此干预IK1通道对心肌的兴奋性和心律失常的发生将产生重要的作用。但是目前还没有用于临床的主要以IK1通道为靶点的药物。我们课题组前期的研究发现zacopride可以选择性激动IK1通道电流,并观察了激动IK1通道的抗心律失常和抗心室重构的作用,得到了非常令人兴奋的结果。***通过选择性激动IK1电流起到抗心律失常的作用:1)Zacopride可特异性激动大鼠心肌细胞IK1电流,对INa、ICa-L、Ito、IKsus、IKr、和INa/Ca无显著作用,对Ipump也无显著作用。2)Zacopride通过特异性激动大鼠心肌细胞IK1电流抑制aconitine诱发的DADs(delayed after depolarization),TA和心室的心动过速。3)Zacopride可以抗室性心律失常,对心房的节律无影响。4)体外表达IK1通道的三种亚单位Kir2.1、Kir2.2和Kir2.3发现,zacopride只激动Kir2.1同源聚合体,对Kir2.2和Kir2.3的同源体和这三种亚单位任意组合的异聚体都无效。而心室肌IK1的构成是以Kir2.1为主的。***通过激动大鼠心肌细胞IK1通道发挥抗心室重构的作用:1)Zacopride对大鼠心室肥厚具有抗重构作用。2)Zacopride可以抑制ISO引发的延迟后除极和乌头碱引起的触发性心律失常。3)Zacopride减轻心肌肥厚大鼠心肌细胞Ca2+超载,抑制了促进心肌肥大基因表达的钙调蛋白激酶Ⅱ表达。这些研究为IK1激动剂的作用找到了分子靶点,理论上排除了激动心房肌IK1诱发房颤的可能。且Zacoprid还可以通过激动IK1发挥抗心室重构作用.
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