Increasing evidence suggests that the impaired neuroprotection of vesicular monoamine transporter 2（VMAT2）contributes to the pathogenesis of Parkinson＇s disease.That has been linked to aberrant subcellular retrogra...Increasing evidence suggests that the impaired neuroprotection of vesicular monoamine transporter 2（VMAT2）contributes to the pathogenesis of Parkinson＇s disease.That has been linked to aberrant subcellular retrograde trafficking as strongly indicated by recent genomic studies on familial Parkinson＇s diseases.However,whether VMAT2 function is regulated by retrograde trafficking is unknown.By using biochemistry and cell biology approaches,we have shown that VMAT2 was stringently localized to the trans-Golgi network and underwent retrograde trafficking in non-neuronal cells.The transporter also interacted with the key component of retromer,Vps35,biochemically and subcellularly.Using specific siRNA,we further showed that Vps35 depletion altered subcellular localization of VMAT2.Moreover,siRNA-mediated Vps35 knockdown also decreased the stability of VMAT2 as demonstrated by the reduced half-life.Thus,our work suggested that altered vesicular trafficking of VMAT2 may play a vital role in neuroprotection of the transporter as well as in the pathogenesis of Parkinson＇s disease.展开更多
目的:通过观察运动疲劳后大鼠初级运动皮层M1-纹状体通路局部场电位(Local field potential,LFPs)相位同步振荡活动,结合DA信号系统在运动疲劳后代谢表达变化,探讨皮层-纹状体通路电信号编码在运动疲劳中枢调控中的机制及其与黑质-纹状...目的:通过观察运动疲劳后大鼠初级运动皮层M1-纹状体通路局部场电位(Local field potential,LFPs)相位同步振荡活动,结合DA信号系统在运动疲劳后代谢表达变化,探讨皮层-纹状体通路电信号编码在运动疲劳中枢调控中的机制及其与黑质-纹状体DA系统的协同作用。方法:采用Wistar大鼠建立运动疲劳模型,分为对照组(CG),7天力竭运动即刻组(7FG)以及7天重复力竭运动24 h恢复组(24RG)。采用在体多通道电生理同步记录技术,结合实时视频录像观察M1及纹状体LFPs电振荡活动,分析皮层M1-纹状体同步振荡的相干性;采用免疫组化检测纹状体背外侧区DA受体及相关转运体蛋白在运动疲劳前后的表达。结果:1)与CG组相比,7FG组皮层M1区及纹状体α及β振荡增强(P<0.05),恢复24 h后较7FG组PSD值显著下降(P<0.05),且皮层M1-纹状体α及β振荡相干系数变大、同步性增强(P<0.05);2)与7FG组相比,24RG组相干系数及STWA比率均显著下降(P<0.05);3)与CG组相比,7FG组纹状体背外侧区D2DR表达降低,VMAT2表达上调且差异具有显著性(P<0.05);4)与7FG组相比,24RG组背外侧纹状体区D1DR表达显著降低(P<0.05)。结论:运动疲劳后,D2DR减少可能是导致突触后致密物厚度变化的原因之一,造成纹状体GABA能活动增强,使纹状体电活动增强,反馈至皮层影响皮层综合信号的输出,进而影响大鼠行为活动能力。表明皮层M1和纹状体脑区之间同步振荡活动的改变可能是运动疲劳症状产生的原因之一,且D2DR作为黑质-纹状体DA信号系统的关键受体,可作为改善运动疲劳的干预靶点。展开更多
This work was to develop a semi-automated synthesis of 18F-9-fluoropropyl-9-desmethyl-DTBZ (18F-FP-DTBZ) and validate its potential as a vesicular monoamine transporter 2 (VMAT2) ligand.18F-FP-DTBZ was synthesized by ...This work was to develop a semi-automated synthesis of 18F-9-fluoropropyl-9-desmethyl-DTBZ (18F-FP-DTBZ) and validate its potential as a vesicular monoamine transporter 2 (VMAT2) ligand.18F-FP-DTBZ was synthesized by a semi-automated procedure in a 21-35% yield without decay correction and with a radiochemical purity of >98%.Bioistribution in rats exhibited a favorable brain uptakes of the ligand (0.31±0.04 ID% at 60min post injection,n=8).The highest radioactivity located in VMAT2 enriched striatal tissue.The target-to-nontarget ratio (striatum/cerebellum,ST/CB) was 4.81±0.84.Blocking studies implied that striatum uptake could be blocked by DTBZ (a VMAT2 inhibitor) but could not by CFT (a dopamine transporter inhibitor).MicroPET imaging with 18F-FP-DTBZ in normal rats gave high quality images in which high radioactivity were observed in the striatal tissue.Time-and-activity curves revealed good retention in the target (striatum) and rapid clearance in the background (cerebellum),which resulted in a maximum ST/CB ratio of 5.08±0.81 (n=3) in 80-120min.By contrast,the 6-hydroxydopamine unilateral lesioned rats gave asymmetrical striata images with higher 18F-FP-DTBZ concentration on the unlesioned side (unlesioned-ST/CB=5.21±0.38,n=3) than the lesioned (lesioned-ST/CB=2.34±0.51).The results validated that 18F-FP-DTBZ is a favorable PET ligand binding to VMAT2.展开更多
基金supported by the National Nature Science Foundation of China(Grant No.31371436 and No.8157051134)by the laboratory start-up grant from Nanjing Medical University to Y.Liu
文摘Increasing evidence suggests that the impaired neuroprotection of vesicular monoamine transporter 2（VMAT2）contributes to the pathogenesis of Parkinson＇s disease.That has been linked to aberrant subcellular retrograde trafficking as strongly indicated by recent genomic studies on familial Parkinson＇s diseases.However,whether VMAT2 function is regulated by retrograde trafficking is unknown.By using biochemistry and cell biology approaches,we have shown that VMAT2 was stringently localized to the trans-Golgi network and underwent retrograde trafficking in non-neuronal cells.The transporter also interacted with the key component of retromer,Vps35,biochemically and subcellularly.Using specific siRNA,we further showed that Vps35 depletion altered subcellular localization of VMAT2.Moreover,siRNA-mediated Vps35 knockdown also decreased the stability of VMAT2 as demonstrated by the reduced half-life.Thus,our work suggested that altered vesicular trafficking of VMAT2 may play a vital role in neuroprotection of the transporter as well as in the pathogenesis of Parkinson＇s disease.
文摘目的:通过观察运动疲劳后大鼠初级运动皮层M1-纹状体通路局部场电位(Local field potential,LFPs)相位同步振荡活动,结合DA信号系统在运动疲劳后代谢表达变化,探讨皮层-纹状体通路电信号编码在运动疲劳中枢调控中的机制及其与黑质-纹状体DA系统的协同作用。方法:采用Wistar大鼠建立运动疲劳模型,分为对照组(CG),7天力竭运动即刻组(7FG)以及7天重复力竭运动24 h恢复组(24RG)。采用在体多通道电生理同步记录技术,结合实时视频录像观察M1及纹状体LFPs电振荡活动,分析皮层M1-纹状体同步振荡的相干性;采用免疫组化检测纹状体背外侧区DA受体及相关转运体蛋白在运动疲劳前后的表达。结果:1)与CG组相比,7FG组皮层M1区及纹状体α及β振荡增强(P<0.05),恢复24 h后较7FG组PSD值显著下降(P<0.05),且皮层M1-纹状体α及β振荡相干系数变大、同步性增强(P<0.05);2)与7FG组相比,24RG组相干系数及STWA比率均显著下降(P<0.05);3)与CG组相比,7FG组纹状体背外侧区D2DR表达降低,VMAT2表达上调且差异具有显著性(P<0.05);4)与7FG组相比,24RG组背外侧纹状体区D1DR表达显著降低(P<0.05)。结论:运动疲劳后,D2DR减少可能是导致突触后致密物厚度变化的原因之一,造成纹状体GABA能活动增强,使纹状体电活动增强,反馈至皮层影响皮层综合信号的输出,进而影响大鼠行为活动能力。表明皮层M1和纹状体脑区之间同步振荡活动的改变可能是运动疲劳症状产生的原因之一,且D2DR作为黑质-纹状体DA信号系统的关键受体,可作为改善运动疲劳的干预靶点。
基金Supported by the National Natural Science Foundation of China (30970844)the Outstanding Medical Professionals Foundation of Jiangsu Province (RC2011096)Natural Science Foundation of Jiangsu Province of China (BK2010155)
文摘This work was to develop a semi-automated synthesis of 18F-9-fluoropropyl-9-desmethyl-DTBZ (18F-FP-DTBZ) and validate its potential as a vesicular monoamine transporter 2 (VMAT2) ligand.18F-FP-DTBZ was synthesized by a semi-automated procedure in a 21-35% yield without decay correction and with a radiochemical purity of >98%.Bioistribution in rats exhibited a favorable brain uptakes of the ligand (0.31±0.04 ID% at 60min post injection,n=8).The highest radioactivity located in VMAT2 enriched striatal tissue.The target-to-nontarget ratio (striatum/cerebellum,ST/CB) was 4.81±0.84.Blocking studies implied that striatum uptake could be blocked by DTBZ (a VMAT2 inhibitor) but could not by CFT (a dopamine transporter inhibitor).MicroPET imaging with 18F-FP-DTBZ in normal rats gave high quality images in which high radioactivity were observed in the striatal tissue.Time-and-activity curves revealed good retention in the target (striatum) and rapid clearance in the background (cerebellum),which resulted in a maximum ST/CB ratio of 5.08±0.81 (n=3) in 80-120min.By contrast,the 6-hydroxydopamine unilateral lesioned rats gave asymmetrical striata images with higher 18F-FP-DTBZ concentration on the unlesioned side (unlesioned-ST/CB=5.21±0.38,n=3) than the lesioned (lesioned-ST/CB=2.34±0.51).The results validated that 18F-FP-DTBZ is a favorable PET ligand binding to VMAT2.
