Event-related potential changes due to early-onset Parkinson’s disease in parkin (PARK2) gene mutation carriers and non-carriers

ObjectiveTo investigate cognitive functions in non-demented patients with early-onset Parkinson's disease (PD), and to compare PARK2 gene mutation carriers and non-carriers by means of event-related brain potentials (ERPs).MethodsThe participants comprised patients with early-onset PD (EOPD) and healthy controls (HC). Patients with EOPD were divided into two groups as carriers of known pathogenic variants of PARK2 gene (EOPD-PC) and non-carriers of genes involved in familial PD (EOPD-NC). ERP data were collected during auditory oddball and visual continuous performance test (CPT).ResultsBoth EOPD groups (EOPD-PC and EOPD-NC) displayed reduced and delayed P3 in response to oddball target and CPT NoGo. CPT Go P3 was reduced in EOPD-NC but not in EOPD-PC. Oddball target N1 was reduced and P2 was enhanced in both EOPD-PC and EOPD-NC. In both cognitive tasks, RTs were prolonged and accuracy was lower in EOPD-PC and EOPD-NC.ConclusionsWe found several EOPD-related neurophysiologic changes, implying impairments in cognitive functions. Pairwise comparisons between EOPD-PC and EOPD-NC revealed no significant ERP marker.SignificanceIn this study, the confounding effect of normative aging was somewhat excluded compared with many previous studies. In contrast with the many oddball studies in non-demented PD, we clearly observed reduced and prolonged P3 in early-onset PD. Our NoGo P3 findings also contribute to the limited ERP research concerning response inhibition.     

Construction and validation of a Parkinson's disease mutation genotyping array for the Parkin gene.

Parkin mutations account for the majority of familial and sporadic early onset Parkinson's disease (EOPD) cases with a known genetic association. More than 100 mutations have been described in the Parkin gene that includes homozygous, compound heterozygous, and single heterozygous mutations. We have designed a Parkin mutation genotyping array (gene chip) that includes published Parkin sequence variants and allows their simultaneous detection. The chip was validated by screening 85 PD cases and 47 controls previously tested for Parkin mutations. Similar genotyping microarrays have been developed for other genetically heterogeneous diseases including age-related macular degeneration. Here, we show the utility of a genotyping array for Parkinson's disease by analysis of 60 subjects from the Genetic Epidemiology of Parkinson Disease (GEPD) study that includes 15 early-onset PD case probands and 45 relatives.     

Genetic predisposition to leprosy: A major gene reveals novel pathways of immunity to Mycobacterium leprae

The elucidation of the genetic control of susceptibility to common infectious diseases is expected to provide new and more effective tools for prevention and control of some of the most pressings health needs on a global scale. A major advantage of whole genome based genetic approaches is that no a priori assumptions about mechanisms of pathogenesis need to be made in these studies. Hence, genetic studies can identify previously unrecognized pathways of disease susceptibility and tag critical pathogenic events for further biochemical, immunological or physiological analysis. We have applied this strategy to leprosy, a disease that still claims 400,000 new cases each year. We identified genetic variants in the shared promoter region of the PARK2 and PACRG genes as major risk factors of leprosy susceptibility. Both encoded proteins are part of the cellular ubiquitination system. Specifically, PARK2, the cause of early onset Parkinson's disease, is an E3 ligase that likely is involved in controlled proteolysis, the cellular anti-oxidants response and the regulation of innate immune responsiveness. In addition, numerous E3 ligases have recently been shown to be critical regulators of immunity. While the specific role of PARK2/PACRG in leprosy pathogenesis remains unknown, a number of experimentally testable scenarios can be developed to further explore the role of these proteins in anti-Mycobacterium leprae host responsiveness.     

枳实-白术调节PINK1/Parkin信号通路介导的线粒体自噬改善慢传输型便秘大鼠结肠动力障碍

目的：基于线粒体自噬及磷酸酶及张力蛋白同源物诱导的蛋白激酶1(PINK1)/帕金蛋白(Parkin)通路观察枳实、白术及其配伍对慢传输型便秘大鼠结肠动力障碍的改善作用,为临床精准用药提供理论参考。方法：将56只雄性SD大鼠按体质量随机分成正常组、模型组、自然恢复组、枳实组、白术组、枳实-白术组和莫沙必利组,每组各8只。除正常组外,采用洛哌丁胺连续14 d灌胃(3 mg·kg^-1·d^-1)构建慢传输型便秘大鼠模型。造模成功后,除模型组继续洛哌丁胺诱导外,正常组和自然恢复组采用0.9%生理盐水灌胃,枳实组(1.35 g·kg^-1·d^-1)、白术组(2.7 g·kg^-1·d^-1)、枳实-白术组(4.05 g·kg^-1·d^-1)和莫沙必利组(1.56 mg·kg^-1·d^-1)大鼠分别给予相应的药物灌胃,连续7 d。观察药物对大鼠粪便数量、粪便含水率及小肠推进率的影响;苏木素-伊...     

Parkin基因甲基化在鼻咽癌发生发展中的作用

目的探讨Parkin基因甲基化在鼻咽癌发生发展中的作用。方法应用甲基化特异性PCR技术对5个鼻咽癌细胞株（CNE1、CNE2、TW03、HONE1、C666）和1个正常鼻咽上皮细胞株（NP69）、54例鼻咽癌组织和16例正常鼻咽上皮组织的Parkin基因启动子区甲基化状态进行检测,并分析鼻咽癌组织中Parkin基因甲基化与临床特征的关系;应用RT-PCR检测加入甲基转移酶抑制剂（5-氮-2-脱氧胞苷）后CNE1、CNE2中Parkin基因转录表达,分析去甲基化对Parkin基因转录表达的影响。结果1个正常鼻咽上皮细胞株和16例正常鼻咽上皮组织中均未检测到Parkin基因甲基化;5个鼻咽癌细胞株和54例鼻咽癌组织中Parkin基因甲基化频率分别为60.00%和62.96%;54例鼻咽癌患者中Parkin基因甲基化状态与临床因素均无关（均P＞0.05）。经过5-氮-2-脱氧胞苷处理后,Parkin基因在CNE1、CNE2中转录表达增加,分别从0提高至3.65和2.15。结论鼻咽癌中Parkin基因甲基化与转录表达密切相关,是基因表达调节的一种重要方式;可能成为鼻咽癌早期分子生物学辅助诊断的标志物和去甲基化基因治疗的靶点。     

自噬对肾小管细胞毒性损伤后线粒体功能的影响及相关机制研究

目的研究自噬对肾小管细胞毒性损伤后线粒体功能的影响及相关机制。方法将人近曲肾小管上皮细胞(HK-2)分为杂化siRNA组(对照无关序列片段siRNA转染细胞)、杂化siRNA+顺铂组(对照无关序列片段siRNA转染细胞+10μmol/L顺铂溶液)、沉默Pink1+顺铂组(Pink1沉默转染细胞+10μmol/L顺铂溶液)和沉默Parkin+顺铂组(Parkin沉默转染细胞+10μmol/L顺铂溶液)。培养12 h后,细胞计数试剂盒8(CCK-8)法测定各组细胞存活率,JC-1法检测线粒体膜电位,荧光法检测各组细胞内三磷酸腺苷(ATP)的含量,Western blotting和免疫荧光探针检测自噬相关蛋白的相对表达。结果杂化siRNA+顺铂组的细胞存活率为(88.2±2.7)%,显著低于杂化siRNA组[(101.3±3.1)%](P<0.05);沉默Pink1+顺铂组和沉默Parkin+顺铂组的存活率为(80.1±2.3)%、(79.4±3.0%),显著低于杂化siRNA+顺铂组(P<0.05)。杂化siRNA+顺铂组的线粒体膜电位和ATP含量为(0.90±0.01)、(0.82±0.01)nmol/mg,显著低于杂化siRNA组[(1.01±0.02)、(1.00±0.04)nmol/mg](P<0.05);沉默Pink1+顺铂组和沉默Parkin+顺铂组的线粒体膜电位(0.79±0.02、0.77±0.02)和ATP[(0.66±0.05)、(0.66±0.02)nmol/mg]含量显著低于杂化siRNA+顺铂组(P<0.05)。杂化siRNA+顺铂组的Pink1、Parkin、Beclin蛋白的相对表达量和LC3Ⅱ/LC3Ⅰ的比值(1.68±0.04、1.80±0.05、1.87±0.05、2.01±0.04)显著高于杂化siRNA组(1.00±0.04、1.00±0.05、1.01±0.01、1.04±0.02)(P<0.05);而沉默Pink1+顺铂组和沉默Parkin+顺铂组的Pink1、Parkin、Beclin蛋白的相对表达量和LC3Ⅱ/LC3Ⅰ的比值(1.17±0.05、0.69±0.05、1.37±0.05、1.43±0.02;1.22±0.04、0.57±0.06、1.39±0.03、1.38±0.10)显著低于杂化siRNA+顺铂组(P<0.05)。杂化siRNA+顺铂组的自噬阳性点数为(12.2±0.7)个,显著多于杂化siRNA组[(2.4±0.3)个](P<0.05);而沉默Pink1+顺铂组和沉默Parkin+顺铂组的荧光点数[(5.3±0.8)、(5.6±0.5)个]显著少于杂化siRNA+顺铂组(P<0.05)。结论顺铂处理可诱导HK-2细胞的线粒体自噬作用,从而改善顺铂引起的肾小管细胞毒性损伤和线粒体功能,其作用机制可能与Pink1/Parkin蛋白的表达情况有关。     

针刺对运动性骨骼肌损伤大鼠骨骼肌线粒体自噬的影响

目的:通过观察针刺对大负荷运动大鼠骨骼肌线粒体自噬相关蛋白表达的影响,探讨针刺在运动性骨骼肌损伤修复中的作用及其机制。方法:将128只成年雄性Sprague-Dawley大鼠随机分为4组:空白对照(control,C;n=8)组、单纯运动(exercise,E;n=40)组、单纯针刺(acupuncture,A;n=40)组和运动针刺(exercise and acupuncture,EA;n=40)组。其中,E和EA组进行1次下坡跑运动,A组和EA组(运动后即刻)施加针刺处理。后3组根据干预后不同时相又分为0 h、12 h、24 h、48 h和72 h亚组(n=8),分别于对应时点分离比目鱼肌进行检测,使用透射电子显微镜观察骨骼肌线粒体超微结构变化;采用ELISA法检测比目鱼肌线粒体定量酶柠檬酸合成酶(CS)的含量变化;应用Western blot法检测骨骼肌PTEN诱导假定激酶1(PINK1)、parkin和微管相关蛋白1轻链3(LC3)的蛋白表达变化。结果:1次大负荷运动后大鼠比目鱼肌线粒体出现明显肿胀和肌膜下积聚等超微结构异常变化,伴有大量自噬体形成;同时CS的含量明显减少(P0.05);线粒体自噬蛋白PINK1、parkin和LC3均出现一过性的表达升高(P0.05)。运动后针刺明显改善了线粒体超微结构的异常变化,减少自噬溶酶体的出现,同时抑制CS的含量减少,下调PINK1、parkin和LC3在线粒体上的表达(P0.05)。结论:1次大负荷运动后骨骼肌线粒体结构和数量受损,通过激活PINK1/parkin途径诱发线粒体自噬的过度发生。大负荷运动后针刺可以缓解骨骼肌线粒体的损伤,其作用机制可能是通过下调线粒体外膜蛋白PINK1表达,抑制其对下游胞浆蛋白parkin的招募,进而影响LC3与线粒体的结合以抑制线粒体自噬过度激活。