帕金森病相关致病基因的研究进展

近年来，帕金森病(PD)的遗传学研究取得了较大的进展，迄今为止已经确定了PARK1-PARK10等10个单基因与PD的发生有关。其中三个基因产物与家族性PD有关，它们分别是a-synuclein(PARK1)、parkin(PARK2)和泛素蛋白C末端羟化酶-L1(PARK5)，它们均参与Lewy小体．的形成，在PD的发病过程中扮演重要的角色。虽然另外几个基因对应的蛋白或对应蛋白的功能未知，但已经在染色体上找到相应的位置。PD遗传学的研究将有助于PD的早期诊断．并且有可能为PD的治疗提供新的靶点。本文概述了PD相关基因的最新研究进展。     

Case-control study of the alpha-synuclein interacting protein gene and Parkinson's disease.

We conducted a case-control study of the alpha-synuclein-interacting protein gene (SNCAIP, also known as synphilin-1) and Parkinson's disease (PD). A total of 319 PD cases and 195 controls were genotyped for four SNCAIP variants, including a microsatellite repeat in intron 4 and three restriction fragment length polymorphisms (RFLP) proximal to the 5' terminal of exons 1, 4, and 6. None of the variants were found associated with PD overall. Global score statistics were not significant for four, three, and two loci haplotypes. All four loci were in linkage disequilibrium for cases, controls, or both groups combined (P < 0.0001). Recursive partitioning showed no interactions between variants of the SNCAIP gene and variants of the alpha-synuclein gene (SNCA) or the parkin (PARK2) gene.     

Point Mutation in the Parkin Gene on Patients with Parkinson''''s Disease

Summary;To investigate the distribution of possible novel mutations from parkin gene in variant sub-set of patients with Parkinson’s disease(PD)in China and explore whether parkin gene plays an im-portant role in the pathogenesis of PD,70 patients were divided into early-onset group and late-onsetgroup; 70 healthy subjects were included as controls.Genomic DNA from 70 normal controls andfrom those of PD patients were extracted from peripheral blood leukocytes by using standard proce-dures.Mutations of parkin gene(exon 1—12)in all the subjects were screened by PCR-single strandconformation polymorphism(SSCP),and further sequencing was performed in tue samples with ab-normal SSCP results,in order to confirm the mutation and its location.A new missense mutationGly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 pa-tients were found.All the DNA variants were sourced from the samples of the patients with early-on-set PD.It was concluded that Parkin point mutation a     

Point mutation in the parkin gene on patients with Parkinson’s disease

Summary To investigate the distribution of possible novel mutations from parkin gene in variant subset of patients with Parkinson’s disease (PD) in China and explore whether parkin gene plays an important role in the pathogenesis of PD, 70 patients were divided into early-onset group and late-onset group; 70 healthy subjects were included as controls. Genomic DNA from 70 normal controls and from those of PD patients were extracted from peripheral blood leukocytes by using standard procedures. Mutations of parkin gene (exon 1–12) in all the subjects were screened by PCR-single strand conformation polymorphism (SSCP), and further sequencing was performed in the samples with abnormal SSCP results, in order to confirm the mutation and its location. A new missense mutation Gly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 patients were found. All the DNA variants were sourced from the samples of the patients with early-onset PD. It was concluded that Parkin point mutation also partially contributes to the development of early-onset Parkinson’s disease in Chinese. WANG Tao, male, born in 1961, Associate Professor This work was supported by grants from the key program of the special scientific project of Scientific & Technologic Agency of Hubei Province (Serial No. 2001AA308B01) and the Hygienic Research Project of Hygienic Agency of Hubei province (Serial No. WJ 01529).     

Large French-Canadian family with Lewy body parkinsonism: exclusion of known loci.

The identification of rare, large families with Parkinson's disease (PD) has provided important clues that have contributed to our understanding of this complex disorder. We have identified a large French-Canadian kindred that spans five generations consisting of more than 90 individuals. A total of 65 individuals now have been examined, had venous blood drawn, and DNA extracted. Two-point and multipoint linkage analysis was performed to assess linkage to known PD genes or loci. Within the third and fourth generations of this family there are 10 living, plus 3 deceased members with well-documented levodopa responsive parkinsonism. Autopsy results on 1 member demonstrated the loss of pigmented neurons in the substantia nigra and the presence of alpha-synuclein positive Lewy bodies. Four of the PD patients have prominent postural and kinetic tremors that preceded their parkinsonism by up to 10 years. Two other individuals within the family have prominent isolated postural and kinetic tremors without parkinsonism. The alpha-synuclein(4q21.3-23), Parkin(6q25.2-27), PARK3 (2p13), PARK4, and ubiquitin carboxy terminal hydrolase-L1 (4p14-16.3) and PARK6 and PARK7 (1p35-36) loci were excluded in this kindred using closely linked markers. The clinical and pathological features of this family are consistent with the diagnosis of PD. This family further demonstrates the known genetic heterogeneity in PD and is large enough that a genome-wide screen has been undertaken in an effort to identify a novel PD gene.     

人野生型parkin基因真核表达载体的构建及其在PC12细胞中的表达

目的 克隆人野生型parkin基因并构建真核表达载体pCDNA3．1—parkin，将重组质粒转染PC12细胞获得高表达人野生型parkin基因的PC12细胞克隆。方法 从胎脑组织中提取总RNA，用RT—PCR方法获得人野生型parkin基因的全长cDNA，插入pCR2．1—TA克隆载体中进行序列测定，测序正确后将其亚克隆至表达载体pCD—NA3．1，利用脂质体将重组质粒转染PC12细胞，经G418筛选获得抗性细胞克隆，采用RT—PCR和Western Blot方法鉴定人野生型parkin基因在PC12细胞中的过表达。结果 经限制性内切酶酶切图谱分析和DNA序列测定证实目的基因已插入重组质粒，RT—PCR和Western Blot证明经G418筛选得到的转基因PC12细胞克隆中存在人野生型parkin基因的表达。结论 成功构建了人野生型parkin基因的真核表达载体，获得了稳定表达人野生型parkin基因的PC12细胞克隆，为进一步研究parkin的生物学功能以及parkin在帕金森病发病机制中的作用奠定了良好的基础。     

18F]-Dopa positron emission tomography imaging in early-stage, non-parkin juvenile parkinsonism.

There are few reports of positron emission tomography (PET) in juvenile parkinsonism (JP). We report on the results of (18)F-6-fluoro-L-dopa (FD) PET in a 14-year-old patient with JP of 5 years duration associated with atypical features. This is the youngest subject to be investigated to date. There was a severe asymmetric reduction in striatal FD uptake, with a rostrocaudal gradient in the putamen similar to that seen in adult-onset idiopathic parkinsonism. Extensive DNA analysis in this patient did not show mutations in the parkin gene.     

The effects of parkin suppression on the behaviour, amyloid processing, and cell survival in APP mutant transgenic mice

Parkin suppression induces accumulation of β-amyloid in mutant tau mice. We studied the effect of parkin suppression on behaviour and brain pathology in APP_swe mutant mice. We produced double mutant mice with human mutated APP_swe + partial (hemizygote) or total (homozygote) deletion of Park-2 gene. We studied the development, behaviour, brain histology, and biochemistry of 12- and 16-month-old animals in 6 groups of mice, with identical genetic background: wild-type (WT), APP_swe overexpressing (APP), hemizygote and homozygote deletion of Park-2 (PK^+/− and PK^−/−, respectively), and double mutants (APP/PK^+/− and APP/PK^−/−).APP mice have reduced weight gain, decreased motor activity, and reduced number of entrances and of arm alternation in the Y-maze, abnormalities which were partially or completely normalized in APP/PK^+/− and APP/PK^−/− mice. The double mutants had similar number of mutant human APP transgene copies than the APP and levels of 40 and 80 kDa proteins; but both of them, APP/PK^+/− and APP/PK^−/− mice, had less plaques in cortex and hippocampus than the APP mice. APP mutant mice had increased apoptosis, proapoptotic Bax/Bcl2 ratios, and gliosis, but these death-promoting factors were normalized in APP/PK^+/− and APP/PK^−/− mice. APP mutant mice had an increased number of tau immunoreactive neuritic plaques in the cerebral cortex as well as increased levels of total and phosphorylated tau protein, and these changes were partially normalized in APP/PK^+/− heterozygotic and homozygotic APP/PK^−/− mice. Compensatory protein-degrading systems such as HSP70, CHIP, and macroautophagy were increased in APP/PK^+/− and APP/PK^−/−. Furthermore, the chymotrypsin- and trypsin-like proteasome activities, decreased in APP mice in comparison with WT, were normalized in the APP/PK^−/− mice.We proposed that partial and total suppression of parkin triggers compensatory mechanisms, such as chaperone overexpression and increased autophagy, which improved the behavioural and cellular phenotype of APP_swe mice.     

三个常染色体隐性遗传性青少年型帕金森综合征家系的基因型与表型分析

目的探讨常染色体隐性遗传性青少年型帕金森综合征(autosomal recessive juvenile parkinson-ism,AR-JP)parkin基因的突变及临床特征。方法应用聚合酶链反应、DNA测序和限制性核酸内切酶酶切等技术对15个AR-JP家系先证者的parkin基因进行突变研究。结果发现3个家系有parkin基因的突变,其中2个家系含parkin基因的杂合缺失突变,分别为第2外显子的202-203delAG及第9外显子的1069-1074delGTGTCC;另一家系发现一个杂合点突变,为第12外显子的1422(T→C)。其中1069-1074delGTGTCC和1422(T→C)为新的突变。3个家系共6名患者,发病年龄18~31岁,平均25.2±5.7岁;病情进展慢,腱反射活跃或亢进、症状波动常见;对小剂量多巴制剂反应良好。结论我国的AR-JP家系存在parkin基因的突变;含parkin基因突变的AR-JP患者有帕金森病的一般临床表现,又有其独特的临床特征。     

Are parkin patients particularly suited for deep‐brain stimulation?

Patients with parkin mutations are known to have slower PD progression and a better response to levodopa at lower doses than patients with idiopathic Parkinson's disease. To determine the effects of deep brain stimulation (DBS) on such patients, we have compared the follow‐up after surgery of 7 patients with one parkin mutation, 7 patients with two parkin mutations, and 39 patients without parkin mutations. Twelve to 24 months after neurosurgery, the daily doses of levodopa equivalent were significantly lower in patients with two parkin mutations, indicating that these patients benefit from DBS, and they might have more durable results. © 2008 Movement Disorder Society