Human embryonic dopamine-neuron transplants survive in patients with severe Parkinson's disease and result in some clinical benefit in younger but not in older patients.

DJ-1 is the third gene that has been linked to Parkinson disease.Mutations in the DJ-1 gene cause early onset PD with autosomal recessive inheritance. To clarify the mechanism of DJ-1 protection, we have overexpressed the gene in cultured dopaminergic cells that were then subjected to chemical stress. In the rat dopaminergic cell line, N27, and in primary dopamine neurons, overexpression of wild type DJ-1 protected cells from death induced by hydrogen peroxide and 6-hydroxydopamine. Overexpressing the L166P mutant DJ-1 had no protective effect. By contrast, knocking down endogenous DJ-1 with antisense DJ-1 rendered cells more susceptible to oxidative damage. We have found that DJ-1 improves survival by increasing cellular glutathione levels through an increase in the rate-limiting enzyme glutamate cysteine ligase. Blocking glutathione synthesis eliminated the beneficial effect of DJ-1. Protection could be restored by adding exogenous glutathione. Wild type DJ-1 reduced cellular reactive oxygen species and reduced the levels of protein oxidation caused by oxidative stress. By a separate mechanism, overexpressing wild type DJ-1 inhibited the protein aggregation and cytotoxicity usually caused by A53T human ␣-synuclein. Under these circumstances, DJ-1 increased the level of heat shock protein 70 but did not change the glutathione level. Our data indicate that DJ-1 protects dopaminergic neurons from oxidative stress through up-regulation of glutathione synthesis and from the toxic consequences of mutant human ␣-synuclein through increased expression of heat shock protein 70. We conclude that DJ-1 has multiple specific mechanisms for protecting dopamine neurons from cell death. Parkinson disease (PD)2 is a common neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra and by the presence of intracellular inclusions called Lewy bodies (1, 2). The etiology of PD may involve both genetic and environmental factors (3). In recent years, several genes linked to PD have been discovered. ␣-Synuclein was the first gene identified whose mutations, A53T and A30P, cause autosomal dominant forms of PD (4, 5). Importantly, aggregated ␣-synuclein has been found to be a major component of Lewy bodies (6). Mutations in a second gene, Parkin, cause early onset PD with autosomal recessive inheritance (7). Parkin is an ubiquitinprotein isopeptide ligase controlling protein degradation through the ubiquitin-proteasome system (8).DJ-1 is the third PD gene identified and is linked to early onset disease with autosomal recessive inheritance (9). Eleven different mutations have been found in the DJ-1 gene including missense, truncation, and splice site mutations as well as large deletions, suggesting that loss of DJ-1 function leads to neurodegeneration (9 -11). DJ-1 is a 189-amino acid protein with multiple functions (12). DJ-1 interacts with H-ras to increase cell transformation (13). DJ-1 is a regulatory subunit of an RNA-binding protein complex (14). Through binding to PIASx␣, the transcription...

Fetal-tissue implants appear to offer long-term clinical benefit to some patients with advanced Parkinson's disease.

Mouse and human fibroblasts have been transformed into induced pluripotent stem (iPS) cells by retroviral transduction or plasmid transfection with four genes. Unfortunately, viral and plasmid DNA incorporation into chromosomes can lead to disruption of gene transcription and malignant transformation. Tumor formation has been found in offspring of mice generated from blastocysts made mosaic with iPS cells. To proceed with iPS cells for human therapy, reprogramming should be done with transient gene expression. Recently, adenoviral vectors have been used to produce mouse iPS cells without viral integration. Here, we report the successful creation of human iPS cells from embryonic fibroblasts using adenoviral vectors expressing c-Myc, Klf4, Oct4, and Sox2. After screening 12 colonies, three stable iPS cell lines were established.Each cell line showed human embryonic stem cell morphology and surface markers. Southern blots and polymerase chain reaction demonstrated that there was no viral DNA integration into iPS cells. Fingerprinting and karyotype analysis confirmed that these iPS cell lines are derived from the parent human fibroblasts. The three human iPS cell lines can differentiate to all three germ layers in vitro, including dopaminergic neurons. After s.c. injection into nonobese diabetic-severe combined immunodeficient mice, each human iPS line produced teratomas within 5 weeks postimplantation. We conclude that adenoviral vectors can reprogram human fibroblasts to pluripotent stem cells for use in individualized cell therapy without the risk for viral or oncogene incorporation. STEM

Placebo-associated improvements have been previously documented in small series of Parkinson's disease (PD) patients. Using a strict definition of placebo-associated improvement, we examined rates and timing of placebo responses to identify patient- and study-based characteristics, predicting positive placebo response in several PD clinical trials. We collected individual patient data from the placebo groups of 11 medical and surgical treatment trials involving PD patients with differing PD severities and placebo-assignment likelihoods. We defined a positive placebo response as > or = 50% improvement in total Unified Parkinson's Disease Rating Scale motor (UPDRSm) score or a decrease by > or = 2 points on at least two UPDRSm items compared to baseline. We calculated positive placebo response rates at early (3-7 weeks), mid (8-18 weeks), and late (23-35 weeks) stages of follow-up. Odds ratios for patient- and study-based characteristics were obtained from a model fitted using generalized estimating equations. There were 858 patients on placebo who met inclusion criteria for analysis. Three studies involved patients without need of symptomatic treatment, two involved patients without motor fluctuations needing symptomatic treatment, and six (three medical and three surgical) involved patients with motor fluctuations. The overall placebo response rate was 16% (range: 0-55%). Patients with higher baseline UPDRSm scores and studies that focused on PD with motor fluctuations, surgical interventions, or those with a higher probability of placebo assignment showed increased odds of positive placebo response. Placebo responses were temporally distributed similarly during early, mid, and late phases of follow-up. Placebo-related improvements occur in most PD clinical trials and are similarly distributed across all 6 months of follow-up. Recognition of factors that impact placebo response rates should be incorporated into individual study designs for PD clinical trials.

No abstract

The placebo effect was very strong in this study, demonstrating the value of placebo-controlled surgical trials.

We have previously reported the results of a 1-y double-blind, placebo-controlled study of embryonic dopamine cell implantation for Parkinson's disease. At the end of the blinded phase, we found a significant increase in putamen uptake on 18 F-fluorodopa ( 18 F-FDOPA) PET reflecting the viability of the grafts. Nonetheless, clinical improvement was significant only in younger (age # 60 y) transplant recipients, as indicated by a reduction in Unified Parkinson's Disease Rating Scale (UPDRS) motor scores. Methods: We now report long-term clinical and PET outcomes from 33 of the original trial participants who were followed for 2 y after transplantation and 15 of these subjects who were followed for 2 additional years. Longitudinal changes in UPDRS motor ratings and caudate and putamen 18 F-FDOPA uptake were assessed with repeated-measures ANOVA. Relationships between these changes over time were evaluated by the analysis of within-subject correlations. Results: We found that UPDRS motor ratings declined over time after transplantation (P , 0.001). Clinical improvement at 1 y was relatively better for the younger transplant recipients and for men, but these age and sex differences were not evident at longer-term follow-up. Significant increases in putamen 18 F-FDOPA uptake were evident at all posttransplantation time points (P , 0.001) and were not influenced by either age or sex. Posttransplantation changes in putamen PET signal and clinical outcome were significantly intercorrelated (P , 0.02) over the course of the study. Image analysis at the voxel level revealed significant bilateral increases in 18 F-FDOPA uptake at 1 y (P , 0.001) in the posterior putamen engraftment sites. PET signal in this region increased further at 2 and 4 y after engraftment. Concurrently, this analysis disclosed progressive declines in radiotracer uptake in the nonengrafted caudate and ventrorostral putamen. Clinical improvement after transplantation correlated with the retention of PET signal in this region at the preoperative baseline. Conclusion: These results suggest that clinical benefit and graft viability are sustained up to 4 y after transplantation. Moreover, the dependence of clinical (but not imaging) outcomes on subject age and sex at 1 y may not persist over the long term. Last, the imaging changes reliably correlate with clinical outcome over the entire posttransplantation time course.