Project description:Creutzfeldt-Jakob disease (CJD) is characterized by a broad phenotypic spectrum regarding symptoms, progression, and molecular features. Current sporadic CJD (sCJD) classification recognizes six main clinical-pathological phenotypes. This work investigates the molecular basis of the phenotypic heterogeneity of prion diseases through a multi-omics analysis of the two most common sCJD subtypes: MM1 and VV2. We performed DNA target sequencing on 118 genes on a cohort of 48 CJD patients and full exome RNA sequencing on post-mortem frontal cortex tissue on a subset of this cohort. DNA target sequencing identified multiple potential genetic contributors to the disease onset and phenotype, both in terms of coding, damaging-predicted variants, and enriched groups of SNPs in the whole cohort and the two subtypes. The results highlight a different functional impairment, with VV2 associated with higher impairment of the pathways related to dopamine secretion, regulation of calcium release and GABA signaling, showing some similarities with Parkinson's disease both on a genomic and a transcriptomic level. MM1 showed a gene expression profile with several traits shared with different neurodegenerative, without an apparent distinctive characteristic or similarities with a specific disease. In addition, integrating genomic and transcriptomic data led to the discovery of several sites of ADAR-mediated RNA editing events, confirming and expanding previous findings in animal models. On the transcriptomic level, this work represents the first application of RNA sequencing on CJD human brain samples. Here, a good clusterization of the transcriptomic profiles of the two subtypes was achieved, together with the finding of several differently impaired pathways between the two subtypes. The results add to the understanding of the molecular features associated with sporadic CJD and its most common subtypes, revealing strain-specific genetic signatures and functional similarities between VV2 and Parkinson's disease and providing preliminary evidence of RNA editing modifications in human sCJD.
Project description:Sporadic Creutzfeldt-Jakob disease (sCJD) presents as a rapidly progressive dementia which is usually fatal within six months. No clinical blood tests are currently available for diagnosis or disease monitoring. Here, we profiled blood microRNA (miRNA) expression in sCJD. Small RNA-sequencing of 57 sCJD patients and 48 healthy controls revealed differential expression of hsa-let-7i-5p, hsa-miR-16-5p, hsa-miR-93-5p and hsa-miR-106b-3p. Downregulation of hsa-let-7i-5p, hsa-miR-16-5p and hsa-miR-93-5p replicated in an independent cohort using quantitative PCR, with concomitant upregulation of four of their mRNA targets. Absence of correlation in cross-sectional analysis with clinical phenotypes paralleled the lack of association between rate of decline in miRNA expression and rate of disease progression in a longitudinal cohort of 50 samples from 21 sCJD patients. Finally, the miRNA signature showed a high level of accuracy in discriminating sCJD from Alzheimer’s disease (AD). These findings highlight novel molecular alterations in the periphery in sCJD which can provide information about differential diagnosis and improve mechanistic understanding of human prion diseases.
Project description:Background and purposeSporadic Creutzfeldt-Jakob disease (sCJD) is a rapidly progressive neurodegenerative disease caused by an abnormal isoform of the human prion protein. Structural magnetic resonance imaging in patients with pathologically confirmed sCJD was compared with cognitively normal individuals to identify a cortical thickness signature of sCJD.MethodsThis retrospective cross-sectional study compared patients with autopsy-confirmed sCJD with dementia (n = 11) with age- and sex-matched cognitively normal individuals (n = 22). We identified regions of interest (ROIs) in which cortical thickness was most affected by sCJD. Within patients with sCJD, the relationship between ROI cortical thickness and clinical measures (disease duration, cerebrospinal fluid tau and diffusion-weighted imaging abnormalities) was evaluated.ResultsCompared with cognitively normal individuals, patients with sCJD had significantly reduced cortical thickness in multiple ROIs, including the fusiform gyrus, precentral gyrus, precuneus and superior temporal gyrus bilaterally; the caudal middle frontal gyrus, superior frontal gyrus, postcentral gyrus, inferior temporal gyrus and transverse temporal gyrus in the left hemisphere; and the superior parietal lobule in the right hemisphere. Only one patient with sCJD had co-pathology consistent with Alzheimer's disease. Reduced cortical thickness did not correlate with disease duration, presence of diffusion restriction or elevated cerebrospinal fluid tau.ConclusionCortical signature changes in sCJD may reflect brain changes not captured by standard clinical measures. This information may be used with clinical measures to inform the progression of sCJD and patterns of prion protein spread throughout the brain. These results may have implications for prediction of symptomatic progression and plausibly for development of therapeutic strategies.
Project description:Neuroinflammation is an essential part of neurodegeneration. Yet, current understanding of neuroinflamma-tion associated molecular events in distinct brain regions of prion disease patients is insufficient to lay the ground for effective treatment strategies targeting this complex neuropathological process. To address this problem, we analyzed expression of 800 neuroinflammation associated genes to create a profile of biological processes taking place in frontal cortex and cerebellum of patients, who suffered from sporadic Creutzfeldt-Jakob disease. The analysis was performed using NanoString nCounter technology, human neuroinflamma-tion panel+. The observed gene expression patterns indicate regionally, and sub-regionally common and dis-tinct molecular pathways associated with sporadic Creutzfeldt-Jakob disease pathogenesis. Moreover, the data show that the neuroinflammatory response in samples from the same brain region is variable. Based on the gene expression profiles from FC and CB, regional, neuroinflammatory patterns were observed.
Project description:The familial or genetic Creutzfeldt-Jakob disease (fCJD or gCJD) is the inherent form of human prion diseases, which accounts for approximately 10-15% of human prion diseases that are caused by mutations of the prion protein gene (PRNP). In this study, the global expression patterns of the parietal cortex from a patient with G114V gCJD were comparatively analyzed with the normal controls by using a commercial human genome expression chip. Totally 8774 genes showed differential expression, among them 2769 genes were upregulated and 6005 ones were downregulated. The reliability of the results was confirmed by the real-time RT-PCR assays for several specific genes. The most differentially expressed genes involved in the functions of regulation of transcription, ion transport, transcription, cell adhesion, signal transduction. The gene associated with gliosis was upregulated and the genes marked for neurons were downregulated, while the transcription of PRNP gene maintained unchanged. 169 different pathways showed significantly changed in the brain of G114V gCJD. The most significantly regulated pathways included that of Alzheimer’s and Parkinson’s disease, oxidative phosphorylation, regulation of actin cytoskeleton, MAPK signaling pathway and proteasome, which were described in prion diseases previously. In addition, some rarely addressed pathways in prion diseases, such as axon guidance, gap junction and purine metabolism, were also significantly changed in G114V gCJD. The transcriptional situations of the most genes in the top ten changed pathways were down-regulated. The extensive reductions of gene expressions in G114V gCJD showed the comparable profiles with sporadic CJD. The data here raised the useful clues for understanding the pathogenesis of the disease and selecting the potential biomarkers for diagnostic and therapeutic tools. Brain tissues of parietal cortex from a definitely diagnosed G114V gCJD were enrolled into this study. The patient was a 47-year-old Han-Chinese woman at the onset. Neuropathological assays of ten different brain regions revealed typical sCJD-like abnormality and PrPSc deposits. Meanwhile, a commercial normal human parietal cortex total RNA (Clontech) pooled from four male/female aged 35-89 was utilized as control.
Project description:Prion diseases are fatal and transmissible neurodegenerative disorders caused by the misfolding and aggregation of prion protein. Although recent studies have implicated epigenetic variation in common neurodegenerative disorders, no study has yet explored their role in human prion diseases. Here we profiled genome-wide blood DNA methylation in the most common human prion disease, sporadic Creutzfeldt-Jakob disease (sCJD). Our case-control study (n=219), when accounting for differences in cell type composition between individuals, identified 38 probes at genome-wide significance (p < 1.24x10-7). Nine of these sites were taken forward in a replication study, performed in an independent case-control (n=186) cohort using pyrosequencing. Sites in or close to FKBP5, AIM2 (2 probes), UHRF1, KCNAB2, PRNP, ANK1 successfully replicated. The blood-based DNA methylation signal was tissue- and disease-specific, in that the replicated probe signals were unchanged in case-control studies using sCJD frontal-cortex (n=84), blood samples from patients with Alzheimer’s disease, and from inherited and acquired prion diseases. Machine learning algorithms using blood DNA methylation array profiles accurately distinguished sCJD patients and controls. Finally, we identified sites whose methylation levels associated with prolonged survival in sCJD patients. Altogether, this study has identified a peripheral DNA methylation signature of sCJD with a variety of potential biomarker applications.
Project description:ObjectiveTo determine whether oral quinacrine increases survival in sporadic Creutzfeldt-Jakob disease (sCJD).MethodsThis NIH/National Institute on Aging-funded, double-blinded, placebo-controlled, stratified randomization treatment trial was conducted at the University of California, San Francisco from February 2005 through May 2009 (ClinicalTrials.gov, NCT00183092). Subjects were randomized (50:50) to quinacrine (300 mg daily) or placebo with inpatient evaluations at baseline, and planned for months 2, 6, and 12. Subjects returning for their month-2 visit were offered open-label quinacrine. The primary outcome was survival from randomization to month 2.ResultsOf 425 patients referred, 69 subjects enrolled, 54 subjects were randomized to active drug or placebo, and 51 subjects with sCJD were included in survival analyses. Survival for the randomized portion of the trial (first 2 months) showed no significant difference between the 2 groups (log-rank statistic, p = 0.43; Cox proportional relative hazard = 1.43, quinacrine compared with placebo, 95% confidence interval = 0.58, 3.53). The quinacrine-treated group, however, declined less on 2 of 3 functional scales, the modified Rankin and Clinical Dementia Rating, than the placebo group during the first 2 months.ConclusionThis interventional study provides Class I evidence that oral quinacrine at 300 mg per day does not improve 2-month survival of patients with sCJD, compared with placebo. Importantly, this study shows that double-blinded, placebo-controlled, randomized treatment trials are possible in prion disease. Furthermore, the quantitative data collected on the course of sCJD will be useful for future trials.Classification of evidenceThis study provides Class I evidence that quinacrine does not improve survival for people with sCJD when given orally at a dose of 300 mg per day for 2 months.
Project description:The familial or genetic Creutzfeldt-Jakob disease (fCJD or gCJD) is the inherent form of human prion diseases, which accounts for approximately 10-15% of human prion diseases that are caused by mutations of the prion protein gene (PRNP). In this study, the global expression patterns of the parietal cortex from a patient with G114V gCJD were comparatively analyzed with the normal controls by using a commercial human genome expression chip. Totally 8774 genes showed differential expression, among them 2769 genes were upregulated and 6005 ones were downregulated. The reliability of the results was confirmed by the real-time RT-PCR assays for several specific genes. The most differentially expressed genes involved in the functions of regulation of transcription, ion transport, transcription, cell adhesion, signal transduction. The gene associated with gliosis was upregulated and the genes marked for neurons were downregulated, while the transcription of PRNP gene maintained unchanged. 169 different pathways showed significantly changed in the brain of G114V gCJD. The most significantly regulated pathways included that of Alzheimer’s and Parkinson’s disease, oxidative phosphorylation, regulation of actin cytoskeleton, MAPK signaling pathway and proteasome, which were described in prion diseases previously. In addition, some rarely addressed pathways in prion diseases, such as axon guidance, gap junction and purine metabolism, were also significantly changed in G114V gCJD. The transcriptional situations of the most genes in the top ten changed pathways were down-regulated. The extensive reductions of gene expressions in G114V gCJD showed the comparable profiles with sporadic CJD. The data here raised the useful clues for understanding the pathogenesis of the disease and selecting the potential biomarkers for diagnostic and therapeutic tools.