Project description:Human cerebrospinal fluid was collected from patients diagnosed with neurodegenerative diseases including multiple system atrophy (n=28), Parkinson’s disease (n=40), dementia with Lewy bodies (n=20), progressive supranuclear palsy (n=39) and from controls (n=17) in order to perform a comparative quantitative proteome profiling of cerebrospinal fluids from the five groups.
Project description:Progressive Supranuclear palsy (PSP) is a 4-repeat (4-R) tauopathy. We hypothesized that the molecular diversity of tau could explain the heterogeneity seen in PSP disease progression. To test this hypothesis, we performed an extensive biochemical characterisation of the high molecular weight tau species (HMW-Tau) in 20 different brain regions of 25 PSP patients. To identify factors that contribute to these differences, we performed proteomic analysis that revealed key mechanistic pathways, in particular those involving the immune system, that defined patients demonstrating high and low tau seeding capacity.
Project description:Progressive supranuclear palsy (PSP) is a neurodegenerative parkinsonian disorder. This study using CSF samples of PSP patients is a follow-up study to discover biomarkers related to the previous PSP brain results. This study is the first-ever attempt at an in-depth global proteomic study using more than 100 CSF samples for PSP study. In this study, we used the 11-plex isobaric tandem-mass-tag (TMT) technology for more accurate and sensitive quantification of CSF proteins and analyzed them using Orbitrap Fusion Lumos mass spectrometry on 40 PSP and 40 PD patients as well as 40 HC individuals CSF samples for the discovery experiment. These candidate biomarkers discovered in this study will pave the way for the development of reliable PSP biomarkers.
Project description:Progressive Supranuclear Palsy (PSP) is a clinically heterogeneous 4-repeat (4R)-tauopathy marked by variable progression and phenotypic diversity. We examined the distribution of high-molecular-weight tau (HMW-tau) species and 4R-tau seeding capacity across 25 PSP cases and 20 brain regions. HMW-tau levels varied regionally, with the temporal and motor cortices exhibiting the highest abundance. Using size-exclusion chromatography (SEC) and 4R-tau seed amplification assays (SAAs), we identified that HMW-tau fractions exhibit the greatest seeding activity. Proteomic and spatial transcriptomic analyses of the primary motor cortex revealed dysregulated adaptive immunity and metabolic pathways in high-seeder cases. Neuropathological clustering confirmed distinct profiles associated with tau seeding activity. These findings suggest that evaluating tau seeding capacity may offer valuable insights into the heterogeneity of PSP and its underlying molecular drivers.
Project description:Progressive supranuclear palsy (PSP) is a neurodegenerative tauopathy described as a syndrome of postural instability, supranuclear vertical gaze palsy, dysarthria, dystonic rigidity of the neck and trunk, dementia, and pseudobulbar palsy. The clinical diagnosis of PSP is often difficult because there are no established biomarkers, and diagnosis is currently based on clinical and imaging findings. Furthermore, the etiology and pathogenesis of PSP remain unknown. Dysregulation of microRNAs (miRNAs/miRs) has been reported to serve an important role in neurodegenerative diseases. However, the miRNA profiles of patients with PSP are rarely reported. The present study aimed to examine cerebrospinal fluid miRNAs, which are considered to be more sensitive indicators of changes in the brain, to elucidate the pathophysiology of PSP and to establish specific biomarkers for diagnosis. The present study used a microarray chip containing 2,632 miRNAs to examine cerebrospinal fluid miRNA expression levels in 11 patients with PSP aged 68‑82 years. A total of 8 age‑ and sex‑matched controls were also included. A total of 38 miRNAs were significantly upregulated and one miRNA was significantly downregulated in the cerebrospinal fluid of patients with PSP. The patients were divided into two groups based on disease stage (early onset and advanced), and changes in miRNA expression were examined. The miRNAs that were most significantly upregulated or downregulated in the early onset group were miR‑204‑3p, miR‑873‑3p and miR‑6840‑5p. The target genes of these miRNAs were associated with molecules related to the ubiquitin‑proteasome system and autophagy pathway. Furthermore, these miRNAs were found to target genes that have been reported to have epigenetic changes following an epigenome‑wide association study of brain tissues of patients with PSP. This suggested that these miRNAs and genes may have some involvement in the pathogenesis of PSP. However, the sample size of the present study was small; therefore, a greater number of patients with PSP should be examined in future studies.