Blood-based high sensitivity measurements of beta-amyloid and phosphorylated tau as biomarkers of Alzheimer's disease: a focused review on recent advances

Discovery and development of clinically useful biomarkers for Alzheimer’s disease (AD) and related dementias have been the focus of recent research efforts. While cerebrospinal fluid and positron emission tomography or MRI-based neuroimaging markers have made the in vivo detection of AD pathology and its consequences possible, the high cost and invasiveness have limited their widespread use in the clinical setting. On the other hand, advances in potentially more accessible blood-based biomarkers had been impeded by lack of sensitivity in detecting changes in markers of the hallmarks of AD, including amyloid-β (Aβ) peptides and phosphorylated tau (P-tau). More recently, however, emerging technologies with superior sensitivity and specificity for measuring Aβ and P-tau have reported high concordances with AD severity. In this focused review, we describe several emerging technologies, including immunoprecipitation-mass spectrometry (IP-MS), single molecule array and Meso Scale Discovery immunoassay platforms, and appraise the current literature arising from their use to identify plaques, tangles and other AD-associated pathology. While there is potential clinical utility in adopting these technologies, we also highlight the further studies needed to establish Aβ and P-tau as blood-based biomarkers for AD, including validation with existing large sample sets, new independent cohorts from diverse backgrounds as well as population-based longitudinal studies. In conclusion, the availability of sensitive and reliable measurements of Aβ peptides and P-tau species in blood holds promise for the diagnosis, prognosis and outcome assessments in clinical trials for AD

Brain atrophy and white matter hyperintensities are independently associated with plasma neurofilament light chain in an Asian cohort of cognitively impaired patients with concomitant cerebral small vessel disease

Introduction: Plasma neurofilament light chain (NfL) is a potential biomarker for neurodegeneration in Alzheimer's disease (AD), ischemic stroke, and non-dementia cohorts with cerebral small vessel disease (CSVD). However, studies of AD in populations with high prevalence of concomitant CSVD to evaluate associations of brain atrophy, CSVD, and amyloid beta (Aβ) burden on plasma NfL are lacking. Methods: Associations were tested between plasma NfL and brain Aβ, medial temporal lobe atrophy (MTA) as well as neuroimaging features of CSVD, including white matter hyperintensities (WMH), lacunes, and cerebral microbleeds. Results: We found that participants with either MTA (defined as MTA score ≥2; neurodegeneration [N]+WMH−) or WMH (cut-off for log-transformed WMH volume at 50th percentile; N−WMH+) manifested increased plasma NfL levels. Participants with both pathologies (N+WMH+) showed the highest NfL compared to N+WMH−, N−WMH+, and N−WMH− individuals. Discussion: Plasma NfL has potential utility in stratifying individual and combined contributions of AD pathology and CSVD to cognitive impairment

Isoform‐specific upregulation of FynT kinase expression is associated with tauopathy and glial activation in Alzheimer’s disease and Lewy body dementias

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record Cumulative data suggest the involvement of Fyn tyrosine kinase in progression of Alzheimer's disease (AD). Previously, our group has shown increased immunoreactivities of the FynT isoform in AD neocortex (with no change in the alternatively spliced FynB isoform) which associated with neurofibrillary degeneration and reactive astrogliosis. Since both the aforementioned neuropathological features are also frequently found in Lewy Body dementias (LBD), we investigated potential perturbations of Fyn expression in the postmortem neocortex of patients with AD, as well as those having one of the two main subgroups of LBD: Parkinson’s disease dementia (PDD) and dementia with Lewy bodies (DLB). We found selective upregulation of FynT expression in AD, PDD and DLB which also correlated with cognitive impairment. Furthermore, increased FynT expression correlated with hallmark neuropathological lesions, soluble β-amyloid and phosphorylated tau, as well as markers of microglia and astrocyte activation. In line with the human postmortem studies, cortical FynT expression in aged mice transgenic for human P301S tau was upregulated and correlated with accumulation of aggregated phosphorylated tau as well as with microglial and astrocytic markers. Our findings point to FynT being an important mediator of disease progression in neurodegenerative dementias, likely via effects on tauopathy and neuroinflammation.National Medical Research Council, Singapor

The detector system of the Daya Bay reactor neutrino experiment

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Genome-wide profiling of alternative splicing in Alzheimer's disease

Alternative splicing is a highly regulated process which generates transcriptome and proteome diversity through the skipping or inclusion of exons within gene loci. Identification of aberrant alternative splicing associated with human diseases has become feasible with the development of new genomic technologies and powerful bioinformatics. We have previously reported genome-wide gene alterations in the neocortex of a well-characterized cohort of Alzheimer's disease (AD) patients and matched elderly controls using a commercial exon microarray platform [1]. Here, we provide detailed description of analyses aimed at identifying differential alternative splicing events associated with AD

Genome-wide profiling of alternative splicing in Alzheimer's disease

10.1016/j.gdata.2014.09.002Genomics Data2290-29

NeuroAiD (R) (MLC601) and Amyloid Precursor Protein Processing

10.1159/000346236CEREBROVASCULAR DISEASES35SUPPL.130-37United State

Overexpression of p53 in hepatocellular carcinomas: A clinicopathological and prognostic correlation

Overexpression of the p53 tumour suppressor gene is one of the most common abnormalities in primary human cancers and appears to be a result of point mutation within a highly conserved region of the gene with subsequent encoding for a mutant, more stable, protein. In this study, 71 surgically resected hepatocellular carcinomas (HCC) were examined to study the expression of the p53 gene, its relation with clinicopathological parameters and its prognostic significance. Using immunohistochemical detection for mutant p53 protein with monoclonal antibody PAb1801, p53 overexpression was found in 22 tumours (31%) but in none of the non-tumorous liver specimens. Overexpression of p53 was more frequent in tumours with poor cellular differentiation (P = 0.01), in tumours > 5 cm in diameter (P = 0.05), and in those with giant cells present (P = 0.03) and, less significantly, of massive type of Eggel's classification (P = 0.06). It did not have any significant correlation with hepatitis B or C status, background liver disease or serum α-fetoprotein levels, nor was it related to tumour invasiveness (venous permeation, direct liver invasion and tumour microsatellite formation). In addition, the presence of p53 mutant protein did not influence tumour recurrence or patients' survival rates. The data suggested that p53 mutation in HCC was associated with a later stage of oncogenesis. However, it was not apparently related to tumour invasiveness/aggressiveness and prognosis.link_to_subscribed_fulltex

Prognostic significance of pathologic features of hepatocellular carcinoma: a multivariate analysis of 278 patients

Background. In patients with hepatocellular carcinoma, surgical resection may offer a chance of cure. However, tumor recurrence is not infrequent after resection. Methods. To identify the pathologic factors that are of prognostic significance and predictive value in tumor recurrence, the authors studied 278 patients (243 men, 35 women) who had hepatectomy for hepatocellular carcinoma. Disease free and actuarial survival were correlated with 20 pathologic parameters of the resected specimens using multivariate analysis. Results. The median follow-up period was 23.6 months. The overall disease free survival rates at 1, 3 and 5 years were 42%, 23%, and 17%, respectively, and the overall actuarial survival rates for the corresponding time periods were 70%, 39%, and 28%, respectively. The results indicated that tumor encapsulation (P = 0.004) and heavy intratumor inflammatory infiltrates (P = 0.003) were independent favorable factors related to tumor recurrence. Negative resection margins (P = 0.001) and heavy intratumor inflammatory infiltrates (P = 0.003) were independent favorable factors correlated with survival. Conclusions. From this analysis, it was determined that detailed histologic examination of resected specimens of hepatocellular carcinoma is important in assessing long term prognosis and stratification of patients for treatment.link_to_OA_fulltex