Biology subjects

Young-Pearse, T.

Publications and source records attributed to Young-Pearse, T..

3 recordsLinked to original sources

bioRxiv2017

A molecular network of the aging brain implicates INPPL1 and PLXNB1 in Alzheimer’s disease

The fact that only symptomatic therapies of small effect are available for Alzheimers disease (AD) today highlights the need for new therapeutic targets with which to prevent a major contributor to aging-related cognitive decline. Here, we report the construction and validation of a molecular network of the aging human frontal cortex. Using RNA sequence data from 478 individuals, we first identify the role of modules of coexpressed genes, and then confirm them in independent AD datasets. Then, we prioritize influential genes in AD-related modules and test our predictions in human model systems. We functionally validate two putative regulator genes in human astrocytes: INPPL1 and PLXNB1, whose activity in AD may be related to semaphorin signalling and type II diabetes, which have both been implicated in AD. This arc of network identification followed by statistical and experimental validation provides specific new targets for therapeutic development and illustrates a network approach to a complex disease.\n\nOne sentence summaryMolecular network analysis of RNA sequencing data from the aging human cortex identifies new Alzheimers and cognitive decline genes.

systems biology↗

bioRxiv2017

Integrative analyses of splicing in the aging brain: role in susceptibility to Alzheimer’s Disease

We use deep sequencing to identify sources of variation in mRNA splicing in the dorsolateral prefrontal cortex (DLFPC) of 450 subjects from two prospective cohort studies of aging. Hundreds of aberrant pre-mRNA splicing events are reproducibly associated with Alzheimers Disease (AD). We also generate a catalog of splicing quantitative trait loci (sQTL) effects in the human cortex: splicing of 3,198 genes is influenced by genetic variation. sQTLs are enriched among those variants influencing DNA methylation and histone acetylation. In assessing known AD loci, we report that altered splicing is the mechanism for the effects of the PICALM, CLU, and PTK2B susceptibility alleles. Further, we leverage our sQTL catalog to identify genes whose aberrant splicing is associated with AD and mediated by genetics. This transcriptome-wide association study identified 21 genes with significant associations, many of which are found in AD GWAS loci, but 8 are in novel AD loci, including FUS, which is a known amyotrophic lateral sclerosis (ALS) gene. This highlights an intriguing shared genetic architecture that is further elaborated by the convergence of old and new AD genes in autophagy-lysosomal-related pathways already implicated in AD and other neurodegenerative diseases. Overall, this study of the aging brains transcriptome provides evidence that dysregulation of mRNA splicing is a feature of AD and is, in some genetically-driven cases, causal.

genomics↗

bioRxiv2017

Human brain-derived Aβ oligomers bind to synapses and disrupt synaptic activity in a manner that requires APP

Compelling genetic evidence links the amyloid precursor protein (APP) to Alzheimers disease (AD), and several theories have been advanced to explain the involvement of APP in AD. A leading hypothesis proposes that a small amphipathic fragment of APP, the amyloid {beta}-protein (A{beta}), self-associates to form soluble aggregates which impair synaptic and network activity. Here, we report on the plasticity-disrupting effects of A{beta} isolated from AD brain and the requirement of APP for these effects. We show that A{beta}-containing AD brain extracts block hippocampal long-term potentiation (LTP), augment glutamate release probability and disrupt the excitation/inhibition balance. Notably, these effects are associated with A{beta} localizing to synapses, and genetic ablation of APP prevents both A{beta} binding and A{beta}-mediated synaptic dysfunctions. These findings indicate a role for APP in AD pathogenesis beyond the generation of A{beta} and suggest modulation of APP expression as a therapy for AD.\n\nAcknowledgmentsWe thank Dr. Tiernan T. OMalley for useful discussions and technical advice. This work was supported by grants to DMW from the National Institutes of Health (AG046275), Bright Focus, and the United States-Israel Binational Science Foundation (2013244, DMW and IS); grants to TSJ from Alzheimers Research UK and the Scottish Government (ARUK-SPG2013-1), Wellcome Trust-University of Edinburgh Institutional Strategic Support funds, and the H2020 European Research Council (ALZSYN); and to the Massachusetts Alzheimers Disease Research Center (AG05134).

neuroscience↗