Evan Udine, United States of America
Mount Sinai NeuroscienceAuthor Of 2 Presentations
TRANSCRIPTIONAL AND PROTEOMIC PROFILING OF THE PERIPHERAL INNATE IMMUNE SYSTEM IN ALZHEIMER’S AND PARKINSON’S DISEASES
Abstract
Aims
Recent genetic studies demonstrate the alteration of the innate immune system in neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), whereas the functional alterations and mechanisms are not really understood. We, therefore, hypothesize that AD and PD susceptibility genes modulate disease risk by dysregulation of gene expression networks and cellular function within the innate immune cells.
Methods
To address this question, we have generated a large scale dataset of genomic, bulk and single cell transcriptomic and proteomic of human derived CD14+ monocytes from disease and healthy donors. Using this dataset composed of over 500 human monocytes, we are performing integrative analysis using disease-phenotype, expression QTL, network analysis, and functional validation.
Results
Results generated to this point show profound transcriptional alterations in myeloid cells during neurodegeneration. Some key findings are that PD derived monocytes show an upregulation of mitochondrial signature, specifically oxidative phosphorylation genes, and a downregulation of proteo-lysosomal pathway, among others. The mitochondrial signature seems to be cell type specific, as directionality is flipped when compared to human microglia and macrophages. Moreover, the single cell resolution reveals that PD and AD associated genes are highly enriched in the intermediate/non-classical monocyte subclusters. Finally, the integration of expression with genetics, show how a high number of GWAS risk variants modulates gene expression in peripheral monocytes.
Conclusions
Our work shows that peripheral immune cells derived from AD/PD patients show profound dysregulation being the intermediate/non-classical subclusters key in pathology. This dataset will serve as a useful resource for further mechanistic studies and biomarker discovery.
TRANSCRIPTOMIC ANALYSIS OF CD14+ MONOCYTES IN PD PATIENTS AND WITH GBA MUTATIONS AND NON-MANIFESTING CARRIERS
Abstract
Aims
Mutations of GBA(encoding for glucocerebrosidase, GCase) represent the major genetic risk factors for Parkinson’s disease (PD). Modifiers responsible for phenoconversion in manifesting carriers are still unknown. GCase is active in monocytes and macrophages and recent studies showed a role of the innate immune system in PD. We performed an integrated transcriptomic analysis of CD14+ monocytes to assess PD mechanisms associated with GBAmutations.
Methods
We enrolled a cohort of subjects with PD and controls (CTRL) with and without GBA mutations (GBA+ and GBA-). CD14+ monocytes were purified from the peripheral blood and RNA and DNA were isolated according to standard protocol. RNA was sequenced at 60M reads per sample (Illumina HiSeq 2500). Genotyping was performed (Illumina Global Screening Array, ~700K SNPs).
Results
Data from a cohort of 56 PD-GBA-, 23 PD-GBA+, 66 CTRL-GBA-, and 13 CTRL-GBA+ were analyzed. Differential expression profiles with nested manually designed interaction model showed an enrichment of pathways related to immune response, exocytosis and RNA processing in manifesting vs non manifesting GBA carriers, and of alpha-synuclein and amyloid related genes in PD-GBA+ vs PD-GBA-. The study of genetic outliers (as assessed with the tool OUTRIDER) showed enrichment of genes related to autophagy and exocytosis in PD-GBA+ group.
Conclusions
Our data suggests that CD14+ monocytes are differently activated in manifesting and non-manifesting GBAcarriers and deregulated pathways are relevant for PD pathogenesis. Thus the study of these cells in the context of GBA-PD can open the way to the discovery of disease modifiers and possible biomarkers.