Synapse-centered novel omics targets in Alzheimer's disease - miRNA
Synapse dysfunction is an early event of Alzheimer's disease (AD). It is caused by multiple cellular and pathological factors such as Amyloid beta, p-tau, inflammation, and aging. However, the exact molecular mechanism of synapse dysfunction in AD is largely unknown. Therefore, to understand the molecular basis of synapse dysfunction in AD, we conducted a high throughput multi-omics analysis of the synaptosome fraction in postmortem brain samples from AD patients and cognitively normal individuals. First, microRNA and mRNA HiSeq analysis were performed on the synaptosomes extracted from the postmortem brains of unaffected control (UC) individuals and AD patients. Next, we conducted the mass spectrometry analysis of synaptosomal proteins in the same sample group of HC and AD. The transcriptomic and proteomic profiling of synaptosome showed the significant deregulation of miRNA, mRNA and protein signatures in AD vs HC.  Further, we used an integrated transcriptomic and proteomic approach to understand the molecular interactions of deregulated synapse miRNAs, mRNAs, and proteins in the same samples of AD and HC. Multi-omics integration analysis of synapse miRNAs-mRNAs-proteins revealed the involvement of omics targets in several biological processes and molecular functions such as signal transduction, protein binding, GABAergic synapse, and synaptic vesicle cycle, etc. Our study unveiled synapse-centered novel omics candidates that could be potential therapeutic targets to restore synapse dysfunction in AD. Overall design: We used postmortem brains from AD (n=42) and controls (n=14). Synaptosomes were isolated from AD and control brains. Further, total RNA were isolated from the synaptosome and subjected to miRNA and mRNA HiSeq analysis.