Single-Cell Genomic and Transcriptomic Analysis of the Aging Human Brain

We studied human brain aging using single-cell whole genome sequencing and single-nucleus RNA sequencing of the pre-frontal cortex from 19 donors ranging in age from 0.4 years to 104 years. All donors were free of neuropathology and none received a clinical neurological diagnosis prior to death. snRNA-seq libraries were prepared in batches that always included old and young donors to mitigate batch effects in the preparations. Neurons for single-cell WGS were collected from the same tissue region as the snRNA-seq for each donor but represent independent cells. Multiplexed error-robust fluorescent in-situ hybridization (MERFISH) data was also collected from pre-frontal cortex samples of a subset of the 19 donors. Transcriptomic results identified infant-specific cell clusters, and common-down regulation of cell-essential genes involved in ribosomes, transport, homeostasis and metabolism during aging, across all cell types. scWGS identified two-age associated mutational signatures, as well as gene-length and expression-level dependent somatic mutation rates in neurons. Raw sequencing data in fastq format for single-nucleus RNA-seq and single-cell DNA-seq, as well as cell and gene count matrix, transcript metadata, and cell metadata for MERFISH will be available in dbGaP.]]>
All donors were neurologically normal at the time of death and were free of neuropathology that meets diagnostic criteria for a neurodegenerative disease. Donors that met these criteria were chosen to represent the spectrum of human aging from infant through centenarian. Our protocols for single neuron whole genome sequencing and single-nucleus RNA sequencing require using frozen brain tissue, so the ability to obtain both high quality DNA and RNA sequencing also determined which donors were included in the study.]]>