Brain Cell Type-Specific Enhancer-Promoter Connectivity Maps and Disease Risk Association

These studies map the epigenetic landscape of microglia, neurons, astrocytes and oligodendrocytes. The initial study compared acutely isolated microglia to cultured microglia from the same donors, to identify changes that occur when microglia are removed from the brain microenvironment. In collaboration with the Rady Children's Hospital, we obtained brain tissue samples from pediatric patients representing putative normal tissue resected to gain access to brain tumors as well as tissue resected to remove epileptic foci. We assayed microglia isolated from these samples using RNA-seq, ATAC-seq and ChIP-seq for PU.1, H3K4me2, and H3K27ac. For patients from whom a sufficient cell number was obtained, we additionally cultured their microglia for up to 7 days and subjected these to the same suite of assays. In a follow-up study, we obtained brain tissue from a comparable cohort of pediatric epilepsy patients from Rady Children's Hospital. We isolated nuclei from microglia, neurons, astrocytes and oligodendrocytes, and assayed for ATAC-seq, ChIP-seq for H3K4me3, and H3K27ac, and PLAC-seq (Proximity Ligated ChIP-seq). We isolated microglia from human fetal and postnatal sample and assayed for bulk RNA-seq, bulk ATAC-seq, bulk H3K27ac ChIP-seq, single-cell RNA-seq (scRNA-seq) and single-cell ATAC-seq. For these studies, human microglia are defined by signature genes/proteins, such as P2RY12, SALL1, and CX3CR1.]]>
Patients under the age of 19 undergoing neurosurgical procedure at Rady Children's Hospital in which tissue was resected in excess of what was required for pathological diagnosis. Diagnosis includes: Patients with intractable focal epilepsy having failed multiple antiepileptics undergoing epilepsy focus resection. Patients with a variety of brain tumors undergoing radical tumor resection. Exclusion criteria: Parents declined consent. Brain tumor biopsy only. Tissue sufficient only for pathological diagnosis. ]]>
Patients have been enrolled from March 2015 to present. The study is ongoing. ]]>