Project description:The healthy human brain is a mosaic of varied genomes. Long interspersed element-1 (LINE-1 or L1) retrotransposition is known to create mosaicism by inserting L1 sequences into new locations of somatic cell genomes. Using a machine learning-based, single-cell sequencing approach, we discovered that somatic L1-associated variants (SLAVs) are composed of two classes: L1 retrotransposition insertions and retrotransposition-independent L1-associated variants. We demonstrate that a subset of SLAVs comprises somatic deletions generated by L1 endonuclease cutting activity. Retrotransposition-independent rearrangements in inherited L1s resulted in the deletion of proximal genomic regions. These rearrangements were resolved by microhomology-mediated repair, which suggests that L1-associated genomic regions are hotspots for somatic copy number variants in the brain and therefore a heritable genetic contributor to somatic mosaicism. We demonstrate that SLAVs are present in crucial neural genes, such as DLG2 (also called PSD93), and affect 44-63% of cells of the cells in the healthy brain.
Project description:The hippocampus is a primary region affected in Alzheimer’s disease (AD). Because AD postmortem brain tissue is not available prior to symptomatic stage, we lack understanding of early cellular pathogenic mechanisms. To address this issue, we examined the cellular origin and progression of AD pathogenesis in patient-based model systems including iPSC-derived brain cells transplanted into the mouse brain hippocampus, as well as human post-mortem hippocampal tissues. Our data showcase patient-based models to study the cellular origin, progression, and prion-like spread of AD pathogenesis.
Project description:RNA-Seq was performed in post-mortem SCA1 cerebellum at the end stage of the disease and an age/sex-matched control tissue from a healthy individual.
Project description:This experiment analyzes the mirnome of 16 retina samples and 2 Retinal Pigment Epithelium (RPE)/choroid from non-visually impaired post-mortem donors, by using smallRNAseq on a Illumina platform. The aim was to establish the catalogue of normal retina-expressed miRNAs, determine their relative abundance, and identify miRNA variants (isomiRs).
Project description:Our understanding of heart failure (HF) has been provided by indirect surrogates, such as post-mortem histology, cardiovascular imaging, and molecular characterisation in vivo and in vitro, rather than directly in pre-mortem human cardiac tissue. Using our heart bank of pre-mortem hearts procured according to the most stringent protocols, we examined ischemic (ICM) and dilated cardiomyopathy (DCM) -- the most common causes of HF and leading causes of cardiac transplantation1. We performed unbiased, comprehensive, paired proteomic and metabolomic analysis of 51 left ventricular (LV) samples from 44 cryopreserved pre-mortem human ICM and DCM hearts, including age-matched, healthy, histopathologically-normal donor controls of both genders for comparison. Data integration via pathway and correlation network analysis revealed overlapping and divergent disease pathways in ICM and DCM, and, strikingly, precise sex-specific differences within each disease that unveil the interaction of gender with HF. Identified core functional nodes in each disease may serve as novel therapeutic targets, and we provide all proteomic and metabolomic results via an interactive online repository (https://mengboli.shinyapps.io/heartomics/) as a publicly available resource.
Project description:Our understanding of heart failure (HF) has been provided by indirect surrogates, such as post-mortem histology, cardiovascular imaging, and molecular characterisation in vivo and in vitro, rather than directly in pre-mortem human cardiac tissue. Using our heart bank of pre-mortem hearts procured according to the most stringent protocols, we examined ischemic (ICM) and dilated cardiomyopathy (DCM) -- the most common causes of HF and leading causes of cardiac transplantation1. We performed unbiased, comprehensive, paired proteomic and metabolomic analysis of 51 left ventricular (LV) samples from 44 cryopreserved pre-mortem human ICM and DCM hearts, including age-matched, healthy, histopathologically-normal donor controls of both genders for comparison. Data integration via pathway and correlation network analysis revealed overlapping and divergent disease pathways in ICM and DCM, and, strikingly, precise sex-specific differences within each disease that unveil the interaction of gender with HF. Identified core functional nodes in each disease may serve as novel therapeutic targets, and we provide all proteomic and metabolomic results via an interactive online repository (https://mengboli.shinyapps.io/heartomics/) as a publicly available resource.
Project description:Cap analysis of gene expression (CAGE) and massive parallel sequencing were used to profile the promoterome of aged human brains from five regions, namely: caudate, frontal cortex, hippocampus, putamen and temporal cortex. 25 RNA libraries from post-mortem brain tissue (five caudate, five frontal, 5 hippocampus, 5 putamen, five temporal RNA libraries from seven individuals) were processed using CAGE protocol and CAGE tags derived from the 25 libraries were sequenced with Illumina.