Gene Expression Programs of Mouse Endothelial Cells in Kidney Development and Disease

Endothelial cells are remarkably heterogeneous in both morphology and function, and they play critical roles in the formation of multiple organ systems. In addition endothelial cell dysfunction can contribute to disease processes, including diabetic nephropathy, which is a leading cause of end stage renal disease. In this report we define the comprehensive gene expression programs of multiple types of kidney endothelial cells, and analyze the differences that distinguish them. Endothelial cells were purified from Tie2-GFP mice by cell dissociation and fluorescent activated cell sorting. Microarrays were then used to provide a global, quantitative and sensitive measure of gene expression levels. We examined renal endothelial cells from the embryo and from the adult glomerulus, cortex and medulla compartments, as well as the glomerular endothelial cells of the db/db mutant mouse, which represents a model for human diabetic nephropathy. The results identified the growth factors, receptors and transcription factors expressed by these multiple endothelial cell types. Biological processes and molecular pathways were characterized in exquisite detail. Cell type specific gene expression patterns were defined, finding novel molecular markers and providing a better understanding of compartmental distinctions. Further, analysis of enriched, evolutionarily conserved transcription factor binding sites in the promoters of co-activated genes begins to define the genetic regulatory network of renal endothelial cell formation. Finally, the gene expression differences associated with diabetic nephropathy were defined, providing a global view of both the pathogenic and protective pathways activated. These studies provide a rich resource to facilitate further investigations of endothelial cell functions in kidney development, adult compartments, and disease

The Biomphalaria glabrata DNA methylation machinery displays spatial tissue expression, is differentially active in distinct snail populations and is modulated by interactions with Schistosoma mansoni

BBSRC Grant (BB/K005448/1)Background The debilitating human disease schistosomiasis is caused by infection with schistosome parasites that maintain a complex lifecycle alternating between definitive (human) and intermediate (snail) hosts. While much is known about how the definitive host responds to schistosome infection, there is comparably less information available describing the snail?s response to infection. Methodology/Principle findings Here, using information recently revealed by sequencing of the Biomphalaria glabrata intermediate host genome, we provide evidence that the predicted core snail DNA methylation machinery components are associated with both intra-species reproduction processes and inter-species interactions. Firstly, methyl-CpG binding domain protein (Bgmbd2/3) and DNA methyltransferase 1 (Bgdnmt1) genes are transcriptionally enriched in gonadal compared to somatic tissues with 5-azacytidine (5-AzaC) treatment significantly inhibiting oviposition. Secondly, elevated levels of 5-methyl cytosine (5mC), DNA methyltransferase activity and 5mC binding in pigmented hybrid- compared to inbred (NMRI)- B. glabrata populations indicate a role for the snail?s DNA methylation machinery in maintaining hybrid vigour or heterosis. Thirdly, locus-specific detection of 5mC by bisulfite (BS)-PCR revealed 5mC within an exonic region of a housekeeping protein-coding gene (Bg14-3-3), supporting previous in silico predictions and whole genome BS-Seq analysis of this species? genome. Finally, we provide preliminary evidence for parasite-mediated host epigenetic reprogramming in the schistosome/snail system, as demonstrated by the increase in Bgdnmt1 and Bgmbd2/3 transcript abundance following Bge (B. glabrata embryonic cell line) exposure to parasite larval transformation products (LTP). Conclusions/Significance The presence of a functional DNA methylation machinery in B. glabrata as well as the modulation of these gene products in response to schistosome products, suggests a vital role for DNA methylation during snail development/oviposition and parasite interactions. Further deciphering the role of this epigenetic process during Biomphalaria/Schistosoma co-evolutionary biology may reveal key factors associated with disease transmission and, moreover, enable the discovery of novel lifecycle intervention strategiespublishersversionPeer reviewe

Clonally expanded mitochondrial DNA deletions within the choroid plexus in multiple sclerosis

OBJECTIVE: Mitochondrial DNA deletions (Δ-mtDNA) are implicated in the pathogenesis of multiple sclerosis (MS), Parkinson’s disease (PD), Alzheimer’s disease (AD) and ageing. Given the diffuse nature of inflammation in MS, aim of this study was to determine whether Δ-mtDNA caused respiratory deficient cells in excess of age within choroid plexus (CP) and ongoing mutagenesis or clonal expansion accounted for the respiratory deficiency in MS. METHODS: Respiratory chain complex IV and complex II activity was determined sequentially using histochemistry. Δ-mtDNA were characterized using real time PCR, long range PCR, sequencing and single molecule PCR. Sources of reactive oxygen and nitrogen species (RONS) were explored using immunohistochemistry. RESULTS: Respiratory deficient cells (lacking complex IV and with intact complex II activity) within CP epithelium were in excess of age in MS, PD and AD. Subunit-I of complex IV was lacking to a greater extent in MS than controls. Percentage of respiratory deficient cells harboring >50% heteroplasmy level of Δ-mtDNA was significantly greater in MS than PD, AD and controls. Long range PCR and sequencing confirmed Δ-mtDNA. Single molecule PCR identified clonally expanded Δ-mtDNA in MS, despite an increase in sources of RONS. INTERPRETATION: Our findings establish clonal expansion of Δ-mtDNA causing respiratory deficiency in MS and the extraparenchymal intracranial location indicated the potential to involve multiple cell types. Understanding factors that influence clonal expansion of Δ-mtDNA, a molecular link between inflammation and delayed cellular energy failure, may identify potential therapeutic targets for progressive forms of MS as well as other neurodegenerative disorders

Abrasive wear behavior of TiC-strengthened eutectic high chromium cast iron composites

202208 bcchOthersGuangzhou International Science & Technology Cooperation ProgramPublished24 month

Prelithiation strategies for silicon-based anode in high energy density lithium-ion battery

202405 bcrcVersion of RecordOthersGuangdong Basic and Applied Basic Research FoundationShenzhen Science and TechnologyTsinghua Shenzhen International Graduate SchoolPublishedC