Project description:Separating lipid-carrying particles from body fluids is challenging and complicates studies of extracellular vesicles (EV) and lipoprotein particles (LPP) as disease biomarkers. In this study, we assess the biomolecular composition and dynamics of systemically circulating matched EV and LPP by analyzing serial blood plasma samples from breast cancer, ovarian cancer and HIV patients (n=36). Particles were separated through combined size-exclusion chromatography (SEC) and equilibrium density gradient centrifugation. After the analytical validity of our method is demonstrated, we reveal that EV carry a unique, dynamic and condition-dependent protein composition and RNA profile, which is not directly measurable in LPP extracts and total blood plasma, respectively. Our study extends the knowledge on the compositional nature of the EV protein corona and provides a catalog of proteins associated with systemically circulating EV and LPP. We anticipate that this research will steer the further development of EV-based biomarkers to detect and monitor disease.
Project description:The aim of this study was to compare the effects of cocoa butter and safflower oil on hepatic transcript profiles, lipid metabolism and insulin sensitivity in healthy rats. Cocoa butter-based high-fat feeding for three days did not affect plasma total triglyceride (TG) levels or TG-rich VLDL particles or hepatic insulin sensitivity, but changes in hepatic gene expression were induced that might lead to increased lipid synthesis, lipotoxicity, inflammation and insulin resistance if maintained. Safflower oil increased hepatic β-oxidation, was beneficial in terms of circulating TG-rich VLDL particles, but led to reduced hepatic insulin sensitivity. The effects of safflower oil on hepatic gene expression were partly overlapping with those exerted by cocoa butter, but fewer transcripts from anabolic pathways were altered. Increased hepatic cholesterol levels and increased expression of hepatic CYP7A1 and ABCG5 mRNA, important gene products in bile acid production and cholesterol excretion, were specific effects elicited by safflower oil only. Common effects on gene expression included increased levels of p8, DIG-1 IGFBP-1 and FGF21, and reduced levels of SCD-1 and SCD-2. This indicates that a lipid-induced program for hepatic lipid disposal and cell survival was induced by three days of high-fat feeding, independent on the lipid source. Based on the results, we speculate that hepatic TG infiltration leads to reduced expression of SCD-1, which might mediate either neutral, beneficial or unfavourable effects on hepatic metabolism upon high-fat feeding, depending on which fatty acids were provided by the diet. Keywords: Hepatic gene expression Two-condition experiment. Biological replicates: 4 male rat livers from rats on a standard diet, 4 male rat livers from rats on a cocoa butter diet, 4 male rat livers from rats on a high-fat (safflower oil) diet. One replicate per array.
Project description:Heat shock rapidly induces expression of a small set of genes while globally repressing transcription, making it an attractive system for studying alterations in the chromatin landscape that accompany changes in gene regulation. We have characterized these changes using low-salt extraction of intact micrococcal nuclease (MNase)-treated Drosophila S2 cell nuclei to determine the active nucleosomal and subnucleosomal chromatin landscapes. The low-salt-soluble fraction corresponds to classical "active" chromatin and includes distinct size fractions of MNase-protected particles that can be precisely mapped by paired-end sequencing. After heat shock, the distribution of low-salt-soluble nucleosomes showed an overall reduction over gene bodies, consistent with down-regulation of transcription. No global changes were detected in the subnucleosomal landscape upstream of transcriptional start sites, however, we observed a genome-wide reduction of paused RNA Polymerase II from the active chromatin fraction. Furthermore, nucleosome turnover decreased within gene bodies in a pattern similar to that observed when transcription elongation was artificially inhibited. These observations suggest that reduced Pol II affinity and processivity is the dominant nuclear mechanism for genome-wide repression during heat shock. Our ability to precisely map both nucleosomal and subnucleosomal particles directly from classical active chromatin extracts to assay changes in the chromatin landscape provides a simple general strategy for epigenome characterization. High-throughput sequencing (Illumina HiSeq 2000) We have characterized changes to the active nucleosomal and subnucleosomal landscape during the heat shock response in Drosophila cells by genome-wide profiling of low-salt extracted micrococcal nuclease-treated nuclei, paused RNA Polymerase II and CATCH-IT nucleosome turnover.
Project description:RNA was isolated from LNCaP-SL after 24 hours of circulating small extracellular vesicles (csEV) single dose treatment (1×10^10 particles/mL).
Project description:Specific mutations in Apolipoprotein A-I (ApoA-I) of high-density lipoprotein (HDL) are responsible for a late-onset systemic amyloidosis. Carriers do not exhibit increased cardiovascular disease risk despite reduced levels of ApoA-I/ HDL-cholesterol. To explain this paradox, we show that the HDL particle profile of L75P and L174S patients presents a higher relative abundance of the 8.4 nm vs 9.6 nm particles, and that serum from patients, as well as reconstituted 8.4 and 9.6 nm HDL particles (rHDL), possess increased capacity to catalyze cholesterol efflux from macrophages. Synchrotron radiation circular dichroism and hydrogen-deuterium exchange revealed that the variants in 8.4 nm rHDL have altered secondary structure composition and display a more flexible binding to lipids compared to their native counterpart. The reduced HDL-cholesterol levels of patients carrying ApoA-I amyloidogenic variants are thus balanced by higher proportion of small, dense HDL particles and better cholesterol efflux due to altered, region-specific protein structure dynamics.
Project description:The aim of this study was to compare the effects of cocoa butter and safflower oil on hepatic transcript profiles, lipid metabolism and insulin sensitivity in healthy rats. Cocoa butter-based high-fat feeding for three days did not affect plasma total triglyceride (TG) levels or TG-rich VLDL particles or hepatic insulin sensitivity, but changes in hepatic gene expression were induced that might lead to increased lipid synthesis, lipotoxicity, inflammation and insulin resistance if maintained. Safflower oil increased hepatic β-oxidation, was beneficial in terms of circulating TG-rich VLDL particles, but led to reduced hepatic insulin sensitivity. The effects of safflower oil on hepatic gene expression were partly overlapping with those exerted by cocoa butter, but fewer transcripts from anabolic pathways were altered. Increased hepatic cholesterol levels and increased expression of hepatic CYP7A1 and ABCG5 mRNA, important gene products in bile acid production and cholesterol excretion, were specific effects elicited by safflower oil only. Common effects on gene expression included increased levels of p8, DIG-1 IGFBP-1 and FGF21, and reduced levels of SCD-1 and SCD-2. This indicates that a lipid-induced program for hepatic lipid disposal and cell survival was induced by three days of high-fat feeding, independent on the lipid source. Based on the results, we speculate that hepatic TG infiltration leads to reduced expression of SCD-1, which might mediate either neutral, beneficial or unfavourable effects on hepatic metabolism upon high-fat feeding, depending on which fatty acids were provided by the diet. Keywords: Hepatic gene expression
Project description:Biomolecular condensates play important roles in diverse biological processes. Many viruses form biomolecular condensates which have been implicated in various functions critical for productive infection of host cells. The adenovirus L1-52/55 kilodalton protein (52K) was recently shown to form viral biomolecular condensates that coordinate viral genome packaging and capsid assembly. Although critical for packaging, we do not know how viral condensates are regulated during adenovirus infection. Here we show that phosphorylation of serine residues 28 and 75 within the N-terminal intrinsically disordered region of 52K modulates viral condensates in vitro and in cells, promoting liquid-like properties over condensate hardening. Furthermore, we demonstrate that phosphorylation of 52K promotes viral genome packaging and production of infectious progeny particles. Collectively, our findings provide insights into how viral condensate properties are regulated and maintained in a state conducive to their function in viral progeny production. In addition, our findings have implications for antiviral strategies aimed at targeting the regulation of viral biomolecular condensates to limit viral multiplication.
Project description:To systemically investigate the mechanism underlying the impact of SOX9 on lipid metabolism in NASH, we performed RNA-seq analysis in liver tissues from Sox9HKO mice and Sox9f/f mice after 6 weeks of MCD feeding.
Project description:To systemically identify the long non-coding RNAs(lncRNAs) expression profile in the liver, specifically those involved in lipid metabolism, we generated a hyperlipemia model in mice. The hyperlipemia protocol was as follows:mice post natal 4 weeks fed normal diet or subjet to 60% high fat diet for 23 weeks, the mice were immediately sacrificed for liver and plasma collection.