Project description:Antibiotic resistance genes (ARGs) and virulence genes (VGs) associated with bacterial pathogens are of great concern in WWTPs, while current knowledge of their profiles and co-occurrence patterns in different time intervals is barely sufficient. Moreover, the impacts of treatment process on ARG/VGs diversity also remain clear. To this end, this study was launched to address the differences of the ARG/VGs diversity between an oxidation ditch (OD) and an membrane bioreactor (MBR) and the co-occurrence patterns in different time intervals using a functional gene array-GeoChip.
Project description:Subset heterogeneity of the mononuclear phagocyte system (MPS) is controlled by defined transcriptional networks and programs; however, the dynamic establishment of programs that control broad, orchestrated expression of transcription factors (TFs) during the progression of monocyte-into-phagocyte (MP) differentiation remains largely unexplored. By combining chromatin immunoprecipitation assays with gene expression profiling (ChIP-on-Chip), we show the extensive trimethylation of histone H3 lysine 4 (H3K4me3) as well as histone H3 lysine 27 (H3K27me3) occupancy with broad footprints at the promoters of MP differentiation-related TFs, such as HOXA and FOXO genes, KLF4, IRF8 and others. The rapid repression of HOXA genes was closely associated with the MP differentiation program. H3K4me3 participates in regulating HOXA genes at mild and terminal differentiation periods, while H3K27me3 maintains low-level expression of HOXA genes at phagocytic maintenance periods. Furthermore, the reprogramming of H3K27me3 plays a major role in the up-regulation of KLF4 and FOXO genes during MP differentiation. Importantly, the pharmacological inhibition of H3K4me3 and/or H3K27me3 strikingly promotes the differentiation programs of THP-1 and K562 cells as well as primary bone marrow-derived progenitors. Together, these findings elucidate mechanisms crucial to the dynamic establishment of epigenetic memory, which is central to the maintenance of the MP differentiation blockade. THP-1 cells: control and 50 ng/ml PMA (Phorbol 12-myristate 13-acetate) treated for 72 h were collected for H3K4me3 and H3K27me3 ChIP-on-chip.
Project description:Freshwater environments such as rivers receive effluent discharges from wastewater treatment plants, representing a potential hotspot for antibiotic resistance genes (ARGs). These effluents also contain low levels of different antimicrobials including biocides and antibiotics such as sulfonamides that can be frequently detected in rivers. The impact of such exposure on ARG prevalence and microbial diversity of riverine environment is unknown, so the aim of this study was to investigate the release of a sub-lethal concentration (<4 g L-1) of the sulfonamide compound sulfamethoxazole (SMX) on the river bacterial microbiome using a microflume system. This system was a semi-natural in-vitro microflume using river water (30 L) and sediment, with circulation to mimic river flow. A combination of ‘omics’ approaches were conducted to study the impact of SMX exposure on the microbiomes within the microflumes. Metaproteomics did not show differences in ARGs expression with SMX exposure in water.
Project description:We identified ARGs in a genome-wide manner, in fly brains as well as in sorted neurons; they included dopaminergic neurons (DA) and a subset of circadian-related neurons (PDF+ neurons).
Project description:The cerebral cortex is a highly organized structure whose development depends on different progenitor cell types. These give rise to post-mitotic neurons that migrate across the developing cortical wall to their final positions in the cortical plate. Apical radial glia cells (aRGs) are the main progenitor type in early corticogenesis, responsible for the production of other progenitors, and regulating the final neuronal output. Abnormal behavior of aRG can severely impact corticogenesis resulting in cortical malformations. Mutations in the microtubule associated protein Eml1 lead to severe subcortical heterotopia, characterized by the presence of aberrantly located neurons beneath the normotopic cortex. Mutations in EML1/Eml1 have been reported in three families presenting severe atypical heterotopia, as well as in the Heterotopic cortex ‘HeCo’ spontaneous mouse mutant. In the latter, ectopically cycling aRGs were found cycling outside their normal proliferative ventricular zone (VZ) from early stages of corticogenesis (Croquelois et al., 2009, Kielar et al., 2014, Shaheen et al., 2017). Ectopic aRGs are likely to be responsible for the formation of the heterotopia. It is thus crucial to understand the role of Eml1 in aRGs to elucidate the physiological and pathological mechanisms causing aRGs to leave the VZ. The role of Eml1 in aRGs remains vastly unexplored. We have thus performed mass spectrometry with embryonic cortex lysates (E13.5) to shed light on the intracellular pathways and molecular mechanisms in which Eml1 could be involved. This data combined with other cell biology and biochemistry approaches will contribute to understand the role of this heterotopia protein at early stages of development.
Project description:The goal of this experiment was to define gene expression patterns of two mouse retinal neuron subsets that express the Thy1-mitoCFP-P (MP) transgene. The two populations expressing the MP transgene are: 1) non-GABAergic, non-glycinergic amacrine cells; and 2) a subset of OFF-type bipolar cells. We used the VC1.1 monoclonal antibody, which labels amacrine cells (ACs) but not bipolar cells, to separately purify the AC and bipolar populations that express the MP transgene. Two biological replicates, originating from different litters, were collected for each sample. RNA was extracted from sorted cells and prepared for hybridization to Affymetrix microarrays.
Project description:Cells of the vascular system release spherical vesicles, called microparticles (MP), in the size range of 0.1-1μm induced by a variety of stress factors resulting in variable MP concentrations between health and disease. Furthermore, MP have intercellular communication/signaling properties and interfere with inflammation and coagulation pathways. Today’s most used analytical technology for MP characterization, flow cytometry, is lacking sensitivity and specificity, which might have led to the publication of contradicting results in the past. We propose the use of nano-liquid chromatography coupled to two-stage mass spectrometry as a non-biased tool for quantitative MP proteome analysis. Using aliquots of 250 μL platelet-free plasma (PFP) from one individual donor, we achieved excellent inter-assay CV’s of 2.7 ± 1.7% (mean ± 1 S.D.) on individual peptide intensities across 27 data-dependent nanoLC-MS/MS runs performed over a period of 3.5 months. With quantitative proteomics, we show that MP composition between twelve volunteers were remarkably stable. MP protein composition is clearly distinguishable from whole cell lysates and we propose that this trait should be used as a quality criterion of MP purity. Furthermore, MP were damaged by freezing PFP. The damage was articulated by a loss of cytoplasm proteins, encompassing a specific set of proteins involved in regulating dynamic structures of the cytoskeleton, and thrombin activation leading to MP clotting. On the other hand, plasma membrane protein composition (cell markers) was not affected. Finally, we show that multiplexed data-independent acquisition can be used for relative quantification of target proteins using Skyline software.
Project description:We identified ARGs in a genome-wide manner, in fly brains as well as in sorted neurons; they included dopaminergic neurons (DA) and a subset of circadian-related neurons (PDF+ neurons).
Project description:We identified ARGs in a genome-wide manner, in fly brains as well as in sorted neurons; they included dopaminergic neurons (DA) and a subset of circadian-related neurons (PDF+ neurons).