Project description:Microsporidia are intracellular eukaryotic pathogens that pose a substantial threat to immunocompromised hosts. The way these pathogens manipulate host cells during infection remains poorly understood. Using a proximity biotinylation strategy we established that microsporidian EnP1 is a nucleus-targeted effector that modifies the host cell environment. EnP1's translocation to the host nucleus is meditated by nuclear localization signals (NLSs). In the nucleus, EnP1 interacts with host histone H2B. This interaction disrupts H2B monoubiquitination (H2Bub), subsequently impacting p53 expression. Crucially, this inhibition of p53 weakens its control over the downstream target gene SLC7A11, enhancing the host cell's resilience against ferroptosis during microsporidian infection. This favorable condition promotes the proliferation of microsporidia within the host cell. These findings shed light on the molecular mechanisms by which microsporidia modify their host cells to facilitate their survival.
Project description:The cellular composition of heterogeneous samples can be predicted from reference gene expression profiles that represent the homogeneous, constituent populations of the heterogeneous samples. However, existing methods fail when the reference profiles are not representative of the constituent populations. We developed PERT, a new probabilistic expression deconvolution method, to address this limitation. PERT was used to deconvolve cellular composition of variably sourced and treated heterogeneous human blood samples. Our results indicate that even after correcting batch effects, cells presenting the same cell surface antigens display different transcriptional programs when they are uncultured versus culture-derived. Given gene expression profiles of culture-derived heterogeneous samples and profiles of uncultured reference populations, PERT was able to accurately recover proportions of pure populations composing the heterogeneous samples. We anticipate that PERT will be widely applicable to expression deconvolution problems using profiles from reference populations that vary from the corresponding constituent populations in cellular state but not cellular identity. Gene expression microarray to examine transcriptome variations between uncultured and culture-deried blood cells of the same phenotype as defined by the on and off expression of antigens.
Project description:The cellular composition of heterogeneous samples can be predicted from reference gene expression profiles that represent the homogeneous, constituent populations of the heterogeneous samples. However, existing methods fail when the reference profiles are not representative of the constituent populations. We developed PERT, a new probabilistic expression deconvolution method, to address this limitation. PERT was used to deconvolve cellular composition of variably sourced and treated heterogeneous human blood samples. Our results indicate that even after correcting batch effects, cells presenting the same cell surface antigens display different transcriptional programs when they are uncultured versus culture-derived. Given gene expression profiles of culture-derived heterogeneous samples and profiles of uncultured reference populations, PERT was able to accurately recover proportions of pure populations composing the heterogeneous samples. We anticipate that PERT will be widely applicable to expression deconvolution problems using profiles from reference populations that vary from the corresponding constituent populations in cellular state but not cellular identity. Gene expression microarray to examine transcriptome variations between uncultured and culture-deried blood cells of the same phenotype as defined by the on and off expression of antigens. Fresh human umbilical cord blood-derived and serum free culture-derived colony-forming unit-monocytes (CFU-M) and megakaryocytes (MEGA) were compared respectively
Project description:The majority of fungal species prefer the 12°–30° C range and relatively few species tolerate temperatures higher than 35° C . Our understanding of the mechanisms underpinning the ability of some species to grow at higher temperatures is incomplete. Nosema ceranae is an obligate intracellular fungal parasite that infects honey bees and can cause individual mortality and contribute to colony collapse. Despite a reduced genome, this species is strikingly thermotolerant, growing optimally at the colony temperature of 35° C. In characterizing the HSR in N. ceranae, we found that this and other microsporidian species have lost the transcriptional regulator HSF and possess a reduced set of putative core HSF1-dependent HSR target genes. Despite these losses, N. ceranae demonstrates robust upregulation of the remaining HSR target genes after heat shock. In addition, thermal stress leads to alterations in genes involved in various metabolic pathways, ribosome biogenesis and translation, and DNA repair. These results provide important insight into the stress responses of microsporidia. Such new understanding will allow new comparisons with other pathogenic fungi and potentially enable discovery of novel treatment strategies for microsporidia infections affecting food production and human health.
Project description:The human liver contains multiple cell types whose epigenetic patterns are undetermined. We examined the promoter methylome of purified and uncultured hepatic stellate cells (HSCs), hepatocytes (HEPs) and liver sinusoidal endothelial cells (LSECs), by methylated DNA immunoprecipitation (MeDIP) and array hybridization. Uncultured HSCs, LSECs and Heps show ~7000-8000 methylated promoters, with 60-70% similarity between all cell types. GO analysis for commonly methylated genes reveals involvement in germ cell development, segregating germ-line from somatic lineage methylation. HSCs, LSECs and HEPs also contain ~500-1000 uniquely methylated promoters; these are implicated in signaling and biosynthetic processes (HSCs), lipid transport and metabolism (LSECs), and chromatin assembly (HEPs). The promoter methylome of culture-activated HSCs deviates from that of their uncultured (quiescent) counterparts. HSC culture-induced activation also enhances methylation differences between individual donors; however this does not necessarily relate to changes in gene expression. HSc activation results in a net gain of promoter DNA methylation, despite the demethylation and de novo methylation of thousands of promoters. Our data provide to our knowledge the first genome-wide maps of promoter DNA methylation in human purified and uncultured liver cell types. Although methylation profiles are largely similar between HSCs, LSECs and hepatocytes, the detection of cell type-specific methylation patterns suggests a differential epigenetic programming of these cell types in the liver.
Project description:The human liver contains multiple cell types whose epigenetic patterns are undetermined. We examined the promoter methylome of purified and uncultured hepatic stellate cells (HSCs), hepatocytes (HEPs) and liver sinusoidal endothelial cells (LSECs), by methylated DNA immunoprecipitation (MeDIP) and array hybridization. Uncultured HSCs, LSECs and Heps show ~7000-8000 methylated promoters, with 60-70% similarity between all cell types. GO analysis for commonly methylated genes reveals involvement in germ cell development, segregating germ-line from somatic lineage methylation. HSCs, LSECs and HEPs also contain ~500-1000 uniquely methylated promoters; these are implicated in signaling and biosynthetic processes (HSCs), lipid transport and metabolism (LSECs), and chromatin assembly (HEPs). The promoter methylome of culture-activated HSCs deviates from that of their uncultured (quiescent) counterparts. HSC culture-induced activation also enhances methylation differences between individual donors; however this does not necessarily relate to changes in gene expression. HSc activation results in a net gain of promoter DNA methylation, despite the demethylation and de novo methylation of thousands of promoters. Our data provide to our knowledge the first genome-wide maps of promoter DNA methylation in human purified and uncultured liver cell types. Although methylation profiles are largely similar between HSCs, LSECs and hepatocytes, the detection of cell type-specific methylation patterns suggests a differential epigenetic programming of these cell types in the liver. Determine the promoter DNA methylation pattern of 3 uncultured, reshly isolated, human healthy liver cell types (hepatocytes (HEPs), liver sinusoidal endothelial cells (LSECs) and haptic stellate cells (HSCs), and of HSCs after a 24-h culture-induced activation.