Project description:NASH is associated with signficant changes in liver macrophage composition. To gain insight into this heterogenity we performed scRNA on liver myeloid cells from mice fed a HFD for 16 weeks.
Project description:Macrophage-mediated inflammation is critical in the pathogenesis of non-alcoholic steatohepatitis (NASH). Here, we describe that, with high-fat, high-sucrose-diet feeding, mature TIM4pos Kupffer cells (KCs) decrease in number, while monocyte-derived Tim4neg macrophages accumulate. In concert, monocyte-derived infiltrating macrophages enter the liver and consist of a transitional subset that expresses Cx3cr1/Ccr2 and a second subset characterized by expression of Trem2, Cd63, Cd9, and Gpmnb; markers ascribed to lipid-associated macrophages (LAMs). The Cx3cr1/Ccr2-expressing macrophages, referred to as C-LAMs, localize to macrophage aggregates and hepatic crown-like structures (hCLSs) in the steatotic liver. In C-motif chemokine receptor 2 (Ccr2)-deficient mice, C-LAMs fail to appear in the liver, and this prevents hCLS formation, reduces LAM numbers, and increases liver fibrosis. Taken together, our data reveal dynamic changes in liver macrophage subsets during the pathogenesis of NASH and link these shifts to pathologic tissue remodeling.
Project description:The primary objective of this study was to compare global differences in transcriptional programming of resident and recruited alveolar macrophages in a time-limited murine model of lung inflammation. We first performed RNA sequencing of the resident and recruited alveolar macrophages from initiation through resolution of LPS-induced lung inflammation in the mouse. Our results indicate that despite existing in a shared environment, cell origin is the major determinant of programming of resident and recruited AMs during an acute inflammatory response. Major areas of difference include cell proliferation, inflammatory cytokine production and metabolism.
Project description:Tissue resident macrophages and recruited monocyte-derived macrophages contribute to host defense but also play pathological roles in a diverse range of human diseases. Multiple macrophage phenotypes are often represented in a diseased tissue, but we lack a deep understanding of the mechanisms that control diversification. Here we use a combination of genetic, genomic, and imaging approaches to investigate the origins and epigenetic trajectories of hepatic myeloid cells during a diet-induced model of nonalcoholic steatohepatitis (NASH). We provide evidence that distinct microenvironments within the NASH liver induce strikingly divergent transcriptomes of resident and infiltrating cells. Myeloid cell diversification results from both remodeling open chromatin landscapes of recruited monocytes and altering activities of preexisting enhancers of resident Kupffer cells. These findings provide evidence that niche-specific combinations of disease-associated environmental signals instruct resident and recruited macrophages to acquire distinct programs of gene expression and corresponding phenotypes.
Project description:Tissue resident macrophages and recruited monocyte-derived macrophages contribute to host defense but also play pathological roles in a diverse range of human diseases. Multiple macrophage phenotypes are often represented in a diseased tissue, but we lack a deep understanding of the mechanisms that control diversification. Here we use a combination of genetic, genomic, and imaging approaches to investigate the origins and epigenetic trajectories of hepatic myeloid cells during a diet-induced model of nonalcoholic steatohepatitis (NASH). We provide evidence that distinct micro-environments within the NASH liver induce strikingly divergent transcriptomes of resident and infiltrating cells. Myeloid cell diversification results from both remodeling open chromatin landscapes of recruited monocytes and altering activities of pre-existing enhancers of resident Kupffer cells. These findings provide evidence that niche-specific combinations of diseaseassociated environmental signals instruct resident and recruited macrophages to acquire distinct programs of gene expression and corresponding phenotypes.
Project description:Tissue resident macrophages and recruited monocyte-derived macrophages contribute to host defense but also play pathological roles in a diverse range of human diseases. Multiple macrophage phenotypes are often represented in a diseased tissue, but we lack a deep understanding of the mechanisms that control diversification. Here we use a combination of genetic, genomic, and imaging approaches to investigate the origins and epigenetic trajectories of hepatic myeloid cells during a diet-induced model of nonalcoholic steatohepatitis (NASH). We provide evidence that distinct microenvironments within the NASH liver induce strikingly divergent transcriptomes of resident and infiltrating cells. Myeloid cell diversification results from both remodeling open chromatin landscapes of recruited monocytes and altering activities of preexisting enhancers of resident Kupffer cells. These findings provide evidence that niche-specific combinations of disease-associated environmental signals instruct resident and recruited macrophages to acquire distinct programs of gene expression and corresponding phenotypes.
Project description:Tissue resident macrophages and recruited monocyte-derived macrophages contribute to host defense but also play pathological roles in a diverse range of human diseases. Multiple macrophage phenotypes are often represented in a diseased tissue, but we lack a deep understanding of the mechanisms that control diversification. Here we use a combination of genetic, genomic, and imaging approaches to investigate the origins and epigenetic trajectories of hepatic myeloid cells during a diet-induced model of nonalcoholic steatohepatitis (NASH). We provide evidence that distinct microenvironments within the NASH liver induce strikingly divergent transcriptomes of resident and infiltrating cells. Myeloid cell diversification results from both remodeling open chromatin landscapes of recruited monocytes and altering activities of preexisting enhancers of resident Kupffer cells. These findings provide evidence that niche-specific combinations of disease-associated environmental signals instruct resident and recruited macrophages to acquire distinct programs of gene expression and corresponding phenotypes.
Project description:Microglia and border-associated macrophages (BAMs) are brain-resident self-renewing cells with important homeostatic functions. However, their fate during and after severe episodes of brain inflammation and their relation to recruited monocyte-derived cells remain poorly understood. Here, we show that Trypanosoma brucei parasites invade the brain via its border regions, triggering a disruption of brain barriers and the recruitment of large numbers of monocytes. Fate-mapping combined with single-cell sequencing revealed the remarkable dynamics of resident macrophages, including microglia accumulation around the ventricular ependyma and an expansion of epiplexus cells. Resident macrophages were important for attracting peripheral immune cells and driving a pro-inflammatory response. However, recruited monocyte-derived macrophages reached higher cell densities and exhibited more transcriptional plasticity, adopting anti-microbial gene expression profiles not observed resident macrophages. Remarkably, recruited macrophages were short-lived and rapidly removed upon disease resolution, while activated resident macrophages progressively reverted towards a homeostatic state. Long-term transcriptional alterations were limited for microglia but more pronounced in BAMs. Together our results reveal the diverging responses and dynamics of resident and recruited macrophages upon Trypanosome invasion of the brain.
Project description:Non-alcoholic fatty liver disease (NAFLD) is characterized by a series of pathological changes that can progress from simple fatty liver disease to non-alcoholic steatohepatitis (NASH). The objective of this study is to describe changes in global gene expression associated with the progression of NAFLD. This study is focused on the expression levels of genes responsible for the absorption, distribution, metabolism and excretion (ADME) of drugs. Differential gene expression between three clinically defined pathological groups; normal, steatosis and NASH was analyzed. The samples were diagnosed as normal, steatotic, NASH with fatty liver (NASH fatty) and NASH without fatty liver (NASH NF). Genome-wide mRNA levels in samples of human liver tissue were assayed with Affymetrix GeneChipM-. Human 1.0ST arrays