Project description:We have applied single cell RNA sequencing (scRNA-seq) as an unbiased transcriptomics to characterize aortic immune cells in atherosclerosis. The scRNA-seq analysis revealed macrophage heterogeneity at the single-cell level in mouse atherosclerotic aorta.
Project description:We have applied single-cell RNA sequencing as an unbiased profiling strategy to interrogate and classify aortic macrophage heterogeneity at the single-cell level in atherosclerosis.
Project description:Atherosclerosis is modulated by immune cells. Understanding the diversity and heterogeneity in the aorta in steady state, as well as during different stages of disease will help to determine mechanisms promoting disease progression. To characterize the immune cells, we performed single cell RNA sequencing of aortic CD45+ leukocytes from C57BL/6 (WT) on chow diet and early disease Ldlr-/- mice fed high fat diet (HFD) for 21-days. The single cell RNA-seq analyses revealed the heterogeneity of aortic macrophages in steady state and early atherosclerotic disease.
Project description:In atherosclerosis, several immune cells are involved in plaque formation. Foam cell formation is a major cellular process in atherosclerotic lesion. It is important to understand which cells participate in foam cell formation. To characterize the immune cells and foam cells in atherosclerotic aorta, we performed single cell RNA sequencing of aortic CD45+ leukocytes from Ldlr-/- mice and foamy cells from ApoE-/- mice. The single cell RNA-seq analyses revealed the heterogeneity of aortic macrophages and foam cells in atherosclerotic aorta.
Project description:In atherosclerosis progression and regression, monocytes or monocyte-derived macrophages are the major immune cells in the plaque. It is important to understand the fate and characteristics of monocyte/macrophage during the plaque progression and regression. To characterize the fate of monocytes/macrophages, we performed single cell RNA sequencing of fate-mapped aortic CX3CR1-derived monocytes/macrophages from Cx3cr1CreERT2-IRES-YFP/+Rosa26floxed-tdTomato/+ mice with AAV-PCSK9 injection and fed a Western Diet. The single cell RNA-seq analyses revealed the heterogeneity of aortic macrophages and identified a stem-like cell cluster in atherosclerotic aorta.
Project description:<p>Macrophage-derived foam cell plays a pivotal role in the plaque formation and rupture during the progression of atherosclerosis. Foam cells are destined to divergent cell fate and functions in response to external stimuli based on their internal states, which however is hidden in the traditional studies based on population of cells. Herein, we used time-resolved and single-cell multi-omics to investigate the macrophage heterogeneity along foam cell formation. Dynamic metabolome and lipidome outlined the dual regulating axis of inflammation and ferroptosis. Single cell metabolomics and lipidomics further demonstrated a macrophage continuum featuring a differed susceptibility to apoptosis and ferroptosis. Using single-cell transcriptomic profiling, we verified the divergent cell fate toward apoptosis or ferroptosis. Therefore, the molecular choreography underlying the divergent cell fate during foam cell formation was revealed, which is of high significance for the understanding of the pathogenesis of atherosclerosis and development of new drug targets.</p>
Project description:We used single cell RNA-sequencing of aortic CD45+ cells, combined with immunohistologic, morphometric and flow cytometric analyses to define the changes in plaque immune cell composition, gene expression and function following miR-33 inhibition. We report that anti-miR-33 treatment of Ldlr–/– mice with advanced atherosclerosis reduced plaque burden and altered the plaque immune cell landscape by shifting the balance of pro- and anti-atherosclerotic macrophage and T cell subsets. By quantifying the kinetic processes that determine plaque macrophage burden, we found that anti-miR-33 reduced levels of circulating monocytes and splenic myeloid progenitors, decreased macrophage proliferation and retention, and promoted macrophage attrition by apoptosis and efferocytotic clearance. scRNA-sequencing of aortic arch plaques showed that anti-miR-33 reduced the frequency of MHCIIhi “inflammatory” and Trem2hi “metabolic” macrophages, but not tissue resident macrophages. Furthermore, anti-miR-33 led to derepression of distinct miR-33 target genes in the different macrophage subsets: in resident and Trem2hi macrophages, anti-miR-33 relieved repression of miR-33 target genes involved in lipid metabolism (e.g., Abca1, Ncoa1, Ncoa2, Crot), whereas in MHCIIhi macrophages, anti-miR-33 upregulated target genes involved in chromatin remodeling and transcriptional regulation. Anti-miR-33 also reduced the accumulation of aortic CD8+ and CD4+ Th1 cells, and increased levels of FoxP3+ regulatory T cells in plaques, consistent with an immune-dampening effect on plaque inflammation.
