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:Atherosclerosis is a growing concern in developed nations, necessitating the identification of therapeutic targets for advancing personalized medicine. Serum amyloid A3 (Saa3) has been linked to accelerated plaque progression by affecting cholesterol metabolism and modulation of inflammation. We hypothesize that knocking out Saa3 (Saa3-/-) could mitigate plaque development by regulating aortic immune cell subsetscompositions during atherosclerosis progression. Using a murine model, we induced atherosclerosis via a gain-of-function mutant PCSK9-encoding adeno-associated viral vector (AAVmPCSK9) in wild-type (WT) and Saa3-/- mice. Single-cell RNA sequencing revealed that Saa3-/- mice developed smaller plaques than WT mice, with and single-cell RNA sequencing revealed significant differences in aortic immune cell populations, particularly among aortic macrophages. Saa3-/-Trem2hi macrophages, characterized by high Gpnmb, Lpl, and Spp1 expressions, predominated over the typical resident foamy macrophages in WT mice.Saa3-/- compared to WT mice. SAA3 regulates cholesterol metabolism and inflammatory responses in foamy macrophages. Notably, aortic immune cells in atherosclerotic Saa3-/- mice also showed enhanced intercellular immune communication and increased signaling interactions, suggesting a shift towards an anti-inflammatory and tissue-repairing phenotype. Our study highlights the potential of Saa3 as a therapeutic target forkey modulator of aortic immune cells that impact atherosclerosis progression.
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:Atherosclerosis is a systemic and chronic inflammatory disease propagated by monocytes and macrophages. Yet, our knowledge on how transcriptional profiles of these cells evolve in time and space is limited. We aimed at characterizing gene expression changes in site-specific macrophages, i.e. atherosclerotic aorta versus remote peritoneal cavity, and in circulating monocytes during the course of atherosclerosis initiation and progression in Apoe deficient mice. Constructing a comparative directory of cell type- and disease stage-specific whole transcriptome information, we identified a distinctive gene regulation profile of aortic macrophages. Overall 1149 differentially expressed genes (DEG) were involved in the biological modulation of aortic macrophages, and they were further categorized into regulated early, late, and transitorily throughout the disease course. The commonality of gene regulation was surprisingly low among the three investigated cell types. Through complementary interrogation of murine and human single cell RNA sequencing datasets, we showcased the practicality of our directory, using the selected gene, Glycoprotein Nmb (Gpnmb), whose expression in aortic macrophages, and a subset of foamy macrophages in particular, strongly correlated with disease advancement during atherosclerosis initiation and progression. Our study provides a unique toolset to explore gene regulation of macrophage-related biological processes in and outside the atheromatous plaque at early and advanced disease stages for pathomechanistic insight and therapeutic target screening.
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: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.