Project description:Systemic immune responses induced by chronic hypercholesterolemia contribute to the initiation, progression and complications of atherosclerosis. However, the consequences of an alternate high fat diet and the associated variations in plasma cholesterol levels on atherosclerosis are unknown. To address this relevant issue concerning common situations where dietary habits change over time, we developed a novel protocol in athero-prone mice that allowed us to compare the effects of alternate versus continuous high fat diet (HFD) on atherosclerosis, the overall period of time of exposure to HFD being similar between groups. We showed that alternate HFD lead to accelerated atherosclerosis in Ldlr-/- and Apoe-/- mice compared to continuous HFD. The pro-atherogenic effect of alternate HFD was also found in Apoe-/-Rag2-/- mice lacking T, B, and NKT cells, ruling out a role for the adaptive immune system in the observed phenotype. Using different complementary in vivo approaches, we found that lipid-rich diet discontinuation in alternate group downregulated Runx1, a negative regulator downstream of TLR-4 pathways. As a result, after re-exposure to HFD, myeloid progenitors were more sensitive to hypercholesterolemia leading to acute differentiation into IL-1b- producing immature neutrophils, which caused a state of emergency myelopoiesis. Consecutively, neutrophils markedly increased in the peripheral blood, infiltrated atherosclerotic lesions and locally released neutrophil extracellular traps. Anti-Ly6G neutrophil depletion abolished the pro-atherogenic effects of alternate HFD. Specific deletion of Il1b and Il1b receptor confirmed that the IL-1b signaling pathway was a major driver of the pro-inflammatory and pro-atherogenic neutrophil signature. Finally, treatment with anti-IL-1b neutralizing antibody or inflammasome inhibitor during re-exposure to HFD reversed the pro-atherogenic effects of alternate HFD. In summary, we showed that alternate HFD accelerates atherosclerosis through IL-1b-dependent neutrophil progenitor reprogramming.
Project description:Systemic immune responses induced by chronic hypercholesterolemia contribute to the initiation, progression and complications of atherosclerosis. However, it is common for individuals to change dietary habits over time. The consequences of an alternating high fat diet and the associated variations in plasma cholesterol levels on atherosclerosis are unknown. To address this relevant issue, we developed a novel protocol in atherosclerosis-prone mice that allowed us to compare the effects of alternate versus continuous high fat diet (HFD) on atherosclerosis, while keeping the overall period of exposure to HFD similar between groups. We showed that an alternate HFD lead to accelerated atherosclerosis in Ldlr-/- and Apoe 55 -/- mice compared to continuous HFD. This pro-atherogenic effect of alternate HFD was also observed in Apoe-/-Rag2 57 -/- mice lacking T, B, and NKT cells, ruling out the role of the adaptive immune system in the observed phenotype. Employing various complementary in vivo approaches, we discovered that discontinuing HFD in the alternate group downregulated Runx1, a negative regulator of inflammatory signaling pathways in the myeloid lineage. Consequently, after re61 exposure to HFD, myeloid progenitors were primed to respond to HFD re-exposure by differentiating into IL-1-producing immature neutrophils, and inducing a state of emergency myelopoiesis. Subsequently, neutrophils markedly increased in the peripheral blood, infiltrated atherosclerotic lesions and locally released neutrophil extracellular traps. Anti-Ly6G neutrophil depletion abolished the pro-atherogenic effects of alternate HFD. Specific deletion of Il1b and Il1 receptor confirmed that the IL-1 signaling pathway was a major driver of the pro67 inflammatory and pro-atherogenic neutrophil signature. Finally, treatment with anti-IL-1 neutralizing antibody or an inflammasome inhibitor during re-exposure to HFD reversed the pro-atherogenic effects of alternate HFD. In summary, we showed that alternate HFD accelerates atherosclerosis through IL-1-dependent neutrophil progenitor reprogramming.
Project description:Atherosclerosis is the pathological basis of cardiovascular disease. Obstructive sleep apnea aggravates atherosclerosis, and chronic intermittent hypoxia (CIH) as a prominent feature of obstructive sleep apnea plays an important role during the process of atherosclerosis. The mechanisms of CIH in the development of atherosclerosis remain unclear. The microarray was used to investigate differentially expressed mRNAs and long noncoding RNAs (lncRNAs) in aorta from five groups of ApoE-/- mice fed with a high-fat diet and exposed to various conditions: normoxia for 8 weeks, CIH for 8 weeks, normoxia for 12 weeks, CIH for 12 weeks, or CIH for 8 weeks followed by normoxia for 4 weeks.
Project description:Examination of gene expression profiles from liver of C57BL/6 mice and LDL receptor deficient mice fed on either a low fat diet or a high fat Western-style diet for 12 weeks. Three replicates of each condition analyzed. Keywords = LDL receptor deficiency, high fat diet, atherosclerosis, liver
Project description:The macrophage subpopulations that have therapeutic benefits against atherosclerosis have not yet been fully understood. A single-cell RNA sequencing analysis were performed on the F4/80+ macrophages of apolipoprotein E-deficient (Apoe−/−) mice on a normal diet (ND), a high-fat diet (HFD), and a high-fat diet (HFD) with anti-CVI-mAb treatment. We analyze the diversity of M2 macrophages in atherosclerosis using single cell RNA sequencing (scRNA-seq).
Project description:In this study, single-cell sequencing of the BALF of CARDS patients yielded the following results: (1) IL1B+ neutrophils were significantly increased in the BALF of CARDS patients with exacerbated disease, which was associated with poor prognosis of CARDS patients, and this type of neutrophils underwent fatty acid metabolism reprogramming in comparison with other types of neutrophils, which may be related to their high-inflammatory response. (2) IL1B+ neutrophils promoted TNF secretion from hyperinflammatory type M1 macrophages through a caspase-dependent pathway, suggesting that neutrophil-macrophage interactions play an important role in the mechanism of CARDS development.
Project description:Examination of gene expression profiles from liver of C57BL/6 mice and LDL receptor deficient mice fed on either a low fat diet or a high fat Western-style diet for 12 weeks. Three replicates of each condition analyzed. Keywords = LDL receptor deficiency, high fat diet, atherosclerosis, liver Keywords: repeat sample
Project description:Experimental atherosclerosis was established by feeding Apoe KO mice a Western, high-fat diet for 12 weeks and experimental cerebral ischemia was established by middle cerebral artery occlusion. RNA-seq was perfomed to investigate the potential gene regulation of AS (LAA)-exo-dependent changes of microglia.