Project description:Hyperlipidemia is a well-established risk factor for cardiovascular diseases. Trillions of people worldwide display mildly elevated levels of plasma lipids and cholesterol due to diet and life-style. The relationship between severe hyperlipidemia and thrombosis has been extensively investigated, but the effects of the preliminary stages of hyperlipidemia on platelet function are unclear. Therefore, we investigated how moderate elevation of different plasma lipid profiles influence platelet activation and thrombus formation, as compared to higher plasma lipid concentrations. Hyperlipidemic Apoe-/- and Ldlr-/- and wild-type mice were fed a normal chow diet, resulting in mildly increased plasma cholesterol. Blood from both knockout mice was used in comparison to wild-type mice, for multiparameter ex vivo measurements of thrombus formation under flow. Whole blood (fibrin-)thrombus formation on collagen in the absence or presence of coagulation (with(out) tissue factor), indicated enhancement of the thrombotic process in both knockout mice. These effects were not further aggravated in aged mice, as well as in Apoe-/- mice on high fat diet with very high plasma cholesterol levels. Bone marrow chimeras of wild-type or Ldlr-/- platelets into irradiated Ldlr-/- recipient mice showed similar thrombus formation patterns. This suggested that hyperlipidemia itself, not the platelet LDL receptor deficiency is responsible for the altered platelet activation status in Ldlr-/- mice. Exploration of the platelet proteome revealed high similarity between the three genotypes, although some proteins showed significantly changed expression in Apoe-/- mice. Finally, platelet lipidomic analysis showed an increased lipid profile in mildly hyperlipidemic mice, which may further contribute to the observed prothrombotic phenotype
Project description:To explore the effect of hyperlipidemia on macrophages' innate immune response to Porphyromonas gingivalis invasion 12 samples, 3 replicates in 4 groups, with cells from hyperlipidemic ApoE deficient mice and nonhyperlipidemic C57BL/6 mice stimulate with or without P.gingivalis(Pg)
Project description:Hyperlipidemia and hypertension might play a role in cardiac fibrosis, in which a heterogeneous population of fibroblasts seems important. However, it is unknown whether CD34+ cells are involved in the pathogenesis of cardiac fibrosis. This study aimed to investigate the mechanism of CD34+ cell differentiation in cardiac fibrosis during hyperlipidemia. By analyzing the transcriptomes of single cells from the Cd34-CreERT2;R26-tdTomato&ApoE-/- heart, we also demonstrated the dynamics of cell landscape during cardiac fibrosis in the hypertrophic heart with hyperlipidemia.
Project description:We performed single cell RNA sequencing (scRNA-seq) for 6,574 cells from the aortic valves of C57BL/6J (wild type), Ldlr-/-, and Apoe-/- mice. The extensive single cell profiles depicted hyperlipidemia-associated cellular dynamics in aortic valves.
Project description:Caspase-1 activation senses metabolic danger-associated molecular patterns and mediates the initiation of inflammation. Here, we reported that caspase-1 contributes to hyperlipidemia-induced modulation of vascular cell gene expression during early atherosclerosis in vivo. Our results demonstrate the therapeutic potential of caspase-1 inhibition in the treatment of cardiovascular diseases. All mice were in a C57B/L6 strain background. Male wild-type mice, Apolipoprotein E (ApoE) gene knockout mice, and ApoE/Caspase-1 double gene deficient mice were fed with high fat diet for 3 weeks starting from 8 weeks to induce early dyslipidemia. At 11-week of age, aortas from these mice were used for microarray analysis. 5 biological replicates in each group.
Project description:To comprehensively elucidate the possible mechanism of short-term administration of emodin on the metabolic disturbance in vivo, our study utilized both LC/MS and NMR platforms for untargeted metabolomics studies. These analyses aimed to identify potential biomarkers associated with emodin-induced metabolic disturbances in mice. Subsequently, we delved into lipidomics to explore lipid metabolism systematically and determined the position of C=C double bonds in unsaturated lipids.
Project description:The multi-ligand Receptor for AGE (RAGE) contributes to atherosclerosis in apolipoprotein (ApoE) null mice in both the non-diabetic and diabetic states. Previous studies using soluble RAGE, the extracellular ligand-binding domain of RAGE, or homozygous RAGE null mice showed that blockade or deletion of RAGE resulted in marked reduction in atherosclerotic lesion area and complexity compared to control animals. In parallel, significant down-regulation of inflammatory mediators and matrix metalloproteinases was evident in ApoE null mice aortas devoid of RAGE compared to those of ApoE null RAGE-expressing mice. Although these findings suggested that RAGE triggered pro-atherogenic mechanisms via regulation of inflammatory gene expression, these studies did not reveal the broader pathways by which RAGE contributed to atherosclerosis in ApoE null mice. Therefore, we performed Affymetrix gene expression arrays on aortas of non-diabetic and diabetic ApoE null mice expressing RAGE or devoid of RAGE at nine weeks of age, as this reflected a time point at which frank atherosclerotic lesions were not yet present, but, that we would be able to identify the genes likely involved in diabetes- and RAGE-dependent atherogenesis. The comparisons were as follows: 1. diabetic ApoE null relative to non-diabetic ApoE null; 2. non-diabetic ApoE null / RAGE null relative to non-diabetic ApoE null; 3. diabetic ApoE null / RAGE null relative to non-diabetic ApoE null / RAGE null; and 4. diabetic ApoE null / RAGE null relative to diabetic ApoE null aorta. Our data reveal that there is very little overlap of the genes which are differentially expressed both in the onset of diabetes in ApoE null mice, and in the effect of RAGE deletion in diabetic ApoE null mice. We next performed a Pathway-Express analysis to determine the pathways that were most associated with the onset of diabetes in ApoE null mice and the effect of RAGE gene deletion in diabetic ApoE null mice. Rigorous statistical analysis was undertaken and revealed that the transforming growth factor-beta pathway (tgf-beta) and focal adhesion pathways might be expected to play a significant role in both the mechanism by which diabetes facilitates the formation of atherosclerotic plaques in ApoE null mice, and the mechanism by which deletion of RAGE ameliorates this effect. We focused on three genes of the tgf-betafamily which were found to be up-regulated in diabetic vs. non-diabetic ApoE null aorta, and which were reduced by deletion of RAGE. These included: thrombospondin1 (Thbs1), transforming growth factor-beta (tgf-beta) and rho-associated kinase (ROCK1). Real-time quantitative polymerase chain reaction and Western blotting experiments were performed, as well as ROCK1 activity assays in mouse aorta, and validated the findings of the Affymetrix gene array. Further, confocal microscopy revealed that a principal cell type in the ApoE null aorta expressing these factors was the vascular smooth muscle cell. Our data suggest the novel finding that the observed reduction of accelerated atherosclerosis in diabetic ApoE null / RAGE null vs. diabetic ApoE null mice occurs, all or in part, through the ROCK1 branch of the TGF-betapathway. We have inferred a detailed mechanism for this process. Taken together, these data suggest that suppression of ROCK1 activity in the atherosclerosis-vulnerable vessel wall, especially in diabetes, but in non-diabetes as well, may underlie the beneficial effects of RAGE antagonism and genetic deletion in murine models. These findings highlight logical and novel targets for therapeutic intervention in cardiovascular disease and diabetes. 1. diabetic ApoE null relative to non-diabetic ApoE null; 2. non-diabetic ApoE null / RAGE null relative to non-diabetic ApoE null; 3. diabetic ApoE null / RAGE null relative to non-diabetic ApoE null / RAGE null; and 4. diabetic ApoE null / RAGE null relative to diabetic ApoE null aorta. There were 4 mice in each group initially. However there are only 3 non-diabetic ApoE null / RAGE null mice in the final experimental sample in group 3 due to a failure to generate cRNA from that sample. All samples were normalized to remove chip-dependent regularities using the RMA method. Chips and controls at each combination of genotype and disease sate were normalized together. The statistical significance of differential expression was calculated using the empirical Bayesian LIMMA (LInear Model for MicroArrays) method A cut-off B>0 was used for the statistical significance of gene expression.
Project description:Atherosclerosis is an autoimmune disease characterized by lipid imbalances and chronic inflammation within blood vessels with limited preventive and treatment options currently available. Previous experiments have demonstrated the atheroprotective potential of collagen 6 subtype alpha6 (COL6A6) in apolipoprotein E-deficient (ApoE-/-) mice with hyperlipidemia. However, the mechanism underlying the anti-atherosclerotic effects of COL6A6 remains elusive. This knowledge gap was addressed in the present study by immunizing ApoE-/- mice with the Pep_A6 vaccine, comprising a COL6A6 peptide-KLH (keyhole limpet hemocyanin) conjugate and aluminum (Alum) hydroxide adjuvant, and conducting a series of experiments. Our objective was to investigate the efficacy of the Pep_A6 vaccine, focusing on immune responses and lipid metabolism. Our finding showed that the Pep_A6 vaccine represents a novel approach to combat atherosclerosis by inducing a large increase in Treg cells, the generation of antigen-specific antibodies and regulating lipid metabolism.
Project description:Inbred mouse strains C57BL/6J (B6) and C3H/HeJ (C3H) exhibit a marked difference in their susceptibility to atherosclerosis and the arterial wall has proven to be a source of the difference in atherosclerosis susceptibility. Genome-wide gene expression analysis was conducted in aortic walls of the two strains. Total RNA was extracted from aortas of 6-week-old female B6 and C3H apoE-deficient (apoE-/-) mice fed a chow or Western diet. 1514 genes in chow fed mice and 590 genes in Western fed mice were found to be differentially expressed between the two strains. RNA was extracted from aorta using a Trizol protocol. Total RNA was pooled in an equal amount from 4 mice for each group. Standard Affymetrix procedures were performed using 8ug of total RNA. Microarrays were used to detect gene expression in aortic walls of two apoE-deficient mouse strains when fed a chow or western diet. Keywords: atherosclerosis, arterial walls, C57BL/6, C3H/HeJ, Inbred strains, Hyperlipidemia, and Western diet
Project description:The multi-ligand Receptor for AGE (RAGE) contributes to atherosclerosis in apolipoprotein (ApoE) null mice in both the non-diabetic and diabetic states. Previous studies using soluble RAGE, the extracellular ligand-binding domain of RAGE, or homozygous RAGE null mice showed that blockade or deletion of RAGE resulted in marked reduction in atherosclerotic lesion area and complexity compared to control animals. In parallel, significant down-regulation of inflammatory mediators and matrix metalloproteinases was evident in ApoE null mice aortas devoid of RAGE compared to those of ApoE null RAGE-expressing mice. Although these findings suggested that RAGE triggered pro-atherogenic mechanisms via regulation of inflammatory gene expression, these studies did not reveal the broader pathways by which RAGE contributed to atherosclerosis in ApoE null mice. Therefore, we performed Affymetrix gene expression arrays on aortas of non-diabetic and diabetic ApoE null mice expressing RAGE or devoid of RAGE at nine weeks of age, as this reflected a time point at which frank atherosclerotic lesions were not yet present, but, that we would be able to identify the genes likely involved in diabetes- and RAGE-dependent atherogenesis. The comparisons were as follows: 1. diabetic ApoE null relative to non-diabetic ApoE null; 2. non-diabetic ApoE null / RAGE null relative to non-diabetic ApoE null; 3. diabetic ApoE null / RAGE null relative to non-diabetic ApoE null / RAGE null; and 4. diabetic ApoE null / RAGE null relative to diabetic ApoE null aorta. Our data reveal that there is very little overlap of the genes which are differentially expressed both in the onset of diabetes in ApoE null mice, and in the effect of RAGE deletion in diabetic ApoE null mice. We next performed a Pathway-Express analysis to determine the pathways that were most associated with the onset of diabetes in ApoE null mice and the effect of RAGE gene deletion in diabetic ApoE null mice. Rigorous statistical analysis was undertaken and revealed that the transforming growth factor-β pathway (tgf-β) and focal adhesion pathways might be expected to play a significant role in both the mechanism by which diabetes facilitates the formation of atherosclerotic plaques in ApoE null mice, and the mechanism by which deletion of RAGE ameliorates this effect. We focused on three genes of the tgf-β family which were found to be up-regulated in diabetic vs. non-diabetic ApoE null aorta, and which were reduced by deletion of RAGE. These included: thrombospondin1 (Thbs1), transforming growth factor-β2 (tgf-β2) and rho-associated kinase (ROCK1). Real-time quantitative polymerase chain reaction and Western blotting experiments were performed, as well as ROCK1 activity assays in mouse aorta, and validated the findings of the Affymetrix gene array. Further, confocal microscopy revealed that a principal cell type in the ApoE null aorta expressing these factors was the vascular smooth muscle cell. Our data suggest the novel finding that the observed reduction of accelerated atherosclerosis in diabetic ApoE null / RAGE null vs. diabetic ApoE null mice occurs, all or in part, through the ROCK1 branch of the TGF-β pathway. We have inferred a detailed mechanism for this process. Taken together, these data suggest that suppression of ROCK1 activity in the atherosclerosis-vulnerable vessel wall, especially in diabetes, but in non-diabetes as well, may underlie the beneficial effects of RAGE antagonism and genetic deletion in murine models. These findings highlight logical and novel targets for therapeutic intervention in cardiovascular disease and diabetes.