Project description:HDL particles are known to possess several anti-atherogenic properties that include the removal of excess cholesterol from peripheral tissues, the maintenance of endothelial integrity, antioxidant and antiinflammatory activities. ApoA-I overexpression in apoE-deficient (EKO) mice has been shown to increase HDL levels and to strongly reduce atherosclerosis development. The aim of the study was to investigate gene expression patterns associated with atherosclerosis development in the aorta of EKO mice and how HDL plasma levels relate to gene expression patterns at different stages of atherosclerosis development and with different dietary treatments. Methods Eight weeks old EKO mice, EKO mice overexpressing human apoA-I (EKO/hA-I) and wild-type mice as controls were fed either Chow or Western diet for 6 or 22 weeks. Cholesterol distribution among lipoproteins was evaluated and atherosclerosis of the aorta was quantified. High-throughput sequencing technologies were used to analyse the transcriptome of the aorta of the three genotypes in each experimental condition. Results: In addition to the well-known activation of inflammation and immune response, the impairment of sphingolipid metabolism, phagosome-lysosome system and osteoclast differentiation emerged as relevant players in atherosclerosis development. The reduced atherosclerotic burden in the aorta of EKO mice expressing high levels of apoA-I was accompanied by a reduced activation of the immune system markers, as well as reduced perturbation of lysosomal activity and a better regulation of the sphingolipid synthesis pathway Conclusions. ApoA-I modulates atherosclerosis development in the aorta of EKO mice affecting the expression of pathways additional to those associated with inflammation and immune response
Project description:Background: Monocytes and macrophages are implicated in inflammation and atherosclerosis, whereas monocytes are involved in psoriasis lesion formation. We previously reported a psoriatic inflammation-associated significant decrease in the membrane protein caveolin-1 (CAV-1) in psoriasis patient monocytes. However, the phenotype of circulating monocytes and their macrophage differentiation in psoriasis patients remain unclear. Objective: We sought to clarify circulating monocyte and monocyte-derived macrophage (MDM) phenotypes in psoriasis patients with and without comorbidities. Method: Thirty-one patients with psoriasis vulgaris and 28 control subjects were included. Surface macrophage markers and inflammatory status were examined in circulating monocytes and MDMs from both groups. Expression of CD36, which mediates macrophage uptake of oxidized low-density lipoprotein (oxLDL), was evaluated in these cells. CAV-1-silenced monocytes were differentiated into macrophages to investigate the effects of CAV-1 downregulation on psoriatic inflammation and atherosclerosis. Results: Macrophage surface markers were detectable in circulating monocytes. A significant M1 shift was detected in monocytes and MDMs in psoriasis patients, including those without cardiovascular disease risk factors, as compared to controls. MDMs of psoriasis patients had more CD36-expressing cells, which are associated with atherosclerosis risk. Additionally, CAV-1-silencing in monocytes increased the likelihood of M1-biased macrophage differentiation and increased pro-inflammatory cytokine production. Conclusions: Monocytes from psoriasis patients were more likely to differentiate into M1-dominant macrophages, correlating with inflammatory status and CAV-1 expression. These aberrant inflammatory monocytes not only contribute to psoriatic inflammation by producing psoriatic cytokines, but also have a phenotype that could increase atherosclerosis risk by uptake of oxLDL and formation of foam cells.
Project description:Apolipoprotein A-I is well known to play a role in cholesterol efflux, but our studies suggest that apoA-I may also induce proinflammatory signaling. The molecular mechanisms behind apoA-I-mediated proinflammatory signaling have not yet been explored, nor has the link between this signaling and cholesterol efflux. We hypothesize that apoA-I is a novel TLR agonist, signaling through the MyD88 proinflammatory signaling adaptor to induce cytokines. Microarray analysis confirmed that a suite of pro-inflammatory genes are induced by apoA-I with varying dependence upon MyD88, and that MyD88 regulates >6% of the apoA-I-induced transcriptome.
Project description:High-throughput sequencing technologies were used to analyse the transcriptome of the spleen and axillary lymph node of apoE/apoA-I double deficient (DKO) mice, characterized by an almost complete HDL deficiency, and DKO mice overexpressing human apoA-I (DKO/hA-I), characterized by high HDL plasma levels. Mice were 30 weeks old and had been fed a normal laboratory diet.
Project description:To test the functional role of ApoA-I on microglia in the context of stress, we treated primary microglia with LPS stress with or without ApoA-I protein, and used bulk RNA-seq to evaluate if ApoA-I exhibits an anti-inflammatory role.
Project description:We found ApoA-I from blood can be taken up by microglia in the brain. To determine if ApoA-I from circulation is sufficient to restore microglial transcriptomic state to a more wild-type-like state, we performed a rescue experiment by intravenously injecting ApoA-I protein into adult Apoa1 KO mice and sorted microglia with or without ApoA-I uptake for bulk transcriptomic analysis.
Project description:Herein we demonstrate the efficacy of an unbiased proteomics screening approach for studying protein expression changes in the KC-Tie2 psoriasis mouse model, identifying multiple protein expression changes in the mouse and validating these changes in human psoriasis. KC-Tie2 mouse skin samples (n=3) were compared with littermate controls (n=3) using gel-based fractionation followed by label-free protein expression analysis. 5482 peptides mapping to 1281 proteins were identified and quantitated: 105 proteins exhibited fold-changes ≥2.0 including: stefin A1 (average fold change of 342.4 and an average P = 0.0082; cystatin A, human orthologue); slc25a5 (average fold change of 46.2 and an average P = 0.0318); serpinb3b (average fold change of 35.6 and an average P = 0.0345; serpinB1, human orthologue); and kallikrein related peptidase 6 (average fold change of 4.7 and an average P = 0.2474; KLK6). We independently confirmed mouse gene expression-based increases of selected genes including serpinb3b (17.4-fold, P < 0.0001), KLK6 (9.0-fold, P = 0.002), stefin A1 (7.3-fold; P < 0.001) and slc25A5 (1.5-fold; P = 0.05) using qRT-PCR on a second cohort of animals (n=8). Parallel LC/MS/MS analyses on these same samples verified protein-level increases of 1.3-fold (slc25a5; P < 0.05), 29,000-fold (stefinA1; P < 0.01), 322-fold (KLK6; P < 0.0001) between KC-Tie2 and control mice. To underscore the utility and translatability of our combined approach, we analyzed gene and protein expression levels in psoriasis patient skin and primary keratinocytes vs. healthy controls. Increases in gene expression for slc25a5 (1.8-fold), cystatin A (3.0-fold), KLK6 (5.8-fold) and serpinB1 (76-fold; all P < 0.05) were observed between healthy controls and involved lesional psoriasis skin and primary psoriasis keratinocytes. Moreover slc25a5, cystatin A, KLK6 and serpinB1 protein were all increased in lesional psoriasis skin compared to normal skin. These results highlight the usefulness of preclinical disease models using readily-available mouse skin and demonstrate the utility of proteomic approaches for identifying novel peptides/proteins that are differentially regulated in psoriasis that could serve as sources of auto-antigens or provide novel therapeutic targets for the development of new anti-psoriatic treatments.
Project description:Human mesenchymal stem cells are differentiated into osteoblasts in the presence or absence of ApoA-I treatment, the global gene profiles of MSCs with different time-points are compared. Day 0 is primary human MSCs without induction was used the baseline for comparision. We used microarrays to investigate the global gene expression profiles in hBM-MSCs with ApoA-I treatment for 1, 3, 5 days during osteogenesis
Project description:Aortic gene expression profiles show how APOA-I levels modulate infammation, lysosomal activity and sphingolipid metabolism in murine atherosclerosis