Abstract 12315: Four-and-a-Half LIM Domain Protein-2 Absence Reduces Atherogenesis in Apolipoprotein E-deficient Mice: Role of Monocytic Immune Cells

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Talin Ebrahimian ◽  
David Simon ◽  
Stefania Simeone ◽  
Catherine A Lemarié ◽  
Maryam Heidari ◽  
...  

Background: Four-and-a-half LIM domain protein-2 (FHL2) is expressed in endothelial and vascular smooth muscle cells. It negatively regulates endothelial cell survival and migration, but its role in atherogenesis is unknown. Methods and Results: FHL2-deficient (FHL2-/-) mice were crossed with apolipoprotein E-deficient (ApoE-/-) mice to generate ApoE/FHL2-/- mice. After high-fat, high-cholesterol diet, ApoE/FHL2-/- mice displayed significantly smaller atherosclerotic plaques than ApoE-/- mice in the aortic sinus, the brachiocephalic artery and the aorta. This was associated with significantly enhanced collagen and smooth muscle cell contents and a significant 2-fold reduction of macrophage content within the plaques of ApoE/FHL-2-/- vs ApoE-/- mice. There was a significant reduction in aortic ICAM-1 mRNA and VCAM-1 protein expression in the plaques of ApoE/FHL2-/- mice. Aortic gene expression of CX3CL1 and CCL5 was significantly increased in ApoE/FHL2-/- vs ApoE-/- mice. Peritoneal thioglycollate injection elicited equivalent numbers of monocytes and macrophages in both groups, but a significantly lower number of pro-inflammatory Ly6C-high monocytes were recruited in ApoE/FHL2-/- vs ApoE-/- mice. Furthermore, mRNA levels of CX3CR1 were 2-fold higher in monocytes from ApoE/FHL2-/- vs ApoE-/- mice. Finally, we investigated the potential importance of myeloid cell FHL2 deficiency in atherosclerosis. After being irradiated, ApoE-/- or ApoE/FHL2-/- mice were transplanted with ApoE-/- or ApoE/FHL2-/- bone marrow. After high-fat, high-cholesterol diet, both chimeric groups developed significantly smaller plaques than ApoE-/- mice transplanted with ApoE-/- bone marrow. Conclusion: These results suggest that FHL2 in both myeloid and vascular cells may play an important role in atherogenesis by promoting pro-inflammatory chemokine production, adhesion molecule expression, and pro-inflammatory monocyte recruitment.

2013 ◽  
Vol 34 (9) ◽  
pp. 2217-2224 ◽  
Author(s):  
Wei Ling Florence Lim ◽  
Sin Man Lam ◽  
Guanghou Shui ◽  
Alinda Mondal ◽  
Daniel Ong ◽  
...  

Metabolites ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 326
Author(s):  
Joselyn N. Allen ◽  
Adwitia Dey ◽  
Jingwei Cai ◽  
Jingtao Zhang ◽  
Yuan Tian ◽  
...  

Non-alcoholic steatohepatitis (NASH) represents the progressive sub-disease of non-alcoholic fatty liver disease that causes chronic liver injury initiated and sustained by steatosis and necroinflammation. The Ron receptor is a tyrosine kinase of the Met proto-oncogene family that potentially has a beneficial role in adipose and liver-specific inflammatory responses, as well as glucose and lipid metabolism. Since its discovery two decades ago, the Ron receptor has been extensively investigated for its differential roles on inflammation and cancer. Previously, we showed that Ron expression on tissue-resident macrophages limits inflammatory macrophage activation and promotes a repair phenotype, which can retard the progression of NASH in a diet-induced mouse model. However, the metabolic consequences of Ron activation have not previously been investigated. Here, we explored the effects of Ron receptor activation on major metabolic pathways that underlie the development and progression of NASH. Mice lacking apolipoprotein E (ApoE KO) and double knockout (DKO) mice that lack ApoE and Ron were maintained on a high-fat high-cholesterol diet for 18 weeks. We observed that, in DKO mice, the loss of ligand-dependent Ron signaling aggravated key pathological features in steatohepatitis, including steatosis, inflammation, oxidation stress, and hepatocyte damage. Transcriptional programs positively regulating fatty acid (FA) synthesis and uptake were upregulated in the absence of Ron receptor signaling, whereas lipid disposal pathways were downregulated. Consistent with the deregulation of lipid metabolism pathways, the DKO animals exhibited increased accumulation of FAs in the liver and decreased level of bile acids. Altogether, ligand-dependent Ron receptor activation provides protection from the deregulation of major metabolic pathways that initiate and aggravate non-alcoholic steatohepatitis.


Chemosphere ◽  
2020 ◽  
pp. 128773
Author(s):  
Tarana Arman ◽  
Katherine D. Lynch ◽  
Michael Goedken ◽  
John D. Clarke

2009 ◽  
Vol 89 (6) ◽  
pp. 657-667 ◽  
Author(s):  
Jennifer H Yearley ◽  
Dongling Xia ◽  
Christine B Pearson ◽  
Angela Carville ◽  
Richard P Shannon ◽  
...  

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Vikash Kansal ◽  
Swastika Sur ◽  
Velidi H Rao ◽  
Devendra K Agrawal

Deficiency of Vitamin D is linked to an increased risk of hypertension, peripheral artery disease, and myocardial infarction and is a major risk factor for the development of human atherosclerosis. Atheromatous cytokines, including TNF-α, IL-6 and IFN-γ, and EGF receptor family growth factors are released at the site of atherosclerosis and act on proteolytic enzymes, MMPs (matrix metalloproteinases), ADAMs (a disintegrin and metalloproteinases), and ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs). ADAM-12 activates EGFR resulting in increased migration and proliferation of smooth muscle cells (SMCs). The aim of this study was to examine the effect of vitamin D on IL-6-induced ADAM-12 expression and SMC migration and proliferation. Micro-swine were fed with either vitamin D-deficient high cholesterol diet or high cholesterol diet containing 900 IU of vitamin D for 6 months. After six months when serum cholesterol levels ranged from 500-600 mg/dL, vitamin D-deficient group continued on the same deficient diet, whereas the other group received supplementation of vitamin D (1,000 IU/d) for 6 months. The mRNA expression of ADAM-12 and EGFR in whole carotid artery and in IL-6-treated SMCs was quantified by qPCR. The proliferation was assayed by CyQuant NF cell proliferation assay. The mRNA transcripts of ADAM-12 and EGFR were significantly increased in carotid arteries from Vitamin D-deficient than in vitamin D- supplemented swine. Treatment of SMCs with IL-6 also increased the mRNA transcripts of ADAM-12 and EGFR in vitamin D-deficient swine SMCs compared to vitamin D-supplemented swine SMCs. The cell proliferation was higher in SMCs isolated from Vitamin D-deficient swine carotid artery compared to vitamin D- supplemented swine carotid artery. Together, these results suggest that Vitamin D regulates ADAM-12-mediated activation of EGFR and vitamin D deficiency further enhances proliferation of SMCs, which is potentiated by atheromatous cytokines.


2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Alex Sotolongo ◽  
Yi-Zhou Jiang ◽  
John Karanian ◽  
William Pritchard ◽  
Peter Davies

Objective: One of the first clinically detectable changes in the vasculature during atherogenesis is the accumulation of cholesterol within the vessel wall. Hypercholesterolemia is characterized by dysfunctional endothelial-dependent vessel relaxation and impaired NOS3 function. Since DNA methylation at gene promoter regions strongly suppresses gene expression, we postulated that high-fat/high-cholesterol diet suppresses endothelial NOS3 through promoter DNA methylation. Methods: Domestic male pigs were fed control diet (CD) or isocaloric high fat and high cholesterol diet (HC; 12% fat and 1.5% cholesterol) for 2, 4, 8 or 12 weeks prior to tissue collection. Furthermore, to determine the effects of risk factor withdrawal, an additional group of swine received HC for 12 weeks and then CD for 8 weeks; a control group received HC continuously for 20 weeks. Endothelial cells were harvested from common carotid aorta. In parallel in vitro studies, cultured human aortic endothelial cells (HAEC) were treated with human LDL, GW3956 (LXR agonist) and RG108 (DNA methyltransferase [DNMT] inhibitor). In cells from both sources, DNA methylation at the NOS3 promoter was measured using methylation specific pyro sequencing, and endothelial gene expression was measured using RT PCR. Results: HC diet increased plasma cholesterol level from 75 mg/dl on CD to a plateau of about 540 mg/dl within 2 weeks. Endothelial NOS3 expression was significantly reduced (71±9 % of CD) after 4 weeks of HC, a level sustained at subsequent time points. Withdrawal of HC for 8 weeks did not recover NOS3 expression. After 12-week HC, the NOS3 promoter was hypermethylated. Withdrawal of HC did not reverse NOS3 promoter methylation. In vitro treatment of HAEC with human LDL (200 mg/dl total cholesterol) or GW3956 (5μM) suppressed NOS3 mRNA to 50% and 30% respectively, suggesting that LXR/RXR is involved in suppression of NOS3. Nitric oxide production was consistently suppressed by GW3959. Both could be reversed through inhibition of DNMTs by RG108. Conclusions: DNA methylation and LXR/RXR pathway can mediate the HC-suppression of endothelial NOS3. The study identifies novel pharmaceutical targets in treating endothelial dysfunction. Crosstalk between these pathways is under investigation.


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