P4141Lack of IkBNS promotes cholate-containing high-fat diet-induced inflammation and atherogenesis in low-density lipoprotein (LDL) receptor-deficient mice

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
K Kitamura ◽  
K Isoda ◽  
K Akita ◽  
K Miyosawa ◽  
T Kadoguchi ◽  
...  

Abstract Background IκBNS is one of the nuclear IκB proteins and regulates a subset of Toll-like receptor (TLR) dependent genes. LPS acts as extremely strong stimulator of innate immunity. We tried to investigate whether stimulation of innate immunity could promote atherosclerosis in the IκBNS-deficient atherogenic mice. However all IκBNS-deficient mice died of LPS challenge at a dose of which almost all wild-type mice survived, because IκBNS-deficient mice are highly sensitive to LPS-induced endotoxin shock. Then, we decided to use a cholate-containing high fat diet (HFD(CA(+))), which has been widely used as an atherogenic diet in mice. Furthermore, HFD(CA(+)) has been shown to induce TLR4 mediated early inflammatory response. The present study aims to clarify the lack of IκBNS promotes atherogenesis in LDL receptor-deficient (LDLr−/−) mice fed HFD(CA(+)) compared with those fed a cholate-free HFD (HFD(CA(−)). Methods and results Mice that lacked IκBNS (IκBNS−/−) were crossed with LDLr−/− mice and formation of atherosclerotic lesions was analyzed after 6 weeks consumption of HFD(CA(+)) or HFD(CA(−)). The extent of atherosclerosis in the aorta (en face) was significantly increased in IκBNS−/−/LDLr−/−(CA(+)) mice compared with others after 6-week consumption of HFD (p<0.01) (Figure). Interestingly, HFD(CA(−)) did not induce significant atherosclerotic lesions in IκBNS−/−/LDLr−/− compared with LDLr−/− mice after 6-week consumption (Figure). Immunostaining of aortic root lesion revealed that HFD(CA(+)) significantly increased positive area of Mac-3 (macrophage) by 1.5-fold (p=0.01) and TLR4, interleukin-6 (IL-6) expression by 1.7-fold (P<0.05) and 1.5-fold (p<0.05) respectively in IκBNS−/−/LDLr−/− (CA(+)) compared to LDLr−/− (CA(+)) mice. Furthermore, active STAT3 (pSTAT3)-positive cells were significantly increased by 1.7-fold in the atherosclerotic lesions of IκBNS−/−/LDLr−/− (CA(+)) compared with LDLr−/− (CA(+)) mice (p<0.01). TLR4 positive areas, IL-6 positive areas, and pSTAT3 positive cells were overlapped with Mac-3, indicating that TLR4-IL-6-STAT3 axis was activated in macrophages in IκBNS−/−/LDLr−/− (CA(+)) mice. On the other hand, HFD(CA(−)) could not induce any difference in these immunoreactivities of arteriosclerotic lesions between IκBNS−/−/LDLr−/− (CA(−)) compared with LDLr−/− (CA(−)) mice. These findings suggest that IκBNS deficiency and HFD(CA(+)) promote atherogenesis in LDLr−/− mice via TLR4/IL-6/STAT3 pathway. Finally, we show the monocytes from peripheral blood of IκBNS−/−/LDLr−/− (CA(+)) mice were found to contain the most mounts of Ly6Chi among four groups, suggesting that lack of IκBNS enhances inflammation in the response HFD(CA(+)) feeding and thereby influence atherogenesis in IκBNS−/−/LDLr−/− mice. Aortic root atherosclerotic lesions Conclusions The present study is the first to demonstrate that the activation of innate immune system using HFD(CA(+)) induced significant inflammation and atherogenesis in IκBNS−/−/LDLr−/− compared with LDLr−/− mice.

2021 ◽  
Vol 10 (18) ◽  
Author(s):  
Feroz Ahmad ◽  
Robert D. Mitchell ◽  
Tom Houben ◽  
Angela Palo ◽  
Tulasi Yadati ◽  
...  

Background We have shown previously that low‐density lipoprotein (LDL) can be oxidized in the lysosomes of macrophages, that this oxidation can be inhibited by cysteamine, an antioxidant that accumulates in lysosomes, and that this drug decreases atherosclerosis in LDL receptor–deficient mice fed a high‐fat diet. We have now performed a regression study with cysteamine, which is of more relevance to the treatment of human disease. Methods and Results LDL receptor–deficient mice were fed a high‐fat diet to induce atherosclerotic lesions. They were then reared on chow diet and drinking water containing cysteamine or plain drinking water. Aortic atherosclerosis was assessed, and samples of liver and skeletal muscle were analyzed. There was no regression of atherosclerosis in the control mice, but cysteamine caused regression of between 32% and 56% compared with the control group, depending on the site of the lesions. Cysteamine substantially increased markers of lesion stability, decreased ceroid, and greatly decreased oxidized phospholipids in the lesions. The liver lipid levels and expression of cluster of differentiation 68, acetyl–coenzyme A acetyltransferase 2, cytochromes P450 (CYP)27, and proinflammatory cytokines and chemokines were decreased by cysteamine. Skeletal muscle function and oxidative fibers were increased by cysteamine. There were no changes in the plasma total cholesterol, LDL cholesterol, high‐density lipoprotein cholesterol, or triacylglycerol concentrations attributable to cysteamine. Conclusions Inhibiting the lysosomal oxidation of LDL in atherosclerotic lesions by antioxidants targeted at lysosomes causes the regression of atherosclerosis and improves liver and muscle characteristics in mice and might be a promising novel therapy for atherosclerosis in patients.


2019 ◽  
Vol 23 ◽  
pp. 100344
Author(s):  
Kenichi Kitamura ◽  
Kikuo Isoda ◽  
Koji Akita ◽  
Katsutoshi Miyosawa ◽  
Tomoyasu Kadoguchi ◽  
...  

PLoS ONE ◽  
2018 ◽  
Vol 13 (3) ◽  
pp. e0193737 ◽  
Author(s):  
Sarvenaz Metghalchi ◽  
Marie Vandestienne ◽  
Yacine Haddad ◽  
Bruno Esposito ◽  
Julien Dairou ◽  
...  

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Aijun Sun ◽  
Xueting Jin ◽  
Jingjing Zhao ◽  
Keqiang Wang ◽  
Fang Xu ◽  
...  

Aims: Probucol, an agent characterized by lipid-lowering and anti-oxidant property, retards atherosclerosis effectively. Our study aimed to test the hypothesis that probucol might act its anti-athersclerotic role by suppressing maturation of human monocyte-derived dendritic cells (h-monDC). Furthermore, we also used a LDLR-/- mice model fed a high-fat diet to detect whether probucol also perform its anti-atherosclerotic effect on suppressing DCs maturation in vivo. Methods: H-monDCs were derived by incubating purified human monocytes with GM-CSF and IL-4. H-monDCs were pre-incubated with or without probucol and stimulated by oxidized low-density lipoprotein (ox-LDL) in the presence or absence of heme oxygenase (HO-1) siRNA. In vivo studies, streptozotocin (STZ) induced LDLR-/- mice were fed either a high-fat (HF) diet or added with 0.5% probucol for 4 months. Expression of h-monDC membrane molecules and mice splenic CD11c+DC membrane molecules were analyzed by FACS, cytokines were measured by ELISA and the STAT1/CIITA associated signaling pathway was determined by Western blotting. Mice aortic lesions were observed by En face staining and the expression of CD11c+DCs within atherosclerotic plaques were shown under confocal microscopy. Results: Ox-LDL promoted h-monDC maturation and TNF-a production; and up-regulated STAT1 701 phosphorylation by activating HO-1 in STAT1/CIITA signaling pathway. These effects were inhibited by probucol. Knocking down HO-1 with specific siRNA blocked these effects of probucol. In LDLR-/- mice fed a high-fat diet, probucol treatment significantly regressed aortic atherosclerotic lesions, suppressed splenic CD11c+DCs maturation and IL-12p70 production; and resulted in absence of CD11c+DCs within atherosclerotic lesions. Conclusions: Our study indicated that probucol effectively suppressed maturation of h-monDC induced by ox-LDL through HO-1 activation, and retarded atherosclerosis at least partly through inhibiting maturations of CD11c+DCs in LDLR-/- mice.


2014 ◽  
Vol 232 (1) ◽  
pp. 40-51 ◽  
Author(s):  
S.T. Hasan ◽  
J.-M. Zingg ◽  
P. Kwan ◽  
T. Noble ◽  
D. Smith ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Débora Maria Soares de Souza ◽  
Guilherme de Paula Costa ◽  
Ana Luísa Junqueira Leite ◽  
Daniela Silva de Oliveira ◽  
Kelerson Mauro de Castro Pinto ◽  
...  

The protozoan Trypanosoma cruzi is responsible for triggering a damage immune response in the host cardiovascular system. This parasite has a high affinity for host lipoproteins and uses the low-density lipoprotein (LDL) receptor for its invasion. Assuming that the presence of LDL cholesterol in tissues could facilitate T. cruzi proliferation, dietary composition may affect the parasite-host relationship. Therefore, the aim of this study was to evaluate myocarditis in T. cruzi-infected C57BL/6 mice—acute phase—fed a high-fat diet and treated with simvastatin, a lipid-lowering medication. Animals (n=10) were infected with 5×103 cells of the VL-10 strain of T. cruzi and treated or untreated daily with 20 mg/kg simvastatin, starting 24 h after infection and fed with a normolipidic or high-fat diet. Also, uninfected mice, treated or not with simvastatin and fed with normolipidic or high-fat diet, were evaluated as control groups. Analyses to measure the production of chemokine (C-C motif) ligand 2 (CCL2), interferon- (IFN-) γ, interleukin- (IL-) 10, and tumor necrosis factor (TNF); total hepatic lipid dosage; cholesterol; and fractions, as well as histopathological analysis, were performed on day 30 using cardiac and fat tissues. Our results showed that the high-fat diet increased (i) parasite replication, (ii) fat accumulation in the liver, (iii) total cholesterol and LDL levels, and (iv) the host inflammatory state through the production of the cytokine TNF. However, simvastatin only reduced the production of CCL2 but not that of other inflammatory mediators or biochemical parameters. Together, our data suggest that the high-fat diet may have worsened the biochemical parameters of the uninfected and T. cruzi-infected animals, as well as favored the survival of circulating parasites.


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