circDENND1B Participates in the Antiatherosclerotic Effect of IL-1β Monoclonal Antibody in Mouse by Promoting Cholesterol Efflux via miR-17-5p/Abca1 Axis

Inflammation is a crucial mediator of atherosclerosis, and several therapeutic methods that focus on inflammatory cytokines, including interleukin-1β (IL-1β), have proven effective in preventing atherogenesis. Circular RNAs (circRNAs) are a subclass of non-coding RNAs (ncRNAs) that can exert critical functions in the regulation of atherosclerosis. Here, using circRNA sequencing, we revealed that circRNA circDENND1B (mmu_circ_0000081) is a promising novel mediator of atherosclerosis in mouse. The expression of circDENND1B is negatively related to the progression of atherosclerosis and foam cell formation, and the upregulation of circDENND1B significantly alleviates foam cell formation induced by ox-LDL by promoting cholesterol efflux. Moreover, circDENND1B participates in the anti-atherosclerotic effect of IL-1β monoclonal antibody (IL-1β mAb), both in vivo and in vitro. With bioinformatic prediction and RNA pull-down assays, we determined that circDENND1B sponges mmu-miR-17-5p to promote Abca1 expression in cells treated with IL-1β mAb. Our study revealed that circDENND1B, a novel regulator of cholesterol efflux, is a potential therapeutic target in atherosclerosis and provides new insights into the interaction between inflammation and cholesterol transport.

The interaction of estrogen and CSE/H2S pathway in the development of atherosclerosis

Both estrogen and hydrogen sulfide (H2S) have been shown to inhibit the development of atherosclerosis. We previously reported that cystathionine γ-lyase knockout (CSE-KO) male mice develop atherosclerosis earlier than male wild-type (WT) mice. The present study investigated the interaction of CSE/H2S pathway and estrogen on the development of atherosclerosis in female mice. Plasma estrogen levels were significantly lower in female CSE-KO mice than in female WT mice. NaHS treatment had no effect on plasma estrogen levels in both WT and CSE-KO female mice. After CSE-KO and WT female mice were fed with atherogenic diet for 12 wk, plasma lipid levels were significantly increased and triglyceride levels decreased compared with those of control diet-fed mice. Atherogenic diet induced more atherosclerotic lesion, oxidative stress, intracellular adhesion molecule-1 (ICAM-1), and NF-κB in CSE-KO mice than in WT mice. Estrogen treatment of atherogenic diet-fed WT mice attenuated hypercholesterolemia, oxidative stress, ICAM-1 expression, and NF-κB in WT mice but not in atherogenic diet-fed CSE-KO mice. Furthermore, H2S production in both the liver and vascular tissues was enhanced by estrogen in WT mice but not in CSE-KO mice. It is concluded that the antiatherosclerotic effect of estrogen is mediated by CSE-generated H2S. This study provides new insights into the interaction of H2S and estrogen signaling pathways on the regulation of cardiovascular functions. NEW & NOTEWORTHY Female cystathionine γ-lyase (CSE)-knockout mice have significantly lower plasma estrogen levels and more severe early atherosclerotic lesion than female wild-type mice. H2S production in liver and vascular tissues is enhanced by estrogen via its stimulatory effect on CSE activity. The antiatherosclerotic effect of estrogen is mediated by CSE-generated H2S.

Experimental Study of Antiatherosclerosis Effects with Hederagenin in Rats

The research tries to establish Wistar rat’s model of atherosclerosis for evaluating the antiatherosclerotic effect of hederagenin and exploring its antiatherosclerosis-related mechanisms. The statistical data have shown that hederagenin exhibits multiple pharmacological activities in the treatment of hyperlipidemia, antiplatelet aggregation, liver protection, and anti-inflammation, indicating that hederagenin may exert a protective effect on vascular walls by improving lipid metabolism disorders and lipid deposition. The results show that hederagenin can correct the imbalance of endothelial function by inhibiting the release of large amounts of iNOS and increasing eNOS contents and inhibits the IKKβ/NF-κB signaling pathway to reduce the release of IL-6, IFN-γ, TNF-α, and other inflammatory factors. The experimental results indicated that hederagenin can inhibit or ameliorate the pathological changes associated with AS, displaying an excellent preventive function against AS.

Effect of Compound Chuanxiong Capsule on Inflammatory Reaction and PI3K/Akt/NF-κB Signaling Pathway in Atherosclerosis

Compound Chuanxiong Capsule (CCC), a Chinese herbal compound, can exhibit antiatherosclerotic effect; however, its mechanism is still unclear. This study is designed to study the mechanism of CCC on atherosclerosis in the ApoE-knockout (ApoE−/−) mice fed with a high-fat diet. After 6 weeks of high-fat feeding, 40 ApoE−/−mice were randomized (n=10) and treated with lipitor, high-dose or low-dose CCC, or distilled water (ApoE−/−group) for 7 weeks. The blood lipids in serum and the plaque areas of the mice were measured and the mRNA expressions of phosphatidylinositol-3-kinases (PI3K), Akt, nuclear factor-kappa B (NF-κB), tumor necrosis factor-α(TNF-α), and interleukin-6 (IL-6) of the aortae were determined. The data showed that CCC can significantly decrease the levels of blood lipids, atherosclerosis index, and plaque areas and increase collagen proportion in plaques as compared with the untreated mice (p<0.05,p<0.01). In addition, CCC can significantly reduce the mRNA expressions of PI3K, Akt, NF-κB, IL-6, and TNF-αin the mice fed with a high-fat diet (p<0.001). Thus, we concluded that CCC can inhibit inflammatory reaction in the ApoE−/−mice fed with a high-fat diet. This mechanism may be attributed to regulating PI3K/Akt/NF-κB signaling pathway.

Hypolipidemic Activity and Antiatherosclerotic Effect of Polysaccharide ofPolygonatum sibiricumin Rabbit Model and Related Cellular Mechanisms

Objective. To evaluate the hypolipidemic activity and antiatherosclerotic effect of polysaccharide ofPolygonatum sibiricum(PPGS), which is a kind of Chinese herbal medicine using the rhizome part of the whole herb.Materials and Methods. Thirty rabbits were divided into normal control group, model control group, and PPGS subgroups of 0.8, 1.6, and 3.2 mL/kg/day under random selection. In atherosclerosis model, the effects of PPGS on diverse blood lipids, foam cells number, and aortic morphology were evaluated. In the primary culture of endothelial cells (ECs), the activities of PPGS on both ECs proliferation and ECs injury were studied as well.Results. In atherosclerosis model, the hypolipidemic activities of PPGS were mainly focused on TC, LDL-C, and Lp(a). All changes on these factors were statistically significant compared with model group (P< 0.01), except TG and HDL-C. The intimal foam cell number of PPGS subgroups (0.8, 1.6, and 3.2 mL/kg/day) was significantly reduced than model control (P< 0.01). In the primary culture of endothelial cells (ECs), PPGS showed no effect on cell proliferation but preferred to protect EC from injury and apoptosis induced by H2O2and lipopolysaccharide (LPS).Discussion and Conclusion. The antiatherosclerotic effect of PPGS may be supported by its hypolipidemic activities, improving aortic morphology, and reducing foam cells number and ECs injury.

Cerivastatin represses atherogenic gene expression through the induction of KLF2 via isoprenoid metabolic pathways

Earlier clinical studies have reported that cerivastatin has an antiatherosclerotic effect that is unique among the statins. In our study, human THP-1 macrophage cells were used to study the effects of various statins on the expressions of the atherosclerotic genes and Kruppel-like factor 2 (KLF2). Cerivastatin significantly inhibited the two atherosclerotic genes, monocyte chemoattractant protein-1 (MCP-1) and C-C chemokine receptor type 2 (CCR2) at both the mRNA and protein levels, while the other statins did not. Accordingly, cerivastatin was also the most potent inducer of KLF2 transcription in the macrophages. An siRNA-induced reduction in KLF2 expression blocked the inhibition of MCP-1 and CCR2 by cerivastatin. When the cells were further treated with mevalonate, farnesylpyrophosphate (FPP) or geranylgeranyl pyrophosphate (GGPP), the effects of cerivastatin on KLF2, MCP-1 and CCR2 were obviously reversed. Thus, the results showed that cerivastatin was a potent inhibitor of the inflammation genes MCP-1 and CCR2 through the induction of KLF2. The regulation of MCP-1, CCR2 and KLF2 by cerivastatin was isoprenoid pathway dependent. Our studies suggest that the effect of cerivastatin on atherosclerotic genes and KLF2 expression may contribute to the cardioprotection observed in reported clinical studies.

Mosaicism of Mitochondrial Genetic Variation in Atherosclerotic Lesions of the Human Aorta

Objective.The aim of the present study was an analysis of heteroplasmy level in mitochondrial mutations 652delG, A1555G, C3256T, T3336C, 652insG, C5178A, G12315A, G13513A, G14459A, G14846A, and G15059A in normal and affected by atherosclerosis segments of morphologically mapped aortic walls.Methods.We investigated the 265 normal and atherosclerotic tissue sections of 5 human aortas. Intima of every aorta was divided according to morphological characteristics into segments with different types of atherosclerotic lesions: fibrous plaque, lipofibrous plaque, primary atherosclerotic lesion (fatty streak and fatty infiltration), and normal intima from human aorta. PCR-fragments were analyzed by a new original method developed in our laboratory on the basis of pyrosequence technology.Results.According to the obtained data, mutations G12315A and G14459A are significantly associated with total and primary atherosclerotic lesions of intimal segments and lipofibrous plaques (P≤0.01andP≤0.05, accordingly). Mutation C5178A is significantly associated with fibrous plaques and total atherosclerotic lesions(P≤0.01). A1555G mutation shows an antiatherosclerotic effect in primary lesion in lipofibrous plaques(P≤0.05). Meanwhile, G14846A mutation is antiatherogenic for lipofibrous plaques(P≤0.05).Conclusion.Therefore, mutations C5178A, G14459A, G12315A, A1555G, and G14846A were found to be associated with atherosclerotic lesions.

Metoprolol Reduces Proinflammatory Cytokines and Atherosclerosis in ApoE−/−Mice

A few studies in animals and humans suggest that metoprolol (β1-selective adrenoceptor antagonist) may have a direct antiatherosclerotic effect. However, the mechanism behind this protective effect has not been established. The aim of the present study was to evaluate the effect of metoprolol on development of atherosclerosis in ApoE−/−mice and investigate its effect on the release of proinflammatory cytokines. Male ApoE−/−mice were treated with metoprolol (2.5 mg/kg/h) or saline for 11 weeks via osmotic minipumps. Atherosclerosis was assessed in thoracic aorta and aortic root. Total cholesterol levels and Th1/Th2 cytokines were analyzed in serum and macrophage content in lesions by immunohistochemistry. Metoprolol significantly reduced atherosclerotic plaque area in thoracic aorta (P<0.05versus Control). Further, metoprolol reduced serum TNFαand the chemokine CXCL1 (P<0.01versus Control for both) as well as decreasing the macrophage content in the plaques (P<0.01versus Control). Total cholesterol levels were not affected. In this study we found that a moderate dose of metoprolol significantly reduced atherosclerotic plaque area in thoracic aorta of ApoE−/−mice. Metoprolol also decreased serum levels of proinflammatory cytokines TNFαand CXCL1 and macrophage content in the plaques, showing that metoprolol has an anti-inflammatory effect.

Guanxinkang Decoction Exerts Its Antiatherosclerotic Effect Partly through Inhibiting the Endoplasmic Reticulum Stress

Purpose. To investigate the antiatherosclerotic effect of Guanxinkang (GXK) decoction on the apoptosis, mitochondrial membrane potential (MMP), and endoplasmic reticulum stress (ERS) of human umbilical vein endothelial cells (HUVEC) pretreated with homocysteinemia (HCY).Materials and Methods. HUVEC were randomly divided into 5 groups: (1) blank control group (control), (2) model control group (model), (3) GXK low dose group, (4) GXK medium dose group, and (5) GXK high dose group. For the three GXK groups, HCY was given to reach the concentration of 3.0 mmol/L after HUVEC had been incubated with rabbit serum containing GXK for two hours. At 3, 6, 12, and 24 h after HCY had been incubated with the cells, the HUVEC were collected for test of the apoptosis rate, MMP, and GRP78 protein (reflecting ERS).Results. In the model control group, the apoptosis rate and GRP 78 protein expression of HUVEC significantly increased (P<0.05), while MMP significantly decreased (P<0.05) compared with the blank control group. After GXK treatment of medium and high doses, the apoptosis rate and the GRP 78 protein expression significantly (P<0.05) decreased, while MMP significantly increased (P<0.05) in a time-dependent manner compared with the model control group.Conclusion. GXK can antagonize the injury of HUVEC caused by HCY and the antagonism effect increases with the concentration and treatment duration of GXK, with the possible mechanism of GXK antagonism being through inhibiting ERS caused by HCY.

Antiatherosclerotic Effect of Korean Red Ginseng Extract Involves Regulator of G-Protein Signaling 5

Regulator of G-protein signaling 5 (RGS5), an inhibitor of Gα(q) and Gα(i) activation, has been reported to have antiatherosclerosis. Previous studies showed antiatherosclerotic effect of Korean red ginseng water extract (KRGE) via multiple signaling pathways. However, potential protective effect of KRGE through RGS5 expression has not been elucidated. Here, we investigated the antiatherosclerotic effect of KRGEin vivoandin vitroand its role on RGS5 mRNA expression. Elevated levels of total cholesterol, lactate dehydrogenase (LDH), and triglyceride (TG) in western diet groups of low-density lipoprotein receptor deficient LDLr−/−mice were reversed by oral administration of KRGE. KRGE suppressed transcriptional activity of tumor necrotic factor alpha (TNF-α), interleukin-6 (IL-6), and leptin in adipose tissue. It also potently repressed western diet-induced atheroma formation in aortic sinus. While KRGE showed reduced mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-1β, IL-6, and TNF-αin LPS-stimulated RAW264.7 cells, it enhanced mRNA expression of RGS5. Moreover, RGS5 siRNA transfection of microglia cells pretreated with KRGE reversed its inhibitory effect on the expression of iNOS, COX-2, and IL-1βmRNA. In conclusion, KRGE showed antiatherosclerotic and anti-inflammatory effects in western diet fed LDLr−/−mice and this effect could partly be mediated by RGS5 expression.