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Background: Atherosclerosis is a progressive chronic disease characterised by aberrant lipid metabolism and a maladaptive inflammatory response. As atherosclerosis-driven cardiovascular disease remains the major cause of morbidity and mortality worldwide, more effective clinical therapies are urgently needed. Traditional Chinese Medicine (TCM) has demonstrated efficacy against atherosclerosis, with Qing-Xue-Xiao-Zhi formula (QXXZF) having been approved for clinical treatment of patients with atherosclerosis. However, the mechanisms underlying the anti-atherosclerotic activity of QXXZF remain unknown., Purpose: To investigate the anti-atherosclerotic effect of QXXZF and reveal its mechanisms using preclinical models., Methods: In vivo, apolipoprotein E-deficient (ApoE -/- ) mice were fed a high-fat and high-choline diet (HHD) to induce atherosclerosis. Serum metabolomic profiling was used to identify the concentration of trimethylamine N-oxide (TMAO) in mice. In vitro, RAW264.7 macrophages and bone marrow-derived macrophages (BMDMs) from WT and TLR4 -/- C57BL/6 mice were used to explore the effects of QXXZF on macrophages. After confirming the therapeutic effects of QXXZF, mass spectrometry and network pharmacology analyses were used to predict and investigate the main components and the anti-atherogenic mechanisms of QXXZF in the context of atherosclerosis., Results: Our results showed QXXZF significantly suppressed the development of atherosclerosis, as evidenced by the decreased atherosclerotic plaques in the aorta and aortic root, reduced plasma lipid levels and decreased serum TMAO content in HHD-fed ApoE -/- mice. Meanwhile, QXXZF effectively reduced foam cell formation in oxidized low-density lipoprotein (ox-LDL) and TMAO-stimulated RAW264.7 macrophages and BMDMs. Moreover, QXXZF facilitated reverse cholesterol transport (RCT) in macrophages by upregulating the expression of cholesterol efflux-related genes PPARγ/LXRα/ABCA1/ABCG1. Mechanistic studies revealed that QXXZF influenced cholesterol metabolism by inhibiting the TLR4-mediated nuclear factor kappa B (NF-κB) axis. Importantly, TLR4 knockout abolished the influence of QXXZF on macrophages., Conclusion: QXXZF promotes lipid efflux and inhibits macrophage-mediated inflammation, producing a therapeutic effect against atherosclerosis. Our study provides new insight into the mechanism of QXXZF against atherosclerosis., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Background and Aims: High-fat diet (HFD) is reported to induce atherosclerosis and insulin resistance. Macrophage lipid accumulation has been implicated as key mediators during the development of HFD-induced atherosclerosis. Traditional Chinese formula, which has long been used to improve disorder of glucose and lipid metabolism of patients, is now gradually being used as complementary therapy. This study aimed to investigate the effect of Danhong injection (DHI), a Chinese medicine used for the treatment of coronary artery disease, on atherosclerosis and its underlying mechanisms., Methods and Results: We observed the effects of DHI on HFD-induced atherosclerosis in a mice model, macrophage lipid accumulation in an ox-LDL-stimulated macrophage model, and the role of PI3K/AKT insulin pathway in the process of DHI ameliorating atherosclerosis. The data demonstrated that DHI attenuated atherosclerosis by ameliorating blood lipids, reducing the atherosclerotic index and atherosclerotic plaque area in HFD-induced atherosclerotic mice, and inhibiting TC levels in an ox-LDL-induced macrophage model. By estimating the levels of serum insulin resistance-related indexes and protein expression of GLUT-4, DHI treatment dramatically inhibited the levels of fasting serum NEFA and fasting serum insulin and promoted the protein expression of GLUT-4 in aortas of the HFD-induced atherosclerotic mice. Moreover, according to the hints provided by microarray-based transcriptional profiling, the results demonstrated that DHI treatment also promoted the activation of PI3K/AKT insulin signaling pathway induced by IRS-1 in aortas of HFD-induced atherosclerotic mice. Furthermore, in an ox-LDL-induced macrophage model, the activation of PI3k/AKT signaling pathway also effectively functioned in the process of DHI inhibiting macrophage lipid accumulation., Conclusions: These results highlight that DHI treatment attenuates atherosclerosis and macrophage lipid accumulation by promoting the activation of PI3K/AKT insulin signaling pathway. It provides new insights into the molecular mechanism of DHI and its therapeutic potential in the treatment of atherosclerosis.

Type 2 diabetes is considered a "risk equivalent" for cardiovascular disease, rosiglitazone, as an insulin sensitizer, has been explored as a novel therapeutic drug for the prevention of cardiovascular disease, but whether it can stabilize vulnerable atherosclerotic plaques is still unknown. Our study aims to investigate the effect of rosiglitazone on plaque stability in fat-fed ApoE-knockout mice. Our findings showed that rosiglitazone can stabilize the vulnerable atherosclerotic plaques in fat-fed ApoE-knockout mice by modifying the plaque composition as well as decreasing the number of buried fibrous caps and its anti-inflammatory effect probably is the key mechanism through which promotes the plaque more stable.

Increasing evidence indicated that plaque stabilization is attributed to the composition of the atherosclerotic plaque, and inflammation plays an important role in the formation and progress of vulnerable atherosclerotic plaque (VAP), which is prone to rupture. Emodin, an important component of traditional Chinese herb rhubarb, has obvious anti-inflammatory effect, although its effect on atherosclerotic plaque stabilization is unknown. Apolipoprotein E (ApoE) is an important component of plasma lipoprotein with anti-atherosclerosis function, and the plaque in the aorta of ApoE-deficient mice has been demonstrated with characteristics of VAP. Therefore, this study was designed to determine whether emodin can stabilize the VAP in the ApoE-deficient mice and explain the possible mechanism. After fat-fed for 13 weeks, mice were randomized into three groups (11 animals/group) and intragastrically administrated with emodin, simvastatin or distilled water for 13 weeks, respectively. The plaque stability was evaluated by the morphology and composition of atherosclerotic plaques. Additionally, the expression of peroxisomal proliferator-activated receptor-gamma (PPAR-gamma), granulocyte-macrophage colony-stimulating factor (GM-CSF), and matrix metalloproteinase 9 (MMP-9) in plaques was determined by the immunohistochemistry method. We showed that emodin could decrease the lipid core area and the ratio of lipid to collagen content in plaques. In addition, emodin significantly inhibited the expression of GM-CSF and MMP-9, whereas it induced the expression of PPAR-gamma in plaques. In conclusion, these results suggest that emodin can stabilize the VAP in the aortic root of ApoE-knockout mice, which is probably due to its anti-inflammatory effect.

Aim To investigate the effects of astragalus polysaccharide and hirudin combined intervention on lipid accumulation, mitochondrial membrane potential and apoptosis-related proteins in macrophages induced by oxidized low density lipoprotein (ox-LDL). Methods RAW264. 7 cells were incubated with 100 mg/ L ox-LDL for 24 h to establish a foam-cell model, which were treated by astragalus polysaccharide and hirudin after dose optimization. The control group, model group, astragalus polysaccharide group, hirudin group and the combined intervention of the two drugs group were established. Oil red O staining and oxidase method were used to detect the cholesterol contents in macrophages induced by ox-LDL, flow cytometry was used to detect the early apoptosis rate, late apoptosis rate and total apoptosis rate of macrophages, the changes of mitochondrial membrane potential were detected by laser confocal microscopy, Western blot was used to detect the expression levels of anti-apoptotic protein Bcl-2, proapoptotic protein Caspase-3 and Bax. Results The contents of cholesterol in macrophages of the astragalus polysaccharide and hirudin combined intervention group were decreased than those in the hirudin group or astragalus polysaccharide group significantly (P<0.05). Compared with the model group, the astragalus polysaccharide and hirudin combined intervention could reduce the early apoptosis rate and total apoptosis rate of macrophages induced by ox-LDL (P<0.01), increase the mitochondrial membrane potential of macrophages (P<0.01), reduce the expressions of Caspase-3 and Bax, and increase the expression of Bcl-2 protein (P< 0.05) significantly. Conclusions The astragalus polysaccharide and hirudin combined intervention in reducing lipid accumulation in macrophages is superior to drug treatment alone. The combined treatment of the two drugs can reduce the apoptosis rate of macrophages induced by ox-LDL. Its mechanism may be related to regulate mitochondrial membrane potential and regulate the expressions of proapoptotic protein Caspase-3, Bax and anti-apoptotic protein Bcl-2. [ABSTRACT FROM AUTHOR]

Background and Aim: The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin complex 1 (mTORC1) signaling pathway plays a crucial role in autophagy and inflammation. Our previous studies demonstrated that Shen-Yuan-Dan Capsule (SYDC), a Chinese medicine used for treating angina pectoris, has anti-atherosclerotic and anti-inflammatory effects in mice. However, its effects on autophagy and the PI3K/Akt/mTORC1 signaling pathway remain unclear. This study aimed to explore the effects of SYDC on autophagy and PI3K/Akt/mTORC1 signaling in the apolipoprotein E knockout (ApoE−/−) mouse model and in macrophage-derived foam cells to delineate the underlying mechanism. Methods: After 6 weeks of high-fat diet, ApoE–/– mice were randomly grouped into control, Lipitor, low-SYDC (SYDC-L), middle-SYDC (SYDC-M), and high-SYDC (SYDC-H) groups (n = 10). The mice were intragastrically administered the respective treatment for 6 weeks. Murine RAW264.7 cells were stimulated with oxidized low-density lipoprotein (ox-LDL) (80 µg/ml) for 24 h and then pretreated with SYDC freeze-dried powder for another 24 h. Cells treated with SYDC were co-cultured for 24 h with LY294002, tricirbine, and rapamycin to investigate the effects on the PI3K/Akt/mTORC1 signaling pathway. Results: SYDC ameliorated blood lipid levels, reduced the atherosclerotic index and plaque areas in the aortic root in mice, and inhibited total cholesterol (TC) levels and cholinesterase (ChE)/TC ratios in ox-LDL stimulated macrophages. Moreover, SYDC up-regulated Beclin1 and LC3II/I proteins in mice and in the ox-LDL–stimulated macrophages. Moreover, SYDC inhibited AKT phosphorylation at Ser473 and mTOR phosphorylation at Ser2448 in mice and in ox-LDL–stimulated macrophages. Furthermore, SYDC's inhibitory of ChE/TC ratios in ox-LDL–stimulated macrophages was not changed by selective inhibition of the PI3K/Akt/mTORC1 pathway. Conclusions: Our results highlight that SYDC treatment attenuates foam cell formation by promoting autophagy via inhibiting activation of the PI3K/Akt/mTORC1 signaling pathway. This study provides new insights into the molecular mechanism underlying SYDC's therapeutic potential for treating atherosclerosis. [ABSTRACT FROM AUTHOR]

Lipid metabolism dysregulation plays a crucial role in the occurrence of atherosclerosis (As). SCAP/SREBP signaling is the main pathway for regulating lipid metabolism. Tetramethylpyrazine (TMP), a Traditional Chinese Medicine (TCM) for treating angina pectoris, has antiatherosclerotic effects and ameliorates blood lipids disturbance. However, its precise mechanism remains unclear. This study investigated the mechanism of TMP in ameliorating As in mice model. After six weeks of high-fat diet, 30 ApoE−/− mice were randomized (n=10) and treated with Lipitor, TMP, or distilled water for six weeks. The serum blood lipids and insulin levels were measured. The expressions of PAQR3, Insig-1, SCAP, SREBP-1c, IRS-1, PI3K, Akt, and mTORC-1 in the adipose tissues were determined. The results showed that TMP could significantly decrease blood lipids levels, insulin, and corrected plaque area of the ApoE−/− mice as compared to the untreated mice (P<0.05, P<0.01). Moreover, TMP could significantly downregulate the expressions of SCAP, SREBP-1c, PAQR3, IRS-1, PI3K, Akt, and mTORC1 (P<0.01). Thus, TMP may ameliorate lipid metabolism disorder and As by downregulating PAQR3 and inhibiting SCAP/SREBP-1c signaling pathway. In addition, PI3K/Akt/mTORC1 signaling pathway may be involved in this process. [ABSTRACT FROM AUTHOR]

Background: Renalase is a protein that can regulate sympathetic nerve activity by metabolizing catecholamines, while redundant catecholamines are thought to contribute to atherosclerosis (As). Catecholamine release can be facilitated by angiotensin (Ang) II by binding to Ang II type 1 (AT1) receptors. Valsartan, a special AT1 antagonist, can dilate blood vessels and reduce blood pressure, but it remained unclear whether valsartan can promote the stability of atherosclerotic plaque by affecting renalase. Objective: This study examined the tissue distribution of renalase in ApoE−/− mice fed with a high-fat diet and the effect of valsartan on expression of renalase. Methods: ApoE−/− mice were fed with a high-fat diet for 13 or 26 weeks. As a control, 10 C57BL mice were fed with a standard chow diet. After 13 weeks on the high-fat diet, the ApoE−/− mice were randomized (10 mice/group) and treated with valsartan, simvastatin, or distilled water (control group) for an additional 13 weeks accompanied by a high-fat diet. Results: Knockout of ApoE caused a dramatic increase in expression of renalase in mice adipose tissue. With the disturbance of lipid metabolism induced by a high-fat diet, renalase expression decreased in the liver. Renalase can be expressed in smooth muscle cells and M2 macrophages in atherosclerotic plaque, and its expression gradually decreases in the fibrous cap during the transition from stable to vulnerable atherosclerotic plaque. Valsartan, an AT1 receptor antagonist, promotes the stabilization of atherosclerotic plaque by increasing the levels of renalase in serum and the expression of renalase in the fibrous cap of atherosclerotic plaque. It also reduces triglyceride levels in serum and increases the expression of renalase in the liver. Conclusions: Renalase may be a potential-related gene of lipid metabolism and As, and it may be the possible molecular target of valsartan to help stabilize atherosclerotic plaque. [ABSTRACT FROM AUTHOR]