Isoliquiritigenin regulated ox-LDL through activating the PPAR-γ signaling pathway to stabilize atherosclerosis plaques

Objective:To explore the molecular mechanisms of isoliquiritigenin in stabilizing atherosclerotic plaques by activating PPAR-γsignal pathway to regulate ox-LDL metabolism.Methods:The ApoE-/-mice AS carotid plaque model was prepared by using high fat diet and right perivascular carotid collar placement(PCCP).ApoE-/-mice were randomly divided into the model group and the isoliquiritigenin group after PCCP.C57BL/6J mice were used for the control group.High fat diet continued feeding for 8 weeks after PCCP to establish the AS model.Automatic biochemical analyzer was used to test levels of total cholesterol(TC),triacylglyceride(TG),low-density lipoprotein cholesterol(LDL-C)and high-density lipoprotein cholesterol(HDL-C).ELISA was used to measure oxidized low-density lipoprotein(ox-LDL)in serum.Hematoxylin-eosin(HE)staining was used to observe the pathological pattern of the carotid artery,and then calculated the carotid parameters.Oil red O staining was used for lipid determination,Masson staining was used to determine collagen content,MOMA-2 andα-SMA immunohistochemical staining were used to determine macrophages and smooth muscle cells,and to calculate the vulnerability index.Western blot was used to detected the expression of PPAR-γ,LXR-α,FABP-4,MMP-2 and MMP-9 in mice arteries.Results:Compared with the normal group,TC、TG、LDL-C、HDL-C and ox-LDL were increased in the model group.Compared with the model group,TC、TG、LDL-C and ox-LDL were reduced,and there was no significant change in HDL-C of the isoliquiritigenin group.Compared with the normal group,intima thickness(IT),intima/media thickness(IT/MT),plaque area(PA),and plaque area/lumen area(PA/LA)of carotid arteries were increased,the content of lipid and MOMA-2 in plaques was increased,collagen andα-SMA content decreased,and the vulnerability index was higher in the model group.The expression of PPAR-γand LXR-αwere reduced and the expression of FABP-4,MMP-2 and MMP-9 were increased in the model group.Compared with the model group,carotid IT,IT/MT,PA,and PA/LA were reduced,the content of lipid and MOMA-2 in plaques was decreased,collagen andα-SMA content were increased,and the vulnerability index was decreased in the isoliquiritigenin group.PPAR-γand LXR-αexpression were increased,FABP-4,MMP-2 and MMP-9 expression were decreased significantly in the isoliquiritigenin group.Conclusion:Isoliquiritigenin can exert anti-AS effects by activating PPAR-γ,up-regulating LXR-α,reducing FABP-4 expression,reducing ox-LDL,reducing the protein expression of MMP-2 and MMP-9,decreasing plaque vulnerability index,and increasing plaque stability.

Clinical study on the correlation between plasma lipopolysaccharide and the structural characteristics of coronary intravascular ultrasound plaques

Objective:To study the correlation between plasma lipopolysaccharide and coronary atherosclerotic heart disease risk factors and plaque stability.Methods:136 patients with unstable angina pectoris who underwent coronary angiography and intravascular ultrasound were selected from the First Affiliated Hospital of Guangxi University of Traditional Chinese Medicine.According to the results of IVUS,they were divided into stable plaques(stable plaques,SP)group of 72 patients With 64 cases in the Unstable plaques(UP)group,venous blood was drawn from the two groups of patients for blood lipid and lipopolysaccharide index detection,and the general baseline data of the two groups were recorded;the structural characteristics of the intravascular ultrasound plaques in the two groups were analyzed.To study the influencing factors of unstable plaques,the correlation between lipopolysaccharide and plaque structural characteristics,and the diagnostic efficacy of unstable plaques.Results:The expression levels of cholesterol,low-density lipoprotein,and LPS in the UP group were higher than those in the SP group(P<0.05),and the high-density lipoprotein expression levels were lower than those in the SP group(P=0.035);and the intravascular ultrasound structure of the plaque was UP The lipid pool area,the ratio of lipid pool to plaque area,the plaque eccentricity index,and the maximum plaque thickness of the group were higher than those of the SP group(P<0.05),and the minimum plaque thickness was smaller than that of the SP group and the difference was statistically significant(P<0.05);LPS was positively correlated with cholesterol,low-density lipoprotein,lipid pool area,ratio of lipid pool to plaque area,plaque eccentricity index,and maximum plaque thickness by Pearson correlation test(P<0.05),Is negatively correlated with high-density lipoprotein(P=0.021);LPS is a risk factor for coronary plaque stability,and HDL is a protective factor for coronary plaque stability by binary logistic regression test.The difference is statistically significant Scientific significance(P=0.049,P=0.002);LPS diagnosis of coronary atherosclerotic plaque stability ROC area under the curve(AUC)is 0.889,95%CI is(0.805,0.974),the best diagnosis point is 57.485 mg/L,the sensitivity is 80.60%,and the specificity is 73.70%.Conclusion:Plasma lipopolysaccharide is a risk factor of unstable plaque,which has certain diagnostic value for coronary artery plaque,and can be used as a quantitative diagnostic index of plaque vulnerability.

Mechanism of Chronic Stress-induced Reduced Atherosclerotic Medial Area and Increased Plaque Instability in Rabbit Models of Chronic Stress

Background： Chronic stress contributes to increased risks ofatherosclerotic diseases including heart disease, stroke, and transient ischemic attack. However, its underline mechanisms are poorly understood. This study aimed to elucidate the mechanism via which chronic stress exerts its effect on atherosclerosis （AS）. Methods： Fifty male New Zealand white rabbits were used. Aortic balloon-injury model was applied. Both social stress and physical stress methods were adopted to establish chronic stress models. The lumen stenotic degree, intimal and medial areas, maximum fibrous cap thickness, and plaque contents were measured with histological sections. Proteomic methods were applied to detect protein changes in abdominal aortas to identify the specialized mediators. Real-time reverse transcription-polymerase chain reaction was used for further verification and investigation. Results： The stress rabbits exhibited lower body weight, worse fur state, more inactivity behavior, and higher serum cortisol level. Chronic stress was significantly associated with the decreased medial area and increased plaque instability, which was manifested by thinner fibrous caps, larger lipid cores, more macrophages, and new vessels but fewer smooth muscle cells and elastic fibers. After chronic stress, the apoptosis-related genes UBE2K, BAX, b）~S, Ca.v^ase 3, Caspase 9, and P53 were upregulated, and B^Z-2/BAX was down-regulated; the angiogenesis-related genes ANG and VEGF-A were also highly expressed in atherosclerotic arteries. Conclusions： Rabbit models of chronic stress were successfully established by applying both social stress and physical stress for 8 weeks. Chronic stress can reduce AS tunica media and accelerate plaque instability by promoting apoptosis and neovascularization.

p-Cresyl sulfate promotes the formation of atherosclerotic lesions and induces plaque instability by targeting vascular smooth muscle cells

Coronary atherosclerosis is a major complication of chronic kidney disease. This condition contributes to the increased mortality in dialysis patients.p-Cresyl sulfate （PCS） is a prototype of protein-bound uremic toxins that cannot be efficiently removed through routine dialysis procedures. In the present study, ApoE/- mice that underwent 5/6 nephrectomy were randomly divided into two groups, namely, vehicle-treated group （n = 20） and PCS-treated group （n = 20）. Mice were sacrificed for en face and immunohistological analyses after 8 or 24 weeks of high-fat diet. Rat aortic vascular smooth muscle cells （VSMCs） were treated with phosphate buffer solution or 500 ltmol/L PCS for in vitro evaluation. PCS-treated mice were observed to suffer increased atherosclerotic lesions after eight weeks of PCS administration. Moreover, 24 weeks of PCS administration also markedly increased the vulnerability index of aortic plaques. PCS was also observed to facilitate the migration and proliferation of VSMCs during the progression of the disease. Moreover, PCS disturbed the balance between matrix metalloproteinases and tissue inhibitor of metalloproteinases within the plaques. Thus, PCS played a vital role in promoting atherogenesis and disturbing the stability of formed plaques probably by targeting VSMCs.

The“two-pronged”nanosystem to precisely improve lipid metabolism and inflammatory microenvironment for atherosclerotic plaque stabilization

The rupture of atherosclerosis(AS)vulnerable plaque is the major cause of fatal arterial thrombosis related diseases.The lipid dysbolism and pro-inflammatory microenvironment are considered two main driving factors for plaque rupture.Herein,a“two-pronged”nanosystem LCS-Se/Res was designed to efficiently stabilize AS plaques,by precisely regulating lipid metabolism and inflammatory microenvironment.LCS-Se/Res was constructed with the core of resveratrol(Res)loaded selenium(Se)nanoparticles(NPs),and the shell(LCS)of targeting peptide(LSIPPKA)modified chitosan(CS).This system was stable in blood circulation.When it arrived at the plaque site,LCS-Se/Res could actively recognize the highly expressed lectin-like oxidized low-density lipoprotein receptor 1(LOX-1)receptor and accumulate there.Thereafter,Res was released from LCS-Se nanocarriers in situ by responding to acidic plaque microenvironment.On the one hand,Res increased autophagy flux in damaged endothelial cells by activating cAMP-PKA-AMPK-SIRT1 signaling pathway to promote lipid degradation.Interestingly,LCS-Se also promoted cholesterol efflux to improve lipid metabolism.On the other hand,fixed-point separated Res and LCS-Se synergistically improved plaque inflammatory microenvironment by reversing macrophage phenotype(M1 to M2)and alleviating plaque oxidative stress.Pharmacodynamics result proved that the plaque vulnerability index(VI)decreased from 1.39±0.282 to 0.108±0.02 after LCS-Se/Res treatment.In short,this study provided a new therapeutic strategy for the atherosclerosis through the two-pronged approach.

Effect of Removing Toxic Substances Combined with Activating Blood Circulation on Stabilizing the Atherosclerotic Plaque and Unstable Angina

The therapeutic effects of activating blood circulation to remove stasis of Chinese medicine （CM） in the prevention and treatment of atherosclerotic diseases such as coronary artery disease and angina are generally acknowledged. In recent years, to further improve the therapeutic effects of those Chinese herbs on such diseases, we have carried out a series of studies of CM medications with the function of clearing heat and removing toxic substances combined with activating blood circulation to remove stasis.

Pathogenic role of microRNAs in atherosclerotic ischemic stroke:Implications for diagnosis and therapy

Ischemic stroke resulting from atherosclerosis(particularly in the carotid artery)is one of the major subtypes of stroke and has a high incidence of death.Disordered lipid homeostasis,lipid deposition,local macrophage infiltration,smooth muscle cell proliferation,and plaque rupture are the main pathological processes of atherosclerotic ischemic stroke.Hepatocytes,macrophages,endothelial cells and vascular smooth muscle cells are the main cell types participating in these processes.By inhibiting the expression of the target genes in these cells,microRNAs play a key role in regulating lipid disorders and atherosclerotic ischemic stroke.In this article,we listed the microRNAs implicated in the pathology of atherosclerotic ischemic stroke and aimed to explain their pro-or antiatherosclerotic roles.Our article provides an update on the potential diagnostic use of miRNAs for detecting growing plaques and impending clinical events.Finally,we provide a perspective on the therapeutic use of local microRNA delivery and discuss the challenges for this potential therapy.

Red Yeast Rice Prevents Atherosclerosis through Regulating Inflammatory Signaling Pathways

Objective： To observe the effects of red yeast rice（RYR） on blood lipid levels, aortic atherosclerosis（AS）, and plaque stability in apolipoprotein E gene knockout（Apo E-/-） mice. Methods： Twentyfour Apo E-/-mice were fed with a high-fat diet starting from 6 weeks of age. Mice were randomized into three groups（n = 8 in each group）： model group（Apo E-/-group）, RYR group（Apo E-/-＋ RYR group）, and simvastatin group（Apo E-/-＋ simvastatin group）. Eight 6-week-old C57BL/6 mice were assigned as the control group and fed with a basic diet. After 36 weeks, plasma lipids and inflammatory factors were measured. Aortic atherosclerotic lesions by microscope, scanning electron microscope and transmission electron microscope were observed. Plasma levels of interleukin-6（IL-6） and tumor necrosis factor-α（TNF-α） were measured with enzymelinked immunosorbent assay. The level of high sensitivity C-reaction protein（Hs-CRP） was detected by the scattering immunoturbidimetric assay. Protein expression of matrix metalloproteinase-9（MMP-9） and nuclear factor κB（NF-κB） in aorta were tested by immunohistochemistry. Results： Compared with the model group, treatment with RYR significantly decreased the levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, lipoprotein（a）, and apolipoprotein B100 in Apo E-/-mice（P〈0.01）. Compared with the model group, treatment with RYR decreased the levels of Hs-CRP, IL-6, and TNF-α（P〈0.01）. RYR also reduced the protein levels of NF-κB and MMP-9 of the aorta. Conclusions： RYR has the anti-atherosclerotic and stabilizing unstable plaque effects. The mechanism might be related to the inflammatory signaling pathways.