A novel rabbit model of atherosclerotic vulnerable plaque established by cryofluid-induced endothelial injury.

Acute thrombosis secondary to atherosclerotic plaque rupture is the main cause of acute cardiac and cerebral ischemia. An animal model of unstable atherosclerotic plaques is highly important for investigating the mechanism of plaque rupture and thrombosis. However, current animal models involve complex operations, are costly, and have plaque morphologies that are different from those of humans. We aimed to establish a simple animal model of vulnerable plaques similar to those of humans. Rabbits were randomly divided into three groups. Group A was given a normal formula diet for 13 weeks. Group C underwent surgery on the intima of the right carotid artery with - 80 °C cryofluid-induced injury after 1 week of a high-fat diet and further feeding a 12-week high-fat diet. Group B underwent the same procedure as Group C but without the - 80 °C cryofluid. Serum lipid levels were detected via ELISA. The plaque morphology, stability and degree of stenosis were evaluated through hematoxylin-eosin (HE) staining, Masson trichrome staining, Elastica van Gieson staining (EVG), and oil red O staining. Macrophages and inflammatory factors in the plaques were assessed via immunohistochemical analysis. The serum low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), and total cholesterol (TC) levels in groups B and C were significantly greater than those in group A. No plaque formation was observed in group A. The plaques in group B were very small. In group C, obvious plaques were observed in the blood vessels, and the plaques exhibited a thin fibrous cap, a large lipid core, and partially visible neovascularization, which is consistent with the characteristics of vulnerable plaques. In the plaques of group C, a large number of macrophages were present, and matrix metalloproteinase 9 (MMP-9) and lectin-like oxidized LDL receptor 1 (LOX-1) were abundantly expressed. We successfully established a rabbit model of vulnerable carotid plaque similar to that of humans through the combination of cryofluid-induced endothelial injury and a high-fat diet, which is feasible and cost effective.

Macrophage mediators and mechanisms in cardiovascular disease.

Macrophages are major players in myocardial infarction (MI) and atherosclerosis, two major cardiovascular diseases (CVD). Atherosclerosis is caused by the buildup of cholesterol-rich lipoproteins in blood vessels, causing inflammation, vascular injury, and plaque formation. Plaque rupture or erosion can cause thrombus formation resulting in inadequate blood flow to the heart muscle and MI. Inflammation, particularly driven by macrophages, plays a central role in both atherosclerosis and MI. Recent integrative approaches of single-cell analysis-based classifications in both murine and human atherosclerosis as well as experimental MI showed overlap in origin, diversity, and function of macrophages in the aorta and the heart. We here discuss differences and communalities between macrophages in the heart and aorta at steady state and in atherosclerosis or upon MI. We focus on markers, mediators, and functional states of macrophage subpopulations. Recent trials testing anti-inflammatory agents show a major benefit in reducing the inflammatory burden of CVD patients, but highlight a necessity for a broader understanding of immune cell ontogeny and heterogeneity in CVD. The novel insights into macrophage biology in CVD represent exciting opportunities for the development of novel treatment strategies against CVD.

Carotid intima-media thickness and atherosclerotic plaques are associated with renal function decline: a 14-year longitudinal population-based study.

BACKGROUND: Chronic kidney disease (CKD) leads to increased morbidity and mortality. The underlying causes of CKD are often similar to those of atherosclerosis. We investigated whether carotid atherosclerotic parameters are associated with renal function decline. METHODS: Within the population-based Study of Health in Pomerania (SHIP), Germany, 2904 subjects were observed over 14 years. The carotid intima-media thickness (cIMT) as well as carotid plaques were measured by standardized B-mode ultrasound protocol. CKD is defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 and albuminuria as urinary albumin-creatinine ratio (ACR) ≥30 mg/g. eGFR was calculated by the full age spectrum (FAS) equation and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Mixed models were applied to associate carotid parameters with change in renal function longitudinally and adjusted for confounding. RESULTS: The age range of the study sample was 25-86 years with a median of 54 years at baseline. In longitudinal analyses, subjects with high cIMT and the presence of plaques at baseline showed a greater decrease in eGFR (cIMT: FAS-eGFR: P < .001, CKD-EPI-eGFR: P < .001; plaques: FAS-eGFR: P < .001, CKD-EPI-eGFR: n.s.) as well as an increased risk of developing CKD during the follow-up (cIMT: FAS-eGFR: P = .001, CKD-EPI-eGFR: P = .04; plaques: FAS-eGFR: P = .008, CKD-EPI-eGFR: P = .001). There was no association between atherosclerotic parameters and the risk of developing albuminuria. CONCLUSIONS: cIMT and carotid plaques are associated with renal function decline as well as CKD in a population-based sample. Furthermore, the FAS equation adapts best to this study population.

Regulation of cells of the arterial wall by hypoxia and its role in the development of atherosclerosis.

The cell's response to hypoxia depends on stabilization of the hypoxia-inducible factor 1 complex and transactivation of nuclear factor kappa-B (NF-κB). HIF target gene transcription in cells resident to atherosclerotic lesions adjoins a complex interplay of cytokines and mediators of inflammation affecting cholesterol uptake, migration, and inflammation. Maladaptive activation of the HIF-pathway and transactivation of nuclear factor kappa-B causes monocytes to invade early atherosclerotic lesions, maintaining inflammation and aggravating a low-oxygen environment. Meanwhile HIF-dependent upregulation of the ATP-binding cassette transporter ABCA1 causes attenuation of cholesterol efflux and ultimately macrophages becoming foam cells. Hypoxia facilitates neovascularization by upregulation of vascular endothelial growth factor (VEGF) secreted by endothelial cells and vascular smooth muscle cells lining the arterial wall destabilizing the plaque. HIF-knockout animal models and inhibitor studies were able to show beneficial effects on atherogenesis by counteracting the HIF-pathway in the cell wall. In this review the authors elaborate on the up-to-date literature on regulation of cells of the arterial wall through activation of HIF-1α and its effect on atherosclerotic plaque formation.

The Assessment of Carotid Atherosclerotic Plaque among Young Patients with Familial Hypercholesterolemia.

Objective Few data exist regarding when atherosclerotic changes occur among patients with familial hypercholesterolemia (FH). Carotid ultrasonography is a non-invasive method of evaluating this issue. The present study (1) compared the clinical utilities of carotid intima-media thickness (cIMT) and carotid plaque score (cPS) and (2) estimated the onset and progression of carotid atherosclerosis among patients with heterozygous FH (HeFH). Methods We retrospectively analyzed 511 patients under 30 years old who underwent carotid ultrasonography at our hospital from 2006 to 2019. We classified them into the HeFH group (n=78, 21.4±5.9 years old) and non-FH group (n=433, 23.4±6.0 years old) based on the clinical diagnosis and compared their cIMT and cPS values. In addition, we estimated the onset and progression of carotid atherosclerosis among young HeFH patients. Results There was no significant difference in the cIMT between the HeFH and non-FH groups (0.44 mm vs. 0.42 mm, p=0.25). In contrast, the cPS was significantly higher in the HeFH group than in the non-FH group (1.11 vs. 0.26, p=0.002). The regression equation for cPS of HeFH group was Y=-2.05+0.15X (r=0.37, p<0.001). Conclusion An assessment based on the cPS rather than the cIMT appears to be better to capture the progress of carotid atherosclerosis among young HeFH patients. Carotid atherosclerosis may start to develop at 14 years old in patients with HeFH.

Relationship between annular calcification of plaques in the carotid sinus and perioperative hemodynamic disorder in carotid angioplasty and stenting.

OBJECTIVE: To investigate the correlation between annular plaque calcification in the carotid sinus and perioperative hemodynamic disorder (HD) in carotid angioplasty and stenting (CAS). METHODS: The clinical data of 49 patients undergoing CAS due to narrowing of the carotid sinus were retrospectively analyzed. All patients had preoperative carotid computed tomography angiography (CTA) and were divided into HD and non-HD groups based on the occurrence of HD in the perioperative period of CAS. HD was defined as persistent bradycardia (heart rate < 60 beats per min) or persistent hypotension (systolic blood pressure < 90 mmHg) in the perioperative period and lasting for at least 1 h. The baseline data, including the degree of carotid artery stenosis, plaque length, plaque thickness, calcified plaque morphologies (i.e., plaque circumferential angle: < 90° defined as dotted calcification; 90°-180° defined as arcuate calcification; > 180° defined as annular calcification), contralateral carotid artery conditions, balloon diameter, and stent types, were compared between the two groups. Binary logistic regression was used to analyze the risk factors for the occurrence of HD. RESULTS: Among the 49 patients undergoing CAS, 14 (28.57%) developed perioperative HD, and 35 did not. Annular calcification was more common in the patients in the HD group than in the non-HD group. No significant differences in the probabilities of dotted and arcuate calcifications were found between the two groups (p > 0.05). The duration of continuous dopamine consumption in the HD group was 9-71 h. The average hospital stay of the HD group (10.14 ± 4.17 days) was significantly longer than that of the non-HD group (6.57 ± 1.9 days; p < 0.001). Patients in the HD group had significantly more pronounced lumen stenosis (p = 0.033) and longer plaque length (p = 0.034) than those in the non-HD group. After adjusting for age and sex, multivariate regression analysis showed that the presence of annular plaque calcification was an independent predictor of HD (odds ratio: 7.68, 95% confidence interval: 1.46-40.37, p = 0.016). CONCLUSIONS: The occurrence of annular plaque calcification in the carotid sinus was an independent risk factor for perioperative HD in CAS. Preoperative carotid CTA assists with the early identification of high-risk patients who may develop HD.

Interleukin-6 Predicts Carotid Plaque Severity, Vulnerability, and Progression.

BACKGROUND: IL-6 (interleukin-6) has important roles in atherosclerosis pathophysiology. To determine if anti-IL-6 therapy warrants evaluation as an adjuvant stroke prevention strategy in patients with carotid atherosclerosis, we tested whether circulating IL-6 levels predict carotid plaque severity, vulnerability, and progression in the prospective population-based CHS (Cardiovascular Health Study). METHODS: Duplex carotid ultrasound was performed at baseline and 5 years. Baseline plaque severity was scored 0 to 5 based on North American Symptomatic Carotid Endarterectomy Trial grade of stenosis. Plaque vulnerability at baseline was the presence of markedly irregular, ulcerated, or echolucent plaques. Plaque progression at 5 years was a ≥1 point increase in stenosis severity. The relationship of baseline plasma IL-6 levels with plaque characteristics was modeled using multivariable linear (severity) or logistic (vulnerability and progression) regression. Risk factors of atherosclerosis were included as independent variables. Stepwise backward elimination was used with P>0.05 for variable removal. To assess model stability, we computed the E-value or minimum strength of association (odds ratio scale) that unmeasured confounders must have with log IL-6 and the outcome to suppress the association. We performed internal validation with 100 bootstrap samples. RESULTS: There were 4334 participants with complete data (58.9% women, mean age: 72.7±5.1 years), including 1267 (29.2%) with vulnerable plaque and 1474 (34.0%) with plaque progression. Log IL-6 predicted plaque severity (ß=0.09, P=1.3×10-3), vulnerability (OR, 1.21 [95% CI, 1.05-1.40]; P=7.4×10-3, E-value=1.71), and progression (OR, 1.44 [95% CI, 1.23-1.69], P=9.1×10-6, E-value 2.24). In participants with >50% predicted probability of progression, mean log IL-6 was 0.54 corresponding to 2.0 pg/mL. Dichotomizing IL-6 levels did not affect the performance of prediction models. CONCLUSIONS: Circulating IL-6 predicts carotid plaque severity, vulnerability, and progression. The 2.0 pg/mL cutoff could facilitate the selection of individuals that would benefit from anti-IL-6 drugs for stroke prevention.

Emerging Concepts of Vascular Cell Clonal Expansion in Atherosclerosis.

Clonal expansion is a process that can drive pathogenesis in human diseases, with atherosclerosis being a prominent example. Despite advances in understanding the etiology of atherosclerosis, clonality studies of vascular cells remain in an early stage. Recently, several paradigm-shifting preclinical studies have identified clonal expansion of progenitor cells in the vasculature in response to atherosclerosis. This review provides an overview of cell clonality in atherosclerotic progression, focusing particularly on smooth muscle cells and macrophages. We discuss key findings from the latest research that give insight into the mechanisms by which clonal expansion of vascular cells contributes to disease pathology. The further probing of these mechanisms will provide innovative directions for future progress in the understanding and therapy of atherosclerosis and its associated cardiovascular diseases.

Immunoglobulin E Sensitization to Mammalian Oligosaccharide Galactose-α-1,3 (α-Gal) Is Associated With Noncalcified Plaque, Obstructive Coronary Artery Disease, and ST-Segment-Elevated Myocardial Infarction.

BACKGROUND: Treating known risk factors for coronary artery disease (CAD) has substantially reduced CAD morbidity and mortality. However, a significant burden of CAD remains unexplained. Immunoglobulin E sensitization to mammalian oligosaccharide galactose-α-1,3-galactose (α-Gal) was recently associated with CAD in a small observational study. We sought to confirm that α-Gal sensitization is associated with CAD burden, in particular noncalcified plaque. Additionally, we sort to assess whether that α-Gal sensitization is associated with ST-segment-elevated myocardial infarction (STEMI) Methods: We performed a cross-sectional analysis of participants enrolled in the BioHEART cohort study. We measured α-Gal specific-immunoglobulin E antibodies in serum of 1056 patients referred for CT coronary angiography for suspected CAD and 100 selected patients presenting with STEMI, enriched for patients without standard modifiable risk factors. CT coronary angiograms were assessed using coronary artery calcium scores and segmental plaque scores. RESULTS: α-Gal sensitization was associated with presence of noncalcified plaque (odds ratio, 1.62 [95% CI, 1.04-2.53], P=0.03) and obstructive CAD (odds ratio, 2.05 [95% CI, 1.29-3.25], P=0.002), independent of age, sex, and traditional risk factors. The α-Gal sensitization rate was 12.8-fold higher in patients with STEMI compared with matched healthy controls and 2.2-fold higher in the patients with STEMI compared with matched stable CAD patients (17% versus 1.3%, P=0.01 and 20% versus 9%, P=0.03, respectively). CONCLUSIONS: α-Gal sensitization is independently associated with noncalcified plaque burden and obstructive CAD and occurs at higher frequency in patients with STEMI than those with stable or no CAD. These findings may have implications for individuals exposed to ticks, as well as public health policy. Registration: URL: https://www.anzctr.org.au; Unique identifier: ACTRN12618001322224.

Association of sedentary time and carotid atherosclerotic plaques in patients with type 2 diabetes.

BACKGROUND: Atherosclerosis is a common complication in patients with type 2 diabetes (T2DM). Multiple factors are involved in the development and progress of atherosclerosis. We evaluated the association of weekly sedentary time (WST) with carotid plaque formation. METHODS: After data cleaning, a total of 26 664 participants with T2DM from 10 National Metabolic Management Centers (MMCs) from June 2017 to April 2021 were enrolled. Self-reported lifestyle data including WST, sleeping time, smoking and drinking information, carotid artery ultrasound, and biochemical parameters were obtained. The independent association of carotid plaue with sedentary and other lifestyle behaviors was evaluated using multivariable logistic regression models, and odds ratio (OR) with 95% confidence interval (CI) were reported. Moreover, stratified analysis was conducted to demonstrate the influence of confounding factors. RESULTS: The mean (SD) age of the participants was 54.0 (11.6) years, and the median (interquartile range) WST was 35.0 (21.0, 42.0) h. Comparing with participants in the first tertile of WST, those in the second or third tertile of WST were younger and with a shorter duration of diabetes. There were positive associations between longer sedentary time and odds of artery plaque after adjustment, with corresponding ORs in the second and third tertile were 1.40 (95% CI: 1.31-1.50) and 1.67 (95% CI: 1.56-1.79), respectively. However, the effect of WST on plaque in patients aged 18-40 years old had no statistical significance; the p value in the third tertile was 0.163. CONCLUSIONS: In summary, higher WST appears to be associated with higher prevalence of carotid plaque in patients with T2DM, especially in aged populations.

High lipoprotein(a) is associated with major adverse limb events after femoral artery endarterectomy.

BACKGROUNDS AND AIMS: Elevated lipoprotein(a) (Lp[a]) has been identified as a causal risk factor for cardiovascular disease including peripheral arterial disease (PAD). Although Lp(a) is associated with the diagnosis of PAD, it remains elusive whether there is an association of Lp(a) with cardiovascular and limb events in patients with severe PAD. METHODS: Preoperative plasma Lp(a) levels were measured in 384 consecutive patients that underwent iliofemoral endarterectomy and were included in the Athero-Express biobank. Our primary objective was to assess the association of Lp(a) levels with Major Adverse Limb Events (MALE). Our secondary objective was to relate Lp(a) levels to Major Adverse Cardiovascular Events (MACE) and femoral plaque composition that was acquired from baseline surgery. RESULTS: During a median follow-up time of 5.6 years, a total of 225 MALE were recorded in 132 patients. Multivariable analysis, including history of peripheral intervention, age, diabetes mellitus, end stage renal disease and PAD disease stages, showed that Lp(a) was independently associated with first (HR of 1.36 (95% CI 1.02-1.82) p = .036) and recurrent MALE (HR 1.36 (95% CI 1.10-1.67) p = .004). A total of 99 MACE were recorded but Lp(a) levels were not associated with MACE.sLp(a) levels were significantly associated with a higher presence of smooth muscle cells in the femoral plaque, although this was not associated with MALE or MACE. CONCLUSIONS: Plasma Lp(a) is independently associated with first and consecutive MALE after iliofemoral endarterectomy. Hence, in patients who undergo iliofemoral endarterectomy, Lp(a) could be considered as a biomarker to enhance risk stratification for future MALE.

LncRNA HSPA7 in human atherosclerotic plaques sponges miR-223 and promotes the proinflammatory vascular smooth muscle cell transition.

Although there are many genetic loci in noncoding regions associated with vascular disease, studies on long noncoding RNAs (lncRNAs) discovered from human plaques that affect atherosclerosis have been highly limited. We aimed to identify and functionally validate a lncRNA using human atherosclerotic plaques. Human aortic samples were obtained from patients who underwent aortic surgery, and tissues were classified according to atherosclerotic plaques. RNA was extracted and analyzed for differentially expressed lncRNAs in plaques. Human aortic smooth muscle cells (HASMCs) were stimulated with oxidized low-density lipoprotein (oxLDL) to evaluate the effect of the identified lncRNA on the inflammatory transition of the cells. Among 380 RNAs differentially expressed between the plaque and control tissues, lncRNA HSPA7 was selected and confirmed to show upregulated expression upon oxLDL treatment. HSPA7 knockdown inhibited the migration of HASMCs and the secretion and expression of IL-1ß and IL-6; however, HSPA7 knockdown recovered the oxLDL-induced reduction in the expression of contractile markers. Although miR-223 inhibition promoted the activity of Nf-κB and the secretion of inflammatory proteins such as IL-1ß and IL-6, HSPA7 knockdown diminished these effects. The effects of miR-223 inhibition and HSPA7 knockdown were also found in THP-1 cell-derived macrophages. The impact of HSPA7 on miR-223 was mediated in an AGO2-dependent manner. HSPA7 is differentially increased in human atheroma and promotes the inflammatory transition of vascular smooth muscle cells by sponging miR-223. For the first time, this study elucidated the molecular mechanism of action of HSPA7, a lncRNA of previously unknown function, in humans.

SYNTAX and Coronary Artery Calcium Score Predict Atherosclerotic Plaque Formation in the Ascending Aorta.

BACKGROUND: There is no study about the relationship between the complexity of coronary artery disease (SYNTAX SCORE; SS), and coronary artery calcium (CAC) score, accompanied with aortic calcium score (ACS) levels. The objective of this study was to investigate the relationship between the preoperative SS and CAC scores accompanying ACS in isolated CABG patients and their postoperative clinical results. METHODS: This study included 130 consecutive CABG patients. The mean age of the patients was 62.3 ± 8.62 years (range: 47-84 years). SS was measured using coronary angiography by an experienced cardiologist. We investigated the ACS accompanied with CAC scores using a multidetector computed tomography (MDCT) in the same session, preoperatively. Measurements of the CAC score and ACS were measured by an experienced radiologist, who was unaware of the study in the same session. In order to investigate aortic wall pathology in patients with positive aortic calcification, we provided aortic tissue samples prior to the proximal anastomosis of bypass grafts using No:11 scalpel. RESULTS: Overall median SS was 39 ± 7.2 (range: 15-41). CAC score was zero in 34 patients (26.1%). For the patients with a CAC score of zero, the median SS was 32 ± 9.4. There was no evidence of aortic calcification or plaque formation in 62 patients (47.6%). In these patients, the median SS was 35.6 ± 11.3. No significant difference was found when both groups were compared and for those patients with a calcific score of zero (P = .85). The median CAC score and ACS were 238 ± 122 AU (range: 0-1238 AU) and 112 ± 40 AU (range: 0-730 AU), respectively (P = .0033). For patients with a CAC score and ACS ≥400 AU, the mean SYNTAX score was ≥ 37. SS was correlated with CAC score (R:0.585; P < .0001). SYNTAX was correlated with ACS (R:0.557; P < .001). In multivariate analysis of SS (OR 1.053, 95% CI: 1.003-1.106, P = .039), gender (OR 0.189, 95% CI: 0.053-0.678, P = 0.011), age (OR 1.454, 95% CI: 1.256-1.632, P = .012), and diabetes mellitus (OR 0.341, 95% CI: 1.006-1.124, P = .014) were independent predictors for CAC score and aortic calcification. CONCLUSIONS: CAC score and ACS are strongly correlated with the complexity of coronary arteries in CABG patients. The total CAC score (≥ 400 AU) was independently associated with the degree of SS (>37). To prevent MACCE and mortality in CABG patients, we suggest the measurement of CAC score accompanied with ACS using MDCT as a non-invasive method. Highlight points: • Atherosclerotic plaque formation in aorta and coronary arteries are the main risk factors for stroke and infarction in CABG operations. •SYNTAX score value and aortic atherosclerosis levels are directly correlated. •SYNTAX score may predict the complications due to atherosclerosis during heart surgery.

Trafficking of Mononuclear Phagocytes in Healthy Arteries and Atherosclerosis.

Monocytes and macrophages play essential roles in all stages of atherosclerosis - from early precursor lesions to advanced stages of the disease. Intima-resident macrophages are among the first cells to be confronted with the influx and retention of apolipoprotein B-containing lipoproteins at the onset of hypercholesterolemia and atherosclerosis development. In this review, we outline the trafficking of monocytes and macrophages in and out of the healthy aorta, as well as the adaptation of their migratory behaviour during hypercholesterolemia. Furthermore, we discuss the functional and ontogenetic composition of the aortic pool of mononuclear phagocytes and its link to the atherosclerotic disease process. The development of mouse models of atherosclerosis regression in recent years, has enabled scientists to investigate the behaviour of monocytes and macrophages during the resolution of atherosclerosis. Herein, we describe the dynamics of these mononuclear phagocytes upon cessation of hypercholesterolemia and how they contribute to the restoration of tissue homeostasis. The aim of this review is to provide an insight into the trafficking, fate and disease-relevant dynamics of monocytes and macrophages during atherosclerosis, and to highlight remaining questions. We focus on the results of rodent studies, as analysis of cellular fates requires experimental manipulations that cannot be performed in humans but point out findings that could be replicated in human tissues. Understanding of the biology of macrophages in atherosclerosis provides an important basis for the development of therapeutic strategies to limit lesion formation and promote plaque regression.

Cardiovascular morbidities in postoperative colorectal cancer patients.

This retrospective observational study investigated the long-term prevalence of new-onset cardiovascular disease (CVD) and the predictive role of atherosclerotic plaque in the aorta and iliac arteries for CVD in postoperative colorectal cancer (CRC) patients who received surgical treatment between 2014 and 2015. CVD included coronary or cerebrovascular diseases which required treatment and new-onset CVD included peri-and postoperatively diagnosed CVDs or aggravated CVDs that required additional treatment during follow-up. Of the 2,875 patients included in this study, the prevalence of CVD was 8.9% (255/2875) and 141 (4.9%) developed new-onset CVD. Maximum arterial stenosis in the aorta or iliac arteries occurred in 40.8 ± 18.6% of patients with new-onset CVD and 11.6 ± 13.8% of patients without new-onset CVD (p < 0.001). The mean new-onset CVD-free survival time in patients with > 30% and < 30% stenoses were 52.5 [95% confidence intervals (CIs) 50.0-54.9] and 66.5 (95% CIs 66.2-66.8) months, respectively (p < 0.001). The area under the receiver operating characteristic curve of the maximal arterial stenosis for new-onset CVD was 0.911. These results suggest that CRC patients are at risk for developing new-onset CVD, which is associated with reduced survival. Atherosclerotic burden in the aorta or both iliac arteries may help predict future CVD events.

SUR1-E1506K mutation impairs glucose tolerance and promotes vulnerable atherosclerotic plaque phenotype in hypercholesterolemic mice.

BACKGROUND AND AIMS: Diabetes is a major risk factor of atherosclerosis and its complications. The loss-of-function mutation E1506K in the sulfonylurea receptor 1 (SUR1-E1506K) induces hyperinsulinemia in infancy, leading to impaired glucose tolerance and increased risk of type 2 diabetes. In this study, we investigate the effect of SUR1-E1506K mutation on atherogenesis in hypercholesterolemic LDLR-/- mice. METHODS: SUR1-E1506K mutated mice were cross-bred with LDLR-/- mice (SUR1Δ/LDLR-/-), 6 months old mice were fed a western-diet (WD) for 6 months to induce advanced atherosclerotic plaques. At the age of 12 months, atherosclerosis and plaque morphology were analyzed and mRNA gene expression were measured from aortic sections and macrophages. Glucose metabolism was characterized before and after WD. Results were compared to age-matched LDLR-/- mice. RESULTS: Advanced atherosclerotic plaques did not differ in size between the two strains. However, in SUR1Δ/LDLR-/- mice, plaque necrotic area was increased and smooth muscle cell number was reduced, resulting in higher plaque vulnerability index in SUR1Δ/LDLR-/- mice compared to LDLR-/- mice. SUR1Δ/LDLR-/- mice exhibited impaired glucose tolerance and elevated fasting glucose after WD. The positive staining area of IL-1ß and NLRP3 inflammasome were increased in aortic sections in SUR1Δ/LDLR-/- mice compared to LDLR-/- mice, and IL-18 plasma level was elevated in SUR1Δ/LDLR-/- mice. Finally, the mRNA expression of IL-1ß and IL-18 were increased in SUR1Δ/LDLR-/- bone marrow derived macrophages in comparison to LDLR-/- macrophages in response to LPS. CONCLUSIONS: SUR1-E1506K mutation impairs glucose tolerance and increases arterial inflammation, which promotes a vulnerable atherosclerotic plaque phenotype in LDLR-/- mice.

MicroRNA-22 inhibition promotes the development of atherosclerosis via targeting interferon regulator factor 5.

Atherosclerosis is generally accepted as a chronic inflammatory disease and is the most important pathological process underlying the cardiovascular diseases. MiR-22 exerts an important role in tumorgenesis, obesity and NAFLD development, as well as cardiovascular diseases. However, a certain role of miR-22 in the pathogenesis of atherosclerosis remains undetermined. Here, we showed that miR-22 exhibited a negative association with the deteriorated atherosclerotic plaque and showed significant downregulated expression in macrophages. Next, treatment of ApoE deficiency (ApoE-/-) mice with miR-22 inhibitors which were then subjected to high fat diet (HFD) for 12 weeks were performed to investigate the function of miR-22 on atherogenesis. The results exhibited that miR-22 inhibition dramatically promoted atherosclerotic plaques but attenuated plaque stabilization which were accompanied by decreased smooth muscle cell and collagen content, but increased macrophage infiltration and lipid accumulation. More importantly, the in vivo and in vitro experiments suggested that miR-22 inhibition accelerated inflammatory response and foam cell formation. Mechanistically, we demonstrated interferon regulator factor 5 (IRF5) was an important target of miR-22 and it was required for the regulation of inflammation mediated by miR-22 inhibition. Collectively, these evidences revealed that miR-22 inhibition promoted the atherosclerosis progression through activation of IRF5.

Natural Killer T Cells Are Involved in Atherosclerotic Plaque Instability in Apolipoprotein-E Knockout Mice.

The infiltration and activation of macrophages as well as lymphocytes within atherosclerotic lesion contribute to the pathogenesis of plaque rupture. We have demonstrated that invariant natural killer T (iNKT) cells, a unique subset of T lymphocytes that recognize glycolipid antigens, play a crucial role in atherogenesis. However, it remained unclear whether iNKT cells are also involved in plaque instability. Apolipoprotein E (apoE) knockout mice were fed a standard diet (SD) or a high-fat diet (HFD) for 8 weeks. Moreover, the SD- and the HFD-fed mice were divided into two groups according to the intraperitoneal injection of α-galactosylceramide (αGC) that specifically activates iNKT cells or phosphate-buffered saline alone (PBS). ApoE/Jα18 double knockout mice, which lack iNKT cells, were also fed an SD or HFD. Plaque instability was assessed at the brachiocephalic artery by the histological analysis. In the HFD group, αGC significantly enhanced iNKT cell infiltration and exacerbated atherosclerotic plaque instability, whereas the depletion of iNKT cells attenuated plaque instability compared to PBS-treated mice. Real-time PCR analyses in the aortic tissues showed that αGC administration significantly increased expressional levels of inflammatory genes such as IFN-γ and MMP-2, while the depletion of iNKT cells attenuated these expression levels compared to those in the PBS-treated mice. Our findings suggested that iNKT cells are involved in the exacerbation of plaque instability via the activation of inflammatory cells and upregulation of MMP-2 in the vascular tissues.

Carotid Plaque Phenotyping by Correlating Plaque Morphology from Computed Tomography Angiography with Transcriptional Profiling.

OBJECTIVE: Ischaemic strokes can be caused by unstable carotid atherosclerosis, but methods for identification of high risk lesions are lacking. Carotid plaque morphology imaging using software for visualisation of plaque components in computed tomography angiography (CTA) may improve assessment of plaque phenotype and stroke risk, but it is unknown if such analyses also reflect the biological processes related to lesion stability. Here, we investigated how carotid plaque morphology by image analysis of CTA is associated with biological processes assessed by transcriptomic analyses of corresponding carotid endarterectomies (CEAs). METHODS: Carotid plaque morphology was assessed in patients undergoing CEA for symptomatic or asymptomatic carotid stenosis consecutively enrolled between 2006 and 2015. Computer based analyses of pre-operative CTA was performed to define calcification, lipid rich necrotic core (LRNC), intraplaque haemorrhage (IPH), matrix (MATX), and plaque burden. Plaque morphology was correlated with molecular profiles obtained from microarrays of corresponding CEAs and models were built to assess the ability of plaque morphology to predict symptomatology. RESULTS: Carotid plaques (n = 93) from symptomatic patients (n = 61) had significantly higher plaque burden and LRNC compared with plaques from asymptomatic patients (n = 32). Lesions selected from the transcriptomic cohort (n = 40) with high LRNC, IPH, MATX, or plaque burden were characterised by molecular signatures coupled with inflammation and extracellular matrix degradation, typically linked with instability. In contrast, highly calcified plaques had a molecular signature signifying stability with enrichment of profibrotic pathways and repressed inflammation. In a cross validated prediction model for symptoms, plaque morphology by CTA alone was superior to the degree of stenosis. CONCLUSION: The study demonstrates that CTA image analysis for evaluation of carotid plaque morphology, also reflects prevalent biological processes relevant for assessment of plaque phenotype. The results support the use of CTA image analysis of plaque morphology for risk stratification and management of patients with carotid stenosis.

CISD1 protects against atherosclerosis by suppressing lipid accumulation and inflammation via mediating Drp1.

Atherosclerosis still remains the leading cause of morbidity and mortality worldwide, and deeper understanding of target signaling that protect from the atherosclerosis progression may provide novel therapeutic strategies. CDGSH iron-sulfur domain-containing protein 1 (CISD1) is a protein localized on the outer membrane of mitochondria, and plays key roles in regulating cell death and oxidative stress. However, its potential on atherosclerosis development and the underlying mechanisms are largely unknown. Here, in our study, we found markedly decreased CISD1 expression in lipid-laden THP1 macrophages. Notably, lentivirus (LV)-mediated CISD1 over-expression remarkably ameliorated lipid deposition in macrophages stimulated by ox-LDL. Furthermore, cellular total ROS and mitochondrial ROS generation, and impairment of mitochondrial membrane potential (MMP) were highly induced by ox-LDL in THP1 cells, while being considerably reversed upon CISD1 over-expression. Inflammatory response caused by ox-LDL was also significantly restrained in macrophages with CISD1 over-expression. Mechanistically, we found that CISD1 could interact with dynamin-related protein 1 (Drp1). Intriguingly, CISD1-improved mitochondrial dysfunction and inflammation in ox-LDL-treated macrophages were strongly abolished by Drp1 over-expression, indicating that Drp1 suppression might be necessary for CISD1 to perform its protective effects in vitro. In high fat diet (HFD)-fed apolipoprotein E-deficient (ApoE-/-) mice, tail vein injection of lentiviral vector expressing CISD1 remarkably decreased atherosclerotic lesion area, serum LDL cholesterol levels and triglyceride contents. Inflammatory response, cellular total and mitochondrial ROS production, and Drp1 expression levels in aorta tissues were also dramatically ameliorated in HFD-fed ApoE-/- mice, contributing to the inhibition of atherosclerosis in vivo. Therefore, improving CISD1 expression may be a novel therapeutic strategy for atherosclerosis treatment.