Computed Tomography of Aortic Wall Calcifications in Aortic Dissection Patients

Objectives

To investigate the frequency of aortic calcifications at the outer edge of the false lumen and the frequency of fully circular aortic calcifications in a consecutive series of patients with aortic dissection who underwent contrast-enhanced CT.

Methods

The study population compromised of 69 consecutive subjects aged 60 years and older with a contrast-enhanced CT scan demonstrating an aortic dissection. All CT scans were evaluated for the frequency of aortic calcifications at the outer edge of the false lumen and the frequency of fully circular aortic calcifications by two experienced observers. Between observer reliability was evaluated by using Cohen’s Kappa. Differences between groups were tested using unpaired T test and Chi-square test.

Results

Presumed media calcifications were observed in 22 (32%) patients of 60 years and older and were found more frequently in chronic aortic dissection (N = 12/23, 52%) than in acute aortic dissection (N = 10/46, 22%).

Conclusion

As the intima has been torn away by the aortic dissection it is highly likely that CT scans can visualize the calcifications in the tunica media of the aorta.     

A genetic investigation of Korean mummies from the Joseon Dynasty

Two Korean mummies (Danwoong-mirra and Yoon-mirra) found in medieval tombs in the central region of the Korean peninsula were genetically investigated by analysis of mitochondrial DNA (mtDNA), Y-chromosomal short tandem repeat (Y-STR) and the ABO gene. Danwoong-mirra is a male child mummy and Yoon-mirra is a pregnant female mummy, dating back about 550 and 450 years, respectively. DNA was extracted from soft tissues or bones. mtDNA, Y-STR and the ABO gene were amplified using a small size amplicon strategy and were analyzed according to the criteria of ancient DNA analysis to ensure that authentic DNA typing results were obtained from these ancient samples. Analysis of mtDNA hypervariable region sequence and coding region single nucleotide polymorphism (SNP) information revealed that Danwoong-mirra and Yoon-mirra belong to the East Asian mtDNA haplogroups D4 and M7c, respectively. The Y-STRs were analyzed in the male child mummy (Danwoong-mirra) using the AmpFlSTR^® Yfiler^TM PCR Amplification Kit and an in-house Y-miniplex plus system, and could be characterized in 4 loci with small amplicon size. The analysis of ABO gene SNPs using multiplex single base extension methods revealed that the ABO blood types of Danwoong-mirra and Yoon-mirra are AO01 and AB, respectively. The small size amplicon strategy and the authentication process in the present study will be effectively applicable to future genetic analyses of various forensic and ancient samples.     

Uptake of Aortic 18F-FDG Is Correlated with Low-Density Lipoprotein Cholesterol and Leptin in a General Population

Objective

This study investigated the relationship between aortic ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) uptake and clinical and laboratory findings related to atherosclerosis in a general population.

Methods

¹⁸F-FDG uptake in the ascending aorta was measured on the positron emission tomography/computed tomography (PET/CT) scans of 211 Japanese adults. The maximum target-to-background ratio (TBR) was compared with clinical and laboratory atherosclerosis findings.

Results

By multivariate regression analysis adjusted for age and sex, TBR-ascending aorta (TBR-A) was significantly correlated with various clinical and laboratory parameters, such as body mass index, log visceral fat area, low-density lipoprotein cholesterol (LDL-C), log fasting immunoreactive insulin, log homeostasis model assessment of insulin resistance, log total adiponectin and log-leptin, in all subjects. Furthermore, by multivariate linear regression analysis adjusted for confounding factors, TBR-A was significantly correlated with LDL-C (β = 0.001, p = 0.03) and log-leptin (β = 0.336, p<0.01) in all subjects.

Conclusion

TBR-A was significantly correlated with LDL-C and log-leptin independent from confounding factors. Our results suggest that aortic ¹⁸F-FDG uptake is a good marker of atherosclerosis, even in a general population.     

Increased Arterial PET/CT 18F-Fluorodeoxyglucose Uptake in Obese and Overweight Patients

ObjectivesWe aimed to investigate the association between BMI and early atherosclerotic activity in cancer patients. We also compared the inflammatory and macroscopic calcification processes of atherosclerosis in the aortic segments and large arteries by ¹⁸F-FDG PET/CT of between normal and high BMI patients.MethodsWe conducted a retrospective review of cancer patients presented to our institution within the period between February and May 2018. Patients were classified according to their BMI into two groups: normal BMI group and high BMI group. Data of average SUVmax and SUVmean for four segments of the aorta, common iliac arteries, and femoral arteries were estimated and compared between both groups. Moreover, the macroscopic calcification on CT images for each vascular section was also reported.ResultsNinety-eight patients were classified into two groups: normal BMI group (n = 52; 53.1%), and high BMI group (n = 46; 46.9%). Average SUVmax was significantly higher in obese participants in all arterial segments (P < 0.05). However, the SUVmean was significantly higher in obese patients in only three arterial segments aortic arch, left femoral artery and descending thoracic aorta (P < 0.05).Moreover, the differences between the two study groups in terms of the frequency of macroscopic calcifications were not statistically significant for all vascular segments. BMI positively correlated with SUVmax and SUVmean of the vascular segments (r value from 0,219 to 0,575/p value between 0,023 and 0,0001).ConclusionsFluorine-18-FDG PET/CT imaging revealed that patients with high BMI have more accelerated atherosclerotic inflammatory process in their major vessels compared to their age-matched controls with normal BMI. Future studies should assess the associated between these findings and the cardiovascular events in the long term.     

Fusobacterium nucleatum Alters Atherosclerosis Risk Factors and Enhances Inflammatory Markers with an Atheroprotective Immune Response in ApoEnull Mice

The American Heart Association supports an association between periodontal disease (PD) and atherosclerotic vascular disease (ASVD) but does not as of yet support a causal relationship. Recently, we have shown that major periodontal pathogens Porphyromonas gingivalis and Treponema denticola are causally associated with acceleration of aortic atherosclerosis in ApoE^null hyperlipidemic mice. The aim of this study was to determine if oral infection with another significant periodontal pathogen Fusobacterium nucleatum can accelerate aortic inflammation and atherosclerosis in the aortic artery of ApoE^null mice. ApoE^null mice (n = 23) were orally infected with F. nucleatum ATCC 49256 and euthanized at 12 and 24 weeks. Periodontal disease assessments including F. nucleatum oral colonization, gingival inflammation, immune response, intrabony defects, and alveolar bone resorption were evaluated. Systemic organs were evaluated for infection, aortic sections were examined for atherosclerosis, and inflammatory markers were measured. Chronic oral infection established F. nucleatum colonization in the oral cavity, induced significant humoral IgG (P=0.0001) and IgM (P=0.001) antibody response (12 and 24 weeks), and resulted in significant (P=0.0001) alveolar bone resorption and intrabony defects. F. nucleatum genomic DNA was detected in systemic organs (heart, aorta, liver, kidney, lung) indicating bacteremia. Aortic atherosclerotic plaque area was measured and showed a local inflammatory infiltrate revealed the presence of F4/80⁺ macrophages and CD3⁺ T cells. Vascular inflammation was detected by enhanced systemic cytokines (CD30L, IL-4, IL-12), oxidized LDL and serum amyloid A, as well as altered serum lipid profile (cholesterol, triglycerides, chylomicrons, VLDL, LDL, HDL), in infected mice and altered aortic gene expression in infected mice. Despite evidence for systemic infection in several organs and modulation of known atherosclerosis risk factors, aortic atherosclerotic lesions were significantly reduced after F. nucleatum infection suggesting a potential protective function for this member of the oral microbiota.     

Detection of a Tumor Suppressor Gene Variant Predisposing to Colorectal Cancer in an 18th Century Hungarian Mummy

Mutations of the Adenomatous polyposis coli (APC) gene are common and strongly associated with the development of colorectal adenomas and carcinomas. While extensively studied in modern populations, reports on visceral tumors in ancient populations are scarce. To the best of our knowledge, genetic characterization of mutations associated with colorectal cancer in ancient specimens has not yet been described. In this study we have sequenced hotspots for mutations in the APC gene isolated from 18^th century naturally preserved human Hungarian mummies. While wild type APC sequences were found in two mummies, we discovered the E1317Q missense mutation, known to be a colorectal cancer predisposing mutation, in a large intestine tissue of an 18^th century mummy. Our data suggests that this genetic predisposition to cancer already existed in the pre-industrialization era. This study calls for similar investigations of ancient specimens from different periods and geographical locations to be conducted and shared for the purpose of obtaining a larger scale analysis that will shed light on past cancer epidemiology and on cancer evolution.     

Calcifications of the Thoracic Aorta on Extended Non-Contrast-Enhanced Cardiac CT

Background

The presence of calcified atherosclerosis in different vascular beds has been associated with a higher risk of mortality. Thoracic aorta calcium (TAC) can be assessed from computed tomography (CT) scans, originally aimed at coronary artery calcium (CAC) assessment. CAC screening improves cardiovascular risk prediction, beyond standard risk assessment, whereas TAC performance remains controversial. However, the curvilinear portion of the thoracic aorta (TA), that includes the aortic arch, is systematically excluded from TAC analysis. We investigated the prevalence and spatial distribution of TAC all along the TA, to see how those segments that remain invisible in standard TA evaluation were affected.

Methods and Results

A total of 970 patients (77% men) underwent extended non-contrast cardiac CT scans including the aortic arch. An automated algorithm was designed to extract the vessel centerline and to estimate the vessel diameter in perpendicular planes. Then, calcifications were quantified using the Agatston score and associated with the corresponding thoracic aorta segment. The aortic arch and the proximal descending aorta, “invisible” in routine CAC screening, appeared as two vulnerable sites concentrating 60% of almost 11000 calcifications. The aortic arch was the most affected segment per cm length. Using the extended measurement method, TAC prevalence doubled from 31% to 64%, meaning that 52% of patients would escape detection with a standard scan. In a stratified analysis for CAC and/or TAC assessment, 111 subjects (46% women) were exclusively identified with the enlarged scan.

Conclusions

Calcium screening in the TA revealed that the aortic arch and the proximal descending aorta, hidden in standard TA evaluations, concentrated most of the calcifications. Middle-aged women were more prone to have calcifications in those hidden portions and became candidates for reclassification.     

Gut Microbiome of an 11th Century A.D. Pre-Columbian Andean Mummy

The process of natural mummification is a rare and unique process from which little is known about the resulting microbial community structure. In the present study, we characterized the microbiome of paleofeces, and ascending, transverse and descending colon of an 11^th century A.D. pre-Columbian Andean mummy by 16S rRNA gene high-throughput sequencing and metagenomics. Firmicutes were the most abundant bacterial group, with Clostridium spp. comprising up to 96.2% of the mummified gut, while Turicibacter spp. represented 89.2% of the bacteria identified in the paleofeces. Microbiome profile of the paleofeces was unique when compared to previously characterized coprolites that did not undergo natural mummification. We identified DNA sequences homologous to Clostridium botulinum, Trypanosoma cruzi and human papillomaviruses (HPVs). Unexpectedly, putative antibiotic-resistance genes including beta-lactamases, penicillin-binding proteins, resistance to fosfomycin, chloramphenicol, aminoglycosides, macrolides, sulfa, quinolones, tetracycline and vancomycin, and multi-drug transporters, were also identified. The presence of putative antibiotic-resistance genes suggests that resistance may not necessarily be associated with a selective pressure of antibiotics or contact with European cultures. Identification of pathogens and antibiotic-resistance genes in ancient human specimens will aid in the understanding of the evolution of pathogens as a way to treat and prevent diseases caused by bacteria, microbial eukaryotes and viruses.     

Hsa-miRNA-23a-3p promotes atherogenesis in a novel mouse model of atherosclerosis

Of the known regulators of atherosclerosis, miRNAs have been demonstrated to play critical roles in lipoprotein homeostasis and plaque formation. Here, we generated a novel animal model of atherosclerosis by knocking in LDLR^W483X in C57BL/6 mice, as the W483X mutation in LDLR is considered the most common newly identified pathogenic mutation in Chinese familial hypercholesterolemia (FH) individuals. Using the new in vivo mouse model combined with a well-established atherosclerotic in vitro human cell model, we identified a novel atherosclerosis-related miRNA, miR-23a-3p, by microarray analysis of mouse aortic tissue specimens and human aortic endothelial cells (HAECs). miR-23a-3p was consistently downregulated in both models, which was confirmed by qPCR. Bioinformatics analysis and further validation experiments revealed that the TNFα-induced protein 3 (TNFAIP3) gene was the key target of miR-23a-3p. The miR-23a-3p-related functional pathways were then analyzed in HAECs. Collectively, the present results suggest that miR-23a-3p regulates inflammatory and apoptotic pathways in atherogenesis by targeting TNFAIP3 through the NF-κB and p38/MAPK signaling pathways.     

The Guanine-Nucleotide Exchange Factor SGEF Plays a Crucial Role in the Formation of Atherosclerosis

The passage of leukocytes across the endothelium and into arterial walls is a critical step in the development of atherosclerosis. Previously, we showed in vitro that the RhoG guanine nucleotide exchange factor SGEF (Arhgef26) contributes to the formation of ICAM-1-induced endothelial docking structures that facilitate leukocyte transendothelial migration. To further explore the in vivo role of this protein during inflammation, we generated SGEF-deficient mice. When crossed with ApoE null mice and fed a Western diet, mice lacking SGEF showed a significant decrease in the formation of atherosclerosis in multiple aortic areas. A fluorescent biosensor revealed local activation of RhoG around bead-clustered ICAM-1 in mouse aortic endothelial cells. Notably, this activation was decreased in cells from SGEF-deficient aortas compared to wild type. In addition, scanning electron microscopy of intimal surfaces of SGEF^−/− mouse aortas revealed reduced docking structures around beads that were coated with ICAM-1 antibody. Similarly, under conditions of flow, these beads adhered less stably to the luminal surface of carotid arteries from SGEF ^−/− mice. Taken together, these results show for the first time that a Rho-GEF, namely SGEF, contributes to the formation of atherosclerosis by promoting endothelial docking structures and thereby retention of leukocytes at athero-prone sites of inflammation experiencing high shear flow. SGEF may therefore provide a novel therapeutic target for inhibiting the development of atherosclerosis.     

Lipodystrophic gene Agpat2 deficiency aggravates hyperlipidemia and atherosclerosis in Ldlr−/− mice

AimsDysfunction of adipose tissue increases the risk of cardiovascular disease. It was well established that obesity aggravates atherosclerosis, but the effect of adipose tissue loss on atherosclerosis has been less studied. AGPAT2 is the first causative gene of congenital generalized lipodystrophy (CGL), but the role of AGPAT2 on atherosclerosis has not been reported. Hypertriglyceridemia is one of the clinical manifestations of CGL patients, but it is usually absent in CGL mouse model on a normal diet. This study will investigate the effect of Agpat2 on hyperlipidemia and atherosclerosis.Methods and resultsIn this study, Agpat2 knockout (Agpat2^−/−) mice were generated using CRISPR/Cas system, which showed severe loss of adipose tissue and fatty liver, consistent with previous reports. Agpat2^−/− mice were then crossed with hypercholesterolemic and atherosclerotic prone LDL receptor knockout (Ldlr^−/−) mice to obtain double knockout mouse model (Agpat2^−/−Ldlr^−/−). Plasma lipid profile, insulin resistance, fatty liver, and atherosclerotic lesions were observed after 12 weeks of the atherogenic high-fat diet (HFD) feeding. We found that compared with Ldlr^−/− mice, Agpat2^−/−Ldlr^−/− mice showed significantly higher plasma total cholesterol and triglycerides after HFD feeding. Agpat2^−/−Ldlr^−/− mice also developed hyperglycemia and hyperinsulinemia, with increased pancreatic islet area. The liver weight of Agpat2^−/−Ldlr^−/− mice was about 4 times higher than that of Ldlr^−/− mice. The liver lipid deposition was severe and Sirius red staining showed liver fibrosis. In addition, in Agpat2^−/−Ldlr^−/− mice, the area of atherosclerotic lesions in aortic arch and aortic root was significantly increased.ConclusionsOur results show that Agpat2 deficiency led to more severe hyperlipidemia, liver fibrosis and aggravation of atherosclerosis in Ldlr^−/− mice. This study provided additional insights into the role of adipose tissue in hyperlipidemia and atherosclerosis.     

Adenovirus-Mediated Prothymosin α Gene Transfer Inhibits the Development of Atherosclerosis in Apoe-Deficient Mice

Prothymosin α (ProT) is involved in regulating expression of the oxidative stress-protective genes and it also exerts immunomodulatory activities. In this study, we investigated the therapeutic effects of ProT gene transfer on atherosclerosis in endothelial cells and in ApoE-deficient mice. Adenoviruses encoding mouse ProT (AdProT) were used for the management of atherosclerosis. In vitro, the effects of ProT on antioxidant gene expressions and the protection effect against oxidant-mediated injury in endothelial cells were examined. In vivo, AdProT were administered intraventricularly into the heart of ApoE^-/- mice. Histopathological and immunohistochemical assessments of the aortic tissues were performed. Expressions of HO-1 and antioxidant genes in the aortic tissues were also determined. Our results demonstrated that ProT gene transfer increased antioxidant gene expressions, eNOS expression and NO release, as well as reduced the reactive oxygen species production in endothelial cells. Intraventricular administration of AdProT reduced the lesion formation, increased expressions of HO-1 and SOD genes, and reduced infiltrating macrophages in the aorta of ApoE^-/- mice. This study suggests that ProT gene transfer may have the therapeutic potential for the management of atherosclerosis via inducing antioxidant gene expressions, eNOS expression and NO release, reducing ROS production and macrophage infiltration in endothelium.     

Decreased expression of klotho gene in uremic atherosclerosis in apolipoprotein E-deficient mice

Chronic renal failure (CRF) markedly accelerates the development of atherosclerosis, but the pathogenesis of uremic atherosclerosis remains to be elucidated. The klotho gene, predominantly expressed in the kidney, plays a key role in regulating aging and the development of age-related diseases in mammals. A loss of klotho results in multiple aging-like phenotypes including atherosclerosis. This study examines the relationship between the klotho expression and the development of accelerated atherosclerosis in uremic state.Eight-week-old apolipoprotein E-deficient (apo-E^−/−) male mice underwent 5/6 partial kidney ablation to induce CRF or sham-operation. At 6 wk after nephrectomy, CRF mice showed significantly increased aortic plaque area fraction, aortic root plaque area and aortic cholesterol content as compared with non-CRF mice. Serum urea, total cholesterol and triglyceride concentrations were significantly higher in CRF apo-E^−/− mice compared with non-CRF controls. Moreover, the expression of renal klotho gene and the serum levels of klotho protein were markedly decreased in CRF mice compared with controls.These results suggested that CRF favored atherosclerosis in apo-E^−/− mice and uremic atherosclerosis was accompanied by down-regulation of klotho expression.     

Gremlin-1 Is an Inhibitor of Macrophage Migration Inhibitory Factor and Attenuates Atherosclerotic Plaque Growth in ApoE?/? Mice

Monocyte infiltration and macrophage formation are pivotal steps in atherosclerosis and plaque vulnerability. Gremlin-1/Drm is crucial in embryo-/organogenesis and has been shown to be expressed in the adult organism at sites of arterial injury and to inhibit monocyte migration. The purpose of the present study was to evaluate and characterize the role of Gremlin-1 in atherosclerosis. Here we report that Gremlin-1 is highly expressed primarily by monocytes/macrophages in aortic atherosclerotic lesions of ApoE^−/− mice and is secreted from activated monocytes and during macrophage development in vitro. Gremlin-1 reduces macrophage formation by inhibiting macrophage migration inhibitory factor (MIF), a cytokine critically involved in atherosclerotic plaque progression and vulnerability. Gremlin-1 binds with high affinity to MIF (K_D = 54 nm), as evidenced by surface plasmon resonance analysis and co-immunoprecipitation, and reduces MIF-induced release of TNF-α from macrophages. Treatment of ApoE^−/− mice with a dimeric recombinant fusion protein, _mGremlin1-Fc, but not with equimolar control Fc or inactivated _mGremlin1-Fc, reduced TNF-α expression, the content of monocytes/macrophages of atherosclerotic lesions, and attenuated atheroprogression. The present data disclose that Gremlin-1 is an endogenous antagonist of MIF and define a role for Gremlin-1/MIF interaction in atherosclerosis.     

Dennd5b-Deficient Mice are Resistant to PCSK9-Induced Hypercholesterolemia and Diet-Induced Hepatic Steatosis

Dennd5b plays a pivotal role in intestinal absorption of dietary lipids in mice and is associated with body mass index in humans. This study examined the impact of whole-body Dennd5b deletion on plasma lipid concentrations, atherosclerosis, and hepatic lipid metabolism in mice. Hypercholesterolemia was induced in Dennd5b^?/? mice by infection with an adeno-associated virus expressing the proprotein convertase subtilisin/kexin type 9 serine protease (PCSK9) gain-of-function mutation (PCSK9D377Y) and feeding a Western diet for 12 weeks. Body weight and plasma lipid concentrations were monitored over 12 weeks, and then aortic atherosclerosis and hepatic lipid content were quantified. Compared to Dennd5b^+/+ mice, Dennd5b^?/? mice were resistant to diet-induced weight gain and PCSK9-induced hypercholesterolemia. Atherosclerosis quantified by en face analysis and in aortic root sections, revealed significantly smaller lesions in Dennd5b^?/? compared to Dennd5b^+/+ mice. Additionally, Dennd5b^?/? mice had significantly less hepatic lipid content (triglyceride and cholesterol) compared to Dennd5b^+/+ mice. To gain insight into the basis for reduced hepatic lipids, quantitative PCR was used to measure mRNA abundance of genes involved in hepatic lipid metabolism. Key genes involved in hepatic lipid metabolism and lipid storage were differentially expressed in Dennd5b^?/? liver including Pparg, Cd36, and Pnpla3. These findings demonstrate a significant impact of Dennd5b on plasma and hepatic lipid concentrations and resistance to PCSK9-induced hypercholesterolemia in the absence of Dennd5b.     

Polymicrobial Infection with Major Periodontal Pathogens Induced Periodontal Disease and Aortic Atherosclerosis in Hyperlipidemic ApoEnull Mice

Periodontal disease (PD) and atherosclerosis are both polymicrobial and multifactorial and although observational studies supported the association, the causative relationship between these two diseases is not yet established. Polymicrobial infection-induced periodontal disease is postulated to accelerate atherosclerotic plaque growth by enhancing atherosclerotic risk factors of orally infected Apolipoprotein E deficient (ApoE^null) mice. At 16 weeks of infection, samples of blood, mandible, maxilla, aorta, heart, spleen, and liver were collected, analyzed for bacterial genomic DNA, immune response, inflammation, alveolar bone loss, serum inflammatory marker, atherosclerosis risk factors, and aortic atherosclerosis. PCR analysis of polymicrobial-infected (Porphyromonas gingivalis [P. gingivalis], Treponema denticola [T. denticola], and Tannerella forsythia [T. forsythia]) mice resulted in detection of bacterial genomic DNA in oral plaque samples indicating colonization of the oral cavity by all three species. Fluorescent in situ hybridization detected P. gingivalis and T. denticola within gingival tissues of infected mice and morphometric analysis showed an increase in palatal alveolar bone loss (p<0.0001) and intrabony defects suggesting development of periodontal disease in this model. Polymicrobial-infected mice also showed an increase in aortic plaque area (p<0.05) with macrophage accumulation, enhanced serum amyloid A, and increased serum cholesterol and triglycerides. A systemic infection was indicated by the detection of bacterial genomic DNA in the aorta and liver of infected mice and elevated levels of bacterial specific IgG antibodies (p<0.0001). This study was a unique effort to understand the effects of a polymicrobial infection with P. gingivalis, T. denticola and T. forsythia on periodontal disease and associated atherosclerosis in ApoE^null mice.     

A volumetric method for quantifying atherosclerosis in mice by using microCT: comparison to en face

Precise quantification of atherosclerotic plaque in preclinical models of atherosclerosis requires the volumetric assessment of the lesion(s) while maintaining in situ architecture. Here we use micro-computed tomography (microCT) to detect ex vivo aortic plaque established in three dyslipidemic mouse models of atherosclerosis. All three models lack the low-density lipoprotein receptor (Ldlr^−/−), each differing in plaque severity, allowing the evaluation of different plaque volumes using microCT technology. From clearly identified lesions in the thoracic aorta from each model, we were able to determine plaque volume (0.04–3.1 mm³), intimal surface area (0.5–30 mm²), and maximum plaque (intimal-medial) thickness (0.1–0.7 mm). Further, quantification of aortic volume allowed calculation of vessel occlusion by the plaque. To validate microCT for future preclinical studies, we compared microCT data to intimal surface area (by using en face methodology). Both plaque surface area and plaque volume were in excellent correlation between microCT assessment and en face surface area (r² = 0.99, p<0.0001 and r² = 0.95, p<0.0001, respectively). MicroCT also identified internal characteristics of the lipid core and fibrous cap, which were confirmed pathologically as Stary type III-V lesions. These data validate the use of microCT technology to provide a more exact empirical measure of ex vivo plaque volume throughout the entire intact aorta in situ for the quantification of atherosclerosis in preclinical models.     

Critical role of caspase-1 in vascular inflammation and development of atherosclerosis in Western diet-fed apolipoprotein E-deficient mice

ObjectiveRecent investigations have suggested that the inflammasome plays a role in the development of vascular inflammation and atherosclerosis; however, its precise role remains controversial. We produced double-deficient mice for apolipoprotien E (Apoe) and caspase-1 (Casp1), a key component molecule of the inflammasome, and investigated the effect of caspase-1 deficiency on vascular inflammation and atherosclerosis.Methods and resultsAtherosclerotic plaque areas in whole aortas and aortic root of Western diet (WD)-fed Apoe^?/?Casp1^?/? mice were significantly reduced compared to those in Apoe^?/? mice. The amount of macrophages and vascular smooth muscle cells in the plaques was also reduced in Apoe^?/?Casp1^?/? mice. No significant differences in plasma lipid profiles and body weight change were observed between these mice. Expression of interleukin (IL)-1β in the plaques as well as plasma levels of IL-1β, IL-1α, IL-6, CCL2, and TNF-α, in Apoe^?/?Casp1^?/? mice were lower than those in Apoe^?/? mice. In vitro experiments showed that calcium phosphate crystals induced caspase-1 activation and secretion of IL-1β and IL-1α in macrophages.ConclusionOur findings suggest that caspase-1 plays a critical role in vascular inflammation and atherosclerosis, and that modulation of caspase-1 could be a potential target for prevention and treatment of atherosclerosis.