Plaque Inflammation Research Articles

Clinical Evaluation of High-Resolution MRI Combined With DWI in Identifying Vulnerable Carotid Plaque.

High-resolution magnetic resonance imaging combined with diffusion weighted imaging is used to identify vulnerable plaques (VP) and their characteristic components, and apparent diffusion coefficient (ADC) correlation analysis with serum inflammatory markers to assess plaque vulnerability. In this study, 60 eligible patients were included, including 29 patients in VP group and 31 patients in non-VP group (N group). The average ADC value, serum inflammatory marker levels (high-sensitivity C-reactive protein, myeloperoxidase, and erythrocyte sedimentation rate) of the 2 groups were measured, and the characteristics of different plaque components and ADC levels of vascular wall in VP group were compared, to evaluate the correlation between serum inflammatory markers and the mean value of plaque ADC. The results showed that the ADC mean value of the plaques in the VP group was significantly lower than that in the N group, and the levels of hypersensitive C-reactive protein and myeloperoxidase were correlated with the ADC mean value of the plaques. The ADC value of plaque measured by high-resolution magnetic resonance imaging combined with diffusion weighted imaging sequence can quantify the identification of VP and its characteristic components, reflect the inflammation of plaque to a certain extent, and thus prevent and treat stroke and other adverse outcomes more effectively.

M1/M2 re-polarization of kaempferol biomimetic NPs in anti-inflammatory therapy of atherosclerosis.

Atherosclerosis (AS), a leading cause of death worldwide, involves chronic macrophage inflammation from its initiation to the emergence of complications. Targeting plaque inflammation by re-polarizing pro-inflammatory M1 to anti-inflammatory M2 could therefore provide a promising strategy to treat AS, but currently available anti-inflammatory drugs limit clinical outcomes. In this study, we found that kaempferol (KPF) is capable of potential anti-inflammation as a novel drug candidate, which has been scarcely reported. Building upon these findings, we fabricated a macrophage-biomimetic KPF delivery platform, abbreviated as KPF@MM-NPs to potentiate therapeutic payloads, wherein the designed ROS-responsive Dextran-g-PBMEO NPs with π-π stacking were coated with macrophage membrane (MM) for effective target and accumulation in atherosclerotic lesions. Therapy of KPF@MM-NPs afforded significant decrease in proliferating macrophage inflammation while went with the reduction of key pro-inflammatory cytokines and re-polarization M1 to M2 phenotype, inducing excellent anti-AS responses in ApoE-/- mice after i.p. delivery. The mechanism of KPF@MM-NPs was further investigated and found it related to block the ROS/NF-κB signaling pathways. Together with as well demonstrated biosafety profiles, this proof-of-concept opens an instructive door for the study of KPF-mediated nanodrugs in treatment of AS based on biomimetic NPs.

Retracted: Ultrasonic Imaging of Carotid Inflammatory Plaque with Superparamagnetic Nanoparticles.

[This retracts the article DOI: 10.1155/2021/9685660.].

Active Leptospermum Honey as a Local Drug Delivery Agent in patients with Chronic Periodontitis: A Clinico-Biochemical Study

Background: Antibacterial agents have always been the part and parcel in the treatment of periodontal infection. One such known agent is Active Leptospermum Honey (ALH) which has been the most studied species of medical grade honey used for the treatment of wounds and burns. Therefore, this study revolves around evaluating the efficacy of active leptospermum honey as a local drug delivery (LDD) agent on probing pocket depth (PPD), relative attachment level (RAL), and periodontal pocket pH. Materials and Methods: Based on the study's inclusion and exclusion criteria, a total of 100 sites with probing pocket depth of ≥ 5mm in posterior region will be selected. The sites will be grouped as: Test Group: 50 sites, Control Group: 50 sites, following the assessment of baseline clinical and biochemical parameters. At the baseline appointment, each patient received full mouth scaling and root planning (SRP). They were called back after 48 hours. Following the assessment of biochemical parameters by using pH test paper strips, MEDIHONEY® was placed as a local drug delivery (LDD) agent in test sites. In control sites only SRP was done. Patients were recalled after 30 days following LDD to reassess only gingival index, plaque index and biochemical parameters. Patients were recalled at 90 days following LDD for the reassessment of all clinical and biochemical parameters. Results: Plaque and gingival inflammation reduced in both groups but test group showed more reduction. Pocket depths were reduced significantly in test site. There was significant pH reduction in test sites. Clinical attachment level was also seen to be improved in the sites which were tested. Conclusion: When administered locally, Active Leptospermum Honey demonstrated lessening of PPD, gingival index (GI), and plaque index (PI), as well as higher levels of clinical attachment (CA).

Penatalaksanaan altered passive eruption dengan crown lenghtening (Laporan Kasus)

Aesthetic treatments related to the perfect smile are important in contemporary clinical dentistry. The disharmony of the smile, often called the gummy smile, can be caused by vertical maxillary growth, dentoalveolar extrusion, short upper lip, hyperactivity of the upper lip, altered passive eruption (APE), or a combination of such factors. Some studies mention the possibility of APE being a risk factor for periodontal disease. In some cases, excessive gingival can interfere with oral hygiene procedures and result in plaque accumulation and inflammation of the gingival margin. The management of APE is by periodontal crown lengthening surgery. The selection of the crown lengthening technique is adjusted to the classification, thickness, and number of keratinized gingiva, as well as the location of the cementoenamel junction (CEJ) or bone peak against the gingival margin.

Tuning macrophages for atherosclerosis treatment.

Atherosclerosis is a chronic inflammatory vascular disease and a leading cause of death worldwide. Macrophages play an important role in inflammatory responses, cell-cell communications, plaque growth and plaque rupture in atherosclerotic lesions. Here, we review the sources, functions and complex phenotypes of macrophages in the progression of atherosclerosis, and discuss the recent approaches in modulating macrophage phenotype and autophagy for atherosclerosis treatment. We then focus on the drug delivery strategies that target macrophages or use macrophage membrane-coated particles to deliver therapeutics to the lesion sites. These biomaterial-based approaches that target, modulate or engineer macrophages have broad applications for disease therapies and tissue regeneration.

Deleting interleukin-10 from myeloid cells exacerbates atherosclerosis in Apoe-/- mice.

Atherosclerosis is initiated by subendothelial retention of lipoproteins and cholesterol, which triggers a non-resolving inflammatory process that over time leads to plaque progression in the artery wall. Myeloid cells and in particular macrophages are the primary drivers of the inflammatory response and plaque formation. Several immune cells including macrophages, T cells and B cells secrete the anti-inflammatory cytokine IL-10, known to be essential for the atherosclerosis protection. The cellular source of IL-10 in natural atherosclerosis progression is unknown. This study aimed to determine the main IL10-producing cell type in atherosclerosis. To do so, we crossed VertX mice, in which IRES-green fluorescent protein (eGFP) was placed downstream of exon 5 of the Il10 gene, with atherosclerosis-prone Apoe-/- mice. We found that myeloid cells express high levels of IL-10 in VertX Apoe-/- mice in both chow and western-diet fed mice. By single cell RNA sequencing and flow cytometry analysis, we identified resident and inflammatory macrophages in atherosclerotic plaques as the main IL-10 producers. To address whether IL-10 secreted by myeloid cells is essential for the protection, we utilized LyzMCre+Il10fl/fl mice crossed into the Apoe-/- background and confirmed that macrophages were unable to secrete IL-10. Chow and western diet-fed LyzMCre+Il10fl/fl Apoe-/- mice developed significantly larger atherosclerotic plaques as measured by en face morphometry than LyzMCre-Il10 fl/flApoe-/-. Flow cytometry and cytokine measurements suggest that the depletion of IL-10 in myeloid cells increases Th17 cells with elevated CCL2, and TNFα in blood plasma. We conclude that macrophage-derived IL-10 is critical for limiting atherosclerosis in mice.

Translational Molecular Imaging Tool of Vulnerable Carotid Plaque: Evaluate Effects of Statin Therapy on Plaque Inflammation and American Heart Association–Defined Risk Levels in Cuff-Implanted Apolipoprotein E–Deficient Mice

Identification of high-risk carotid plaques in asymptomatic patients remains a challenging but crucial step in stroke prevention. The challenge is to accurately monitor the development of high-risk carotid plaques and promptly identify patients, who are unresponsive to best medical therapy, and hence targeted for carotid surgical interventions to prevent stroke. Inflammation is a key operator in destabilisation of plaques prior to clinical sequelae. Currently, there is a lack of imaging tool in routine clinical practice, which allows assessment of inflammatory activity within the atherosclerotic plaque. Herein, we have used a periarterial cuff to generate a progressive carotid atherosclerosis model in apolipoprotein E–deficient mice. This model produced clinically relevant plaques with different levels of risk, fulfilling American Heart Association (AHA) classification, at specific timepoints and locations, along the same carotid artery. Exploiting this platform, we have developed smart molecular magnetic resonance imaging (MRI) probes consisting of dual-targeted microparticles of iron oxide (DT-MPIO) against VCAM-1 and P-selectin, to evaluate the anti-inflammatory effect of statin therapy on progressive carotid atherosclerosis. We demonstrated that in vivo DT-MPIO-enhanced MRI can (i) quantitatively track plaque inflammation from early to advanced stage; (ii) identify and characterise high-risk inflamed, vulnerable plaques; and (iii) monitor the response to statin therapy longitudinally. Moreover, this molecular imaging–defined therapeutic response was validated using AHA classification of human plaques, a clinically relevant parameter, approximating the clinical translation of this tool. Further development and translation of this molecular imaging tool into the clinical arena may potentially facilitate more accurate risk stratification, permitting timely identification of the high-risk patients for prophylactic carotid intervention, affording early opportunities for stroke prevention in the future.

LAG3 Regulates T Cell Activation and Plaque Infiltration in Atherosclerotic Mice

BackgroundThe immune checkpoint receptor lymphocyte-activation gene 3 (LAG3) is a new target for immune checkpoint blockade (ICB), but the effects of LAG3 on atherosclerosis are not known. ObjectivesThe aim of the study was to evaluate the role of LAG3 on plaque inflammation using murine hypercholesterolemic models of atherosclerosis. MethodsTo study the role of LAG3 in atherosclerosis, we investigated both bone marrow chimeras lacking LAG3 in hematopoietic cells as well as global Lag3-/- knockout mice. Effects of anti-LAG3 monoclonal antibody monotherapy and combination therapy with anti-programmed cell death protein 1 (PD-1) were tested in hypercholesterolemic low-density lipoprotein receptor knockout (Ldlr-/-) mice and evaluated by histology and flow cytometry. ResultsLAG3-deficiency or treatment with blocking anti-LAG3 monoclonal antibodies led to increased levels of both interferon gamma–producing T helper 1 cells and effector/memory T cells, balanced by increased levels of regulatory T cells. Plaque size was affected by neither LAG3 deficiency nor LAG3 blockade, although density of T cells in plaques was 2-fold increased by loss of LAG3. Combination therapy of anti-PD-1 and anti-LAG3 had an additive effect on T cell activation and cytokine production and promoted plaque infiltration of T cells. ConclusionsLoss of LAG3 function promoted T cell activation and accumulation in plaques while not affecting plaque burden. Our report supports further clinical studies investigating cardiovascular risk in patients treated with anti-LAG3 ICB.

The use of anterior segment optical coherence tomography in infectious keratitis

AbstractPurpose: To describe the anterior segment optical coherence tomography (AS OCT) findings in infectious keratitis.Methods: Forty‐five patients with confirmed microbial keratitis were included in this prospective, observational case series study. All subjects underwent ophthalmologic examination. AS OCT scanning was performed on presentation and at follow‐up.Results: 25 patients (55%) had microbial keratitis, 18 patients (40%) had herpetic keratitis and Two patients (4%) had Fungal keratitis. Twelve different patterns were identified. Thirty‐two of the 45 eyes (71%) had epithelial defect associated with sub‐epithelial infiltrates in twenty cases (44%). In 13 of these cases, hydropic changes were observed. Thirty‐six eyes (80%) showed stromal involvement. Stromal infiltrates were also seen, in twenty cases, as a diffuse or local hyper‐reflective area. Five cases (11%) were associated with uveitis: Retrocorneal hyperreflective deposits, thick inflammatory plaque attached to the endothelium and anterior chamber inflammatory cells were imaged.Conclusions: Infectious keratitis has characteristic features on AS‐OCT images. These patterns are not specific and do not orient towards the nature of the microorganisms but AS‐OCT imaging may provide useful supplementary information for diagnosing and monitoring infectious keratitis.

Sex Differences in Carotid Atherosclerosis: A Systematic Review and Meta-Analysis.

Over the last decades, several individual studies on sex differences in carotid atherosclerosis have been performed covering a wide range of plaque characteristics and including different populations. This systematic review and meta-analysis aims to summarize previously reported results on sex differences in carotid atherosclerosis and present a roadmap explaining next steps needed for implementing this knowledge in clinical practice. We systematically searched PubMed, Embase, Web of Science, Cochrane Central, and Google Scholar for eligible studies including both male and female participants reporting prevalence of imaging characteristics of carotid atherosclerosis and meta-analyzed these studies. Studies had to report at least the following: (1) calcifications; (2) lipid-rich necrotic core; (3) intraplaque hemorrhage; (4) thin-or-ruptured fibrous cap; (5) plaque ulceration; (6) degree of stenosis; (7) plaque size; or (8) plaque inflammation. We prespecified which imaging modalities had to be used per plaque characteristic and excluded ultrasonography. We included 42 articles in our meta-analyses (ranging from 2 through 23 articles per plaque characteristic). Men had more frequently a larger plaque compared to women and, moreover, had more often plaques with calcifications (odds ratio=1.57 [95% CI, 1.23-2.02]), lipid-rich necrotic core (odds ratio=1.87 [95% CI, 1.36-2.57]), and intraplaque hemorrhage (odds ratio=2.52 [95% CI, 1.74-3.66]), or an ulcerated plaque (1.81 [95% CI, 1.30-2.51]). Furthermore, we found more pronounced sex differences for lipid-rich necrotic core in symptomatic opposed to asymptomatic participants. In this systematic review and meta-analysis, we demonstrate convincing evidence for sex differences in carotid atherosclerosis. All kinds of plaque features-plaque size, composition, and morphology-were more common or larger in men compared to women. Our results highlight that sex is an important variable to include in both study design and clinical-decision making. Further investigation of sex-specific stroke risks with regard to plaque composition is warranted.

Abstract 14622: Macrophage Dectin-1 Targeted Photoactivation Promotes Inflammation Resolution With Stabilization of the High-Risk Atheroma as Serially Assessed by Intravascular OCT-NIRF Imaging

Backgrounds: Atherosclerosis is a chronic inflammatory disease causing a fatal plaque rupture and its key aspect is a failure to resolve inflammation. We hypothesized that macrophage targeted near-infrared fluorescence (NIRF) emitting photoactivation could simultaneously in vivo assess the inflamed high-risk plaques and facilitate the inflammation resolution. Method and results: We newly synthesized a Dectin-1 targeted photoactivatable theranostic agent by the chemical conjugation of photosensitizer chlorin e6 (Ce6) and Dectin-1 ligand laminarin (LAM-Ce6). Intravascular photoactivation through a customized fiber-based diffuser effectively reduced inflammation in the targeted plaques 4 weeks after LAM-Ce6 administration as serially assessed by dual-modal optical coherence tomography (OCT)-NIRF catheter imaging. The number of TUNEL-positive apoptotic macrophages peaked at 1 day after laser irradiation, and then resolved until 4 weeks. One hour after the light therapy, autophagy was strongly augmented with the formation of autophagolysosomes revealed by co-localization of enhanced microtubule-associated protein light-chain 3 (LC3) and lysosome-associated membrane protein 2 (LAMP2) expressions in the plaques (Figure). LAM-Ce6 photoactivation increased the TUNEL/RAM11- and MerTK-positive cells in the plaques, suggestive of enhanced efferocytosis. In line with inflammation resolution, photoactivation reduced the plaque burden with collagen-rich fibrotic replacement via TGF-β pathway confirmed by corroborative immunostainings ( p <0.01). Conclusions: OCT-NIRF imaging-guided macrophage Dectin-1 targetable photoactivation could stabilize the inflamed high-risk plaques by autophagy-mediated inflammation resolution and TGF-β dependent fibrotic replacement. This novel targeted photoactivation will offer new opportunity for the catheter based theranostic strategy.

Abstract 15480: Liraglutide Inhibits Atherosclerotic Plaque Progression in Rabbits Through the Downregulation of Multiple Inflammatory and Metabolic Pathways

Background: Liraglutide, a GLP-1- receptor agonists approved for the treatment of type 2 diabetes and obesity confers a lower CVD mortality. However, mechanisms underlying this finding remain unknown, particularly in normoglycemic subjects. We investigated the effects of liraglutide on the progression and pathobiology of atherosclerosis using multimodal intravascular imaging in rabbits. Methods: Rabbits atherosclerosis (N=16) were induced by balloon injury of the abdominal aorta and cholesterol feeding for 6 weeks. Then, rabbits were imaged with intravascular ultrasound (IVUS) and near-infrared fluorescence optical coherence tomography (NIRF-OCT) for the analysis of plaque burden and plaque inflammation (ProSense VM110 NIRF agent, 4 mg/kg/iv) respectively. Next, rabbits were randomized into: Control (n=8) or liraglutide (n=8, 0.1 mg/kg/day) groups. Imaging was repeated after 4 weeks, followed by histopathology and RNA analysis. On per-slice basis (every 0.4 mm) of IVUS imaging, the percent atheroma volume (PAV) was measured across the 40 mm balloon injured area. Atheroma progression was quantified as the ΔPAV between 6 and 10 weeks. Results: IVUS analyses (3200 slices/16 rabbits) revealed that liraglutide significantly reduced plaque progression (ΔPAV, 1.5% [0.2-2.8] vs. 9.3% [6.7-13.0] control, p=0.05). In vivo distance-corrected VM110 cathepsin inflammatory plaque activity was similar (ΔNIRF average plaque 25.2 [-9.8- 62] vs. 22.6 [3.9- 52.5] nM control, p=0.72). Plaques from liraglutide-treated animals however exhibited fewer RAM11+ macrophages (21.3±11.4 vs. control 30.9±16.7 macrophages/section, p=0.01) stry. Both plaques showed similar αSMA (45.2±6.7% vs 52.4±1.2% αSMA+ area/section, p=0.327). Liraglutide decreased inflammatory RNA transcripts (IL-6 and TNF-α), and RNA-seq transcriptomic analysis revealed that liraglutide altered inflammatory and metabolic pathways (as CRP, CYP3A6, Apo-A4 and FMO3). Blood glucose was normal and similar between groups (p>0.05). Conclusion: Liraglutide suppresses in vivo atherosclerotic plaque progression and plaque macrophage expression in normoglycemic rabbits. Further investigation of its plaque stabilizing effects in subjects with and without diabetes is warranted.

Abstract 12286: A Novel Yap Inhibitor Cbl0137 Protects Against Endothelial Inflammation and Atherosclerosis

Background: Endothelial activation is a critical hallmark in the initiation of atherosclerosis. Our previous study found that YAP activation plays a significant role in induction of endothelial inflammation and formation of atherosclerotic plaques, suggesting that targeting YAP signaling pathway might be effective for the treatment of atherosclerotic cardiovascular disease. We have recently set up a reporter gene assay-based drug screening platform and identified CBL0137 as an inhibitor of YAP activity in human endothelial cells. Methods: We used 8*GTIIC luciferase reporter gene assay to screen a drug library and other small molecule compounds. We validated the inhibitory effect of CBL0137 on YAP activity by detecting the expression of YAP target genes and phosphorylation of YAP, which were measured by quantitative real-time polymerase chain reaction and western blotting, respectively. Subsequently, we treated human endothelial cells with CBL0137 (1 μM) for 4 hrs, and then isolated the total RNA and performed transcriptome sequencing. We explored the anti-inflammatory effects and underlying mechanisms of CBL0137 in primary endothelial cells. Moreover, we assessed whether CBL0137 could retard formation of atherosclerotic plaques in ApoE-/- mice using carotid artery partial ligation-induced and chronic western diet-induced atherosclerosis models. Results: We identified CBL0137 as a novel YAP inhibitor through screening the drug library. In human endothelial cells, CBL0137 inhibited the phosphorylation of YAP at Y357 to suppress YAP activity, and therefore repressed the expression of YAP target genes. In addition, CBL0137 restrained endothelial inflammatory response in a YAP-dependent manner. Furthermore, CBL0137 inhibited YAP phosphorylation at Y357 via the tyrosine-protein kinase Src. In animal experiments, administration of low doses of CBL0137 attenuated endothelial inflammation and atherosclerosis induced by disturbed flow or atherogenic diets in both male and female ApoE-/- mice. Conclusions: CBL0137 is a novel YAP inhibitor that protects against endothelial inflammation and atherogenesis. CBL0137 might be a promising anti-atherosclerosis drug, but further investigations including clinical trials are required.

DOT1L regulates lipid biosynthesis and inflammatory responses in macrophages and promotes atherosclerotic plaque stability.

Macrophages are critical immune cells in inflammatory diseases, and their differentiation and function are tightly regulated by histone modifications. H3K79 methylation is a histone modification associated with active gene expression, and DOT1L is the only histone methyltransferase for H3K79. Here we determine the role of DOT1L in macrophages by applying a selective DOT1L inhibitor in mouse and human macrophages and using myeloid-specific Dot1l-deficient mice. We found that DOT1L directly regulates macrophage function by controlling lipid biosynthesis gene programs including central lipid regulators like sterol regulatory element-binding proteins SREBP1 and SREBP2. DOT1L inhibition also leads to macrophage hyperactivation, which is associated with disrupted SREBP pathways. Invivo, myeloid Dot1l deficiency reduces atherosclerotic plaque stability and increases the activation of inflammatory plaque macrophages. Our data show that DOT1L is a crucial regulator of macrophage inflammatory responses and lipid regulatory pathways and suggest a high relevance of H3K79 methylation in inflammatory disease.

Sleep apnea and carotid atherosclerosis in the Multi-Ethnic Study of Atherosclerosis (MESA): leveraging state-of-the-art vascular imaging.

To further characterize the relationship between obstructive sleep apnea (OSA) and carotid atherosclerosis, we examined the structural and metabolic features of carotid plaque using hybrid 18-F-fluorodeoxyglucose (FDG) Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) in the Multi-Ethnic Study of Atherosclerosis (MESA). We studied 46 individuals from the MESA-PET and MESA-Sleep ancillary studies. OSA was defined as an apnea hypopnea index [AHI] ≥ 15 events per hour (4% desaturation). PET/MRI was used to measure carotid plaque inflammation (using target-to-background-ratios [TBR]) and carotid wall thickness (CWT). Linear regression was used to assess the associations between OSA, CWT and TBR. The mean age was 67.9years (SD 8.53) and the mean BMI was 28.9kg/m2 (SD 4.47). There was a trend toward a higher mean CWT in the OSA (n = 11) vs. non-OSA group (n = 35), 1.51 vs. 1.41 (p = 0.098). TBR did not differ by OSA groups, and there was no significant association between OSA and carotid plaque inflammation (TBR) in adjusted analyses. Although there was a significant interaction between OSA and obesity, there were no statistically significant associations between OSA and vascular inflammation in stratified analysis by obesity. Despite a trend toward a higher carotid wall thickness in OSA vs. non-OSA participants, we did not find an independent association between OSA and carotid plaque inflammation using PET/MRI in MESA. Our findings suggest that simultaneous assessments of structural and metabolic features of atherosclerosis may fill current knowledge gaps pertaining to the influence of OSA on atherosclerosis prevalence and progression.

RNA-m6A modification of HDGF mediated by Mettl3 aggravates the progression of atherosclerosis by regulating macrophages polarization via energy metabolism reprogramming

Macrophage polarization plays a crucial role in atherosclerosis (AS), which is closely associated with energy metabolism. However, the underlying mechanism remains elusive. Hepatoma-derived growth factor (HDGF) has been reported to promote tumor metastasis via energy metabolism reprogramming. In this study, we aimed to investigate the role and underlying mechanism of HDGF in regulating macrophage polarization and AS. Our results suggested the elevated expression of HDGF in aortas from atherosclerotic patients and ApoeKO mice, as well as M1 macrophages. The specific deficiency of HDGF in macrophages resulted in a significant reduction of plaque area, inflammation and M1 macrophages content in ApoeKO mouse model of AS. Consistent with the in vivo data, the specific deficiency of HDGF attenuated the inflammation, glycolysis, and lipids accumulation in M1 macrophages, and rescued the mitochondrial dysfunction. Mechanistically, HDGF plays a crucial role in atherogenesis by regulating the M1 macrophages polarization through energy metabolism reprogramming. The expression level of methyltransferase Mettl3 elevated significantly in M1 macrophages, which contributed to enhancing mRNA stability and protein expression of HDGF via N6-methyladenosine (m6A) RNA methylation. Taken together, our study revealed a novel mechanism underlying the macrophage polarization, which may be a potential therapy for AS.

Sphingolipids in Atherosclerosis: Chimeras in Structure and Function.

Atherosclerosis—a systemic inflammatory disease—is the number one cause of mortality and morbidity worldwide. As such, the prevention of disease progression is of global interest in order to reduce annual deaths at a significant scale. Atherosclerosis is characterized by plaque formation in the arteries, resulting in vascular events such as ischemic stroke or myocardial infarction. A better understanding of the underlying pathophysiological processes at the cellular and molecular level is indispensable to identify novel therapeutic targets that may alleviate disease initiation or progression. Sphingolipids—a lipid class named after the chimeric creature sphinx—are considered to play a critical and, metaphorically, equally chimeric regulatory role in atherogenesis. Previous studies identified six common sphingolipids, namely dihydroceramide (DhCer), ceramide (Cer), sphingosine-1-phosphate (S1P), sphingomyelin (SM), lactosylceramide (LacCer), and glucosylceramide (GluCer) in carotid plaques, and demonstrated their potential as inducers of plaque inflammation. In this review, we point out their specific roles in atherosclerosis by focusing on different cell types, carrier molecules, enzymes, and receptors involved in atherogenesis. Whereas we assume mainly atheroprotective effects for GluCer and LacCer, the sphingolipids DhCer, Cer, SM and S1P mediate chimeric functions. Initial studies demonstrate the successful use of interventions in the sphingolipid pathway to prevent atherosclerosis. However, as atherosclerosis is a multifactorial disease with a variety of underlying cellular processes, it is imperative for future research to emphasize the circumstances in which sphingolipids exert protective or progressive functions and to evaluate their therapeutic benefits in a spatiotemporal manner.

Circulating CD31 reflects endothelial activity and is associated with a lower risk for cardiovascular complications

Abstract Background CD31 is a membrane receptor expressed by leucocytes, platelets and endothelial cells. CD31 regulates endothelial leukocyte transmigration and is key in maintaining endothelial homeostasis. An increased endothelial activation is suggested to contribute to atherosclerotic plaque inflammation but studies focusing on CD31 in atherosclerosis have provided evidence for both pro- and anti-atherosclerotic effects. However, which biological processes that are reflected by circulating soluble CD31 (sCD31) in human atherosclerosis remain unknown. Purpose Here, we aimed to explore 1) which biological processes circulating sCD31 reflects in the human atherosclerotic plaque and circulation 2) if sCD31 levels predicts cardiovascular death in individuals with carotid atherosclerosis and 3) if circulating sCD31 is causally associated to coronary artery disease (CAD) and ischemic stroke, in order to investigate its role as a biomarker of atherosclerotic disease and complications. Methods Cardiovascular associated plasma proteins (n=543) and carotid plaque proteins (n=197) were assessed by a proximity extension assay (Olink, SciLife) in the Carotid Plaque Imaging Project biobank. Plaques were phenotyped by immunohistochemistry. CD31 was located by immunofluorescence. Human carotid artery endothelial cells (HCtAECs) were stimulated with IL-6 and TNF-α to assess sCD31 release. National registries were used to identify cardiovascular death during follow up. All patients gave written informed consent. The study was approved by the local ethical review board and followed the declaration of Helsinki. Causal effects for sCD31 on stroke and CAD were examined by Mendelian randomization (MR). Summary statistics for GWAS of circulating CD31, coronary artery disease and stroke were retrieved from the SCALLOP study, the CARDIoGRAMplusC4D and the MEGASTROKE consortia. Results Plasma sCD31 correlated to plaque sCD31, TNF-α, MMP-2, MMP-9 levels and CD68+ plaque area. Plasma sCD31 also correlated to plasma CSF-1, MCP-1 and IL-8 levels. Clustering and enrichment analyses revealed that plasma sCD31 was associated to angiogenesis, cell migration and inflammatory responses. CD31 was pre-dominantly expressed on the plaque endothelium. TNF-α and IL-6 induced HCtAECs sCD31 release in vitro. Furthermore, low levels of circulating sCD31 predicted cardiovascular death and our MR analyses suggested that low circulating sCD31 levels were causally associated with a higher risk of stroke and CAD. Conclusions The present study shows that circulating sCD31 is released from endothelial cells due to inflammatory stimuli and reflects plaque inflammation. However, our follow-up data and MR analyses suggest that circulating sCD31 is associated with a lower risk for cardiovascular complications. This indicates that circulating sCD31 is not only a marker of an inflammatory response but also a marker of a functional endothelium, able to maintain the endothelial homeostasis. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Swedish Society for Medical Research, The Swedish Research Council, Crafoord foundation, The Swedish Society of Medicine, The Swedish Heart and Lung Foundation, The Knut and Alice Wallenberg foundation, the Medical Faculty at Lund University and Region Skåne.

Founder effect may offer protection from ischemic heart disease in the South-Brazilian Mennonites

Abstract Introduction The Mennonites are an Anabaptist population originated in Europe around 500 years ago. They are a relatively isolated population, established in Brazil in 1930, which suffered three bottleneck effects that reduced their genetic variability and may increase the frequency of diseases. Purpose We aimed to clarify the genetic epidemiology of heart disease in this population. Methods Epidemiological, biometrical and lipidogram data were collected from 2016 to 2020, based on an adapted questionnaire of the Brazilian National Health Research. In total, 485 Mennonites (MEN) and 45 non-Mennonites from three different settlements in Curitiba, Witmarsum, and Colônia Nova (CON) were enrolled in the study. DNA was extracted from blood and 104 exomes from CON, sequenced to >30x coverage. Results The prevalence of hypertension (20.5 vs. 31.8%, p<0.001) and dyslipidemia (41.1% vs. 65.1%, p<0.001) were lower compared to Germans (GER). When compared to Brazilians (BRA), dyslipidemia was higher in Mennonites (23% vs. 41.3%, p<0.001) and hypertension was higher in Brazilians (20.5% vs. 25.7%, p=0.02). The prevalence of overweight among the three populations doesn't have a significant statistical difference (59% MEN, 55.7% BRA, 59.7% GER, p=0.09). Myocardial infarction (MI) prevalence is drastically different between the three (0.6% MEN, 7.1% BR, 4.7% GER, p<0.001). The immigration route had an impact on the cardiovascular disease (CVD) risk when adjusted to, hypertension, sex, first degree relative with CVD, and age. The more extenuating the immigration route of the Mennonites, the higher is the CVD risk (OR 1.57, IC95 1.22–2.03, p=0.001). Forty-five variants of 35 genes were associated with a dominant effect for CVD (p<0.01) independently of sex, age, body mass index, and weekly physical activity. Between those, 38 are known to be associated with mRNA levels on heart/arteries (eQTLs in GTEX), 14 are missense mutations, one causes a frameshift and 18 destroy or create CpG sites with a possible epigenetic effect. The frequency of 14 out 16 alleles differed from non-Finish Europeans and Brazilians, indicating a possible founder effect. Eight are associated with CVD protection (p<0.001). These variants are related to less inflammation of atherosclerotic plaques. Conclusion The South-Brazilian Mennonite population seems to have some kind of protection for ischemic heart disease, which may rely on founder effects that raised the frequencies of protective alleles. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): CAPES for PROAP finance Code 001, and scholarships for WAVJ and LCO. ABWB receives a research productivity scholarship from CNPq (protocol 314288/2018-0).