Mouse models of atherosclerosis in translational research

Berberine Inhibits Ferroptosis and Stabilizes Atherosclerotic Plaque through NRF2/SLC7A11/GPX4 Pathway

OBJECTIVE

To investigate potential mechanisms of anti-atherosclerosis by berberine (BBR) using ApoE-/- mice.

METHODS

Eight 8-week-old C57BL/6J mice were used as a blank control group (normal), and 56 8-week-old AopE-/- mice were fed a high-fat diet for 12 weeks, according to a completely random method, and were divided into the model group, BBR low-dose group (50 mg/kg, BBRL), BBR medium-dose group (100 mg/kg, BBRM), BBR high-dose group (150 mg/kg, BBRH), BBR+nuclear factor erythroid 2-related factor 2 (NRF2) inhibitor group (100 mg/kg BBR+30 mg/kg ML385, BBRM+ML385), NRF2 inhibitor group (30 mg/kg, ML385), and positive control group (2.5 mg/kg, atorvastatin), 8 in each group. After 4 weeks of intragastric administration, samples were collected and serum, aorta, heart and liver tissues were isolated. Biochemical kits were used to detect serum lipid content and the expression levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in all experimental groups. The pathological changes of atherosclerosis (AS) were observed by aorta gross Oil Red O, aortic sinus hematoxylin-eosin (HE) and Masson staining. Liver lipopathy was observed in mice by HE staining. The morphology of mitochondria in aorta cells was observed under transmission electron microscope. Flow cytometry was used to detect reactive oxygen species (ROS) expression in aorta of mice in each group. The content of ferrous ion Fe2+ in serum of mice was detected by biochemical kit. The mRNA and protein relative expression levels of NRF2, glutathione peroxidase 4 (GPX4) and recombinant solute carrier family 7 member 11 (SLC7A11) were detected by quantitative real time polymerase chain reaction (RT-qPCR) and Western blot, respectively.

RESULTS

BBRM and BBRH groups delayed the progression of AS and reduced the plaque area (P<0.01). The characteristic morphological changes of ferroptosis were rarely observed in BBR-treated AS mice, and the content of Fe2+ in BBR group was significantly lower than that in the model group (P<0.01). BBR decreased ROS and MDA levels in mouse aorta, increased SOD activity (P<0.01), significantly up-regulated NRF2/SLC7A11/GPX4 protein and mRNA expression levels (P<0.01), and inhibited lipid peroxidation. Compared with the model group, the body weight, blood lipid level and aortic plaque area of ML385 group increased (P<0.01); the morphology of mitochondria showed significant ferroptosis characteristics; the serum Fe2+, MDA and ROS levels increased (P<0.05 or P<0.01), and the activity of SOD decreased (P<0.01). Compared with BBRM group, the iron inhibition effect of BBRM+ML385 group was significantly weakened, and the plaque area significantly increased (P<0.01).

CONCLUSION

Through NRF2/SLC7A11/GPX4 pathway, BBR can resist oxidative stress, inhibit ferroptosis, reduce plaque area, stabilize plaque, and exert anti-AS effects.

The biogenesis and transport of triglyceride-rich lipoproteins

Triglyceride-rich lipoproteins (TRLs) play essential roles in human health and disease by transporting bulk lipids into the circulation. This review summarizes the fundamental mechanisms and diverse factors governing lipoprotein production, secretion, and regulation. Emphasizing the broader implications for human health, we outline the intricate landscape of lipoprotein research and highlight the potential coordination between the biogenesis and transport of TRLs in physiology, particularly the unexpected coupling of metabolic enzymes and transport machineries. Challenges and opportunities in lipoprotein biology with respect to inherited diseases and viral infections are also discussed. Further characterization of the biogenesis and transport of TRLs will advance both basic research in lipid biology and translational medicine for metabolic diseases.

Targeting the tyrosine kinase Src in endothelium attenuates inflammation and atherogenesis induced by disturbed flow

BACKGROUND AND PURPOSE

Previous studies have shown that Src can regulate inflammation and tumour progression. However, the mechanisms by which Src regulates the inflammatory response of vascular endothelium and atherogenesis are currently poorly understood. This study aimed to investigate the role of Src in endothelial inflammation and atherogenesis, as well as the underlying mechanisms.

EXPERIMENTAL APPROACH

Real-time quantitative PCR was used to measure the mRNA levels of inflammatory genes. The phosphorylation and localization of proteins were examined using western blotting and immunofluorescence, respectively. The level of p-Src Y416 in mouse endothelium was directly determined using en face staining. Endothelial-specific knockdown of Src was achieved by tail vein injection of AAV-sgSrc in ApoE-/-; Cas9LSL/LSL; Cdh5-cre mice. Atherosclerosis was induced by partial ligation of the carotid artery.

KEY RESULTS

Oscillatory shear stress (OSS) promotes the phosphorylation of Src at Y416 in endothelial cells, and Piezo1 is required for this regulatory process. Overexpression of constitutively active Src promotes endothelial inflammation, as well as phosphorylation of Stat3 (at Y705) and its nuclear translocation. Endothelial inflammation induced by OSS was abolished by the Src inhibitor dasatinib or si-Src. Dasatinib, when administered orally, reduced endothelial inflammation and plaque formation in ApoE-/- mice induced by partial carotid artery ligation. Additionally, plaque formation was decreased in the ligated left carotid artery of mice with endothelial-specific Src knockdown.

CONCLUSION AND IMPLICATIONS

Disturbed flow promotes endothelial inflammation and atherogenesis through the Piezo1-Src-Stat3 pathway. Therefore, inhibiting Src in endothelial cells could be a promising therapeutic strategy to treat atherogenesis.

Role of long noncoding RNAs in diabetes-associated peripheral arterial disease

Diabetes mellitus (DM) is a metabolic disease that heightens the risks of many vascular complications, including peripheral arterial disease (PAD). Various types of cells, including but not limited to endothelial cells (ECs), vascular smooth muscle cells (VSMCs), and macrophages (MΦs), play crucial roles in the pathogenesis of DM-PAD. Long non-coding RNAs (lncRNAs) are epigenetic regulators that play important roles in cellular function, and their dysregulation in DM can contribute to PAD. This review focuses on the developing field of lncRNAs and their emerging roles in linking DM and PAD. We review the studies investigating the role of lncRNAs in crucial cellular processes contributing to DM-PAD, including those in ECs, VSMCs, and MΦ. By examining the intricate molecular landscape governed by lncRNAs in these relevant cell types, we hope to shed light on the roles of lncRNAs in EC dysfunction, inflammatory responses, and vascular remodeling contributing to DM-PAD. Additionally, we provide an overview of the research approach and methodologies, from identifying disease-relevant lncRNAs to characterizing their molecular and cellular functions in the context of DM-PAD. We also discuss the potential of leveraging lncRNAs in the diagnosis and therapeutics for DM-PAD. Collectively, this review provides a summary of lncRNA-regulated cell functions contributing to DM-PAD and highlights the translational potential of leveraging lncRNA biology to tackle this increasingly prevalent and complex disease.

Urolithin A promotes atherosclerotic plaque stability by limiting inflammation and hypercholesteremia in Apolipoprotein E-deficient mice

Urolithin A (UroA), a dietary phytochemical, is produced by gut bacteria from fruits rich in natural polyphenols ellagitannins (ETs). The efficiency of ETs metabolism to UroA in humans depends on gut microbiota. UroA has shown a variety of pharmacological activities. In this study we investigated the effects of UroA on atherosclerotic lesion development and stability. Apolipoprotein E-deficient (ApoE-/-) mice were fed a high-fat and high-cholesterol diet for 3 months to establish atherosclerosis model. Meanwhile the mice were administered UroA (50 mg·kg-1·d-1, i.g.). We showed that UroA administration significantly decreased diet-induced atherosclerotic lesions in brachiocephalic arteries, macrophage content in plaques, expression of endothelial adhesion molecules, intraplaque hemorrhage and size of necrotic core, while increased the expression of smooth muscle actin and the thickness of fibrous cap, implying features of plaque stabilization. The underlying mechanisms were elucidated using TNF-α-stimulated human endothelial cells. Pretreatment with UroA (10, 25, 50 μM) dose-dependently inhibited TNF-α-induced endothelial cell activation and monocyte adhesion. However, the anti-inflammatory effects of UroA in TNF-α-stimulated human umbilical vein endothelial cells (HUVECs) were independent of NF-κB p65 pathway. We conducted RNA-sequencing profiling analysis to identify the differential expression of genes (DEGs) associated with vascular function, inflammatory responses, cell adhesion and thrombosis in UroA-pretreated HUVECs. Human disease enrichment analysis revealed that the DEGs were significantly correlated with cardiovascular diseases. We demonstrated that UroA pretreatment mitigated endothelial inflammation by promoting NO production and decreasing YAP/TAZ protein expression and TEAD transcriptional activity in TNF-α-stimulated HUVECs. On the other hand, we found that UroA administration modulated the transcription and cleavage of lipogenic transcription factors SREBP1/2 in the liver to ameliorate cholesterol metabolism in ApoE-/- mice. This study provides an experimental basis for new dietary therapeutic option to prevent atherosclerosis.

Notoginsenoside R1 decreases intraplaque neovascularization by governing pericyte-endothelial cell communication via Ang1/Tie2 axis in atherosclerosis

Atherosclerosis represents the major cause of mortality worldwide and triggers higher risk of acute cardiovascular events. Pericytes-endothelial cells (ECs) communication is orchestrated by ligand-receptor interaction generating a microenvironment which results in intraplaque neovascularization, that is closely associated with atherosclerotic plaque instability. Notoginsenoside R1 (R1) exhibits anti-atherosclerotic bioactivity, but its effect on angiogenesis in atherosclerotic plaque remains elusive. The aim of our study is to explore the therapeutic effect of R1 on vulnerable plaque and investigate its potential mechanism against intraplaque neovascularization. The impacts of R1 on plaque stability and intraplaque neovascularization were assessed in ApoE-/- mice induced by high-fat diet. Pericytes-ECs direct or non-direct contact co-cultured with VEGF-A stimulation were used as the in vitro angiogenesis models. Overexpressing Ang1 in pericytes was performed to investigate the underlying mechanism. In vivo experiments, R1 treatment reversed atherosclerotic plaque vulnerability and decreased the presence of neovessels in ApoE-/- mice. Additionally, R1 reduced the expression of Ang1 in pericytes. In vitro experiments demonstrated that R1 suppressed pro-angiogenic behavior of ECs induced by pericytes cultured with VEGF-A. Mechanistic studies revealed that the anti-angiogenic effect of R1 was dependent on the inhibition of Ang1 and Tie2 expression, as the effects were partially reversed after Ang1 overexpressing in pericytes. Our study demonstrated that R1 treatment inhibited intraplaque neovascularization by governing pericyte-EC association via suppressing Ang1-Tie2/PI3K-AKT paracrine signaling pathway. R1 represents a novel therapeutic strategy for atherosclerotic vulnerable plaques in clinical application.

AMPK-mediated regulation of endogenous cholesterol synthesis does not affect atherosclerosis in a murine Pcsk9-AAV model

BACKGROUND AND AIMS

Dysregulated cholesterol metabolism is a hallmark of atherosclerotic cardiovascular diseases, yet our understanding of how endogenous cholesterol synthesis affects atherosclerosis is not clear. The energy sensor AMP-activated protein kinase (AMPK) phosphorylates and inhibits the rate-limiting enzyme in the mevalonate pathway HMG-CoA reductase (HMGCR). Recent work demonstrated that when AMPK-HMGCR signaling was compromised in an Apoe-/- model of hypercholesterolemia, atherosclerosis was exacerbated due to elevated hematopoietic stem and progenitor cell mobilization and myelopoiesis. We sought to validate the significance of the AMPK-HMGCR signaling axis in atherosclerosis using a non-germline hypercholesterolemia model with functional ApoE.

METHODS

Male and female HMGCR S871A knock-in (KI) mice and wild-type (WT) littermate controls were made atherosclerotic by intravenous injection of a gain-of-function Pcsk9D374Y-adeno-associated virus followed by high-fat and high-cholesterol atherogenic western diet feeding for 16 weeks.

RESULTS

AMPK activation suppressed endogenous cholesterol synthesis in primary bone marrow-derived macrophages from WT but not HMGCR KI mice, without changing other parameters of cholesterol regulation. Atherosclerotic plaque area was unchanged between WT and HMGCR KI mice, independent of sex. Correspondingly, there were no phenotypic differences observed in hematopoietic progenitors or differentiated immune cells in the bone marrow, blood, or spleen, and no significant changes in systemic markers of inflammation. When lethally irradiated female mice were transplanted with KI bone marrow, there was similar plaque content relative to WT.

CONCLUSIONS

Given previous work, our study demonstrates the importance of preclinical atherosclerosis model comparison and brings into question the importance of AMPK-mediated control of cholesterol synthesis in atherosclerosis.

A novel mouse model of familial combined hyperlipidemia and atherosclerosis

Within the context of residual cardiovascular risk in post-statin era, emerging evidence from epidemiologic and human genetic studies have demonstrated that triglyceride (TG)-rich lipoproteins and their remnants are causally related to cardiovascular risk. While, carriers of loss-of-function mutations of ApoC3 have low TG levels and are protected from cardiovascular disease (CVD). Of translational significance, siRNAs/antisense oligonucleotide (ASO) targeting ApoC3 is beneficial for patients with atherosclerotic CVD. Therefore, animal models of atherosclerosis with both hypercholesterolemia and hypertriglyceridemia are important for the discovery of novel therapeutic strategies targeting TG-lowering on top of traditional cholesterol-lowering. In this study, we constructed a novel mouse model of familial combined hyperlipidemia through inserting a human ApoC3 transgene (hApoC3-Tg) into C57BL/6 J mice and injecting a gain-of-function variant of adeno-associated virus-proprotein convertase subtilisin/kexin type 9 (AAV-PCSK9)-D377Y concurrently with high cholesterol diet (HCD) feeding for 16 weeks. In the last 10 weeks, hApoC3-Tg mice were orally treated with a combination of atorvastatin (10 mg·kg-1·d-1) and fenofibrate (100 mg·kg-1·d-1). HCD-treated hApoC3-Tg mice demonstrated elevated levels of serum TG, total cholesterol (TC) and low density lipoprotein-cholesterol (LDL-C). Oral administration of atorvastatin and fenofibrate significantly decreased the plaque sizes of en face aorta, aortic sinus and innominate artery accompanied by improved lipid profile and distribution. In summary, this novel mouse model is of considerable clinical relevance for evaluation of anti-atherosclerotic drugs by targeting both hypercholesterolemia and hypertriglyceridemia.

Advances in the treatment of atherosclerosis with ligand-modified nanocarriers

Atherosclerosis, a chronic disease associated with metabolism, poses a significant risk to human well-being. Currently, existing treatments for atherosclerosis lack sufficient efficiency, while the utilization of surface-modified nanoparticles holds the potential to deliver highly effective therapeutic outcomes. These nanoparticles can target and bind to specific receptors that are abnormally over-expressed in atherosclerotic conditions. This paper reviews recent research (2018-present) advances in various ligand-modified nanoparticle systems targeting atherosclerosis by specifically targeting signature molecules in the hope of precise treatment at the molecular level and concludes with a discussion of the challenges and prospects in this field. The intention of this review is to inspire novel concepts for the design and advancement of targeted nanomedicines tailored specifically for the treatment of atherosclerosis.

The natural polyphenol fisetin in atherosclerosis prevention: a mechanistic review

The incidence and mortality rate of atherosclerotic cardiovascular disease (ASCVD) is increasing yearly worldwide. Recently, a growing body of evidence has unveiled the anti-atherosclerotic properties of fisetin, a natural polyphenol compound. In this article, we reviewed the pharmacologic actions of fisetin on experimental atherosclerosis and its protective effects on disease-relevant cell types such as endothelial cells, macrophages, vascular smooth muscle cells, and platelets. Based on its profound cardiovascular actions, fisetin holds potential for clinical translation and could be developed as a potential therapeutic option for atherosclerosis and its related complications. Large-scale randomized clinical trials are warranted to ascertain the safety and efficacy of fisetin in patients with or high risk for ASCVD.

Dual-modality probe nanodrug delivery systems with ROS-sensitivity for atherosclerosis diagnosis and therapy

Most acute cardiovascular and cerebrovascular diseases are caused by atherosclerotic plaque rupture leading to blocked arteries. Targeted nanodelivery systems deliver imaging agents or drugs to target sites for diagnostic imaging or the treatment of various diseases, providing new insights for the detection and treatment of atherosclerosis. Based on the pathological characteristics of atherosclerosis, a hydrogen peroxide-sensitive bimodal probe PPIS@FC with integrated diagnosis and treatment function was designed. Bimodal probes Fe3O4@SiO2-CDs (FC) were prepared by coupling superparamagnetic iron oxide and carbon quantum dots synthesized with citric acid, and self-assembled with hydrogen peroxide stimulus-responsive amphiphilic block polymer PGMA-PEG modified with simvastatin (Sim) and target molecule ISO-1 to obtain drug-loaded micelles PGMA-PEG-ISO-1-Sim@FC (PPIS@FC). PPIS@FC could release Sim and FC in an H2O2-triggered manner, achieving the goal of releasing drugs using the special microenvironment at the plaque. At the same time, in vivo magnetic resonance and fluorescence imaging results proved that PPIS@FC possessed targeting ability, magnetic resonance imaging and fluorescence imaging effects. The results of the FeCl3 and ApoE-/- model showed that PPIS@FC had an excellent therapeutic effect and in vivo safety. Therefore, dual-modality imaging drug delivery systems with ROS response will become a promising strategy for the diagnosis and treatment of atherosclerosis.

Gamma protocadherins in vascular endothelial cells inhibit Klf2/4 to promote atherosclerosis

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of mortality worldwide1. Laminar shear stress (LSS) from blood flow in straight regions of arteries protects against ASCVD by upregulating the Klf2/4 anti-inflammatory program in endothelial cells (ECs)2-8. Conversely, disturbed shear stress (DSS) at curves or branches predisposes these regions to plaque formation9,10. We previously reported a whole genome CRISPR knockout screen11 that identified novel inducers of Klf2/4. Here we report suppressors of Klf2/4 and characterize one candidate, protocadherin gamma A9 (Pcdhga9), a member of the clustered protocadherin gene family12. Pcdhg deletion increases Klf2/4 levels in vitro and in vivo and suppresses inflammatory activation of ECs. Pcdhg suppresses Klf2/4 by inhibiting the Notch pathway via physical interaction of cleaved Notch1 intracellular domain (NICD Val1744) with nuclear Pcdhg C-terminal constant domain (CCD). Pcdhg inhibition by EC knockout (KO) or blocking antibody protects from atherosclerosis. Pcdhg is elevated in the arteries of human atherosclerosis. This study identifies a novel fundamental mechanism of EC resilience and therapeutic target for treating inflammatory vascular disease.

Macrophage KLF15 prevents foam cell formation and atherosclerosis via transcriptional suppression of OLR-1

BACKGROUND

Macrophage-derived foam cells are a hallmark of atherosclerosis. Scavenger receptors, including lectin-like oxidized low-density lipoprotein (LDL) receptor-1 (OLR-1), are the principal receptors responsible for the uptake and modification of LDL, facilitating macrophage lipid load and the uptake of oxidized LDL by arterial wall cells. Krüppel-like factor 15 (KLF15) is a transcription factor that regulates the expression of genes by binding to the promoter during transcription. Therefore, this study aimed to investigate the precise role of macrophage KLF15 in atherogenesis.

METHODS

We used two murine models of atherosclerosis: mice injected with an adeno-associated virus (AAV) encoding the Asp374-to-Tyr mutant version of human PCSK9, followed by 12 weeks on a high-fat diet (HFD), and ApoE-/-- mice on a HFD. We subsequently injected mice with AAV-KLF15 and AAV-LacZ to assess the role of KLF15 in the development of atherosclerosis in vivo. Oil Red O, H&E, and Masson's trichome staining were used to evaluate atherosclerotic lesions. Western blots and RT-qPCR were used to assess protein and mRNA levels, respectively.

RESULTS

We determined that KLF15 expression was downregulated during atherosclerosis formation, and KLF15 overexpression prevented atherosclerosis progression. KLF15 expression levels did not affect body weight or serum lipid levels in mice. However, KLF15 overexpression in macrophages prevented foam cell formation by reducing OLR-1-meditated lipid uptake. KLF15 directly targeted and transcriptionally downregulated OLR-1 levels. Restoration of OLR-1 reversed the beneficial effects of KLF15 in atherosclerosis.

CONCLUSION

Macrophage KLF15 transcriptionally downregulated OLR-1 expression to reduce lipid uptake, thereby preventing foam cell formation and atherosclerosis. Thus, our results suggest that KLF15 is a potential therapeutic target for atherosclerosis.

Diethylaminoethyl-dextran and monocyte cell membrane coated 1,8-cineole delivery system for intracellular delivery and synergistic treatment of atherosclerosis

We have developed a biomimetic delivery system termed the Monocyte Cell Membrane-Coated 1,8-Cineole Biomimetic Delivery System (MM-CIN-BDS or BDS), which integrates diethylaminoethyl-dextran (DEAE) and monocyte cell membrane (MM). This innovative approach enhances the cellular uptake efficiency of 1,8-cineole (CIN) and facilitates targeted therapy for atherosclerosis. Our findings demonstrate the successful modification of the drug carrier with DEAE and MM, as validated by measurements of particle size, zeta potential, microscopic morphology, and western blotting analyses. Notably, cellular uptake experiments unveil a significant enhancement in cellular uptake efficiency due to DEAE modification. However, the introduction of monocyte cell membranes diminishes this effect in normal human umbilical vein endothelial cells (HUVECs), although this efficiency is notably restored in HUVECs activated with lipopolysaccharide (LPS). Through in vivo imaging investigations, we observe that the MM coating augments distribution in the spleen, brain, and atherosclerotic plaques, while concurrently diminishing distribution in the heart and kidneys. Animal studies corroborate these findings, illustrating that MM-CIN-BDS treatment curtails lipid parameters, dampens the expression of inflammatory factors and proteins, mitigates vascular tissue damage, and ultimately reduces the extent of atherosclerotic lesion areas. To encapsulate, DEAE emerges as an especially adept agent for modifying drug carriers with suboptimal cellular uptake efficiency in the realm of cardiovascular diseases. The potential therapeutic promise of MM-CIN-BDS for atherosclerosis treatment is evident from our research.

Iron and atherosclerosis: Lessons learned from rabbits relevant to human disease

The role of iron in promoting atherosclerosis, and hence the cardiovascular, neurodegenerative and other diseases that result from atherosclerosis, has been fiercely controversial. Many studies have been carried out on various rodent models of atherosclerosis, especially on apoE-knockout (apoE-/-) mice, which develop atherosclerosis more readily than normal mice. These apoE-/- mouse studies generally support a role for iron in atherosclerosis development, although there are conflicting results. The purpose of the current article is to describe studies on another animal model that is not genetically manipulated; New Zealand White (NZW) rabbits fed a high-cholesterol diet. This may be a better model than the apoE-/- mice for human atherosclerosis, although it has been given much less attention. Studies on NZW rabbits support the view that iron promotes atherosclerosis, although some uncertainties remain, which need to be resolved by further experimentation.

Animal Models of Human Disease

The use of animal models of human disease is critical for furthering our understanding of disease mechanisms, for the discovery of novel targets for treatment, and for translational research. This Special Topic entitled "Animal Models of Human Disease" aimed to collect state-of-the-art primary research studies and review articles from international experts and leading groups using animal models to study human diseases. Submissions were welcomed on a wide range of animal models and pathologies, including infectious disease, acute injury, regeneration, cancer, autoimmunity, degenerative and chronic disease. Seven participating MDPI journals supported the Special Topic, namely: Biomedicines, Cells, Current Issues in Molecular Biology, Diagnostics, Genes, the International Journal of Molecular Sciences, and the International Journal of Translational Medicine. In total, 46 papers were published in this Special Topic, with 37 full length original research papers, 2 research communications and 7 reviews. These contributions cover a wide range of clinically relevant, translatable, and comparative animal models, as well as furthering understanding of fundamental sciences, covering topics on physiological processes, on degenerative, inflammatory, infectious, autoimmune, neurological, metabolic, heamatological, hormonal and mitochondrial disorders, developmental processes and diseases, cardiology, cancer, trauma, stress, and ageing.

Vascular Ultrasound for In Vivo Assessment of Arterial Pathologies in a Murine Model of Atherosclerosis and Aortic Aneurysm

Vascular diseases like atherosclerosis and abdominal aortic aneurysm (AAA) are common pathologies in the western world, promoting various potentially fatal conditions. Here, we evaluate high-resolution (HR) ultrasound in mouse models of atherosclerosis and AAA as a useful tool for noninvasive monitoring of early vascular changes in vivo. We used Apolipoprotein E-deficient (ApoE-/-) mice as an atherosclerosis model and induced AAA development by the implementation of Angiotensin II-releasing osmotic minipumps. HR ultrasound of the carotid artery or the abdominal aorta was performed to monitor vascular remodeling in vivo. Images were analyzed by speckle tracking algorithms and correlated to histological analyses and subsequent automated collagen quantification. Consistent changes were observed via ultrasound in both models: Global radial strain (GRS) was notably reduced in the AAA model (23.8 ± 2.8% vs. 12.5 ± 2.5%, p = 0.01) and in the atherosclerotic mice (20.6 ± 1.3% vs. 15.8 ± 0.9%, p = 0.02). In mice with AAA, vessel distensibility was significantly reduced, whereas intima-media thickness was increased in atherosclerotic mice. The area and collagen content of the tunica media were increased in diseased arteries of both models as measured by automated image analysis of Picrosirius Red-stained aortic sections. Correlation analysis revealed a strong correlation of multiple parameters, predicting early vascular damage in HR ultrasound and histological examinations. In conclusion, our findings underscore the potential of HR ultrasound in effectively tracing early alterations in arterial wall properties in murine models of atherosclerosis and AAA.

Cardiovascular manifestations of monogenic periodic fever syndromes

Periodic fever syndromes (PFS) are a group of autoinflammatory diseases characterized by repeated febrile episodes and systemic inflammation. The most common monogenic periodic fever syndromes are familial Mediterranean fever, mevalonate kinase deficiency/hyper immunoglobulin D syndrome, cryopyrin-associated periodic syndrome, and tumor necrosis factor receptor-associated periodic syndrome. Although fever is the predominant feature of PFS, other systems, including the cardiovascular system, may be involved in the disease process. This review focuses on cardiovascular risks and issues in monogenic PFS. Cardiovascular involvement may occur as a disease manifestation, association, or result of complications or a drug's adverse effects in monogenic PFS. Pericarditis seems to be a feature of PFS. Patients with recurrent pericarditis or pericarditis resistant to conventional treatment should be evaluated for PFS. Amyloidosis is the most severe complication of PFS, increasing the risk of cardiac morbidity. Furthermore, ongoing inflammation may result in early atherosclerosis. Therefore, assessing cardiovascular risks in PFS patients should be considered a part of routine care. Key points • Pericarditis is the most common cardiac involvement of monogenic periodic fever syndromes (PFS), while some forms may present with myocarditis. • Amyloidosis, the most significant complication of PFS, may lead to deterioration in cardiac functions. • Ongoing inflammation in PFS may result in endothelial dysfunction and atherosclerosis. • Effective control of inflammation and reducing concomitant risk factors such as obesity, diabetes mellitus, and hypertension could improve cardiovascular outcomes in PFS patients.

The quality and quantity media-cultured mononuclear cell transplantation is safe and effective in ischemic hindlimb mouse model

Objective

This study was conducted to investigate in vitro proangiogenic and anti-inflammatory phenotypes and functions and the in vivo efficacy and safety of quality and quantity (QQ) media-cultured mononuclear cells (MNCs) compared with standard cultured MNCs from the peripheral blood of patients with chronic limb-threatening ischemia (CLTI) with atherosclerotic risk factors.

Methods

Peripheral blood MNCs (PBMNCs) from patients with CLTI were cultured in QQ culture media or standard culture media. Phenotypic analysis of progenitor cells (CD34+CD133+), M2 macrophages (CD206+), and inactivated T regulatory cells (CD4+CD25+CD127+), colony-forming assay, and tube formation assay of QQ media-cultured MNCs (QQMNCs) and PBMNCs, were conducted. Intramuscular transplantation of QQMNCs or PBMNCs was performed in the ischemic hindlimb model. The clinical appearance of ischemic limbs was observed, and blood flow in ischemic limbs was measured using a laser Doppler perfusion imager. Outcomes were compared between the QQMNC and PBMNC groups.

Results

Twenty patients with CLTI were included. The mean percentages of CD34+ cells, CD133+ cells, CD34+CD133+ progenitor cells, CD206+ cells, colony-forming cells, and tube formation were significantly higher in the QQMNCs. The mean percentage of CD4+CD25+CD127+ cells was significantly lower in QQMNC. The colony-forming unit count and Dil-acetylated low-density lipoprotein uptake were significantly greater in QQMNCs. The clinical appearance of post-QQMNC-injected limbs was less severe than the appearance of post-PBMNC-injected limbs. Limb perfusion was significantly better in the QQMNCs.

Conclusions

Proangiogenic and anti-inflammatory phenotypes of MNCs cultured in QQ culture media were reproducible. Intramuscular QQMNC transplantation was safe and resulted in better reperfusion of ischemic hindlimbs compared with PBMNCs.

B- and T-lymphocyte attenuator could be a new player in accelerated atherosclerosis associated with chronic kidney disease

BACKGROUND

In chronic kidney disease (CKD), cardiovascular morbi-mortality is higher than in general population. Atherosclerotic cardiovascular disease is accelerated in CKD, but specific CKD-related risk factors for atherosclerosis are unknown.

METHODS

CKD patients from the NEFRONA study were used. We performed mRNA array from blood of patients free from atheroma plaque at baseline, with (n=10) and without (n=10) de novo atherosclerotic plaque development 2 years later. Selected mRNA candidates were validated in a bigger sample (n=148). Validated candidates were investigated in vivo in an experimental model of CKD-accelerated atherosclerosis, and in vitro in murine macrophages.

RESULTS

mRNA array analysis showed 92 up-regulated and 67 down-regulated mRNAs in samples from CKD patients with de novo plaque development. The functional analysis pointed to a paramount role of the immune response. The validation in a bigger sample confirmed that B- and T-lymphocyte co-inhibitory molecule (BTLA) down-regulation was associated with de novo plaque presence after 2 years. However, BTLA down-regulation was not found to be associated with atherosclerotic progression in patients with plaque already present at baseline. In a model of CKD-accelerated atherosclerosis, mRNA and protein expression levels of BTLA were significantly decreased in blood samples and atheroma plaques. Plaques from animals with CKD were bigger, had more infiltration of inflammatory cells, higher expression of IL6 and IL17 and less presence of collagen than plaques from control animals. Incubation of macrophages with rat uremic serum decreased BTLA expression.

CONCLUSIONS

BTLA could be a potential biomarker or therapeutic target for atherosclerosis incidence in CKD patients.

Apolipoprotein E and viral infection: Risks and Mechanisms

Apolipoprotein E (ApoE) is a multifunctional protein critical for lipid metabolism and cholesterol homeostasis. In addition to being a well known genetic determinant of both neurodegenerative and cardiovascular diseases, ApoE is frequently involved in various viral infection-related diseases. Human ApoE protein is functionally polymorphic with three isoforms, namely, ApoE2, ApoE3, and ApoE4, with markedly altered protein structures and functions. ApoE4 is associated with increased susceptibility to infection with herpes simplex virus type-1 and HIV. Conversely, ApoE4 protects against hepatitis C virus and hepatitis B virus infection. With the outbreak of coronavirus disease 2019, ApoE4 has been shown to determine the incidence and progression of severe acute respiratory syndrome coronavirus 2 infection. These findings clearly indicate the critical role of ApoE in viral infection. Furthermore, ApoE polymorphism has various or even opposite effects in these infection processes, which are partly related to the structural features that distinguish the different ApoE statuses. In the current review, we summarize the emerging relationship between ApoE and viral infection, discuss the potential mechanisms, and identify future directions that may help to advance our understanding of the link between ApoE and viral infection.

The role of peroxisome proliferator-activated receptor γ in lipid metabolism and inflammation in atherosclerosis

Cardiovascular disease events are the result of functional and structural abnormalities in the arteries and heart. Atherosclerosis is the main cause and pathological basis of cardiovascular diseases. Atherosclerosis is a multifactorial disease associated with dyslipidemia, inflammation, and oxidative stress, among which dyslipidemia and chronic inflammation occur in all processes. Under the influence of lipoproteins, the arterial intima causes inflammation, necrosis, fibrosis, and calcification, leading to plaque formation in specific parts of the artery, which further develops into plaque rupture and secondary thrombosis. Foam cell formation from macrophages is an early event in the development of atherosclerosis. Lipid uptake causes a vascular inflammatory response, and persistent inflammatory infiltration in the lesion area further promotes the development of the disease. Inhibition of macrophage differentiation into foam cell and reduction of the level of proinflammatory factors in macrophages can effectively alleviate the occurrence and development of atherosclerosis. Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated nuclear receptor that plays an important antiatherosclerotic role by regulating triglyceride metabolism, lipid uptake, cholesterol efflux, macrophage polarity, and inhibiting inflammatory signaling pathways. In addition, PPARγ shifts its binding to ligands and co-activators or co-repressors of transcription of target genes through posttranslational modification, thereby affecting the regulation of its downstream target genes. Many ligand agonists have also been developed targeting PPARγ. In this review, we summarized the role of PPARγ in lipid metabolism and inflammation in development of atherosclerosis, the posttranslational regulatory mechanism of PPARγ, and further discusses the value of PPARγ as an antiatherosclerosis target.

Sirtuin 2 deficiency aggravates ageing-induced vascular remodelling in humans and mice

AIMS

The mechanisms underlying ageing-induced vascular remodelling remain unclear. This study investigates the role and underlying mechanisms of the cytoplasmic deacetylase sirtuin 2 (SIRT2) in ageing-induced vascular remodelling.

METHODS AND RESULTS

Transcriptome and quantitative real-time PCR data were used to analyse sirtuin expression. Young and old wild-type and Sirt2 knockout mice were used to explore vascular function and pathological remodelling. RNA-seq, histochemical staining, and biochemical assays were used to evaluate the effects of Sirt2 knockout on the vascular transcriptome and pathological remodelling and explore the underlying biochemical mechanisms. Among the sirtuins, SIRT2 had the highest levels in human and mouse aortas. Sirtuin 2 activity was reduced in aged aortas, and loss of SIRT2 accelerated vascular ageing. In old mice, SIRT2 deficiency aggravated ageing-induced arterial stiffness and constriction-relaxation dysfunction, accompanied by aortic remodelling (thickened vascular medial layers, breakage of elastin fibres, collagen deposition, and inflammation). Transcriptome and biochemical analyses revealed that the ageing-controlling protein p66Shc and metabolism of mitochondrial reactive oxygen species (mROS) contributed to SIRT2 function in vascular ageing. Sirtuin 2 repressed p66Shc activation and mROS production by deacetylating p66Shc at lysine 81. Elimination of reactive oxygen species by MnTBAP repressed the SIRT2 deficiency-mediated aggravation of vascular remodelling and dysfunction in angiotensin II-challenged and aged mice. The SIRT2 coexpression module in aortas was reduced with ageing across species and was a significant predictor of age-related aortic diseases in humans.

CONCLUSION

The deacetylase SIRT2 is a response to ageing that delays vascular ageing, and the cytoplasm-mitochondria axis (SIRT2-p66Shc-mROS) is important for vascular ageing. Therefore, SIRT2 may serve as a potential therapeutic target for vascular rejuvenation.

Time-restricted feeding attenuates hypercholesterolaemia and atherosclerosis development during circadian disturbance in APOE∗3-Leiden.CETP mice

BACKGROUND

Circadian disturbance (CD) is the consequence of a mismatch between endogenous circadian rhythms, behaviour, and/or environmental cycles, and frequently occurs during shift work. Shift work has been associated with elevated risk for atherosclerotic cardiovascular disease (asCVD) in humans, but evidence for the effectiveness of prevention strategies is lacking.

METHODS

Here, we applied time-restricted feeding (TRF) as a strategy to counteract atherosclerosis development during CD in female APOE∗3-Leiden.CETP mice, a well-established model for humanized lipoprotein metabolism. Control groups were subjected to a fixed 12:12 h light-dark cycle, while CD groups were subjected to 6-h phase advancement every 3 days. Groups had either ad libitum (AL) access to food or were subjected to TRF with restricted food access to the dark phase.

FINDINGS

TRF did not prevent the increase in the relative abundance of circulating inflammatory monocytes and elevation of (postprandial) plasma triglycerides during CD. Nonetheless, TRF reduced atherosclerotic lesion size and prevented an elevation in macrophage content of atherosclerotic lesions during CD, while it increased the relative abundance of anti-inflammatory monocytes, prevented activation of T cells, and lowered plasma total cholesterol levels and markers of hepatic cholesterol synthesis. These effects were independent of total food intake.

INTERPRETATION

We propose that time restricted eating could be a promising strategy for the primary prevention of asCVD risk in shift workers, which warrants future study in humans.

FUNDING

This work was funded by the Novo Nordisk Foundation, the Netherlands Ministry of Social Affairs and Employment, Amsterdam Cardiovascular Sciences, and the Dutch Heart Foundation.

Iron metabolism and atherosclerosis

Despite several decades of study, whether iron is involved in the development of atherosclerosis remains a controversial and unresolved issue. Here, we focus on the up-to-date advances in studies on role of iron in atherosclerosis and discuss possible reasons why patients with hereditary hemochromatosis (HH) do not show any increased incidence of atherosclerosis. In addition, we analyze conflicting results concerning the role of iron in atherogenesis from several epidemiological and animal studies. We argue that atherosclerosis is not observed in HH because iron homeostasis in the arterial wall, the actual location of atherosclerosis, is not significantly affected, and support a causal link between iron in the arterial wall and atherosclerosis.

Untargeted Lipidomic Profiling Reveals Lysophosphatidylcholine and Ceramide as Atherosclerotic Risk Factors in apolipoprotein E Knockout Mice

Despite the availability and use of numerous cholesterol-lowering drugs, atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of mortality globally. Many researchers have focused their effort on identifying modified lipoproteins. However, lipid moieties such as lysophosphatidylcholine (LPC) and ceramide (CER) contribute to atherogenic events. LPC and CER both cause endothelial mitochondrial dysfunction, leading to fatty acid and triglyceride (TG) accumulation. In addition, they cause immune cells to differentiate into proinflammatory phenotypes. To uncover alternative therapeutic approaches other than cholesterol- and TG-lowering medications, we conducted untargeted lipidomic investigations to assess the alteration of lipid profiles in apolipoprotein E knockout (apoE^-/-) mouse model, with or without feeding a high-fat diet (HFD). Results indicated that, in addition to hypercholesterolemia and hyperlipidemia, LPC levels were two to four times higher in apoE^-/- mice compared to wild-type mice in C57BL/6 background, regardless of whether they were 8 or 16 weeks old. Sphingomyelin (SM) and CER were elevated three- to five-fold in apoE^-/- mice both at the basal level and after 16 weeks when compared to wild-type mice. After HFD treatment, the difference in CER levels elevated more than ten-fold. Considering the atherogenic properties of LPC and CER, they may also contribute to the early onset of atherosclerosis in apoE^-/- mice. In summary, the HFD-fed apoE^-/- mouse shows elevated LPC and CER contents and is a suitable model for developing LPC- and CER-lowering therapies.

Curaxin CBL0137 inhibits endothelial inflammation and atherogenesis via suppression of the Src-YAP signalling axis

BACKGROUND AND PURPOSE

Atherosclerotic vascular disease is the leading cause of mortality and morbidity worldwide. Our previous study uncovered that endothelium-specific knockdown of YAP suppresses atherogenesis, suggesting that YAP is a promising therapeutic target against atherosclerotic vascular disease. We established a drug screening platform, which aimed to identify new YAP inhibitors for anti-atherosclerotic treatment.

EXPERIMENTAL APPROACH

Drug screening was performed by a luciferase reporter gene assay. RNA sequencing was performed to acquire the transcriptomic profile of CBL0137-treated endothelial cells. We assessed and validated the inhibitory effect of CBL0137 on YAP activity and inflammatory response in HUVECs and HAECs. We evaluated the vasoprotective effect of CBL0137 in vivo against plaque formation in ApoE^-/- mice, using both disturbed flow-induced and chronic western diet-induced atherosclerotic models.

KEY RESULTS

We identified CBL0137 as a novel YAP inhibitor from an FDA drug library. CBL0137 inhibited YAP activity by restraining its phosphorylation at Y357. CBL0137 inhibited YAP activity to repress endothelial inflammation. Mechanistically, CBL0137 suppressed YAP phosphorylation at Y357 via the tyrosine-protein kinase Src. Furthermore, administration of CBL0137 ameliorated endothelial inflammation and the atherogenesis induced by disturbed flow and consumption of an atherogenic diet in ApoE^-/- mice.

CONCLUSION AND IMPLICATIONS

To our knowledge, this is the first study to identify CBL0137 as a novel YAP inhibitor. We have demonstrated that pharmacologically targeting YAP by CBL0137 inhibits atherogenesis. The present results suggest that CBL0137 holds promise as a new drug for the treatment of atherosclerotic vascular disease.

Cardiovascular adverse events in chronic myeloid leukemia patients treated with nilotinib or imatinib: A systematic review, meta-analysis and integrative bioinformatics analysis

OBJECTIVE

The aim of this article is to assess the risk and potential mechanisms of cardiovascular adverse events in patients treated with nilotinib or imatinib by conducting a systematic review, meta-analysis and integrative bioinformatics analysis.

MATERIALS AND METHODS

Three databases were systematically searched for studies published from inception to May 29, 2022. Differential expression analysis and weighted gene coexpression network analysis (WGCNA) were performed to search for modules of genes most associated with cardiotoxicity. Protein-protein interaction (PPI) network analysis was then performed to identify hub genes for the cardiotoxicity of nilotinib. Molecular docking was used to analyze the effects of rosuvastatin and aspirin on these targets.

RESULTS

Patients treated with nilotinib as first-line treatment were associated with a higher risk of CAE (OR = 3.43 [95% CI 2.77-4.25]), CAD (OR = 5.30 [95% CI 3.85-7.29]), ACS (OR 2.7 [95% CI 1.60-4.54]), CVA (OR 5.76 [95% CI 2.84-11.28]), PAOD (OR 5.57 [95% CI 3.26-9.50]) and arrhythmia (OR 2.34 [1.17,4.67]) than those treated with imatinib, while no significant difference was found in the risk of HF (OR 1.40 [95% CI 0.42-4.69]) between the two groups. Patients who were treated with more than 600 mg daily dosage of nilotinib or followed up for more than 5 years had a higher risk of ACS and CVA. IL6, CXCL8, CCL2, SOD2, NFKBIA, and BIRC3 were identified as the top 6 hub genes in the magenta module (human cardiomyocyte samples) and were mainly enriched in the NOD-like receptor signaling pathway, IL-17 signaling pathway, TNF signaling pathway, lipid and atherosclerosis signaling pathway. TYROBP and CSF1R were identified as hub genes in the turquoise module (liver samples from Mus musculus). GSEA results showed that type II diabetes mellitus, B-cell receptor, apoptosis, insulin, natural killer cell mediated cytotoxicity,mTOR, chemokine, and T-cell receptor signaling pathways were related to the higher risk of atherosclerosis caused by nilotinib. Rosuvastatin can effectively bind to most of the hub targets and proteins enriched in the inflammatory pathways above.

CONCLUSION

CML patients who start with nilotinib have a higher risk of CAE than those with imatinib. Atherosclerosis caused by the inflammatory response and glycolipid metabolism disorder is the key mechanism of nilotinib cardiotoxicity. Rosuvastatin may be an effective treatment for the cardiotoxicity of nilotinib.

Non-Mouse Models of Atherosclerosis: Approaches to Exploring the Translational Potential of New Therapies

Cardiovascular disease is the largest single cause of disease-related mortality worldwide and the major underlying pathology is atherosclerosis. Atherosclerosis develops as a complex process of vascular lipid deposition and retention by modified proteoglycans, endothelial dysfunction and unresolved chronic inflammation. There are a multitude of current therapeutic agents, most based on lowering plasma lipid levels, but, overall, they have a lower than optimum level of efficacy and many deaths continue to arise from cardiovascular disease world-wide. To identify and evaluate potential novel cardiovascular drugs, suitable animal models that reproduce human atherosclerosis with a high degree of fidelity are required as essential pre-clinical research tools. Commonly used animal models of atherosclerosis include mice (ApoE-/-, LDLR-/- mice and others), rabbits (WHHL rabbits and others), rats, pigs, hamster, zebrafish and non-human primates. Models based on various wild-type and genetically modified mice have been extensively reviewed but mice may not always be appropriate. Thus, here, we provide an overview of the advantages and shortcomings of various non-mouse animal models of atherosclerotic plaque formation, and plaque rupture, as well as commonly used interventional strategies. Taken together, the combinatorial selection of suitable animal models readily facilitates reproducible and rigorous translational research in discovering and validating novel anti-atherosclerotic drugs.

A novel mouse model of diabetes, atherosclerosis and fatty liver disease using an AAV8-PCSK9-D377Y injection and dietary manipulation in db/db mice

Preclinical mouse models of cardiometabolic diseases are crucial to study the pathological mechanisms of cardiometabolic diseases and to explore potential new therapeutic agents. Using double-knockouts in the background of ApoE^-/- or Ldlr^-/- mice requires an extensive amount of breeding and is costly. A significant breakthrough in atherosclerosis research is the use of AAV8-PCSK9-D377Y (a gain-of-function mutant of PCSK9 which promotes LDLR degradation) injection which can induce hyperlipidemia, increased endothelial stiffness, vascular calcification, aneurysm, and atherosclerotic plaque development in normal C57BL/6J mice. The purpose of this study was to assess the possibility that the injection of AAV8-PCSK9 vectors in db/db mice (a well-established animal model of type 2 diabetes mellitus) produces a novel mouse model of diabetes, atherosclerosis and fatty liver disease to study the pathomechanisms of cardiometabolic disease and its complications. Db/db mice were injected with AAV8-PCSK9-D377Y (AAV8-PCSK9 for simplicity) or AAV8-control and fed with high-cholesterol diets for 8 weeks. Levels of total cholesterol (TC) and triglyceride (TG) were significantly elevated in AAV8-PCSK9-injected mice compared to the controls. AAV8-PCSK9 injection led to increased serum level of PCSK9, serious liver steatosis, hypercholesterolemia and atherosclerotic plaque as determined by aortic arch/roots histopathological staining, with Oil Red O, Masson-trichrome and hematoxylin-eosin staining. RNA sequencing and bioinformatics were used to assess the global gene expression in liver tissues. We conclude that AAV8-PCSK9 injection in db/db mice is a promising and time-efficient approach to induce diabetic atherosclerosis with fatty liver. This mouse model can be a new one to investigate the etiology and therapeutics of atherosclerosis with diabetes and fatty liver beyond the traditional model established in ApoE^-/- mice or LDLR^-/- mice receiving streptozotocin (STZ) injection.

Multiple aspects of lymphatic dysfunction in an ApoE -/- mouse model of hypercholesterolemia

Introduction: Rodent models of cardiovascular disease have uncovered various types of lymphatic vessel dysfunction that occur in association with atherosclerosis, type II diabetes and obesity. Previously, we presented in vivo evidence for impaired lymphatic drainage in apolipoprotein E null (ApoE ^-/- ) mice fed a high fat diet (HFD). Whether this impairment relates to the dysfunction of collecting lymphatics remains an open question. The ApoE ^-/- mouse is a well-established model of cardiovascular disease, in which a diet rich in fat and cholesterol on an ApoE deficient background accelerates the development of hypercholesteremia, atherosclerotic plaques and inflammation of the skin and other tissues. Here, we investigated various aspects of lymphatic function using ex vivo tests of collecting lymphatic vessels from ApoE ^+/+ or ApoE ^-/- mice fed a HFD. Methods: Popliteal collectors were excised from either strain and studied under defined conditions in which we could quantify changes in lymphatic contractile strength, lymph pump output, secondary valve function, and collecting vessel permeability. Results: Our results show that all these aspects of lymphatic vessel function are altered in deleterious ways in this model of hypercholesterolemia. Discussion: These findings extend previous in vivo observations suggesting significant dysfunction of lymphatic endothelial cells and smooth muscle cells from collecting vessels in association with a HFD on an ApoE-deficient background. An implication of our study is that collecting vessel dysfunction in this context may negatively impact the removal of cholesterol by the lymphatic system from the skin and the arterial wall and thereby exacerbate the progression and/or severity of atherosclerosis and associated inflammation.