Small rodent models of atherosclerosis

Towards a Conceptual Framework to Better Understand the Advantages and Limitations of Model Organisms

Model organisms (MO) are widely used in neuroscience to study brain processes, behavior, and the biological foundation of human diseases. However, the use of MO has also been criticized for low reliability and insufficient success rate in the development of therapeutic approaches, because the success of MO use also led to overoptimistic and simplistic applications, which sometimes resulted in wrong conclusions. Here, we develop a conceptual framework of MO to support scientists in their practical work and to foster discussions about their power and limitations. For this purpose, we take advantage of concepts developed in the philosophy of science and adjust them for practical application by neuroscientists. We suggest that MO can be best understood as tools that are used to gain information about a group of species or a phenomenon in a species of interest. These learning processes are made possible by some properties of MO, which facilitate the process of acquisition of understanding or provide practical advantages, and the possibility to transfer information between species. However, residual uncertainty in the reliability of information transfer remains, and incorrect generalizations can be side-effects of epistemic benefits, which we consider as representational and epistemic risks. This suggests that to use MO most effectively, scientists should analyze the similarity relation between the involved species, weigh advantages and risks of certain epistemic benefits, and invest in carefully designed validation experiments. Altogether, our analysis illustrates how scientists can benefit from philosophical concepts for their research practice.

Natural and Synthetic LDL-Based Imaging Probes for the Detection of Atherosclerotic Plaques

Low-density lipoprotein (LDL) is the primary natural carrier of lipids in the bloodstream and plays a central role in the development of atherosclerosis. By leveraging LDL's natural tendency to accumulate at sites of plaque formation, LDL can be employed as a carrier to selectively deliver the imaging probes to efficiently detect atherosclerotic plaques. In our previous studies, we reported several LDL-based magnetic resonance imaging contrast agents (MRI-CAs) formed by modifying natural LDL (nLDL) or developing LDL-mimetic (synthetic LDL, sLDL) from lipid nanoparticles (LNPs) utilizing chemical reactions on the nanoparticle surface, including preliminary MRI tests. In this study, we report the in vivo biological functionality of these LDLs (both nLDL and sLDL)-based Gd(III)-based contrast agents (GBCAs) by conducting detailed in vivo studies on two types of atherosclerosis murine models, namely, apoE -/- and LDLr -/- . We provide more comprehensive MRI data accompanied by ex vivo results, including microscopic analysis of aorta segments for LDL accumulation and whole-body cryoVIZ analysis for biodistribution of the probe. We also tested in vitro cellular internalization of sLDL on two cell lines (RAW 264.7 and THP-1), which are derived from macrophages and monocytes, respectively, in order to observe sLDL uptake by macrophages, which are often present at the vulnerable types of atherosclerotic plaques. In conclusion, our current study demonstrates that modified LDLs-both nLDL and sLDL-facilitate MRI detection of atheroplaques by efficient uptake by macrophages. Taken together with the high loading capacity of Gd(III)-chelate molecules on LDL, especially sLDL, the LDL-based MRI contrast agents reported here hold significant potential for the early detection of atherosclerosis, including vulnerable ones, and should be useful for preventive diagnosis strategies.

Vitisin A Outperforms Cyanidin-3-O-Glucoside in Triglyceride Reduction by Modulating Hepatic Lipogenesis and Fatty Acid β-Oxidation

Pyranoanthocyanins exhibit greater bioactivity compared to monomeric anthocyanins, yet the lipid-lowering effects of pyranoanthocyanin Vitisin A, a primary derivative found in aged red wines, have not been extensively studied in vivo. This study evaluated the triglyceride-lowering effects of Vitisin A and its anthocyanin counterpart Cyanidin-3-O-glucoside (C3G) in both free fatty acid -induced HepG2 cells and high-fat diet-fed ApoE-/- mice, with a focus on their roles in lipid metabolism. In vitro, Vitisin A significantly reduced triglyceride levels and lipid accumulation in HepG2 cells compared to C3G at equivalent concentrate. In vivo, dietary supplementation with 100 mg/kg of Vitisin A reduced body weight gain and plasma triglyceride levels by 19.6% and 29.5%, respectively, whereas no significant effects were observed with C3G. Mechanistically, Vitisin A markedly inhibited hepatic de novo lipogenesis (DNL) by activating the AMPK/ACC signaling pathway and downregulating FASN expression. Concurrently, Vitisin A enhanced fatty acid β-oxidation more robustly than C3G by upregulating CPT-1A via AMPK/SIRT1/PGC-1α and PPAR-α/PGC-1α pathways. Both Vitisin A and C3G driving peroxisomal β-oxidation of very-long-chain fatty acids. In summary, Vitisin A demonstrated superior triglyceride-lowering effects compared to C3G, primarily through dual mechanisms of inhibiting hepatic DNL and enhancing fatty acid β-oxidation.

Sphingolipid metabolites involved in the pathogenesis of atherosclerosis: perspectives on sphingolipids in atherosclerosis

Atherosclerosis, with its complex pathogenesis, is a leading underlying cause of many cardiovascular diseases, which are increasingly prevalent in the population. Sphingolipids play an important role in the development of atherosclerosis. Key metabolites and enzymes in sphingolipid metabolism influence the pathogenesis of atherosclerosis in a variety of ways, including inflammatory responses and oxidative stress. Thus, an investigation of sphingolipid metabolism-related metabolites and key enzymes may provide novel insights and treatment targets for atherosclerosis. This review discusses various mechanisms and research progress on the relationship between various sphingolipid metabolites, related enzymes, and atherosclerosis. Finally, we look into the future research direction of phytosphingolipids.

Identification of Senkyunolide I as a novel modulator of hepatic steatosis and PPARα signaling in zebrafish and hamster models

ETHNOPHARMACOLOGICAL RELEVANCE

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of liver-related morbidity and mortality, with hepatic steatosis being the hallmark symptom. Salvia miltiorrhiza Bunge (Smil, Dan-Shen) and Ligusticum striatum DC (Lstr, Chuan-Xiong) are commonly used to treat cardiovascular diseases and have the potential to regulate lipid metabolism. However, whether Smil/Lstr combo can be used to treat NAFLD and the mechanisms underlying its lipid-regulating properties remain unclear.

PURPOSE

To assess the feasibility and reliability of a short-term high-fat diet (HFD) induced zebrafish model for evaluating hepatic steatosis phenotype and to investigate the liver lipid-lowering effects of Smil/Lstr, as well as its active components.

METHODS

The phenotypic alterations of liver and multiple other organ systems were examined in the HFD zebrafish model using fluorescence imaging and histochemistry. The liver-specific lipid-lowering effects of Smil/Lstr combo were evaluated endogenously. The active molecules and functional mechanisms were further explored in zebrafish, human hepatocytes, and hamster models.

RESULTS

In 5-day HFD zebrafish, significant lipid accumulation was detected in the blood vessels and the liver, as evidenced by increased staining with Oil Red O and fluorescent lipid probes. Hepatic hypertrophy was observed in the model, along with macrovesicular steatosis. Smil/Lstr combo administration effectively restored the lipid profile and alleviated hepatic hypertrophy in the HFD zebrafish. In oleic-acid stimulated hepatocytes, Smil/Lstr combo markedly reduced lipid accumulation and cell damage. Subsequently, based on zebrafish phenotypic screening, the natural phthalide senkyunolide I (SEI) was identified as a major molecule mediating the lipid-lowering activities of Smil/Lstr combo in the liver. Moreover, SEI upregulated the expression of the lipid metabolism regulator PPARα and downregulated fatty acid translocase CD36, while a PPARα antagonist sufficiently blocked the regulatory effect of SEI on hepatic steatosis. Finally, the roles of SEI on hepatic lipid accumulation and PPARα signaling were further verified in the hamster model.

CONCLUSIONS

We proposed a zebrafish-based screening strategy for modulators of hepatic steatosis and discovered the regulatory roles of Smil/Lstr combo and its component SEI on liver lipid accumulation and PPARα signaling, suggesting their potential value as novel candidates for NAFLD treatment.

Rodent model of metabolic dysfunction-associated fatty liver disease: a systematic review

Although significant progress has been made in developing preclinical models for metabolic dysfunction-associated steatotic liver disease (MASLD), few have encapsulated the essential biological and clinical outcome elements reflective of the human condition. We conducted a comprehensive literature review of English-language original research articles published from 1990 to 2023, sourced from PubMed, Embase, and Web of Science, aiming to collate studies that provided a comparative analysis of physiological, metabolic, and hepatic histological characteristics between MASLD models and control groups. The establishment of a robust metabolic dysfunction-associated steatotic liver rodent model hinges on various factors, including animal species and strains, sex, induction agents and methodologies, and the duration of induction. Through this review, we aim to guide researchers in selecting suitable induction methods and animal species for constructing preclinical models aligned with their specific research objectives and laboratory conditions. Future studies should strive to develop simple, reliable, and reproducible models, considering the model's sensitivity to factors such as light-dark cycles, housing conditions, and environmental temperature. Additionally, the potential of diverse in vitro models, including 3D models and liver organ technology, warrants further exploration as valuable tools for unraveling the cellular mechanisms underlying fatty liver disease.

Novel insights of disulfidptosis-mediated immune microenvironment regulation in atherosclerosis based on bioinformatics analyses

Atherosclerosis (AS) is the leading cause of coronary heart disease, which is the primary cause of death worldwide. Recent studies have identified disulfidptosis as a new type of cell death that may be involved in onset and development of many diseases. However, the role of disulfidptosis in AS is not clear. In this study, bioinformatics analysis and experiments in vivo and in vitro were performed to evaluate the potential relationship between disulfidptosis and AS. AS-related sequencing data were obtained from the Gene Expression Omnibus (GEO). Bioinformatics techniques were used to evaluate differentially expressed genes (DEGs) associated with disulfidptosis-related AS. Hub genes were screened using least absolute shrinkage and selection operator (LASSO) and random forests (RF) methods. In addition, we established a foam cell model in vitro and an AS mouse model in vivo to verify the expressions of hub genes. In addition, we constructed a diagnostic nomogram with hub genes to predict progression of AS. Finally, the consensus clustering method was used to establish two different subtypes, and associations between subtypes and immunity were explored. As the results, 9 disulfidptosis-related AS DEGs were identified from GSE28829 and GSE43292 datasets. Evaluation of DEGs using LASSO and RF methods resulted in identification of 4 hub genes (CAPZB, DSTN, MYL6, PDLIM1), which were analyzed for diagnostic value using ROC curve analysis and verified in vitro and in vivo. Furthermore, a nomogram including hub genes was established that accurately predicted the occurrence of AS. The consensus clustering algorithm was used to separate patients with early atherosclerotic plaques and patients with advanced atherosclerotic plaques into two disulfidptosis subtypes. Cluster B displayed higher levels of infiltrating immune cells, which indicated that patients in cluster B may have a positive immune response for progression of AS. In summary, disulfidptosis-related genes including CAPZB, DSTN, MYL6, and PDLIM1 may be diagnostic markers and therapeutic targets for AS. In addition, these genes are closely related to immune cells, which may inform immunotherapy for AS.

Exploration of anti-atherosclerotic activity of 1,8-cineole through network pharmacology, molecular docking, and in vivo efficacy studies in high-fat-diet-induced atherosclerosis in hamsters

The anti-atherogenic potential of liver X receptors (LXRs) has been attributed to their inhibitory role in macrophage-mediated inflammation and promotion of reverse cholesterol transport. This study aimed to evaluate the efficacy of an LXR agonist, 1,8-cineole (Eucalyptol), in atherosclerosis through network pharmacology, molecular docking, and in vivo efficacy studies in high-fat-diet-induced atherosclerosis in hamsters. Network pharmacology analysis was performed by identifying potential targets of 1,8-Cineole and atherosclerosis, followed by the construction of component-target-disease and protein-protein interaction networks. Gene Ontology and KEGG pathway enrichment analysis of targets were performed. The top 5 targets were selected for molecular docking studies. Atherosclerosis was induced in male Golden Syrian hamsters, and the results of network pharmacology were verified. Fifty-one overlapped targets were identified for 1,8-cineole and atherosclerosis. In the protein-protein interaction studies, the top 5 ranked proteins were PPARG, FXR, ABCA-1, ABCG1, and LXRΑ. KEGG pathway analysis and molecular docking showed that ABCA-1 and LXRΑ were correlated in atherosclerosis. Animal studies showed amelioration of atherosclerotic lesions in the aorta of animals treated with 1,8-cineole compared to disease control aortas. A dose-dependent attenuation in ABCA-1 levels and inflammatory markers was observed in animals treated with 1,8-cineole, comparable to its levels in normal animals. In conclusion, 1,8-cineole showed anti-atherosclerotic effects in Golden Syrian hamsters via LXRΑ-induced ABCA-1 overexpression.

Assessment of therapeutic efficacy of adipose tissue-derived mesenchymal stem cells administration in hyperlipidemia-induced aortic atherosclerosis in adult male albino rats

Atherosclerosis (AS) is a common disease seriously detrimental to human health. AS is a chronic progressive disease related to inflammatory reactions. The present study aimed to characterize and evaluate the effects of adipose tissue stem cells (ADSCs) in high-fat diet-induced atherosclerosis in a rat model. The present study comprises thirty-six rats and they were divided into three groups: the control group, the high-fat diet (HFD) group; which received a high-fat diet, and the high-fat diet + stem cells (HFD+SC) group; which was fed with a high-fat diet along with the administration of intravenous ADSCs. Food was given to the animals for 20 weeks to establish dyslipidemia models. After 20 weeks, animals were sacrificed by cervical dislocation; blood was collected to measure total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL); aortae were collected to detect morphologic changes. Rats of the HFD group showed a significant increase in body weight (B.Wt), altered lipid profile increased expression of inducible nitric oxide synthase (iNOS), and decreased expression of endothelial nitric oxide synthase (eNOS). However, in HFD+SC there was a significant decrease in body weight gain and an improvement in lipid profile. Histopathological and ultrastructural variations observed in the aorta of the HFD group when treated with ADSCs showed preserved normal histological architecture and reduced atherosclerosis compared with the HFD group. This was evidenced by laboratory, histological, immunohistochemical, and morphometric studies. Thus, ADSCs reduced TC, TG, and LDL, reduced the expression of iNOS, and increased the expression of eNOS. The high-fat diet was likely to cause damage to the wall of blood vessels. Systemically transplanted ADSCs could home to the aorta, and further protect the aorta from HFD-induced damage.

The rat as an animal model in chronic wound research: An update

The increasing global prevalence of chronic wounds underscores the growing importance of developing effective animal models for their study. This review offers a critical evaluation of the strengths and limitations of rat models frequently employed in chronic wound research and proposes potential improvements. It explores these models in the context of key comorbidities, including diabetes, venous and arterial insufficiency, pressure-induced blood flow obstruction, and infections. Additionally, the review examines important wound factors including age, sex, smoking, and the impact of anesthetic and analgesic drugs, acknowledging their substantial effects on research outcomes. A thorough understanding of these variables is crucial for refining animal models and can provide valuable insights for future research endeavors.

Syndecan-1 as a predictor of vulnerable atherosclerotic plaques

Aims

Cardiovascular disease remains a major global health concern, with atherosclerosis (AS) being a significant contributor. Vulnerable plaques play a critical role in acute cardiovascular events. Syndecan-1 (SDC-1), a vital membrane proteoglycan in the vascular endothelial glycocalyx, is believed to be associated with plaque progression. However, its precise relationship with severity and vulnerability of atherosclerotic plaque remains unclear. This study aimed to investigate SDC-1 expression and its potential correlation with plaque vulnerability in ApoE-/- atherosclerosis mouse model.

Methods and results

Eight-week-old mice were induced into the AS model using a high-fat diet (HFD) and/or partial ligation of the left common carotid artery (PLCA), with a chow diet (CD) control group. After 16 weeks, plaques in the aortic root showed the following order: HFD + PLCA group > HFD group > CD + PLCA group > CD group. Immunohistochemistry revealed heightened accumulation of lipid/foam cells and CD68-labeled macrophages in the plaques, elevated vascular endothelial growth factor (VEGF), and matrix Metalloproteinase-9 (MMP-9) in the HFD + PLCA group's plaques, along with reduced collagen and α-SMA-labeled smooth muscle cells, resulting in the highest vulnerability index value. Immunohistofluorescence analysis of frozen plaque sections showed significantly higher SDC-1 expression in the AS mice group compared to the CD group, both positively correlated with plaque vulnerability. Serum analysis demonstrated elevated levels of SDC1, sphingosine 1-phosphate (S1P), and VEGF-A in the AS mice, all positively correlated with plaque vulnerability. Multivariate analysis identified SDC1 as an independent predictor of plaque vulnerability.

Conclusion

This study enhances our understanding of plaque vulnerability mechanisms and presents SDC1 as a potential biomarker for atherosclerosis. These findings underscore the importance of addressing modifiable risk factors, such as diet and hemodynamics and suggest the utility of serum SDC1 as a valuable clinical marker. Ultimately, these insights may lead to more effective strategies in combating cardiovascular diseases and improving patient outcomes.

Comparative studies between humans and golden Syrian hamsters via thromboelastography

BACKGROUND

Thromboelastography (TEG) is a widely utilized clinical testing method for real-time monitoring of platelet function and the thrombosis process. Lipid metabolism disorders are crucial risk factors for thrombosis. The lipid metabolism characteristics of hamsters resemble those of humans more closely than mice and rats, and their relatively large blood volume makes them suitable for studying the mechanisms of thrombosis related to plasma lipid mechanisms. Whole blood samples from golden Syrian hamsters and healthy humans were obtained following standard clinical procedures. TEG was employed to evaluate coagulation factor function, fibrinogen (Fib) function, platelet function, and the fibrinolytic system.

METHODS

The whole blood from hamster or healthy human was isolated following the clinical procedure, and TEG was employed to evaluate the coagulation factor function, Fib function, platelet function, and fibrinolytic system. Coagulation analysis used ACLTOP750 automatic coagulation analysis pipeline. Blood routine testing used XN-2000 automatic blood analyzer.

RESULTS

TEG parameters revealed that hamsters exhibited stronger coagulation factor function than humans (reaction time [R], p = 0.0117), with stronger Fib function (alpha angle, p < 0.0001; K-time [K], p < 0.0001). Platelet function did not differ significantly (maximum amplitude [MA], p = 0.077). Hamsters displayed higher coagulation status than humans (coagulation index [CI], p = 0.0023), and the rate of blood clot dissolution in hamsters differed from that in humans (percentage lysis 30 min after MA, p = 0.02). Coagulation analysis parameters indicated that prothrombin time (PT) and activated partial thromboplastin time (APTT) were faster in hamsters than in humans (PT, p = 0.0014; APTT, p = 0.03), whereas the Fib content was significantly lower in hamsters than in humans (p < 0.0001). No significant difference was observed in thrombin time (p = 0.1949).

CONCLUSIONS

In summary, TEG could be used to evaluate thrombosis and bleeding parameters in whole blood samples from hamsters. The platelet function of hamsters closely resembled that of humans, whereas their coagulation function was significantly stronger.

β-hydroxybutyrate and ischemic stroke: roles and mechanisms

Stroke is a significant global burden, causing extensive morbidity and mortality. In metabolic states where glucose is limited, ketone bodies, predominantly β-hydroxybutyrate (BHB), act as alternative fuel sources. Elevated levels of BHB have been found in the ischemic hemispheres of animal models of stroke, supporting its role in the pathophysiology of cerebral ischemia. Clinically, higher serum and urinary BHB concentrations have been associated with adverse outcomes in ischemic stroke, highlighting its potential utility as a prognostic biomarker. In both animal and cellular models, exogenous BHB administration has exhibited neuroprotective effects, reduction of infarct size, and improvement of neurological outcomes. In this review, we focus on the role of BHB before and after ischemic stroke, with an emphasis on the therapeutic potential and mechanisms of ketone administration after ischemic stroke.

Hawthorn leaf flavonoids alleviate the deterioration of atherosclerosis by inhibiting SCAP-SREBP2-LDLR pathway through sPLA2-ⅡA signaling in macrophages in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Hawthorn leaves are a combination of the dried leaves of the Rosaceae plants, i.e., Crataegus pinnatifida Bge. or Crataegus pinnatifida Bge. var. major N. E. Br., is primarily cultivated in East Asia, North America, and Europe. hawthorn leaf flavonoids (HLF) are the main part of extraction. The HLF have demonstrated potential in preventing hypertension, inflammation, hyperlipidemia, and atherosclerosis. However, the potential pharmacological mechanism behind its anti-atherosclerotic effect has yet to be explored.

AIM OF THE STUDY

The in vivo and in vitro effects of HLF on lipid-mediated foam cell formation were investigated, with a specific focus on the levels of secreted phospholipase A2 type IIA (sPLA2-II A) in macrophage cells.

MATERIALS AND METHODS

The primary constituents of HLF were analyzed using ultra-high performance liquid chromatography and liquid chromatography-tandem mass spectrometry. In vivo, HLF, at concentrations of 5 mg/kg, 20 mg/kg, and 40 mg/kg, were administered to apolipoprotein E knockout mice (ApoE-/-) fed by high-fat diet (HFD) for 16 weeks. Aorta and serum samples were collected to identify lesion areas and lipids through mass spectrometry analysis to dissect the pathological process. RAW264.7 cells were incubated with oxidized low-density lipoprotein (ox-LDL) alone, or ox-LDL combined with different doses of HLF (100, 50, and 25 μg/ml), or ox-LDL plus 24-h sPLA2-IIA inhibitors, for cell biology analysis. Lipids and inflammatory cytokines were detected using biochemical analyzers and ELISA, while plaque size and collagen content of plaque were assessed by HE and the Masson staining of the aorta. The lipid deposition in macrophages was observed by Oil Red O staining. The expression of sPLA2-IIA and SCAP-SREBP2-LDLR was determined by RT-qPCR and Western blot analysis.

RESULTS

The chemical profile of HLF was studied using UPLC-Q-TOF-MS/MS, allowing the tentative identification of 20 compounds, comprising 1 phenolic acid, 9 flavonols and 10 flavones, including isovitexin, vitexin-4″-O-glucoside, quercetin-3-O-robibioside, rutin, vitexin-2″-O-rhamnoside, quercetin, etc. HLF decreased total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and non-high-density lipoprotein cholesterol (non-HDL-C) levels in ApoE-/- mice (P < 0.05), reduced ox-LDL uptake, inhibited level of inflammatory factors, such as IL-6, IL-8, TNF-α, and IL-1ꞵ (P < 0.001), and alleviated aortic plaques with a thicker fibrous cap. HLF effectively attenuated foam cell formation in ox-LDL-treated RAW264.7 macrophages, and reduced levels of intracellular TC, free cholesterol (FC), cholesteryl ester (CE), IL-6, TNF-α, and IL-1β (P < 0.001). In both in vivo and in vitro experiments, HLF significantly downregulated the expression of sPLA2-IIA, SCAP, SREBP2, LDLR, HMGCR, and LOX-1 (P < 0.05). Furthermore, sPLA2-IIA inhibitor effectively mitigated inflammatory release in RAW264.7 macrophages and regulated SCAP-SREBP2-LDLR signaling pathway by inhibiting sPLA2-IIA secretion (P < 0.05).

CONCLUSION

HLF exerted a protective effect against atherosclerosis through inhibiting sPLA2-IIA to diminish SCAP-SREBP2-LDLR signaling pathway, to reduce LDL uptake caused foam cell formation, and to slow down the progression of atherosclerosis in mice.

In vitro and in vivo exposure of endothelial cells to dibutyl phthalate promotes monocyte adhesion

The effect of endothelial cells' exposure to dibutyl phthalate (DBP) on monocyte adhesion is largely unknown. We evaluated monocyte adhesion to DBP-exposed endothelial cells by combining three approaches: short-term exposure (24 h) of EA.hy926 cells to 10-6, 10-5, and 10-4 M DBP, long-term exposure (12 weeks) of EA.hy926 cells to 10-9, 10-8, and 10-7 M DBP, and exposure of rats (28 and 90 days) to 100, 500, and 5000 mg DBP/kg food. Monocyte adhesion to human EA.hy926 and rat aortic endothelial cells, expression of selected cellular adhesion molecules and chemokines, and the involvement of extracellular signal-regulated kinase 1/2 (ERK1/2) were analyzed. We observed increased monocyte adhesion to DBP-exposed EA.hy926 cells in vitro and to rat aortic endothelium ex vivo. ERK1/2 inhibitor prevented monocyte adhesion to DBP-exposed EA.hy926 cells in short-term exposure experiments. Increased ERK1/2 phosphorylation in rat aortic endothelium and transient decrease in ERK1/2 activation following long-term exposure of EA.hy926 cells to DBP were also observed. In summary, exposure of endothelial cells to DBP promotes monocyte adhesion, thus suggesting a possible role for this phthalate in the development of atherosclerosis. ERK1/2 signaling could be the mediator of monocyte adhesion to DBP-exposed endothelial cells, but only after short-term high-level exposure.

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.

Recapitulating familial hypercholesterolemia in a mouse model by knock-in patient-specific LDLR mutation

Familial hypercholesterolemia (FH) is one of the most prevalent monogenetic disorders leading to cardiovascular disease (CVD) worldwide. Mutations in Ldlr, encoding a membrane-spanning protein, account for the majority of FH cases. No effective and safe clinical treatments are available for FH. Adenine base editor (ABE)-mediated molecular therapy is a promising therapeutic strategy to treat genetic diseases caused by point mutations, with evidence of successful treatment in mouse disease models. However, due to the differences in the genomes between mice and humans, ABE with specific sgRNA, a key gene correction component, cannot be directly used to treat FH patients. Thus, we generated a knock-in mouse model harboring the partial patient-specific fragment and including the Ldlr W490X mutation. LdlrW490X/W490X mice recapitulated cholesterol metabolic disorder and clinical manifestations of atherosclerosis associated with FH patients, including high plasma low-density lipoprotein cholesterol levels and lipid deposition in aortic vessels. Additionally, we showed that the mutant Ldlr gene could be repaired using ABE with the cellular model. Taken together, these results pave the way for ABE-mediated molecular therapy for FH.

Increased LL37 in psoriasis and other inflammatory disorders promotes LDL uptake and atherosclerosis

Patients with chronic inflammatory disorders such as psoriasis have an increased risk of cardiovascular disease and elevated levels of LL37, a cathelicidin host defense peptide that has both antimicrobial and proinflammatory properties. To explore whether LL37 could contribute to the risk of heart disease, we examined its effects on lipoprotein metabolism and show that LL37 enhanced LDL uptake in macrophages through the LDL receptor (LDLR), scavenger receptor class B member 1 (SR-B1), and CD36. This interaction led to increased cytosolic cholesterol in macrophages and changes in expression of lipid metabolism genes consistent with increased cholesterol uptake. Structure-function analysis and synchrotron small-angle x-ray scattering showed structural determinants of the LL37-LDL complex that underlie its ability to bind its receptors and promote uptake. This function of LDL uptake is unique to cathelicidins from humans and some primates and was not observed with cathelicidins from mice or rabbits. Notably, Apoe-/- mice expressing LL37 developed larger atheroma plaques than did control mice, and a positive correlation between plasma LL37 and oxidized phospholipid on apolipoprotein B (OxPL-apoB) levels was observed in individuals with cardiovascular disease. These findings provide evidence that LDL uptake can be increased via interaction with LL37 and may explain the increased risk of cardiovascular disease associated with chronic inflammatory disorders.

Ketosis prevents abdominal aortic aneurysm rupture through C-C chemokine receptor type 2 downregulation and enhanced extracellular matrix balance

Abdominal aortic aneurysms (AAAs) are prevalent with aging, and AAA rupture is associated with increased mortality. There is currently no effective medical therapy to prevent AAA rupture. The monocyte chemoattractant protein (MCP-1)/C-C chemokine receptor type 2 (CCR2) axis critically regulates AAA inflammation, matrix-metalloproteinase (MMP) production, and extracellular matrix (ECM) stability. We therefore hypothesized that a diet intervention that can modulate CCR2 axis may therapeutically impact AAA risk of rupture. Since ketone bodies (KBs) can trigger repair mechanisms in response to inflammation, we evaluated whether systemic ketosis in vivo could reduce CCR2 and AAA progression. Male Sprague-Dawley rats underwent surgical AAA formation using porcine pancreatic elastase and received daily β-aminopropionitrile to promote AAA rupture. Rats with AAAs received either a standard diet, ketogenic diet (KD), or exogenous KBs (EKB). Rats receiving KD and EKB reached a state of ketosis and had significant reduction in AAA expansion and incidence of rupture. Ketosis also led to significantly reduced aortic CCR2 content, improved MMP balance, and reduced ECM degradation. Consistent with these findings, we also observed that Ccr2-/- mice have significantly reduced AAA expansion and rupture. In summary, this study demonstrates that CCR2 is essential for AAA expansion, and that its modulation with ketosis can reduce AAA pathology. This provides an impetus for future clinical studies that will evaluate the impact of ketosis on human AAA disease.

Targeted mutation and inactivation of the kinesin light chain 3 protein-encoding gene have no impact on mouse fertility†

The kinesin light chain 3 protein (KLC3) is the only member of the kinesin light chain protein family that was identified in post-meiotic mouse male germ cells. It plays a role in the formation of the sperm midpiece through its association with both spermatid mitochondria and outer dense fibers (ODF). Previous studies showed a significant correlation between its expression level and sperm motility and quantitative semen parameters in humans, while the overexpression of a KLC3-mutant protein unable to bind ODF also affected the same traits in mice. To further assess the role of KLC3 in fertility, we used CRISPR/Cas9 genome editing in mice and investigated the phenotypes induced by the invalidation of the gene or of a functional domain of the protein. Both approaches gave similar results, i.e. no detectable change in male or female fertility. Testis histology, litter size and sperm count were not altered. Apart from the line-dependent alterations of Klc3 mRNA levels, testicular transcriptome analysis did not reveal any other changes in the genes tested. Western analysis supported the absence of KLC3 in the gonads of males homozygous for the inactivating mutation and a strong decrease in expression in males homozygous for the allele lacking one out of the five tetratricopeptide repeats. Overall, these observations raise questions about the supposedly critical role of this kinesin in reproduction, at least in mice where its gene mutation or inactivation did not translate into fertility impairment.

The amelioration of a purified Pleurotus abieticola polysaccharide on atherosclerosis in ApoE-/- mice

In this study, a polysaccharide known as PAPS2 was eluted from Pleurotus abieticola fruiting bodies using 0.1 M NaCl solutions. PAPS2 has a Mw of 19.64 kDa and its backbone is mainly composed of →6)-α-D-Galp-(1→, →6)-β-D-Glcp-(1→ and →2,6)-α-D-Galp-(1→ residues, and its branches mainly end with β-D-Manp-(1→, which is attached at C2 of →2,6)-α-D-Galp-(1→. PAPS2 elicited several effects in high-fat diet (HFD)-fed ApoE-/- mice. It significantly reduced the body weight, liver index, and serum levels of total cholesterol (TC) and triglycerides (TGs), and it alleviated lipid accumulation in the aorta. Intestinal microflora analysis showed that PAPS2 suppressed the abundances of Adlercreutzia, Turicibacter, and Helicobacter and enriched that of Roseburia. It also influenced lipid metabolism, suggesting that it reduced the levels of TGs, lysophosphatidylcholine (LPC), phosphatidylcholine (PC), and ceramide (Cer). Moreover, it suppressed oxidative response by increasing nuclear factor erythroid 2 (Nrf2)-related factor expression and activating the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) to reduce the level of reactive oxygen species (ROS). Meanwhile, it showed anti-inflammatory effects partially related to the inhibition of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling induced by lipopolysaccharide (LPS) in RAW 264.7 cells, as well as in the aorta of HFD-fed ApoE-/- mice. This study provides experimental evidence of the auxiliary applicability of PAPS2 in atherosclerosis treatment.

Hydroxytyrosol Induces Dyslipidemia in an ApoB100 Humanized Mouse Model

SCOPE

Extra virgin olive oil has numerous cardiopreventive effects, largely due to its high content of (poly)phenols such as hydroxytyrosol (HT). However, some animal studies suggest that its excessive consumption may alter systemic lipoprotein metabolism. Because human lipoprotein metabolism differs from that of rodents, this study examines the effects of HT in a humanized mouse model that approximates human lipoprotein metabolism.

METHODS AND RESULTS

Mice are treated as follows: control diet or diet enriched with HT. Serum lipids and lipoproteins are determined after 4 and 8 weeks. We also analyzed the regulation of various genes and miRNA by HT, using microarrays and bioinformatic analysis. An increase in body weight is found after supplementation with HT, although food intake was similar in both groups. In addition, HT induced the accumulation of triacylglycerols but not cholesterol in different tissues. Systemic dyslipidemia after HT supplementation and impaired glucose metabolism are observed. Finally, HT modulates the expression of genes related to lipid metabolism, such as Pltp or Lpl.

CONCLUSION

HT supplementation induces systemic dyslipidemia and impaired glucose metabolism in humanized mice. Although the numerous health-promoting effects of HT far outweigh these potential adverse effects, further carefully conducted studies are needed.

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.

Promoting reverse cholesterol transport contributes to the amelioration of atherosclerosis by paeoniflorin

Reverse cholesterol transport (RCT) offers a practical approach to mitigating atherosclerosis. Paeoniflorin, a monoterpenoid glycoside found in plants of the Paeoniaceae family, has shown various effects on cardiovascular and liver diseases. Nevertheless, its impact on atherosclerosis in vivo remains poorly understood. The objective of this study is to examine the effect of paeoniflorin on atherosclerosis using apolipoprotein E-deficient (ApoE-/-) mice and explore the underlying mechanisms, with a specific focus on its modulation of RCT. ApoE-/- mice were continuously administered paeoniflorin by gavage for three months. We assessed lipid parameters in serum and examined pathological changes and gene expressions related to RCT pathways in the aorta, liver, and intestine. In an in vitro study, we utilized RAW264.7 macrophages to investigate the inhibitory effect of paeoniflorin on foam cell formation and its potential to promote RCT. The results revealed that paeoniflorin reduced atherosclerosis, alleviated hyperlipidemia, and mitigated hepatic steatosis. Paeoniflorin may promote RCT by stimulating cholesterol efflux from macrophages via the liver X receptor alpha pathway, enhancing serum high-density lipoprotein cholesterol and apolipoprotein A-I levels, and regulating key genes in hepatic and intestinal RCT. Additionally, treatment ApoE-/- mice with paeoniflorin suppressed the expression of inflammation-related genes, including CD68, tumor necrosis factor alpha, and monocyte chemoattractant protein-1, and mitigated oxidative stress in both the aorta and liver. Our results indicated that paeoniflorin has the potential to be a more effective and safer treatment for atherosclerosis, thanks to its promotion of RCT and its anti-inflammatory and anti-oxidative effects.

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.

DL-3-n-butylphthalide improves the endothelium-dependent vasodilation in high-fat diet-fed ApoE-/- mice via suppressing inflammation, endothelial necroptosis and apoptosis

Impaired endothelium-dependent vasodilation in atherosclerosis is a high-risk factor for myocardial infarction and ischemic stroke, and inflammation, necroptosis and apoptosis contribute to endothelial dysfunction in atherosclerosis. Although DL-3-n-butylphthalide (NBP) has been widely used in treating ischemic stroke, its effect on endothelium-dependent vasodilation remains unknown. This study aims to explore whether NBP is able to improve endothelium-dependent vasodilation in atherosclerosis and the underlying mechanisms. Male ApoE-/- mice were fed with a high-fat diet (HFD) for 9-16 weeks to establish a model of atherosclerosis. NBP were given to the mice after eating HFD for 6 weeks and atorvastatin served as a positive control. The endothelium-dependent vasodilation, the blood flow velocity, the atherosclerotic lesion area, the serum levels of lipids, inflammatory cytokines and necroptosis-relevant proteins (RIPK1, RIPK3 and MLKL), and the endothelial necroptosis and apoptosis within the aorta were measured. Human umbilical vein endothelial cells (HUVECs) were incubated with oxidized low-density lipoprotein (ox-LDL) for 48 h to mimic endothelial injury in atherosclerosis, lactate dehydrogenase release, the ratio of necroptosis and apoptosis and the expression of necroptosis-relevant proteins were examined. Similar to atorvastatin, NBP improves endothelium-dependent vasodilation, decreases aortic flow velocity and reduces atherosclerotic lesion area in HFD-fed ApoE-/- mice, concomitant with a reduction in serum lipids, inflammatory cytokines and necroptosis-relevant proteins, and endothelial necroptosis and apoptosis. Consistently, NBP inhibited necroptosis and apoptosis in ox-LDL-treated HUVECs. Based on these observations, we conclude that NBP exerts beneficial effects on improving the endothelium-dependent vasodilation in atherosclerosis via suppressing inflammation, endothelial necroptosis and apoptosis.

The Greatly Under-Represented Role of Smooth Muscle Cells in Atherosclerosis

PURPOSE OF REVIEW

This article summarizes previous and recent research on the fundamental role of arterial smooth muscle cells (SMCs) as drivers of initial and, along with macrophages, later stages of human atherosclerosis.

RECENT FINDINGS

Studies using human tissues and SMC lineage-tracing mice have reinforced earlier observations that SMCs drive initial atherogenesis in humans and contribute a multitude of phenotypes including foam cell formation hitherto attributed primarily to macrophages in atherosclerosis. Arterial smooth muscle cells (SMCs) are the primary cell type in human pre-atherosclerotic intima and are responsible for the retention of lipoproteins that drive the development of atherosclerosis. Despite this, images of atherogenesis still depict the process as initially devoid of SMCs, primarily macrophage driven, and indicate only relatively minor roles such as fibrous cap formation to intimal SMCs. This review summarizes historical and recent observations regarding the importance of SMCs in the formation of a pre-atherosclerotic intima, initial and later foam cell formation, and the phenotypic changes that give rise to multiple different roles for SMCs in human and mouse lesions. Potential SMC-specific therapies in atherosclerosis are presented.

Animal model for tendinopathy

Background

Tendinopathy is a common motor system disease that leads to pain and reduced function. Despite its prevalence, our mechanistic understanding is incomplete, leading to limited efficacy of treatment options. Animal models contribute significantly to our understanding of tendinopathy and some therapeutic options. However, the inadequacies of animal models are also evident, largely due to differences in anatomical structure and the complexity of human tendinopathy. Different animal models reproduce different aspects of human tendinopathy and are therefore suitable for different scenarios. This review aims to summarize the existing animal models of tendinopathy and to determine the situations in which each model is appropriate for use, including exploring disease mechanisms and evaluating therapeutic effects.

Methods

We reviewed relevant literature in the PubMed database from January 2000 to December 2022 using the specific terms ((tendinopathy) OR (tendinitis)) AND (model) AND ((mice) OR (rat) OR (rabbit) OR (lapin) OR (dog) OR (canine) OR (sheep) OR (goat) OR (horse) OR (equine) OR (pig) OR (swine) OR (primate)). This review summarized different methods for establishing animal models of tendinopathy and classified them according to the pathogenesis they simulate. We then discussed the advantages and disadvantages of each model, and based on this, identified the situations in which each model was suitable for application.

Results

For studies that aim to study the pathophysiology of tendinopathy, naturally occurring models, treadmill models, subacromial impingement models and metabolic models are ideal. They are closest to the natural process of tendinopathy in humans. For studies that aim to evaluate the efficacy of possible treatments, the selection should be made according to the pathogenesis simulated by the modeling method. Existing tendinopathy models can be classified into six types according to the pathogenesis they simulate: extracellular matrix synthesis-decomposition imbalance, inflammation, oxidative stress, metabolic disorder, traumatism and mechanical load.

Conclusions

The critical factor affecting the translational value of research results is whether the selected model is matched with the research purpose. There is no single optimal model for inducing tendinopathy, and researchers must select the model that is most appropriate for the study they are conducting.

The translational potential of this article

The critical factor affecting the translational value of research results is whether the animal model used is compatible with the research purpose. This paper provides a rationale and practical guide for the establishment and selection of animal models of tendinopathy, which is helpful to improve the clinical transformation ability of existing models and develop new models.

Pyroptosis in cardiovascular diseases: Pumping gasdermin on the fire

Pyroptosis is a form of programmed cell death associated with activation of inflammasomes and inflammatory caspases, proteolytic cleavage of gasdermin proteins (forming pores in the plasma membrane), and selective release of proinflammatory mediators. Induction of pyroptosis results in amplification of inflammation, contributing to the pathogenesis of chronic cardiovascular diseases such as atherosclerosis and diabetic cardiomyopathy, and acute cardiovascular events, such as thrombosis and myocardial infarction. While engagement of pyroptosis during sepsis-induced cardiomyopathy and septic shock is expected and well documented, we are just beginning to understand pyroptosis involvement in the pathogenesis of cardiovascular diseases with less defined inflammatory components, such as atrial fibrillation. Due to the danger that pyroptosis represents to cells within the cardiovascular system and the whole organism, multiple levels of pyroptosis regulation have evolved. Those include regulation of inflammasome priming, post-translational modifications of gasdermins, and cellular mechanisms for pore removal. While pyroptosis in macrophages is well characterized as a dramatic pro-inflammatory process, pyroptosis in other cell types within the cardiovascular system displays variable pathways and consequences. Furthermore, different cells and organs engage in local and distant crosstalk and exchange of pyroptosis triggers (oxidized mitochondrial DNA), mediators (IL-1β, S100A8/A9) and antagonists (IL-9). Development of genetic tools, such as Gasdermin D knockout animals, and small molecule inhibitors of pyroptosis will not only help us fully understand the role of pyroptosis in cardiovascular diseases but may result in novel therapeutic approaches inhibiting inflammation and progression of chronic cardiovascular diseases to reduce morbidity and mortality from acute cardiovascular events.

T Cells in Atherosclerosis: Key Players in the Pathogenesis of Vascular Disease

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of lipid-rich plaques within arterial walls. T cells play a pivotal role in the pathogenesis of atherosclerosis in which they help orchestrate immune responses and contribute to plaque development and instability. Here, we discuss the recognition of atherosclerosis-related antigens that may trigger T cell activation together with additional signaling from co-stimulatory molecules and lesional cytokines. Although few studies have indicated candidates for the antigen specificity of T cells in atherosclerosis, further research is needed. Furthermore, we describe the pro-atherogenic and atheroprotective roles of diverse subsets of T cells such as CD4+ helper, CD8+ cytotoxic, invariant natural killer, and γδ T cells. To classify and quantify T cell subsets in atherosclerosis, we summarize current methods to analyze cellular heterogeneity including single cell RNA sequencing and T cell receptor (TCR) sequencing. Further insights into T cell biology will help shed light on the immunopathology of atherosclerosis, inform potential therapeutic interventions, and pave the way for precision medicine approaches in combating cardiovascular disease.

Computationally Modelling Cholesterol Metabolism and Atherosclerosis

Cardiovascular disease (CVD) is the leading cause of death globally. The underlying pathological driver of CVD is atherosclerosis. The primary risk factor for atherosclerosis is elevated low-density lipoprotein cholesterol (LDL-C). Dysregulation of cholesterol metabolism is synonymous with a rise in LDL-C. Due to the complexity of cholesterol metabolism and atherosclerosis mathematical models are routinely used to explore their non-trivial dynamics. Mathematical modelling has generated a wealth of useful biological insights, which have deepened our understanding of these processes. To date however, no model has been developed which fully captures how whole-body cholesterol metabolism intersects with atherosclerosis. The main reason for this is one of scale. Whole body cholesterol metabolism is defined by macroscale physiological processes, while atherosclerosis operates mainly at a microscale. This work describes how a model of cholesterol metabolism was combined with a model of atherosclerotic plaque formation. This new model is capable of reproducing the output from its parent models. Using the new model, we demonstrate how this system can be utilized to identify interventions that lower LDL-C and abrogate plaque formation.

Lipid-laden foam cells in the pathology of atherosclerosis: shedding light on new therapeutic targets

INTRODUCTION

Lipid-laden foam cells within atherosclerotic plaques are key players in all phases of lesion development including its progression, necrotic core formation, fibrous cap thinning, and eventually plaque rupture. Manipulating foam cell biology is thus an attractive therapeutic strategy at early, middle, and even late stages of atherosclerosis. Traditional therapies have focused on prevention, especially lowering plasma lipid levels. Despite these interventions, atherosclerosis remains a major cause of cardiovascular disease, responsible for the largest numbers of death worldwide.

AREAS COVERED

Foam cells within atherosclerotic plaques are comprised of macrophages, vascular smooth muscle cells, and other cell types which are exposed to high concentrations of lipoproteins accumulating within the subendothelial intimal layer. Macrophage-derived foam cells are particularly well studied and have provided important insights into lipid metabolism and atherogenesis. The contributions of foam cell-based processes are discussed with an emphasis on areas of therapeutic potential and directions for drug development.

EXERT OPINION

As key players in atherosclerosis, foam cells are attractive targets for developing more specific, targeted therapies aimed at resolving atherosclerotic plaques. Recent advances in our understanding of lipid handling within these cells provide insights into how they might be manipulated and clinically translated to better treat atherosclerosis.

Hyperbaric Oxygen Therapy Ameliorates Sperm Parameters in Apolipoprotein E Knockout Mice Testes by Attenuating Oxidative Stress and Inflammation

Apolipoprotein E (ApoE) is a member of apolipoprotein (apo) family and plays critical role in lipid metabolism. In this study, the relationship between abnormal lipid metabolism caused by ApoE-deficient and male reproduction was investigated. The effect of hyperbaric oxygen (HBO) therapy on 7-month-old ApoE-knockout male mice was assessed subsequently. Mice were randomly divided into 3 groups: control group (WT), ApoE (- / -) group (AP-CON), and ApoE (- / -) plus HBO group (AP-HBO), which received HBO treatment. We found that ApoE knockout caused a decrease in male reproductive capacity due to the reduced total sperm motility, progressive motility (PR), and lower blastocyst formation rate. HBO treatment could accelerate serum lipoprotein metabolism including LDL, T-CHO, and TG and semen quality. As a result, fertilization and blastocyst formation of AP-HBO group were higher than that of AP-CON, proving positive therapeutic effect. Mechanism exploration found that HBO treatment ameliorated the testicular microenvironment by attenuating inflammatory factor production and oxidative stress, eventually improved the sperm motility. Collectively, our study provided more evidences of HBO treatment for improving the semen quality of patients with abnormal lipid metabolism caused by ApoE-deficient.

Exercise-induced endothelial Mecp2 lactylation suppresses atherosclerosis via the Ereg/MAPK signalling pathway

BACKGROUND AND AIMS

Lactylation, a recently identified post-translational modification (PTM), plays a central role in the regulation of multiple physiological and pathological processes. Exercise is known to provide protection against cardiovascular disease. However, whether exercise-generated lactate changes lactylation and is involved in the exercise-induced attenuation of atherosclerotic cardiovascular disease (ASCVD) remains unclear. The purpose of this study was to investigate the effects and mechanisms of exercise-induced lactylation on ASCVD.

METHODS AND RESULTS

Using the high-fat diet-induced apolipoprotein-deficient mouse model of ASCVD, we found that exercise training promoted Mecp2 lysine lactylation (Mecp2k271la); it also decreased the expression of vascular cell adhesion molecule 1 (Vcam-1), intercellular adhesion molecule 1 (Icam-1), monocyte chemoattractant protein 1 (Mcp-1), interleukin (IL)-1β, IL-6, and increased the level of endothelial nitric oxide synthase (Enos) in the aortic tissue of mice. To explore the underlying mechanisms, mouse aortic endothelial cells (MAECs) were subjected to RNA-sequencing and CHIP-qPCR, which confirmed that Mecp2k271la repressed the expression of epiregulin (Ereg) by binding to its chromatin, demonstrating Ereg as a key downstream molecule for Mecp2k271la. Furthermore, Ereg altered the mitogen-activated protein kinase (MAPK) signalling pathway through regulating the phosphorylation level of epidermal growth factor receptor, thereby affecting the expression of Vcam-1, Icam-1, Mcp-1, IL-1β, IL-6, and Enos in ECs, which in turn promoted the regression of atherosclerosis. In addition, increasing the level of Mecp2k271la by exogenous lactate administration in vivo also inhibits the expression of Ereg and the MAPK activity in ECs, resulting in repressed atherosclerotic progression.

CONCLUSIONS

In summary, this study provides a mechanistic link between exercise and lactylation modification, offering new insight into the anti-atherosclerotic effects of exercise-induced PTM.

Berberine is a potential alternative for metformin with good regulatory effect on lipids in treating metabolic diseases

Metformin (MTF) and berberine (BBR) share several therapeutic benefits in treating metabolic-related disorders. However, as the two agents have very different chemical structure and bioavailability in oral route, the goal of this study is to learn their characteristics in treating metabolic disorders. The therapeutic efficacy of BBR and MTF was systemically investigated in the high fat diet feeding hamsters and/or ApoE^(-/-) mice; in parallel, gut microbiota related mechanisms were studied for both agents. We discovered that, although both two drugs had almost identical effects on reducing fatty liver, inflammation and atherosclerosis, BBR appeared to be superior over MTF in alleviating hyperlipidemia and obesity, but MTF was more effective than BBR for the control of blood glucose. Association analysis revealed that the modulation of intestinal microenvironment played a crucial role in the pharmacodynamics of both drugs, in which their respective superiority on the regulation of gut microbiota composition and intestinal bile acids might contribute to their own merits on lowering glucose or lipids. This study shows that BBR may be a good alternative for MTF in treating diabetic patients, especially for those complicated with dyslipidemia and obesity.

From worms to humans: Understanding intestinal lipid metabolism via model organisms

The intestine is responsible for efficient absorption and packaging of dietary lipids before they enter the circulatory system. This review provides a comprehensive overview of how intestinal enterocytes from diverse model organisms absorb dietary lipid and subsequently secrete the largest class of lipoproteins (chylomicrons) to meet the unique needs of each animal. We discuss the putative relationship between diet and metabolic disease progression, specifically Type 2 Diabetes Mellitus. Understanding the molecular response of intestinal cells to dietary lipid has the potential to undercover novel therapies to combat metabolic syndrome.

The impact of mild hypercholesterolemia on injury repair in the rat patellar tendon

Hypercholesterolemia is associated with tendon pathology and injury prevalence. Lipids can accumulate in the tendon's extracellular spaces, which may disrupt its hierarchical structure and the tenocytes physicochemical environment. We hypothesized that the tendon's ability to repair after injury would be attenuated with elevated cholesterol levels, leading to inferior mechanical properties. Fifty wild-type (sSD) and 50 apolipoprotein E knock-out rats (ApoE^{-/ -} ) were given a unilateral patellar tendon (PT) injury at 12 weeks old; the uninjured limb served as a control. Animals were euthanized at 3-, 14,- or 42-days postinjury and PT healing was investigated. ApoE^{-/ -} serum cholesterol was double that of SD rats (mean: 2.12 vs. 0.99 mg/mL, p < 0.001) and cholesterol level was related to the expression of several genes after injury; notably rats with higher cholesterol demonstrated a blunted inflammatory response. There was little physical evidence of tendon lipid content or differences in injury repair between groups, therefore we were not surprised that tendon mechanical or material properties did not differ between strains. The young age and the mild phenotype of our ApoE^{-/ -} rats might explain these findings. Hydroxyproline content was positively related to total blood cholesterol, but this result did not translate to observable biomechanical differences, perhaps due to the narrow range of cholesterol levels observed. Tendon inflammatory and healing activity is modulated at the mRNA level even with a mild hypercholesterolemia. These important initial impacts need to be investigated as they may contribute to the known consequences of cholesterol on tendons in humans.

A systematic evidence map for the evaluation of noncancer health effects and exposures to polychlorinated biphenyl mixtures

Assessing health outcomes associated with exposure to polychlorinated biphenyls (PCBs) is important given their persistent and ubiquitous nature. PCBs are classified as a Group 1 carcinogen, but the full range of potential noncancer health effects from exposure to PCBs has not been systematically summarized and evaluated. We used systematic review methods to identify and screen the literature using combined manual review and machine learning approaches. A protocol was developed that describes the literature search strategy and Populations, Exposures, Comparators, and Outcomes (PECO) criteria used to facilitate subsequent screening and categorization of literature into a systematic evidence map of PCB exposure and noncancer health endpoints across 15 organs/systems. A comprehensive literature search yielded 62,599 records. After electronic prioritization steps, 17,037 studies were manually screened at the title and abstract level. An additional 900 studies identified by experts or supplemental searches were also included. After full-text screening of 3889 references, 1586 studies met the PECO criteria. Relevant study details such as the endpoints assessed, exposure duration, and species were extracted into literature summary tables. This review compiles and organizes the human and mammalian studies from these tables into an evidence map for noncancer health endpoints and PCB mixture exposure to identify areas of robust research as well as areas of uncertainty that would benefit from future investigation. Summary data are available online as interactive visuals with downloadable metadata. Sufficient research is available to inform PCB hazard assessments for most organs/systems, but the amount of data to inform associations with specific endpoints differs. Furthermore, despite many years of research, sparse data exist for inhalation and dermal exposures, which are highly relevant human exposure routes. This evidence map provides a foundation for future systematic reviews and noncancer hazard assessments of PCB mixtures and for strategic planning of research to inform areas of greater uncertainty.

Ketosis Prevents Abdominal Aortic Aneurysm Rupture Through CCR2 Downregulation and Enhanced MMP Balance

Abdominal aortic aneurysms (AAAs) are common in aging populations, and AAA rupture is associated with high morbidity and mortality. There is currently no effective medical preventative therapy for AAAs to avoid rupture. It is known that the monocyte chemoattractant protein (MCP-1) / C-C chemokine receptor type 2 (CCR2) axis critically regulates AAA tissue inflammation, matrix-metalloproteinase (MMP) production, and in turn extracellular matrix (ECM) stability. However, therapeutic modulation of the CCR2 axis for AAA disease has so far not been accomplished. Since ketone bodies (KBs) are known to trigger repair mechanisms in response to vascular tissue inflammation, we evaluated whether systemic in vivo ketosis can impact CCR2 signaling, and therefore impact AAA expansion and rupture. To evaluate this, male Sprague-Dawley rats underwent surgical AAA formation using porcine pancreatic elastase (PPE), and received daily β-aminopropionitrile (BAPN) to promote AAA rupture. Animals with formed AAAs received either a standard diet (SD), ketogenic diet (KD), or exogenous KB supplements (EKB). Animals that received KD and EKB reached a state of ketosis, and had significantly reduced AAA expansion and incidence of rupture. Ketosis also led to significantly reduced CCR2, inflammatory cytokine content, and infiltrating macrophages in AAA tissue. Additionally, animals in ketosis had improved balance in aortic wall matrix-metalloproteinase (MMP), reduced extracellular matrix (ECM) degradation, and higher aortic media Collagen content. This study demonstrates that ketosis plays an important therapeutic role in AAA pathobiology, and provides the impetus for future studies investigating the role of ketosis as a preventative strategy for individuals with AAAs.

Brazilian green propolis extracts modulate cholesterol homeostasis in a preclinical guinea pig model: an in vitro and in vivo study

Green propolis produced by Apis melífera bees, having Baccharis dracunculifolia D.C. (Asteraceae) as the primary botanical source, has been used in traditional medicine to treat numerous disorders. However, studies evaluating propolis' potential in treating cardiovascular diseases via its effects on cholesterol metabolism are lacking. Therefore, this study investigated the effects of green propolis extracts on lipid metabolism in hypercholesterolemic guinea pigs. Chemical characterization of ethanolic extracts of green propolis samples was undertaken using HPLC. The in vitro characterization included an evaluation of the antioxidant capacity of the hydroalcoholic extract of green propolis (DPPH and FRAP assays) and its ability to act as an inhibitor of the HMG-CoA reductase enzyme. In vivo, we investigated the effect of the hydroalcoholic extract of green propolis on lipid metabolism in hypercholesterolemic guinea pigs. Results obtained validated previous reports of significant antioxidant activity. HPLC analysis confirmed that coumaric acid, artepillin C, and baccharin were the most common and abundant compounds in green propolis samples among the studied compounds. Furthermore, the compounds in these extracts acted as effective HMG-CoA reductase inhibitors in vitro. In vivo assays demonstrated that a hypercholesterolemic diet significantly reduced serum levels of the HDL cholesterol fraction. Simvastatin and propolis hydroalcoholic extracts promoted a significant increase in HDL cholesterol, suggesting that these extracts can improve the serum lipid profile of hypercholesterolemic guinea pigs. Results obtained in this study provide a perspective on the possible hypocholesterolemic effect of green propolis, suggesting that it can improve the serum lipid profile in hypercholesterolemic guinea pigs.

Single-Cell RNA-Seq Reveals a Population of Smooth Muscle Cells Responsible for Atherogenesis

Understanding the regional propensity differences of atherosclerosis (AS) development is hindered by the lack of animal models suitable for the study of the disease process. In this paper, we used 3S-ASCVD dogs, an ideal large animal human-like models for AS, to interrogate the heterogeneity of AS-prone and AS-resistant arteries; and at the single-cell level, identify the dominant cells involved in AS development. Here we present data from 3S-ASCVD dogs which reliably mimic human AS pathophysiology, predilection for lesion sites, and endpoint events. Our analysis combined bulk RNA-seq with single-cell RNA-seq to depict the transcriptomic profiles and cellular atlas of AS-prone and AS-resistant arteries in 3S-ASCVD dogs. Our results revealed the integral role of smooth muscle cells (SMCs) in regional propensity for AS. Notably, TNC+ SMCs were major contributors to AS development in 3S-ASCVD dogs, indicating enhanced extracellular matrix remodeling and transition to myofibroblasts during the AS process. Moreover, TNC+ SMCs were also present in human AS-prone carotid plaques, suggesting a potential origin of myofibroblasts and supporting the relevance of our findings. Our study provides a promising large animal model for pre-clinical studies of ASCVD and add novel insights surrounding the regional propensity of AS development in humans, which may lead to interventions that delay or prevent lesion progression and adverse clinical events.

Vitamin C Deficiency Exacerbates Dysfunction of Atherosclerotic Coronary Arteries in Guinea Pigs Fed a High-Fat Diet

Vitamin C (vitC) deficiency has been associated with an increased risk of cardiovascular disease; while several putative mechanistic links have been proposed, functional evidence supporting a causal relationship is scarce. In this study, we investigated how vitC deficiency affects coronary artery vasomotor function and the development of coronary atherosclerotic plaques in guinea pigs subjected to chronic dyslipidemia by a high-fat diet regime. Female Hartley guinea pigs were fed either a control (low-fat diet and sufficient vitC) (N = 8) or a high-fat diet with either sufficient (N = 8) or deficient (N = 10) vitC for 32 weeks. Guinea pigs subjected to the high-fat diet developed significant atherosclerotic plaques in their coronary arteries, with no quantitative effect of vitC deficiency. In isolated coronary arteries, vasomotor responses to potassium, carbachol, nitric oxide, or bradykinin were studied in a wire myograph. Carbachol, bradykinin, and nitric oxide mediated relaxation in the coronary arteries of the control group. While vasorelaxation to carbachol and nitric oxide was preserved in the two high-fat diet groups, bradykinin-induced vasorelaxation was abolished. Interestingly, bradykinin induced a significant contraction in coronary arteries from vitC-deficient guinea pigs (p < 0.05). The bradykinin-induced contraction was unaffected by L-NAME but significantly inhibited by both indomethacin and vitC, suggesting that, during vitC deficiency, increased release of arachidonic acid metabolites and vascular oxidative stress are involved in the constrictor effects mediated by bradykinin. In conclusion, the present study shows supporting evidence that poor vitC status negatively affects coronary artery function.

UV-B filter octylmethoxycinnamate-induced vascular endothelial disruption on rat aorta: In silico and in vitro approach

Throughout human life, an extensive and varied range of emerging environmental contaminants, called endocrine disruptors (EDCs), cause adverse health effects, including in the cardiovascular (CV) system. Cardiovascular diseases (CVD) are worryingly one of the leading causes of all mortality and mobility worldwide. The UV-B filter octylmethoxycinnamate (also designated octinoxate, or ethylhexyl methoxycinnamate (CAS number: 5466-77-3)) is an EDC widely present in all personal care products. However, to date, there are no studies evaluating the OMC-induced effects on vasculature using animal models to improve human cardiovascular health. This work analysed the effects of OMC on rat aorta vasculature and explored the modes of action implicated in these effects. Our results indicated that OMC relaxes the rat aorta by endothelium-dependent mechanisms through the signaling pathways of cyclic nucleotides and by endothelium-independent mechanisms involving inhibition of L-Type voltage-operated Ca²⁺ channels (L-Type VOCC). Overall, OMC toxicity on rat aorta may produce hypotension via vasodilation due to excessive NO release and blockade of L-Type VOCC. Moreover, the OMC-induced endothelial dysfunction may also occur by promoting the endothelial release of endothelin-1. Therefore, our findings demonstrate that exposure to OMC alters the reactivity of the rat aorta and highlight that long-term OMC exposure may increase the risk of human CV diseases.

Aucubin administration suppresses STING signaling and mitigated high-fat diet-induced atherosclerosis and steatohepatosis in LDL receptor deficient mice

The rising obesity epidemic in developed countries is associated with many chronic inflammatory diseases including atherosclerosis and nonalcoholic steatohepatitis (NASH). Consuming aucubin may benefit health by suppressing inflammation. Herein, we studied the effects of aucubin consumption on atherosclerosis and NASH progression induced by high-fat diet (HFD) in LDL receptor deficient (LDLr^-/-) mice. Adult LDLr^-/- mice were fed with HFD for 12 weeks and received oral administration of aucubin for the last 6 weeks. Aucubin did not alter body weight or dyslipidemia, but lowered hyperglycemia and mitigated HFD-induced atherosclerosis and hepatic impairments in LDLr^-/- mice. Aucubin administration inhibited HFD-induced inflammation and downregulated mRNA and protein expression of stimulator of IFN genes (STING) in both aortas and livers of LDLr^-/- mice. In vitro, aucubin suppressed mitochondrial DNA (mtDNA)-induced activation of STING/NFκB pathway and downregulated gene expression of pro-inflammatory cytokines in cultured bone marrow-derived macrophages (BMDM). Furthermore, aucubin enhanced microRNA-181a-5p (miR-181a-5p) levels in both aortas and livers of LDLr^-/- mice. Importantly, miR-181a-5p mimicked the inhibitory effect of aucubin on STING/NFκB pathway and inflammation in BMDM. In conclusion, aucubin consumption attenuated HFD-induced atherosclerosis and NASH progression in LDLr^-/- mice, possibly through modulating miR-181a-5p/STING and inhibiting inflammation.

Effect of Recombinant Netrin-1 Protein Combined with Peripheral Blood Mesenchymal Stem Cells on Angiogenesis in Rats with Arteriosclerosis Obliterans

This work was aimed to explore the effect of recombinant netrin-1 protein and peripheral blood mesenchymal stem cells (MSCs) on the angiogenesis ability of atherosclerosis. 28 Sprague Dawley (SD) rats were taken as research models. The arterial occlusion models were created by surgery and then divided into the saline control group (n =7), netrin-1 treatment group (n =7), MSCs treatment group (n =7), and netrin-1 + MSCs combined treatment group (n =7). The peripheral blood MSCs were extracted from the peritoneal cavity of diseased SD rats and cultured alone or in combination with netrin-1. The individually cultured MSCs and netrin-1 were locally injected into the ischemic tissues of SD rats. The Tarlov scoring was performed at the first, second, and third week of treatment, respectively. The expression of vascular endothelial growth factor (VEGF) was also measured by quantitative real-time polymerase chain reaction (qRT-PCR), and the capillary density was measured by immunofluorescence staining. The mean maximum contractility of the gastrocnemius muscle in each group was determined in the third week after treatment. The Tarlov score of the netrin-1 + MSCs group was significantly higher than that of the control group (P < 0.05) at the second week. To the 4th week of treatment, the Tarlov score of the netrin-1 + MSCs group was highly increased compared to the netrin-1 group and the MSCs group (P < 0.05). The expression of VEGF in the treatment groups was greatly increased each week compared to the control group (P < 0.05). Compared with the netrin-1 and the MSCs groups, the VEGF was also notably increased in the netrin-1 + MSCs group (P <0.05). The capillary densities of the treatment groups were observably greater than that of the control group in the second and third weeks (P <0.05), while the capillary density in the netrin-1 + MSCs group was also significantly increased than those in the netrin-1 group and the MSCs group (P < 0.05). The mean maximum contractility of the netrin-1 + MSCs group was remarkably higher than that of the other groups (P < 0.05). The netrin-1 + MSCs group achieved the higher Tarlov score, higher VEGF expression, higher capillary density, and better muscle recovery than netrin-1 and MSCs treatments.

Tackling Atherosclerosis via Selected Nutrition

The development and pathogenesis of atherosclerosis are significantly influenced by lifestyle, particularly nutrition. The modern level of science and technology development promote personalized nutrition as an efficient preventive measure against atherosclerosis. In this survey, the factors were revealed that contribute to the formation of an individual approach to nutrition: genetic characteristics, the state of the microbiota of the gastrointestinal tract (GIT) and environmental factors (diets, bioactive components, cardioprotectors, etc.). In the course of the work, it was found that in order to analyze the predisposition to atherosclerosis associated with nutrition, genetic features affecting the metabolism of nutrients are significant. The genetic features include the presence of single nucleotide polymorphisms (SNP) of genes and epigenetic factors. The influence of telomere length on the pathogenesis of atherosclerosis and circadian rhythms was also considered. Relatively new is the study of the relationship between chrono-nutrition and the development of metabolic diseases. That is, to obtain the relationship between nutrition and atherosclerosis, a large number of genetic markers should be considered. In this relation, the question arises: "How many genetic features need to be analyzed in order to form a personalized diet for the consumer?" Basically, companies engaged in nutrigenetic research and choosing a diet for the prevention of a number of metabolic diseases use SNP analysis of genes that accounts for lipid metabolism, vitamins, the body's antioxidant defense system, taste characteristics, etc. There is no set number of genetic markers. The main diets effective against the development of atherosclerosis were considered, and the most popular were the ketogenic, Mediterranean, and DASH-diets. The advantage of these diets is the content of foods with a low amount of carbohydrates, a high amount of vegetables, fruits and berries, as well as foods rich in antioxidants. However, due to the restrictions associated with climatic, geographical, material features, these diets are not available for a number of consumers. The way out is the use of functional products, dietary supplements. In this approach, the promising biologically active substances (BAS) that exhibit anti-atherosclerotic potential are: baicalin, resveratrol, curcumin, quercetin and other plant metabolites. Among the substances, those of animal origin are popular: squalene, coenzyme Q10, omega-3. For the prevention of atherosclerosis through personalized nutrition, it is necessary to analyze the genetic characteristics (SNP) associated with the metabolism of nutrients, to assess the state of the microbiota of the GIT. Based on the data obtained and food preferences, as well as the individual capabilities of the consumer, the optimal diet can be selected. It is topical to exclude nutrients of which their excess consumption stimulates the occurrence and pathogenesis of atherosclerosis and to enrich the diet with functional foods (FF), BAS containing the necessary anti-atherosclerotic, and stimulating microbiota of the GIT nutrients. Personalized nutrition is a topical preventive measure and there are a number of problems hindering the active use of this approach among consumers. The key factors include weak evidence of the influence of a number of genetic features, the high cost of the approach, and difficulties in the interpretation of the results. Eliminating these deficiencies will contribute to the maintenance of a healthy state of the population through nutrition.

Mechanism of Action of Shenerjiangzhi Formulation on Hyperlipidemia Induced by Consumption of a High-Fat Diet in Rats Using Network Pharmacology and Analyses of the Gut Microbiota

Shenerjiangzhi formulation (SEJZ) is a new traditional Chinese medicine formulation (patent number: CN110680850A). SEJZ contains Eleutherococcus senticosus (Rupr. and Maxim.), Maxim (Araliaceae; E. senticosus radix and rhizome), Lonicera japonica Thunb (Caprifoliaceae; Lonicera japonica branch, stem), Crataegus pinnatifida Bunge (Rosaceae; Crataegus pinnatifida fruit), and Auricularia auricula. SEJZ has been designed to treat hyperlipidemia. Despite the therapeutic benefits of SEJZ, its underlying mechanism of action is not known. We explored the efficacy of SEJZ against hyperlipidemia by integrating network pharmacology and 16S rRNA gene sequencing and elucidated its mechanism of action. First, SEJZ targets were found through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and from the literature. Hyperlipidemia-related therapeutic targets were obtained from GeneCards, Online Mendelian Inheritance in Man, and DrugBank databases. Then, Search Tool for the Retrieval of Interacting Genes/Proteins and Cytoscape were applied for the analyses and construction of a protein–protein interaction (PPI) network. The Kyoto Encyclopedia of Genes and Genomes database was employed to identify signaling pathways that were enriched. Second, the therapeutic effects of SEJZ against hyperlipidemia induced by consumption of a high-fat diet in rats were evaluated by measuring body weight changes and biochemical tests. SEJZ treatment was found to alleviate obesity and hyperlipidemia in rats. Finally, 16S rRNA gene sequencing showed that SEJZ could significantly increase the abundance of short-chain fatty acid-producing bacteria, restore the intestinal barrier, and maintain intestinal-flora homeostasis. Using PICRUSt2, six metabolic pathways were found to be consistent with the results of network pharmacology: “African trypanosomiasis”, “amoebiasis”, “arginine and proline metabolism”, “calcium signaling pathway”, “NOD-like receptor signaling pathway”, and “tryptophan metabolism”. These pathways might represent how SEJZ works against hyperlipidemia. Moreover, the “African trypanosomiasis pathway” had the highest association with core genes. These results aid understanding of how SEJZ works against dyslipidemia and provide a reference for further studies.

In vivo Evidence of Arterial Dynamic Properties Alteration in Atherosclerotic Rabbit

OBJECTIVES

Atherosclerosis severely damages the arterial wall. The aim of this study was to assess in vivo, for the first time, arterial dynamic properties, reactivity, and stiffness in atherosclerotic (ATH) rabbits.

METHODS

The rabbits were fed with 0.3% cholesterol diet. Femoral artery (FA) or abdominal aorta (AA) diameter was recorded by echotracking, together with blood pressure. Arterial reactivity after local administration of agents and stiffness were measured as diameter or pulsatile diameter changes.

RESULTS

FA dilation induced by acetylcholine was reduced in the function of diet duration (9-65 weeks). With mid-term diet duration (35-45 weeks), the dilation to nitroprusside was greatly reduced; the constriction to norepinephrine was reduced but not that to serotonin, thromboxane agonist, or angiotensin II. After 17- and 28-week diet AA and FA stiffness were increased while distensibility was reduced. Arterial stiffness measured by regional pulse wave velocity was unaltered. We observed that after 28-week diet, FA exhibited a stiffened wall at the plaque level and higher distensibility at the upstream site.

DISCUSSION/CONCLUSION

Arterial reactivity and compliance were greatly modified by atherosclerosis, at various degrees dependent on diet duration. ATH rabbit is therefore a suitable model for in vivo investigations of treatments targeting dynamic properties of arterial wall.

CD93 in macrophages: A novel target for atherosclerotic plaque imaging?

Noninvasive imaging atherosclerotic (AS) plaque is of great importance for early diagnosis. Recently, CD93 in MΦ was linked to atherosclerosis development. Herein, we have investigated whether CD93 in MΦ is a potential novel target for atherosclerotic plaque imaging. CD93^hi and CD93^lo MΦ were prepared with or without LPS stimulation, before biological activity was evaluated. A rat AS model was produced with left carotid artery clamped. Whole‐body/ex vivo phosphor autoradiography of the artery and biodistribution were investigated after incorporation of ³H‐2‐DG into CD93^hi and CD93^lo MΦ or after ¹²⁵I‐α‐CD93 (¹²⁵I‐anti‐CD93mAb) injection. The plaque tissue was subjected to CD93/CD68 immunofluorescence/immunohistochemistry staining. CD93^hi and CD93^lo MΦ cells were successfully prepared without significant effect on bioactivity after incorporative labelled with ³H‐2‐DG. The AS model was successfully established. Biodistribution studies showed that adoptive transfer of ³H‐2‐DG‐CD93^hi MΦ or ¹²⁵I‐ α‐CD93 injection resulted in accumulation of radioactivity within the atherosclerotic plaque in the clamped left carotid artery. T/NT (target/non‐target, left/right carotid artery) ratio was higher in the ³H‐2‐DG‐CD93^hi MΦ adoptive transfer group than in the ³H‐2‐DG‐CD93^lo MΦ group (p < .05). Plaque radioactivity in the ¹²⁵I‐α‐CD93 injection group was significantly higher than in the ¹²⁵I‐IgG control group (p < .01). The higher radioactivity accumulated in the clamped left carotid artery was confirmed by phosphor autoradiography. More importantly, CD93/CD68 double‐positive MΦ accumulated at the atherosclerotic plaque in ³H‐2‐DG‐CD93^hi MΦ adoptive transfer group, which correlated with plaque radioactivity (r = .99, p < .01). In summary, both adoptive‐transferred ³H‐2‐DG‐labelled CD93^hi MΦ and ¹²⁵I‐α‐CD93 injection specifically targeted CD93 in atherosclerotic plaque. CD93 is a potential target in atherosclerotic plaque imaging.

Exercise Ameliorates Atherosclerosis via Up-Regulating Serum β-Hydroxybutyrate Levels

Atherosclerosis, accompanied by inflammation and metabolic disorders, is the primary cause of clinical cardiovascular death. In recent years, unhealthy lifestyles (e.g., sedentary lifestyles) have contributed to a worldwide epidemic of atherosclerosis. Exercise is a known treatment of atherosclerosis, but the precise mechanisms are still unknown. Here, we show that 12 weeks of regular exercise training on a treadmill significantly decreased lipid accumulation and foam cell formation in ApoE^−/− mice fed with a Western diet, which plays a critical role in the process of atherosclerosis. This was associated with an increase in β-hydroxybutyric acid (BHB) levels in the serum. We provide evidence that BHB treatment in vivo or in vitro increases the protein levels of cholesterol transporters, including ABCA1, ABCG1, and SR-BI, and is capable of reducing lipid accumulation. It also ameliorated autophagy in macrophages and atherosclerosis plaques, which play an important role in the step of cholesterol efflux. Altogether, an increase in serum BHB levels after regular exercise is an important mechanism of exercise inhibiting the development of atherosclerosis. This provides a novel treatment for atherosclerotic patients who are unable to undertake regular exercise for whatever reason. They will gain a benefit from receiving additional BHB.