Animal models of atherosclerosis

Coronary microvascular dysfunction and myocardial area at risk assessed by cadmium zinc telluride single photon emission computed tomography after primary percutaneous coronary intervention in acute myocardial infarction patients

Background

A high proportion of coronary microvascular dysfunction (CMD) has been observed in patients with acute myocardial infarction (AMI) who have received primary percutaneous coronary intervention (PCI), which may affect their prognosis. This study used cadmium zinc telluride (CZT) single photon emission computed tomography (SPECT) to evaluate the prevalence and characteristics of CMD and myocardial area at risk (AAR) in AMI patients who had undergone primary PCI.

Methods

We conducted a single-center cross-sectional retrospective study at TEDA International Cardiovascular Hospital from September 2021 to June 2022. A total of 83 patients received primary PCI for AMI. Subsequently, a rest/stress dynamic and routine gated myocardial perfusion imaging (MPI) were performed 1 week after PCI. The CMD group was defined as having a residual stenosis of infarct-related artery (IRA) <50% and myocardial flow reserve (MFR) <2.0 in this corresponding territory, whereas MFR ≥2.0 of IRA pertained to the normal control group. Rest-AAR of infarction (%) and stress-AAR (%) were expressed by the percentage of measured rest-defect-size and stress-defect-size in the left ventricular area, respectively. Logistic regression analyses were performed to identify significant predictors of CMD.

Results

A total of 53 patients with a mean age of 57.06±11.99 years were recruited, of whom 81.1% were ST-segment elevation myocardial infarction (STEMI). The proportion of patients with CMD was 79.2% (42/53). The time of pain to SPECT imaging was 7.50±1.27 days in the CMD group and 7.45±1.86 days among controls. CMD patients had a higher body mass index (BMI) than controls (26.48±3.26 vs. 24.36±2.73 kg/m2, P=0.053), and a higher proportion of STEMI, thrombolysis in myocardial infarction (TIMI) 0 grade of IRA prior PCI than controls (88.1% vs. 54.5%, P=0.011; 61.9% vs. 18.2%, P=0.004, respectively). No significant difference was identified in the rest-myocardial blood flow (MBF) of IRA between the 2 groups, whereas the stress-MBF and MFR of IRA, rest-AAR, and stress-AAR in the CMD group were remarkably lowered. Higher BMI [odds ratio (OR): 1.332, 95% confidence interval (CI): 1.008-1.760, P=0.044] and stress-AAR (OR: 1.994, 95% CI: 1.122-3.543, P=0.019) were used as independent predictors of CMD occurrence.

Conclusions

The prevalence of CMD is high in AMI patients who received primary PCI. Each 1 kg/m2 increase in BMI was associated with a 1.3-fold increase in CMD risk. A 5% increase in stress-AAR was associated with a nearly 2-fold increase in CMD risk. Increased BMI and stress-AAR predicts decreased coronary reserve function.

Association of inflammatory markers based on routine blood with prognosis in patients underwent percutaneous coronary intervention

Inflammation contributes to the pathophysiological processes of coronary artery disease. We evaluated the association between inflammatory biomarkers, neutrophil-to-lymphocyte ratio (NLR), red cell distribution width (RDW), systemic inflammatory index, platelet-lymphocyte ratio, and 1-year all-cause mortality in patients underwent percutaneous coronary intervention (PCI). In this retrospective cohort, we consecutively enrolled 4651 patients who underwent PCI. Baseline demographic details, clinical data, and laboratory parameters on admission were analyzed. The primary outcome was 1-year all-cause mortality after PCI. We performed Cox regression and restricted cubic spline analysis to assessed the association between the inflammatory biomarkers and the clinical outcome. The area under the curve from receiver operating characteristic analysis was determined for the ability to classify mortality outcomes. A total of 4651 patients were included. Of these, 198 (4.26%) died on follow-up. Univariate Cox regression showed that NLR (heart rate [HR]: 1.070, 95% confidence interval [CI]: 1.060-1.082, P < .001), RDW (HR: 1.441, 95% CI 1.368-1.518, P < .001), systemic inflammatory index (HR: 1.000, 95% CI 1.000-3.180, P < .001), platelet-lymphocyte ratio (HR: 3.812, 95% CI 1.901-3.364, P < .001) were significant predictors of 1-year all-cause mortality. After adjusting for other confounders in multivariate analysis, NLR (HR: 01.038, 95% CI 1.022-1.054, P < .001) and RDW (HR: 1.437, 95% CI 1.346-1.535, P < .001) remained significant predictors. Restricted cubic spline analysis showed the relationship between RDW, NLR, and 1-year all-cause mortality was linear after adjusting for the covariables (P for non-linearity < 0.001). The multivariable adjusted model led to improvement in the area under the curve to 0.83 (P < .05). Nomogram was created to predict the probability of 1 year mortality. Among the laboratory indices, RDW and NLR showed the best performance for mortality risk prediction. Multivariate predictive models significantly improved risk stratification.

Preclinical models of atherosclerosis: An overview

Atherosclerosis is a primary cause of illness and death globally and its mechanism is still unclear. Different animal models have been created to evaluate the progression of atherosclerosis, allowing researchers to carefully control the circumstances of the experiment as well as the nutrition and environmental risk factors. To investigate the negative effects of various interventions, pathophysiological alterations might be generated utilizing genetic or pharmacological methods. These models' molecular and pathophysiological mechanisms have been clarified through experiments, and they have served as platforms for the creation of new drugs. Different models can be employed to address various research problems, each with its own benefits and drawbacks. In the current review study, various species of atherosclerosis models are discussed, along with the viability of using them in experiments.

PAC1 deficiency reduces chondrogenesis in atherosclerotic lesions of hypercholesterolemic ApoE-deficient mice

BACKGROUND

Induction of chondrogenesis is associated with progressive atherosclerosis. Deficiency of the ADCYAP1 gene encoding pituitary adenylate cyclase-activating peptide (PACAP) aggravates atherosclerosis in ApoE deficient (ApoE-/-) mice. PACAP signaling regulates chondrogenesis and osteogenesis during cartilage and bone development. Therefore, this study aimed to decipher whether PACAP signaling is related to atherogenesis-related chondrogenesis in the ApoE-/- mouse model of atherosclerosis and under the influence of a high-fat diet.

METHODS

For this purpose, PACAP-/-/ApoE-/-, PAC1-/-/ApoE-/-, and ApoE-/- mice, as well as wildtype (WT) mice, were studied under standard chow (SC) or cholesterol-enriched diet (CED) for 20 weeks. The amount of cartilage matrix in atherosclerotic lesions of the brachiocephalic trunk (BT) with maximal lumen stenosis was monitored by alcian blue and collagen II staining on deparaffinized cross sections. The chondrogenic RUNX family transcription factor 2 (RUNX2), macrophages [(MΦ), Iba1+], and smooth muscle cells (SMC, sm-α-actin) were immunohistochemically analyzed and quantified.

RESULTS

ApoE-/- mice fed either SC or CED revealed an increase of alcian blue-positive areas within the media compared to WT mice. PAC1-/-/ApoE-/- mice under CED showed a reduction in the alcian blue-positive plaque area in the BT compared to ApoE-/- mice. In contrast, PACAP deficiency in ApoE-/- mice did not affect the chondrogenic signature under either diet.

CONCLUSIONS

Our data show that PAC1 deficiency reduces chondrogenesis in atherosclerotic plaques exclusively under conditions of CED-induced hypercholesterolemia. We conclude that CED-related chondrogenesis occurs in atherosclerotic plaques via transdifferentiation of SMCs and MΦ, partly depending on PACAP signaling through PAC1. Thus, PAC1 antagonists or PACAP agonists may offer therapeutic potential against pathological chondrogenesis in atherosclerotic lesions generated under hypercholesterolemic conditions, especially in familial hypercholesterolemia. This discovery opens therapeutic perspectives to be used in the treatment against the progression of atherosclerosis.

Blocking cholesterol formation and turnover improves cellular and mitochondria function in murine heart microvascular endothelial cells and cardiomyocytes

Background: Statins and proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) are cornerstones of therapy to prevent cardiovascular disease, acting by lowering lipid concentrations and only partially identified pleiotropic effects. This study aimed to analyze impacts of atorvastatin and synthetic peptide PCSK9i on bioenergetics and function of microvascular endothelial cells and cardiomyocytes. Methods: Mitochondrial function and abundance as well as intracellular nucleotides, membrane potential, cytoskeleton structure, and cell proliferation rate were evaluated in mouse heart microvascular endothelial cells (H5V) and cardiomyocytes (HL-1) under normal and hypoxia-mimicking conditions (CoCl2 exposure). Results: In normal conditions PCSK9i, unlike atorvastatin, enhanced mitochondrial respiratory parameters, increased nucleotide levels, prevented actin cytoskeleton disturbances and stimulated endothelial cell proliferation. Under hypoxia-mimicking conditions both atorvastatin and PCSK9i improved the mitochondrial respiration and membrane potential in both cell types. Conclusion: This study demonstrated that both treatments benefited the endothelial cell and cardiomyocyte bioenergetics, but the effects of PCSK9i were superior.

3D-printed tortuous vessels with Photodissociable and morphology-controllable ink

Acute ischemic stroke (AIS) is a high mortality cerebrovascular disease associated with vessel curvature. However, the relevant mechanism remains unclear due to a lack of appropriate tortuous vascular models to investigate and validate. This study explores the combination of projection-based 3D bioprinting (PBP) with photo-stimulus-responsive techniques to fabricate a sodium alginate (SA)/acrylamide (AAM) hydrogel vascular scaffold capable of bending deformation. The coordination of Fe³⁺ ions with carboxylate groups in the alginate chains of the vascular scaffold acts as a molecular switch, which can be dissociated through photoreduction to enable the deformation response. Fourier Transform Infrared (FTIR) and X-ray Photoelectron Spectroscopy (XPS) results verified the deformation principle. By subjecting the scaffold to UV light exposure, Fe³⁺ is reduced to Fe²⁺ in spatially selected regions, resulting in the release of strain and subsequent deformation. Furthermore, it also controlled the degree and direction of curvature of the vessels. The cell seeding experiment verified that the vascular scaffold showed excellent biocompatibility. Overall, our approach could be used to generate an in vitro model of curved vascular pathology to investigate the pathogenesis and provide new directions for the diagnosis and treatment of vascular diseases in the future.

Long-term atherosclerotic cardiovascular disease risk in patients with cancer: a population-based study

BACKGROUND

The long-term risk of incident atherosclerotic cardiovascular diseases (ASCVD) among cancer patients remains incompletely defined. This study aimed to evaluate the long-term ASCVD risk in cancer patients compared with the non-cancer population.

METHODS

This was a prospective population-based study using data from the Kailuan cohort, 6,204 individuals with newly diagnosed cancer, free of ASCVD, were matched in a 1:1 ratio to non-cancer controls for age (±1) and sex, from June 2006 to December 2020. Multivariable competing risk analyses were performed to evaluate the association between cancer diagnosis and risk of incident ASCVD events (including myocardial infarction, ischemic stroke, heart failure, and revascularization with coronary artery bypass graft surgery or percutaneous coronary intervention).

RESULTS

During a median follow-up of 5.3 (1.7, 9.7) years, 1,019 incident ASCVD events were observed. Compared to participants without cancer, there was a similar risk for incident ASCVD events among cancer patients within the first few years after cancer diagnosis, and the risk declined over time. Overall, cancer patients showed lower risks of incident ASCVD compared to the non-cancer patients over the long term, with a hazard ratio (95% confidence interval) of 0.52 (0.45-0.60) for composite ASCVD events, 0.43 (0.35-0.53) for ischemic stroke, 0.63 (0.42-0.95) for myocardial infarction, 0.63 (0.48-0.83) for heart failure, and 0.82 (0.60-1.11) for coronary revascularization. Baseline level of low-density lipoprotein cholesterol, fasting blood glucose, blood pressure, and high-sensitivity C-reactive protein could independently predict the incident ASCVD among the study population. Subgroup analyses according to cancer types revealed a significantly lower risk of ASCVD events among patients with digestive cancer or respiratory cancer compared with non-cancer controls, but not for urologic or genital cancer. Multiple sensitivity analyses yielded similar results to the primary analysis.

CONCLUSIONS

Long-term ASCVD risk among cancer survivors is not increased compared with the non-cancer individuals, probably driven by a favorable profile of baseline risk factor in cancer population.

Association Between Atherosclerosis-Related Cardiovascular Disease and Uveitis: A Systematic Review and Meta-Analysis

BACKGROUND

Uveitis is not only an intraocular inflammatory disease, but also an indicator of systemic inflammation. It is unclear whether uveitis can increase the risk of cardiovascular disease (CVD) through the atherosclerotic pathway.

METHODS

PubMed and Embase databases were searched until 5 September, 2022. Original studies investigating uveitis and cardiovascular events were selected. The random-effects model was used to calculate the difference of groups in pooled estimates.

RESULTS

A total of six observational studies that included mainly ankylosing spondylitis (AS) patients were included. Of these, three studies reported data on carotid plaques and carotid intima-media thickness (cIMT) and the other three studies provided data on atherosclerosis-related CVD. No significant difference was found in cIMT between uveitis and controls (MD = 0.01, 95% CI = -0.03-0.04, p = 0.66), consistent with the findings of carotid plaque incidence (OR = 1.30, 95% CI = 0.71-2.41, p = 0.39). However, uveitis was associated with a 1.49-fold increase in atherosclerosis-related CVD (HR = 1.49, 95% CI = 1.20-1.84, p = 0.0002).

CONCLUSIONS

Uveitis is a predictor of atherosclerosis-related CVD in AS patients. For autoimmune disease patients with uveitis, earlier screening of cardiovascular risk factors and the implementation of corresponding prevention strategies may be associated with a better prognosis.

Animal models and animal-free innovations for cardiovascular research: current status and routes to be explored. Consensus document of the ESC Working Group on Myocardial Function and the ESC Working Group on Cellular Biology of the Heart

Cardiovascular diseases represent a major cause of morbidity and mortality, necessitating research to improve diagnostics, and to discover and test novel preventive and curative therapies, all of which warrant experimental models that recapitulate human disease. The translation of basic science results to clinical practice is a challenging task, in particular for complex conditions such as cardiovascular diseases, which often result from multiple risk factors and comorbidities. This difficulty might lead some individuals to question the value of animal research, citing the translational 'valley of death', which largely reflects the fact that studies in rodents are difficult to translate to humans. This is also influenced by the fact that new, human-derived in vitro models can recapitulate aspects of disease processes. However, it would be a mistake to think that animal models do not represent a vital step in the translational pathway as they do provide important pathophysiological insights into disease mechanisms particularly on an organ and systemic level. While stem cell-derived human models have the potential to become key in testing toxicity and effectiveness of new drugs, we need to be realistic, and carefully validate all new human-like disease models. In this position paper, we highlight recent advances in trying to reduce the number of animals for cardiovascular research ranging from stem cell-derived models to in situ modelling of heart properties, bioinformatic models based on large datasets, and state-of-the-art animal models, which show clinically relevant characteristics observed in patients with a cardiovascular disease. We aim to provide a guide to help researchers in their experimental design to translate bench findings to clinical routine taking the replacement, reduction, and refinement (3R) as a guiding concept.

Effects of atherogenic diet supplemented with fermentable carbohydrates on metabolic responses and plaque formation in coronary arteries using a Saddleback pig model

Fermentable carbohydrates are gaining interest in the field of human nutrition because of their benefits in obesity-related comorbidities. The aim of this study was to investigate the influence of fermentable carbohydrates, such as pectin and inulin, in an atherogenic diet on metabolic responses and plaque formation in coronary arteries using a Saddleback pig model. Forty-eight healthy pigs aged five months were divided into four feeding groups (n = 10) and one baseline group (n = 8). Three feeding groups received an atherogenic diet (38% crisps, 10% palm fat, and 2% sugar with or without supplementation of 5% pectin or inulin), and one group received a conventional diet over 15 weeks. Feed intake, weight gain, body condition score, and back fat thickness were monitored regularly. Blood and fecal samples were collected monthly to assess the metabolites associated with high cardiovascular risk and fat content, respectively. At the end of 15 weeks, the coronary arteries of the pigs were analyzed for atherosclerotic plaque formation. Independent of supplementation, significant changes were observed in lipid metabolism, such as an increase in triglycerides, bile acids, and cholesterol in serum, in all groups fed atherogenic diets in comparison to the conventional group. Serum metabolome analysis showed differentiation of the feeding groups by diet (atherogenic versus conventional diet) but not by supplementation with pectin or inulin. Cardiovascular lesions were found in all feeding groups and in the baseline group. Supplementation of pectin or inulin in the atherogenic diet had no significant impact on cardiovascular lesion size. Saddleback pigs can develop naturally occurring plaques in coronary arteries. Therefore, this pig model offers potential for further research on the effects of dietary intervention on obesity-related comorbidities, such as cardiovascular lesions, in humans.

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.

Endothelial-Derived APT1-Mediated Macrophage-Endothelial Cell Interactions Participate in the Development of Atherosclerosis by Regulating the Ras/MAPK Signaling Pathway

Acyl-protein thioesterase 1 (APT1) can affect H-Ras localization and function by promoting its depalmitoylation. However, relatively little attention has been paid to the effects of APT1 on H-Ras in the cardiovascular system. In this study, we revealed its roles in atherosclerosis development using oxidative low-density lipoprotein (ox-LDL)-induced endothelial dysfunction models and a Western diet-induced ApoE−/− mouse model. The results showed that APT1 expression was up-regulated, while that of miR-138-5p (miR-138) was down-regulated (p < 0.05) in this model. In the meantime, APT1 and H-Ras were translocated from the cytoplasm to the plasma membrane. Bioinformatic analysis and double fluorescence identified miR-138 as the upstream regulator of APT1. APT1 knockdown regulated H-Ras localization and expression, which subsequently affected the MAPK signaling pathway and the expression of its downstream factors. Further research indicated that human umbilical vein endothelial cells (HUVECs)-derived biogenic nanoparticles (BiNPs), hBPs secretion, and RNA expression of hBP-loaded APT1 were increased (p < 0.05) in the ox-LDL induced endothelial dysfunction model. Meanwhile, the HUVECs-derived APT1 could further affect macrophage function through hBP transportation. Altogether, this study demonstrated that the miR-138-APT1 axis may be partially responsible for atherosclerosis development by regulating the H-Ras-MAPK signaling pathway and hBP transportation. The results also shed novel insight on the underlying mechanisms of, and identify potential diagnostic and therapeutic targets for, atherosclerotic cardiovascular diseases in the future.

Survey of Approaches for Investigation of Atherosclerosis In Vivo

Although in vitro model systems are useful for investigation of atherosclerosis-associated processes, they represent simplification of complex events that occur in vivo, which involve interactions between many different cell types together with their environment. The use of animal model systems is important for more in-depth insights of the molecular mechanisms underlying atherosclerosis and for identifying potential targets for agents that can prevent plaque formation and even reverse existing disease. This chapter will provide a survey of such animal models and associated techniques that are routinely used for research of atherosclerosis in vivo.

MiR-340 Promotes the Proliferation of Vascular Smooth Muscle Cells by Targeting von Hippel-Lindau Tumor Suppressor Gene

ABSTRACT

MiRNAs play key roles in the proliferation of vascular smooth muscle cells (VSMCs). However, the roles and underlying mechanism of miRNAs in VSMCs are not fully understood. The aim of this study was to evaluate the role of miR-340 in the proliferation of VSMCs. The expression levels of miR-340 and von Hippel-Lindau tumor suppressor (VHL) in VSMCs induced by platelet-derived growth factor-BB or fetal bovine serum were measured by q-polymerase chain reaction. The effects of miR-340 and VHL on cell proliferation and invasion were evaluated by CCK-8 assay. Target gene prediction and screening as well as luciferase reporter assay were performed to verify the downstream target genes of miR-340. Western blotting was used to detect the protein expression levels of vascular endothelial growth factor and VHL. Our results showed that the miR-340 was upregulated in platelet-derived growth factor-BBor fetal bovine serum-induced VSMCs. In addition, overexpression of miR-340 promoted VSMCs proliferation and invasion. Moreover, VHL was found to be a potential target for miR-340 and upregulation of VHL-inhibited VSMCs proliferation. MiR-340 plays a critical role in VSMC proliferation and neointimal hyperplasia in rats' carotid balloon injury model. Reduced expression levels of miR-340 promoted VHL-inhibited VSMCs proliferation. In conclusion, miR-340 may play a role in the regulation of proliferation of VSMCs by inhibition of VHL.

Changes of Hematological and Hemorheological Parameters in Rabbits with Hypercholesterolemia

Hypercholesterolemia plays an important role in the development of atherosclerosis, leading to endothelial dysfunction, ischemic events, and increased mortality. Numerous studies suggest the pivotal role of rheological factors in the pathology of atherosclerosis. To get a more detailed hematological and hemorheological profile in hypercholesterolemia, we carried out an experiment on rabbits. Animals were divided into two groups: the control group (Control) was kept on normal rabbit chow, the high-cholesterol diet group (HC) was fed with special increased cholesterol-containing food. Hematological parameters (Sysmex K-4500 automate), whole blood and plasma viscosity (Hevimet-40 capillary viscometer), red blood cell (RBC) aggregation (Myrenne MA-1 aggregometer), deformability and mechanical stability (LoRRca MaxSis Osmoscan ektacytometer) were tested. The white blood cell and platelet count, mean corpuscular volume, and mean corpuscular hemoglobin were significantly higher in the HC group, while the RBC count, hemoglobin, and hematocrit values were lower than the Control data. Viscosity values corrected to 40% hematocrit were higher in the HC group. The RBC aggregation significantly increased in the HC vs. the Control. The HC group showed significantly worse results both in RBCs' deformability and membrane stability. In conclusion, the atherogenic diet worsens the hematological and macro- and micro-rheological parameters, affecting blood flow properties and microcirculation.

Recent Application of Zebrafish Models in Atherosclerosis Research

Atherosclerotic cardiovascular disease is one of the leading causes of death worldwide. Establishing animal models of atherosclerosis is of great benefit for studying its complicated pathogenesis and screening and evaluating related drugs. Although researchers have generated a variety of models for atherosclerosis study in rabbits, mice and rats, the limitations of these models make it difficult to monitor the development of atherosclerosis, and these models are unsuitable for large scale screening of potential therapeutic targets. On the contrast, zebrafish can fulfill these purposes thanks to their fecundity, rapid development ex utero, embryonic transparency, and conserved lipid metabolism process. Thus, zebrafish have become a popular alternative animal model for atherosclerosis research. In this mini review, we summarize different zebrafish models used to study atherosclerosis, focusing on the latest applications of these models to the dynamic monitoring of atherosclerosis progression, mechanistic study of therapeutic intervention and drug screening, and assessment of the impacts of other risk factors.

Clinical Application of Melatonin in the Treatment of Cardiovascular Diseases: Current Evidence and New Insights into the Cardioprotective and Cardiotherapeutic Properties

Cardiovascular diseases (CVDs) are the leading global cause of mortality and disability, tending to happen in younger individuals in developed countries. Despite improvements in medical treatments, the therapy and long-term prognosis of CVDs such as myocardial ischemia-reperfusion, atherosclerosis, heart failure, cardiac hypertrophy and remodeling, cardiomyopathy, coronary artery disease, myocardial infarction, and other CVDs threatening human life are not satisfactory enough. Therefore, many researchers are attempting to identify novel potential therapeutic methods for the treatment of CVDs. Melatonin is an anti-inflammatory and antioxidant agent with a wide range of therapeutic properties. Recently, several investigations have been carried out to evaluate its effectiveness and efficiency in CVDs therapy, focusing on mechanistic pathways. Herein, this review aims to summarize current findings of melatonin treatment for CVDs.

Circular RNA ciRS-7 promotes tube formation in microvascular endothelial cells through downregulation of miR-26a-5p

Atherosclerosis is one of the most common and crucial heart diseases involving the heart and brain. At present, atherosclerosis and its major complications comprise the leading causes of death worldwide. Our purpose was to identify the role of ciRS-7 in atherosclerosis. Tubulogenesis of HMEC-1 cell was evaluated utilizing tube formation assay. Cell Counting Kit-8 assay and flow cytometry were utilized to test viability and apoptosis. Migration assay was utilized to determine the migration capacity of experimental cells. Western blot was applied to examine apoptosis and tube formation-associated protein expression. In addition, the above experiments were repeated when silencing ciRS-7, overexpressing ciRS-7, and upregulating miR-26a-5p. HMEC-1 cells formed tube-like structures over time. Silencing ciRS-7 suppressed viability, migration, and tube formation but promoted apoptosis. Oppositely, overexpressing ciRS-7 reversed the effect in HMEC-1 cells. miR-26a-5p expression was elevated by silencing ciRS-7 and reduced by overexpressing ciRS-7. Moreover, overexpressing ciRS-7 facilitated viability, migration, and tube formation via upregulating miR-26a-5p. Conclusively, overexpressing ciRS-7 mobilized phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway and suppressed c-Jun N-terminal kinase (JNK)/p38 pathway. ciRS-7 exerted influence on apoptosis, viability, migration, and tube formation through mediating PI3K/AKT and JNK/p38 pathways by miR-26a-5p downregulation in HMEC-1 cells.

Dietary cholesterol does not break your heart but kills your liver

It is increasingly accepted that dietary cholesterol has a much lower impact on the progression of cardiovascular disease than previously assumed. However, both animal experiments and human studies seem to support the view that dietary cholesterol may contribute to the transition from benign steatosis to the potentially fatal non-alcoholic steatohepatitis. Cholesterol esters and cholesterol accumulate in the hepatocyte and impair its function. This leads to oxidative stress and endoplasmic reticulum stress triggering the release of pro-inflammatory cytokines and rendering the hepatocyte more susceptible to apoptotic or necrotic cell death. Kupffer cells group around dying hepatocytes and phagocytose the hepatocyte debris and lipids. In addition, they are exposed to lipid peroxidation products released from hepatocytes. Kupffer cells, thus activated, release pro-inflammatory, chemotactic and profibrotic cytokines that promote inflammation and fibrosis. Therefore, dietary cholesterol may be harmful to the liver, in particular when administered in combination with polyunsaturated fatty acids that favor lipid peroxidation.

Delivery of magnetic micro/nanoparticles and magnetic-based drug/cargo into arterial flow for targeted therapy

Magnetic drug targeting (MDT) and magnetic-based drug/cargo delivery are emerging treatment methods which attracting the attention of many researchers for curing different cancers and artery diseases such as atherosclerosis. Herein, computational studies are accomplished by utilizing magnetic approaches for cancer and artery atherosclerosis drug delivery, including nanomagnetic drug delivery and magnetic-based drug/cargo delivery. For the first time, the four-layer structural model of the artery tissue and its porosity parameters are modeled in this study which enables the interaction of particles with the tissue walls in blood flow. The effects of parameters, including magnetic field strength (MFS), magnet size, particle size, the initial position of particles, and the relative magnetic permeability of particles, on the efficacy of MDT through the artery walls are characterized. The magnetic particle penetration into artery layers and fibrous cap (the covering layer over the inflamed part of the artery) is further simulated. The MDT in healthy and diseased arteries demonstrates that some of the particles stuck in these tissues due to the collision of particles or blood flow deviation in the vicinity of the inflamed part of the artery. Therefore the geometry of artery and porosity of its layers should be considered to show the real interaction of particles with the artery walls. Also, the results show that increasing the particles/drug/cargo size and MFS leads to more particles/drug/cargo retention within the tissue. The present work provides insights into the decisive factors in arterial MDT with an obvious impact on locoregional cancer treatment, tissue engineering, and regenerative medicine.

The immune functions of PCSK9: Local and systemic perspectives

Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to low-density lipoprotein receptor (LDLR) to trigger endocytosis and lysosome degradation in hepatocytes, regulating intracellular and plasma cholesterol levels. The discovery of PCSK9 has provided a new target for the management of hypercholesterolemia and cardiovascular risk reduction. There is emerging evidence that shows that PCSK9 may influence the activity of various cell types through either LDLR-dependent or LDLR-independent mechanisms. Changes in the circulating PCSK9 levels have been observed during infection and proinflammatory conditions. Furthermore, PCSK9 as a secreted protein has both local and systemic effects on cellular function. In this review, we summarize the roles of PCSK9 in inflammation.

Mechanisms of Intravascular Linear Ablation Induced Restenosis in Rabbit Abdominal Aorta

Objectives

Percutaneous coronary intervention (PCI) is the mainstay treatment for coronary artery disease but complications such as in-stent restenosis and thrombosis remain problematic. Radiofrequency balloon angioplasty (RBA) can improve lumen dimension, fusing intimal tears, and artery dissection but is associated with higher restenosis rate.

Methods

After establishing an atherosclerosis model based on endothelial abrasion and high cholesterol diet, forty-five rabbits were randomly divided into three groups: RBA (n=20), percutaneous transluminal angioplasty (PTA) (n=20), and control groups (n=5). The RBA and PTA groups were subdivided according to harvested time posttreatment, respectively (1 hour, 7 days, 14 days, and 28 days). Aorta segments were then isolated for hematoxylin and eosin staining, Masson trichrome staining, immunohistochemistry, and Western blot for TLR-4, NF-κB, MCP-1, and VCAM-1expression.

Results

At 28 days, intimal area was significantly lower in the RBA group compared to the PTA and control groups, whilst luminal and medial area were comparable in the RBA and PTA group but higher and lower than the control group, respectively. Expression of TLR-4, NF-κB, MCP-1, and VCAM-1 showed no significant difference between RBA and PTA groups.

Conclusions

RBA can depress the intimal hyperplasia and promote dilatation of the artery to greater extents than PTA at 28 days. However, this did not involve TLR-4 signaling pathway, which likely plays a negligible role in mediating restenosis. Reduction of intimal hyperplasia may be due to injury of ablation to the tunica media and inhibition of VSMC proliferation and migration.

LncRNA DIGIT Accelerates Tube Formation of Vascular Endothelial Cells by Sponging miR-134

Atherosclerosis is one of the most prevalent and important cardiac diseases, involving the heart and brain. This study aimed to explore the impacts of lncRNA Divergent to GSC induced by TGF-b family signaling (DIGIT) on vascular endothelial cells tube-formation capacity so as to reveal the potentials of DIGIT in atherosclerosis therapy. DIGIT expression in human microvascular endothelial HMEC-1 cells was silenced by transfection with shRNAs-targeted DIGIT. The effects of DIGIT silence on cell viability, migration, apoptosis, and tube formation were then assessed. Additionally, the cross-regulation between DIGIT and miR-134, and between miR-134 and Bmi-1 was detected to further reveal through which mechanism (s) DIGIT mediated HMEC-1 cells. The results showed that DIGIT silence significantly reduced cell viability, migration, tube-like structures formation, and induced apoptosis in HMEC-1 cells. DIGIT worked as a sponge for miR-134, and the anti-growth, anti-migratory, and anti-tube-formation functions of DIGIT silence on HMEC-1 cells were abolished by miR-134 suppression. Bmi-1 was a target of miR-134, and Bmi-1 upregulation abolished miR-134 overexpression-diminished cell growth, migration, and tube formation of HMEC-1 cells. Furthermore, Bmi-1 upregulation activated PI3K/AKT and Notch signaling pathways. In conclusion, our study demonstrated that lncRNA DIGIT accelerated tube formation of vascular endothelial cells through sponging miR-134. Our findings suggest that DIGIT and miR-134 may be promising molecular targets for atherosclerosis therapy.

Soybean Oil-Derived Poly-Unsaturated Fatty Acids Enhance Liver Damage in NAFLD Induced by Dietary Cholesterol

While the impact of dietary cholesterol on the progression of atherosclerosis has probably been overestimated, increasing evidence suggests that dietary cholesterol might favor the transition from blunt steatosis to non-alcoholic steatohepatitis (NASH), especially in combination with high fat diets. It is poorly understood how cholesterol alone or in combination with other dietary lipid components contributes to the development of lipotoxicity. The current study demonstrated that liver damage caused by dietary cholesterol in mice was strongly enhanced by a high fat diet containing soybean oil-derived ω6-poly-unsaturated fatty acids (ω6-PUFA), but not by a lard-based high fat diet containing mainly saturated fatty acids. In contrast to the lard-based diet the soybean oil-based diet augmented cholesterol accumulation in hepatocytes, presumably by impairing cholesterol-eliminating pathways. The soybean oil-based diet enhanced cholesterol-induced mitochondrial damage and amplified the ensuing oxidative stress, probably by peroxidation of poly-unsaturated fatty acids. This resulted in hepatocyte death, recruitment of inflammatory cells, and fibrosis, and caused a transition from steatosis to NASH, doubling the NASH activity score. Thus, the recommendation to reduce cholesterol intake, in particular in diets rich in ω6-PUFA, although not necessary to reduce the risk of atherosclerosis, might be sensible for patients suffering from non-alcoholic fatty liver disease.

Smooth muscle cell-driven vascular diseases and molecular mechanisms of VSMC plasticity

Vascular smooth muscle cells (VSMCs) are the major cell type in blood vessels. Unlike many other mature cell types in the adult body, VSMC do not terminally differentiate but retain a remarkable plasticity. Fully differentiated medial VSMCs of mature vessels maintain quiescence and express a range of genes and proteins important for contraction/dilation, which allows them to control systemic and local pressure through the regulation of vascular tone. In response to vascular injury or alterations in local environmental cues, differentiated/contractile VSMCs are capable of switching to a dedifferentiated phenotype characterized by increased proliferation, migration and extracellular matrix synthesis in concert with decreased expression of contractile markers. Imbalanced VSMC plasticity results in maladaptive phenotype alterations that ultimately lead to progression of a variety of VSMC-driven vascular diseases. The nature, extent and consequences of dysregulated VSMC phenotype alterations are diverse, reflecting the numerous environmental cues (e.g. biochemical factors, extracellular matrix components, physical) that prompt VSMC phenotype switching. In spite of decades of efforts to understand cues and processes that normally control VSMC differentiation and their disruption in VSMC-driven disease states, the crucial molecular mechanisms and signalling pathways that shape the VSMC phenotype programme have still not yet been precisely elucidated. In this article we introduce the physiological functions of vascular smooth muscle/VSMCs, outline VSMC-driven cardiovascular diseases and the concept of VSMC phenotype switching, and review molecular mechanisms that play crucial roles in the regulation of VSMC phenotypic plasticity.