Atherosclerosis revisited from a clinical perspective: still an inflammatory disease?

Circ_0026218 ameliorates oxidized low-density lipoprotein-induced vascular endothelial cell dysfunction by regulating miR-188-3p/TLR4/NF-κB pathway

BACKGROUND

Circular RNAs (circRNAs) have shown important regulatory roles in cardiovascular diseases, including atherosclerosis (AS). However, the role and mechanism of circ_0026218 in AS remain unclear.

METHODS

The cell model of AS in vitro was established by stimulating human umbilical vein endothelial cells (HUVECs) with oxidized low-density lipoprotein (ox-LDL). In addition, circ_0026218, microRNA-188-3p (miR-188-3p), and toll-like receptor 4 (TLR4) expression was determined via real-time quantitative polymerase chain reaction (RT-qPCR) in serum samples from AS patients and healthy volunteers. Cell proliferation was assessed using Cell Counting Kit-8 (CCK-8) assay and 5-ethynyl-2'-deoxyuridine (EdU) assay. Cell apoptosis was measured using flow cytometry. The inflammatory response was assessed using enzyme-linked immunosorbent assay (ELISA). Oxidative stress level was assessed using corresponding kits. Nitric oxide (NO) level was examined using NO detection assay. The interaction between miR-188-3p and circ_0026218 or TLR4 was determined via dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays. Exosomes were observed using transmission electron microscopy (TEM). The size distribution of exosomes was analyzed using nanoparticle tracking analysis (NTA).

RESULTS

Ox-LDL treatment caused HUVEC dysfunction by inhibiting cell proliferation and promoting apoptosis, inflammation, and oxidative stress. Circ_0026218 was upregulated in AS serum samples and ox-LDL-treated HUVECs. Knockdown of circ_0026218 attenuated ox-LDL-induced dysfunction in HUVECs. MiR-188-3p acted as a target of circ_0026218, and miR-188-3p downregulation reversed the suppression role of circ_0026218 knockdown on ox-LDL-induced HUVEC disorder. TLR4 was a target of miR-188-3p, and miR-188-3p overexpression alleviated ox-LDL-induced dysfunction in HUVECs by targeting TLR4. Circ_0026218 could deregulate the TLR4/NF-κB pathway by sponging the miR-188-3p. Importantly, circ_0026218 was overexpressed in exosomes from ox-LDL-treated HUVECs and could be delivered via exosomes.

CONCLUSION

Circ_0026218 knockdown attenuated ox-LDL-induced dysfunction in HUVECs via regulating miR-188-3p/TLR4/NF-κB pathway.

Astragaloside IV protects against oxidized low-density lipoprotein-induced injury in human umbilical vein endothelial cells via the histone deacetylase 9 (HDAC9)/NF-κB axis

BACKGROUND

Atherosclerosis is a main cause of multiple cardiovascular diseases, and cell damage of human umbilical vein endothelial cells (HUVECs) was reported to participate in the development of atherosclerosis. In this study, we aimed to study the action of Astragaloside IV (ASV) on AS development using in vitro AS cell model.

METHODS

MTT assay, EdU staining assay, and flow cytometry were utilized for detection of cell proliferation and apoptosis, respectively. The protein expression of histone deacetylase 9 (HDAC9), Bax, Bcl-2, p-P65, P65, p-IκBα, and IκBα was gaged using western blot. The angiogenesis was evaluated by tube formation assay. The inflammatory response was evaluated by ELISA kits. SOD activity and MDA level were detected using the matched commercial kits. RT-qPCR was used for HDAC9 mRNA expression measurement.

RESULTS

Oxidized low-density lipoprotein (ox-LDL) significantly repressed cell proliferation, angiogenesis, and enhanced apoptosis, inflammation, and oxidative stress in HUVECs. ASV addition could alleviate ox-LDL-caused cell damage in HUVECs. Moreover, HDAC9 was overexpressed in AS patients and AS cell model. Functionally, HDAC9 knockdown also exhibited the protective role in ox-LDL-treated HUVECs. In addition, ASV treatment protected against ox-LDL-induced damage in HUVECs via targeting HDAC9. ASV could inactivate the NF-κB pathway via regulating HDAC9 in AS cell model.

CONCLUSION

ASV exerted the protective effects on ox-LDL-induced damage in HUVECs through the HDAC9/NF-κB axis.

Piezo1 in vascular remodeling of atherosclerosis and pulmonary arterial hypertension: A potential therapeutic target

Vascular remodeling (VR) is a structural and functional change of blood vessels to adapt to the changes of internal and external environment. It is one of the common pathological features of many vascular proliferative diseases. The process of VR is mainly manifested in the changes of vascular wall structure and function, including intimal hyperplasia, thickening or thinning of media, fibrosis of adventitia, etc. These changes are also the pathological basis of aging and various cardiovascular diseases. Mechanical force is the basis of cardiovascular biomechanics, and the newly discovered mechanical sensitive ion channel Piezo1 is widely distributed in the whole cardiovascular system. Studies have confirmed that Piezo1, a mechanically sensitive ion channel, plays an important role in cardiovascular remodeling diseases. This article reviews the molecular mechanism of Piezo1 in atherosclerosis, hypertension and pulmonary hypertension, in order to provide a theoretical basis for the further study of vascular remodeling.

Circular RNA circ_0002984 Promotes Cell Proliferation and Migration by Regulating miR-181b-5p/Vascular Endothelial Growth Factor Axis and PI3K-AKT Signaling Pathway in Oxidized Low-Density Lipoprotein-Treated Vascular Smooth Muscle Cells

ABSTRACT

RNAs (circRNAs) play critical roles in many diseases, including atherosclerosis (AS). However, the role and underlying mechanism of circ_0002984 in AS remain unclear. Vascular smooth muscle cells (VSMCs) treated with oxidized low-density lipoprotein (ox-LDL) were used as a AS cell model. Quantitative real-time polymerase chain reaction was conducted to detect the expression of circ_0002984, miR-181b-5p and vascular endothelial growth factor A (VEGFA). Cell proliferation was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide assay and 5-ethynyl-2'-deoxyuridine assays. Cell migration was assessed using wound healing assay and transwell assay. All protein levels were analyzed by western blot assay. The interaction between miR-181b-5p and circ_0002984 or VEGFA was confirmed by dual-luciferase reporter, RNA Immunoprecipitation, and RNA pull-down assays. Circ_0002984 and VEGFA were overexpressed, and miR-181b-5p was downregulated in serum of AS patients and ox-LDL-stimulated VSMCs. Circ_0002984 silencing inhibited ox-LDL-induced proliferation and migration in VSMCs. MiR-181b-5p was a target of circ_0002984, and miR-181b-5p inhibition counteracted the suppressing effects of circ_0002984 downregulation on proliferation and migration in ox-LDL-stimulated VSMCs. Additionally, VEGFA was a downstream target of miR-181b-5p and VEGFA upregulation abolished the suppressive influence of miR-181b-5p on proliferation and migration in ox-LDL-exposed VSMCs. Furthermore, circ_0002984 depletion blocked phosphatidylinositol 3 kinase-AKT signaling pathway by regulating miR-181b-5p and VEGFA. Circ_0002984 downregulation suppressed cell proliferation and migration by regulating miR-181b-5p/VEGFA axis and phosphatidylinositol 3 kinase-AKT pathway in ox-LDL-stimulated VEGFA, providing a new mechanism for AS pathogenesis.

Circular RNA circLMF1 regulates PDGF-BB-induced proliferation and migration of human aortic smooth muscle cells by regulating the miR-125a-3p/VEGFA or FGF1 axis

Atherosclerosis is a major cause of cardiovascular disease, in which vascular smooth muscle cells (VSMCs) proliferation and migration play a vital role. Circular RNAs (circRNAs) have been reported to be correlated with the VSMCs function. Therefore, this study is designed to explore the role and mechanism of circRNA lipase maturation factor 1 (circLMF1) in Human aortic VSMCs (HASMCs). The microarray was used for detecting the expression of circLMF1 in proliferative and quiescent HASMCs. Levels of circLMF1, microRNA-125a-3p (miR-125a-3p), vascular endothelial growth factor A (VEGFA), and fibroblast growth factor 1 (FGF1) were determined by real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability, cell cycle progression, and migration were assessed by Cell Counting Kit-8 (CCK-8), flow cytometry, wound healing, and transwell assays, respectively. Western blot assay determined proliferating cell nuclear antigen (PCNA), Cyclin D1, matrix metalloproteinase (MMP2), osteopontin (OPN), VEGFA, and FGF1 protein levels. The possible interactions between miR-125a-3p and circLMF1, and miR-125a-3p and VEGFA or FGF1 were predicted by circbank or targetscan, and then verified by a dual-luciferase reporter, RNA Immunoprecipitation (RIP), RNA pull-down assays. CircLMF1, VEGFA, and FGF1 were increased, and miR-125a-3p was decreased in platelet-derived growth factor-BB (PDGF-BB)-inducted HASMCs. Functionally, circLMF1 knockdown hindered cell viability, cell cycle progression, and migration in PDGF-BB-treated HASMCs. Mechanically, circLMF1 could regulate VEGFA or FGF1 expression through sponging miR-125a-3p. Our findings revealed that circLMF1 deficiency could inhibit cell viability, cell cycle progression, and migration of PDGF-BB stimulated atherosclerosis model partly through the miR-125a-3p/VEGFA or FGF1 axis, suggesting that targeting circLMF1 can be a feasible therapeutic strategy for atherosclerosis.

Beyond Self-Recycling: Cell-Specific Role of Autophagy in Atherosclerosis

Atherosclerosis is a chronic inflammatory disease of the arterial vessel wall and underlies the development of cardiovascular diseases, such as myocardial infarction and ischemic stroke. As such, atherosclerosis stands as the leading cause of death and disability worldwide and intensive scientific efforts are made to investigate its complex pathophysiology, which involves the deregulation of crucial intracellular pathways and intricate interactions between diverse cell types. A growing body of evidence, including in vitro and in vivo studies involving cell-specific deletion of autophagy-related genes (ATGs), has unveiled the mechanistic relevance of cell-specific (endothelial, smooth-muscle, and myeloid cells) defective autophagy in the processes of atherogenesis. In this review, we underscore the recent insights on autophagy's cell-type-dependent role in atherosclerosis development and progression, featuring the relevance of canonical catabolic functions and emerging noncanonical mechanisms, and highlighting the potential therapeutic implications for prevention and treatment of atherosclerosis and its complications.

Heat Shock Protein 60 Antibodies Are Associated With a Risk Factor for Cardiovascular Disease in Bedridden Elderly Patients

Frailty, in elderly people, represents multiple deficiencies in different organs and is characterized by decreased physiological reserves and greater vulnerability to stressors. Bedridden elderly, with cardiovascular disease (CVD), have a worse prognosis than non-bedridden patients. Heat-shock proteins (HSPs) are molecular chaperones that under physiological conditions facilitate the transport, folding and assembly of proteins. Serum HSP 60-kDa concentrations and their antibodies are increased, in response to non-physiological conditions, suggesting the involvement of HSPs and their antibodies in the development of CVD. The aim of this work was to evaluate heat shock protein 60 and anti-HSP60 antibody levels, associated with a risk factor for cardiovascular disease, in bedridden elderly patients. Clinical, analytical and cross-sectional analyses were performed with 57 elderly (>65 years). HSP60 and anti-HSP60 plasma levels were measured by ELISA. Bivariate analysis using a linear regression model adjusted for risk factors used Framingham Score. Among the 57 elderly, with an average age of 69.89 years, 39% are bedridden; 26% with pre-existing cardiovascular disease and 44% are dyslipidemic. The relationship of risk factors in the Framingham Score was positive for the anti-HSP60 antibody (p = 0.042) measurement. Our data show a positive correlation among the elevation of the Framingham score and the profile of anti-HSP60 antibodies. These results suggest a greater immune activation that is associated with cardiovascular risk and bedridden fragility.

LncRNA TNK2-AS1 regulated ox-LDL-stimulated HASMC proliferation and migration via modulating VEGFA and FGF1 expression by sponging miR-150-5p

Long non‐coding RNAs (lncRNAs) have been indicated for the regulatory roles in cardiovascular diseases. This study determined the expression of lncRNA TNK2 antisense RNA 1 (TNK2‐AS1) in oxidized low‐density lipoprotein (ox‐LDL)‐stimulated human aortic smooth muscle cells (HASMCs) and examined the mechanistic role of TNK2‐AS1 in the proliferation and migration of HASMCs. Our results demonstrated that ox‐LDL promoted HASMC proliferation and migration, and the enhanced proliferation and migration in ox‐LDL‐treated HASMCs were accompanied by the up‐regulation of TNK2‐AS1. In vitro functional studies showed that TNK2‐AS1 knockdown suppressed cell proliferation and migration of ox‐LDL‐stimulated HASMCs, while TNK2‐AS1 overexpression enhanced HASMC proliferation and migration. Additionally, TNK2‐AS1 inversely regulated miR‐150‐5p expression via acting as a competing endogenous RNA (ceRNA), and the enhanced effects of TNK2‐AS1 overexpression on HASMC proliferation and migration were attenuated by miR‐150‐5p overexpression. Moreover, miR‐150‐5p could target the 3’ untranslated regions of vascular endothelial growth factor A (VEGFA) and fibroblast growth factor 1 (FGF1) to regulate FGF1 and VEGFA expression in HASMCs, and the inhibitory effects of miR‐150‐5p overexpression in ox‐LDL‐stimulated HASMCs were attenuated by enforced expression of VEGFA and FGF1. Enforced expression of VEGFA and FGF1 also partially restored the suppressed cell proliferation and migration induced by TNK2‐AS1 knockdown in ox‐LDL‐stimulated HASMCs, while the enhanced effects of TNK2‐AS1 overexpression on HASMC proliferation and migration were attenuated by the knockdown of VEGFA and FGF1. Collectively, our findings showed that TNK2‐AS1 exerted its action in ox‐LDL‐stimulated HASMCs via regulating VEGFA and FGF1 expression by acting as a ceRNA for miR‐150‐5p.

High dose rosuvastatin increases ABCA1 transporter in human atherosclerotic plaques in a cholesterol-independent fashion

BACKGROUND

ATP-binding cassette A1 (ABCA1) and G1 (ABCG1) mediate cholesterol efflux from lipid-laden macrophages, thus promoting anti-atherosclerotic outcomes. The mechanism(s) linking treatment with statins and ABCA1/ABCG1 in human atherosclerosis are not fully understood and require further investigation. Therefore, we studied whether short-term treatment with low- or high-dose rosuvastatin may affect ABCA1 and ABCG1 expression in human atherosclerotic plaques.

METHODS

Seventy patients with severe stenosis of the internal carotid artery were randomized to receive low (10 mg/day) or high (40 mg/day) dose rosuvastatin for 12 weeks before elective endarterectomy. As controls, we analyzed a reference group of 10 plaques from subjects with hypercholesterolemia but not receiving statin treatment and an additional set of 11 plaques collected from normocholesterolemic patients. On atherosclerotic plaques, ABCA1 and ABCG1 expression was evaluated at RNA level by qPCR and at protein level by immunoblotting and immunohistochemistry.

RESULTS

Both rosuvastatin doses were associated with lower plaque ABCA1 mRNA levels and with a trend toward reduction for ABCG1. However, ABCA1 protein was paradoxically higher in patients treated with high-dose rosuvastatin and was associated with lower levels of miR-33b-5p, a microRNA known as a regulator of ABCA1. Multivariate analyses showed that the effect is cholesterol-independent. Finally, no effects were found for ABCG1 protein.

CONCLUSIONS

High-dose rosuvastatin increases macrophage ABCA1 protein levels in human atherosclerotic plaque despite mRNA reduction in a mechanism unrelated to plasma cholesterol reduction and potentially involving miR-33b-5p. This pathway may reflect an additional feature contributing to the anti-atherosclerotic effect for high-dose rosuvastatin.

TRIAL REGISTRATION

ISRCTN16590640.

MiR-146a Regulates Neutrophil Extracellular Trap Formation That Predicts Adverse Cardiovascular Events in Patients With Atrial Fibrillation

OBJECTIVE

Atrial fibrillation (AF) patients experience adverse cardiovascular events (ACEs) despite anticoagulant therapy. We reported that rs2431697 of miR-146a, a negative regulator of inflammation, predicts ACEs in patients with AF. The relationship between neutrophil extracellular traps and thrombogenesis is known. Thus, our aim was to evaluate the role of neutrophil extracellular trap compounds as prognostic markers of ACEs in AF and to study whether miR-146a affects NETosis.

APPROACH AND RESULTS

We included 336 steadily anticoagulated AF patients with a median follow-up of 7.9 years (interquartile range, 7.3-8.1) and 127 healthy subjects. The reviewed ACEs included stroke (ischemic/embolic), acute coronary syndrome, acute heart failure, and global or vascular death. We quantified cell-free DNA and NE (neutrophil elastase) at diagnosis. Rs2431697 was genotyped. Neutrophils from human and mice were seeded to analyze shed cell-free DNA and H3cit (citrullinated histone 3) after activation. In human plasmas, higher NE levels (>55.29 ng/mL), but not cell-free DNA, were independently associated with higher risk of all-cause mortality (hazard ratio, 2.24; 95% CI, 1.36-3.68), cardiovascular mortality (hazard ratio, 4.77; 95% CI, 1.11-20.47), and composite cardiovascular events (hazard ratio, 1.84; 95% CI, 1.01-3.76). In patients, NE levels were associated with rs2431697 (TT: 51.82±2.73 versus CC: 40.01±3.05 ng/mL; P=0.040). In vitro, both human (TT for rs2431697) and miR-146a^-/- mice neutrophils yielded higher levels of cell-free DNA and H3cit than CC or wild-type cells, respectively.

CONCLUSIONS

NE activity can provide new ACE prognostic information in AF patients. These findings provide evidence of a potential role of miR-146a in neutrophil extracellular trap generation and cardiovascular risk in AF.

Perpetual change: autophagy, the endothelium, and response to vascular injury

Current studies of vascular health, aging, and autophagy emphasize how the endothelium adapts to stress and contributes to disease. The endothelium is far from an inert barrier to blood-borne cells, pathogens, and chemical signals; rather, it actively translates circulating mediators into tissue responses, changing rapidly in response to physiologic stressors. Macroautophagy-the cellular ingestion of effete organelles and protein aggregates to provide anabolic substrates to fuel bioenergetics in times of stress-plays an important role in endothelial cell homeostasis, vascular remodeling, and disease. These roles include regulating vascular tone, sustaining or limiting cell survival, and contributing to the development of atherosclerosis secondary to infection, inflammation, and angiogenesis. Autophagy modulates these critical functions of the endothelium in a dynamic and perpetual response to tissue and intravascular cues.