Circular RNA circCHFR downregulation protects against oxidized low-density lipoprotein-induced endothelial injury via regulation of microRNA-15b-5p/growth arrest and DNA damage inducible gamma

Higher Expression of miR-15b-5p with Inclusion of Fresh, Lean Beef as Part of a Healthy Dietary Pattern Is Inversely Associated with Markers of Cardiometabolic Disease Risk

BACKGROUND

Considerable controversy exists surrounding the consumption of red meat and its impacts on cardiometabolic health and if it may further impact risk factors at the molecular level.

OBJECTIVE

The purpose of this study was to examine the acute effects of dietary patterns, varying in red meat quantity, on the expression of circulating microRNAs (miRNAs), which are emerging biomarkers of metabolic dysfunction and chronic disease severity.

METHODS

Secondary analyses were performed on plasma samples collected within a randomized, crossover design study in 16 women with overweight (mean ± standard deviation, age = 33 ± 9.89 y; body mass index = 27.9 ± 1.66 kg/m2). Participants were provided with eucaloric, isonitrogenous diets (15% of daily intake as protein) containing either 2 servings of fresh, lean beef/day (BEEF) or 0 servings of fresh, lean beef/day (PLANT) for 7 d/pattern. Fasting blood samples were collected at the end of each dietary pattern for the assessment of 12 circulating metabolic miRNA expression levels (determined a priori by quantitative reverse transcriptase-polymerase chain reaction), plasma glucose, insulin, interleukin-6, tumor necrosis factor-α, C-reactive protein (CRP), adiponectin, glucagon-like peptide-1, and branched-chain amino acids.

RESULTS

Of the 12 miRNAs, miR-15b-5p expression was higher following BEEF versus PLANT (P = 0.024). Increased miR-15b-5p expression correlated with decreased fasting CRP (r = -0.494; P = 0.086) and insulin concentrations (r = -0.670; P = 0.017). miR-15b-5p was inversely correlated with insulin resistance (r = -0.642; P = 0.024) and β cell function (r = -0.646; P = 0.023) and positively correlated with markers of insulin sensitivity (r = 0.520; P = 0.083). However, the correlations were only observed following BEEF, not PLANT.

CONCLUSIONS

These data indicate that the short-term intake of fresh, lean beef as part of a healthy dietary pattern impacts potential biomarkers of cardiometabolic health that are associated with cardiometabolic risk factors in women with overweight. This study was registered at clinicaltrials.gov as NCT02614729.

Broader Perspective on Atherosclerosis-Selected Risk Factors, Biomarkers, and Therapeutic Approach

Atherosclerotic cardiovascular disease (ASCVD) stands as the leading cause of mortality worldwide. At its core lies a progressive process of atherosclerosis, influenced by multiple factors. Among them, lifestyle-related factors are highlighted, with inadequate diet being one of the foremost, alongside factors such as cigarette smoking, low physical activity, and sleep deprivation. Another substantial group of risk factors comprises comorbidities. Amongst others, conditions such as hypertension, diabetes mellitus (DM), chronic kidney disease (CKD), or familial hypercholesterolemia (FH) are included here. Extremely significant in the context of halting progression is counteracting the mentioned risk factors, including through treatment of the underlying disease. What is more, in recent years, there has been increasing attention paid to perceiving atherosclerosis as an inflammation-related disease. Consequently, efforts are directed towards exploring new anti-inflammatory medications to limit ASCVD progression. Simultaneously, research is underway to identify biomarkers capable of providing insights into the ongoing process of atherosclerotic plaque formation. The aim of this study is to provide a broader perspective on ASCVD, particularly focusing on its characteristics, traditional and novel treatment methods, and biomarkers that can facilitate its early detection.

Noncoding RNAs in atherosclerosis: regulation and therapeutic potential

Atherosclerosis, a chronic disease of arteries, results in high mortality worldwide as the leading cause of cardiovascular disease. The development of clinically relevant atherosclerosis involves the dysfunction of endothelial cells and vascular smooth muscle cells. A large amount of evidence indicates that noncoding RNAs, such as microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), are involved in various physiological and pathological processes. Recently, noncoding RNAs were identified as key regulators in the development of atherosclerosis, including the dysfunction of endothelial cells, and vascular smooth muscle cells and it is pertinent to understand the potential function of noncoding RNAs in atherosclerosis development. In this review, the latest available research relates to the regulatory role of noncoding RNAs in the progression of atherosclerosis and the therapeutic potential for atherosclerosis is summarized. This review aims to provide a comprehensive overview of the regulatory and interventional roles of ncRNAs in atherosclerosis and to inspire new insights for the prevention and treatment of this disease.

Circular RNAs: Regulators of endothelial cell dysfunction in atherosclerosis

Endothelial cell (EC) dysfunction is associated with atherosclerosis. Circular RNAs (circRNAs) are covalently closed loops formed by back-splicing, are highly expressed in a tissue-specific or cell-specific manner, and regulate ECs mainly through miRNAs (mircoRNAs) or protein sponges. This review describes the regulatory mechanisms and physiological functions of circRNAs, as well as the differential expression of circRNAs in aberrant ECs. This review focuses on their roles in inflammation, proliferation, migration, angiogenesis, apoptosis, senescence, and autophagy in ECs from the perspective of signaling pathways, such as nuclear factor κB (NF-κB), nucleotide-binding domain, leucine-rich-repeat family, pyrin-domain-containing 3 (NLRP3)/caspase-1, Janus kinase/signal transducer and activator of transcription (JAK/STAT), and phosphoinositide-3 kinase/protein kinase B (PI3K/Akt). Finally, we address the issues and recent advances in circRNAs as well as circRNA-mediated regulation of ECs to improve our understanding of the molecular mechanisms underlying the progression of atherosclerosis and provide a reference for studies on circRNAs that regulate EC dysfunction and thus affect atherosclerosis.

The regulatory role and mechanism of USP14 in endothelial cell pyroptosis induced by coronary heart disease

OBJECTIVE

The present study probes into the role and mechanism of ubiquitin specific peptidase 14 (USP14) in coronary heart disease (CHD)-triggered endothelial cell pyroptosis.

METHODS

An in vitro CHD model was established by inducing human coronary artery endothelial cells (HCAECs) with oxidized low-density lipoprotein (ox-LDL). HCAECs were transfected with si-USP14, followed by evaluation of cell viability by CCK-8 assay, detection of lactate dehydrogenase (LDH) activity by assay kit, detection of USP14, miR-15b-5p, NLRP3, GSDMD-N, and Cleaved-Caspase-1 expressions by qRT-PCR or Western blot, as well as IL-1β and IL-18 concentrations by ELISA. Co-IP confirmed the binding between USP14 and NLRP3. The ubiquitination level of NLRP3 in cells was measured after protease inhibitor MG132 treatment. Dual-luciferase reporter assay verified the targeting relationship between miR-15b-5p and USP14.

RESULTS

USP14 and NLRP3 were highly expressed but miR-15b-5p was poorly expressed in ox-LDL-exposed HCAECs. USP14 silencing strengthened the viability of ox-LDL-exposed HCAECs, reduced the intracellular LDH activity, and diminished the NLRP3, GSDMD-N, Cleaved-Caspase-1, IL-1β, and IL-18 expressions. USP14 bound to NLRP3 protein and curbed its ubiquitination. Repression of NLRP3 ubiquitination counteracted the inhibitory effect of USP14 silencing on HCAEC pyroptosis. miR-15b-5p restrained USP14 transcription and protein expression. miR-15b-5p overexpression alleviated HCAEC pyroptosis by suppressing USP14/NLRP3.

CONCLUSION

USP14 stabilizes NLRP3 protein expression through deubiquitination, thereby facilitating endothelial cell pyroptosis in CHD. miR-15b-5p restrains endothelial cell pyroptosis by targeting USP14 expression.

Exploring the Multifaceted Biologically Relevant Roles of circRNAs: From Regulation, Translation to Biomarkers

CircRNAs are a category of regulatory RNAs that have garnered significant attention in the field of regulatory RNA research due to their structural stability and tissue-specific expression. Their circular configuration, formed via back-splicing, results in a covalently closed structure that exhibits greater resistance to exonucleases compared to linear RNAs. The distinctive regulation of circRNAs is closely associated with several physiological processes, as well as the advancement of pathophysiological processes in several human diseases. Despite a good understanding of the biogenesis of circular RNA, details of their biological roles are still being explored. With the steady rise in the number of investigations being carried out regarding the involvement of circRNAs in various regulatory pathways, understanding the biological and clinical relevance of circRNA-mediated regulation has become challenging. Given the vast landscape of circRNA research in the development of the heart and vasculature, we evaluated cardiovascular system research as a model to critically review the state-of-the-art understanding of the biologically relevant functions of circRNAs. We conclude the review with a discussion of the limitations of current functional studies and provide potential solutions by which these limitations can be addressed to identify and validate the meaningful and impactful functions of circRNAs in different physiological processes and diseases.

Role of Circular RNAs in Atherosclerosis through Regulation of Inflammation, Cell Proliferation, Migration, and Apoptosis: Focus on Atherosclerotic Cerebrovascular Disease

Atherosclerosis (AS) is a disease dangerous to human health and the main pathological cause of ischemic cardiovascular diseases. Although its pathogenesis is not fully understood, numerous basic and clinical studies have shown that AS is a chronic inflammatory disease existing in all stages of atherogenesis. It may be a common link or pathway in the pathogenesis of multiple atherogenic factors. Inflammation is associated with AS complications, such as plaque rupture and ischemic cerebral infarction. In addition to inflammation, apoptosis plays an important role in AS. Apoptosis is a type of programmed cell death, and different apoptotic cells have different or even opposite roles in the process of AS. Unlike linear RNA, circular RNA (circRNA) a covalently closed circular non-coding RNA, is stable and can sponge miRNA, which can affect the stages of AS by regulating downstream pathways. Ultimately, circRNAs play very important roles in AS by regulating inflammation, apoptosis, and some other mechanisms. The study of circular RNAs can provide new ideas for the prediction, prevention, and treatment of AS.

Circular RNAs Variously Participate in Coronary Atherogenesis

Over the past decade, numerous studies have shown that circular RNAs (circRNAs) play a significant role in coronary artery atherogenesis and other cardiovascular diseases. They belong to the class of non-coding RNAs and arise as a result of non-canonical splicing of premature RNA, which results in the formation of closed single-stranded circRNA molecules that lack 5'-end caps and 3'-end poly(A) tails. circRNAs have broad post-transcriptional regulatory activity. Acting as a sponge for miRNAs, circRNAs compete with mRNAs for binding to miRNAs, acting as competing endogenous RNAs. Numerous circRNAs are involved in the circRNA-miRNA-mRNA regulatory axes associated with the pathogenesis of cardiomyopathy, chronic heart failure, hypertension, atherosclerosis, and coronary artery disease. Recent studies have shown that сirc_0001445, circ_0000345, circ_0093887, сircSmoc1-2, and circ_0003423 are involved in the pathogenesis of coronary artery disease (CAD) with an atheroprotective effect, while circ_0002984, circ_0029589, circ_0124644, circ_0091822, and circ_0050486 possess a proatherogenic effect. With their high resistance to endonucleases, circRNAs are promising diagnostic biomarkers and therapeutic targets. This review aims to provide updated information on the involvement of atherogenesis-related circRNAs in the pathogenesis of CAD. We also discuss the main modern approaches to detecting and studying circRNA-miRNA-mRNA interactions, as well as the prospects for using circRNAs as biomarkers and therapeutic targets for the treatment of cardiovascular diseases.

Extracellular vesicles in atherosclerosis and vascular calcification: the versatile non-coding RNAs from endothelial cells and vascular smooth muscle cells

Atherosclerosis (AS) is characterized by the accumulation of lipids, fibrous elements, and calcification in the innermost layers of arteries. Vascular calcification (VC), the deposition of calcium and phosphate within the arterial wall, is an important characteristic of AS natural history. However, medial arterial calcification (MAC) differs from intimal calcification and cannot simply be explained as the consequence of AS. Endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are directly involved in AS and VC processes. Understanding the communication between ECs and VSMCs is critical in revealing mechanisms underlying AS and VC. Extracellular vesicles (EVs) are found as intercellular messengers in kinds of physiological processes and pathological progression. Non-coding RNAs (ncRNAs) encapsulated in EVs are involved in AS and VC, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). The effects of ncRNAs have not been comprehensively understood, especially encapsulated in EVs. Some ncRNAs have demonstrated significant roles in AS and VC, but it remains unclear the functions of the majority ncRNAs detected in EVs. In this review, we summarize ncRNAs encapsulated in EC-EVs and VSMC-EVs, and the signaling pathways that are involved in AS and VC.

Circular RNA as Therapeutic Targets in Atherosclerosis: Are We Running in Circles?

Much attention has been paid lately to harnessing the diagnostic and therapeutic potential of non-coding circular ribonucleic acids (circRNAs) and micro-RNAs (miRNAs) for the prevention and treatment of cardiovascular diseases. The genetic environment that contributes to atherosclerosis pathophysiology is immensely complex. Any potential therapeutic application of circRNAs must be assessed for risks, benefits, and off-target effects in both the short and long term. A search of the online PubMed database for publications related to circRNA and atherosclerosis from 2016 to 2022 was conducted. These studies were reviewed for their design, including methods for developing atherosclerosis and the effects of the corresponding atherosclerotic environment on circRNA expression. Investigated mechanisms were recorded, including associated miRNA, genes, and ultimate effects on cell mechanics, and inflammatory markers. The most investigated circRNAs were then further analyzed for redundant, disparate, and/or contradictory findings. Many disparate, opposing, and contradictory effects were observed across experiments. These include levels of the expression of a particular circRNA in atherosclerotic environments, attempted ascertainment of the in toto effects of circRNA or miRNA silencing on atherosclerosis progression, and off-target, cell-specific, and disease-specific effects. The high potential for detrimental and unpredictable off-target effects downstream of circRNA manipulation will likely render the practice of therapeutic targeting of circRNA or miRNA molecules not only complicated but perilous.

Noncoding RNAs as Key Regulators for Cardiac Development and Cardiovascular Diseases

Noncoding RNAs (ncRNAs) play fundamental roles in cardiac development and cardiovascular diseases (CVDs), which are a major cause of morbidity and mortality. With advances in RNA sequencing technology, the focus of recent research has transitioned from studies of specific candidates to whole transcriptome analyses. Thanks to these types of studies, new ncRNAs have been identified for their implication in cardiac development and CVDs. In this review, we briefly describe the classification of ncRNAs into microRNAs, long ncRNAs, and circular RNAs. We then discuss their critical roles in cardiac development and CVDs by citing the most up-to-date research articles. More specifically, we summarize the roles of ncRNAs in the formation of the heart tube and cardiac morphogenesis, cardiac mesoderm specification, and embryonic cardiomyocytes and cardiac progenitor cells. We also highlight ncRNAs that have recently emerged as key regulators in CVDs by focusing on six of them. We believe that this review concisely addresses perhaps not all but certainly the major aspects of current progress in ncRNA research in cardiac development and CVDs. Thus, this review would be beneficial for readers to obtain a recent picture of key ncRNAs and their mechanisms of action in cardiac development and CVDs.

Exosomes in Cardiovascular Disease: From Mechanism to Therapeutic Target

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. In recent decades, clinical research has made significant advances, resulting in improved survival and recovery rates for patients with CVD. Despite this progress, there is substantial residual CVD risk and an unmet need for better treatment. The complex and multifaceted pathophysiological mechanisms underlying the development of CVD pose a challenge for researchers seeking effective therapeutic interventions. Consequently, exosomes have emerged as a new focus for CVD research because their role as intercellular communicators gives them the potential to act as noninvasive diagnostic biomarkers and therapeutic nanocarriers. In the heart and vasculature, cell types such as cardiomyocytes, endothelial cells, vascular smooth muscle, cardiac fibroblasts, inflammatory cells, and resident stem cells are involved in cardiac homeostasis via the release of exosomes. Exosomes encapsulate cell-type specific miRNAs, and this miRNA content fluctuates in response to the pathophysiological setting of the heart, indicating that the pathways affected by these differentially expressed miRNAs may be targets for new treatments. This review discusses a number of miRNAs and the evidence that supports their clinical relevance in CVD. The latest technologies in applying exosomal vesicles as cargo delivery vehicles for gene therapy, tissue regeneration, and cell repair are described.

Circular RNA circ_0029589 promotes ox-LDL-induced endothelial cell injury through regulating RAB22A by serving as a sponge of miR-1197

BACKGROUND

Dysfunction of endothelial cells is now considered a vital contributor to the pathogenesis of atherosclerosis (AS). Moreover, circular RNA (circRNA) circ_0029589 has been found to be involved in the regulation of oxidized low-density lipoprotein (ox-LDL)-induced endothelial cell damage. Nevertheless, its molecular mechanism in ox-LDL-triggered endothelial cell injury is poorly defined.

METHODS

Human umbilical vein endothelial cells (HUVECs) treated with ox-LDL were applied as cell models of AS. Circ_0029589, microRNA-1197 (miR-1197), and Ras-related protein Rab-22A (RAB22A) expression were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, apoptosis, angiogenesis, and invasion were detected using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, tube formation, and transwell assays. Western blot analysis of Cleaved-caspase-3, B-cell lymphoma-2 related X protein (Bax), and RAB22A. IL-6, IL-1β, and Tumor necrosis factor α (TNF-α) levels were gauged using ELISA kits. Superoxide Dismutase (SOD) activity and Malondiahyde (MDA) level were assessed using special kits. Bioinformatics software predicted the binding between miR-1197 and circ_0029589 or RAB22A, which was proved using dual-luciferase reporter and RNA pull-down assays.

RESULTS

Circ_0029589 and RAB22A expression were strengthened, and miR-1197 was reduced in ox-LDL-treated HUVECs. Importantly, circ_0029589 silencing ameliorated ox-LDL-triggered HUVEC damage via promoting cell proliferation, tube formation ability, invasion, and repressing cell apoptosis, inflammation, and oxidative stress. Mechanical analysis suggested that circ_0029589 might affect RAB22A content through sponging miR-1197.

CONCLUSION

Circ_0090231 might protect against ox-LDL-mediated HUVEC injury via the miR-1197/RAB22A axis, which provides a therapeutic strategy for endothelial cell damage of AS.

A Comprehensive Review on Function of miR-15b-5p in Malignant and Non-Malignant Disorders

miR-15b-5p is encoded by MIR15B gene. This gene is located on cytogenetic band 3q25.33. This miRNA participates in the pathogenesis of several cancers as well as non-malignant conditions, such as abdominal aortic aneurysm, Alzheimer’s and Parkinson’s diseases, cerebral ischemia reperfusion injury, coronary artery disease, dexamethasone induced steatosis, diabetic complications and doxorubicin-induced cardiotoxicity. In malignant conditions, both oncogenic and tumor suppressor impacts have been described for miR-15b-5p. Dysregulation of miR-15b-5p in clinical samples has been associated with poor outcome in different kinds of cancers. In this review, we discuss the role of miR-15b-5p in malignant and non-malignant conditions.