Emerging Roles of Extracellular Vesicle-Delivered Circular RNAs in Atherosclerosis

Long non-coding RNAs and their role in muscle regeneration

In mammals, most of the genome is transcribed to generate a large and heterogeneous variety of non-protein coding RNAs, that are broadly grouped according to their size. Long noncoding RNAs include a very large and versatile group of molecules. Despite only a minority of them has been functionally characterized, there is emerging evidence indicating long noncoding RNAs as important regulators of expression at multiple levels. Several of them have been shown to be modulated during myogenic differentiation, playing important roles in the regulation of skeletal muscle development, differentiation and homeostasis, and contributing to neuromuscular diseases. In this chapter, we have summarized the current knowledge about long noncoding RNAs in skeletal muscle and discussed specific examples of long noncoding RNAs (lncRNAs and circRNAs) regulating muscle stem cell biology. We have also discussed selected long noncoding RNAs involved in the most common neuromuscular diseases.

HAND2-AS1 associates with outcomes of acute coronary syndrome and regulates cell viability of vascular endothelial cells

OBJECTIVE

Acute coronary syndrome (ACS) is an emergency and severe disorder of the cardiovascular system. This paper assessed the expression of plasma HAND2-AS1 in patients with ACS, researched its diagnostic and prognostic significance, and studied its possible mechanism for participating in ACS.

METHODS

The concentration of HAND2-AS1 of 101 included patients with ACS was certified by qRT-PCR and its possible diagnostic function was revealed by the receiver operating characteristic (ROC) curve. All patients were followed up for 6 months after percutaneous coronary intervention (PCI) therapy and Kaplan-Meier (K-M) curve and COX regression analysis was performed to estimate the short-term prognostic value of HAND2-AS1 in ACS. The interrelationship between HAND2-AS1 and Gensini score and endothelial injury was identified via Pearson correlation. The function of HAND2-AS1 on the viability, migration, and apoptosis of human umbilical vein endothelial cells (HUVECs) was estimated by the Cell Counting Kit-8 (CCK-8), Transwell chamber, and flow cytometry.

RESULTS

In ACS patients, the expression of serum HAND2-AS1 was prominently decreased and closely correlated with the Gensini score. The decreased HAND2-AS1 expression was of diagnostic significance. Declined plasma HAND2-AS1 was observed in patients with the major adverse cardio-cerebrovascular event (MACCE) and was an independent risk for the poor prognosis of ACS patients. In the cell model, upregulation of HAND2-AS1 improved cell viability and migration and inhibited cell apoptosis.

CONCLUSION

HAND2-AS1 was an independent biomarker for the diagnosis and prognosis of ACS. HAND2-AS1 might be involved in ACS development by regulating endothelial damage.

Epigenetic modifications in obesity-associated diseases

The global prevalence of obesity has reached epidemic levels, significantly elevating the susceptibility to various cardiometabolic conditions and certain types of cancer. In addition to causing metabolic abnormalities such as insulin resistance (IR), elevated blood glucose and lipids, and ectopic fat deposition, obesity can also damage pancreatic islet cells, endothelial cells, and cardiomyocytes through chronic inflammation, and even promote the development of a microenvironment conducive to cancer initiation. Improper dietary habits and lack of physical exercise are important behavioral factors that increase the risk of obesity, which can affect gene expression through epigenetic modifications. Epigenetic alterations can occur in early stage of obesity, some of which are reversible, while others persist over time and lead to obesity-related complications. Therefore, the dynamic adjustability of epigenetic modifications can be leveraged to reverse the development of obesity-associated diseases through behavioral interventions, drugs, and bariatric surgery. This review provides a comprehensive summary of the impact of epigenetic regulation on the initiation and development of obesity-associated cancers, type 2 diabetes, and cardiovascular diseases, establishing a theoretical basis for prevention, diagnosis, and treatment of these conditions.

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.

Plasma Pattern of Extracellular Vesicles Isolated from Hepatitis C Virus Patients and Their Effects on Human Vascular Endothelial Cells

Hepatitis C virus (HCV) patients are at increased risk of cardiovascular disease (CVD). In this study, we aimed to evaluate the role of extracellular vesicles (EVs) as pathogenic factors for the onset of HCV-related endothelial dysfunction. Sixty-five patients with various stages of HCV-related chronic liver disease were enrolled in this case series. Plasma EVs were characterized and used to stimulate human vascular endothelial cells (HUVEC), which were examined for cell viability, mitochondrial membrane potential, and reactive oxygen species (ROS) release. The results showed that EVs from HCV patients were mainly of endothelial and lymphocyte origin. Moreover, EVs were able to reduce cell viability and mitochondrial membrane potential of HUVEC, while increasing ROS release. Those harmful effects were reduced by the pretreatment of HUVEC with the NLR family pyrin domain containing 3 (NLRP3)/AMP-activated protein kinase and protein kinase B blockers. In conclusion, in HCV patients, we could highlight a circulating pattern of EVs capable of inducing damage to the endothelium. These data represent a novel possible pathogenic mechanism underlying the reported increase of CVD occurrence in HCV infection and could be of clinical relevance also in relation to the widespread use of antiviral drugs.

CircRnas in atherosclerosis, with special emphasis on the spongy effect of circRnas on miRnas

Atherosclerosis (AS) is a chronic inflammatory disease, which leads to atherosclerotic rupture, lumen stenosis and thrombosis, and often endangers life. Circular RNAs (circRNAs) are a special class of non-coding RNA molecules, whose abnormal expression has been proved to be closely related to human diseases, including AS. Both the abnormal regulation of circRNAs and the sponging effect on miRNAs would lead to changes in gene expression in the form of epigenetic modification, ultimately leading to the formation of AS. CircRNAs can be used as peripheral blood markers of AS, and play an important regulatory role in the proliferation, migration, inflammation and apoptosis of vascular smooth muscle cells, endothelial cells and macrophage, which are key cells for the development of AS. The in-depth understanding of circRNAs in AS not only provides a new method for the diagnosis of AS, but also provides a new idea for the treatment of AS.

Role of Inflammation in Cardiac Remodeling After Acute Myocardial Infarction

Atherosclerosis is defined as an inflammatory disease. Low-grade inflammation is present in all phases of the cardiovascular continuum, since the establishment of cardiovascular risk factors and ischemic heart disease until cardiovascular events, such as myocardial infarction, heart failure and death. Not all inflammatory pathways are linked to cardiovascular outcomes, and thus, not all anti-inflammatory approaches decrease cardiovascular events. The most common cause of ventricular remodeling and heart failure is ischemic heart disease. Biomarkers such as high-sensitivity C-reactive protein can identify individuals at risk of major cardiovascular complications, but this biomarker has no causal effect on cardiovascular disease. On the other hand, interleukin 6 appears to be causally associated with cardiovascular disease. CANTOS was the first proof of concept study showing that anti-inflammatory therapy reduces major cardiovascular outcomes. Based on many anti-inflammatory trials, only therapies acting on the NLRP3 inflammasome, or interleukin 1beta, showed benefits on cardiovascular disease. Ventricular remodeling, particularly after myocardial infarction seems also influenced by the intensity of inflammatory responses, suggesting that anti-inflammatory therapies may reduce the residual cardiovascular risk. Inflammasome (NLRP3) activation, subtypes of lymphocytes, interleukin 6, and some inflammatory biomarkers, are associated with larger infarct size and impaired ventricular function after myocardial infarction. Cardiovascular risk factors commonly present in patients with myocardial infarction, and advanced age are associated with higher inflammatory activity.