Extracellular vesicles derived from endothelial cells in hypoxia contribute to pulmonary artery smooth muscle cell proliferation in-vitro and pulmonary hypertension in mice

Harmonising cellular conversations: decoding the vital roles of extracellular vesicles in respiratory system intercellular communications

Extracellular vesicles (EVs) released by various cells play crucial roles in intercellular communication within the respiratory system. This review explores the historical context and significance of research into extracellular vesicles. Categorised into exosomes (sized 30-150 nm), microvesicles (sized 50-1000 nm) and apoptotic bodies (sized 500-2000nm), based on their generation mechanisms, extracellular vesicles carry diverse cargoes of biomolecules, including proteins, lipids and nucleic acids. Respiratory ailments are the primary contributors to both mortality and morbidity across various populations globally, significantly impacting public health. Recent studies have underscored the pivotal role of extracellular vesicles, particularly their cargo content, in mediating intercellular communication between lung cells in respiratory diseases. This comprehensive review provides insights into extracellular vesicle mechanisms and emphasises their significance in major respiratory conditions, including acute lung injury, COPD, pulmonary hypertension, pulmonary fibrosis, asthma and lung cancer.

Insight into endothelial cell-derived extracellular vesicles in cardiovascular disease: Molecular mechanisms and clinical implications

The endothelium is crucial in regulating vascular function. Extracellular vesicles (EVs) serve as membranous structures released by cells to facilitate intercellular communication through the delivery of nucleic acids, lipids, and proteins to recipient cells in an paracrine or endocrine manner. Endothelial cell-derived EVs (EndoEVs) have been identified as both biomarkers and significant contributors to the occurrence and progression of cardiovascular disease (CVD). The impact of EndoEVs on CVD is complex and contingent upon the condition of donor cells, the molecular cargo within EVs, and the characteristics of recipient cells. Consequently, elucidating the underlying molecular mechanisms of EndoEVs is crucial for comprehending their contributions to CVD. Moreover, a thorough understanding of the composition and function of EndoEVs is imperative for their potential clinical utility. This review aims provide an up-to-date overview of EndoEVs in the context of physiology and pathophysiology, as well as to discuss their prospective clinical applications.

Extracellular vesicles in venous thromboembolism and pulmonary hypertension

Venous thromboembolism (VTE) is a multifactorial disease, and pulmonary hypertension (PH) is a serious condition characterized by pulmonary vascular remodeling leading with increased pulmonary vascular resistance, ultimately leading to right heart failure and death. Although VTE and PH have distinct primary etiologies, they share some pathophysiologic similarities such as dysfunctional vasculature and thrombosis. In both conditions there is solid evidence that EVs derived from a variety of cell types including platelets, monocytes, endothelial cells and smooth muscle cells contribute to vascular endothelial dysfunction, inflammation, thrombosis, cellular activation and communications. However, the roles and importance of EVs substantially differ between studies depending on experimental conditions and parent cell origins of EVs that modify the nature of their cargo. Numerous studies have confirmed that EVs contribute to the pathophysiology of VTE and PH and increased levels of various EVs in relation with the severity of VTE and PH, confirming its potential pathophysiological role and its utility as a biomarker of disease severity and as potential therapeutic targets.

A Machine Learning Model Based on microRNAs for the Diagnosis of Essential Hypertension

INTRODUCTION

Hypertension is a major and modifiable risk factor for cardiovascular diseases. Essential, primary, or idiopathic hypertension accounts for 90-95% of all cases. Identifying novel biomarkers specific to essential hypertension may help in understanding pathophysiological pathways and developing personalized treatments. We tested whether the integration of circulating microRNAs (miRNAs) and clinical risk factors via machine learning modeling may provide useful information and novel tools for essential hypertension diagnosis and management.

MATERIALS AND METHODS

In total, 174 participants were enrolled in the present observational case-control study, among which, there were 89 patients with essential hypertension and 85 controls. A discovery phase was conducted using small RNA sequencing in whole blood samples obtained from age- and sex-matched hypertension patients (n = 30) and controls (n = 30). A validation phase using RT-qPCR involved the remaining 114 participants. For machine learning, 170 participants with complete data were used to generate and evaluate the classification model.

RESULTS

Small RNA sequencing identified seven miRNAs downregulated in hypertensive patients as compared with controls in the discovery group, of which six were confirmed with RT-qPCR. In the validation group, miR-210-3p/361-3p/362-5p/378a-5p/501-5p were also downregulated in hypertensive patients. A machine learning support vector machine (SVM) model including clinical risk factors (sex, BMI, alcohol use, current smoker, and hypertension family history), miR-361-3p, and miR-501-5p was able to classify hypertension patients in a test dataset with an AUC of 0.90, a balanced accuracy of 0.87, a sensitivity of 0.83, and a specificity of 0.91. While five miRNAs exhibited substantial downregulation in hypertension patients, only miR-361-3p and miR-501-5p, alongside clinical risk factors, were consistently chosen in at least eight out of ten sub-training sets within the SVM model.

CONCLUSIONS

This study highlights the potential significance of miRNA-based biomarkers in deepening our understanding of hypertension's pathophysiology and in personalizing treatment strategies. The strong performance of the SVM model highlights its potential as a valuable asset for diagnosing and managing essential hypertension. The model remains to be extensively validated in independent patient cohorts before evaluating its added value in a clinical setting.

Extracellular Vesicles in Pulmonary Hypertension: A Dangerous Liaison?

The term pulmonary hypertension (PH) refers to different conditions, all characterized by increased pressure and resistance in the pulmonary arterial bed. PH has a wide range of causes (essentially, cardiovascular, pulmonary, or connective tissue disorders); however, idiopathic (i.e., without a clear cause) PH exists. This chronic, progressive, and sometimes devastating disease can finally lead to right heart failure and eventually death, through pulmonary vascular remodeling and dysfunction. The exact nature of PH pathophysiology is sometimes still unclear. Extracellular vesicles (EVs), previously known as apoptotic bodies, microvesicles, and exosomes, are small membrane-bound vesicles that are generated by almost all cell types and can be detected in a variety of physiological fluids. EVs are involved in intercellular communication, thus influencing immunological response, inflammation, embryogenesis, aging, and regenerative processes. Indeed, they transport chemokines, cytokines, lipids, RNA and miRNA, and other biologically active molecules. Although the precise functions of EVs are still not fully known, there is mounting evidence that they can play a significant role in the pathophysiology of PH. In this review, after briefly recapping the key stages of PH pathogenesis, we discuss the current evidence on the functions of EVs both as PH biomarkers and potential participants in the distinct pathways of disease progression.

Emerging role of exosomes in vascular diseases

Exosomes are biological small spherical lipid bilayer vesicles secreted by most cells in the body. Their contents include nucleic acids, proteins, and lipids. Exosomes can transfer material molecules between cells and consequently have a variety of biological functions, participating in disease development while exhibiting potential value as biomarkers and therapeutics. Growing evidence suggests that exosomes are vital mediators of vascular remodeling. Endothelial cells (ECs), vascular smooth muscle cells (VSMCs), inflammatory cells, and adventitial fibroblasts (AFs) can communicate through exosomes; such communication is associated with inflammatory responses, cell migration and proliferation, and cell metabolism, leading to changes in vascular function and structure. Essential hypertension (EH), atherosclerosis (AS), and pulmonary arterial hypertension (PAH) are the most common vascular diseases and are associated with significant vascular remodeling. This paper reviews the latest research progress on the involvement of exosomes in vascular remodeling through intercellular information exchange and provides new ideas for understanding related diseases.

Current challenges and future directions for engineering extracellular vesicles for heart, lung, blood and sleep diseases

Extracellular vesicles (EVs) carry diverse bioactive components including nucleic acids, proteins, lipids and metabolites that play versatile roles in intercellular and interorgan communication. The capability to modulate their stability, tissue-specific targeting and cargo render EVs as promising nanotherapeutics for treating heart, lung, blood and sleep (HLBS) diseases. However, current limitations in large-scale manufacturing of therapeutic-grade EVs, and knowledge gaps in EV biogenesis and heterogeneity pose significant challenges in their clinical application as diagnostics or therapeutics for HLBS diseases. To address these challenges, a strategic workshop with multidisciplinary experts in EV biology and U.S. Food and Drug Administration (USFDA) officials was convened by the National Heart, Lung and Blood Institute. The presentations and discussions were focused on summarizing the current state of science and technology for engineering therapeutic EVs for HLBS diseases, identifying critical knowledge gaps and regulatory challenges and suggesting potential solutions to promulgate translation of therapeutic EVs to the clinic. Benchmarks to meet the critical quality attributes set by the USFDA for other cell-based therapeutics were discussed. Development of novel strategies and approaches for scaling-up EV production and the quality control/quality analysis (QC/QA) of EV-based therapeutics were recognized as the necessary milestones for future investigations.

MicroRNA-212-5p, an anti-proliferative miRNA, attenuates hypoxia and sugen/hypoxia-induced pulmonary hypertension in rodents

MicroRNAs (miRNA, miR-) play important roles in disease development. In this study, we identified an anti-proliferative miRNA, miR-212-5p, that is induced in pulmonary artery smooth muscle cells (PASMCs) and lungs of pulmonary hypertension (PH) patients and rodents with experimental PH. We found that smooth muscle cell (SMC)-specific knockout of miR-212-5p exacerbated hypoxia-induced pulmonary vascular remodeling and PH in mice, suggesting that miR-212-5p may be upregulated in PASMCs to act as an endogenous inhibitor of PH, possibly by suppressing PASMC proliferation. Extracellular vesicles (EVs) have been shown recently to be promising drug delivery tools for disease treatment. We generated endothelium-derived EVs with an enriched miR-212-5p load, 212-eEVs, and found that they significantly attenuated hypoxia-induced PH in mice and Sugen/hypoxia-induced severe PH in rats, providing proof of concept that engineered endothelium-derived EVs can be used to deliver miRNA into lungs for treatment of severe PH.