Extracellular Vesicles Mediate Communication between Endothelial and Vascular Smooth Muscle Cells

Proteomic analysis of endothelial cells and extracellular vesicles in response to indoxyl sulfate: Mechanisms of endothelial dysfunction in chronic kidney disease

AIMS

Cardiovascular pathology is the main cause of death in chronic kidney disease (CKD) patients. CKD is associated with the accumulation of uremic toxins in the bloodstream, and indoxyl sulfate (IS) is one of the most abundant uremic toxins found in the blood of CKD patients. We conducted an in vitro study to assess the mechanisms underlying the IS-induced endothelial dysfunction that could lead to cardiovascular diseases. We also studied their extracellular vesicles (EVs) owing to their capacity to act as messengers that transmit signals through their cargo.

MAIN METHODS

EVs were characterized by nanoparticle tracking analysis, transmission electron microscopy, flow cytometry, and tetraspanin expression. Cell lysates and isolated EVs were analyzed using liquid chromatography coupled with mass spectrometry, followed by Gene Set Enrichment Analysis to identify the altered pathways.

KEY FINDINGS

Proteomic analysis of endothelial cells revealed that IS causes an increase in proteins related to adipogenesis, inflammation, and xenobiotic metabolism and a decrease in proliferation. Extracellular matrix elements, as well as proteins associated with myogenesis, response to UV irradiation, and inflammation, were found to be downregulated in IS-treated EVs. Fatty acid metabolism was also found to be increased along with adipogenesis and inflammation observed in cells.

SIGNIFICANCE

The treatment of endothelial cells with IS increased the expression of proteins related to adipogenesis, inflammation, and xenobiotic metabolism and was less associated with proliferation. Furthermore, EVs from cells treated with IS may mediate endothelial dysfunction, since they present fewer extracellular matrix elements, myogenesis, inflammatory factors, and proteins downregulated in response to UV radiation.

The prognostic potential of long noncoding RNA XIST in cardiovascular diseases: a review

There is a significant mortality rate associated with cardiovascular disease despite advances in treatment. long Non-coding RNAs (lncRNAs) play a critical role in many biological processes and their dysregulation is associated with a wide range of diseases in which their downstream pathways are disrupted. A lncRNA X-inactive specific transcript (XIST) is well known as a factor that regulates the physiological process of chromosome dosage compensation for females. According to recent studies, lncRNA XIST is involved in a variety of cellular processes, including apoptosis, proliferation, invasion, metastasis, oxidative stress and inflammation, through molecular networks with microRNAs and their downstream targets in neoplastic and non-neoplastic diseases. Because these cellular processes play a role in the pathogenesis of cardiovascular diseases, we aim to investigate the role that lncRNA XIST plays in this process. Additionally, we wish to determine whether it is a prognostic factor or a potential therapeutic target in these diseases.

A 3D Bioprinted Human Neurovascular Unit Model of Glioblastoma Tumor Growth

A 3D bioprinted neurovascular unit (NVU) model is developed to study glioblastoma (GBM) tumor growth in a brain-like microenvironment. The NVU model includes human primary astrocytes, pericytes and brain microvascular endothelial cells, and patient-derived glioblastoma cells (JHH-520) are used for this study. Fluorescence reporters are used with confocal high content imaging to quantitate real-time microvascular network formation and tumor growth. Extensive validation of the NVU-GBM model includes immunostaining for brain relevant cellular markers and extracellular matrix components; single cell RNA sequencing (scRNAseq) to establish physiologically relevant transcriptomics changes; and secretion of NVU and GBM-relevant cytokines. The scRNAseq reveals changes in gene expression and cytokines secretion associated with wound healing/angiogenesis, including the appearance of an endothelial mesenchymal transition cell population. The NVU-GBM model is used to test 18 chemotherapeutics and anti-cancer drugs to assess the pharmacological relevance of the model and robustness for high throughput screening.

Elucidating VSMC phenotypic transition mechanisms to bridge insights into cardiovascular disease implications

Cardiovascular diseases (CVD) are the leading cause of death worldwide, despite advances in understanding cardiovascular health. Significant barriers still exist in effectively preventing and managing these diseases. Vascular smooth muscle cells (VSMCs) are crucial for maintaining vascular integrity and can switch between contractile and synthetic functions in response to stimuli such as hypoxia and inflammation. These transformations play a pivotal role in the progression of cardiovascular diseases, facilitating vascular modifications and disease advancement. This article synthesizes the current understanding of the mechanisms and signaling pathways regulating VSMC phenotypic transitions, highlighting their potential as therapeutic targets in cardiovascular disease interventions.

Communication between nonalcoholic fatty liver disease and atherosclerosis: Focusing on exosomes

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic hepatic disorder on a global scale. Atherosclerosis (AS), a leading cause of cardiovascular diseases, stands as the primary contributor to mortality among patients diagnosed with NAFLD. However, the precise etiology by which NAFLD causes AS remains unclear. Exosomes are nanoscale extracellular vesicles secreted by cells, and are considered to participate in complex biological processes by promoting cell-to-cell and organ-to-organ communications. As vesicles containing protein, mRNA, non-coding RNA and other bioactive molecules, exosomes can participate in the development of NAFLD and AS respectively. Recently, studies have shown that NAFLD can also promote the development of AS via secreting exosomes. Herein, we summarized the recent advantages of exosomes in the pathogenesis of NAFLD and AS, and highlighted the role of exosomes in mediating the information exchange between NAFLD and AS. Further, we discussed how exosomes play a prominent role in enabling information exchange among diverse organs, delving into a novel avenue for investigating the link between diseases and their associated complications. The future directions and emerging challenges are also listed regarding the exosome-based therapeutic strategies for AS under NAFLD conditions.

Extracellular Vesicles' Role in Angiogenesis and Altering Angiogenic Signaling

Angiogenesis, the process of new blood vessels formation from existing vasculature, plays a vital role in development, wound healing, and various pathophysiological conditions. In recent years, extracellular vesicles (EVs) have emerged as crucial mediators in intercellular communication and have gained significant attention for their role in modulating angiogenic processes. This review explores the multifaceted role of EVs in angiogenesis and their capacity to modulate angiogenic signaling pathways. Through comprehensive analysis of a vast body of literature, this review highlights the potential of utilizing EVs as therapeutic tools to modulate angiogenesis for both physiological and pathological purposes. A good understanding of these concepts holds promise for the development of novel therapeutic interventions targeting angiogenesis-related disorders.

Vascular Smooth Muscle TRPV4 (Transient Receptor Potential Vanilloid Family Member 4) Channels Regulate Vasoconstriction and Blood Pressure in Obesity

BACKGROUND

Vascular endothelium and smooth muscle work together to keep the balance of vasomotor tone and jointly maintain vascular homeostasis. Ca²⁺-permeable ion channel TRPV4 (transient receptor potential vanilloid family member 4) in endothelial cells regulates endothelium-dependent vasodilation and contraction in various states. However, how vascular smooth muscle cell TRPV4 (TRPV4_SMC) contributes to vascular function and blood pressure regulation in physiological and pathologically obese condition has not been fully studied.

METHODS

We generated smooth muscle TRPV4-deficient mice and developed diet-induced obese mice model and analyzed the role of TRPV4_SMC in intracellular Ca²⁺ ([Ca²⁺]_i) regulation and vasoconstriction. Vasomotor changes of mouse mesenteric artery were measured by wire, and pressure myography. [Ca²⁺]_i were measured by fluo-4 staining. Blood pressure was recorded by telemetric device.

RESULTS

Vascular TRPV4_SMC played different roles in regulating vasomotor tone than endothelial TRPV4 due to their different features of [Ca²⁺]_i regulation. Loss of TRPV4_SMC attenuated U46619- and phenylephrine-induced contraction, suggesting its involvement in regulating vascular contractility. Mesenteric arteries from obese mice showed SMC hyperplasia, suggesting an increased level of TRPV4_SMC. Loss of TRPV4_SMC did not influence the development of obesity but protected mice from obesity-induced vasoconstriction and hypertension. In arteries deficient in SMC TRPV4, SMCs F-actin polymerization and RhoA dephosphorylation were attenuated under contractile stimuli. Moreover, SMC-dependent vasoconstriction was inhibited in human resistance arteries with TRPV4 inhibitor application.

CONCLUSIONS

Our data identify TRPV4_SMC as a regulator of vascular contraction in both physiological states and pathologically obese mice. TRPV4_SMC contributes to the ontogeny of vasoconstriction and hypertension induced by TRPV4_SMC over-expression in obese mice mesenteric artery.

Updated Perspectives on Direct Vascular Cellular Reprogramming and Their Potential Applications in Tissue Engineered Vascular Grafts

Cardiovascular disease is a globally prevalent disease with far-reaching medical and socio-economic consequences. Although improvements in treatment pathways and revascularisation therapies have slowed disease progression, contemporary management fails to modulate the underlying atherosclerotic process and sustainably replace damaged arterial tissue. Direct cellular reprogramming is a rapidly evolving and innovative tissue regenerative approach that holds promise to restore functional vasculature and restore blood perfusion. The approach utilises cell plasticity to directly convert somatic cells to another cell fate without a pluripotent stage. In this narrative literature review, we comprehensively analyse and compare direct reprogramming protocols to generate endothelial cells, vascular smooth muscle cells and vascular progenitors. Specifically, we carefully examine the reprogramming factors, their molecular mechanisms, conversion efficacies and therapeutic benefits for each induced vascular cell. Attention is given to the application of these novel approaches with tissue engineered vascular grafts as a therapeutic and disease-modelling platform for cardiovascular diseases. We conclude with a discussion on the ethics of direct reprogramming, its current challenges, and future perspectives.

Endothelial-Smooth Muscle Cell Interactions in a Shear-Exposed Intimal Hyperplasia on-a-Dish Model to Evaluate Therapeutic Strategies

Intimal hyperplasia (IH) represents a major challenge following cardiovascular interventions. While mechanisms are poorly understood, the inefficient preventive methods incentivize the search for novel therapies. A vessel-on-a-dish platform is presented, consisting of direct-contact cocultures with human primary endothelial cells (ECs) and smooth muscle cells (SMCs) exposed to both laminar pulsatile and disturbed flow on an orbital shaker. With contractile SMCs sitting below a confluent EC layer, a model that successfully replicates the architecture of a quiescent vessel wall is created. In the novel IH model, ECs are seeded on synthetic SMCs at low density, mimicking reendothelization after vascular injury. Over 3 days of coculture, ECs transition from a network conformation to confluent 2D islands, as promoted by pulsatile flow, resulting in a "defected" EC monolayer. In defected regions, SMCs incorporated plasma fibronectin into fibers, increased proliferation, and formed multilayers, similarly to IH in vivo. These phenomena are inhibited under confluent EC layers, supporting therapeutic approaches that focus on endothelial regeneration rather than inhibiting proliferation, as illustrated in a proof-of-concept experiment with Paclitaxel. Thus, this in vitro system offers a new tool to study EC-SMC communication in IH pathophysiology, while providing an easy-to-use translational disease model platform for low-cost and high-content therapeutic development.

Recent advances of natural and bioengineered extracellular vesicles and their application in vascular regeneration

The progression of cardiovascular diseases such as atherosclerosis and myocardial infarction leads to serious vascular injury, highlighting the urgent need for targeted regenerative therapy. Extracellular vesicles (EVs) composed of a lipid bilayer containing nuclear and cytosolic materials are relevant to the progression of cardiovascular diseases. Moreover, EVs can deliver bioactive cargo in pathological cardiovascular and regulate the biological function of recipient cells, such as inflammation, proliferation, angiogenesis and polarization. However, because the targeting and bioactivity of natural EVs are subject to several limitations, bioengineered EVs have achieved wide advancements in biomedicine. Bioengineered EVs involve three main ways to acquire including (i) modification of the EVs after isolation; (ii) modification of producer cells before EVs’ isolation; (iii) synthesize EVs using natural or modified cell membranes, and encapsulating drugs or bioactive molecules into EVs. In this review, we first summarize the cardiovascular injury-related disease and describe the role of different cells and EVs in vascular regeneration. We also discuss the application of bioengineered EVs from different producer cells to cardiovascular diseases. Finally, we summarize the surface modification on EVs which can specifically target abnormal cells in injured vascular.

BRAFV600E Induction in Thyrocytes Triggers Important Changes in the miRNAs Content and the Populations of Extracellular Vesicles Released in Thyroid Tumor Microenvironment

Papillary thyroid cancer (PTC) is the most common endocrine malignancy for which diagnosis and recurrences still challenge clinicians. New perspectives to overcome these issues could come from the study of extracellular vesicle (EV) populations and content. Here, we aimed to elucidate the heterogeneity of EVs circulating in the tumor and the changes in their microRNA content during cancer progression. Using a mouse model expressing BRAF^V600E, we isolated and characterized EVs from thyroid tissue by ultracentrifugations and elucidated their microRNA content by small RNA sequencing. The cellular origin of EVs was investigated by ExoView and that of deregulated EV-microRNA by qPCR on FACS-sorted cell populations. We found that PTC released more EVs bearing epithelial and immune markers, as compared to the healthy thyroid, so that changes in EV-microRNAs abundance were mainly due to their deregulated expression in thyrocytes. Altogether, our work provides a full description of in vivo-derived EVs produced by, and within, normal and cancerous thyroid. We elucidated the global EV-microRNAs signature, the dynamic loading of microRNAs in EVs upon BRAF^V600E induction, and their cellular origin. Finally, we propose that thyroid tumor-derived EV-microRNAs could support the establishment of a permissive immune microenvironment.

A miRNA cassette reprograms smooth muscle cells into endothelial cells

Cellular reprogramming through targeting microRNAs (miRNAs) holds promise for regenerative therapy due to their profound regulatory effects in proliferation, differentiation, and function. We hypothesized that transdifferentiation of vascular smooth muscle cells (SMCs) into endothelial cells (ECs) using a miRNA cassette may provide a novel approach for use in vascular disease states associated with endothelial injury or dysfunction. miRNA profiling of SMCs and ECs and iterative combinatorial miRNA transfections of human coronary SMCs revealed a 4-miRNA cassette consisting of miR-143-3p and miR-145-5p inhibitors and miR-146a-5p and miR-181b-5p mimics that efficiently produced induced endothelial cells (iECs). Transcriptome profiling, protein expression, and functional studies demonstrated that iECs exhibit high similarity to ECs. Injected iECs restored blood flow recovery even faster than conventional ECs in a murine hindlimb ischemia model. This study demonstrates that a 4-miRNA cassette is sufficient to reprogram SMCs into ECs and shows promise as a novel regenerative strategy for endothelial repair.