Fibronectin on the Surface of Extracellular Vesicles Mediates Fibroblast Invasion

Cellular senescence in cancer: molecular mechanisms and therapeutic targets

Aging exhibits several hallmarks in common with cancer, such as cellular senescence, dysbiosis, inflammation, genomic instability, and epigenetic changes. In recent decades, research into the role of cellular senescence on tumor progression has received widespread attention. While how senescence limits the course of cancer is well established, senescence has also been found to promote certain malignant phenotypes. The tumor-promoting effect of senescence is mainly elicited by a senescence-associated secretory phenotype, which facilitates the interaction of senescent tumor cells with their surroundings. Targeting senescent cells therefore offers a promising technique for cancer therapy. Drugs that pharmacologically restore the normal function of senescent cells or eliminate them would assist in reestablishing homeostasis of cell signaling. Here, we describe cell senescence, its occurrence, phenotype, and impact on tumor biology. A "one-two-punch" therapeutic strategy in which cancer cell senescence is first induced, followed by the use of senotherapeutics for eliminating the senescent cells is introduced. The advances in the application of senotherapeutics for targeting senescent cells to assist cancer treatment are outlined, with an emphasis on drug categories, and the strategies for their screening, design, and efficient targeting. This work will foster a thorough comprehension and encourage additional research within this field.

Decrease of exosomal miR-21-5p and the increase of CD62p+ exosomes are associated with the development of sepsis in polytraumatized patients

Sepsis as a severe systemic inflammation leads oftentimes to organ dysfunction and subsequently to death. In polytrauma patients, septic complications represent with 45% the predominant cause of late death and are responsible for extremely high costs in the healthcare system. Therefore, clinicians have to detect as early as possible the begin of sepsis to improve the patient's outcome. One new promising diagnostic tool to diagnose septic complications in polytraumatized patients are exosomes. Plasma samples from polytraumatized patients (Injury Severity Score (ISS) ≥16) which developed sepsis (n = 10) and without sepsis (n = 10), were collected at emergency room (ER), 24h and 5 days after trauma. The EVs subpopulations were investigated by a bead-based multiplex flow cytometry measurement of surface epitopes and were compared with plasma EVs from healthy controls (n = 10). Moreover, exosomal cytokine concentrations were measured via high-sensitive ELISA and were correlated with systemic concentrations. For miRNA cargo analysis, we analysed the miRNAs miR-1298-5p, miR-1262, miR-125b-5p, miR-92a-3p, miR-93-5p, miR-155-5p and miR-21-5p and compared their exosomal concentrations by means of RT-qPCR. CD62p + exosomes were significantly increased in septic polytrauma-patients (p ≤ 0.05), while CD40+exosomes, as well as CD49e + exosomes were diminished (p ≤ 0.05). Furthermore, we observed that the exosomal IL-6 concentration reflects the systemic IL-6 concentration (r2 = 0.63) and did not significantly alter between patients with and without sepsis. The exosomal IL-10 concentration seemed to be constant in all patients and healthy controls. We observed that a decrease of miR-21-5p in exosomes was associated with the development of sepsis (p ≤ 0.05), while exosomal miR-93-5p, miR-155-5p and miR-92a-3p were not specifically altered in septic patients. Taken together, the present study in polytraumatized patients demonstrated that the development of sepsis is associated with an increase of CD62p + exosomes. Furthermore, the exosomal cargo was changed in septic patients: miR-21-5p was diminished.

The role of fibronectin in mediating cell migration

Fibronectin (FN) is a major extracellular matrix (ECM) protein involved in a wide range of physiological processes, including cell migration. These FN-mediated cell migration events are essential to processes such as wound repair, cancer metastasis, and vertebrate development. This review synthesizes mainly current literature to provide an overview of the mechanoregulatory role of FN-mediated cell migration. Background on FN structure and role in mechanotransduction is provided. Cell migration concepts are introduced, including the general cell migration mechanism and classification of cell migration types. Then, FN-mediated events that directly affect cell migration are explored. Finally, a focus on FN in tissue repair and cancer migration is presented, as these topics represent a large amount of current research.

Matrimeres are systemic nanoscale mediators of tissue integrity and function

Tissue barriers must be rapidly restored after injury to promote regeneration. However, the mechanism behind this process is unclear, particularly in cases where the underlying extracellular matrix is still compromised. Here, we report the discovery of matrimeres as constitutive nanoscale mediators of tissue integrity and function. We define matrimeres as non-vesicular nanoparticles secreted by cells, distinguished by a primary composition comprising at least one matrix protein and DNA molecules serving as scaffolds. Mesenchymal stromal cells assemble matrimeres from fibronectin and DNA within acidic intracellular compartments. Drawing inspiration from this biological process, we have achieved the successful reconstitution of matrimeres without cells. This was accomplished by using purified matrix proteins, including fibronectin and vitronectin, and DNA molecules under optimal acidic pH conditions, guided by the heparin-binding domain and phosphate backbone, respectively. Plasma fibronectin matrimeres circulate in the blood at homeostasis but exhibit a 10-fold decrease during systemic inflammatory injury in vivo . Exogenous matrimeres rapidly restore vascular integrity by actively reannealing endothelial cells post-injury and remain persistent in the host tissue matrix. The scalable production of matrimeres holds promise as a biologically inspired platform for regenerative nanomedicine.

Proteolytic Vesicles Derived from Salmonella enterica Serovar Typhimurium-Infected Macrophages: Enhancing MMP-9-Mediated Invasion and EV Accumulation

Proteolysis of the extracellular matrix (ECM) by matrix metalloproteinases (MMPs) plays a crucial role in the immune response to bacterial infections. Here we report the secretion of MMPs associated with proteolytic extracellular vesicles (EVs) released by macrophages in response to Salmonella enterica serovar Typhimurium infection. Specifically, we used global proteomics, in vitro, and in vivo approaches to investigate the composition and function of these proteolytic EVs. Using a model of S. Typhimurium infection in murine macrophages, we isolated and characterized a population of small EVs. Bulk proteomics analysis revealed significant changes in protein cargo of naïve and S. Typhimurium-infected macrophage-derived EVs, including the upregulation of MMP-9. The increased levels of MMP-9 observed in immune cells exposed to S. Typhimurium were found to be regulated by the toll-like receptor 4 (TLR-4)-mediated response to bacterial lipopolysaccharide. Macrophage-derived EV-associated MMP-9 enhanced the macrophage invasion through Matrigel as selective inhibition of MMP-9 reduced macrophage invasion. Systemic administration of fluorescently labeled EVs into immunocompromised mice demonstrated that EV-associated MMP activity facilitated increased accumulation of EVs in spleen and liver tissues. This study suggests that macrophages secrete proteolytic EVs to enhance invasion and ECM remodeling during bacterial infections, shedding light on an essential aspect of the immune response.

Characterisation of Matrix-Bound Nanovesicles (MBVs) Isolated from Decellularised Bovine Pericardium: New Frontiers in Regenerative Medicine

Matrix-bound nanovesicles (MBVs) are a recently discovered type of extracellular vesicles (EVs), and they are characterised by a strong adhesion to extracellular matrix structural proteins (ECM) and ECM-derived biomaterials. MBVs contain a highly bioactive and tissue-specific cargo that recapitulates the biological activity of the source ECM. The rich content of MBVs has shown to be capable of potent cell signalling and of modulating the immune system, thus the raising interest for their application in regenerative medicine. Given the tissue-specificity and the youthfulness of research on MBVs, until now they have only been isolated from a few ECM sources. Therefore, the objective of this research was to isolate and identify the presence of MBVs in decellularised bovine pericardium ECM and to characterise their protein content, which is expected to play a major role in their biological potential. The results showed that nanovesicles, corresponding to the definition of recently described MBVs, could be isolated from decellularised bovine pericardium ECM. Moreover, these MBVs were composed of numerous proteins and cytokines, thus preserving a highly potential biological effect. Overall, this research shows that bovine pericardium MBVs show a rich and tissue-specific biological potential.

Entry and exit of extracellular vesicles to and from the blood circulation

Extracellular vesicles (EVs) are biological nanoparticles that promote intercellular communication by delivering bioactive cargo over short and long distances. Short-distance communication takes place in the interstitium, whereas long-distance communication is thought to require transport through the blood circulation to reach distal sites. Extracellular vesicle therapeutics are frequently injected systemically, and diagnostic approaches often rely on the detection of organ-derived EVs in the blood. However, the mechanisms by which EVs enter and exit the circulation are poorly understood. Here, the lymphatic system and transport across the endothelial barrier through paracellular and transcellular routes are discussed as potential pathways for EV entry to and exit from the blood circulatory system.

Role of Extracellular Vesicles in the Propagation of Lung Fibrosis in Systemic Sclerosis

OBJECTIVES

Systemic sclerosis (SSc) has the highest mortality rate among the rheumatic diseases, with lung fibrosis leading as the cause of death. A characteristic of severe SSc-related lung fibrosis is its progressive nature. Although most research has focused on the pathology of the fibrosis, the mechanism mediating the fibrotic spread remains unclear. We hypothesized that extracellular vesicle (EV) communication drives the propagation of SSc lung fibrosis.

METHODS

EVs were isolated from normal (NL) or SSc-derived human lungs and primary lung fibroblasts (pLFs). EVs were also isolated from human fibrotic lungs and pLFs induced experimentally with transforming growth factor-β (TGFβ). Fibrotic potency of EVs was assessed using functional assays in vitro and in vivo. Transmission electron microscopy, nanoparticle tracking analysis, real-time quantitative polymerase chain reaction (RT-qPCR), immunoblotting, and immunofluorescence were used to analyze EVs, their cargo, extracellular matrix (ECM) fractions, and conditioned media.

RESULTS

SSc lungs and pLFs released significantly more EVs than NL lungs, and their EVs showed increased fibrotic content and activity. TGFβ-stimulated NL lung cores and pLFs increased packaging of fibrotic proteins, including fibronectin, collagens, and TGFβ, into released EVs. The EVs induced a fibrotic phenotype in recipient pLFs and in vivo in mouse lungs. Furthermore, EVs interacted with and contributed to the ECM. Finally, suppressing EV release in vivo reduced severity of murine lung fibrosis.

CONCLUSIONS

Our findings highlight EV communication as a novel mechanism for propagation of SSc lung fibrosis. Identifying therapies that reduce EV release, activity, and/or fibrotic cargo in SSc patient lungs may be a viable therapeutic strategy to improve fibrosis.

Identification of Hub Genes in Idiopathic Pulmonary Fibrosis and Their Association with Lung Cancer by Bioinformatics Analysis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and irreversible disease with a high mortality rate worldwide. However, the etiology and pathogenesis of IPF have not yet been fully described. Moreover, lung cancer is a significant complication of IPF and is associated with increased mortality. Nevertheless, identifying common genes involved in developing IPF and its progression to lung cancer remains an unmet need. The present study aimed to identify hub genes related to the development of IPF by meta-analysis. In addition, we analyzed their expression and their relationship with patients' progression in lung cancer.

METHOD

Microarray datasets GSE24206, GSE21369, GSE110147, GSE72073, and GSE32539 were downloaded from Gene Expression Omnibus (GEO). Next, we conducted a series of bioinformatics analysis to explore possible hub genes in IPF and evaluated the expression of hub genes in lung cancer and their relationship with the progression of different stages of cancer.

RESULTS

A total of 1888 differentially expressed genes (DEGs) were identified, including 1105 upregulated and 783 downregulated genes. The 10 hub genes that exhibited a high degree of connectivity from the PPI network were identified. Analysis of the KEGG pathways showed that hub genes correlate with pathways such as the ECM-receptor interaction. Finally, we found that these hub genes are expressed in lung cancer and are associated with the progression of different stages of lung cancer.

CONCLUSIONS

Based on the integration of GEO microarray datasets, the present study identified DEGs and hub genes that could play an essential role in the pathogenesis of IPF and its association with the development of lung cancer in these patients, which could be considered potential diagnostic biomarkers or therapeutic targets for the disease.

Fibroblast-derived Extracellular Vesicles Induce Lung Cancer Progression in the Idiopathic Pulmonary Fibrosis Microenvironment

Idiopathic pulmonary fibrosis (IPF) is a progressive aging-related lung disease associated with increased lung cancer risk. Although previous studies have shown that IPF worsens the survival of patients with lung cancer, whether IPF independently affects cancer malignancy and prognosis remains inconclusive. Extracellular vesicles (EVs) have recently emerged as active carriers of molecular biomarkers and mediators of intercellular communication in lung homeostasis and pathogenesis. EV cargo-mediated fibroblast-tumor cell communication might participate in the development and progression of lung cancer by modulating various signaling pathways. In this study, we examined the impact of lung fibroblast (LF)-derived EVs on non-small cell lung cancer (NSCLC) malignancy in the IPF microenvironment. Here, we showed that LFs derived from patients with IPF have phenotypes of myofibroblast differentiation and cellular senescence. Furthermore, we found that IPF LF-derived EVs have markedly altered microRNA compositions and exert proproliferative functions on NSCLC cells. Mechanistically, the phenotype was attributed mainly to the enrichment of miR-19a in IPF LF-derived EVs. As a downstream signaling pathway, mir-19a in IPF LF-derived EVs regulates ZMYND11-mediated c-Myc activation in NSCLC, potentially contributing to the poor prognosis of patients with NSCLC with IPF. Our discoveries provide novel mechanistic insights for understanding lung cancer progression in the IPF microenvironment. Accordingly, blocking the secretion of IPF LF-derived EV miR-19a and their signaling pathways is a potential therapeutic strategy for managing IPF and lung cancer progression.

Manufacture of extracellular vesicles derived from mesenchymal stromal cells

Mesenchymal stromal cells (MSCs) are a promising therapy for various diseases ranging from ischemic stroke to wound healing and cancer. Their therapeutic effects are mainly mediated by secretome-derived paracrine factors, with extracellular vesicles (EVs) proven to play a key role. This has led to promising research on the potential of MSC-EVs as regenerative, off-the-shelf therapeutic agents. However, the translation of MSC-EVs into the clinic is hampered by the poor scalability of their production. Recently, new advanced methods have been developed to upscale MSC cultivation and EV production yields, ranging from new cell culture devices to priming procedures. This review gives an overview of these innovative strategies for manufacturing MSC-EVs.

Extracellular Vesicles as "Very Important Particles" (VIPs) in Aging

In recent decades, extracellular vesicles have been recognized as "very important particles" (VIPs) associated with aging and age-related disease. During the 1980s, researchers discovered that these vesicle particles released by cells were not debris but signaling molecules carrying cargoes that play key roles in physiological processes and physiopathological modulation. Following the International Society for Extracellular Vesicles (ISEV) recommendation, different vesicle particles (e.g., exosomes, microvesicles, oncosomes) have been named globally extracellular vesicles. These vesicles are essential to maintain body homeostasis owing to their essential and evolutionarily conserved role in cellular communication and interaction with different tissues. Furthermore, recent studies have shown the role of extracellular vesicles in aging and age-associated diseases. This review summarizes the advances in the study of extracellular vesicles, mainly focusing on recently refined methods for their isolation and characterization. In addition, the role of extracellular vesicles in cell signaling and maintenance of homeostasis, as well as their usefulness as new biomarkers and therapeutic agents in aging and age-associated diseases, has also been highlighted.

Fibronectin and JMJD6 Signature in Circulating Placental Extracellular Vesicles for the Detection of Preeclampsia

Preeclampsia (PE) is a major obstetric complication that is challenging to predict. Currently, there are limited tools to assess placental health/function in crucial gestational periods for diagnosis and early prediction. The glycoprotein fibronectin (FN) is augmented in PE placentae, and associated with reduced activity of JMJD6, an oxygen sensor that regulates placental FN processing. Evidence implicates placenta-derived small extracellular vesicles (sEVs) in the pathogenesis of pregnancy-associated disorders. Here, we examined the utility of FN and JMJD6 in placental sEVs as putative markers for early- and late-onset PE (E-PE and L-PE). Maternal plasma was obtained from venous blood collected longitudinally during pregnancy (10-14, 16-22, and 26-32 weeks of gestation and at delivery) in normotensive term control, preterm control, L-PE, E-PE, and gestational hypertensive individuals. Placenta-derived sEVs were isolated and their FN and JMJD6 content and JMJD6 activity were measured. In women that went on to develop preeclampsia, FN content of circulating placental sEVs was significantly elevated as early as 10 to 14 weeks of gestation and remained augmented until the time of delivery. This was accompanied by a depletion in JMJD6 content. Multivariate receiver operating characteristic analysis revealed high predictive power for FN and JMJD6 as early markers of E-PE and L-PE. In vitro, hypoxia or JMJD6 loss promoted FN accumulation in sEVs that was reverted on restoring cellular iron balance with the natural compound, Hinokitiol. Elevated FN, along with diminished JMJD6 in circulating placental sEVs, serves as an early molecular signature for the detection of different hypertensive disorders of pregnancy and their severity.

Extracellular Vesicles in Aging: An Emerging Hallmark?

Extracellular vesicles (EVs) are membrane-enclosed particles secreted by cells and circulating in body fluids. Initially considered as a tool to dispose of unnecessary material, they are now considered an additional method to transmit cell signals. Aging is characterized by a progressive impairment of the physiological functions of tissues and organs. The causes of aging are complex and interconnected, but there is consensus that genomic instability, telomere erosion, epigenetic alteration, and defective proteostasis are primary hallmarks of the aging process. Recent studies have provided evidence that many of these primary stresses are associated with an increased release of EVs in cell models, able to spread senescence signals in the recipient cell. Additional investigations on the role of EVs during aging also demonstrated the great potential of EVs for the modulation of age-related phenotypes and for pro-rejuvenation therapies, potentially beneficial for many diseases associated with aging. Here we reviewed the current literature on EV secretion in senescent cell models and in old vs. young individual body fluids, as well as recent studies addressing the potential of EVs from different sources as an anti-aging tool. Although this is a recent field, the robust consensus on the altered EV release in aging suggests that altered EV secretion could be considered an emerging hallmark of aging.

Immune Mechanisms of Pulmonary Fibrosis with Bleomycin

Fibrosis and structural remodeling of the lung tissue can significantly impair lung function, often with fatal consequences. The etiology of pulmonary fibrosis (PF) is diverse and includes different triggers such as allergens, chemicals, radiation, and environmental particles. However, the cause of idiopathic PF (IPF), one of the most common forms of PF, remains unknown. Experimental models have been developed to study the mechanisms of PF, and the murine bleomycin (BLM) model has received the most attention. Epithelial injury, inflammation, epithelial-mesenchymal transition (EMT), myofibroblast activation, and repeated tissue injury are important initiators of fibrosis. In this review, we examined the common mechanisms of lung wound-healing responses after BLM-induced lung injury as well as the pathogenesis of the most common PF. A three-stage model of wound repair involving injury, inflammation, and repair is outlined. Dysregulation of one or more of these three phases has been reported in many cases of PF. We reviewed the literature investigating PF pathogenesis, and the role of cytokines, chemokines, growth factors, and matrix feeding in an animal model of BLM-induced PF.

Extracellular Vesicles and Cardiac Aging

Global population aging is a major challenge to health and socioeconomic policies. The prevalence of diseases progressively increases with aging, with cardiovascular disease being the major cause of mortality among elderly people. The allostatic overload imposed by the accumulation of cardiac senescent cells has been suggested to play a pivotal role in the aging-related deterioration of cardiovascular function. Senescent cells exhibit intrinsic disorders and release a senescence-associated secretory phenotype (SASP). Most of these SASP compounds and damaged molecules are released from senescent cells by extracellular vesicles (EVs). Once secreted, these EVs can be readily incorporated by recipient neighboring cells and elicit cellular damage or otherwise can promote extracellular matrix remodeling. This has been associated with the development of cardiac dysfunction, fibrosis, and vascular calcification, among others. The molecular signature of these EVs is highly variable and might provide important information for the development of aging-related biomarkers. Conversely, EVs released by the stem and progenitor cells can exert a rejuvenating effect, raising the possibility of future anti-aging therapies.

Cell-Matrix Interactions in Renal Fibrosis

Renal fibrosis is a hallmark of end-stage chronic kidney disease. It is characterized by increased accumulation of extracellular matrix (ECM), which disrupts cellular organization and function within the kidney. Here, we review the bi-directional interactions between cells and the ECM that drive renal fibrosis. We will discuss the cells involved in renal fibrosis, changes that occur in the ECM, the interactions between renal cells and the surrounding fibrotic microenvironment, and signal transduction pathways that are misregulated as fibrosis proceeds. Understanding the underlying mechanisms of cell-ECM crosstalk will identify novel targets to better identify and treat renal fibrosis and associated renal disease.

EVs-miRNA: The New Molecular Markers for Chronic Respiratory Diseases

Idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), asthma and sleep disorders are chronic respiratory diseases that affect the airways, compromising lung function over time. These diseases affect hundreds of millions of people around the world and their frequency seems to be increasing every year. Extracellular vesicles (EVs) are small-sized vesicles released by every cell in the body. They are present in most body fluids and contain various biomolecules including proteins, lipids, mRNA and non-coding RNA (micro-RNA). The EVs can release their cargo, specifically micro-RNAs (miRNAs), to both neighboring and/or distal cells, playing a fundamental role in cell-cell communication. Recent studies have shown their possible role in the pathogenesis of various chronic respiratory diseases. The expression of miRNAs and, in particular, of miRNAs contained within the extracellular vesicles seems to be a good starting point in order to identify new potential biomarkers of disease, allowing a non-invasive clinical diagnosis. In this review we summarize some studies, present in the literature, about the functions of extracellular vesicles and miRNAs contained in extracellular vesicles in chronic respiratory diseases and we discuss the potential clinical applications of EVs and EVs-miRNAs for their possible use such as future biomarkers.

Exosomal Micro-RNAs as Intercellular Communicators in Idiopathic Pulmonary Fibrosis

Communication between neighboring or distant cells is made through a complex network that includes extracellular vesicles (EVs). Exosomes, which are a subgroup of EVs, are released from most cell types and have been found in biological fluids such as urine, plasma, and airway secretions like bronchoalveolar lavage (BAL), nasal lavage, saliva, and sputum. Mainly, the cargo exosomes are enriched with mRNAs and microRNAs (miRNAs), which can be transferred to a recipient cell consequently modifying and redirecting its biological function. The effects of miRNAs derive from their role as gene expression regulators by repressing or degrading their target mRNAs. Nowadays, various types of research are focused on evaluating the potential of exosomal miRNAs as biomarkers for the prognosis and diagnosis of different pathologies. Nevertheless, there are few reports on their role in the pathophysiology of idiopathic pulmonary fibrosis (IPF), a chronic lung disease characterized by progressive lung scarring with no cure. In this review, we focus on the role and effect of exosomal miRNAs as intercellular communicators in the onset and progression of IPF, as well as discussing their potential utility as therapeutic agents for the treatment of this disease.

Novel mediators of idiopathic pulmonary fibrosis

Fibrosis involving the lung may occur in many settings, including in association with known environmental agents, connective tissue diseases, and exposure to drugs or radiation therapy. The most common form is referred to as 'idiopathic' since a causal agent or specific association has not been determined; the strongest risk factor for idiopathic pulmonary fibrosis is aging. Emerging studies indicate that targeting certain components of aging biology may be effective in mitigating age-associated fibrosis. While transforming growth factor-β1 (TGF-β1) is a central mediator of fibrosis in almost all contexts, and across multiple organs, it is not feasible to target this canonical pathway at the ligand-receptor level due to the pleiotropic nature of its actions; importantly, its homeostatic roles as a tumor-suppressor and immune-modulator make this an imprudent strategy. However, defining targets downstream of its receptor(s) that mediate fibrogenesis, while relatively dispenable for tumor- and immune-suppressive functions may aid in developing safer and more effective therapies. In this review, we explore molecular targets that, although TGF-β1 induced/activated, may be relatively more selective in mediating tissue fibrosis. Additionally, we explore epigenetic mechanisms with global effects on the fibrogenic process, as well as metabolic pathways that regulate aging and fibrosis.

Tumour Derived Extracellular Vesicles: Challenging Target to Blunt Tumour Immune Evasion

Simple Summary

Tumour onset and development occur because of specific immune support. The immune system, which is originally able to perceive and eliminate incipient cancer cells, becomes suppressed and hijacked by cancer. For these purposes, tumour cells use extracellular vesicles (TEVs). Specific molecular composition allows TEVs to reprogram immune cells towards tumour tolerance. Circulating TEVs move from their site of origin to other organs, preparing “a fertile soil” for metastasis formation. This implies that TEV molecular content can provide a valuable tool for cancer biomarker discovery and potential targets to reshape the immune system into tumour recognition and eradication.

Abstract

Control of the immune response is crucial for tumour onset and progression. Tumour cells handle the immune reaction by means of secreted factors and extracellular vesicles (EV). Tumour-derived extracellular vesicles (TEV) play key roles in immune reprogramming by delivering their cargo to different immune cells. Tumour-surrounding tissues also contribute to tumour immune editing and evasion, tumour progression, and drug resistance via locally released TEV. Moreover, the increase in circulating TEV has suggested their underpinning role in tumour dissemination. This review brings together data referring to TEV-driven immune regulation and antitumour immune suppression. Attention was also dedicated to TEV-mediated drug resistance.

Roles of exosomes and exosome-derived miRNAs in pulmonary fibrosis

Pulmonary fibrosis is a chronic, progressive fibrosing interstitial lung disease of unknown etiology that leads rapidly to death. It is characterized by the replacement of healthy tissue through an altered extracellular matrix and damage to the alveolar structure. New pharmacological treatments and biomarkers are needed for pulmonary fibrosis to ensure better outcomes and earlier diagnosis of patients. Exosomes are nanoscale vesicles released by nearly all cell types that play a central role as mediators of cell-to-cell communication. Moreover, exosomes are emerging as a crucial factor in antigen presentation, immune response, immunomodulation, inflammation, and cellular phenotypic transformation and have also shown promising therapeutic potential in pulmonary fibrosis. This review summarizes current knowledge of exosomes that may promote pulmonary fibrosis and be utilized for diagnostics and prognostics. In addition, the utilization of exosomes and their cargo miRNAs as novel therapeutics and their potential mechanisms are also discussed. This review aims to elucidate the role of exosomes in the pathogenesis of pulmonary fibrosis and paves the way for developing novel therapeutics for pulmonary fibrosis. Further in-depth research and clinical trials on this topic are encouraged in the future.

Role of extracellular vesicles in lung diseases

ABSTRACT

Extracellular vesicles (EVs) are anuclear particles composed of lipid bilayers that contain nucleic acids, proteins, lipids, and organelles. EVs act as an important mediator of cell-to-cell communication by transmitting biological signals or components, including lipids, proteins, messenger RNAs, DNA, microRNAs, organelles, etc, to nearby or distant target cells to activate and regulate the function and phenotype of target cells. Under physiological conditions, EVs play an essential role in maintaining the homeostasis of the pulmonary milieu but they can also be involved in promoting the pathogenesis and progression of various respiratory diseases including chronic obstructive pulmonary disease, asthma, acute lung injury/acute respiratory distress syndrome, idiopathic pulmonary fibrosis (IPF), and pulmonary artery hypertension. In addition, in multiple preclinical studies, EVs derived from mesenchymal stem cells (EVs) have shown promising therapeutic effects on reducing and repairing lung injuries. Furthermore, in recent years, researchers have explored different methods for modifying EVs or enhancing EVs-mediated drug delivery to produce more targeted and beneficial effects. This article will review the characteristics and biogenesis of EVs and their role in lung homeostasis and various acute and chronic lung diseases and the potential therapeutic application of EVs in the field of clinical medicine.

Extracellular vesicles in idiopathic pulmonary fibrosis: pathogenesis and therapeutics

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease that occurs due to increased fibrosis of lung tissue in response to chronic injury of the epithelium. Therapeutic options for IPF remain limited as current therapies only function to decrease disease progression. Recently, extracellular vesicles (EVs), including exosomes and microvesicles, have been recognized as paracrine communicators through the component cargo. The population of cell-specific microRNAs and proteins present in EVs can regulate gene expressions of recipient cells, resulting in modulation of biological activities. EV cargoes reflect cell types and their physiological and pathological status of donor cells. Many current researches have highlighted the functions of EVs on the epithelial phenotype and fibroproliferative response in the pathogenesis of IPF. Furthermore, some native EVs could be used as a cell-free therapeutic approach for IPF as vehicles for drug delivery, given their intrinsic biocompatibility and specific target activity. EV-based therapies have been proposed as a new potential alternative to cell-based approaches. The advantage is that EVs, depending on their source, may be less immunogenic than their parental cells, likely due to a lower abundance of transmembrane proteins such as major histocompatibility complex (MHC) proteins on the surface. In the last decade, mesenchymal stem cell (MSC)-derived EVs have been rapidly developed as therapeutic products ready for clinical trials against various diseases. Considering EV functional complexity and heterogeneity, there is an urgent need to establish refined systemic standards for manufacturing processes and regulatory requirements of these medicines. This review highlights the EV-mediated cellular crosstalk involved in IPF pathogenesis and discusses the potential for EV-based therapeutics as a novel treatment modality for IPF.

Role of MicroRNAs in Signaling Pathways Associated with the Pathogenesis of Idiopathic Pulmonary Fibrosis: A Focus on Epithelial-Mesenchymal Transition

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive disease with high mortality and unclear etiology. Previous evidence supports that the origin of this disease is associated with epigenetic alterations, age, and environmental factors. IPF initiates with chronic epithelial lung injuries, followed by basal membrane destruction, which promotes the activation of myofibroblasts and excessive synthesis of extracellular matrix (ECM) proteins, as well as epithelial-mesenchymal transition (EMT). Due to miRNAs’ role as regulators of apoptosis, proliferation, differentiation, and cell-cell interaction processes, some studies have involved miRNAs in the biogenesis and progression of IPF. In this context, the analysis and discussion of the probable association of miRNAs with the signaling pathways involved in the development of IPF would improve our knowledge of the associated molecular mechanisms, thereby facilitating its evaluation as a therapeutic target for this severe lung disease. In this work, the most recent publications evaluating the role of miRNAs as regulators or activators of signal pathways associated with the pathogenesis of IPF were analyzed. The search in Pubmed was made using the following terms: “miRNAs and idiopathic pulmonary fibrosis (IPF)”; “miRNAs and IPF and signaling pathways (SP)”; and “miRNAs and IPF and SP and IPF pathogenesis”. Additionally, we focus mainly on those works where the signaling pathways involved with EMT, fibroblast differentiation, and synthesis of ECM components were assessed. Finally, the importance and significance of miRNAs as potential therapeutic or diagnostic tools for the treatment of IPF are discussed.

Asthma and Post-Asthmatic Fibrosis: A Search for New Promising Molecular Markers of Transition from Acute Inflammation to Pulmonary Fibrosis

Asthma is a heterogeneous pulmonary disorder, the progression and chronization of which leads to airway remodeling and fibrogenesis. To understand the molecular mechanisms of pulmonary fibrosis development, key genes forming the asthma-specific regulome and involved in lung fibrosis formation were revealed using a comprehensive bioinformatics analysis. The bioinformatics data were validated using a murine model of ovalbumin (OVA)-induced asthma and post-asthmatic fibrosis. The performed analysis revealed a range of well-known pro-fibrotic markers (Cat, Ccl2, Ccl4, Ccr2, Col1a1, Cxcl12, Igf1, Muc5ac/Muc5b, Spp1, Timp1) and a set of novel genes (C3, C3ar1, Col4a1, Col4a2, Cyp2e1, Fn1, Thbs1, Tyrobp) mediating fibrotic changes in lungs already at the stage of acute/subacute asthma-driven inflammation. The validation of genes related to non-allergic bleomycin-induced pulmonary fibrosis on asthmatic/fibrotic lungs allowed us to identify new universal genes (Col4a1 and Col4a2) associated with the development of lung fibrosis regardless of its etiology. The similarities revealed in the expression profiles of nodal fibrotic genes between asthma-driven fibrosis in mice and nascent idiopathic pulmonary fibrosis in humans suggest a tight association of identified genes with the early stages of airway remodeling and can be considered as promising predictors and early markers of pulmonary fibrosis.

Insight into Extracellular Vesicle-Cell Communication: From Cell Recognition to Intracellular Fate

Extracellular vesicles (EVs) are heterogamous lipid bilayer-enclosed membranous structures secreted by cells. They are comprised of apoptotic bodies, microvesicles, and exosomes, and carry a range of nucleic acids and proteins that are necessary for cell-to-cell communication via interaction on the cells surface. They initiate intracellular signaling pathways or the transference of cargo molecules, which elicit pleiotropic responses in recipient cells in physiological processes, as well as pathological processes, such as cancer. It is therefore important to understand the molecular means by which EVs are taken up into cells. Accordingly, this review summarizes the underlying mechanisms involved in EV targeting and uptake. The primary method of entry by EVs appears to be endocytosis, where clathrin-mediated, caveolae-dependent, macropinocytotic, phagocytotic, and lipid raft-mediated uptake have been variously described as being prevalent. EV uptake mechanisms may depend on proteins and lipids found on the surfaces of both vesicles and target cells. As EVs have been shown to contribute to cancer growth and progression, further exploration and targeting of the gateways utilized by EVs to internalize into tumor cells may assist in the prevention or deceleration of cancer pathogenesis.

Extracellular Vesicles and Transforming Growth Factor β Signaling in Cancer

Complexity in mechanisms that drive cancer development and progression is exemplified by the transforming growth factor β (TGF-β) signaling pathway, which suppresses early-stage hyperplasia, yet assists aggressive tumors to achieve metastasis. Of note, several molecules, including mRNAs, non-coding RNAs, and proteins known to be associated with the TGF-β pathway have been reported as constituents in the cargo of extracellular vesicles (EVs). EVs are secreted vesicles delimited by a lipid bilayer and play critical functions in intercellular communication, including regulation of the tumor microenvironment and cancer development. Thus, this review aims at summarizing the impact of EVs on TGF-β signaling by focusing on mechanisms by which EV cargo can influence tumorigenesis, metastatic spread, immune evasion and response to anti-cancer treatment. Moreover, we emphasize the potential of TGF-β-related molecules present in circulating EVs as useful biomarkers of prognosis, diagnosis, and prediction of response to treatment in cancer patients.

Tackling the effects of extracellular vesicles in fibrosis

Fibrosis is a physiological process of tissue repair that turns into pathological when becomes chronic, damaging the functional structure of the tissue. In this review we outline the current status of extracellular vesicles as modulators of the fibrotic process at different levels. In adipose tissue, extracellular vesicles mediate the intercellular communication not only between adipocytes, but also between adipocytes and other cells of the stromal vascular fraction. Thus, they could be altering essential processes for the functionality of adipose tissue, such as adipocyte hypertrophy/hyperplasia, tissue plasticity, adipogenesis and/or inflammation, and ultimately trigger fibrosis. This process is particularly important in obesity, and may eventually, influence the development of obesity-associated alterations. In this regard, obesity is now recognized as an independent risk factor for the development of chronic kidney disease, although the role of extracellular vesicles in this connection has not been explored so far. Nonetheless, the role of extracellular vesicles in the onset and progression of renal fibrosis has been highlighted due to the critical role of fibrosis as a common feature of kidney diseases. In fact, the content of extracellular vesicles disturbs cellular signaling cascades involved in fibrosis in virtually all types of renal cells. What is certain is that the study of extracellular vesicles is complex, as their isolation and manipulation is still difficult to reproduce, which complicates the overview of their physiopathological effects. Nevertheless, new strategies have been developed to exploit the potential of extracellular vesicles and their cargo, both as biomarkers and as therapeutic tools to prevent the progression of fibrosis towards an irreversible event.

Extracellular vesicle-mediated cellular crosstalk in lung repair, remodelling and regeneration

The unperturbed lung is highly quiescent, with a remarkably low level of cell turnover. However, once damaged, the lung shows an extensive regenerative capacity, with resident progenitor cell populations re-entering the cell cycle and differentiating to promote repair. This quick and dramatic repair response requires interactions among more than 40 different cell lineages in the lung, and defects in any of these processes can lead to various lung pathologies. Understanding the mechanisms of interaction in lung injury, repair and regeneration thus has considerable practical and therapeutic implications. Moreover, therapeutic strategies for replacing lung progenitor cells and their progeny through cell therapy have gained increasing attention. In the last decade, extracellular vesicles (EVs), including exosomes, have been recognised as paracrine mediators through the transfer of biological cargo. Recent work has revealed that EVs are involved in lung homeostasis and diseases. In addition, EVs derived from specific cells or tissues have proven to be a promising cell-free modality for the treatment of lung diseases. This review highlights the EV-mediated cellular crosstalk that regulates lung homeostasis and discusses the potential of EV therapeutics for lung regenerative medicine.

Interstitial pneumonia and diffuse alveolar damage in domestic animals

Classification of pneumonia in animals has been controversial, and the most problematic pattern is interstitial pneumonia. This is true from the gross and histologic perspectives, and also from a mechanistic point of view. Multiple infectious and noninfectious diseases are associated with interstitial pneumonia, all of them converging in the release of inflammatory mediators that generate local damage and attract inflammatory cells that inevitably trigger a second wave of damage. Diffuse alveolar damage is one of the more frequently identified histologic types of interstitial pneumonia and involves injury to alveolar epithelial and/or endothelial cells, with 3 distinct stages. The first is the “exudative” stage, with alveolar edema and hyaline membranes. The second is the “proliferative” stage, with hyperplasia and reactive atypia of type II pneumocytes, infiltration of lymphocytes, plasma cells, and macrophages in the interstitium and early proliferation of fibroblasts. These stages are reversible and often nonfatal. If damage persists, there is a third “fibrosing” stage, characterized by fibrosis of the interstitium due to proliferation of fibroblasts/myofibroblasts, persistence of type II pneumocytes, segments of squamous metaplasia of alveolar epithelium, plus inflammation. Understanding the lesion patterns associated with interstitial pneumonias, their causes, and the underlying mechanisms aid in accurate diagnosis that involves an interdisciplinary collaborative approach involving pathologists, clinicians, and radiologists.

Growth Media Conditions Influence the Secretion Route and Release Levels of Engineered Extracellular Vesicles

Extracellular vesicles (EVs) are nanosized cell-derived vesicles produced by all cells, which provide a route of intercellular communication by transmitting biological cargo. While EVs offer promise as therapeutic agents, the molecular mechanisms of EV biogenesis are not yet fully elucidated, in part due to the concurrence of numerous interwoven pathways which give rise to heterogenous EV populations in vitro. The equilibrium between the EV-producing pathways is heavily influenced by factors in the extracellular environment, in such a way that can be taken advantage of to boost production of engineered EVs. In this study, a quantifiable EV-engineering approach is used to investigate how different cell media conditions alter EV production. The presence of serum, exogenous EVs, and other signaling factors in cell media alters EV production at the physical, molecular, and transcriptional levels. Further, it is demonstrated that the ceramide-dependent EV biogenesis route is the major pathway to production of engineered EVs during optimized EV-production. These findings suggest a novel understanding to the mechanisms underlying EV production in cell culture which can be applied to develop advanced EV production methods.

The Role of Extracellular Vesicles in Idiopathic Pulmonary Fibrosis Progression: An Approach on Their Therapeutics Potential

Idiopathic pulmonary fibrosis (IPF) is a fibrosing interstitial lung disease of unknown etiology. Different types of cells are involved in fibrogenesis, which is persistently physical and molecular stimulation, either directly or by interacting with bioactive molecules and extracellular vesicles (EVs). Current evidence suggests that EVs play an essential role in IPF development. EVs are released by a variety of cells, including fibroblasts, epithelial cells, and alveolar macrophages. In addition, EVs can transport bioactive molecules, such as lipids, proteins, and nucleic acids, which play a pivotal role in cellular communication. Several proposed mechanisms show that an acceptor cell can capture, absorb, or interact with EVs through direct fusion with the plasma membrane, ligand–receptor interaction, and endocytotic process, modifying the target cell. During fibrogenesis, the release of EVs is deregulated, increases the EVs amount, and the cargo content is modified. This alteration is closely associated with the maintenance of the fibrotic microenvironment. This review summarizes the current data on the participation of EVs secreted by the cells playing a critical role in IPF pathogenesis.

The Functional Role of Extracellular Matrix Proteins in Cancer

The extracellular matrix (ECM) is highly dynamic as it is constantly deposited, remodeled and degraded to maintain tissue homeostasis. ECM is a major structural component of the tumor microenvironment, and cancer development and progression require its extensive reorganization. Cancerized ECM is biochemically different in its composition and is stiffer compared to normal ECM. The abnormal ECM affects cancer progression by directly promoting cell proliferation, survival, migration and differentiation. The restructured extracellular matrix and its degradation fragments (matrikines) also modulate the signaling cascades mediated by the interaction with cell-surface receptors, deregulate the stromal cell behavior and lead to emergence of an oncogenic microenvironment. Here, we summarize the current state of understanding how the composition and structure of ECM changes during cancer progression. We also describe the functional role of key proteins, especially tenascin C and fibronectin, and signaling molecules involved in the formation of the tumor microenvironment, as well as the signaling pathways that they activate in cancer cells.

Extracellular Vesicles in Pulmonary Fibrosis Models and Biological Fluids of Interstitial Lung Disease Patients: A Scoping Review

INTRODUCTION

Interstitial lung diseases (ILDs) are a heterogeneous group of diffuse parenchymal lung disorders characterized by the pathogenetic involvement of interstitium. Therefore, an elucidation of the etiology and pathogenesis as well as the identification of diagnostic and prognostic biomarkers of such diseases is more compelling than ever. It is of note that there is increasing evidence of the involvement of extracellular vesicles (EVs) in the pathogenesis of lung diseases including lung cancer, chronic obstructive pulmonary disease and pulmonary fibrosis. It has been speculated that EVs play a pivotal role as mediators of intercellular communication, as well as the highlighting of the role of EVs as co-operators in the development of lung diseases such as IPF.

METHODS

The present study aimed to carry out a systematic exploratory search of the literature (through the scoping review approach) to identify and systematize the main results of the pathogenetic role of EVs in pulmonary fibrosis models and biological fluids from ILD patients, including plasma, bronchoalveolar lavage (BAL) and sputum.

CONCLUSION

Fibroblast-to-mesenchymal differentiation, collagen and extracellular matrix deposition are key mechanisms in the development and progression of IPF. EV-coupled miRNA are important modulators of biological processes in terms of intercellular communication as shown in pulmonary fibrosis models as well as biofluids. The helpfulness of EVs as diagnostic and theranostic markers is worth further investigation. The evolving potential of EVs to translate effective EV-based therapies into clinical practice is of growing interest, due to the urgent need for novel therapeutic strategies for IPF patients.

Extracellular Vesicles in Airway Homeostasis and Pathophysiology

The epithelial–mesenchymal trophic unit (EMTU) is a morphofunctional entity involved in the maintenance of the homeostasis of airways as well as in the pathogenesis of several diseases, including asthma and chronic obstructive pulmonary disease (COPD). The “muco-microbiotic layer” (MML) is the innermost layer of airways made by microbiota elements (bacteria, viruses, archaea and fungi) and the surrounding mucous matrix. The MML homeostasis is also crucial for maintaining the healthy status of organs and its alteration is at the basis of airway disorders. Nanovesicles produced by EMTU and MML elements are probably the most important tool of communication among the different cell types, including inflammatory ones. How nanovesicles produced by EMTU and MML may affect the airway integrity, leading to the onset of asthma and COPD, as well as their putative use in therapy will be discussed here.

Roles of extracellular vesicles in the aging microenvironment and age-related diseases

Cellular senescence is a persistently hypoproliferative state with diverse stressors in a specific aging microenvironment. Senescent cells have a double-edged sword effect: they can be physiologically beneficial for tissue repair, organ growth, and body homeostasis, and they can be pathologically harmful in age-related diseases. Among the hallmarks of senescence, the SASP, especially SASP-related extracellular vesicle (EV) signalling, plays the leading role in aging transmission via paracrine and endocrine mechanisms. EVs are successful in intercellular and interorgan communication in the aging microenvironment and age-related diseases. They have detrimental effects on downstream targets at the levels of immunity, inflammation, gene expression, and metabolism. Furthermore, EVs obtained from different donors are also promising materials and tools for antiaging treatments and are used for regeneration and rejuvenation in cell-free systems. Here, we describe the characteristics of cellular senescence and the aging microenvironment, concentrating on the production and function of EVs in age-related diseases, and provide new ideas for antiaging therapy with EVs.

Cellular Integrin α5β1 and Exosomal ADAM17 Mediate the Binding and Uptake of Exosomes Produced by Colorectal Carcinoma Cells

Approximately 25% of colorectal cancer (CRC) patients develop peritoneal metastasis, a condition associated with a bleak prognosis. The CRC peritoneal dissemination cascade involves the shedding of cancer cells from the primary tumor, their transport through the peritoneal cavity, their adhesion to the peritoneal mesothelial cells (PMCs) that line all peritoneal organs, and invasion of cancer cells through this mesothelial cell barrier and underlying stroma to establish new metastatic foci. Exosomes produced by cancer cells have been shown to influence many processes related to cancer progression and metastasis. In epithelial ovarian cancer these extracellular vesicles (EVs) have been shown to favor different steps of the peritoneal dissemination cascade by changing the functional phenotype of cancer cells and PMCs. Little is currently known, however, about the roles played by exosomes in the pathogenesis and peritoneal metastasis cascade of CRC and especially about the molecules that mediate their interaction and uptake by target PMCs and tumor cells. We isolated exosomes by size−exclusion chromatography from CRC cells and performed cell-adhesion assays to immobilized exosomes in the presence of blocking antibodies against surface proteins and measured the uptake of fluorescently-labelled exosomes. We report here that the interaction between integrin α5β1 on CRC cells (and PMCs) and its ligand ADAM17 on exosomes mediated the binding and uptake of CRC-derived exosomes. Furthermore, this process was negatively regulated by the expression of tetraspanin CD9 on exosomes.

Proteomic Analysis Reveals Key Proteins in Extracellular Vesicles Cargo Associated with Idiopathic Pulmonary Fibrosis In Vitro

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, irreversible, and highly fatal disease. It is characterized by the increased activation of both fibroblast and myofibroblast that results in excessive extracellular matrix (ECM) deposition. Extracellular vesicles (EVs) have been described as key mediators of intercellular communication in various pathologies. However, the role of EVs in the development of IPF remains poorly understood. This study aimed to characterize the differentially expressed proteins contained within EVs cargo derived from the fibroblast cell lines LL97A (IPF-1) and LL29 (IPF-2) isolated from lungs bearing IPF as compared to those derived from the fibroblast cell lines CCD8Lu (NL-1) and CCD19Lu (NL-2) isolated from healthy donors. Isolated EVs were subjected to label-free quantitative proteomic analysis by LC-MS/MS, and as a result, 331 proteins were identified. Differentially expressed proteins were obtained after the pairwise comparison, including all experimental groups. A total of 86 differentially expressed proteins were identified in either one or more comparison groups. Of note, proteins involved in fibrogenic processes, such as tenascin-c (TNC), insulin-like-growth-factor-binding protein 7 (IGFBP7), fibrillin-1 (FBN1), alpha-2 collagen chain (I) (COL1A2), alpha-1 collagen chain (I) (COL1A1), and lysyl oxidase homolog 1 (LOXL1), were identified in EVs cargo isolated from IPF cell lines. Additionally, KEGG pathway enrichment analysis revealed that differentially expressed proteins participate in focal adhesion, PI3K-Akt, and ECM–receptor interaction signaling pathways. In conclusion, our findings reveal that proteins contained within EVs cargo might play key roles during IPF pathogenesis.

Small extracellular vesicle-packaged TGFβ1 promotes the reprogramming of normal fibroblasts into cancer-associated fibroblasts by regulating fibronectin in head and neck squamous cell carcinoma

Tumor development and progression hinge upon ongoing coevolution and crosstalk with the tumor microenvironment. In particular, fibroblasts in the tumor stroma are coopted to support tumor growth and survival through interactions with tumor cells. Despite their significant importance, there is no consensus on the origin of cancer-associated fibroblasts (CAFs) in head and neck squamous cell carcinoma (HNSCC). In this study, we demonstrated that small extracellular vesicle (sEV)-packaged TGFβ1 can reprogram normal fibroblasts (NFs) into CAFs both in vitro and in vivo. Mechanistically, TGFβ1 in sEV activated NFs by regulating fibronectin, rather than modulating the canonical TGFβ-Smad signal pathway. Furthermore, TGFβ1 and fibronectin are related to HNSCC clinicopathologic features. Plasma sEV TGFβ1 may serve as a potential diagnostic biomarker for HNSCC. This hitherto unknown mechanism of reprogramming of NFs into CAFs by a unique pathway has major implications for underlying cancer-recruited stroma responses.

Exploring interactions between extracellular vesicles and cells for innovative drug delivery system design

Extracellular vesicles (EVs) are submicron cell-secreted structures containing proteins, nucleic acids and lipids. EVs can functionally transfer these cargoes from one cell to another to modulate physiological and pathological processes. Due to their presumed biocompatibility and capacity to circumvent canonical delivery barriers encountered by synthetic drug delivery systems, EVs have attracted considerable interest as drug delivery vehicles. However, it is unclear which mechanisms and molecules orchestrate EV-mediated cargo delivery to recipient cells. Here, we review how EV properties have been exploited to improve the efficacy of small molecule drugs. Furthermore, we explore which EV surface molecules could be directly or indirectly involved in EV-mediated cargo transfer to recipient cells and discuss the cellular reporter systems with which such transfer can be studied. Finally, we elaborate on currently identified cellular processes involved in EV cargo delivery. Through these topics, we provide insights in critical effectors in the EV-cell interface which may be exploited in nature-inspired drug delivery strategies.

Changes in the proteome of extracellular vesicles shed by rat liver after subtoxic exposure to acetaminophen

To identify changes in extracellular vesicles (EVs) secreted by the liver following drug-induced liver injury (DILI), rats were treated with a subtoxic dose (500 mg/kg) of the analgesic drug, acetaminophen (APAP). EVs were collected by liver perfusion of sham and APAP-treated rats. Changes in EVs morphology were examined by transmission electron microscopic analysis of negatively stained vesicles. Results from morphometric analysis of EVs revealed striking differences in their size and distribution. Proteome composition of EVs collected by liver perfusion was determined by mass spectrometry using methods of sample preparation that enabled better detection of both highly hydrophobic proteins and proteins with complex post-translational modifications. The collection of EVs after liver perfusion is an approach that enables the isolation of EVs shed not only by isolated hepatocytes, but also by the entire complement of hepatic cells. EVs derived after DILI had a lower content of alpha-1-macroglobulin, ferritin, and members of cytochrome 450 family. Fibronectin, aminopeptidase N, metalloreductase STEAP4, integrin beta, and members of the annexin family were detected only in APAP-treated samples of EVs. These results show that the present approach can provide valuable insights into the response of the liver following drug-induced liver injury.

Extracellular Vesicles: An Emerging Mechanism Governing the Secretion and Biological Roles of Tenascin-C

ECM composition and architecture are tightly regulated for tissue homeostasis. Different disorders have been associated to alterations in the levels of proteins such as collagens, fibronectin (FN) or tenascin-C (TnC). TnC emerges as a key regulator of multiple inflammatory processes, both during physiological tissue repair as well as pathological conditions ranging from tumor progression to cardiovascular disease. Importantly, our current understanding as to how TnC and other non-collagen ECM components are secreted has remained elusive. Extracellular vesicles (EVs) are small membrane-bound particles released to the extracellular space by most cell types, playing a key role in cell-cell communication. A broad range of cellular components can be transported by EVs (e.g. nucleic acids, lipids, signalling molecules and proteins). These cargoes can be transferred to target cells, potentially modulating their function. Recently, several extracellular matrix (ECM) proteins have been characterized as bona fide EV cargoes, exosomal secretion being particularly critical for TnC. EV-dependent ECM secretion might underpin diseases where ECM integrity is altered, establishing novel concepts in the field such as ECM nucleation over long distances, and highlighting novel opportunities for diagnostics and therapeutic intervention. Here, we review recent findings and standing questions on the molecular mechanisms governing EV–dependent ECM secretion and its potential relevance for disease, with a focus on TnC.

Structural and mechanical characteristics of exosomes from osteosarcoma cells explored by 3D-atomic force microscopy

Exosomes have recently gained interest as mediators of cell-to-cell communication and as potential biomarkers for cancer and other diseases. They also have potential as nanocarriers for drug delivery systems. Therefore, detailed structural, molecular, and biomechanical characterization of exosomes is of great importance for developing methods to detect and identify the changes associated with the presence of cancer and other diseases. Here, we employed three-dimensional atomic force microscopy (3D-AFM) to reveal the structural and nanomechanical properties of exosomes at high spatial resolution in physiologically relevant conditions. The substructural details of exosomes released from three different cell types were determined based on 3D-AFM force mapping. The resulting analysis revealed the presence of distinct local domains bulging out from the exosome surfaces, which were associated with the exosomal membrane proteins present on the outer surface. The nanomechanical properties of individual exosomes were determined from the 3D-force maps. We found a considerably high elastic modulus, ranging from 50 to 350 MPa, as compared to that obtained for synthetic liposomes. Moreover, malignancy-dependent changes in the exosome mechanical properties were revealed by comparing metastatic and nonmetastatic tumor cell-derived exosomes. We found a clear difference in their Young's modulus values, suggesting differences in their protein profiles and other exosomal contents. Exosomes derived from a highly aggressive and metastatic k-ras-activated human osteosarcoma (OS) cell line (143B) showed a higher Young's modulus than that derived from a nonaggressive and nonmetastatic k-ras-wildtype human OS cell line (HOS). The increased elastic modulus of the 143B cell-derived exosomes was ascribed to the presence of abundant specific proteins responsible for elastic fiber formation as determined by mass spectroscopy and confirmed by western blotting and ELISA. Therefore, we conclude that exosomes derived from metastatic tumor cells carry an exclusive protein content that differs from their nonmetastatic counterparts, and thus they exhibit different mechanical characteristics. Discrimination between metastatic and nonmetastatic malignant cell-derived exosomes would be of great importance for studying exosome biological functions and using them as diagnostic biomarkers for various tumor types. Our findings further suggest that metastatic tumor cells release exosomes that express increased levels of elastic fiber-associated proteins to preserve their softness.

J or H mtDNA haplogroups in retinal pigment epithelial cells: Effects on cell physiology, cargo in extracellular vesicles, and differential uptake of such vesicles by naïve recipient cells

PURPOSE

Extracellular vesicles (EVs) are predicted to represent the internal state of cells. In polarized RPE monolayers, EVs can mediate long-distance communication, requiring endocytosis via protein-protein interactions. EV uptake from oxidatively stressed donor cells triggers loss in transepithelial resistance (TER) in recipient monolayers mediated by HDAC6. Here, we examine EVs released from RPE cells with identical nuclear genes but different mitochondrial (mt)DNA haplogroups (H, J). J-cybrids produce less ATP, and the J-haplogroup is associated with a higher risk for age-related macular degeneration.

METHODS

Cells were grown as mature monolayers to either collect EVs from apical surfaces or to serve as naïve recipient cells. Transfer assays, transferring EVs to a recipient monolayer were performed, monitoring TER and EV-uptake. The presence of known EV surface proteins was quantified by protein chemistry.

RESULTS

H- and J-cybrids were confirmed to exhibit different levels of TER and energy metabolism. EVs from J-cybrids reduced TER in recipient ARPE-19 cells, whereas EVs from H-cybrids were ineffective. TER reduction was mediated by HDAC6 activity, and EV uptake required interaction between integrin and its ligands and surface proteoglycans. Protein quantifications confirmed elevated levels of fibronectin and annexin A2 on J-cybrid EVs.

CONCLUSIONS

We speculate that RPE EVs have a finite set of ligands (membrane proteoglycans and integrins and/or annexin A2) that are elevated in EVs from stressed cells; and that if EVs released by the RPE could be captured from serum, that they might provide a disease biomarker of RPE-dependent diseases.

Hermansky-Pudlak Syndrome and Lung Disease: Pathogenesis and Therapeutics

Hermansky-Pudlak Syndrome (HPS) is a rare, genetic, multisystem disorder characterized by oculocutaneous albinism (OCA), bleeding diathesis, immunodeficiency, granulomatous colitis, and pulmonary fibrosis. HPS pulmonary fibrosis (HPS-PF) occurs in 100% of patients with subtype HPS-1 and has a similar presentation to idiopathic pulmonary fibrosis. Upon onset, individuals with HPS-PF have approximately 3 years before experiencing signs of respiratory failure and eventual death. This review aims to summarize current research on HPS along with its associated pulmonary fibrosis and its implications for the development of novel treatments. We will discuss the genetic basis of the disease, its epidemiology, and current therapeutic and clinical management strategies. We continue to review the cellular processes leading to the development of HPS-PF in alveolar epithelial cells, lymphocytes, mast cells, and fibrocytes, along with the molecular mechanisms that contribute to its pathogenesis and may be targeted in the treatment of HPS-PF. Finally, we will discuss emerging new cellular and molecular approaches for studying HPS, including lentiviral-mediated gene transfer, induced pluripotent stem cells (iPSCs), organoid and 3D-modelling, and CRISPR/Cas9-based gene editing approaches.

Fibronectin as a multiregulatory molecule crucial in tumor matrisome: from structural and functional features to clinical practice in oncology

Deciphering extracellular matrix (ECM) composition and architecture may represent a novel approach to identify diagnostic and therapeutic targets in cancer. Among the ECM components, fibronectin and its fibrillary assembly represent the scaffold to build up the entire ECM structure, deeply affecting its features. Herein we focus on this extraordinary protein starting from its complex structure and defining its role in cancer as prognostic and theranostic marker.

Role of extracellular vesicles in chronic lung disease

To explore the role of extracellular vesicles (EVs) in chronic lung diseases.

EVs are emerging as mediators of intercellular communication and possible diagnostic markers of disease. EVs harbour cargo molecules including RNA, lipids and proteins that they transfer to recipient cells. EVs are intercellular communicators within the lung microenvironment. Due to their disease-specific cargoes, EVs have the promise to be all-in-one complex multimodal biomarkers. EVs also have potential as drug carriers in chronic lung disease.

Descriptive discussion of key studies of EVs as contributors to disease pathology, as biomarkers and as potential therapies with a focus on chronic obstructive pulmonary disorder (COPD), cystic fibrosis (CF), asthma, idiopathic pulmonary fibrosis and lung cancer.

We provide a broad overview of the roles of EV in chronic respiratory disease. Recent advances in profiling EVs have shown their potential as biomarker candidates. Further studies have provided insight into their disease pathology, particularly in inflammatory processes across a spectrum of lung diseases. EVs are on the horizon as new modes of drug delivery and as therapies themselves in cell-based therapeutics.

EVs are relatively untapped sources of information in the clinic that can help further detail the full translational nature of chronic lung disorders.

Landscape of extracellular vesicles in the tumour microenvironment: Interactions with stromal cells and with non-cell components, and impacts on metabolic reprogramming, horizontal transfer of neoplastic traits, and the emergence of therapeutic resistance

Extracellular vesicles (EVs) are increasingly recognised as a pivotal player in cell-cell communication, an attribute of EVs that derives from their ability to transport bioactive cargoes between cells, resulting in complex intercellular signalling mediated by EVs, which occurs under both physiological and pathological conditions. In the context of cancer, recent studies have demonstrated the versatile and crucial roles of EVs in the tumour microenvironment (TME). Here, we revisit EV biology, and focus on EV-mediated interactions between cancer cells and stromal cells, including fibroblasts, immune cells, endothelial cells and neurons. In addition, we focus on recent reports indicating interactions between EVs and non-cell constituents within the TME, including the extracellular matrix. We also review and summarise the intricate cancer-associated network modulated by EVs, which promotes metabolic reprogramming, horizontal transfer of neoplastic traits, and therapeutic resistance in the TME. We aim to provide a comprehensive and updated landscape of EVs in the TME, focusing on oncogenesis, cancer progression and therapeutic resistance, together with our future perspectives on the field.