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Review

Diagnostic and Therapeutic Applications of Extracellular Vesicles in Interstitial Lung Diseases

by
Abdulrahman Ibrahim
1,
Ahmed Ibrahim
2 and
Tanyalak Parimon
3,*
1
Faculty of Medicine, University of Queensland/Ochsner Clinical School, New Orleans, LA 70121, USA
2
Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
3
Pulmonary and Critical Care Division, Women’s Guild Lung Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
*
Author to whom correspondence should be addressed.
Diagnostics 2021, 11(1), 87; https://doi.org/10.3390/diagnostics11010087
Submission received: 2 December 2020 / Revised: 1 January 2021 / Accepted: 1 January 2021 / Published: 7 January 2021
(This article belongs to the Special Issue Diagnostic Potential of Extracellular Vesicles (EVs) in Chronic Diseases)
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Abstract

:
Interstitial lung diseases (ILDs) are chronic irreversible pulmonary conditions with significant morbidity and mortality. Diagnostic approaches to ILDs are complex and multifactorial. Effective therapeutic interventions are continuously investigated and explored with substantial progress, thanks to advances in basic understanding and translational efforts. Extracellular vesicles (EVs) offer a new paradigm in diagnosis and treatment. This leads to two significant implications: new disease biomarker discovery that enables reliable diagnosis and disease assessment and the development of regenerative medicine therapeutics that target fibroproliferative processes in diseased lung tissue. In this review, we discuss the current understanding of the role of diseased tissue-derived EVs in the development of interstitial lung diseases, the utility of these EVs as diagnostic and prognostic tools, and the existing therapeutic utility of EVs. Furthermore, we review the potential therapeutic application of EVs derived from various cellular sources.

1. Introduction

Interstitial lung diseases (ILDs) are a wide spectrum of diffuse parenchymal pulmonary conditions indicated by inflammatory changes in the alveoli. ILDs may present either idiopathically or by a sequela to preexisting comorbidities such as connective tissue, autoimmune diseases, or secondary to biological, chemical, or fine particle exposure [1,2]. The American Thoracic Society (ATS) and European Respiratory Society (ERS) designated the term idiopathic interstitial pneumonia (IIP) for ILDs of unknown etiologies [3]. IIPs are further subdivided as major, rare, and unclassified IIP [4,5,6]. The natural course of ILDs is characterized by chronic, progressive, and irreversible fibrosis with significant morbidity and mortality [6,7,8,9]. While the management of non-idiopathic ILDs relies on addressing the underlying cause of disease, the standard treatment approaches for IIP include antifibrotic therapy or lung transplantation [10,11,12,13,14]. Although current treatments provide significant morbidity and mortality benefits [15], they are not curative. Extensive research in the pathogenesis of lung fibroproliferation has opened new avenues of therapeutic intervention. ILDs continue to levy significant burdens on morbidity, mortality, and healthcare expenditure worldwide [16,17,18,19]. Further understanding of the underlying pathogenic mechanisms is essential for more effective antifibrotic treatment approaches. A new and promising avenue of investigation relates to the role of extracellular vesicles (EVs) in parenchymal lung injury and interstitial fibrosis. The role of EVs in the pathogenesis of nonmalignant chronic respiratory conditions has been extensively described in ILDs [20,21,22], asthma [23,24], chronic obstructive pulmonary diseases (COPD) [23,25,26,27], and pulmonary hypertension [28,29]. These studies provide an evidence base for the clinical translation of EVs in ILD diagnosis and the utilization of therapeutic EVs for treatment.
EVs are easily quantifiable and have features amenable to direct (i.e., as treatments) and indirect (i.e., as diagnostic tools) therapeutic applications. These include stability, cargo transfer, and direct regulation of disease pathogenesis. The current gold standard of ILDs diagnosis is invasive procedures such as transbronchial cryobiopsy through bronchoscopy or surgical lung biopsy [30]. These approaches are associated with an increased risk of procedural complications and clinical intolerability, particularly in patients with respiratory insufficiency [30,31,32]. As a result, noninvasive and reliable biomarkers for ILDs are needed for more effective clinical management and care. Additionally, EVs can also be used to monitor disease progression and response to treatment. The physiologic and pathogenic roles of EVs suggests their utility as a therapeutic platform in the restoration of organ homeostasis and reversal of tissue damage. Indeed, the steady migration of cells to EV therapy in regenerative medicine is primarily due to the versatility of these particles over traditional cell transplantation therapy [22,33,34,35]. The advancement of EV cargo content engineering renders EVs more versatile and customizable to several disease types [36]. Despite significant progress, some limitations have limited the transition of EVs to clinical studies [37]. Therefore, this review focuses on the current understanding of the molecular pathways that drive ILDs and the role of EVs in disease progression. We further discuss the applicability of EV translation in the context of biomarker development and EV therapy.

2. Extracellular Vesicles

Extracellular vesicles are lipid bilayer nanoparticles secreted by nearly all cell types and comprise several classes of particles delineated by size and pathway of biogenesis. For instance, exosomes are smaller (30–150 nm) particles produced through the late endosome with selective packaging of cargo. Ectosomes (e.g., microvesicles, apoptosomes, etc.) (100 nm–1 µm) are passively shed from the plasma membrane. However, evidence from the cancer biology and hypersensitivity models demonstrates that ectosome content will change based on different cell stimuli (i.e., stress, antigen exposure, etc.) [38]. Whether this is a reflection of the internal contents of the cell (in response to stimuli) or evidence of bona fide cargo-sorting remains to be verified. However, a recent report indicated that pyruvate kinase M2 (PKM2) can be sorted into hepatocellular carcinoma ectosomes through the sumoylation process [39]. EVs also carry a plethora of signaling mediators including several classes of non-coding RNAs (micro-RNAs, long noncoding RNAs, Piwi RNAs, etc.), proteins (growth factors, transcription factors, etc.), and lipids [40,41]. The discovery of extracellular vesicles [42,43] and their biological roles appears to be significant in a variety of human diseases, namely in chronic conditions such as pulmonary disease, cancer, diabetes, heart diseases, Alzheimer’s disease, kidney failure, liver cirrhosis, etc. [44,45,46,47,48,49]. Primarily, the demonstration of EVs facilitating intercellular communication has created a paradigm shift in our understanding of disease pathogenesis [50]. It offers novel tools that aid in the fundamental understanding of basic disease pathogenesis and the development of novel diagnostic and therapeutic platforms [51]. EVs play essential functional roles in maintaining tissue/organ homeostasis during normal development [52,53] and also in disease progression including tissue damage, fibrosis, and metastasis [54,55,56]. The biological functions of EVs rely on signal transduction of EV-associated cargo molecules which alter the transcriptome and epigenome of recipient cells. These EVs mediate communication and phenotypic change within and between tissues [45,46,47,48].

3. EVs in Ild Pathogenesis

The key cellular players in ILD pathogenesis include alveolar epithelial cells, lung fibroblasts, leukocytes, and endothelial cells [57]. Crosstalk between these cell types in the context of the injured lung microenvironment is mediated, at least in part, by EVs [58]. For instance, alveolar macrophage-, neutrophil-, and epithelial cell-derived EVs sampled from bronchoalveolar lavage fluid (BALF) mediate the acute and resolution phases of acute lung injury through the transfer of proinflammatory cytokines including TNF-α, IL-6, and IL1-β [59,60,61]. Indeed, in EVs isolated from human healthy volunteers, BALF carries MHC I and II, CD54, CD63, and the co-stimulatory molecule CD86, implicating their potential roles in immune regulation [62]. Similar studies in other chronic respiratory conditions (e.g., asthma, COPD, and lung cancer) confirm the disease-propagating role of EVs [63,64]. These findings highlight the importance of EVs in lung microenvironment signaling. Furthermore, through universal inflammatory and fibrotic processes, EVs are likely to play similarly critical roles in ILDs.

3.1. EVs in Nonidiopathic Interstitial Lung Diseases

Nonidiopathic ILDs are defined as ILDs with known causes, such as connective tissue disorders, toxic environmental exposures, or chronic inflammatory lung diseases such as sarcoidosis [65]. The implication of EVs in non idiopathic ILDS is gaining increasing interest. A higher quantity of EV-associated proteins, called tissue factor (TF), were found in microvesicles (MVs, size ranged 0.05–1 μm) in the BALF of pulmonary fibrosis cases (4 known cause ILDs and 15 IIP patients). EV-bound tissue factor (TF) activity was associated with disease severity, highlighting the possible causal relationship between pathogenic MVs and lung damage [66]. TF-bearing MVs stimulated reactive oxygen species (ROS) production in human lung epithelial cell lines (A549 and NHBEC), suggesting that these MVs propagate injury (and fibrosis development) across the pulmonary epithelium.
A few studies of pulmonary sarcoidosis, a chronic inflammatory ILD, showed that sarcoidosis patients had a higher EV-burden in their BALF [67,68,69]. These EVs retained proinflammatory properties as demonstrated by their capacity to induce interferon-γ (IFNγ) and interleukin IL-13 production in peripheral blood mononuclear cells (PBMCs) and IL-8 from epithelial cells [67]. Others also reported that BALF-derived EVs from sarcoidosis patients stimulated monocytes to release IL-1β, IL-6, CCL2, and Tumor Necrosis Factor (TNF) [69]. These proinflammatory mediators promote lung inflammation that leads to fibrosis progression in patients with sarcoidosis. Therefore, EVs carry specific cargoes that can induce inflammatory responses in both immune and lung epithelial cells. Further characterization of these cargoes and their involvement in lung fibroproliferation is needed to understand the contribution of EVs to ILD pathogenesis and prognosis.

3.2. EVs in Idiopathic Interstitial Lung Diseases

The most common interstitial lung disease in this category is idiopathic pulmonary fibrosis (IPF). Single-cell RNA-sequencing of human and mouse lungs indicated that many cell types in the lungs are involved in IPF pathogenesis [70,71]. Most of those cells secrete EVs that drive lung fibroproliferative processes through activation of profibrotic signaling pathways such as transforming growth factor β (TGFβ) signaling, wingless N-type (Wnt)/β-catenin signaling, and cellular senescence.
EVs mediate lung fibroproliferation through the activation of TGFβ signaling, a well-established profibrotic pathway. It has been shown that TGFβ stimulates human and mouse fibroblasts to secrete EVs enriched in Program Death Ligand-1 (PD-L1) protein [72]. EV-associated PD-L1 further promotes lung fibroblast activation, proliferation, and paracrine-mediated suppression of T cell proliferation [72]. We and others have shown that EV-associated miRNAs from injured tissue have lower levels of antifibrotic TGFβ -regulating miRs [21]. In particular, miR-144-3p, miR-142-3p miR-34-b, and miR-503-5p are depleted in injured lung epithelial cell-derived EVs. MiR-144-3p and miR-142-3p also inhibit phosphorylation of the SMAD2 protein in a mouse bleomycin-induced lung injury model [21]. Moreover, macrophage-derived EVs downregulate the expression of TGFβ receptor 1 (TGFβ-R1) and profibrotic genes in lung epithelial cells and lung fibroblasts through miR-142-3p [73]. Others showed that IL-1β activation on lung fibroblasts stimulated EV-associated prostaglandin E2 (PGE2) production. PGE2 in the EVs can downregulate TGFβ signaling on lung fibroblasts through autocrine and paracrine effects [74]. In summary, EVs carry proteins and microRNAs that modulate TGFβ signaling, a major pathway of lung fibroproliferation.
Another major profibrotic pathway modulated by EVs is the Wnt signaling pathway. Lung-derived EVs following bleomycin injury are enriched in WNT5A, a noncanonical Wnt ligand [75]. Exposing healthy lung fibroblasts to WNT5A triggered fibroblast activation and proliferation, leading to collagen production [75]. Similarly, exposing lung fibroblasts to TGFβ also induced WNT5A and promoted fibroblast activation and fibrotic expansion. Another study showed that EVs derived from lung fibroblasts of IPF patients were enriched in fibronectin (FN), a protein that accumulates in lung fibrotic tissue and increases [20] fibroblast invasiveness and lung fibro proliferation through focal adhesion kinase (FAK) and Src family kinases activation [20]. Others have demonstrated that Wnt activation further induces FN expression [76].
Another principal driving pathway in lung fibrosis is cellular senescence [77,78]. The involvement of EVs in other chronic lung diseases such as COPD and lung cancer through cellular senescence was reviewed previously [79]. In ILD, one study showed that IPF fibroblast EV-associated miR-23b-3p and miR-494-3p induced human bronchial epithelial cells= senescence by suppressing SIRT3 expression, mitochondrial damage in epithelial cells, and senescence [80]. We have shown that EVs from human IPF lungs and bleomycin-injured mouse lungs had lower levels of antifibrotic miRNAs such as miR-144-3p, miR-142-3p, miR-34-b, and miR-503-5p that regulate cellular senescence, suggesting that EVs from diseased states are prosenescent and profibrotic [21].
In summary, EVs play a significant role in ILD progression and, in the diseased state, drive lung fibroproliferative processes by activating pathogenic pathways in healthy tissue (Figure 1). This suggests that EVs from patient samples can serve as diagnostic tools and that diseased tissue may be responsive to EV therapy. The former supports the role of EVs as biomarkers, and the latter supports their application in therapy [21,74].

4. Extracellular Vesicles as Biomarkers

While the roles of EVs as a diagnostic tool are rapidly developing for malignant neoplastic diseases such as lung cancer, this application remains in its early stages regarding ILD. The contributing factors include insufficient characterization of EV cargoes in patient samples [81,82] and the low efficiency of obtaining EVs from clinical specimens for an accurate diagnosis. However, in recent years, the tremendous progression of diagnostic EVs in cancer has helped facilitate the utilization of EVs as biomarkers for ILDs. Efforts to support the future translation of EV as biomarkers are focused on the development of more practical yet efficient methods of EV isolation from clinical specimens [83].
miRNAs are widely studied cargo in EVs and have long been implicated in ILD pathogenesis. Differential expression of circulating miRNAs during different stages of IPF progression suggests that these extracellular miRNAs may be used as biomarkers for diagnosis and staging [84]. We postulate that differential expression of these miRNAs may also be found in circulating EVs. One study demonstrated an increase of profibrotic miRNAs (miR-7 and miR-125) and decreased antifibrotic miRNA (miR-141) in serum-derived EVs from IPF patients, suggesting that serum EV-associated miRNAs play a significant role in pathogenesis [85]. In the preclinical model, circulating EV-miR-21-5p was first found in mice with bleomycin-lung injuries. This model was further validated in the human serum of IPF patients [86]. More importantly, serum EV-levels of miR-21-5p were correlated with increasing mortality risk at 30 months, supporting its role as a biological marker for disease severity. Recently, others demonstrated an upregulation of miR-21 in the serum-derived EVs of premature infants with chronic lung disease (CLD) indicating that miR-21 can be used as a predictive biomarker for CLD in this population [87]. Noncirculating EV-associated miRNAs are also evaluated; for example, one report showed that IPF patients displayed distinct miRNA profiles in sputum EVs compared to healthy controls, suggesting that these miRNAs may be profibrotic [88]. Further identification of miRNAs demonstrated that certain miRNAs (miR-142-3p, miR-33a-5p, and Let-7d-5p) were correlated with disease severity. Although the development and internal validation cohort in this study were small, it provides a foundation for future work in a larger cohort. The second study evaluating lung fibroblast-derived EVs revealed similar findings; IPF lung fibroblast-derived EVs were enriched in miR-23b-3p and miR-494-3p, which correlated with disease severity [80]. Together, microRNA-associated EVs derived from sputum, BALF, and circulation can potentially be used as diagnostic and prognostic markers for ILD.
EV protein cargo has also gained interest as a biomarker recently. Proteomic analysis of EVs from BALF of 15 pulmonary sarcoidosis patients demonstrated increased levels of pro-inflammatory proteins such as cell-cell glycoproteins, LPS-binding proteins, vitamin D binding proteins (VDBP), and complement activating proteins [68]. VDBP level was further validated in a different cohort of BALF- and serum-derived EVs of sarcoidosis patients, reinforcing the utility of EV protein biomarkers in patients with pulmonary sarcoidosis. In addition to EV-associated cargos, the role of cell-specific EVs was reported among ILD patients, whereby circulating endothelial cell-derived EVs were significantly elevated as quantitated by flow cytometry [89].
In conclusion, despite the need for further investigation findings from sputum-, BALF-, and serum-derived EVs represent promising points of ILD diagnostic development.

5. Therapeutic Roles of Extracellular Vesicles

EVs represent more versatile and scalable therapeutics than cell therapy as they are a noncell based therapeutic approach, and these include recapitulating the full therapeutic effect of the parent cells themselves, which are nonliving and unchanging entities, and are less immunogenic [36,37,83]. The reparative, antifibrotic, and immunomodulatory properties of EVs represent critical points of mechanistic interventions in ILD treatment [22]. At the current stage, therapeutic EVs studies are in the preclinical phase and many challenges remain to be investigated before EVs can be transitioned into clinical studies [33,37]. Nonetheless, results from preclinical studies, are encouraging and indicate promising therapeutic options (Table 1).
Many therapeutic cell-derived EV candidates with antifibrotic properties exist for ILDs, including mesenchymal stem cells (MSC), cardiosphere-derived cells, and healthy lung tissue [98]. The most common source of MSCs is bone marrow. Recent work demonstrated that bone marrow-MSC-derived EVs suppress fibroblast proliferation and lung fibrosis by downregulating Frizzled Class Receptor 6 (FZD6) expression in fibroblasts through miR-29b-3p both in vitro and in vivo [90]. Others also showed that MSC-EVs-miR-214-3p may alleviate radiation-induced lung injury and lung fibrosis in mice by downregulating ataxia telangiectasia mutated (ATM) kinase through suppression of ATM/P53/P21 signaling and thereby inhibiting the senescence in endothelial cells [91]. It has also been shown that human bone-MSC EVs can prevent and revert bleomycin-induced lung fibrosis [92] as demonstrated by the administration of these EVs at or after bleomycin injury. The protective effects of these EVs were more pronounced than their reversal of existing fibrosis. The EVs were also shown to modulate local macrophage- and monocyte-proinflammatory activation, though the specific mechanism remains to be described. EVs derived from MSC and lung spheroid cells (LSCs) also demonstrated therapeutic efficacy in bleomycin- and silica-induced lung fibrosis [93]. Using transcriptomic and proteomic analysis of EV cargo, it was postulated that miR-10a, miR-99, and let-7 along with MMP2 and TIMPs were mediating these beneficial effects. This study was among the first to administer EV therapy through inhalational administration and demonstrate antifibrotic activity.
Adipose mesenchymal stem cells (ADSCs) are another source of EVs that have been shown to significantly reduce primary lung injury and pulmonary fibrosis in rat lungs exposed to fine particulate matter less than 2.5 µm (PM2.5), demonstrating that pulmonary fibrosis is mitigated in part by let-7d-5p targeting TGFβ-R1 [94]. Specifically, the intratracheal administration of rat ADSC-EVs 1 h after PM2.5 exposure can suppress TGFβ-RI on alveolar type II cells that in turn prevents downstream events of the TGFβ signaling pathway.
Cardiosphere-derived cells (CDCs) are a population of cardiac-derived stromal cells with demonstrated disease-modifying activity in cardiac and skeletal muscle indications [95]. The mechanisms of action of CDC therapy include immunomodulation, antifibrosis, and tissue repair [95]. CDCs function primarily through the secretion of EVs which, on their own, recapitulate the full therapeutic effect of the parent cells [99]. Recent studies have identified CDC–EV cargo that mediates their immunomodulatory and antifibrotic effects. For instance, CDC–EVs contain keystone immunoregulatory miRs, including miR-146a and miR-181b, which attenuate innate immune inflammation through the suppression of the NFκB pathway and classical macrophage polarization, respectively [99]. MiR-146a also targets the TGFβ pathway through the suppression of Smad4. Furthermore, they contain other noncoding RNA species, including YRNA, which attenuate inflammation through the activation of IL10 secretion. Also, CDC–EVs are enriched in miR-24, which suppresses TGFβ signaling through the targeting of Furin [100]. Given what is already known about CDC–EV cargo and the pathways these signals affect in recipient cells, CDC–EVs represent promising therapeutics for ILDs.
Other cellular sources of therapeutic EVs are obtained directly from well-differentiated cells, including lung epithelial cells, lung fibroblasts, and immune cells. Our group has shown that lung-derived epithelial cell EVs, collected from syndecan-1 deficient mice, alleviated bleomycin-induced lung fibrosis by the activity of miRNA-associated EVs such as miR-142-3p, miR-144-3p, miR-34b, and miR-503-5p by targeting various profibrotic pathways [21]. Others have demonstrated that human amnion epithelial cell-derived EVs modulate bleomycin-induced lung remodeling and revert lung fibrosis by reducing lung epithelial cell damage and subepithelial myofibroblast accumulation [101]. EV-mediated lung repair was found to be superior to pirfenidone (a current antifibrotic agent for IPF) and its effects were enhanced by serelaxin, suggesting that these EVs may be deployed as adjunctive therapy. Additionally, human amnion epithelial cell-derived EVs exert their antifibrotic and regenerative effects in bleomycin lung injuries in both young and aged mice [96]. These effects are presumed to be associated with miRNAs and proteins targeting profibrotic signaling pathways.
A few cell lines have also been considered as sources of therapeutic EVs. For example, the neutrophil cell line (HL-60) secretes EVs containing miR-1343 that can be taken up by alveolar epithelial cells and lung fibroblasts, further inhibiting TGFβ, a major profibrotic regulatory signaling pathway modulator [97]. Macrophages are another source of EVs that contain miR-142-3p, which inhibits a profibrotic activation in epithelial cells and lung fibroblasts by downregulating TGFβRI [73]. The EVs from IL-1β activated human lung fibroblasts contained PGE2 that inhibited myofibroblast differentiation and collagen production, implicating their antifibrotic properties for in vivo testing [74].
Currently, there are nearly 600 clinical trials (registered, ongoing, and completed) worldwide using EVs in diagnostic and therapeutic capacities. Of these only 32 are related to lung disease. More than 60% of these studies focused on pulmonary malignancies, 20% focused on severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) or COVID-19 infection, and the remainder was distributed among COPD, sarcoidosis, cystic fibrosis, and liver transplantation (www.clinicaltrials.gov with search terms “extracellular vesicles, microvesicles, exosomes”). Despite the sizable increase of clinical trials over the years, challenges with therapeutic translation of EVs remain. As with all other therapeutics, the primary challenge is effective delivery. Despite many features of EVs that make them an attractive therapeutic platform, they have little to no specific tissue tropism, as most biodistribution studies of systemically infused EVs demonstrate [102,103]. Secondly, owing to their diminutive size, retaining them at a certain site or target tissue is challenging as they are easily flushed by circulation. Therefore, for indications that require the direct application of EVs to localized areas (e.g., ischemic injury), patches of various hydrogels have been developed as scaffolds to provide consistent retention and release [104,105]. More specific EV delivery-enhancement efforts have focused on altering the EV surface for improved tissue retention, including the use of chemically-embedded targeting antibodies or homing peptides [106]. Furthermore, for EVs to be a viable therapy, a steady source of producer cells is needed. Current strategies are built around a single use paradigm for producer cells. For primary cell-derived EVs (currently the majority of therapeutic EVs), scale-up becomes prohibitive and would otherwise require a steady and ample source. One answer to this challenge has been the immortalization of producer cells as a steady source of therapeutic EVs [107]. More recently, we and others have developed immortalization strategies guided by the mechanistic understanding of the pathways that contribute to producer cell (and EV) potency [108,109]. Other strategies aimed at altering the EV surface include the stable introduction of a transgene expressing a chimeric protein comprising the intracellular domain of a conserved EV-surface receptor such as CD63 [110] or Lamp2b [111], which is fused to the extracellular portion of a protein of interest.
Furthermore, as the investigation of EV cargo advances into the identification of defined factors, new platforms, and strategies for enhancing EV bioactivity and improving therapeutic potency continue to be developed. Indeed, many reports of therapeutic EVs have identified therapeutically relevant cargo that triggers tissue healing and repair through attenuation of inflammation and fibrosis, promotion of tissue protection, repair, and angiogenesis [34,112]. Many of these defined factors include miRNAs, other small RNAs, and proteins [95,102]. For instance, some strategies exploit the ubiquitination pathway by tagging proteins of interest with various versions of a “ubiquitination” signal, which prompts efficient binding and EV loading by the trafficking protein Ndfip1 [111]. Another strategy for protein loading into EVs involves fusing the protein of interest with the trafficking domain of Nef1, an HIV lipid raft trafficking protein with the ability to sort proteins into vesicles [113]. For small RNAs, more straightforward methods that do not involve the engineering of the producer cell are the prevalent approach. These include the common nucleic acid and small molecule drug loading methods including EV electroporation, cationic lipid-mediated transfection of EVs or producer cells, EV sonication, and temperature–shock transfection, among others [114,115]. Recent findings, however, have elucidated the mechanisms by which miRs are preferentially sorted into EVs, including the identification of 3′ EV-localization sequences (GGAG/UGCA and AGG/UAG) that were recognized for sorting into EVs by heterogeneous ribonuclear proteins [116]. Therefore, an emerging strategy is the stable transfection of a miR of interest incorporating this trimer sequencing to increase packaging in the EV payload (Figure 2).
In summary, EVs show significant promise as a noncell regenerative medicine treatment [117]. Though challenges remain, the constant progress in mechanistic understanding, the identification of defined factors, and the development of genetic and material engineering are moving EVs towards clinical viability [37,118].

6. Conclusions

EVs have revolutionized our approach and understanding of ILD pathogenesis and can potentially be used as biomarkers and therapeutics. Although the literature on the basic biology and clinical applications of EVs remains wanting, increasing progress is being made in the preclinical setting. Our review highlights relevant studies that have deepened our understanding of these clinical implications and highlighted the limitations of EV applicability and knowledge gaps in critical areas of ILD research (Figure 3).
Biomarkers for ILDs are essential and would offer clinicians the ability to provide evidence-based personalized care to ILD patients. Currently, the application of ILD biomarkers is hindered by the complexity of ILD diagnostic criteria [81,82,119,120,121]. The main obstacles are the sensitivity and specificity of such biomarkers that require high case numbers for statistical validation. A few have been recently explored [81,122]. Uniquely, EVs can carry and preserve cargo, making them a promising target for research. The primary challenges are efficient and reproducible EV isolation protocols. EV isolation by ultracentrifugation followed by purification using a density gradient (UC-SDG) is the current gold standard for obtaining a pure EV preparation. However, this method involves significant loss and requires special equipment (ultracentrifuge), making it costly and impractical. The advancement in EV isolation techniques will certainly accelerate a translation to clinical research and their application as therapeutic agents. Furthermore, the availability of patient-derived EVs for biomarker mining remains extremely limited. Future high throughput analysis of circulating biomarkers in ILDs may include serum- and plasma-derived EVs that could be purified with high yields for comprehensive multi-omics research. Preclinical biomarkers identified from in vitro and in vivo animal models may not be directly applicable to human biology. A comprehensive database of human EV cargo contents from respiratory biological specimens such as BALF or serum is still not well-developed. The reference database is essential in understanding the global changes of cellular functions inside and outside the lung microenvironment, allowing a more accurate integration of disease processes.
The therapeutic promise of EVs as cell-free based therapy is upward trending with high potential as described earlier. Despite clear advantages, specific challenges require further basic research, process and product engineering and development. Undoubtedly, preclinical results have been promising. However, the current lack of standardization of EV isolation, purification, and characterization methods is a major challenge to the translation of therapeutic EVs into clinical studies. Standardization and harmonization of these protocols are vital for the accurate evaluation and demonstration of reproducibility needed for clinical translation [3]. Furthermore, little is known regarding EV kinetics and biodistribution in animal models, and, more so, in human subjects. EV labeling and tracking technologies still have significant limitations including quantifiable and reliable measures of EV tracking in vivo [123,124]. Finally, EV engineering to improve scalability, drug delivery, and therapeutic relevance and potency remain active areas of research and discovery.
In summary, EV research is fast evolving and offers significant promise in the area of ILD therapeutic research, allowing for the clinical utilization of EV in the near future. Effective tools of EV purification, cargo evaluation, tracking, and therapeutic cell sourcing represent the primary objectives for the continued translation of these next-generation regenerative medicine therapeutics.

Author Contributions

Conceptualization, T.P., A.I. (Abdulrahman Ibrahim) and A.I. (Ahmed Ibrahim); resources, T.P.; writing—original draft preparation, T.P., A.I. (Abdulrahman Ibrahim) and A.I. (Ahmed Ibrahim); writing—review and editing, T.P., A.I. (Abdulrahman Ibrahim) and A.I. (Ahmed Ibrahim). All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the National Institute of Health (NIH-NHLBI), grant number 1K08HL141590-01A1 (TP).

Acknowledgments

The authors would like to thank Andrew Chin (Biomedical Sciences and Translational Medicine, Department of Surgery, Cedars-Sinai Medical Center) who provided a critical review of this manuscript. Figure 1, Figure 2 and Figure 3 were created using BioRender.com.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Lederer, D.J.; Martinez, F.J. Idiopathic Pulmonary Fibrosis. N. Engl. J. Med. 2018, 378, 1811–1823. [Google Scholar] [CrossRef]
  2. Antin-Ozerkis, D.; Hinchcliff, M. Connective Tissue Disease-Associated Interstitial Lung Disease: Evaluation and Management. Clin. Chest Med. 2019, 40, 617–636. [Google Scholar] [CrossRef]
  3. Gandham, S.; Su, X.; Wood, J.; Nocera, A.L.; Alli, S.C.; Milane, L.; Zimmerman, A.; Amiji, M.; Ivanov, A.R. Technologies and Standardization in Research on Extracellular Vesicles. Trends Biotechnol. 2020, 38, 1066–1098. [Google Scholar] [CrossRef] [PubMed]
  4. Travis, W.D.; Costabel, U.; Hansell, D.M.; King, T.E.; Lynch, D.A.; Nicholson, A.G.; Ryerson, C.J.; Ryu, J.H.; Selman, M.; Wells, A.U.; et al. An Official American Thoracic Society/European Respiratory Society Statement: Update of the International Multidisciplinary Classification of the Idiopathic Interstitial Pneumonias. Am. J. Respir. Crit. Care Med. 2013, 188, 733–748. [Google Scholar] [CrossRef] [PubMed]
  5. Guler, S.A.; Ellison, K.; Algamdi, M.; Collard, H.R.; Ryerson, C.J. Heterogeneity in Unclassifiable Interstitial Lung Disease. A Systematic Review and Meta-Analysis. Ann. Am. Thorac. Soc. 2018, 15, 854–863. [Google Scholar] [CrossRef] [PubMed]
  6. Ryerson, C.J.; Urbania, T.H.; Richeldi, L.; Mooney, J.J.; Lee, J.S.; Jones, K.D.; Elicker, B.M.; Koth, L.L.; King, T.E., Jr.; Wolters, P.J.; et al. Prevalence and prognosis of unclassifiable interstitial lung disease. Eur. Respir. J. 2013, 42, 750–757. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  7. Khor, Y.H.; Ng, Y.; Barnes, H.; Goh, N.S.L.; McDonald, C.F.; Holland, A.E. Prognosis of idiopathic pulmonary fibrosis without anti-fibrotic therapy: A systematic review. Eur. Respir. Rev. 2020, 29. [Google Scholar] [CrossRef]
  8. Dhooria, S.; Agarwal, R.; Sehgal, I.S.; Prasad, K.T.; Garg, M.; Bal, A.; Aggarwal, A.N.; Behera, D. Spectrum of interstitial lung diseases at a tertiary center in a developing country: A study of 803 subjects. PLoS ONE 2018, 13, e0191938. [Google Scholar] [CrossRef] [Green Version]
  9. Ryerson, C.J.; Corte, T.J.; Lee, J.S.; Richeldi, L.; Walsh, S.L.F.; Myers, J.L.; Behr, J.; Cottin, V.; Danoff, S.K.; Flaherty, K.R.; et al. A Standardized Diagnostic Ontology for Fibrotic Interstitial Lung Disease. An International Working Group Perspective. Am. J. Respir. Crit. Care Med. 2017, 196, 1249–1254. [Google Scholar] [CrossRef]
  10. Distler, O.; Highland, K.B.; Gahlemann, M.; Azuma, A.; Fischer, A.; Mayes, M.D.; Raghu, G.; Sauter, W.; Girard, M.; Alves, M.; et al. Nintedanib for Systemic Sclerosis-Associated Interstitial Lung Disease. N. Engl. J. Med. 2019, 380, 2518–2528. [Google Scholar] [CrossRef]
  11. Wells, A.U.; Flaherty, K.R.; Brown, K.K.; Inoue, Y.; Devaraj, A.; Richeldi, L.; Moua, T.; Crestani, B.; Wuyts, W.A.; Stowasser, S.; et al. Nintedanib in patients with progressive fibrosing interstitial lung diseases-subgroup analyses by interstitial lung disease diagnosis in the INBUILD trial: A randomised, double-blind, placebo-controlled, parallel-group trial. Lancet Respir. Med. 2020, 8, 453–460. [Google Scholar] [CrossRef]
  12. De Sadeleer, L.J.; Verleden, S.E.; Vos, R.; Van Raemdonck, D.; Verleden, G.M. Advances in lung transplantation for interstitial lung diseases. Curr. Opin. Pulm. Med. 2020, 26, 518–525. [Google Scholar] [CrossRef] [PubMed]
  13. Sakamoto, S.; Kataoka, K.; Kondo, Y.; Kato, M.; Okamoto, M.; Mukae, H.; Bando, M.; Suda, T.; Yatera, K.; Tanino, Y.; et al. Pirfenidone plus inhaled N-acetylcysteine for idiopathic pulmonary fibrosis: A randomised trial. Eur. Respir. J. 2020. [Google Scholar] [CrossRef] [PubMed]
  14. Flaherty, K.R.; Wells, A.U.; Cottin, V.; Devaraj, A.; Walsh, S.L.F.; Inoue, Y.; Richeldi, L.; Kolb, M.; Tetzlaff, K.; Stowasser, S.; et al. Nintedanib in Progressive Fibrosing Interstitial Lung Diseases. N. Engl. J. Med. 2019, 381, 1718–1727. [Google Scholar] [CrossRef] [Green Version]
  15. Nathan, S.D.; Albera, C.; Bradford, W.Z.; Costabel, U.; Glaspole, I.; Glassberg, M.K.; Kardatzke, D.R.; Daigl, M.; Kirchgaessler, K.-U.; Lancaster, L.H.; et al. Effect of pirfenidone on mortality: Pooled analyses and meta-analyses of clinical trials in idiopathic pulmonary fibrosis. Lancet Respir. Med. 2017, 5, 33–41. [Google Scholar] [CrossRef]
  16. Rivera-Ortega, P.; Molina-Molina, M. Interstitial Lung Diseases in Developing Countries. Ann. Glob. Health 2019, 85. [Google Scholar] [CrossRef] [Green Version]
  17. Frank, A.L.; Kreuter, M.; Schwarzkopf, L. Economic burden of incident interstitial lung disease (ILD) and the impact of comorbidity on costs of care. Respir. Med. 2019, 152, 25–31. [Google Scholar] [CrossRef]
  18. Antoniou, K.; Kamekis, A.; Symvoulakis, E.K.; Kokosi, M.; Swigris, J.J. Burden of idiopathic pulmonary fibrosis on patients’ emotional well being and quality of life: A literature review. Curr. Opin. Pulm. Med. 2020, 26, 457–463. [Google Scholar] [CrossRef]
  19. Olson, A.L.; Maher, T.M.; Acciai, V.; Mounir, B.; Quaresma, M.; Zouad-Lejour, L.; Wells, C.D.; De Loureiro, L. Healthcare Resources Utilization and Costs of Patients with Non-IPF Progressive Fibrosing Interstitial Lung Disease Based on Insurance Claims in the USA. Adv. Ther. 2020, 37, 3292–3298. [Google Scholar] [CrossRef]
  20. Chanda, D.; Otoupalova, E.; Hough, K.P.; Locy, M.L.; Bernard, K.; Deshane, J.S.; Sanderson, R.D.; Mobley, J.A.; Thannickal, V.J. Fibronectin on the Surface of Extracellular Vesicles Mediates Fibroblast Invasion. Am. J. Respir. Cell Mol. Biol. 2019, 60, 279–288. [Google Scholar] [CrossRef]
  21. Parimon, T.; Yao, C.; Habiel, D.M.; Ge, L.; Bora, S.A.; Brauer, R.; Evans, C.M.; Xie, T.; Alonso-Valenteen, F.; Medina-Kauwe, L.K.; et al. Syndecan-1 promotes lung fibrosis by regulating epithelial reprogramming through extracellular vesicles. JCI Insight 2019, 5. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  22. Worthington, E.N.; Hagood, J.S. Therapeutic Use of Extracellular Vesicles for Acute and Chronic Lung Disease. Int. J. Mol. Sci. 2020, 21, 2318. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  23. Eltom, S.; Dale, N.; Raemdonck, K.R.; Stevenson, C.S.; Snelgrove, R.J.; Sacitharan, P.K.; Recchi, C.; Wavre-Shapton, S.; McAuley, D.F.; O’Kane, C.; et al. Respiratory infections cause the release of extracellular vesicles: Implications in exacerbation of asthma/COPD. PLoS ONE 2014, 9, e101087. [Google Scholar] [CrossRef] [Green Version]
  24. Mohan, A.; Agarwal, S.; Clauss, M.; Britt, N.S.; Dhillon, N.K. Extracellular vesicles: Novel communicators in lung diseases. Respir. Res. 2020, 21, 175. [Google Scholar] [CrossRef]
  25. Feller, D.; Kun, J.; Ruzsics, I.; Rapp, J.; Sarosi, V.; Kvell, K.; Helyes, Z.; Pongracz, J.E. Cigarette Smoke-Induced Pulmonary Inflammation Becomes Systemic by Circulating Extracellular Vesicles Containing Wnt5a and Inflammatory Cytokines. Front. Immunol. 2018, 9, 1724. [Google Scholar] [CrossRef]
  26. Fujita, Y.; Araya, J.; Ito, S.; Kobayashi, K.; Kosaka, N.; Yoshioka, Y.; Kadota, T.; Hara, H.; Kuwano, K.; Ochiya, T. Suppression of autophagy by extracellular vesicles promotes myofibroblast differentiation in COPD pathogenesis. J. Extracell. Vesicles 2015, 4, 28388. [Google Scholar] [CrossRef] [PubMed]
  27. Wilkinson, T. Understanding disease mechanisms at the nanoscale: Endothelial apoptosis and microparticles in COPD. Thorax 2016, 71, 1078–1079. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  28. Chen, T.; Raj, J.U. Extracellular Vesicles, MicroRNAs, and Pulmonary Hypertension; Springer: Singapore, 2020; pp. 71–77. [Google Scholar]
  29. Khandagale, A.; Åberg, M.; Wikström, G.; Lind, S.B.; Shevchenko, G.; Björklund, E.; Siegbahn, A.; Christersson, C. Role of Extracellular Vesicles in Pulmonary Arterial Hypertension. Arterioscler. Thromb. Vasc. Biol. 2020, 40, 2293–2309. [Google Scholar] [CrossRef] [PubMed]
  30. Zaizen, Y.; Kohashi, Y.; Kuroda, K.; Tabata, K.; Kitamura, Y.; Hebisawa, A.; Saito, Y.; Fukuoka, J. Concordance between sequential transbronchial lung cryobiopsy and surgical lung biopsy in patients with diffuse interstitial lung disease. Diagn. Pathol. 2019, 14, 131. [Google Scholar] [CrossRef] [Green Version]
  31. Chami, H.A.; Diaz-Mendoza, J.; Chua, A.; Duggal, A.; Jenkins, A.R.; Knight, S.; Patolia, S.; Tamae-Kakazu, M.; Raghu, G.; Wilson, K.C. Transbronchial Biopsy and Cryobiopsy in the Diagnosis of Hypersensitivity Pneumonitis among Patients with Interstitial Lung Disease. Ann. Am. Thorac. Soc. 2020. [Google Scholar] [CrossRef]
  32. Raghu, G.; Remy-Jardin, M.; Myers, J.L.; Richeldi, L.; Ryerson, C.J.; Lederer, D.J.; Behr, J.; Cottin, V.; Danoff, S.K.; Morell, F.; et al. Diagnosis of Idiopathic Pulmonary Fibrosis. An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline. Am. J. Respir. Crit. Care Med. 2018, 198, e44–e68. [Google Scholar] [CrossRef]
  33. Lener, T.; Gimona, M.; Aigner, L.; Börger, V.; Buzas, E.; Camussi, G.; Chaput, N.; Chatterjee, D.; Court, F.A.; Del Portillo, H.A.; et al. Applying extracellular vesicles based therapeutics in clinical trials—An ISEV position paper. J. Extracell. Vesicles 2015, 4, 30087. [Google Scholar] [CrossRef]
  34. Popowski, K.; Lutz, H.; Hu, S.; George, A.; Dinh, P.-U.; Cheng, K. Exosome therapeutics for lung regenerative medicine. J. Extracell. Vesicles 2020, 9, 1785161. [Google Scholar] [CrossRef]
  35. Romano, M.; Zendrini, A.; Paolini, L.; Busatto, S.; Berardi, A.C.; Bergese, P.; Radeghieri, A. 2—Extracellular vesicles in regenerative medicine. In Nanomaterials for Theranostics and Tissue Engineering; Rossi, F., Rainer, A., Eds.; Elsevier: Amsterdam, The Netherlands, 2020; pp. 29–58. [Google Scholar] [CrossRef]
  36. Murphy, D.E.; de Jong, O.G.; Brouwer, M.; Wood, M.J.; Lavieu, G.; Schiffelers, R.M.; Vader, P. Extracellular vesicle-based therapeutics: Natural versus engineered targeting and trafficking. Exp. Mol. Med. 2019, 51, 1–12. [Google Scholar] [CrossRef] [PubMed]
  37. Wiklander, O.P.B.; Brennan, M.Á.; Lötvall, J.; Breakefield, X.O.; EL Andaloussi, S. Advances in therapeutic applications of extracellular vesicles. Sci. Transl. Med. 2019, 11, eaav8521. [Google Scholar] [CrossRef] [PubMed]
  38. Jimenez, J.J.; Jy, W.; Mauro, L.M.; Soderland, C.; Horstman, L.L.; Ahn, Y.S. Endothelial cells release phenotypically and quantitatively distinct microparticles in activation and apoptosis. Thromb. Res. 2003, 109, 175c180. [Google Scholar] [CrossRef]
  39. Hou, P.-P.; Luo, L.-J.; Chen, H.-Z.; Chen, Q.-T.; Bian, X.-L.; Wu, S.-F.; Zhou, J.-X.; Zhao, W.-X.; Liu, J.-M.; Wang, X.-M.; et al. Ectosomal PKM2 Promotes HCC by Inducing Macrophage Differentiation and Remodeling the Tumor Microenvironment. Mol. Cell 2020, 78, 1192–1206. [Google Scholar] [CrossRef]
  40. Yokoi, A.; Villar-Prados, A.; Oliphint, P.A.; Zhang, J.; Song, X.; De Hoff, P.; Morey, R.; Liu, J.; Roszik, J.; Clise-Dwyer, K.; et al. Mechanisms of nuclear content loading to exosomes. Sci. Adv. 2019, 5, eaax8849. [Google Scholar] [CrossRef] [Green Version]
  41. Jeppesen, D.K.; Fenix, A.M.; Franklin, J.L.; Higginbotham, J.N.; Zhang, Q.; Zimmerman, L.J.; Liebler, D.C.; Ping, J.; Liu, Q.; Evans, R.; et al. Reassessment of Exosome Composition. Cell 2019, 177, 428–445. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  42. Pan, B.-T.; Johnstone, R.M. Fate of the transferrin receptor during maturation of sheep reticulocytes in vitro: Selective externalization of the receptor. Cell 1983, 33, 967–978. [Google Scholar] [CrossRef]
  43. Harding, C.; Stahl, P. Transferrin recycling in reticulocytes: pH and iron are important determinants of ligand binding and processing. Biochem. Biophys. Res. Commun. 1983, 113, 650–658. [Google Scholar] [CrossRef]
  44. Shah, R.; Patel, T.; Freedman, J.E. Circulating Extracellular Vesicles in Human Disease. N. Engl. J. Med. 2018, 379, 958–966. [Google Scholar] [CrossRef] [PubMed]
  45. Jansen, F.; Nickenig, G.; Werner, N. Extracellular Vesicles in Cardiovascular Disease: Potential Applications in Diagnosis, Prognosis, and Epidemiology. Circ. Res. 2017, 120, 1649–1657. [Google Scholar] [CrossRef] [PubMed]
  46. McVey, M.J.; Maishan, M.; Blokland, K.E.C.; Bartlett, N.; Kuebler, W.M. Extracellular vesicles in lung health, disease, and therapy. Am. J. Physiol. Lung Cell. Mol. Physiol. 2019, 316, L977–L989. [Google Scholar] [CrossRef]
  47. Minciacchi, V.R.; Freeman, M.R.; Di Vizio, D. Extracellular vesicles in cancer: Exosomes, microvesicles and the emerging role of large oncosomes. Semin. Cell Dev. Biol. 2015, 40, 41–51. [Google Scholar] [CrossRef] [Green Version]
  48. Szabo, G.; Momen-Heravi, F. Extracellular vesicles in liver disease and potential as biomarkers and therapeutic targets. Nat. Rev. Gastroenterol. Hepatol. 2017, 14, 455–466. [Google Scholar] [CrossRef]
  49. Yáñez-Mó, M.; Siljander, P.R.M.; Andreu, Z.; Zavec, A.B.; Borràs, F.E.; Buzas, E.I.; Buzas, K.; Casal, E.; Cappello, F.; Carvalho, J.; et al. Biological properties of extracellular vesicles and their physiological functions. J. Extracell. Vesicles 2015, 4, 27066. [Google Scholar] [CrossRef] [Green Version]
  50. Valadi, H.; Ekström, K.; Bossios, A.; Sjöstrand, M.; Lee, J.J.; Lötvall, J.O. Exosome-mediated transfer of mRNAs and microRNAs is a novel mechanism of genetic exchange between cells. Nat. Cell Biol. 2007, 9, 654–659. [Google Scholar] [CrossRef] [Green Version]
  51. Kalluri, R.; LeBleu, V.S. The biology, function, and biomedical applications of exosomes. Science 2020, 367, eaau6977. [Google Scholar] [CrossRef]
  52. Cruz, L.; Romero, J.A.A.; Iglesia, R.P.; Lopes, M.H. Extracellular Vesicles: Decoding a New Language for Cellular Communication in Early Embryonic Development. Front. Cell Dev. Biol. 2018, 6, 94. [Google Scholar] [CrossRef]
  53. Stahl, P.D.; Raposo, G. Extracellular Vesicles: Exosomes and Microvesicles, Integrators of Homeostasis. Physiology 2019, 34, 169–177. [Google Scholar] [CrossRef] [PubMed]
  54. Alderton, G.K. Metastasis. Exosomes drive premetastatic niche formation. Nat. Rev. Cancer 2012, 12, 447. [Google Scholar] [CrossRef] [PubMed]
  55. Di Vizio, D.; Morello, M.; Dudley, A.C.; Schow, P.W.; Adam, R.M.; Morley, S.; Mulholland, D.; Rotinen, M.; Hager, M.H.; Insabato, L.; et al. Large oncosomes in human prostate cancer tissues and in the circulation of mice with metastatic disease. Am. J. Pathol. 2012, 181, 1573–1584. [Google Scholar] [CrossRef] [PubMed]
  56. Peinado, H.; Alečković, M.; Lavotshkin, S.; Matei, I.; Costa-Silva, B.; Moreno-Bueno, G.; Hergueta-Redondo, M.; Williams, C.; García-Santos, G.; Ghajar, C.; et al. Melanoma exosomes educate bone marrow progenitor cells toward a pro-metastatic phenotype through MET. Nat. Med. 2012, 18, 883–891. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  57. Bagnato, G.; Harari, S. Cellular interactions in the pathogenesis of interstitial lung diseases. Eur. Respir. Rev. 2015, 24, 102–114. [Google Scholar] [CrossRef]
  58. Bartel, S.; Deshane, J.; Wilkinson, T.; Gabrielsson, S. Extracellular Vesicles as Mediators of Cellular Cross Talk in the Lung Microenvironment. Front. Med. 2020, 7, 326. [Google Scholar] [CrossRef]
  59. Lee, H.; Abston, E.; Zhang, D.; Rai, A.; Jin, Y. Extracellular Vesicle: An Emerging Mediator of Intercellular Crosstalk in Lung Inflammation and Injury. Front. Immunol. 2018, 9. [Google Scholar] [CrossRef]
  60. Soni, S.; Wilson, M.R.; O’Dea, K.P.; Yoshida, M.; Katbeh, U.; Woods, S.J.; Takata, M. Alveolar macrophage-derived microvesicles mediate acute lung injury. Thorax 2016, 71, 1020–1029. [Google Scholar] [CrossRef] [Green Version]
  61. Ye, C.; Li, H.; Bao, M.; Zhuo, R.; Jiang, G.; Wang, W. Alveolar macrophage—Derived exosomes modulate severity and outcome of acute lung injury. Aging 2020, 12, 6120–6128. [Google Scholar] [CrossRef]
  62. Admyre, C.; Grunewald, J.; Thyberg, J.; Gripenbäck, S.; Tornling, G.; Eklund, A.; Scheynius, A.; Gabrielsson, S. Exosomes with major histocompatibility complex class II and co-stimulatory molecules are present in human BAL fluid. Eur. Respir. J. 2003, 22, 578–583. [Google Scholar] [CrossRef]
  63. Nana-Sinkam, S.P.; Acunzo, M.; Croce, C.M.; Wang, K. Extracellular Vesicle Biology in the Pathogenesis of Lung Disease. Am. J. Respir. Crit. Care Med. 2017, 196, 1510–1518. [Google Scholar] [CrossRef] [PubMed]
  64. Holtzman, J.; Lee, H. Emerging role of extracellular vesicles in the respiratory system. Exp. Mol. Med. 2020, 52, 887–895. [Google Scholar] [CrossRef] [PubMed]
  65. Skeoch, S.; Weatherley, N.; Swift, A.J.; Oldroyd, A.; Johns, C.; Hayton, C.; Giollo, A.; Wild, J.M.; Waterton, J.C.; Buch, M.; et al. Drug-Induced Interstitial Lung Disease: A Systematic Review. J. Clin. Med. 2018, 7, 356. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  66. Novelli, F.; Neri, T.; Tavanti, L.; Armani, C.; Noce, C.; Falaschi, F.; Bartoli, M.L.; Martino, F.; Palla, A.; Celi, A.; et al. Procoagulant, tissue factor-bearing microparticles in bronchoalveolar lavage of interstitial lung disease patients: An observational study. PLoS ONE 2014, 9, e95013. [Google Scholar] [CrossRef] [PubMed]
  67. Qazi, K.R.; Torregrosa Paredes, P.; Dahlberg, B.; Grunewald, J.; Eklund, A.; Gabrielsson, S. Proinflammatory exosomes in bronchoalveolar lavage fluid of patients with sarcoidosis. Thorax 2010, 65, 1016–1024. [Google Scholar] [CrossRef] [Green Version]
  68. Martinez-Bravo, M.J.; Wahlund, C.J.; Qazi, K.R.; Moulder, R.; Lukic, A.; Rådmark, O.; Lahesmaa, R.; Grunewald, J.; Eklund, A.; Gabrielsson, S. Pulmonary sarcoidosis is associated with exosomal vitamin D-binding protein and inflammatory molecules. J. Allergy Clin. Immunol. 2017, 139, 1186–1194. [Google Scholar] [CrossRef] [Green Version]
  69. Wahlund, C.J.E.; Gucluler Akpinar, G.; Steiner, L.; Ibrahim, A.; Bandeira, E.; Lepzien, R.; Lukic, A.; Smed-Sörensen, A.; Kullberg, S.; Eklund, A.; et al. Sarcoidosis exosomes stimulate monocytes to produce pro-inflammatory cytokines and CCL2. Sci. Rep. 2020, 10, 15328. [Google Scholar] [CrossRef]
  70. Adams, T.S.; Schupp, J.C.; Poli, S.; Ayaub, E.A.; Neumark, N.; Ahangari, F.; Chu, S.G.; Raby, B.A.; DeIuliis, G.; Januszyk, M.; et al. Single-cell RNA-seq reveals ectopic and aberrant lung-resident cell populations in idiopathic pulmonary fibrosis. Sci. Adv. 2020, 6, eaba1983. [Google Scholar] [CrossRef]
  71. Reyfman, P.A.; Walter, J.M.; Joshi, N.; Anekalla, K.R.; McQuattie-Pimentel, A.C.; Chiu, S.; Fernandez, R.; Akbarpour, M.; Chen, C.I.; Ren, Z.; et al. Single-Cell Transcriptomic Analysis of Human Lung Provides Insights into the Pathobiology of Pulmonary Fibrosis. Am. J. Respir. Crit. Care Med. 2019, 199, 1517–1536. [Google Scholar] [CrossRef]
  72. Kang, J.H.; Jung, M.Y.; Choudhury, M.; Leof, E.B. Transforming growth factor beta induces fibroblasts to express and release the immunomodulatory protein PD-L1 into extracellular vesicles. FASEB J. 2020, 34, 2213–2226. [Google Scholar] [CrossRef] [Green Version]
  73. Guiot, J.; Cambier, M.; Boeckx, A.; Henket, M.; Nivelles, O.; Gester, F.; Louis, E.; Malaise, M.; Dequiedt, F.; Louis, R.; et al. Macrophage-derived exosomes attenuate fibrosis in airway epithelial cells through delivery of antifibrotic miR-142-3p. Thorax 2020, 75, 870–881. [Google Scholar] [CrossRef] [PubMed]
  74. Lacy, S.H.; Woeller, C.F.; Thatcher, T.H.; Pollock, S.J.; Small, E.M.; Sime, P.J.; Phipps, R.P. Activated Human Lung Fibroblasts Produce Extracellular Vesicles with Antifibrotic Prostaglandins. Am. J. Respir. Cell Mol. Biol. 2019, 60, 269–278. [Google Scholar] [CrossRef]
  75. Martin-Medina, A.; Lehmann, M.; Burgy, O.; Hermann, S.; Baarsma, H.A.; Wagner, D.E.; De Santis, M.M.; Ciolek, F.; Hofer, T.P.; Frankenberger, M.; et al. Increased Extracellular Vesicles Mediate WNT5A Signaling in Idiopathic Pulmonary Fibrosis. Am. J. Respir. Crit. Care Med. 2018, 198, 1527–1538. [Google Scholar] [CrossRef] [PubMed]
  76. Gradl, D.; Kühl, M.; Wedlich, D. The Wnt/Wg signal transducer beta-catenin controls fibronectin expression. Mol. Cell. Biol. 1999, 19, 5576–5587. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  77. Barnes, P.J.; Baker, J.; Donnelly, L.E. Cellular Senescence as a Mechanism and Target in Chronic Lung Diseases. Am. J. Respir. Crit. Care Med. 2019, 200, 556–564. [Google Scholar] [CrossRef]
  78. Schafer, M.J.; White, T.A.; Iijima, K.; Haak, A.J.; Ligresti, G.; Atkinson, E.J.; Oberg, A.L.; Birch, J.; Salmonowicz, H.; Zhu, Y.; et al. Cellular senescence mediates fibrotic pulmonary disease. Nat. Commun. 2017, 8, 14532. [Google Scholar] [CrossRef]
  79. Kadota, T.; Fujita, Y.; Yoshioka, Y.; Araya, J.; Kuwano, K.; Ochiya, T. Emerging role of extracellular vesicles as a senescence-associated secretory phenotype: Insights into the pathophysiology of lung diseases. Mol. Asp. Med. 2018, 60, 92–103. [Google Scholar] [CrossRef]
  80. Kadota, T.; Yoshioka, Y.; Fujita, Y.; Araya, J.; Minagawa, S.; Hara, H.; Miyamoto, A.; Suzuki, S.; Fujimori, S.; Kohno, T.; et al. Extracellular Vesicles from Fibroblasts Induce Epithelial Cell Senescence in Pulmonary Fibrosis. Am. J. Respir. Cell Mol. Biol. 2020. [Google Scholar] [CrossRef]
  81. Guiot, J.; Moermans, C.; Henket, M.; Corhay, J.-L.; Louis, R. Blood Biomarkers in Idiopathic Pulmonary Fibrosis. Lung 2017, 195, 273–280. [Google Scholar] [CrossRef] [Green Version]
  82. Ley, B.; Brown, K.K.; Collard, H.R. Molecular biomarkers in idiopathic pulmonary fibrosis. Am. J. Physiol. Lung Cell. Mol. Physiol. 2014, 307, L681–L691. [Google Scholar] [CrossRef]
  83. Yang, D.; Zhang, W.; Zhang, H.; Zhang, F.; Chen, L.; Ma, L.; Larcher, L.M.; Chen, S.; Liu, N.; Zhao, Q.; et al. Progress, opportunity, and perspective on exosome isolation—Efforts for efficient exosome-based theranostics. Theranostics 2020, 10, 3684–3707. [Google Scholar] [CrossRef] [PubMed]
  84. Yang, G.; Yang, L.; Wang, W.; Wang, J.; Wang, J.; Xu, Z. Discovery and validation of extracellular/circulating microRNAs during idiopathic pulmonary fibrosis disease progression. Gene 2015, 562, 138–144. [Google Scholar] [CrossRef] [PubMed]
  85. Minnis, P.; Kane, R.; Anglin, R.; Walsh, S.M.; Worrel, J.; Khan, F.; Lumsden, R.V.; Whitty, S.; Keane, M. Serum exosomes from IPF patients display a fibrotic miRNA profile that correlates to clinical measures of disease severity. Eur. Respir. J. 2015, 46, PA3845. [Google Scholar]
  86. Makiguchi, T.; Yamada, M.; Yoshioka, Y.; Sugiura, H.; Koarai, A.; Chiba, S.; Fujino, N.; Tojo, Y.; Ota, C.; Kubo, H.; et al. Serum extracellular vesicular miR-21-5p is a predictor of the prognosis in idiopathic pulmonary fibrosis. Respir. Res. 2016, 17, 110. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  87. Go, H.; Maeda, H.; Miyazaki, K.; Maeda, R.; Kume, Y.; Namba, F.; Momoi, N.; Hashimoto, K.; Otsuru, S.; Kawasaki, Y.; et al. Extracellular vesicle miRNA-21 is a potential biomarker for predicting chronic lung disease in premature infants. Am. J. Physiol. Lung Cell. Mol. Physiol. 2020, 318, L845–L851. [Google Scholar] [CrossRef] [PubMed]
  88. Njock, M.S.; Guiot, J.; Henket, M.A.; Nivelles, O.; Thiry, M.; Dequiedt, F.; Corhay, J.L.; Louis, R.E.; Struman, I. Sputum exosomes: Promising biomarkers for idiopathic pulmonary fibrosis. Thorax 2019, 74, 309–312. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  89. Neri, T.; Tavanti, L.; De Magistris, S.; Lombardi, S.; Romei, C.; Falaschi, F.; Paggiaro, P.; Celi, A. Endothelial Cell-Derived Extracellular Vesicles as Potential Biomarkers in Chronic Interstitial Lung Diseases. Ann. Clin. Lab. Sci. 2019, 49, 608–610. [Google Scholar]
  90. Wan, X.; Chen, S.; Fang, Y.; Zuo, W.; Cui, J.; Xie, S. Mesenchymal stem cell-derived extracellular vesicles suppress the fibroblast proliferation by downregulating FZD6 expression in fibroblasts via micrRNA-29b-3p in idiopathic pulmonary fibrosis. J. Cell. Physiol. 2020. [Google Scholar] [CrossRef]
  91. Lei, X.; He, N.; Zhu, L.; Zhou, M.; Zhang, K.; Wang, C.; Huang, H.; Chen, S.; Li, Y.; Liu, Q.; et al. Mesenchymal Stem Cell-Derived Extracellular Vesicles Attenuate Radiation-Induced Lung Injury via miRNA-214-3p. Antioxid. Redox Signal. 2020. [Google Scholar] [CrossRef]
  92. Mansouri, N.; Willis, G.R.; Fernandez-Gonzalez, A.; Reis, M.; Nassiri, S.; Mitsialis, S.A.; Kourembanas, S. Mesenchymal stromal cell exosomes prevent and revert experimental pulmonary fibrosis through modulation of monocyte phenotypes. JCI Insight 2019, 4, e128060. [Google Scholar] [CrossRef] [Green Version]
  93. Dinh, P.C.; Paudel, D.; Brochu, H.; Popowski, K.D.; Gracieux, M.C.; Cores, J.; Huang, K.; Hensley, M.T.; Harrell, E.; Vandergriff, A.C.; et al. Inhalation of lung spheroid cell secretome and exosomes promotes lung repair in pulmonary fibrosis. Nat. Commun. 2020, 11, 1064. [Google Scholar] [CrossRef] [PubMed]
  94. Gao, Y.; Sun, J.; Dong, C.; Zhao, M.; Hu, Y.; Jin, F. Extracellular Vesicles Derived from Adipose Mesenchymal Stem Cells Alleviate PM2.5-Induced Lung Injury and Pulmonary Fibrosis. Med. Sci. Monit. 2020, 26, e922782. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  95. Marbán, E. The Secret Life of Exosomes: What Bees Can Teach Us About Next-Generation Therapeutics. J. Am. Coll. Cardiol. 2018, 71, 193–200. [Google Scholar] [CrossRef] [PubMed]
  96. Tan, J.L.; Lau, S.N.; Leaw, B.; Nguyen, H.P.T.; Salamonsen, L.A.; Saad, M.I.; Chan, S.T.; Zhu, D.; Krause, M.; Kim, C.; et al. Amnion Epithelial Cell-Derived Exosomes Restrict Lung Injury and Enhance Endogenous Lung Repair. Stem Cells Transl. Med. 2018, 7, 180–196. [Google Scholar] [CrossRef] [Green Version]
  97. Stolzenburg, L.R.; Harris, A. Microvesicle-mediated delivery of miR-1343: Impact on markers of fibrosis. Cell Tissue Res. 2018, 371, 325–338. [Google Scholar] [CrossRef]
  98. Shentu, T.P.; Wong, S.; Espinoza, C.; Cernelc-Kohan, M.; Hagood, J. Extracellular vesicles isolated from human mesenchymal stem cells promote resolution of pulmonary fibrosis. FASEB J. 2016, 30, 160–162. [Google Scholar] [CrossRef]
  99. Ibrahim, A.G.-E.; Cheng, K.; Marbán, E. Exosomes as Critical Agents of Cardiac Regeneration Triggered by Cell Therapy. Stem Cell Rep. 2014, 2, 606–619. [Google Scholar] [CrossRef] [Green Version]
  100. Wang, J.; Huang, W.; Xu, R.; Nie, Y.; Cao, X.; Meng, J.; Xu, X.; Hu, S.; Zheng, Z. MicroRNA-24 regulates cardiac fibrosis after myocardial infarction. J. Cell. Mol. Med. 2012, 16, 2150–2160. [Google Scholar] [CrossRef]
  101. Royce, S.G.; Patel, K.P.; Mao, W.; Zhu, D.; Lim, R.; Samuel, C.S. Serelaxin enhances the therapeutic effects of human amnion epithelial cell-derived exosomes in experimental models of lung disease. Br. J. Pharmacol. 2019, 176, 2195–2208. [Google Scholar] [CrossRef]
  102. Jafari, D.; Shajari, S.; Jafari, R.; Mardi, N.; Gomari, H.; Ganji, F.; Forouzandeh Moghadam, M.; Samadikuchaksaraei, A. Designer Exosomes: A New Platform for Biotechnology Therapeutics. BioDrugs 2020, 34, 567–586. [Google Scholar] [CrossRef]
  103. Li, Y.-J.; Wu, J.-Y.; Wang, J.-M.; Hu, X.-B.; Xiang, D.-X. Emerging strategies for labeling and tracking of extracellular vesicles. J. Control. Release 2020, 328, 141–159. [Google Scholar] [CrossRef] [PubMed]
  104. Tsintou, M.; Dalamagkas, K.; Moore, T.; Rathi, Y.; Kubicki, M.; Rosene, D.; Makris, N. The use of hydrogel-delivered extracellular vesicles in recovery of motor function in stroke: A testable experimental hypothesis for clinical translation including behavioral and neuroimaging assessment approaches. Neural Regen. Res. 2021, 16, 605–613. [Google Scholar] [CrossRef]
  105. Majid, Q.A.; Fricker, A.T.R.; Gregory, D.A.; Davidenko, N.; Hernandez Cruz, O.; Jabbour, R.J.; Owen, T.J.; Basnett, P.; Lukasiewicz, B.; Stevens, M.; et al. Natural Biomaterials for Cardiac Tissue Engineering: A Highly Biocompatible Solution. Front. Cardiovasc. Med. 2020, 7. [Google Scholar] [CrossRef] [PubMed]
  106. Antes, T.J.; Middleton, R.C.; Luther, K.M.; Ijichi, T.; Peck, K.A.; Liu, W.J.; Valle, J.; Echavez, A.K.; Marbán, E. Targeting extracellular vesicles to injured tissue using membrane cloaking and surface display. J. Nanobiotechnol. 2018, 16, 61. [Google Scholar] [CrossRef]
  107. Chen, T.S.; Arslan, F.; Yin, Y.; Tan, S.S.; Lai, R.C.; Choo, A.B.H.; Padmanabhan, J.; Lee, C.N.; de Kleijn, D.P.V.; Lim, S.K. Enabling a robust scalable manufacturing process for therapeutic exosomes through oncogenic immortalization of human ESC-derived MSCs. J. Transl. Med. 2011, 9, 47. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  108. Ibrahim, A.G.E.; Li, C.; Rogers, R.; Fournier, M.; Li, L.; Vaturi, S.D.; Antes, T.; Sanchez, L.; Akhmerov, A.; Moseley, J.J.; et al. Augmenting canonical Wnt signalling in therapeutically inert cells converts them into therapeutically potent exosome factories. Nat. Biomed. Eng. 2019, 3, 695–705. [Google Scholar] [CrossRef] [PubMed]
  109. Yu, B.; Kim, H.W.; Gong, M.; Wang, J.; Millard, R.W.; Wang, Y.; Ashraf, M.; Xu, M. Exosomes secreted from GATA-4 overexpressing mesenchymal stem cells serve as a reservoir of anti-apoptotic microRNAs for cardioprotection. Int. J. Cardiol. 2015, 182, 349–360. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  110. Kanuma, T.; Yamamoto, T.; Kobiyama, K.; Moriishi, E.; Masuta, Y.; Kusakabe, T.; Ozasa, K.; Kuroda, E.; Jounai, N.; Ishii, K.J. CD63-Mediated Antigen Delivery into Extracellular Vesicles via DNA Vaccination Results in Robust CD8+ T Cell Responses. J. Immunol. 2017, 198, 4707–4715. [Google Scholar] [CrossRef] [Green Version]
  111. Li, Z.; Zhou, X.; Gao, X.; Bai, D.; Dong, Y.; Sun, W.; Zhao, L.; Wei, M.; Yang, X.; Yang, G.; et al. Fusion protein engineered exosomes for targeted degradation of specific RNAs in lysosomes: A proof-of-concept study. J. Extracell. Vesicles 2020, 9, 1816710. [Google Scholar] [CrossRef]
  112. Ibrahim, A.; Marbán, E. Exosomes: Fundamental Biology and Roles in Cardiovascular Physiology. Annu. Rev. Physiol. 2016, 78, 67–83. [Google Scholar] [CrossRef] [Green Version]
  113. Anticoli, S.; Manfredi, F.; Chiozzini, C.; Arenaccio, C.; Olivetta, E.; Ferrantelli, F.; Capocefalo, A.; Falcone, E.; Ruggieri, A.; Federico, M. An Exosome-Based Vaccine Platform Imparts Cytotoxic T Lymphocyte Immunity Against Viral Antigens. Biotechnol. J. 2018, 13, 1700443. [Google Scholar] [CrossRef] [PubMed]
  114. Richardson, J.J.; Ejima, H. Surface Engineering of Extracellular Vesicles through Chemical and Biological Strategies. Chem. Mater. 2019, 31, 2191–2201. [Google Scholar] [CrossRef]
  115. Luan, X.; Sansanaphongpricha, K.; Myers, I.; Chen, H.; Yuan, H.; Sun, D. Engineering exosomes as refined biological nanoplatforms for drug delivery. Acta Pharmacol. Sin. 2017, 38, 754–763. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  116. Groot, M.; Lee, H. Sorting Mechanisms for MicroRNAs into Extracellular Vesicles and Their Associated Diseases. Cells 2020, 9, 1044. [Google Scholar] [CrossRef] [PubMed]
  117. Sdrimas, K.; Kourembanas, S. MSC Microvesicles for the Treatment of Lung Disease: A New Paradigm for Cell-Free Therapy. Antioxid. Redox Signal. 2014, 21, 1905–1915. [Google Scholar] [CrossRef] [Green Version]
  118. Gowen, A.; Shahjin, F.; Chand, S.; Odegaard, K.E.; Yelamanchili, S.V. Mesenchymal Stem Cell-Derived Extracellular Vesicles: Challenges in Clinical Applications. Front. Cell Dev. Biol. 2020, 8, 149. [Google Scholar] [CrossRef] [Green Version]
  119. De Lauretis, A.; Renzoni, E.A. Molecular Biomarkers in Interstitial Lung Diseases. Mol. Diagn. Ther. 2014, 18, 505–522. [Google Scholar] [CrossRef]
  120. Alqalyoobi, S.; Adegunsoye, A.; Linderholm, A.; Hrusch, C.; Cutting, C.; Ma, S.F.; Sperling, A.; Noth, I.; Strek, M.E.; Oldham, J.M. Circulating Plasma Biomarkers of Progressive Interstitial Lung Disease. Am. J. Respir. Crit. Care Med. 2020, 201, 250–253. [Google Scholar] [CrossRef]
  121. Fernandez, I.E.; Eickelberg, O. Biomarkers in Interstitial Lung Diseases. In Precision in Pulmonary, Critical Care, and Sleep Medicine; Gomez, J.L., Himes, B.E., Kaminski, N., Eds.; Humana: Cham, Switzerland, 2020; pp. 155–165. [Google Scholar] [CrossRef]
  122. Elhai, M.; Avouac, J.; Allanore, Y. Circulating lung biomarkers in idiopathic lung fibrosis and interstitial lung diseases associated with connective tissue diseases: Where do we stand? Semin. Arthritis Rheum. 2020, 50, 480–491. [Google Scholar] [CrossRef]
  123. Gupta, D.; Liang, X.; Pavlova, S.; Wiklander, O.P.B.; Corso, G.; Zhao, Y.; Saher, O.; Bost, J.; Zickler, A.M.; Piffko, A.; et al. Quantification of extracellular vesicles in vitro and in vivo using sensitive bioluminescence imaging. J. Extracell. Vesicles 2020, 9, 1800222. [Google Scholar] [CrossRef]
  124. Verweij, F.J.; Revenu, C.; Arras, G.; Dingli, F.; Loew, D.; Pegtel, D.M.; Follain, G.; Allio, G.; Goetz, J.G.; Zimmermann, P.; et al. Live Tracking of Inter-organ Communication by Endogenous Exosomes In Vivo. Dev. Cell 2019, 48, 573–589. [Google Scholar] [CrossRef] [PubMed] [Green Version]
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Figure 1. Extracellular vesicles regulate profibrotic signaling pathways in interstitial lung disease pathogenesis. Major profibrotic pathways are regulated by extracellular vesicles’ (EVs) cargo molecules in driving the principal pathways of lung fibroproliferative diseases. Arrows pointing up reflect upregulation and arrows pointing down signify downregulation.
Figure 1. Extracellular vesicles regulate profibrotic signaling pathways in interstitial lung disease pathogenesis. Major profibrotic pathways are regulated by extracellular vesicles’ (EVs) cargo molecules in driving the principal pathways of lung fibroproliferative diseases. Arrows pointing up reflect upregulation and arrows pointing down signify downregulation.
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Figure 2. The schematic illustrates the engineering and production of extracellular vesicles.
Figure 2. The schematic illustrates the engineering and production of extracellular vesicles.
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Figure 3. Extracellular vesicles in interstitial lung diseases. The secretion of pathologic EVs from the injured and fibrotic microenvironment, principally inflammatory cells, epithelial cells, activated fibroblasts, and myofibroblasts triggers further damage in local and distant healthy tissue. Identifying the signals carried by these EVs aids in the development of diagnostic tools to diagnose and track disease progression. EVs derived from therapeutic cell types can also be used to reverse disease phenotype through tissue immunomodulation and tissue repair.
Figure 3. Extracellular vesicles in interstitial lung diseases. The secretion of pathologic EVs from the injured and fibrotic microenvironment, principally inflammatory cells, epithelial cells, activated fibroblasts, and myofibroblasts triggers further damage in local and distant healthy tissue. Identifying the signals carried by these EVs aids in the development of diagnostic tools to diagnose and track disease progression. EVs derived from therapeutic cell types can also be used to reverse disease phenotype through tissue immunomodulation and tissue repair.
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Table
Table 1. Preclinical therapeutic application of EVs in interstitial lung diseases and fibrosis.
Table 1. Preclinical therapeutic application of EVs in interstitial lung diseases and fibrosis.
Experimental Lung Fibrosis ModelEV SourceEV–CargoesOutcomesReference
BleomycinBMSCmiR-29-3pLung fibrosis *[90]
RadiationMSCmiR-214-3pLung injury, Lung fibrosis *[91]
BleomycinBone-MSCunknownLung fibrosis *[92]
Bleomycin, SilicaMSCmiR-10a, miR-99, let-7, MMP2, TIMPLung fibrosis *[93]
PM < 2.5 µmADSClet-7d-5pHistology[94]
SilicaADSCunknownLung fibrosis *, lung compliance[95]
BleomycinAmnion epithelial cellsunknownLung fibrosis *[96]
BleomycinAmnion epithelial cellsunknownLung fibrosis *, lung compliance[97]
* Lung fibrosis was quantitated by hydroxyproline or collagen content, and/or Ashcroft score. BMSC = Bone marrow-derived mesenchymal stem cells; MSC = mesenchymal stem cells; MMP = metalloproteinase; TIMP = tissue inhibitor of metalloproteinase; PM = particle matters; ADSC = adipose mesenchymal stem cells.
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Ibrahim, A.; Ibrahim, A.; Parimon, T. Diagnostic and Therapeutic Applications of Extracellular Vesicles in Interstitial Lung Diseases. Diagnostics 2021, 11, 87. https://doi.org/10.3390/diagnostics11010087

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Ibrahim A, Ibrahim A, Parimon T. Diagnostic and Therapeutic Applications of Extracellular Vesicles in Interstitial Lung Diseases. Diagnostics. 2021; 11(1):87. https://doi.org/10.3390/diagnostics11010087

Chicago/Turabian Style

Ibrahim, Abdulrahman, Ahmed Ibrahim, and Tanyalak Parimon. 2021. "Diagnostic and Therapeutic Applications of Extracellular Vesicles in Interstitial Lung Diseases" Diagnostics 11, no. 1: 87. https://doi.org/10.3390/diagnostics11010087

APA Style

Ibrahim, A., Ibrahim, A., & Parimon, T. (2021). Diagnostic and Therapeutic Applications of Extracellular Vesicles in Interstitial Lung Diseases. Diagnostics, 11(1), 87. https://doi.org/10.3390/diagnostics11010087

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