Exosomal microRNA-21 derived from bronchial epithelial cells is involved in aberrant epithelium-fibroblast cross-talk in COPD induced by cigarette smoking

Exosome microRNA-125a-5p derived from epithelium promotes M1 macrophage polarization by targeting IL1RN in chronic obstructive pulmonary disease

BACKGROUND

The interplay between airway epithelium and macrophages plays a pivotal role in Chronic Obstructive Pulmonary Disease (COPD) pathogenesis. Exosomes, which transport miRNA cargo, have emerged as novel mediators of intercellular communication. MicroRNA-125a-5p (miR-125a-5p) has been implicated in macrophage polarization.This study aims to investigate the role of exosomal miR-125a-5p in the dysfunctional epithelium-macrophage cross-talk in cigarette smoke (CS)-induced COPD.

METHODS

In cell models, THP-1 monocytic cells were differentiated into macrophages (M0). Human bronchial epithelial cells treated with CS extract (CSE) were co-cultured with M0. Exosomes were isolated from culture media using commercial kits and characterized using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Exosomes labeled with PKH26 red fluorescent cell linker kits were incubated with macrophages. Luciferase reporter assay was used to confirm the target gene of miR-125a-5p. In mouse experiments, inhibiting miR-125a-5p was utilized to examine its role in macrophage polarization. Furthermore, the underlying mechanism was explored.

RESULTS

In vitro results indicated that CSE treatment led to upregulation of miR-125a-5p in HBE cells, and exosomes contained miR-125a-5p. PKH26-labeled exosomes were internalized by macrophages. Co-culture experiments between bronchial epithelial cells and miR-125a-5p mimic resulted in significant increase in M1 macrophage markers (TNF-α, iNOS-2, IL-1β) and decrease in M2 markers (IL-10 and Arg-1). In COPD mouse models, miR-125a-5p inhibitor reduced levels of TNF-α, IL-1β, and IL-6. Luciferase assays revealed that miR-125a-5p inhibitors enhanced the relative luciferase activity of IL1RN. Mechanistic experiments demonstrated that HBE-derived exosomes transfected with miR-125a-5p mimics promoted upregulation of MyD88, TRAF6, p65, iNOS-2, and downregulation of Arg-1.

CONCLUSION

This study suggests that exosomal miR-125a-5p may act as a mediator in the cross-talk between airway epithelium and macrophage polarization in COPD. Exosomal miR-125a-5p targeting IL1RN may promote M1 macrophage polarization via the MyD88/NF-κB pathway.

ceRNA Network Analysis Reveals Potential Key miRNAs and Target Genes in COVID-19-Related Chronic Obstructive Pulmonary Disease

The continued spread of SARS-CoV-2 has presented unprecedented obstacles to the worldwide public health system. Especially, individuals with chronic obstructive pulmonary disease (COPD) are at a heightened risk of contracting SARS-CoV-2 infection due to their pre-existing respiratory symptoms that are not well-managed. However, the viral mechanism of affecting the expression of host genes, COPD progression, and prognosis is not clear yet.This study integrated the differential expression information of COPD patients and then calculated the correlation between mRNAs and miRNAs to construct a COPD-specific ceRNA network. The DEGs of individuals with SARS-CoV-2 infection and anticipated miRNAs and their targets were analyzed in 9 SARS-CoV-2 sequences from different geographic locations. Furthermore, combining the experimentally validated miRNAs and genes, the regulatory miRNA-mRNA relationships were identified. All the regulatory relationships were integrated into the COPD-specific network and the network modules were explored to get insight into the functional mechanism of SARS-CoV-2 infection in COPD patients.A higher proportion of DEGs compete with the same miRNA suggesting a higher expression of genes in the COPD-specific ceRNA network. Hsa-miR-21-3p is the largest connected point in the network, but the proportion of genes upregulated by hsa-miR-21-3p is low (P = 0.1406). This indicates that the regulatory relationship of competitive inhibition has little effect on has-miR-21, and the high expression pattern is a poor prognostic factor in COPD. Hsa-miR-15a-5p is the most significant miRNA with the highest proportion of DEGs. And ANXA2P3 is the only gene in the COPD ceRNA network that interferes with hsa-miR-15a-5p. In addition, we found that has-miR-1184- and has-miR-99-cored modules were significant, and genes ZDHHC18, PCGF3, and KIAA0319L interacting with them were all associated with COPD prognosis, and high expression of these genes could lead to poor prognosis in COPD.The key regulators such as miR-21, miR-15a, ANXA2P3, ZDHHC18, PCGF3, and KIAA0319L can be used as prognostic biomarkers for early intervention in COPD with SARS-CoV-2 infection.

Exosomal miR-17-5p derived from epithelial cells is involved in aberrant epithelium-fibroblast crosstalk and induces the development of oral submucosal fibrosis

Oral submucous fibrosis (OSF) is a chronic and inflammatory mucosal disease caused by betel quid chewing, which belongs to oral potentially malignant disorders. Abnormal fibroblast differentiation leading to disordered collagen metabolism is the core process underlying OSF development. The epithelium, which is the first line of defense against the external environment, can convert external signals into pathological signals and participate in the remodeling of the fibrotic microenvironment. However, the specific mechanisms by which the epithelium drives fibroblast differentiation remain unclear. In this study, we found that Arecoline-exposed epithelium communicated with the fibrotic microenvironment by secreting exosomes. MiR-17-5p was encapsulated in epithelial cell-derived exosomes and absorbed by fibroblasts, where it promoted cell secretion, contraction, migration and fibrogenic marker (α-SMA and collagen type I) expression. The underlying molecular mechanism involved miR-17-5p targeting Smad7 and suppressing the degradation of TGF-β receptor 1 (TGFBR1) through the E3 ubiquitination ligase WWP1, thus facilitating downstream TGF-β pathway signaling. Treatment of fibroblasts with an inhibitor of miR-17-5p reversed the contraction and migration phenotypes induced by epithelial-derived exosomes. Exosomal miR-17-5p was confirmed to function as a key regulator of the phenotypic transformation of fibroblasts. In conclusion, we demonstrated that Arecoline triggers aberrant epithelium-fibroblast crosstalk and identified that epithelial cell-derived miR-17-5p mediates fibroblast differentiation through the classical TGF-β fibrotic pathway, which provided a new perspective and strategy for the diagnosis and treatment of OSF.

Environmental pollutants exposure-derived extracellular vesicles: crucial players in respiratory disorders

BACKGROUND

Individual exposure to environmental pollutants, as one of the most influential drivers of respiratory disorders, has received considerable attention due to its preventability and controllability. Considering that the extracellular vesicle (EV) was an emerging intercellular communication medium, recent studies have highlighted the crucial role of environmental pollutants derived EVs (EPE-EVs) in respiratory disorders.

METHODS

PubMed and Web of Science were searched from January 2018 to December 2023 for publications with key words of environmental pollutants, respiratory disorders and EVs.

RESULTS

Environmental pollutants could disrupt airway intercellular communication by indirectly stimulating airway barrier cells to secrete endogenous EVs, or directly transmitting exogenous EVs, mainly by biological pollutants. Mechanistically, EPE-EVs transferred specific contents to modulate biological functions of recipient cells, to induce respiratory inflammation and impair tissue and immune function, which consequently contributed to the development of respiratory diseases, such as asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, pulmonary hypertension, lung cancer and infectious lung diseases. Clinically, EVs could emerged as promising biomarkers and biological agents for respiratory diseases attributed by their specificity, convenience, sensibility and stability.

CONCLUSIONS

Further studies of EPE-EVs are helpful to understand the aetiology and pathology of respiratory diseases, and facilitate the precision respiratory medicine in risk screening, early diagnosis, clinical management and biotherapy.

Epithelium-derived exosomes promote silica nanoparticles-induced pulmonary fibroblast activation and collagen deposition via modulating fibrotic signaling pathways and their epigenetic regulations

BACKGROUND

In the context of increasing exposure to silica nanoparticles (SiNPs) and ensuing respiratory health risks, emerging evidence has suggested that SiNPs can cause a series of pathological lung injuries, including fibrotic lesions. However, the underlying mediators in the lung fibrogenesis caused by SiNPs have not yet been elucidated.

RESULTS

The in vivo investigation verified that long-term inhalation exposure to SiNPs induced fibroblast activation and collagen deposition in the rat lungs. In vitro, the uptake of exosomes derived from SiNPs-stimulated lung epithelial cells (BEAS-2B) by fibroblasts (MRC-5) enhanced its proliferation, adhesion, and activation. In particular, the mechanistic investigation revealed SiNPs stimulated an increase of epithelium-secreted exosomal miR-494-3p and thereby disrupted the TGF-β/BMPR2/Smad pathway in fibroblasts via targeting bone morphogenetic protein receptor 2 (BMPR2), ultimately resulting in fibroblast activation and collagen deposition. Conversely, the inhibitor of exosomes, GW4869, can abolish the induction of upregulated miR-494-3p and fibroblast activation in MRC-5 cells by the SiNPs-treated supernatants of BEAS-2B. Besides, inhibiting miR-494-3p or overexpression of BMPR2 could ameliorate fibroblast activation by interfering with the TGF-β/BMPR2/Smad pathway.

CONCLUSIONS

Our data suggested pulmonary epithelium-derived exosomes serve an essential role in fibroblast activation and collagen deposition in the lungs upon SiNPs stimuli, in particular, attributing to exosomal miR-494-3p targeting BMPR2 to modulate TGF-β/BMPR2/Smad pathway. Hence, strategies targeting exosomes could be a new avenue in developing therapeutics against lung injury elicited by SiNPs.

Protective effect of Xixin-Ganjiang herb pair for warming the lungs to dissolve phlegm in chronic obstructive pulmonary disease rats based on integrated network pharmacology and metabolomics

Xixin-Ganjiang herb pair (XGHP) is a classic combination for warming the lungs to dissolve phlegm and is often used to treat a variety of chronic lung diseases; it can treat the syndrome of cold phlegm obstruction of lungs. First, ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to examine the composition of XGHP, and network pharmacology was used to predict its potential core targets and signaling pathways in the current study. Second, a rat model of chronic obstructive pulmonary disease (COPD) was established for assessing the anti-COPD activity of XGHP, and metabolomics was used to explore the biomarkers and metabolic pathways. Finally, the sample was validated using molecular docking and Western blotting. The integration of metabolomics and network pharmacology results identified 11 targets, 3 biomarkers, 3 pathways, and 2 metabolic pathways. Western blotting showed that XGHP effectively regulated the expression of core proteins via multiple signaling pathways (downregulation of toll-like receptor 4 [TLR4] and upregulation of serine/threonine-protein kinase 1 [p-AKT1] and nitric oxide synthase 3 [NOS3]). Molecular docking results showed that the 10 potentially active components of XGHP have good affinity with tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), matrix metalloproteinase 9 (MMP-9), TLR4, p-AKT1, and NOS3. Our findings suggest that XGHP may regulate glucolipid metabolism, improve energy supply, and inhibit inflammatory responses (TNF-α, IL-6, and MMP-9) via the PI3K-Akt signaling pathway and HIF-1 signaling pathway in the management of COPD.

MCF-7 cell - derived exosomes were involved in protecting source cells from the damage caused by tributyltin chloride via transport function

Tributyltin chloride (TBTC) is a ubiquitous environmental pollutant with various adverse effects on human health. Exosomes are cell - derived signaling and substance transport vesicles. This investigation aimed to explore whether exosomes could impact the toxic effects caused by TBTC via their transport function. Cytotoxicity, DNA and chromosome damage caused by TBTC on MCF-7 cells were analyzed with CCK-8, flow cytometry, comet assay and micronucleus tests, respectively. Exosomal characterization and quantitative analysis were performed with ultracentrifugation, transmission electron microscope (TEM) and bicinchoninic acid (BCA) methods. TBTC content in exosomes was detected with Liquid Chromatography-Mass Spectrometry (LC-MS). The impacts of exosomal secretion on the toxic effects of TBTC were analyzed. Our data indicated that TBTC caused significant cytotoxicity, DNA and chromosome damage effects on MCF-7 cells, and a significantly increased exosomal secretion. Importantly, TBTC could be transported out of MCF-7 cells by exosomes. Further, when exosomal secretion was blocked with GW4869, the toxic effects of TBTC were significantly exacerbated. We concluded that TBTC promoted exosomal secretion, which in turn transported TBTC out of the source cells to alleviate its toxic effects. This investigation provided a novel insight into the role and mechanism of exosomal release under TBTC stress.

Exosome-encapsulated lncRNA HOTAIRM1 contributes to PM2.5-aggravated COPD airway remodeling by enhancing myofibroblast differentiation

Emphysema, myofibroblast accumulation and airway remodeling can occur in the lungs due to exposure to atmospheric pollution, especially fine particulate matter (PM2.5), leading to chronic obstructive pulmonary disease (COPD). Specifically, bronchial epithelium-fibroblast communication participates in airway remodeling, which results in COPD. An increasing number of studies are now being conducted on the role of exosome-mediated cell-cell communication in disease pathogenesis. Here, we investigated whether exosomes generated from bronchial epithelial cells could deliver information to normal stromal fibroblasts and provoke cellular responses, resulting in airway obstruction in COPD. We studied the mechanism of exosome-mediated intercellular communication between human bronchial epithelial (HBE) cells and primary lung fibroblasts (pLFs). We found that PM2.5-induced HBE-derived exosomes promoted myofibroblast differentiation in pLFs. Then, the exosomal lncRNA expression profiles derived from PM2.5-treated HBE cells and nontreated HBE cells were investigated using an Agilent Human LncRNA Array. Combining coculture assays and direct exosome treatment, we found that HBE cell-derived exosomal HOTAIRM1 facilitated the myofibroblast differentiation of pLFs. Surprisingly, we discovered that exosomal HOTAIRM1 enhanced pLF proliferation to secrete excessive collagen secretion, leading to airway obstruction by stimulating the TGF-β/SMAD3 signaling pathway. Significantly, PM2.5 reduced FEV1/FVC and FEV1 and increased the level of serum exosomal HOTAIRM1 in healthy people; moreover, serum exosomal HOTAIRM1 was associated with PM2.5-related reductions in FEV1/FVC and FVC. These findings show that PM2.5 triggers alterations in exosome components and clarify that one of the paracrine mediators of myofibroblast differentiation is bronchial epithelial cell-derived HOTAIRM1, which has the potential to be an effective prevention and therapeutic target for PM2.5-induced COPD.

The novel insights of epithelial-derived exosomes in various fibrotic diseases

The characteristics of fibrosis include the abnormal accumulation of extracellular matrix proteins and abnormal tissue repair caused by injury, infection, and inflammation, leading to a significant increase in organ failure and mortality. Effective and precise treatments are urgently needed to halt and reverse the progression of fibrotic diseases. Exosomes are tiny vesicles derived from endosomes, spanning from 40 to 160 nanometers in diameter, which are expelled into the extracellular matrix environment by various cell types. They play a crucial role in facilitating cell-to-cell communication by transporting a variety of cargoes, including proteins, RNA, and DNA. Epithelial cells serve as the primary barrier against diverse external stimuli that precipitate fibrotic diseases. Numerous research suggests that exosomes from epithelial cells have a significant impact on several fibrotic diseases. An in-depth comprehension of the cellular and molecular mechanisms of epithelial cell-derived exosomes in fibrosis holds promise for advancing the exploration of novel diagnostic biomarkers and clinical drug targets. In this review, we expand upon the pathogenic mechanisms of epithelium-derived exosomes and highlight their role in the fibrotic process by inducing inflammation and activating fibroblasts. In addition, we are particularly interested in the bioactive molecules carried by epithelial-derived exosomes and their potential value in the diagnosis and treatment of fibrosis and delineate the clinical utility of exosomes as an emerging therapeutic modality, highlighting their potential application in addressing various medical conditions.

A new frontier in precision medicine: Exploring the role of extracellular vesicles in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory airway disease characterized by progressive respiratory difficulties. It has a high incidence and disability rate worldwide. However, currently there is still a lack of highly effective treatment methods for COPD, only symptom relief is possible. Therefore, there is an urgent need to explore new treatment options. Almost all cells can secrete extracellular vesicles (EVs), which participate in many physiological activities by transporting cargoes and are associated with the pathogenesis of various diseases. Recently, many scholars have extensively studied the relationship between COPD and EVs, which has strongly demonstrated the significant impact of EVs from different sources on the occurrence and development of COPD. Therefore, EVs are a good starting point and new opportunity for the diagnosis and treatment of COPD. In this review, we mainly describe the current mechanisms of EVs in the pathogenesis of COPD, also the relationship between diagnosis, prognosis, and treatment. At the same time, we also introduce some new methods for COPD therapy based on EVs. It is hoped that this article can provide new ideas for future research and contribute to the development of precision medicine.

Tumor-associated macrophage-derived exosomal miR21-5p promotes tumor angiogenesis by regulating YAP1/HIF-1α axis in head and neck squamous cell carcinoma

Extracellular vesicles (EVs) have recently received increasing attention as essential mediators of communication between tumor cells and their microenvironments. Tumor-associated macrophages (TAMs) play a proangiogenic role in various tumors, especially head and neck squamous cell carcinoma (HNSCC), and angiogenesis is closely related to tumor growth and metastasis. This research focused on exploring the mechanisms by which EVs derived from TAMs modulate tumor angiogenesis in HNSCC. Our results indicated that TAMs infiltration correlated positively with microvascular density in HNSCC. Then we collected and identified EVs from TAMs. In the microfluidic chip, TAMs derived EVs significantly enhanced the angiogenic potential of pHUVECs and successfully induced the formation of perfusable blood vessels. qPCR and immunofluorescence analyses revealed that EVs from TAMs transferred miR-21-5p to endothelial cells (ECs). And targeting miR-21-5p of TAMs could effectively inhibit TAM-EVs induced angiogenesis. Western blot and tube formation assays showed that miR-21-5p from TAM-EVs downregulated LATS1 and VHL levels but upregulated YAP1 and HIF-1α levels, and the inhibitors of YAP1 and HIF-1α could both reduce the miR-21-5p enhanced angiogenesis in HUVECs. The in vivo experiments further proved that miR-21-5p carried by TAM-EVs promoted the process of tumor angiogenesis via YAP1/HIF-1α axis in HNSCC. Conclusively, TAM-derived EVs transferred miR-21-5p to ECs to target the mRNA of LATS1 and VHL, which inhibited YAP1 phosphorylation and subsequently enhanced YAP1-mediated HIF-1α transcription and reduced VHL-mediated HIF-1α ubiquitination, contributing to angiogenesis in HNSCC. These findings present a novel regulatory mechanism of tumor angiogenesis, and miR-21-5p/YAP1/HIF-1α might be a potential therapeutic target for HNSCC.

MiR-23a-5p alleviates chronic obstructive pulmonary disease through targeted regulation of RAGE-ROS pathway

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease and represents the third leading cause of death worldwide. This study aimed to investigate miRNA regulation of Receptor for Advanced Glycation End-products (RAGE), a causal receptor in the pathogenesis of cigarette smoke (CS)-related COPD, to guide development of therapeutic strategies.

METHODS

RAGE expression was quantified in lung tissue of COPD patients and healthy controls, and in mice with CS-induced COPD. RNA-sequencing of peripheral blood from COPD patients with binding site prediction was used to screen differentially expressed miRNAs that may interact with RAGE. Investigation of miR-23a-5p as a potential regulator of COPD progression was conducted with miR-23a-5p agomir in COPD mice in vivo using histology and SCIREQ functional assays, while miR-23a-5p mimics or RAGE inhibitor were applied in 16-HBE human bronchial epithelial cells in vitro. RNA-sequencing, ELISA, and standard molecular techniques were used to characterize downstream signaling pathways in COPD mice and 16-HBE cells treated with cigarette smoke extract (CSE).

RESULTS

RAGE expression is significantly increased in lung tissue of COPD patients, COPD model mice, and CSE-treated 16-HBE cells, while inhibiting RAGE expression significantly reduces COPD severity in mice. RNA-seq analysis of peripheral blood from COPD patients identified miR-23a-5p as the most significant candidate miRNA interaction partner of RAGE, and miR-23a-5p is significantly downregulated in mice and cells treated with CS or CSE, respectively. Injection of miR-23a-5p agomir leads to significantly reduced airway inflammation and alleviation of symptoms in COPD mice, while overexpressing miR-23a-5p leads to improved lung function. RNA-seq with validation confirmed that reactive oxygen species (ROS) signaling is increased under CSE-induced aberrant upregulation of RAGE, and suppressed in CSE-stimulated cells treated with miR-23a-5p mimics or overexpression. ERK phosphorylation and subsequent cytokine production was also increased under RAGE activation, but inhibited by increasing miR-23a-5p levels, implying that the miR-23a-5p/RAGE/ROS axis mediates COPD pathogenesis via ERK activation.

CONCLUSIONS

This study identifies a miR-23a-5p/RAGE/ROS signaling axis required for pathogenesis of COPD. MiR-23a-5p functions as a negative regulator of RAGE and downstream activation of ROS signaling, and can inhibit COPD progression in vitro and in vivo, suggesting therapeutic targets to improve COPD treatment.

The role of extracellular vesicles in COPD and potential clinical value

Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung disease and a major health burden worldwide. Extracellular vesicles (EVs) are nanosized vesicles which possess a lipid bilayer structure that are secreted by various cells. They contain a variety of bioactive substances, which can regulate various physiological and pathological processes and are closely related to the development of diseases. Recently, EVs have emerged as a novel tool for intercellular crosstalk, which plays an essential role in COPD development. This paper reviews the role of EVs in the development of COPD and their potential clinical value, in order to provide a reference for further research on COPD.

DNMT3a-mediated upregulation of the stress inducible protein sestrin-2 contributes to malignant transformation of human bronchial epithelial cells following nickel exposure

BACKGROUND

Nickel is a confirmed human lung carcinogen. Nonetheless, the molecular mechanisms driving its carcinogenic impact on lung tissue remain poorly defined. In this study, we assessed SESN2 expression and the signaling pathways responsible for cellular transformation in human bronchial epithelial cells (HBECs) as a result of nickel exposure.

METHODS

We employed the Western blotting to determine the induction of SESN2 by nickel. To clarify the signaling pathways leading to cellular transformation following nickel exposure, we applied techniques such as gene knockdown, methylation-specific PCR, and chromatin immunoprecipitation.

RESULT

Exposure to nickel results in the upregulation of SESN2 and the initiation of autophagy in human bronchial epithelial cells (HBECs). This leads to degradation of HUR protein and consequently downregulation of USP28 mRNA, PP2AC protein, β-catenin protein, and diminished VHL transcription, culminating in the accumulation of hypoxia-inducible factor-1α (HIF-1α) and the malignant transformation of these cells. Mechanistic studies revealed that the increased expression of SESN2 is attributed to the demethylation of the SESN2 promoter induced by nickel, a process facilitated by decreased DNA methyl-transferase 3 A (DNMT3a) expression, while The downregulation of VHL transcription is linked to the suppression of the PP2A-C/GSK3β/β-Catenin/C-Myc pathway. Additionally, we discovered that SESN2-mediated autophagy triggers the degradation of HUR protein, which subsequently reduces the stability of USP28 mRNA and inhibits the PP2A-C/GSK3β/β-Catenin pathway and c-Myc transcription in HBECs post nickel exposure.

CONCLUSION

Our results reveal that nickel exposure leads to the downregulation of DNMT3a, resulting in the hypomethylation of the SESN2 promoter and its protein induction. This triggers autophagy-dependent suppression of the HUR/USP28/PP2A/β-Catenin/c-Myc pathway, subsequently leading to reduced VHL transcription, accumulation of HIF-1α protein, and the malignant transformation of human bronchial epithelial cells (HBECs). Our research offers novel insights into the molecular mechanisms that underlie the lung carcinogenic effects of nickel exposure. Specifically, nickel induces aberrant DNA methylation in the SESN2 promoter region through the decrease of DNMT3a levels, which ultimately leads to HIF-1α protein accumulation and the malignant transformation of HBECs. Specifically, nickel initiates DNA-methylation of the SESN2 promoter region by decreasing DNMT3a, ultimately resulting in HIF-1α protein accumulation and malignant transformation of HBECs. This study highlights DNMT3a as a potential prognostic biomarker or therapeutic target to improve clinical outcomes in lung cancer patients.

Crosstalk between proximal tubular epithelial cells and other interstitial cells in tubulointerstitial fibrosis after renal injury

The energy needs of tubular epithelial components, especially proximal tubular epithelial cells (PTECs), are high and they heavily depend on aerobic metabolism. As a result, they are particularly vulnerable to various injuries caused by factors such as ischemia, proteinuria, toxins, and elevated glucose levels. Initial metabolic and phenotypic changes in PTECs after injury are likely an attempt at survival and repair. Nevertheless, in cases of recurrent or prolonged injury, PTECs have the potential to undergo a transition to a secretory state, leading to the generation and discharge of diverse bioactive substances, including transforming growth factor-β, Wnt ligands, hepatocyte growth factor, interleukin (IL)-1β, lactic acid, exosomes, and extracellular vesicles. By promoting fibroblast activation, macrophage recruitment, and endothelial cell loss, these bioactive compounds stimulate communication between epithelial cells and other interstitial cells, ultimately worsening renal damage. This review provides a summary of the latest findings on bioactive compounds that facilitate the communication between these cellular categories, ultimately leading to the advancement of tubulointerstitial fibrosis (TIF).

Expression and regulation of HIF-1a in hypoxic pulmonary hypertension: Focus on pathological mechanism and Pharmacological Treatment

Hypoxia inducible factor-1(HIF-1), a heterodimeric transcription factor, is composed of two subunits (HIF-1α and HIF-1β). It is considered as an important transcription factor for regulating oxygen changes in hypoxic environment, which can regulate the expression of various hypoxia-related target genes and play a role in acute and chronic hypoxia pulmonary vascular reactions. In this paper, the function and mechanism of HIF-1a expression and regulation in hypoxic pulmonary hypertension (HPH) were reviewed, and current candidate schemes for treating pulmonary hypertension by using HIF-1a as the target were introduced, so as to provide reference for studying the pathogenesis of HPH and screening effective treatment methods.

Astragaloside IV (ASIV) Mediates Endothelial Progenitor Cell (EPC) Exosomal LINC01963 to Inhibit Pyroptosis and Oxidative Stress in High Glucose-impaired Endothelial Cells

BACKGROUND

Hyperglycemia is widespread in the world's population, increasing the risk of many diseases. This study aimed to explore the regulatory effect and mechanism of astragaloside IV (ASIV)-mediated endothelial progenitor cells (EPCs) exosomal LINC01963 in endothelial cells (HUVECs) impaired by high glucose.

METHODS

Morphologies of exosomes were observed by light microscope and electron microscope. Immunofluorescence was used to identify EPCs and detect the expressions of caspase-1. LINC01963 was detected by quantitative reverse transcription PCR. NLRP3, ASC, and caspase-3 were detected by Western Blot. Nanoparticle tracking analysis was carried out to analyze the exosome diameter. High-throughput sequencing was applied to screen target lncRNAs. The proliferation of endothelial cells was measured by cell counting kit-8 assay. The apoptosis level of HUVECs was detected by flow cytometry and TdT-mediated dUTP Nick-End labeling. The levels of IL- 1β, IL-18, ROS, SOD, MDA, and LDH were measured by enzyme-linked immunosorbent assay.

RESULTS

ASIV could promote the secretion of the EPC exosome. LINC01963 was obtained by high-throughput sequencing. It was observed that high glucose could inhibit the proliferation, reduce the level of SOD, the expression of NLRP3, ASC, and caspase- 1, increase the levels of IL-1β, IL-18, ROS, MDA, and LDH, and promote apoptosis of HUVECs. Whereas LINC01963 could inhibit the apoptosis of HUVECs, the increase the expression of NLRP3, ASC, and caspase-1, and decrease the levels of IL-1β, IL-18, ROS, MDA, and LDH.

CONCLUSION

EPCs exosomal LINC01963 play an inhibitory role in high glucoseinduced pyroptosis and oxidative stress of HUVECs. This study provides new ideas and directions for treating hyperglycemia and researching exosomal lncRNAs.

Characterizing the extracellular vesicle proteomic landscape of the human airway using in vitro organotypic multi-cellular models

Extracellular vesicle (EV)-mediated intercellular communication significantly influences pulmonary cell health and disease, yet in vitro methods to investigate these mechanisms are limited. We hypothesize that organotypic models of the airway can be leveraged to investigate EV-mediated intercellular signaling, focusing on EV proteomic content as a case study. Two in vitro airway culture models were evaluated by mass spectrometry-based proteomics analysis: a tri-culture model consisting of alveolar epithelial, fibroblast, and lung microvascular endothelial cells and a co-culture model of alveolar epithelial and fibroblasts. EVs isolated from the tri-culture model were enriched with EV proteins regulating RNA-to-protein translation. EVs isolated from the co-culture model were enriched with EV biogenesis and extracellular matrix signaling proteins. These model-specific differences suggest that different pulmonary cell types uniquely affect EV composition and the biological pathways influenced by the EV proteome in recipient cells. These findings can inform future studies surrounding EV-related pulmonary disease pathogenesis and therapeutics.

Protease-armed, Pathogenic Extracellular Vesicles Link Smoking and Chronic Obstructive Pulmonary Disease

Rationale: Mounting evidence demonstrates a role for extracellular vesicles (EVs) in driving lung disorders, such as chronic obstructive pulmonary disease (COPD). Although cigarette smoke (CS) is the primary risk factor for COPD, a link between CS and the EVs that could lead to COPD is unknown. Objective: To ascertain whether exposure to CS elicits a proteolytic EV signature capable of driving disease pathogenesis. Methods: Protease expression and enzymatic activity were measured in EVs harvested from the BAL fluid of smoke-exposed mice and otherwise healthy human smokers. Pathogenicity of EVs was examined using pathological tissue scoring after EV transfer into naive recipient mice. Measurements and Main Results: The analyses revealed a unique EV profile defined by neutrophil- and macrophage-derived EVs. These EVs are characterized by abundant surface expression of neutrophil elastase (NE) and matrix metalloproteinase 12 (MMP12), respectively. CS-induced mouse or human-derived airway EVs had a robust capacity to elicit rapid lung damage in naive recipient mice, with an additive effect of NE- and MMP12-expressing EVs. Conclusions: These studies demonstrate the capacity of CS to drive the generation of unique EV populations containing NE and MMP12. The coordinated action of these EVs is completely sufficient to drive emphysematous disease, and their presence could operate as a prognostic indicator for COPD development. Furthermore, given the robust capacity of these EVs to elicit emphysema in naive mice, they provide a novel model to facilitate preclinical COPD research. Indeed, the development of this model has led to the discovery of a previously unrecognized CS-induced protective mechanism against EV-mediated damage.

Effect of environmental exposures on cancer risk: Emerging role of non-coding RNA shuttled by extracellular vesicles

Environmental and lifestyle exposures have a huge impact on cancer risk; nevertheless, the biological mechanisms underlying this association remain poorly understood. Extracellular vesicles (EVs) are membrane-enclosed particles actively released by all living cells, which play a key role in intercellular communication. EVs transport a variegate cargo of biomolecules, including non-coding RNA (ncRNA), which are well-known regulators of gene expression. Once delivered to recipient cells, EV-borne ncRNAs modulate a plethora of cancer-related biological processes, including cell proliferation, differentiation, and motility. In addition, the ncRNA content of EVs can be altered in response to outer stimuli. Such changes can occur either as an active attempt to adapt to the changing environment or as an uncontrolled consequence of cell homeostasis loss. In either case, such environmentally-driven alterations in EV ncRNA might affect the complex crosstalk between malignant cells and the tumor microenvironment, thus modulating the risk of cancer initiation and progression. In this review, we summarize the current knowledge about EV ncRNAs at the interface between environmental and lifestyle determinants and cancer. In particular, we focus on the effect of smoking, air and water pollution, diet, exercise, and electromagnetic radiation. In addition, we have conducted a bioinformatic analysis to investigate the biological functions of the genes targeted by environmentally-regulated EV microRNAs. Overall, we draw a comprehensive picture of the role of EV ncRNA at the interface between external factors and cancer, which could be of great interest to the development of novel strategies for cancer prevention, diagnosis, and therapy.

Pacenta polypeptide injection alleviates the fibrosis and inflammation in cigarette smoke extracts-induced BEAS-2B cells by modulating MMP-9/TIMP-1 signaling

Chronic obstructive pulmonary disease (COPD) has high morbidity and mortality. Here, we aimed to explore the roles and potential correlation of placenta polypeptide injection (PPI) and MMP-9/TIMP-1 signaling pathway in COPD. BEAS-2B cells were treated with cigarette smoke extract (CSE) to establish a COPD cell model in vitro. The cell survival and cytotoxic effect were measured by CCK-8, LDH release and flow cytometry assays. The inflammatory responses were determined by western blot and ELISA assay. Cell fibrosis was assessed by immunofluorescence and western blot assays. PPI treatment had no cytotoxic effect on BEAS-2B cells until the final concentration reached to 10%. In the range of 0%-8% final concentration, PPI treatment weakened CSE-induced the decrease of cell viability and the increase of LDH level in a concentration-dependent manner. Four percent PPI treatment enhanced cell viability and decreased cell apoptosis of CSE-treated cells in a time-dependent manner. Moreover, 4% PPI treatment significantly decreased inflammatory responses and fibrosis induced by CSE, while AMPA (MMPs agonist) had opposite effects. Notably, AMPA reversed the protective roles of PPI on CSE-induced inflammation and fibrosis. Mechanistically, 4% PPI treatment significantly suppressed MMP-1, MMP-2, MMP-3, MMP-9, MMP-13, and MMP-19 levels, but enhanced TIMP-1, TIMP-2, TIMP-3, and TIMP-4 levels. Among them, MMP-9 and TIMP-1 might be the main target of PPI. PPI effectively attenuated CSE-induced inflammation and fibrosis in vitro by regulating MMP-9/TIMP-1 signaling pathway.

Extracellular vesicles-transmitted long non-coding RNA MTUS2-5 promotes proliferation and vascularization of human vascular endothelial cells in patients with Budd-Chiari syndrome

The high rates of misdiagnosis and untreated mortality with regard to Budd-Chiari syndrome (BCS) indicated the need to screen effective biomarkers. The aim of this study was to explore the function of extracellular vesicles (EVs) in patients with BCS as well as associated mechanisms. First, differentially expressed long non-coding RNAs (lncRNAs) from EVs separated from serum between BCS and healthy controls were screened using microarray analysis. Second, the proliferation, migration and tube formation of human vascular endothelial cells (HUVECs) were detected after EVs treatment, along with vascular endothelial growth factor (VEGF) levels and inflammatory factors from the cell supernatant. Last, the overexpressed lncRNA was transfected into the cells to further explore the mechanisms involved. Extracellular vesicles of BCS patients have significantly higher levels of lncRNA MTUS2-5 than healthy controls. Apparently, treatment with EVs from BCS or the ones transfected with plasmids that overexpress lncRNA MTUS2-5 enhances proliferation, migration and angiogenesis capacity. The results were considerably better than those obtained from treatment with EVs from healthy controls or transfection with the normal control plasmid, which also elevated the level of VEGF and inflammatory factors. Furthermore, FOS and PTGS2 were potentially regulated by the lncRNA MTUS2-5 transmitted by EVs. The lncRNA MTUS2-5 in EVs plays an important role in angiogenesis in the Budd-Chiari syndrome.

Exosomal microRNA/miRNA Dysregulation in Respiratory Diseases: From Mycoplasma-Induced Respiratory Disease to COVID-19 and Beyond

Respiratory diseases represent a significant economic and health burden worldwide, affecting millions of individuals each year in both human and animal populations. MicroRNAs (miRNAs) play crucial roles in gene expression regulation and are involved in various physiological and pathological processes. Exosomal miRNAs and cellular miRNAs have been identified as key regulators of several immune respiratory diseases, such as chronic respiratory diseases (CRD) caused by Mycoplasma gallisepticum (MG), Mycoplasma pneumoniae pneumonia (MMP) caused by the bacterium Mycoplasma pneumoniae, coronavirus disease 2019 (COVID-19), chronic obstructive pulmonary disease (COPD), asthma, and acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Consequently, miRNAs seem to have the potential to serve as diagnostic biomarkers and therapeutic targets in respiratory diseases. In this review, we summarize the current understanding of the functional roles of miRNAs in the above several respiratory diseases and discuss the potential use of miRNAs as stable diagnostic biomarkers and therapeutic targets for several immune respiratory diseases, focusing on the identification of differentially expressed miRNAs and their targeting of various signaling pathways implicated in disease pathogenesis. Despite the progress made, unanswered questions and future research directions are discussed to facilitate personalized and targeted therapies for patients with these debilitating conditions.

Long Noncoding RNA ZBED5-AS1 Facilitates Tumor Progression and Metastasis in Lung Adenocarcinoma via ZNF146/ATR/Chk1 Axis

Long noncoding RNAs (lncRNAs) have been implicated in tumorigenesis, including lung adenocarcinoma (LUAD). However, the functional and regulatory mechanisms of lncRNAs in LUAD remain poorly understood. In this study, we investigated the role of lncRNA ZBED5-AS1 in LUAD. We found that ZBED5-AS1 was upregulated in LUAD specimens and overexpressed in LUAD cell lines. ZBED5-AS1 promoted LUAD cell proliferation, migration, and invasion in vitro and promoted LUAD cell growth in vivo. ZBED5-AS1 promoted ZNF146 expression, activating the ATR/Chk1 pathway and leading to LUAD progression. We observed that exosomes from LUAD cells have a higher expression of ZBED5-AS1 compared with exosomes from the normal cell line BEAS-2B. Coculture experiments with exosomes showed that ZBED5-AS1 expression was downregulated after coculture with Si-ZBED5-AS1 exosomes, and coculture with exosomes with low ZBED5-AS1 expression inhibited proliferation and invasion of LUAD cells. Our results indicate that ZBED5-AS1 functions as an oncogenic factor in LUAD cells by targeting the ZNF146/ATR/Chk1 axis.

Overexpression of hypoxia-inducible factor-1α in hidradenitis suppurativa: the link between deviated immunity and metabolism

Hypoxia-inducible factor-1α (HIF-1α) is the master transcription factor of glycolysis, Th17 cell differentiation and suppression of regulatory T cells. In the skin and serum of patients with psoriasis vulgaris, increased expression of HIF-1α has been reported, whereas HIF-1α expression in the skin and serum of patients with hidradenitis suppurativa (HS) has not yet been studied. The objective of the study is to demonstrate is there a role for HIF-1α in the pathogenesis of hidradenitis suppurativa, and its relation to HS severity. Twenty patients suffering from hidradenitis suppurativa were included in the study. Punch biopsies were taken from lesional skin for the determination of HIF-1α expression by immunohistochemical staining, and HIF-1α gene expression by quantitative reverse transcription real time PCR. Quantification of HIF-1α protein concentration was done by enzyme-linked immunosorbent assay. Twenty socio-demographically cross-matched healthy volunteers served as controls. We found increased serum levels of HIF-1α. Literature-derived evidence indicates that the major clinical triggering factors of HS, obesity, and smoking are associated with hypoxia and enhanced HIF-1α expression. Pro-inflammatory cytokines such as tumor necrosis factor-[Formula: see text] via upregulation of nuclear factor [Formula: see text]B enhance HIF-1α expression. HIF-1α plays an important role for keratinocyte proliferation, especially for keratinocytes of the anagen hair follicle, which requires abundant glycolysis providing sufficient precursors molecules for biosynthetic pathways. Metformin via inhibition of mTORC1 as well as adalimumab attenuate HIF-1α expression, the key mediator between Th17-driven deviated immunity and keratinocyte hyperproliferation. In accordance with psoriasis, our study identifies HS as an HIF-1α-driven inflammatory skin disease and offers a new rationale for the prevention and treatment of HS by targeting HIF-1[Formula: see text] overexpression.

The Role of miRNA in Renal Fibrosis Leading to Chronic Kidney Disease

Chronic kidney disease (CKD) is an important health concern that is expected to be the fifth most widespread cause of death worldwide by 2040. The presence of chronic inflammation, oxidative stress, ischemia, etc., stimulates the development and progression of CKD. Tubulointerstitial fibrosis is a common pathomechanism of renal dysfunction, irrespective of the primary origin of renal injury. With time, fibrosis leads to end-stage renal disease (ESRD). Many studies have demonstrated that microRNAs (miRNAs, miRs) are involved in the onset and development of fibrosis and CKD. miRNAs are vital regulators of some pathophysiological processes; therefore, their utility as therapeutic agents in various diseases has been suggested. Several miRNAs were demonstrated to participate in the development and progression of kidney disease. Since renal fibrosis is an important problem in chronic kidney disease, many scientists have focused on the determination of miRNAs associated with kidney fibrosis. In this review, we present the role of several miRNAs in renal fibrosis and the potential pathways involved. However, as well as those mentioned above, other miRs have also been suggested to play a role in this process in CKD. The reports concerning the impact of some miRNAs on fibrosis are conflicting, probably because the expression and regulation of miRNAs occur in a tissue- and even cell-dependent manner. Moreover, different assessment modes and populations have been used. There is a need for large studies and clinical trials to confirm the role of miRs in a clinical setting. miRNAs have great potential; thus, their analysis may improve diagnostic and therapeutic strategies.

Regulatory roles of Osteopontin in lung epithelial inflammation and epithelial-telocyte interaction

BACKGROUND

Lung epithelial cells play important roles in lung inflammation and injury, although mechanisms remain unclear. Osteopontin (OPN) has essential roles in epithelial damage and repair and in lung cancer biological behaviours. Telocyte (TC) is a type of interstitial cell that interacts with epithelial cells to alleviate acute inflammation and lung injury. The present studies aim at exploring potential mechanisms by which OPN regulates the epithelial origin lung inflammation and the interaction of epithelial cells with TCs in acute and chronic lung injury.

METHODS

The lung disease specificity of OPN and epithelial inflammation were defined by bioinformatics. We evaluated the regulatory roles of OPN in OPN-knockdown or over-expressed bronchial epithelia (HBEs) challenged with cigarette smoke extracts (CSE) or in animals with genome OPN knockout (gKO) or lung conditional OPN knockout (cKO). Acute lung injury and chronic obstructive pulmonary disease (COPD) were induced by smoking or lipopolysaccharide (LPS). Effects of OPN on PI3K subunits and ERK were assessed using the inhibitors. Spatialization and distribution of OPN, OPN-positive epithelial subtypes, and TCs were defined by spatial transcriptomics. The interaction between HBEs and TCs was assayed by the co-culture system.

RESULTS

Levels of OPN expression increased in smokers, smokers with COPD, and smokers with COPD and lung cancer, as compared with healthy nonsmokers. LPS and/or CSE induced over-production of cytokines from HBEs, dependent upon the dysfunction of OPN. The severity of lung inflammation and injury was significantly lower in OPN-gKO or OPN-cKO mice. HBEs transferred with OPN enhanced the expression of phosphoinositide 3-kinase (PI3K)CA/p110α, PIK3CB/p110β, PIK3CD/p110δ, PIK3CG/p110γ, PIK3R1, PIK3R2 or PIK3R3. Spatial locations of OPN and OPN-positive epithelial subtypes showed the tight contact of airway epithelia and TCs. Epithelial OPN regulated the epithelial communication with TCs, and the down-regulation of OPN induced more alterations in transcriptomic profiles than the up-regulation.

CONCLUSION

Our data evidenced that OPN regulated lung epithelial inflammation, injury, and cell communication between epithelium and TCs in acute and chronic lung injury. The conditional control of lung epithelial OPN may be an alternative for preventing and treating epithelial-origin lung inflammation and injury.

The potential roles of cigarette smoke-induced extracellular vesicles in oral leukoplakia

BACKGROUND

The onset of oral leukoplakia (OLK), the most common oral lesion with a high risk of malignant transformation, is closely associated with the exposure of cigarette smoke. Cigarette smoke is a complicated mixture of more than 4500 different chemicals including various oxidants and free radical, which contributes to the onset of immune and inflammatory response or even carcinogenesis. Recent studies have proved that the exposure of cigarette smoke leads to the onset and aggravation of many diseases via significantly changed the production and components of extracellular vesicles. The extracellular vesicles are membrane-enclosed nanosized particles secreted by diverse cells and involved in cell-cell communication because of their ability to deliver a number of bioactive molecules including proteins, lipids, DNAs and RNAs. Getting insight into the mechanisms of extracellular vesicles in regulating OLK upon cigarette smoke stimulation contributes to unravel the pathophysiology of OLK in-depth. However, evidence done on the role of extracellular vesicles in cigarette smoke-induced OLK is still in its infancy.

MATERIALS AND METHODS

Relevant literatures on cigarette smoke, oral leukoplakia and extracellular vesicles were searched in PubMed database.

CONCLUSIONS

In this review, we summarize the recent findings about the function of extracellular vesicles in the pathogenesis of cigarette smoke-induced diseases, and to infer their potential utilizations as diagnostic biomarkers, prognostic evaluation, and therapeutic targets of OLK in the future.

Inhibition of Nur77 expression and translocation by compound B6 reduces ER stress and alleviates cigarette smoke-induced inflammation and injury in bronchial epithelial cells

Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide with inflammation and injury in airway epithelial cells. However, few treatment options effectively reduce severity. We previously found that Nur77 is involved in lipopolysaccharide-induced inflammation and injury of lung tissue. Here, we established an in vitro model of COPD-related inflammation and injury in 16-HBE cells induced by cigarette smoke extract (CSE). In these cells, Nur77 expression and localization to the endoplasmic reticulum (ER) increased following CSE treatment, as did ER stress marker (BIP, ATF4, CHOP) expression, inflammatory cytokine expression, and apoptosis. The flavonoid derivative, named B6, which was shown to be a modulator of Nur77 in previous screen, molecular dynamics simulation revealed that B6 binds strongly to Nur77 through hydrogen bonding and hydrophobic interactions. Treating CSE-stimulated 16-HBE cells with B6 resulted in a reduction of both inflammatory cytokine expression and secretion, as well as attenuated apoptosis. Furthermore, B6 treatment resulted in a decrease in Nur77 expression and translocation to the ER, which was accompanied by a concentration-dependent reduction in the expression of ER stress markers. Meanwhile, B6 played a similar role in CSE-treated BEAS-2B cells. These combined effects suggest that B6 could inhibit inflammation and apoptosis in airway epithelial cells after cigarette smoke stimulation, and support its further development as a candidate intervention for treating COPD-related airway inflammation.

CircRNA_0026344 via miR-21 is involved in cigarette smoke-induced autophagy and apoptosis of alveolar epithelial cells in emphysema

Cigarette smoke (CS), a main source of indoor air pollution, is a primary risk factor for emphysema, and aberrant cellular autophagy is related to the pathogenesis of emphysema. Circular RNAs (circRNAs) affect the expression of mRNAs via acting as microRNA (miRNA) sponges, but their role in emphysema progression is not established. In the present investigation, CS, acting on alveolar epithelial cells, caused higher levels of miR-21, p-ERK, and cleaved-caspase 3 and led to lower levels of circRNA_0026344 and PTEN, which induced autophagy and apoptosis. miR-21 suppressed the expression of PTEN, which was involved in the regulation of autophagy and apoptosis. Further, in alveolar epithelial cells, overexpression of circRNA_0026344 blocked cigarette smoke extract (CSE)-induced autophagy and apoptosis, but this blockage was reversed by upregulation of miR-21 with a mimic. These results demonstrated that, in alveolar epithelial cells, CS decreases circRNA_0026344 levels, which sponge miR-21 to inhibit the miR-21 target, PTEN, which, in turn, activates ERK and thereby promotes autophagy and apoptosis, leading to emphysema. Thus, for emphysema, circRNA_0026344 regulates the PTEN/ERK axis by sponging miR-21, which is associated with the CS-induced autophagy and apoptosis of alveolar epithelial cells. In sum, the present investigation identifies a novel mechanism for CS-induced emphysema and provides information useful for the diagnosis and treatment of CS-induced emphysema.

Smoking-Induced M2-TAMs, via circEML4 in EVs, Promote the Progression of NSCLC through ALKBH5-Regulated m6A Modification of SOCS2 in NSCLC Cells

Lung cancer is a commonly diagnosed disease worldwide, with non-small cell lung cancers (NSCLCs) accounting for ≈ 85% of cases. Cigarette smoke is an environmental exposure promoting progression of NSCLC, but its role is poorly understood. This study reports that smoking-induced accumulation of M2-type tumor-associated macrophages (M2-TAMs) surrounding NSCLC tissues promotes malignancy. Specifically, extracellular vesicles (EVs) from cigarette smoke extract (CSE)-induced M2 macrophages promoted malignancy of NSCLC cells in vitro and in vivo. circEML4 in EVs from CSE-induced M2 macrophages is transported to NSCLC cells, where it reduced the distribution of ALKBH5 in the nucleus by interacting with Human AlkB homolog H5 (ALKBH5), resulting in elevated N6-methyladenosine (m6A) modifications. m6A-seq and RNA-seq revealed suppressor of cytokine signaling 2 (SOCS2)-mediated activation of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway by regulating m6A modification of SOCS2 via ALKBH5. Down-regulation of circEML4 in EVs from CSE-induced M2 macrophages reversed EVs-enhanced tumorigenicity and metastasis in NSCLC cells. Furthermore, this study found that smoking patients showed an increase in circEML4-positive M2-TAMs. These results indicate that smoking-induced M2-TAMs via circEML4 in EVs promote the NSCLC progression through ALKBH5-regulated m6A modification of SOCS2. This study also reveals that circEML4 in EVs from TAMs acts as a diagnostic biomarker for NSCLC, especially for patients with smoking history.

Extracellular vesicles and COPD: foe or friend?

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory airway disease characterized by progressive airflow limitation. The complex biological processes of COPD include protein hydrolysis tissue remodeling, innate immune inflammation, disturbed host-pathogen response, abnormal cellular phenotype conversion, and cellular senescence. Extracellular vesicles (EVs) (including apoptotic vesicles, microvesicles and exosomes), are released by almost all cell types and can be found in a variety of body fluids including blood, sputum and urine. EVs are key mediators in cell-cell communication and can be used by using their bioactive substances (DNA, RNA, miRNA, proteins and other metabolites) to enable cells in adjacent and distant tissues to perform a wide variety of functions, which in turn affect the physiological and pathological functions of the body. Thus, EVs is expected to play an important role in the pathogenesis of COPD, which in turn affects its acute exacerbations and may serve as a diagnostic marker for it. Furthermore, recent therapeutic approaches and advances have introduced EVs into the treatment of COPD, such as the modification of EVs into novel drug delivery vehicles. Here, we discuss the role of EVs from cells of different origins in the pathogenesis of COPD and explore their possible use as biomarkers in diagnosis, and finally describe their role in therapy and future prospects for their application. Graphical Abstract.

Cigarette smoking, by accelerating the cell cycle, promotes the progression of non-small cell lung cancer through an HIF-1α-METTL3-m6A/CDK2AP2 axis

Cigarette smoking killed about 8 million people every year and promoted non-small cell lung cancer (NSCLC). We investigated the molecular mechanism of smoking-promoted NSCLC progression. Relative to non-smokers, NSCLC patients who were smokers had a higher tumor malignancy. For NSCLC cells, cigarette smoke extract (CSE) increased levels of HIF-1α, METTL3, Cyclin E1, and CDK2 and promoted the G1/S transition, which promoted cell proliferation. Down-regulation HIF-1α or METTL3 reversed these effects. meRIP-seq and RNA-seq revealed the m⁶A modification in Cyclin Dependent Kinase 2 Associated Protein 2 (CDK2AP2) mRNA as the key downstream target. Further, for NSCLC cells exposed to CSE, HIF-1α activated METTL3 transcription. Xenografts in nude mice demonstrated that HIF-1α via METTL3 participated in tumor growth. In NSCLC tissues of smokers, protein levels of HIF-1α and METTL3 were higher, and levels of CDK2AP2 were lower. In conclusion, HIF-1α via METTL3 regulation of the m⁶A modification of CDK2AP2 mRNA drives smoking-induced progression of NSCLC through promoting cell proliferation. This is a previously unknown molecular mechanism for smoking-induced NSCLC progression. The results have potential value for treatment of NSCLC, especially for patients who smoke.

EPC-exosomal miR-26a-5p improves airway remodeling in COPD by inhibiting ferroptosis of bronchial epithelial cells via PTGS2/PGE2 signaling pathway

We aimed to investigate whether exosomes (Exo) affected chronic obstructive pulmonary disease (COPD) by influencing ferroptosis of bronchial epithelial cells (BECs) and the mechanisms involved. Here we took the peripheral blood samples of normal subjects and COPD patients, extracted and identified endothelial progenitor cells (EPCs) and EPC-Exo. An animal model of COPD was established. Then human BECs were taken and treated with cigarette smoke extract (CSE) for 24 h to construct a COPD cell model. Next, we screened differentially expressed ferroptosis-related genes in COPD patients by bioinformatics. Bioinformatics predicted the miRNA targeting PTGS2. Then, the mechanism of action of miR-26a-5p and Exo-miR-26a-5p was investigated in vitro. We successfully isolated and identified EPC and Exo. In vitro, EPC alleviated CSE-induced ferroptosis in BECs by transporting Exo. In vivo, Exo alleviated cigarette smoke-induced ferroptosis and airway remodeling in mice. Through further validation, we found that CSE-induced ferroptosis promoted the epithelial-mesenchymal transition (EMT) of BECs. Bioinformatics analysis and validation showed that PTGS2/PGE2 pathway affected CSE-induced ferroptosis in BECs. Meanwhile, miR-26a-5p targeting PTGS2 affected CSE-induced ferroptosis in BECs. Additionally, we found that miR-26a-5p affected CSE-induced BECs EMT. Exo-miR-26a-5p alleviated CSE-induced ferroptosis and EMT. In conclusion, EPC-exosomal miR-26a-5p improved airway remodeling in COPD by inhibiting ferroptosis of BECs via the PTGS2/PGE2 pathway.

IL-11 drives the phenotypic transformation of tracheal epithelial cells and fibroblasts to enhance abnormal repair after tracheal injury

Tracheal stenosis (TS) is a multifactorial and heterogeneous disease that can easily lead to respiratory failure and even death. Interleukin-11 (IL-11) has recently received increased attention as a fibrogenic factor, but its function in TS is uncertain. This study aimed to investigate the role of IL-11 in TS regulation based on clinical samples from patients with TS and a rat model of TS produced by nylon brush scraping. Using lentiviral vectors expressing shRNA (lentivirus-shRNA) targeting the IL-11 receptor (IL-11Rα), we lowered IL-11Rα levels in the rat trachea. Histological and immunostaining methods were used to evaluate the effects of IL-11Rα knockdown on tracheal injury, molecular phenotype, and fibrosis in TS rats. We show that IL-11 was significantly elevated in circulating serum and granulation tissue in patients with TS. In vitro, TGFβ1 dose-dependently stimulated IL-11 secretion from human tracheal epithelial cells (Beas-2b) and primary rat tracheal fibroblasts (PRTF). IL-11 transformed the epithelial cell phenotype to the mesenchymal cell phenotype by activating the β-catenin pathway. Furthermore, IL-11 activated the atypical ERK signaling pathway, stimulated fibroblasts proliferation, and transformed fibroblasts into alpha-smooth muscle actin (α-SMA) positive myofibroblasts. IL-11-neutralizing antibodies (IL-11NAb) or ERK inhibitors (U0126) inhibited IL-11 activity and downregulated fibrotic responses involving TGFβ/SMAD signaling. In vivo, IL-11Rα knockdown rats showed unobstructed tracheal lumen, relatively intact epithelial structure, and significantly reduced granulation tissue proliferation and collagen fiber deposition. Our findings confirm that IL-11 may be a target for future drug prevention and treatment of tracheal stenosis.

Exosomal circCLIP1 regulates PM2.5-induced airway obstruction via targeting SEPT10 in vitro

Fine particulate matter (PM_2.5) exposure correlates with airway obstruction, but the mechanism remains to be fully elucidated. We aim to investigate the role of exosomal circular RNAs (circRNAs)-mediated communication between airway epithelial cells and airway smooth muscle cells in PM_2.5-induced airway obstruction. RNA sequencing revealed that acute PM_2.5 exposure altered the expression profiles of 2904 exosomal circRNAs. Among them, exosomal hsa_circ_0029069 (spliced from CLIP1, thus termed circCLIP1 hereafter) with a loop structure was upregulated by PM_2.5 exposure and mainly encapsulated in exosomes. Then, the biological functions and the underlying mechanisms were explored by Western blot, RNA immunoprecipitation and RNA pull-down, etc. Phenotypically, exosomal circCLIP1 entered recipient cells, inducing mucus secretion in recipient HBE cells and contractility of sensitive HBSMCs. Mechanistically, circCLIP1 was upregulated by METTL3-mediated N⁶-methyladenine (m⁶A) modification in PM_2.5-treated producer HBE cells and exosomes, then enhancing the expression of SEPT10 in recipient HBE cells and sensitive HBSMCs. Our study revealed that exosomal circCLIP1 played a critical role in PM_2.5-induced airway obstruction and provided a new potential biomarker for the assessment of PM_2.5-related adverse effects.

S1PR2 is Important for Cigarette Smoke-induced Pyroptosis in Human Bronchial Epithelial Cells

BACKGROUND

Chronic obstructive pulmonary disease and other respiratory inflammatory diseases are often associated with cigarette smoke exposure. However, the underlying molecular mechanism remains unclear.

AIM OF THE STUDY

This study aimed to investigate the role of sphingosine-1-phosphate receptor 2 (S1PR2) in cigarette smoke extract (CSE)-induced inflammation and pyroptosis in human bronchial epithelial (HBE) cells.

METHODS

CSE was administered to HBE cells and inflammation and pyroptosis were assessed. The mRNA levels of S1PR2, NLRP3, IL-1β, and IL-18 in HBE cells were detected by quantitative RT-PCR. Secreted protein levels of IL-1β and IL-18 in the culture supernatants were detected using enzyme-linked immunosorbent assay. Western blotting was used to measure the levels of S1PR2 and pyroptosis-related proteins (NLRP3, ASC, caspase-1, GSDMD, IL-1β, and IL-18).

RESULTS

Our study revealed an upregulated expression of S1PR2, NLRP3, ASC, caspase-1, GSDMD, IL-1β, and regulated IL-18 in HBE cells after CSE exposure. Genetic blockage of S1PR2 could reverse the increased expression of these proteins related to CSE-induced pyroptosis. Conversely, S1PR2 overexpression increased CSE-induced pyroptosis by upregulating the expression of NLRP3, ASC, caspase-1, GSDMD, IL-1β, and IL-18 in HBE cells.

CONCLUSIONS

Our results revealed that a novel S1PR2 signaling pathway may be involved in the pathogenesis of CSE-induced inflammation and pyroptosis in HBE cells. Thus, S1PR2 inhibitors could be an effective treatment for cigarette smoke-induced airway inflammation and injury.

Circulating exosomal microRNAs as potential prognostic biomarkers in gastrointestinal cancers: a systematic review and meta-analysis

BACKGROUND

Recent reports suggested that circulating exosomal microRNAs (exomiRs) may serve as non-invasive prediction biomarkers in gastrointestinal (GI) cancers, yet their clinicopathological and prognostic values need to be more clarified. Hence, the present meta-analysis was aimed to quantitatively assess the evidence regarding the association between circulating exomiRs and prognosis in GI cancer patients.

METHODS

A comprehensive search was carried out in prominent literature databases, including PubMed, ISI Web of Science, Scopus, and Embase. Odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs) were gathered to evaluate the strength of the association. The quality assessment was investigated through the Newcastle-Ottawa Scale (NOS) and publication bias via Eggers' test and funnel plots.

RESULTS

A total of 47 studies, comprising of 4881 patients, were considered eligible for this meta-analysis. Both up-regulated and down-regulated circulating exomiRs are significantly associated with differentiation (HR = 1.353, P = 0.015; HR = 1.504, P = 0.016), TNM stage (HR = 2.058, P < 0.001; HR = 2.745, P < 0.001), lymph node metastasis (HR = 1.527, P = 0.004; HR = 2.009, P = 0.002), distant metastasis (HR = 2.006, P < 0.001; HR = 2.799, P = 0.002), worse overall survival (OS) (HR = 2.053, P < 0.001; HR = 1.789, P = 0.001) and poorer disease/relapse/progression-free survival (DFS/RFS/PFS) (HR = 2.086, P < 0.001; HR = 1.607, P = 0.001) in GI cancer patients, respectively. In addition, subgroup analyses based on seven subcategories indicated the robustness of the association. The majority of findings were lack of publication bias except for the association between up-regulated exomiRs and OS or DFS/RFS/PFS and for the down-regulated exomiRs and TNM stage.

CONCLUSION

This study supports that up- and down-regulated circulating exomiRs are associated with poorer survival outcomes and could be served as potential prognostic biomarkers in GI cancers. Given the limitations of the current findings, such as significant heterogeneity, more investigations are needed to fully clarify the exomiRs prognostic role.

Analysis of serum exosome microRNAs in the rat model of chronic obstructive pulmonary disease

BACKGROUND

MicroRNAs (miRNAs) play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the molecular mechanisms underlying the function of miRNAs remain to be fully understood. This study aimed to explore the profile of serum exosome-derived miRNAs in the rat model of COPD.

METHODS

We established the COPD rat model by cigarette smoke exposure (CSE). The pulmonary function and morphological changes were analyzed. Serum exosomes were examined by transmission electron microscopy (TEM) and western blotting. The differentially expressed miRNAs between COPD and healthy rats were screened from exosome-derived small RNA library using bioinformatics analysis and experimentally verified in rat lung tissues by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

The pulmonary function indexes in COPD rats were significantly decreased compared to control rats. The typical pathological manifestations of emphysema were observed in COPD rats. Marker proteins (CD9, CD63, and TSG101) and characteristic morphology features were detected in serum exosomes. Fifteen differentially expressed miRNAs were identified in the small RNA library. In addition, we confirmed that the expression of miR-185-5p and miR-182-5p was significantly down-regulated in the lung tissues of COPD rats compared to control rats.

CONCLUSION

The expression of miR-185-5p and miR-182-5p was down-regulated in serum-derived exosomes and lung tissues of COPD rats, indicating that these two miRNAs might be involved in the development of COPD and might serve as potential biomarkers for the diagnosis of COPD.

Dynamic release of neuronal extracellular vesicles containing miR-21a-5p is induced by hypoxia

Hypoxia induces changes in the secretion of extracellular vesicles (EVs) in several non-neuronal cells and pathological conditions. EVs are packed with biomolecules, such as microRNA(miR)-21-5p, which respond to hypoxia. However, the true EV association of miR-21-5p, and its functional or biomarker relevance, are inadequately characterised. Neurons are extremely sensitive cells, and it is not known whether the secretion of neuronal EVs and miR-21-5p are altered upon hypoxia. Here, we characterised the temporal EV secretion profile and cell viability of neurons under hypoxia. Hypoxia induced a rapid increase of miR-21a-5p secretion in the EVs, which preceded the elevation of hypoxia-induced tissue or cellular miR-21a-5p. Prolonged hypoxia induced cell death and the release of morphologically distinct EVs. The EVs protected miR-21a-5p from enzymatic degradation but a remarkable fraction of miR-21a-5p remained fragile and non-EV associated. The increase in miR-21a-5p secretion may have biomarker potential, as high blood levels of miR-21-5p in stroke patients were associated with significant disability at hospital discharge. Our data provides an understanding of the dynamic regulation of EV secretion from neurons under hypoxia and provides a candidate for the prediction of recovery from ischemic stroke.

Extracellular Vesicles' Role in the Pathophysiology and as Biomarkers in Cystic Fibrosis and COPD

In keeping with the extraordinary interest and advancement of extracellular vesicles (EVs) in pathogenesis and diagnosis fields, we herein present an update to the knowledge about their role in cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD). Although CF and COPD stem from a different origin, one genetic and the other acquired, they share a similar pathophysiology, being the CF transmembrane conductance regulator (CFTR) protein implied in both disorders. Various subsets of EVs, comprised mainly of microvesicles (MVs) and exosomes (EXOs), are secreted by various cell types that are either resident or attracted in the airways during the onset and progression of CF and COPD lung disease, representing a vehicle for metabolites, proteins and RNAs (especially microRNAs), that in turn lead to events as such neutrophil influx, the overwhelming of proteases (elastase, metalloproteases), oxidative stress, myofibroblast activation and collagen deposition. Eventually, all of these pathomechanisms lead to chronic inflammation, mucus overproduction, remodeling of the airways, and fibrosis, thus operating a complex interplay among cells and tissues. The detection of MVs and EXOs in blood and biological fluids coming from the airways (bronchoalveolar lavage fluid and sputum) allows the consideration of EVs and their cargoes as promising biomarkers for CF and COPD, although clinical expectations have yet to be fulfilled.

Promising Therapeutic Functions of Bone Marrow Mesenchymal Stem Cells Derived-Exosome in Asthma

Asthma is a chronic inflammatory disturbance of the airways in which many cells and cellular elements are involved. Wheezing, breathlessness, chest tightness, and coughing, especially at night or in the early morning, are typical symptoms of asthma. At present, inhaled corticosteroid (ICS) and long-acting β-agonists (LABAs) are standard treatments for regular management. Oral corticosteroids (OCSs) were recommended for controlling asthma exacerbation but only for a short-term treatment because of the side effects on organs. Biologic therapies have achieved exciting and notable effects in clinical treatment but are not applicable for all phenotypes of asthma. At present, some new approaches are under exploration to lessen side effects and improve curative effects. Studies have revealed that bone marrow mesenchymal stem cells (BMMSCs) hold various curative effects in asthma and may benefit in the long term with high safety. Extracellular vesicles (EVs) enriched in body fluid were characterized as subcomponents of extracellular vesicles and delivered carriers combined with genetic messages in vivo. The therapeutic potential of exosomes has become a research hotspot in many diseases. BMMSC-derived exosomes were considered as the dominant part of BMMSCs in cell-to-cell communications and playing curative effects. Points also hold that BMMSC-Exo could interfere with airway inflammation and airway remolding in asthma via modulating the immune response, regulating gene expression, adjusting the phenotype of macrophage, etc. However, BMMSC-Exo still lacked more clinical trials for evaluating the effects on asthma, and the technology of extraction and purification still needs to be improved for wide use. This review aims to draw the relationship among asthma, BMMSC, and exosome, which may provide innovate ideas for treatment of asthma, and arouse attention about the curative potential of BMMSC-Exo.

Hydrogen sulfide and miR21 are suitable biomarkers of hypoxic exposure

Hypoxia is the reduction of alveolar partial pressure of oxygen ([Formula: see text]). Military members and people who practice recreational activities from moderate to high altitudes are at risk for hypoxic exposure. Hypoxemia's signs and symptoms vary from asymptomatic to severe responses, such as excessive hypoxic ventilatory responses and residual neurobehavioral impairment. Therefore, it is essential to identify hypoxia-induced biomarkers to indicate people with exposure to hypoxia. Advances have been made in understanding physiological responses to hypoxia, including elevations in circulating levels of endothelin 1 (ET-1) and microRNA 21 (miR-21) and reduction in circulating levels of hydrogen sulfide (H2S). Although the levels of these factors change upon exposure to hypoxia, it is unclear if these changes are sustained on return to normoxia. We hypothesize that hypoxia-induced ET-1 and miR-21 remain elevated, whereas hypoxia-reduction in H2S sustains after returning to normoxic conditions. To test this hypothesis, we exposed male rats to 6 h of 12% O2 and measured circulating levels of ET-1 and miR-21, pre, during, and posthypoxia. We found that ET-1 plasma levels increased in response to hypoxia but returned to normal levels within 30 min after the restoration of normoxia. miR-21 plasma levels and transdermal H2S emissions decreased in response to hypoxia, remaining decreased on return to normoxia, thus following the biomarker criteria. Therefore, this study supports a unique role for plasma miR21 and transdermal H2S as hypoxia biomarkers that could be used to identify individuals after exposure to hypoxia.

Gastric cancer stem cell-derived exosomes promoted tobacco smoke-triggered development of gastric cancer by inducing the expression of circ670

As one of the most common malignant cancers in the world, gastric cancer is caused by mang factors among which tobacco smoke is an important risk factor. Gastric cancer stem cells (GCSCs) and the derived exosomes play a key role in the occurrence and development of gastric cancer, and exosomal circRNA is considered as a new regulatory factor in the development of gastric cancer. However, it is unclear whether tobacco smoke can affect exosomes and their transport circRNAs to promote the development of gastric cancer. Herein, we provided a new insight into tobacco smoke promoting the progression of gastric cancer. In the present study, we demonstrated that tobacco smoke-induced exosomes promoted the spheroidizing ability, stemness genes expression, and epithelial-mesenchymal transition (EMT) process of GCSCs. We further found that hsa-circRNA-000670 (circ670) was up-regulated in tissues of gastric cancer patients with smoking history, tobacco smoke-induced GCSCs, and their exosomes. Functional assays have shown that circ670 knockdown inhibited the stemness and EMT process of GCSCs, whereas circ670 overexpression appeared to have an opposite effect. Our findings indicated that exosomal circ670 promotes the development of tobacco smoke-induced gastric cancer, which may provide insight into the mechanism of tobacco smoke promoting the progression of gastric cancer.

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.

Milk Exosomal microRNAs: Postnatal Promoters of β Cell Proliferation but Potential Inducers of β Cell De-Differentiation in Adult Life

Pancreatic β cell expansion and functional maturation during the birth-to-weaning period is driven by epigenetic programs primarily triggered by growth factors, hormones, and nutrients provided by human milk. As shown recently, exosomes derived from various origins interact with β cells. This review elucidates the potential role of milk-derived exosomes (MEX) and their microRNAs (miRs) on pancreatic β cell programming during the postnatal period of lactation as well as during continuous cow milk exposure of adult humans to bovine MEX. Mechanistic evidence suggests that MEX miRs stimulate mTORC1/c-MYC-dependent postnatal β cell proliferation and glycolysis, but attenuate β cell differentiation, mitochondrial function, and insulin synthesis and secretion. MEX miR content is negatively affected by maternal obesity, gestational diabetes, psychological stress, caesarean delivery, and is completely absent in infant formula. Weaning-related disappearance of MEX miRs may be the critical event switching β cells from proliferation to TGF-β/AMPK-mediated cell differentiation, whereas continued exposure of adult humans to bovine MEX miRs via intake of pasteurized cow milk may reverse β cell differentiation, promoting β cell de-differentiation. Whereas MEX miR signaling supports postnatal β cell proliferation (diabetes prevention), persistent bovine MEX exposure after the lactation period may de-differentiate β cells back to the postnatal phenotype (diabetes induction).

Environmental Exposures and Extracellular Vesicles: Indicators of Systemic Effects and Human Disease

PURPOSE OF REVIEW

Environmental pollutants contribute to the pathogenesis of numerous diseases including chronic cardiovascular, respiratory, and neurodegenerative diseases, among others. Emerging evidence suggests that extracellular vesicles (EVs) may mediate the association of environmental exposures with chronic diseases. The purpose of this review is to describe the impact of common environmental exposures on EVs and their role in linking environmental pollutants to the pathogenesis of chronic systemic diseases.

RECENT FINDINGS

Common environmental pollutants including particulate matter, tobacco smoke, and chemical pollutants trigger the release of EVs from multiple systems in the body. Existing research has focused primarily on air pollutants, which alter EV production and release in the lungs and systemic circulation. Air pollutants also impact the selective loading of EV cargo including microRNA and proteins, which modify the cellular function in recipient cells. As a result, pollutant-induced EVs often contribute to a pro-inflammatory and pro-thrombotic milieu, which increases the risk of pollutant-related diseases including obstructive lung diseases, cardiovascular disease, neurodegenerative diseases, and lung cancer. Common environmental exposures are associated with multifaceted changes in EVs that lead to functional alterations in recipient cells and contribute to the pathogenesis of chronic systemic diseases. EVs may represent emerging targets for the prevention and treatment of diseases that stem from environmental exposures. However, novel research is required to expand our knowledge of the biological action of EV cargo, elucidate determinants of EV release, and fully understand the impact of environmental pollutants on human health.

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.

Naringenin suppresses BEAS-2B-derived extracellular vesicular cargoes disorder caused by cigarette smoke extract thereby inhibiting M1 macrophage polarization

Extracellular vesicles (EVs)-mediated epithelium-macrophage crosstalk has been proved to maintain lung homeostasis in cigarette smoke-induced lung diseases such as chronic obstructive pulmonary disease (COPD). In our previous study, we found that EVs derived from cigarette smoke extract (CSE) treated BEAS-2B promoted M1 macrophage polarization, which probably accelerated the development of inflammatory responses. Naringenin has been proved to suppress M1 macrophage polarization, but whether naringenin regulates macrophage polarization mediated by EVs has not been reported. In this study, we firstly found that EVs derived from naringenin and CSE co-treated BEAS-2B significantly inhibited the expression of CD86 and CD80 and the secretion of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, inducible nitric oxide synthase (iNOS), and IL-12 in macrophage induced by EVs derived from CSE-treated BEAS-2B. Further research revealed that naringenin downregulated BEAS-2B-derived EVs miR-21-3p which targeted phosphatase and tensin homolog deleted on chromosome ten/protein kinase B (PTEN/AKT) cascade in macrophages and then suppressed M1 macrophage polarization. Subsequent proteomics suggested that naringenin decreased BEAS-2B-derived EVs poly ADP-ribose polymerase (PARP)1 expression thereby suppressing M1 macrophage polarization probably. Our study provides novel pharmacological references for the mechanism of naringenin in the treatment of cigarette smoke-induced lung inflammatory diseases.