Repression of Toll-like receptor-4 by microRNA-149-3p is associated with smoking-related COPD

Bta-miR-149-3p suppresses inflammatory response in bovine Sertoli cells exposed to microcystin-leucine arginine (MC-LR) through TLR4/NF-kB signaling pathway

This study explored the regulatory role of bta-miR-149-3p in the inflammatory response induced by microcystin-leucine arginine (MC-LR) exposure in bovine Sertoli cells. The research endeavored to enhance the comprehension of the epigenetic mechanisms underlying MC-LR-induced cytotoxicity in Sertoli cells and establish a foundation for mitigating these effects in vitro. In this study, we elucidated the regulatory mechanism of bta-miR-149-3p in the MC-LR-induced inflammatory response by verifying the target gene of bta-miR-149-3p through luciferase assays and treating the cells with a bta-miR-149-3p inhibitor for 24 h. The results demonstrate that nuclear factor κB (NF-κB) acts as a downstream target gene of bta-miR-149-3p, which inhibits the MC-LR-induced inflammatory response in bovine Sertoli cells. This inhibition occurs by regulating the downregulation of tight junction constitutive proteins of the blood-testis barrier (BTB) through the suppression of the TLR-4/NF-κB signaling pathway (p < 0.05) and the up-regulation of the adhesion junction protein β-catenin (p < 0.05). Notably, MC-LR exposure resulted in the up-regulation (p < 0.05) of inflammatory cytokines (IL-6, IL-1β, and NLRP3) and the down-regulation (p < 0.05) of BTB tight junction constitutive proteins (ZO-1, Occludin) in Sertoli cells. Furthermore, the BTB constitutive protein ZO-1 exhibited significant down-regulation in Sertoli cells pretreated with the bta-miR-149-3p inhibitor compared to controls (p < 0.05), while Occludin showed no significant difference from CTNNB1 (p > 0.05). In summary, our findings suggest that bta-miR-149-3p suppresses the MC-LR-induced inflammatory response and alterations in the expression of BTB proteins in bovine Sertoli cells by inhibiting the TLR-4/NF-κB signaling pathway.

Preventive effects of prenatal administration of OM-85/BV on asthma and respiratory infection risk in the offspring: A review of animal models

Asthma is the most common chronic disease in childhood affecting the daily lives of many patients despite current treatment regimens. Therefore, the need for new therapeutic approaches is evident, where a primary prevention strategy is the ultimate goal. Studies of children born to mothers in farming environments have shown a lower risk of respiratory infections and asthma development. Already at birth, these newborns have demonstrated accelerated maturation and upregulation of host defense immune functions suggesting a prenatal transplacental training of the innate immune system through maternal microbial exposure. This mechanism could possibly be utilized to help prevent both respiratory infections and asthma in young children. Human studies exploring the potential preventative effects of pregnancy bacterial lysate treatment on asthma and respiratory infections are lacking, however, this has been studied in experimental studies using mice through administrations of the bacterial lysate OM-85. This review will present the current literature on the immunomodulatory effects relevant for respiratory infections and asthma in the offspring of mice treated with OM-85 throughout pregnancy. Further, the review will discuss the cellular and molecular mechanisms behind these effects. In conclusion, we found promising results of an accelerated immune competence and improved resistance to airway challenges as a result of prenatal bacterial lysate treatment that may pave the way for implementing this in human trials to prevent asthma and respiratory infections.

The regulatory role of differential microRNA expressions on cellular inflammatory factors IL-6 and IL-10 in Echinococcus granulosus-induced anaphylaxis

OBJECTIVE

To determine the pathogenesis and molecular targets of anaphylaxis caused by hydatid cyst fluid leakage.

METHODS

First, Balb/c mice were infected with Echinococcus granulosus, and then the anaphylaxis model was developed. The mice were separated into: anaphylaxis caused by the cystic echinococcosis group (ANPC), the cystic echinococcosis without anaphylaxis group (CE group), and the normal control group (CTRL). Following this, the spleen tissue was collected for microRNA (miRNA) sequencing. Using bioinformatics analysis, differentially expressed miRNAs (DEMs) were identified. Then, through the use of protein-protein interaction (PPI) networks, the key target genes for miRNA regulation associated with echinococcosis-induced anaphylaxis were identified.

RESULTS

ANPC and CE groups have 29 and 39 DEMs compared to the CTRL group, respectively. Based on these 25 DEMs, interactions between miRNA and mRNA were screened, and 174 potential target genes were identified. We performed gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis on these 174 target genes, and the results revealed that the three pathways with the highest enrichment were the PI3K-Akt signaling pathway, FoxO signaling pathway, and Focal adhesion. The interaction analysis of PPI and miRNA-hub gene networks revealed that interleukin 6 (IL-6) was regulated by miR-146a-5p and miR-149-5p, while IL-10 was regulated by miR-29b-3p and miR-29c-3. Using reverse transcription polymerase chain reaction, we found that the miRNAs regulating IL-6 and IL-10 were significantly upregulated in the ANPC group, and there are three pathways involved in that process: Pathways of PI3K-Akt signaling, FoxO signaling, and Focal adhesion. IL-6 and IL-10 play an important role in cellular pyroptosis and apoptosis. Therefore, the aforementioned results provide significant reference value for elucidating the mechanism of cellular pyroptosis and apoptosis in echinococcosis-induced anaphylaxis, and for formulating tissue and organ protection strategies for patients with cystic echinococcosis when anaphylaxis is triggered by hydatid cyst rupture.

Lung microRNAs Expression in Lung Cancer and COPD: A Preliminary Study

Non-small cell lung cancer (NSCLC) is one of the deadliest diseases worldwide and represents an impending burden on the healthcare system. Despite increasing attention, the mechanisms underlying tumorigenesis in cancer-related diseases such as COPD remain unclear, making novel biomarkers necessary to improve lung cancer early diagnosis. MicroRNAs (miRNAs) are short non-coding RNA that interfere with several pathways and can act as oncogenes or tumor suppressors. This study aimed to compare miRNA lung expression between subjects with NSCLC and COPD and healthy controls to obtain the miRNA expression profile by analyzing shared pathways. Lung specimens were collected from a prospective cohort of 21 sex-matched subjects to determine the tissue miRNA expression of hsa-miR-34a-5p, 33a-5p, 149-3p, 197-3p, 199-5p, and 320a-3p by RT-PCR. In addition, an in silico prediction of miRNA target genes linked to cancer was performed. We found a specific trend for has-miR-149-3p, 197-3p, and 34a-5p in NSCLC, suggesting their possible role as an index of the tumor microenvironment. Moreover, we identified novel miRNA targets, such as the Cyclin-Dependent Kinase (CDK) family, linked to carcinogenesis by in silico analysis. In conclusion. this study identified lung miRNA signatures related to the tumorigenic microenvironment, suggesting their possible role in improving the evaluation of lung cancer onset.

Epigenetic and transcriptomic characterization of maternal-fetal interface in patients with recurrent miscarriage via an integrated multi-omics approach

Recurrent miscarriage (RM) occurs in 2.5 % of women aiming at childbirth, with unknown etiology in half of the cases. To identify the molecular features, an integrative study combining bioinformatics and multi-omics from GEO database was performed in these patients. Two datasets (GSE43256 and GSE73025) were integrated to indicate 1657 differentially expressed genes (DE-genes) in villus of females with RM. DE-genes in villus of females with RM mainly focused on cell growth and development. On the other hand, 230 DE-genes in decidua of RM patients were retrieved from GSE113790, and the DE-genes were involved in diverse functions, including transport of nutrients, immune response, extracellular matrix remodeling, and angiogenesis. Additionally, the results of immunologic signatures indicated that immune regulation played roles in both decidua and villus of RM. Interestingly, C1q and TNF related 7 (C1QTNF7), acquired from the intersection of decidua and villus datasets, is crucial in maintaining immune homeostasis, so is its upstream miRNA (miR-149-3p). The enhanced expression of C1QTNF7 in macrophages might inhibit the proliferation and migration of trophoblasts, and further result in pregnancy loss. The present study suggests C1QTNF7 might be a new target for the diagnosis and treatment of RM, but more basic researches are further required to illustrate its mechanism in RM.

Association of toll-like receptors polymorphisms with COPD risk in Chinese population

Background: Previous studies have reported that the Toll-like receptors (TLRs) are related with the progress of chronic obstructive pulmonary disease (COPD). We aimed to explore the association of TLRs single nucleotide polymorphisms (SNPs) and COPD risk. Methods: 170 COPD patients and 181 healthy controls were enrolled in this case-control study. MassARRAY platform was used for genotyping seven tagging SNPs (TLR2: rs3804100, rs4696480, rs3804099; TLR3: rs3775290, rs3775291, rs5743305; TLR9: rs352140) of TLRs. The correlations between the SNPs and COPD risk were determined using logistic regression. Results: We found that the rs3775291 of TLR3 significant decreased the risk of COPD (TT versus CC: non-adjusted OR = 0.329, 95% CI = 0.123-0.879, p = 0.027). In the genetic models analysis, the rs3775291 was associated with a decreased effect of COPD based on the recessive model (TT versus CC/CT: non-adjusted OR = 0.377, 95% CI = 0.144-0.988 p = 0.047). The rs4696480 of TLR2 gene was associated with a decreased risk of COPD after adjustment by age and gender (TA versus AA: adjusted OR = 0.606, 95% CI = 0.376-0.975, p = 0.039). Conclusion: Our study showed that genetic variants in TLRs were associated with risk of COPD. The rs3775291 and rs4696480 may act as a potential biomarker for predicting the risk of COPD in Chinese population.

ISGylation is induced in neurons by demyelination driving ISG15-dependent microglial activation

The causes of grey matter pathology and diffuse neuron injury in MS remain incompletely understood. Axonal stress signals arising from white matter lesions has been suggested to play a role in initiating this diffuse grey matter pathology. Therefore, to identify the most upstream transcriptional responses in neurons arising from demyelinated axons, we analyzed the transcriptome of actively translating neuronal transcripts in mouse models of demyelinating disease. Among the most upregulated genes, we identified transcripts associated with the ISGylation pathway. ISGylation refers to the covalent attachment of the ubiquitin-like molecule interferon stimulated gene (ISG) 15 to lysine residues on substrates targeted by E1 ISG15-activating enzyme, E2 ISG15-conjugating enzymes and E3 ISG15-protein ligases. We further confirmed that ISG15 expression is increased in MS cortical and deep gray matter. Upon investigating the functional impact of neuronal ISG15 upregulation, we noted that ISG15 expression was associated changes in neuronal extracellular vesicle protein and miRNA cargo. Specifically, extracellular vesicle-associated miRNAs were skewed toward increased frequency of proinflammatory and neurotoxic miRNAs and decreased frequency of anti-inflammatory and neuroprotective miRNAs. Furthermore, we found that ISG15 directly activated microglia in a CD11b-dependent manner and that microglial activation was potentiated by treatment with EVs from neurons expressing ISG15. Further study of the role of ISG15 and ISGylation in neurons in MS and neurodegenerative diseases is warranted.

Transcription Factor p300 Regulated miR-451b Weakens the Cigarette Smoke Extract-Induced Cellular Stress by Targeting RhoA/ROCK2 Signaling

Background

A previous study identified miR-451b as a potential biomarker in smoker with or without chronic obstructive pulmonary disease (COPD). However, the function and molecular mechanisms of miR-451b in the pathogenesis of COPD remain elusive.

Methods

Macrophages and lung fibroblasts were exposed to 10% cigarette smoke extract (CSE) solution for 24 h. Expression miR-451b and its potential transcription factor p300 were detected. The association between p300 and miR-451b, miR-451b and RhoA was validated by luciferase reporter assay. The release of IL-12 and TNF-αby macrophages was measured by ELISA assay, and Transwell assay was performed to analyze its migration and invasion. Collagen protein of fibroblasts was detected by Western blotting.

Results

Results showed that p300 and miR-451b was downregulated, while RhoA was upregulated in CSE-induced macrophages and lung fibroblasts. The stimulation of CSE promoted the degradation of p300 by ubiquitination, and RhoA was confirmed as the target gene of miR-451b. MiR-451b overexpression significantly decreased the release of IL-12 and TNF-α, downregulated the expression of RhoA, ROCK2, and p65, and suppressed cell migration and invasion in CES-induced macrophages. In addition, miR-451b overexpression decreased the expression of RhoA, ROCK2, COL1A1, and COL2A1 in lung fibroblasts.

Conclusions

Our data suggest that p300/miR-451b protects against CSE-induced cell stress possibly through downregulating RhoA/ROCK2 pathway.

The role of HMGB1/RAGE/TLR4 signaling pathways in cigarette smoke-induced inflammation in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common chronic respiratory disease with irreversible and continuous progression. It has become the fifth most burdensome disease and the third most deadly disease globally. Therefore, the prevention and treatment of COPD are urgent, and it is also important to clarify the pathogenesis of it. Smoking is the main and most common risk factor for COPD. Cigarette smoke (CS) can cause lung inflammation and other pathological mechanisms in the airways and lung tissue. Airway inflammation is one of the important mechanisms leading to the pathogenesis of COPD. Recent studies have shown that high mobility group box 1 (HMGB1) is involved in the occurrence and development of respiratory diseases, including COPD. HMGB1 is a typical damage-associated molecular pattern (DAMP) protein, which mainly exerts its activity by binding to the receptor for advanced glycation end products (RAGE) and toll-like receptor 4 (TLR4) and further participate in the process of airway inflammation. Studies have shown that the abnormal expression of HMGB1, RAGE, and TLR4 are related to inflammation in COPD. Herein, we discuss the roles of HMGB1, RAGE, and TLR4 in CS/cigarette smoke extract-induced inflammation in COPD, providing a new target for the diagnosis, treatment and prevention of COPD.

Joint detection of miR ‐149‐3p and hepcidin predicts the onset of obstructive sleep apnea syndrome in obese patients

Background

Methods

Results

Conclusion

The Novel Regulatory Role of the lncRNA–miRNA–mRNA Axis in Chronic Inflammatory Airway Diseases

Chronic inflammatory airway diseases, characterized by airway inflammation and airway remodelling, are increasing as a cause of morbidity and mortality for all age groups and races across the world. The underlying molecular mechanisms involved in chronic inflammatory airway diseases have not been fully explored. MicroRNAs (miRNAs) and long noncoding RNAs (lncRNAs) have recently attracted much attention for their roles in the regulation of a variety of biological processes. A number of studies have confirmed that both lncRNAs and miRNAs can regulate the initiation and progression of chronic airway diseases by targeting mRNAs and regulating different cellular processes, such as proliferation, apoptosis, inflammation, migration, and epithelial–mesenchymal transition (EMT). Recently, accumulative evidence has shown that the novel regulatory mechanism underlying the interaction among lncRNAs, miRNAs and messenger RNAs (mRNAs) plays a critical role in the pathophysiological processes of chronic inflammatory airway diseases. In this review, we comprehensively summarized the regulatory roles of the lncRNA–miRNA–mRNA network in different cell types and their potential roles as biomarkers, indicators of comorbidities or therapeutic targets for chronic inflammatory airway diseases, particularly chronic obstructive pulmonary disease (COPD) and asthma.

Epigenetic Mechanisms in Parenchymal Lung Diseases: Bystanders or Therapeutic Targets?

Epigenetic responses due to environmental changes alter chromatin structure, which in turn modifies the phenotype, gene expression profile, and activity of each cell type that has a role in the pathophysiology of a disease. Pulmonary diseases are one of the major causes of death in the world, including lung cancer, idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), pulmonary hypertension (PH), lung tuberculosis, pulmonary embolism, and asthma. Several lines of evidence indicate that epigenetic modifications may be one of the main factors to explain the increasing incidence and prevalence of lung diseases including IPF and COPD. Interestingly, isolated fibroblasts and smooth muscle cells from patients with pulmonary diseases such as IPF and PH that were cultured ex vivo maintained the disease phenotype. The cells often show a hyper-proliferative, apoptosis-resistant phenotype with increased expression of extracellular matrix (ECM) and activated focal adhesions suggesting the presence of an epigenetically imprinted phenotype. Moreover, many abnormalities observed in molecular processes in IPF patients are shown to be epigenetically regulated, such as innate immunity, cellular senescence, and apoptotic cell death. DNA methylation, histone modification, and microRNA regulation constitute the most common epigenetic modification mechanisms.

Role of Non-Coding RNAs in Post-Transcriptional Regulation of Lung Diseases

Non-coding RNAs (ncRNAs), notably microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), have recently gained increasing consideration because of their versatile role as key regulators of gene expression. They adopt diverse mechanisms to regulate transcription and translation, and thereby, the function of the protein, which is associated with several major biological processes. For example, proliferation, differentiation, apoptosis, and metabolic pathways demand fine-tuning for the precise development of a specific tissue or organ. The deregulation of ncRNA expression is concomitant with multiple diseases, including lung diseases. This review highlights recent advances in the post-transcriptional regulation of miRNAs and lncRNAs in lung diseases such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, and idiopathic pulmonary fibrosis. Further, we also discuss the emerging role of ncRNAs as biomarkers as well as therapeutic targets for lung diseases. However, more investigations are required to explore miRNAs and lncRNAs interaction, and their function in the regulation of mRNA expression. Understanding these mechanisms might lead to early diagnosis and the development of novel therapeutics for lung diseases.

Identifying miRNA Modules and Related Pathways of Chronic Obstructive Pulmonary Disease Associated Emphysema by Weighted Gene Co-Expression Network Analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a heterogeneous chronic inflammatory disease characterized by progressive airflow limitation that causes high morbidity and mortality. MicroRNA, a short-chain noncoding RNA, regulates gene expression at the transcriptional level. microRNA modules with a role in the pathogenesis of COPD may serve as COPD biomarkers.

METHODS

We downloaded the GSE33336 microarray data set from the Gene Expression Omnibus (GEO) database, the data are derived from 29 lung samples of patients with emphysema undergoing curative resection for lung cancer. We used weighted gene co-expression network analysis (WGCNA) to construct co-expression modules and detect trait-related microRNA modules. We used the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to predict the biological function of the interest modules, and we screened out candidate hub microRNAs based on their module membership (MM) value and top proteins on the results of the protein-protein interaction (PPI) network.

RESULTS

Three microRNA modules (royal blue, light yellow and grey60) were highly associated with COPD. Axon guidance, proteoglycans in cancer and mitogen-activated protein kinases (MAPK) signaling pathway were common pathways in these three modules. Keratin18 (KRT18) was the top protein in our study. miR-452, miR-149, miR-133a, miR-181a and miR-421 in hub microRNAs may play a role in COPD.

CONCLUSION

These findings provide evidence for the role of miRNAs in COPD and identify biomarker candidates.

MiRNA-149 as a Candidate for Facial Clefting and Neural Crest Cell Migration

Nonsyndromic cleft lip with or without palate (nsCL/P) ranks among the most common human birth defects and has a multifactorial etiology. Human neural crest cells (hNCC) make a substantial contribution to the formation of facial bone and cartilage and are a key cell type in terms of nsCL/P etiology. Based on increasing evidence for the role of noncoding regulatory mechanisms in nsCL/P, we investigated the role of hNCC-expressed microRNAs (miRNA) in cleft development. First, we conducted a systematic analysis of miRNAs expressed in human-induced pluripotent stem cell-derived hNCC using Affymetrix microarrays on cell lines established from 4 unaffected donors. These analyses identified 152 candidate miRNAs. Based on the hypothesis that candidate miRNA loci harbor genetic variation associated with nsCL/P risk, the genomic locations of these candidates were cross-referenced with data from a previous genome-wide association study of nsCL/P. Associated variants were reanalyzed in independent nsCL/P study populations. Jointly, the results suggest that miR-149 is implicated in nsCL/P etiology. Second, functional follow-up included in vitro overexpression and inhibition of miR-149 in hNCC and subsequent analyses at the molecular and phenotypic level. Using 3'RNA-Seq, we identified 604 differentially expressed (DE) genes in hNCC overexpressing miR-149 compared with untreated cells. These included TLR4 and JUNB, which are established targets of miR-149, and NOG, BMP4, and PAX6, which are reported nsCL/P candidate genes. Pathway analyses revealed that DE genes were enriched in pathways including regulation of cartilage development and NCC differentiation. At the cellular level, distinct hNCC migration patterns were observed in response to miR-149 overexpression. Our data suggest that miR-149 is involved in the etiology of nsCL/P via its role in hNCC migration.

Circ-HACE1 Aggravates Cigarette Smoke Extract-Induced Injury in Human Bronchial Epithelial Cells via Regulating Toll-Like Receptor 4 by Sponging miR-485-3p

Background

Smoking is the most common cause of chronic obstructive pulmonary disease (COPD), and the early diagnosis for COPD remains poor. Exploring the molecular mechanism and finding feasible biomarkers will be beneficial for clinical management of COPD. Circular RNAs (circRNAs) are noncoding RNAs that act as miRNA sponges to regulate the expression levels of genes, leading to the changes of cellular phenotypes and disease progression. CircRNA HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1 (circ-HACE1) was abnormally expressed after the induction of cigarette smoke extract (CSE) in cell model. This study was performed to explore its function and mechanism in COPD.

Methods

Circ-HACE1, microRNA-485-3p (miR-485-3p) and toll-like receptor 4 (TLR4) detection was performed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis/cell cycle were respectively examined using cell counting kit-8 (CCK-8) and flow cytometry. Inflammatory cytokines were determined by enzyme-linked immunosorbent assay (ELISA). Oxidative stress was evaluated through the measurement of malondialdehyde (MDA) and superoxide dismutase (SOD). The target binding analysis was conducted via dual-luciferase reporter assay. Western blot was employed for protein expression detection of TLR4.

Results

Circ-HACE1 was overexpressed in smokers or smokers with COPD and CSE upregulated circ-HACE1 expression in 16HBE cells. Knockdown of circ-HACE1 attenuated CSE-stimulated cell viability and cell cycle repression, as well as the enhancement of cell apoptosis, inflammatory response and oxidative stress. MiR-485-3p was a target of circ-HACE1. Circ-HACE1 regulated CSE-induced cell injury via targeting miR-485-3p. TLR4 was a downstream target of miR-485-3p, and miR-485-3p inhibited the CSE-induced cell damages by directly downregulating the level of TLR4. Circ-HACE1/miR-485-3p regulated TLR4 expression in CSE-treated 16HBE cells, and TLR4 overexpression also reversed all effects of si-circ-HACE1 on CSE-treated 16HBE cells.

Conclusion

These findings elucidated that circ-HACE1 contributed to the CSE-induced cell damages in COPD cell models via regulating TLR4 by acting as the sponge of miR-485-3p.

MicroRNAs as Potential Regulators of Immune Response Networks in Asthma and Chronic Obstructive Pulmonary Disease

Chronic respiratory diseases (CRDs) are an important factor of morbidity and mortality, accounting for approximately 6% of total deaths worldwide. The main CRDs are asthma and chronic obstructive pulmonary disease (COPD). These complex diseases have different triggers including allergens, pollutants, tobacco smoke, and other risk factors. It is important to highlight that although CRDs are incurable, various forms of treatment improve shortness of breath and quality of life. The search for tools that can ensure accurate diagnosis and treatment is crucial. MicroRNAs (miRNAs) are small non-coding RNAs and have been described as promising diagnostic and therapeutic biomarkers for CRDs. They are implicated in multiple processes of asthma and COPD, regulating pathways associated with inflammation, thereby showing that miRNAs are critical regulators of the immune response. Indeed, miRNAs have been found to be deregulated in several biofluids (sputum, bronchoalveolar lavage, and serum) and in both structural lung and immune cells of patients in comparison to healthy subjects, showing their potential role as biomarkers. Also, miRNAs play a part in the development or termination of histopathological changes and comorbidities, revealing the complexity of miRNA regulation and opening up new treatment possibilities. Finally, miRNAs have been proposed as prognostic tools in response to both conventional and biologic treatments for asthma or COPD, and miRNA-based treatment has emerged as a potential approach for clinical intervention in these respiratory diseases; however, this field is still in development. The present review applies a systems biology approach to the understanding of miRNA regulatory networks in asthma and COPD, summarizing their roles in pathophysiology, diagnosis, and treatment.

Transplacental Innate Immune Training via Maternal Microbial Exposure: Role of XBP1-ERN1 Axis in Dendritic Cell Precursor Programming

We recently reported that offspring of mice treated during pregnancy with the microbial-derived immunomodulator OM-85 manifest striking resistance to allergic airways inflammation, and localized the potential treatment target to fetal conventional dendritic cell (cDC) progenitors. Here, we profile maternal OM-85 treatment-associated transcriptomic signatures in fetal bone marrow, and identify a series of immunometabolic pathways which provide essential metabolites for accelerated myelopoiesis. Additionally, the cDC progenitor compartment displayed treatment-associated activation of the XBP1-ERN1 signalling axis which has been shown to be crucial for tissue survival of cDC, particularly within the lungs. Our forerunner studies indicate uniquely rapid turnover of airway mucosal cDCs at baseline, with further large-scale upregulation of population dynamics during aeroallergen and/or pathogen challenge. We suggest that enhanced capacity for XBP1-ERN1-dependent cDC survival within the airway mucosal tissue microenvironment may be a crucial element of OM-85-mediated transplacental innate immune training which results in postnatal resistance to airway inflammatory disease.

Long non-coding RNA maternally expressed gene regulates cigarette smoke extract induced lung inflammation and human bronchial epithelial apoptosis via miR-149-3p

Chronic obstructive pulmonary disease (COPD) has become a significant public health risk. Long non-coding RNAs (lncRNAs) have been identified as important factors involved in the proliferation, apoptosis and inflammatory cytokine expression of lung cells. Peripheral blood samples from 66 subjects (18 non-smokers, 24 smokers without COPD and 28 smokers with COPD) and HBE135-E6E7 cell treated with cigarette smoke extract (CSE) or not were used as the research object. The aim of the present study was to investigate the underlying mechanism of lncRNA maternally expressed gene 3 (MEG3) in COPD. Following transfection with microRNA (miR)-149-3p mimics, miR-negative control mimics, miR-149-3p inhibitor, miR-negative control inhibitor, small interfering (si)RNA targeting MEG3 (si-MEG3) and si-negative control (si-NC), levels of MEG3 and microRNA (miR)-149-3p were detected using reverse transcription-quantitative PCR, Proliferation and apoptosis were examined using the Cell Counting Kit-8 and flow cytometry assays, respectively. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Protein levels of B-cell lymphoma-2 (Bcl-2), cleaved-caspase-3, cleaved-caspase-9, phosphorylated (p)-p65, total (t)-p65, p-lkBα and t-lkBα were measured by western blotting. Luciferase assay was conducted to examine the relationship between MEG3 and miR-149-3p. LncRNA MEG3 was highly expressed, whereas miR-149-3p expression was downregulated in smokers with COPD peripheral blood samples, compared with non-smokers and smokers without COPD samples. Compared with untreated human bronchial epithelial (HBE) cells, MEG3 expression was increased in cigarette smoke extract (CSE)-treated HBE cells. Compared with CSE-treated HBE cells transfected with si-NC, MEG3 knockdown promoted cell proliferation and inhibited apoptosis in CSE-treated HBE cells transfected with si-MEG3, and it also decreased the levels of IL-6, TNF-α, Bcl-2 and increased cleaved-caspase-3 and cleaved-caspase-9 in CSE-treated HBE cells transfected with si-MEG3. The luciferase assay demonstrated that miR-149-3p has target sites for MEG3. MEG3 was demonstrated to regulate the NF-κB signaling pathway by sponging miR-149-3p in CSE-treated HBE cells. In conclusion, these findings suggested that MEG3 promoted proliferation and inhibited apoptosis by regulating the NF-κB signal pathway via miR-149-3p in CSE-treated HBE cells. These results provide an insight for further verification and understanding of the molecular basis of COPD.

miRNA-486-5p Promotes COPD Progression by Targeting HAT1 to Regulate the TLR4-Triggered Inflammatory Response of Alveolar Macrophages

Purpose

The aim of this study was to investigate the role of miRNA-486-5p in chronic obstructive pulmonary disease (COPD) progression and the underlying molecular mechanisms.

Materials and Methods

Aberrant miRNA expression profiles between smokers and nonsmokers, and those between COPD patients and normal subjects were analyzed using microarray datasets and reverse-transcriptase quantitative polymerase chain reaction (qPCR). Enzyme-linked immunosorbent assay was used to determine the levels of inflammatory cytokines in cell supernatants. Expression levels of inflammatory cytokines, HAT1, TLR4, and miR-486-5p, were determined using qPCR or Western blotting. Luciferase reporter assays and fluorescence in situ hybridization were used to confirm the regulatory interaction between miR-486-6p and HAT1.

Results

miR-486-5p was significantly upregulated in the COPD and smoker groups compared to the control group, as demonstrated using bioinformatics analysis and validated using qPCR assay of alveolar macrophages and peripheral monocytes. Moreover, miR-486-5p expression was significantly correlated with the expression of IL-6, IL-8, TNF-α, and IFN-γ. Luciferase reporter assays confirmed that miR-486-5p directly targeted HAT1, and cellular localization showed that miR-486-5p and HAT1 were highly expressed in the cytoplasm. miR-486-5p overexpression led to a significant upregulation of TLR4 and a significant downregulation of HAT1. Inversely, miR-486-5p inhibition led to a significant downregulation of TLR4 and a significant upregulation of HAT1. HAT1 knockdown using siRNA significantly upregulated the expression of TLR4, IL-6, IL-8, TNF-α, and IFN-γ.

Conclusion

miR-486-5p was differentially expressed in the alveolar macrophages of COPD patients. miR-486-5p overexpression may enhance the TLR4-triggered inflammatory response in COPD patients by targeting HAT1.

Mechanisms of the lipopolysaccharide-induced inflammatory response in alveolar epithelial cell/macrophage co-culture

The interaction between alveolar epithelial cells (EpCs) and macrophages (MPs) serves an important role in initiating and maintaining inflammation in chronic pulmonary diseases. The aim of the present study was to investigate the molecular mechanisms of the inflammatory response in co-cultured EpCs and MPs. Briefly, a co-culture system of A549 (EpCs) and THP-1 (monocyte/MPs) cells was established in a filter-separated Transwell plate to evaluate the inflammatory response. Following lipopolysaccharide (LPS) treatment, cytokine levels were measured using ELISAs, NF-κB transcription factor activity was detected using EMSA and protein expression levels were analyzed using Western blot assays subsequently in EpCs and MPs. Co-cultured EpCs/MPs were found to secrete increased levels of interleukin (IL)-6, IL-1β, IL-8 and tumor necrosis factor (TNF)-α following LPS exposure for 6, 12, 24 and 48 h compared with either EpC or MP monocultures. Concurrently, NF-κB was revealed to be activated in MPs at 6 and 12 h, and in EpCs at 24 h. NF-κB DNA binding, Toll-like receptor 4 expression levels and the p65 phosphorylation status were also increased, which may contribute to the inflammatory response in the EpC/MP co-cultures. Notably, cytokine levels decreased following the inhibition of NF-κB expression with pyrrolidinedithiocarbamate. In conclusion, the present study successfully established an EpC/MP co-culture system using LPS, which may be a useful model for studying chronic inflammation in vitro.

A meta-analysis of microRNAs expressed in human aerodigestive epithelial cultures and their role as potential biomarkers of exposure response to nicotine-containing products

The expression of some microRNAs (miRNA) is modulated in response to cigarette smoke (CS), which is a leading cause of major preventable diseases. However, whether miRNA expression is also modulated by the aerosol/extract from potentially reduced-risk products is not well studied. The present work is a meta-analysis of 12 in vitro studies in human organotypic epithelial cultures of the aerodigestive tract (buccal, gingival, bronchial, nasal, and small airway epithelia). These studies compared the effects of exposure to aerosols from electronic vapor (e-vapor) products and heated tobacco products, and to extracts from Swedish snus products (in the present work, will be referred to as reduced-risk products [RRPs]) on miRNA expression with the effects of exposure to CS or its total particulate matter fraction. This meta-analysis evaluated 12 datasets of a total of 736 detected miRNAs and 2775 exposed culture inserts. The t-distributed stochastic neighbor embedding method was used to find similarities across the diversity of miRNA responses characterized by tissue type, exposure type, and product concentration. The CS-induced changes in miRNA expression in gingival cultures were close to those in buccal cultures; similarly, the alterations in miRNA expression in small airway, bronchial, and nasal tissues resembled each other. A supervised clustering was performed to identify miRNAs exhibiting particular response patterns. The analysis identified a set of miRNAs whose expression was altered in specific tissues upon exposure to CS (e.g., miR-125b-5p, miR-132-3p, miR-99a-5p, and 146a-5p). Finally, we investigated the impact of RRPs on miRNA expression in relation to that of CS by calculating the response ratio r between the RRP- and CS-induced alterations at an individual miRNA level, showing reduced alterations in miRNA expression following RRP exposure relative to CS exposure (94 % relative reduction). No specific miRNA response pattern indicating exposure to aerosols from heated tobacco products and e-vapor products, or extracts from Swedish snus was identifiable.

The effect of smoking on latent tuberculosis infection susceptibility in high risk individuals in Iran

Tuberculosis has been declared as a global emergency. Latent tuberculosis infection (LTBI) is a state in which host immunity cannot completely eradicate Mycobacterium tuberculosis. Cigarette smoke increases the risk of respiratory infections, such a TB, as it has adverse effects on respiratory immune function. In this cross-sectional study, which was performed from 2016 to 2017, 31 patients with newly diagnosed lung cancer, 63 Chronic obstructive pulmonary disease (COPD), 46 with problems in respiratory system, and 40 healthy subjects were studied. Demographic data of all subjects were recorded via a questionnaire. IGRAs (Interferon-γ release assays) were used to determine LTBI. We showed that smoking has significant odds ratio for COPD patients (OR: 4.58, 95% CI: 1.93-10.87). Also, the concordance of smoking with COPD (OR: 22, 95% CI: 2.7-179.2), lung cancer (OR: 10, 95% CI: 1.03-97), and other respiratory diseases (OR: 4.54, 95% CI: 1.93-10.87) is a significant risk factor for the presence of LTBI whereas the existence of LTBI in the study groups did not show any significant odds ratio. This study is the first to analyze the relationship between smoking in patients with respiratory diseases and LTBI susceptibility in Iran by IGRAs, which proposes cigarette smoking as a powerful risk factor for LTBI.

MicroRNAs in chronic airway diseases: Clinical correlation and translational applications

MicroRNAs (miRNAs) are short single-stranded RNAs that have pivotal roles in disease pathophysiology through transcriptional and translational modulation of important genes. It has been implicated in the development of many diseases, such as stroke, cardiovascular conditions, cancers and inflammatory airway diseases. There is recent evidence that miRNAs play important roles in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD), and could help to distinguish between T2-low (non-eosinophilic, steroid-insensitive) versus T2-high (eosinophilic, steroid-sensitive) disease endotypes. As these are the two most prevalent chronic respiratory diseases globally, with rising disease burden, miRNA research might lead to the development of new diagnostic and therapeutic targets. Research involving miRNAs in airway disease is challenging because: (i) asthma and COPD are heterogeneous inflammatory airway diseases; there are overlapping but distinct inter- and intra-disease differences in the immunological pathophysiology, (ii) there exists more than 2000 known miRNAs and a single miRNA can regulate multiple targets, (iii) differential effects of miRNAs could be present in different cellular subtypes and tissues, and (iv) dysregulated miRNA expression might be a direct consequence of an indirect effect of airway disease onset or progression. As miRNAs are actively secreted in fluids and remain relatively stable, they have the potential for biomarker development and therapeutic targets. In this review, we summarize the preclinical data on potential miRNA biomarkers that mediate different pathophysiological mechanisms in airway disease. We discuss the framework for biomarker development using miRNA and highlight the need for careful patient characterization and endotyping in the screening and validation cohorts, profiling both airway and blood samples to determine the biological fluids of choice in different disease states or severity, and adopting an untargeted approach. Collaboration between the various stakeholders - pharmaceutical companies, laboratory professionals and clinician-scientists is crucial to reduce the difficulties and cost required to bring miRNA research into the translational stage for airway diseases.

Cigarette smoke promotes chronic obstructive pulmonary disease (COPD) through the miR-130a/Wnt1 axis

Cigarette smoke (CS) is a crucial factor in chronic obstructive pulmonary disease (COPD). Wnt/β-catenin signaling deregulation may further contribute to COPD progression. The deregulation and dysfunction of miRNAs in COPD have been reported. Investigating the deregulated miRNAs and their potential role in COPD progression may provide novel strategies for COPD treatment. In the present study, we analyzed significantly differentially-expressed miRNAs in COPD according to GSE44531 and miR-130a was selected. We revealed the upregulation of miR-130a in COPD, both in cigarette smoke extract (CSE)-treated BEAS-2B cells and CS-exposed mice. MiR-130a negatively regulated three critical factors in Wnt/β-catenin signaling, Wnt1, β-Catenin, and LEF1. MiR-130a inhibition rescued CSE-blocked activation of Wnt/β-catenin signaling in vitro. MiR-130a targets WNT1 3'UTR to inhibit its expression. Moreover, in CSE-stimulated BEAS-2B cells, miR-130a overexpression aggravated, while miR-130a inhibition partially attenuated CSE-caused suppression on cell migration and proliferation. MiR-130a aggravates CSE-induced cellular injury in BEAS-2B cells by targeting Wnt signaling. In summary, miR-130a has a pathogenetic role in CS-induced COPD and regulates Wnt/β-catenin signaling via targeting Wnt1. Our findings indicate that miR-130a is a potential therapeutic target for the treatment of CS-induced COPD.

miRNAs in Lung Development and Diseases

The development of the lung involves a diverse group of molecules that regulate cellular processes, organ formation, and maturation. The various stages of lung development are marked by accumulation of small RNAs that promote or repress underlying mechanisms, depending on the physiological environment in utero and postnatally. To some extent, the pathogenesis of various lung diseases is regulated by small RNAs. In this review, we discussed miRNAs regulation of lung development and diseases, that is, COPD, asthma, pulmonary fibrosis, and pulmonary arterial hypertension, and also highlighted possible connotations for human lung health.

MicroRNAs as Epigenetic Targets of Cigarette Smoke During Embryonic Development

The adverse developmental effects of exposure to Cigarette Smoke (CS) during pregnancy are documented in this paper. These include low birth weight, congenital anomalies, preterm birth, fetal mortality and morbidity. The current biological thought now recognizes that epigenetics represents a fundamental contributing process in embryogenesis, and that the environment can have a profound effect on shaping the epigenome. It has become increasingly recognized that genes encoding microRNAs (miRNAs) might be potential loci for congenital disabilities. One means by which CS can cause developmental anomalies may be through epigenetic mechanisms involving altered miRNA expression. While several studies have focused on genes affected by CS during embryonic/ fetal development, there is a paucity of knowledge on the involvement of miRNAs in this process. This brief review summarizes the current state of knowledge in this area.

Aberrant MicroRNAomics in Pulmonary Complications: Implications in Lung Health and Diseases

Over the last few decades, evolutionarily conserved molecular networks have emerged as important regulators in the expression and function of eukaryotic genomes. Recently, miRNAs (miRNAs), a large family of small, non-coding regulatory RNAs were identified in these networks as regulators of endogenous genes by exerting post-transcriptional gene regulation activity in a broad range of eukaryotic species. Dysregulation of miRNA expression correlates with aberrant gene expression and can play an essential role in human health and disease. In the context of the lung, miRNAs have been implicated in organogenesis programming, such as proliferation, differentiation, and morphogenesis. Gain- or loss-of-function studies revealed their pivotal roles as regulators of disease development, potential therapeutic candidates/targets, and clinical biomarkers. An altered microRNAome has been attributed to several pulmonary diseases, such as asthma, chronic pulmonary obstructive disease, cystic fibrosis, lung cancer, and idiopathic pulmonary fibrosis. Considering the relevant roles and functions of miRNAs under physiological and pathological conditions, they may lead to the invention of new diagnostic and therapeutic tools. This review will focus on recent advances in understanding the role of miRNAs in lung development, lung health, and diseases, while also exploring the progress and prospects of their application as therapeutic leads or as biomarkers.

The role of cigarette smoke-induced epigenetic alterations in inflammation

Background

Exposure to cigarette smoke (CS) is a major threat to human health worldwide. It is well established that smoking increases the risk of respiratory diseases, cardiovascular diseases and different forms of cancer, including lung, liver, and colon. CS-triggered inflammation is considered to play a central role in various pathologies by a mechanism that stimulates the release of pro-inflammatory cytokines. During this process, epigenetic alterations are known to play important roles in the specificity and duration of gene transcription.

Main text

Epigenetic alterations include three major modifications: DNA modifications via methylation; various posttranslational modifications of histones, namely, methylation, acetylation, phosphorylation, and ubiquitination; and non-coding RNA sequences. These modifications work in concert to regulate gene transcription in a heritable fashion. The enzymes that regulate these epigenetic modifications can be activated by smoking, which further mediates the expression of multiple inflammatory genes. In this review, we summarize the current knowledge on the epigenetic alterations triggered by CS and assess how such alterations may affect smoking-mediated inflammatory responses.

Conclusion

The recognition of the molecular mechanisms of the epigenetic changes in abnormal inflammation is expected to contribute to the understanding of the pathophysiology of CS-related diseases such that novel epigenetic therapies may be identified in the near future.

A systematic review of smoking-related epigenetic alterations

The aim of this study is to provide a systematic review of the known epigenetic alterations caused by cigarette smoke; establish an evidence-based perspective of their clinical value for screening, diagnosis, and treatment of smoke-related disorders; and discuss the challenges and ethical concerns associated with epigenetic studies. A well-defined, reproducible search strategy was employed to identify relevant literature (clinical, cellular, and animal-based) between 2000 and 2019 based on AMSTAR guidelines. A total of 80 studies were identified that reported alterations in DNA methylation, histone modifications, and miRNA expression following exposure to cigarette smoke. Changes in DNA methylation were most extensively documented for genes including AHRR, F2RL3, DAPK, and p16 after exposure to cigarette smoke. Likewise, miR16, miR21, miR146, and miR222 were identified to be differentially expressed in smokers and exhibit potential as biomarkers for determining susceptibility to COPD. We also identified 22 studies highlighting the transgenerational effects of maternal and paternal smoking on offspring. This systematic review lists the epigenetic events/alterations known to occur in response to cigarette smoke exposure and identifies the major genes and miRNAs that are potential targets for translational research in associated pathologies. Importantly, the limitations and ethical concerns related to epigenetic studies are also highlighted, as are the effects on the ability to address specific questions associated with exposure to tobacco/cigarette smoke. In the future, improved interpretation of epigenetic signatures will lead to their increased use as biomarkers and/or in drug development.

miRNA‑101‑3p.1 as an independent diagnostic biomarker aggravates chronic obstructive pulmonary disease via activation of the EGFR/PI3K/AKT signaling pathway

Exploring independent biomarkers and delineating pathogenic mechanisms could improve the early diagnosis and treatment of chronic obstructive pulmonary disease (COPD). In the present study, a study was conducted to determine the diagnostic potential of miRNA‑101‑3p.1 in identifying stable COPD (SCOPD) and acute exacerbation of COPD (AECOPD) patients and to reveal the molecular mechanism by which miRNA‑101‑3p.1 regulates COPD progression. miRNA‑101‑3p.1 profiles in peripheral blood mononuclear cells of COPD patients were evaluated. Subsequently, receiver operating characteristic curves were created to demonstrate the diagnostic accuracy of miRNA‑101‑3p.1 in discriminating SCOPD and AECOPD. Finally, the molecular mechanism by which miRNA‑101‑3p.1 regulates COPD progression was explored. The present study revealed that patients with COPD, and especially patients with AECOPD, had significantly increased levels of miRNA‑101‑3p.1 and the level of miRNA‑101‑3p.1 was closely correlated with CAT score and FEV1% predicted. Notably, miRNA‑101‑3p.1 accurately discriminated SCOPD and AECOPD. Furthermore, increasing miRNA‑101‑3p.1 promoted cell proliferation and induced the expression of inflammatory cytokines. Mechanistic investigations revealed that miRNA‑101‑3p.1 inhibited the expression of von Hippel‑Lindau tumor suppressor (pVHL) and ubiquitin conjugating enzyme E2 D1 (UBE2D1). pVHL and UBE2D1 co‑upregulated HIF‑1α, and HIF‑1α mediated activation of the EGFR/PI3K/AKT signaling pathway. The present results collectively demonstrated that miRNA‑101‑3p.1 could act as an independent biomarker for the diagnosis of SCOPD and AECOPD, and that miRNA‑101‑3p.1 facilitates COPD progression by activating the EGFR/PI3K/AKT signaling pathway.

Inferring the Disease-Associated miRNAs Based on Network Representation Learning and Convolutional Neural Networks

Identification of disease-associated miRNAs (disease miRNAs) are critical for understanding etiology and pathogenesis. Most previous methods focus on integrating similarities and associating information contained in heterogeneous miRNA-disease networks. However, these methods establish only shallow prediction models that fail to capture complex relationships among miRNA similarities, disease similarities, and miRNA-disease associations. We propose a prediction method on the basis of network representation learning and convolutional neural networks to predict disease miRNAs, called CNNMDA. CNNMDA deeply integrates the similarity information of miRNAs and diseases, miRNA-disease associations, and representations of miRNAs and diseases in low-dimensional feature space. The new framework based on deep learning was built to learn the original and global representation of a miRNA-disease pair. First, diverse biological premises about miRNAs and diseases were combined to construct the embedding layer in the left part of the framework, from a biological perspective. Second, the various connection edges in the miRNA-disease network, such as similarity and association connections, were dependent on each other. Therefore, it was necessary to learn the low-dimensional representations of the miRNA and disease nodes based on the entire network. The right part of the framework learnt the low-dimensional representation of each miRNA and disease node based on non-negative matrix factorization, and these representations were used to establish the corresponding embedding layer. Finally, the left and right embedding layers went through convolutional modules to deeply learn the complex and non-linear relationships among the similarities and associations between miRNAs and diseases. Experimental results based on cross validation indicated that CNNMDA yields superior performance compared to several state-of-the-art methods. Furthermore, case studies on lung, breast, and pancreatic neoplasms demonstrated the powerful ability of CNNMDA to discover potential disease miRNAs.

miR-145-5p is associated with smoke-related chronic obstructive pulmonary disease via targeting KLF5

Increasing evidence illustrate that dysregulation of microRNAs (miRNAs) is involved in the pathogenesis of chronic obstructive pulmonary disease (COPD), which is mainly resulted from cigarette smoke (CS) exposure. However, the role of miR-145-5p in CS-mediated COPD remains largely unknown. Thus, the aim of this study was to investigate the expression level of miR-145-5p in 31 human lung tissues samples, and to explore its regulatory role in the apoptosis and inflammation of human bronchial epithelial cells (HBECs) following CS extract (CSE) exposure. We found that miR-145-5p was significantly down-regulated in lung tissues from smokers without or with COPD compared to non-smokers. Functional assays showed that miR-145-5p overexpression remarkably alleviated CSE-induced apoptosis and inflammation response by regulating p53-mediated apoptotic signaling and pre-inflammatory factors such as necrosis factor-α (TNF-α), interleukins (IL)-6, IL-8 in HBECs, whereas, down-regulation of miR-145-5p showed opposite effects. Furthermore, luciferase reporter assays verified that Kruppel-like 5 (KLF5) was a direct target of miR-145-5p. Western blot assay also confirmed that KLF5 was up-regulated in COPD tissues and was negatively associated with miR-145-5p expression. Restoration of miR-145-5p expression significantly abrogated the suppressive effect of miR-145-5p on CSE-stimulated apoptosis and inflammation. In addition, the CSE-induced NF-κB signaling activation was suppressed by miR-145-5p overexpression. Therefore, our data suggested that miR-145-5p conferred protection against CSE-induced airway epithelial cell apoptosis and inflammation partially via targeting KLF5, which might be a potential therapeutic biomarker in COPD treatment.

Overexpression Of hsa-miR-664a-3p Is Associated With Cigarette Smoke-Induced Chronic Obstructive Pulmonary Disease Via Targeting FHL1

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is recognized as a chronic lung disease with incomplete reversible airflow limitation, but its pathophysiology was still not clear. This study aimed at investigating regulatory roles of special miRNA-mRNA axis in COPD development.

METHODS

Differentially expressed miRNAs and downstream mRNAs were screened from the Gene Expression Omnibus (GEO) dataset by using the LIMMA package in R software. Weighted Gene Co-expression Network Analysis (WGCNA) was used to construct a co-expression network for COPD. The correlation of dysregulated miRNA(s) and COPD was analyzed, and miRNAs with significant differences were validated in peripheral blood mononuclear cells (PBMCs) from COPD patients by real-time PCR. Regulatory roles of candidate miRNAs and targeted mRNAs were investigated in vitro study.

RESULTS

Thirteen modules of co-expressed miRNAs and mRNAs were constructed from a selected cohort with WGCNA. Turquoise module with 12 differentially expressed miRNAs and 120 mRNAs was significantly correlated with COPD. The expression of hsa-miR-664a-3p, an upregulated miRNA in the module, was increased both in lung tissue and PBMCs from COPD patients, whereas that targeted four and a half LIM domains 1 (FHL1) gene was decreased and positively correlated with forced expiratory volume in 1 sec (FEV1)/forced vital capacity (FVC%) (r = 0.59, p < 0.01). In vitro, luciferase activity assay revealed FHL1 as a target of hsa-miR-664a-3p and it could be directly downregulated by overexpression of hsa-miR-664a-3p. Furthermore, cigarette smoke extract could increase hsa-miR-664a-3p level and decrease FHL1 level in Beas-2B cells.

CONCLUSION

The present study validated significant upregulation of hsa-miR-664a-3p in COPD patients, and its target gene FHL1 was downregulated and positively correlated with FEV1/FVC%; both hsa-miR-664a-3p and FHL1 could be regulated by cigarette smoke extract. Results of bioinformatic analyses and expanded validation suggest that the axis from hsa-miR-664a-3p to FHL1 might play a key role in cigarette smoke-induced COPD, and the exact mechanism should be confirmed in further studies.

The roles of microRNAs in the pathogenesis of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by a progressive and irreversible airflow obstruction, with an abnormal lung function. The etiology of COPD correlates with complex interactions between environmental and genetic determinants. However, the exact pathogenesis of COPD is obscure although it involves multiple aspects including oxidative stress, imbalance between proteolytic and anti-proteolytic activity, immunity and inflammation, apoptosis, and repair and destruction in both airways and lungs. Many genes have been demonstrated to be involved in those pathogenic processes of this disease in patients exposed to harmful environmental factors. Previous reports have investigated promising microRNAs (miRNAs) to disclose the molecular mechanisms for COPD development induced by different environmental exposure and genetic predisposition encounter, and find some potential miRNA biomarkers for early diagnosis and treatment targets of COPD. In this review, we summarized the expression profiles of the reported miRNAs from studies of COPD associated with environmental risk factors including cigarette smoking and air pollution exposures, and provided an overview of roles of those miRNAs in the pathogenesis of the disease. We also highlighted the potential utility and limitations of miRNAs serving as diagnostic biomarkers and therapeutic targets for COPD.

Upregulation of miR-132 contributes to the pathophysiology of COPD via targeting SOCS5

The role of microRNAs has been recently identified in chronic obstructive pulmonary disease (COPD). This study aimed to examine the role of miR-132 in the pathophysiology of COPD and to explore the underlying molecular mechanisms of miR-132 in COPD. MiR-132 and suppressor of cytokine signaling 5 (SOCS5) mRNA expression were detected by qRT-PCR. The number of CD4⁺ and CD8⁺ T cells was analyzed by flow cytometry. SOCS5 and epidermal growth factor receptor (EGFR) protein levels were determined by western blot. Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) concentrations were measured by ELISA. MiR-132 expression was up-regulated in the serum from COPD patients and smokers compared with nonsmoker controls. The number of CD8⁺ T cells was significantly increased in the serum from COPD patients and smokers. MiR-132 expression was negatively correlated with FEV₁/FVC%, and positively correlated with CD8⁺ T cells (%). MiR-132 overexpression repressed SOCS5 expression via directly targeting SOCS5 3'UTR in human monocyte-like cells (THP-1), which was confirmed by luciferase reporter assay. MiR-132 overexpression increased EGFR protein levels and the concentrations of inflammatory cytokines (IL-1β and TNF-α) in THP-1 cells, and these effects were attenuated by enforced expression of SOCS5. Further, cigarette smoke extract (CSE) treatment up-regulated miR-132 expression, down-regulated SOCS5 expression, and increased inflammatory cytokines levels, which was attenuated by miR-132 knockdown in THP-1 cells. Consistent findings were also found in the human bronchial epithelial cells (BEAS-2B). Collectively, our data implicated that miR-132 may promote inflammation in THP-1 and BEAS-2B cells at least via targeting SOCS5 in COPD.

Bioinformatics-based identification of potential microRNA biomarkers in frequent and non-frequent exacerbators of COPD

Objectives

MicroRNAs (miRNAs) play essential roles in the development of COPD. In this study, we aimed to identify and validate potential miRNA biomarkers in frequent and non-frequent exacerbators of COPD patients using bioinformatic analysis.

Materials and methods

The candidate miRNA biomarkers in COPD were screened from Gene Expression Omnibus (GEO) dataset and identified using GEO2R online tool. Then, we performed bioinformatic analyses including target prediction, gene ontology (GO), pathway enrichment analysis and construction of protein–protein interaction (PPI) network. Furthermore, the expression of the identified miRNAs in peripheral blood monocular cells (PBMCs) of COPD patients was validated using quantitative real-time polymerase chain reaction (qRT-PCR).

Results

MiR-23a, miR-25, miR-145 and miR-224 were identified to be significantly downregulated in COPD patients compared with healthy controls. GO analysis showed the four miRNAs involved in apoptotic, cell differentiation, cell proliferation and innate immune response. Pathway analysis showed that the targets of these miRNAs were associated with p53, TGF-β, Wnt, VEGF and MAPK signal pathway. In healthy controls, the miR-25 and miR-224 levels were significantly decreased in smokers compared with nonsmokers (P<0.001 and P<0.05, respectively). In COPD patients, the levels of miR-23a, miR-25, miR-145 and miR-224 were associated with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages. Notably, miR-23a and miR-145 were significantly elevated in non-frequent exacerbators compared with frequent exacerbators (P<0.05), and miR-23a showed higher area under the receiver–operator characteristic curve (AUROC) than miR-145 (0.707 vs 0.665, P<0.05).

Conclusion

MiR-23a, miR-25, miR-145 and miR-224 were associated with the development of COPD, and miR-23a might be a potential biomarker for discriminating the frequent exacerbators from non-frequent exacerbators.

Chronic obstructive pulmonary disease: MicroRNAs and exosomes as new diagnostic and therapeutic biomarkers

Chronic obstructive pulmonary disease (COPD) is known as a progressive lung disease and the fourth leading cause of death worldwide. Despite valuable efforts, there is still no accurate diagnostic and prognostic tool for COPD. Hence, it seems that finding new biomarkers could contribute to provide better therapeutic platforms for COPD patients. Among various biomarkers, microRNAs (miRNAs) have emerged as new biomarkers for the prognosis and diagnosis of patients with COPD. It has been shown that deregulation of miRNAs targeting a variety of cellular and molecular pathways such as Notch, Wnt, hypoxia-inducible factor-1α, transforming growth factor, Kras, and Smad could be involved in COPD pathogenesis. Multiple lines of evidence have indicated that extracellular vesicles such as exosomes could carry a variety of cargos (i.e., mRNAs, miRNAs, and proteins) which transfer various cellular and molecular signals to recipient cells. Here, we summarized various miRNAs which could be applied as diagnostic and prognostic biomarkers in the treatment of patients with COPD. Moreover, we highlighted the role of extracellular vesicles containing miRNAs as diagnostic and prognostic biomarkers in COPD patients.

The potential for targeted rewriting of epigenetic marks in COPD as a new therapeutic approach

Chronic obstructive pulmonary disease (COPD) is an age and smoking related progressive, pulmonary disorder presenting with poorly reversible airflow limitation as a result of chronic bronchitis and emphysema. The prevalence, disease burden for the individual, and mortality of COPD continues to increase, whereas no effective treatment strategies are available. For many years now, a combination of bronchodilators and anti-inflammatory corticosteroids has been most widely used for therapeutic management of patients with persistent COPD. However, this approach has had disappointing results as a large number of COPD patients are corticosteroid resistant. In patients with COPD, there is emerging evidence showing aberrant expression of epigenetic marks such as DNA methylation, histone modifications and microRNAs in blood, sputum and lung tissue. Therefore, novel therapeutic approaches may exist using epigenetic therapy. This review aims to describe and summarize current knowledge of aberrant expression of epigenetic marks in COPD. In addition, tools available for restoration of epigenetic marks are described, as well as delivery mechanisms of epigenetic editors to cells. Targeting epigenetic marks might be a very promising tool for treatment and lung regeneration in COPD in the future.

Role of miR-195 in cigarette smoke-induced chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is regarded as a persistent respiratory symptom, mainly caused by cigarette smoking. Recent data have suggested that some miRNAs are involved in the pathogenesis of COPD. Here, we found that miR-195 was significantly upregulated in the lung tissues of patients with COPD compared to in never smokers. miR-195 expression was also upregulated in cigarette smoke (CS)-exposed mice. Lentivirus-mediated knockdown of miR-195 alleviated CS-induced lung pathological changes and reduced inflammatory cell infiltration as well as production of interleukin-6 and tumor necrosis factor-α in bronchoalveolar lavage fluid. Mechanically, a positive correlation was found between miR-195 and phosphorylation of Akt in lung tissues of COPD patients. PHLPP2 was confirmed as a direct downstream target of miR-195 and negative regulator of miR-195 expression. Inhibition of PHLPP2 enhanced Akt phosphorylation and increased interleukin-6 and tumor necrosis factor-α production in BEAS-2B cells, resembling the effects of miR-195 overexpression. Collectively, our data indicate that miR-195 has a pathogenetic role in CS-induced COPD and regulates Akt signaling by suppressing PHLPP2 expression. miR-195 may be an effective therapeutic target in COPD.

MiR-3202 protects smokers from chronic obstructive pulmonary disease through inhibiting FAIM2: An in vivo and in vitro study

Previous study found the variable miR-3202 as a potential biomarker in smoker with or without chronic obstructive pulmonary disease (COPD). This study aims to identify the molecular involvement of miR-3202 in the pathophysiology of COPD. Level of miR-3202 in blood sample of non-smoker non-COPD(C), smoker without COPD(S), smoker with stable COPD(S-COPD) and smoker with acute exacerbation COPD(AE-COPD) was observed by quantitative real-time PCR. By bioinformatics prediction, Fas apoptotic inhibitory molecule 2 (FAIM2) was identified as a potential target of miR-3202. In vitro, human bronchial epithelial (HBE) cells and cigarette smoke extract (CSE) stimulated T lymphocytes were co-cultured. Cell proliferation and apoptosis of HBE cells were determinated. In vivo, rats were exposed in cigarette smoke for 30 days and expression of miR-3202 and FAIM2 in bronchia were detected. Results showed that The miR-3202 was down-regulated in S, S-COPD and AE-COPD group when compared with C group. Decreased level of miR-3202 was also observed in CSE treated T lymphocyte. Additionally, CSE stimulation increased INF-γ and TNF-α levels and FAIM2 expression whereas inhibited Fas and FasL expressions in T lymphocytes. However, these effects were significantly suppressed by miR-3202 overexpression and enhanced by miR-3202 inhibitor. Likely to exogenous miR-3202, FAIM2 knockdown significantly inhibited HBE cells apoptosis, as well as inhibited INF-γ and TNF-α levels. In COPD rats model, miR-3202 was reduced while FAIM2 was up-regulated accordingly. Here, results suggest that high level miR-3202 in T lymphocytes may protect epithelial cells through targeting FAIM2. MiR-3202 might be used as a notable biomarker of COPD.

MicroRNA-150 protects against cigarette smoke-induced lung inflammation and airway epithelial cell apoptosis through repressing p53: MicroRNA-150 in CS-induced lung inflammation

Cigarette smoke (CS) exposure is an important risk factor for chronic obstructive pulmonary disease (COPD). MicroRNA-150 (miR-150) is involved in several inflammatory diseases. However, little is known about the role of miR-150 in the pathogenesis of COPD. In this study, we established a CS-related mouse model of COPD and evaluated the impact of miR-150 on CS-induced lung inflammation. We further investigated the effects of miR-150 overexpression on pro-inflammatory cytokine production and apoptosis in airway epithelial cells exposed to CS extract (CSE). It was found that miR-150 was significantly ( p < 0.05) downregulated in the lungs of CS-exposed mice, compared to control mice under normal air. The CSE-exposed BEAS-2B airway epithelial cells displayed a four- to six-fold reduction in miR-150 levels, compared to control cells ( p < 0.05). Delivery of miR-150 mimic attenuated CS-induced lung inflammation and accumulation of neutrophils, lymphocytes, and macrophages in bronchoalveolar lavage fluid. Moreover, miR-150 overexpression prevented the induction of interleukin-6, tumor necrosis factor alpha, and interleukin-8 expression and nuclear factor kappa B (NF-κB) transcriptional activity in BEAS-2B cells by CSE. Additionally, miR-150 protected BEAS-2B cells from CSE-induced apoptosis, which was associated with reduced p53 expression. Co-expression of p53 restored apoptotic response to CSE in miR-150-overexpressing BEAS-2B cells. Collectively, miR-150 suppresses CS-induced lung inflammation and airway epithelial cell apoptosis, which is causally linked to repression of p53 expression and NF-κB activity. Restoration of miR-150 expression may represent a potential therapeutic strategy for CS-related COPD.