MicroRNAs as Therapeutic Targets in Lung Disease: Prospects and Challenges

Upregulated microRNA-125b-5p in patients with asthma-COPD overlap mediates oxidative stress and late apoptosis via targeting IL6R/TRIAP1 signaling

BACKGROUND

Among patients with chronic obstructive pulmonary disease (COPD), some have features of both asthma and COPD-a condition categorized as asthma-COPD overlap (ACO). Our aim was to determine whether asthma- or COPD-related microRNAs (miRNAs) play a role in the pathogenesis of ACO.

METHODS

A total of 22 healthy subjects and 27 patients with ACO were enrolled. We selected 6 miRNAs that were found to correlate with COPD and asthma. The expression of miRNAs and target genes was analyzed using quantitative reverse-transcriptase polymerase chain reaction. Cell apoptosis and intracellular reactive oxygen species production were evaluated using flow cytometry. In vitro human monocytic THP-1 cells and primary normal human bronchial epithelial (NHBE) cells under stimuli with cigarette smoke extract (CSE) or ovalbumin (OVA) allergen or both were used to verify the clinical findings.

RESULTS

We identified the upregulation of miR-125b-5p in patients with ACO and in THP-1 cells stimulated with CSE plus OVA allergen. We selected 16 genes related to the miR-125b-5p pathway and found that IL6R and TRIAP1 were both downregulated in patients with ACO and in THP-1 cells stimulated with CSE plus OVA. The percentage of late apoptotic cells increased in the THP-1 cell culture model when stimulated with CSE plus OVA, and the effect was reversed by transfection with miR-125b-5p small interfering RNA (siRNA). The percentage of reactive oxygen species-producing cells increased in the NHBE cell culture model when stimulated with CSE plus OVA, and the effect was reversed by transfection with miR-125b-5p siRNA. In NHBE cells, siRNA transfection reversed the upregulation of STAT3 under CSE+OVA stimulation.

CONCLUSIONS

Our study revealed that upregulation of miR-125b-5p in patients with ACO mediated late apoptosis in THP-1 cells and oxidative stress in NHBE cells via targeting IL6R and TRIAP1. STAT3 expression was also regulated by miR-125b-5p.

miR-146a regulates emphysema formation and abnormal inflammation in the lungs of two mouse models

miR-146a, a microRNA (miRNA) that regulates inflammatory responses, plays an important role in many inflammatory diseases. Although an in vitro study had suggested that miR-146a is involved in abnormal inflammatory response, being a critical factor in the pathogenesis of chronic obstructive pulmonary disease (COPD), in vivo evidence of its pathogenic role in COPD remains limited. Eight-week-old male B6(FVB)-Mir146tm1.1Bal/J [miR-146a knockout (KO)] and C57BL/6J mice were intratracheally administered elastase and evaluated after 28 days or exposed to cigarette smoke (CS) and evaluated after 5 mo. miR-146a expression was significantly increased in C57BL/6J mouse lungs due to elastase administration (P = 0.027) or CS exposure (P = 0.019) compared with that in the control group. Compared with C57BL/6J mice, elastase-administered miR-146a-KO mice had lower average computed tomography (CT) values (P = 0.017) and increased lung volume-to-weight ratio (P = 0.016), mean linear intercept (P < 0.001), and destructive index (P < 0.001). Moreover, total cell (P = 0.006), macrophage (P = 0.001), neutrophil (P = 0.026), chemokine (C-X-C motif) ligand 2/macrophage inflammatory protein-2 [P = 0.045; in bronchoalveolar lavage fluid (BALF)], cyclooxygenase-2, and matrix metalloproteinase-2 levels were all increased (in the lungs). Following long-term CS exposure, miR-146a-KO mice showed a greater degree of emphysema formation in their lungs and inflammatory response in the BALF and lungs than C57BL/6J mice. Collectively, miR-146a protected against emphysema formation and the associated abnormal inflammatory response in two murine models.NEW & NOTEWORTHY This study demonstrates that miR-146a expression is upregulated in mouse lungs because of elastase- and CS-induced emphysema and that the inflammatory response by elastase or CS is enhanced in the lungs of miR-146a-KO mice than in those of control mice, resulting in the promotion of emphysema. This is the first study to evaluate the protective role of miR-146a in emphysema formation and the associated abnormal inflammatory response in different in vivo models.

Cytokine storm in the pathophysiology of COVID-19: Possible functional disturbances of miRNAs

SARS-CoV-2, as the causative agent of COVID-19, is an enveloped positives-sense single-stranded RNA virus that belongs to the Beta-CoVs sub-family. A sophisticated hyper-inflammatory reaction named cytokine storm is occurred in patients with severe/critical COVID-19, following an imbalance in immune-inflammatory processes and inhibition of antiviral responses by SARS-CoV-2, which leads to pulmonary failure, ARDS, and death. The miRNAs are small non-coding RNAs with an average length of 22 nucleotides which play various roles as one of the main modulators of genes expression and maintenance of immune system homeostasis. Recent evidence has shown that Homo sapiens (hsa)-miRNAs have the potential to work in three pivotal areas including targeting the virus genome, regulating the inflammatory signaling pathways, and reinforcing the production/signaling of IFNs-I. However, it seems that several SARS-CoV-2-induced interfering agents such as viral (v)-miRNAs, cytokine content, competing endogenous RNAs (ceRNAs), etc. preclude efficient function of hsa-miRNAs in severe/critical COVID-19. This subsequently leads to increased virus replication, intense inflammatory processes, and secondary complications development. In this review article, we provide an overview of hsa-miRNAs roles in viral genome targeting, inflammatory pathways modulation, and IFNs responses amplification in severe/critical COVID-19 accompanied by probable interventional factors and their function. Identification and monitoring of these interventional elements can help us in designing the miRNAs-based therapy for the reduction of complications/mortality rate in patients with severe/critical forms of the disease.

Identification of common microRNA between COPD and non-small cell lung cancer through pathway enrichment analysis

BACKGROUND

Different factors have been introduced which influence the pathogenesis of chronic obstructive pulmonary disease (COPD) and non-small cell lung cancer (NSCLC). COPD as an independent factor is involved in the development of lung cancer. Moreover, there are certain resemblances between NSCLC and COPD, such as growth factors, activation of intracellular pathways, as well as epigenetic factors. One of the best approaches to understand the possible shared pathogenesis routes between COPD and NSCLC is to study the biological pathways that are activated. MicroRNAs (miRNAs) are critical biomolecules that implicate the regulation of several biological and cellular processes. As such, the main goal of this study was to use a systems biology approach to discover common dysregulated miRNAs between COPD and NSCLC, one that targets most genes within common enriched pathways.

RESULTS

To reconstruct the miRNA-pathways for each disease, we used the microarray miRNA expression data. Then, we employed "miRNA set enrichment analysis" (MiRSEA) to identify the most significant joint miRNAs between COPD and NSCLC based on the enrichment scores. Overall, our study revealed the involvement of the targets of miRNAs (such as has-miR-15b, hsa-miR-106a, has-miR-17, has-miR-103, and has-miR-107) in the most important common biological pathways.

CONCLUSIONS

According to the promising results of the pathway analysis, the identified miRNAs can be utilized as the new potential signatures for therapy through understanding the molecular mechanisms of both diseases.

The Plasma Levels of hsa-miR-19b-3p, hsa-miR-125b-5p and hsa-miR-320c in Patients with Asthma, COPD and Asthma-COPD Overlap Syndrome (ACOS)

BACKGROUND

Bronchial Asthma (BA) and Chronic Obstructive Pulmonary Disease (COPD) are chronic airway inflammation diseases. In recent years, patients with signs of both BA and COPD have been assigned to a separate group as Asthma-COPD Overlap Syndrome (ACOS). Free-circulating plasma microRNAs are considered as potential biomarkers of pulmonary diseases, including BA, COPD and ACOS.

OBJECTIVE

This study aimed to investigate the expression level of free-circulating plasma microRNAs hsa-miR-19b-3p, hsa-miR-125b-5p and hsa-miR-320c in patients with BA, COPD and ACOS for the detection and validation of new microRNAs as biomarkers for chronic lung diseases.

METHODS

The relative expression levels of 720 microRNAs were evaluated by Real Time-Polymerase Chain Reaction (RT-PCR) in patients with COPD and BA. Three upregulated microRNAs (hsa-miR-19b-3p, hsa-miR-125b-5p and hsa-miR-320c) were selected for further study. The obtained data was analyzed using the microRNA PCR Array Data Analysis tool. The sensitivity and specificity were estimated using the area under the Receiver Operating Characteristics curve (ROC).

RESULTS

The expression level of free-circulating hsa-miR-19b-3p was decreased in the blood plasma of patients with BA and ACOS, and increased in patients with COPD. hsa-miR-125b-5p was downregulated in the blood plasma of patients with COPD, and upregulated in patients with BA and ACOS. hsa-miR-320c was downregulated in the blood plasma of patients with BA, and upregulated in patients with COPD and ACOS. The ROC curves of patients with BA for hsa-miR-19b-3p, patients with ACOS for hsa-miR-125b-5p and patients with COPD for hsa-miR-320c revealed the probability of them as valuable biomarkers with AUCs of 0.824, 0.825, and 0.855, respectively.

CONCLUSION

Our study revealed three promising biomarkers for the diagnosis of COPD, BA and ACOS.

miR-4456/CCL3/CCR5 Pathway in the Pathogenesis of Tight Junction Impairment in Chronic Obstructive Pulmonary Disease

Background: Cigarette smoke exposure (CSE) is a major cause of chronic obstructive pulmonary disease (COPD). The smoke disrupts cell-cell adhesion by inducing epithelial barrier damage to the tight junction (TJ) proteins. Even though the inflammatory mechanism of chemokine (C-C motif) ligand 3 (CCL3) in COPD has gained increasing attention in the research community, however, the underlying signaling pathway, remains unknown.

Objectives: To identify the relationship of CCL3 in the pathogenesis of tight junction impairment in COPD and the pathway through which CSE causes damage to TJ in COPD via CCL3, both in vivo and in vitro.

Methods: We screened the inflammatory factors in the peripheral blood mononuclear cells (PBMCs) from healthy controls and patients at each GOLD 1-4 stage of chronic obstructive pulmonary disease. RT-PCR, western blot, and ELISA were used to detect the levels of CCL3, ZO-1, and occludin after Cigarette smoke exposure. Immunofluorescence was applied to examine the impairment of the TJs in 16-HBE and A549 cells. The reverse assay was used to detect the effect of a CCR5 antagonist (DAPTA) in COPD. In the CSE-induced COPD mouse model, H&E staining and lung function tests were used to evaluate the pathological and physical states in each group. Immunofluorescence was used to assess the impairment of TJs in each group. ELISA and RT-PCR were used to examine the mRNA or protein expression of CCL3 or miR-4456 in each group.

Results: The in vivo and in vitro results showed that CCL3 expression was increased in COPD compared with healthy controls. CCL3 caused significant injury to TJs through its C-C chemokine receptor type 5 (CCR5), while miR-4456 could suppress the effect of CCL3 on TJs by binding to the 3′-UTR of CCL3.

Conclusion: miR-4456/CCL3/CCR5 pathway may be a potential target pathway for the treatment of COPD.

Cell-free nucleic acid patterns in disease prediction and monitoring-hype or hope?

Interest in the use of cell-free nucleic acids (CFNAs) as clinical non-invasive biomarker panels for prediction and prevention of multiple diseases has greatly increased over the last decade. Indeed, circulating CFNAs are attributable to many physiological and pathological processes such as imbalanced stress conditions, physical activities, extensive apoptosis of different origin, systemic hypoxic-ischemic events and tumour progression, amongst others. This article highlights the involvement of circulating CFNAs in local and systemic processes dealing with the question, whether specific patterns of CFNAs in blood, their detection, quantity and quality (such as their methylation status) might be instrumental to predict a disease development/progression and could be further utilised for accompanying diagnostics, targeted prevention, creation of individualised therapy algorithms, therapy monitoring and prognosis. Presented considerations conform with principles of 3P medicine and serve for improving individual outcomes and cost efficacy of medical services provided to the population.

Protective Effect of Trans-chalcone Against High-Fat Diet-Induced Pulmonary Inflammation Is Associated with Changes in miR-146a And pro-Inflammatory Cytokines Expression in Male Rats

High-fat diet (HFD) increases the risk of non-communicable inflammatory diseases including pulmonary disorders. Trans-chalcone is a chalcone with antioxidant and anti-inflammatory effects. This study aimed to explore the effect of this natural compound and molecular mechanism of its effect on HFD-induced pulmonary inflammation. Twenty-eight male Wistar rats were randomly divided into four main groups (n = 7 per each group): control, receiving 10% tween 80; Chal, receiving trans-chalcone, HFD, receiving a high-fat emulsion and 10% tween 80; HFD + Chal, receiving a high-fat emulsion and trans-chalcone. After 6 weeks, the lungs were dissected, and the expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and miR-146a were determined using real-time PCR. Moreover, histological analysis was done by hematoxylin and eosin staining. Significant elevations in TNF-α, IL-1β, IL-6, and miR-146a expression levels (P < 0.001) were observed within the lungs of HFD-fed rats compared with the control. However, oral administration of trans-chalcone reduced TNF-α, IL-1β, IL-6 (P < 0.001), and miR-146a (P < 0.05) expression levels and also improved HFD-induced histological abnormalities. These findings indicate that trans-chalcone ameliorates lung inflammatory response and structural alterations. It seems that this beneficial effect is associated with the down-regulation of pro-inflammatory cytokines and miR-146a.

Deducting MicroRNA-Mediated Changes Common in Bronchial Epithelial Cells of Asthma and Chronic Obstructive Pulmonary Disease-A Next-Generation Sequencing-Guided Bioinformatic Approach

Asthma and chronic obstructive pulmonary disease (COPD) are chronic airway inflammatory diseases that share some common features, although these diseases are somewhat different in etiologies, clinical features, and treatment policies. The aim of this study is to investigate the common microRNA-mediated changes in bronchial epithelial cells of asthma and COPD. The microRNA profiles in primary bronchial epithelial cells from asthma (AHBE) and COPD (CHBE) patients and healthy subjects (NHBE) were analyzed with next-generation sequencing (NGS) and the significant microRNA changes common in AHBE and CHBE were extracted. The upregulation of hsa-miR-10a-5p and hsa-miR-146a-5p in both AHBE and CHBE was confirmed with quantitative polymerase chain reaction (qPCR). Using bioinformatic methods, we further identified putative targets of these microRNAs, which were downregulated in both AHBE and CHBE: miR-10a-5p might suppress BCL2, FGFR3, FOXO3, PDE4A, PDE4C, and PDE7A; miR-146a-5p might suppress BCL2, INSR, PDE4D, PDE7A, PDE7B, and PDE11A. We further validated significantly decreased expression levels of FOXO3 and PDE7A in AHBE and CHBE than in NHBE with qPCR. Increased serum miR-146a-5p level was also noted in patients with asthma and COPD as compared with normal control subjects. In summary, our study revealed possible mechanisms mediated by miR-10a-5p and miR-146a-5p in the pathogenesis of both asthma and COPD. The findings might provide a scientific basis for developing novel diagnostic and therapeutic strategies.

Interferon-Mediated Response to Human Metapneumovirus Infection

Human metapneumovirus (HMPV) is one of the leading causes of respiratory diseases in infants and children worldwide. Although this pathogen infects mainly young children, elderly and immunocompromised people can be also seriously affected. To date, there is no commercial vaccine available against it. Upon HMPV infection, the host innate arm of defense produces interferons (IFNs), which are critical for limiting HMPV replication. In this review, we offer an updated landscape of the HMPV mediated-IFN response in different models as well as some of the defense tactics employed by the virus to circumvent IFN response.

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.