microRNA-23a contributes to asthma by targeting BCL2 in airway epithelial cells and CXCL12 in fibroblasts

Modulating the m6A Modified Transcription Factor GATA6 Impacts Epithelial Cytokines in Acute Lung Injury

The methylation of m6A (N6-position of adenosine) has been found to be associated with inflammatory response. We hypothesize that m6A modification plays a role in the inflammation of airway epithelial cells during lung inflammation. However, the precise changes and functions of m6A modification in airway epithelial cells in acute lung injury (ALI) are not well understood. Here we report that METTL3 (methyltransferase-like 3)-mediated m6A of GATA6 (GATA-binding factor 6) mRNA inhibits ALI and the secretion of proinflammatory cytokines in airway epithelial cells. The expression of METTL3 and m6A levels decrease in lung tissues of mice with ALI. In cocultures, peripheral blood monocytes secreted TNF-α, which reduces METTL3 and m6A levels in the human bronchial epithelial cell line BEAS-2B. Knockdown of METTL3 promotes IL-6 and TNF-α release in BEAS-2B cells. Conversely, overexpression of METTL3 increases total RNA m6A level and reduces the levels of proinflammatory cytokines TNF-α, transforming growth factor-β, and thymic stromal lymphopoietin. Increasing METTL3 in mouse lungs prevented LPS-induced ALI and reduced the synthesis of proinflammatory cytokines. Mechanistically, sequencing and functional analysis show that METTL3 catalyzes m6A in the 3' untranslated region of GATA6 read by YTH N6-Methyladenosine RNA Binding Protein 2 and triggers mRNA degradation. GATA6 knockdown rescues TNF-α-induced inflammatory cytokine secretion of epithelial cells, indicating that GATA6 is a main substrate of METTL3 in airway epithelial cells. Overall, this study provides evidence of a novel role for METTL3 in the inflammatory cytokine release of epithelial cells and provides an innovative therapeutic target for ALI.

Alarmins and MicroRNAs, a New Axis in the Genesis of Respiratory Diseases: Possible Therapeutic Implications

It is well ascertained that airway inflammation has a key role in the genesis of numerous respiratory pathologies, including asthma, chronic obstructive pulmonary disease, and acute respiratory distress syndrome. Pulmonary tissue inflammation and anti-inflammatory responses implicate an intricate relationship between local and infiltrating immune cells and structural pulmonary cells. Alarmins are endogenic proteins discharged after cell injury in the extracellular microenvironment. The purpose of our review is to highlight the alterations in respiratory diseases involving some alarmins, such as high mobility group box 1 (HMGB1) and interleukin (IL)-33, and their inter-relationships and relationships with genetic non-coding material, such as microRNAs. The role played by these alarmins in some pathophysiological processes confirms the existence of an axis composed of HMGB1 and IL-33. These alarmins have been implicated in ferroptosis, the onset of type 2 inflammation and airway alterations. Moreover, both factors can act on non-coding genetic material capable of modifying respiratory function. Finally, we present an outline of alarmins and RNA-based therapeutics that have been proposed to treat respiratory pathologies.

Molecular Mechanism of YuPingFeng in the Treatment of Asthma Based on Network Pharmacology and Molecular Docking Technology

Objective

To explore the molecular targets and mechanism of YuPingFeng (YPF) for the treatment of asthma by using network pharmacology and molecular docking.

Methods

The potential active ingredients and relevant targets of YPF were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Asthma-related gene targets were retrieved from GeneCards, OMIM, DrugBank, PharmGKB, and TTD databases. The protein-protein (PPI) network between YPF and asthma common targets was constructed by SRING online database and Cytoscape software. GO and KEGG analyses were performed to explore the complicated molecular biological processes and potential pathways. Finally, a molecular docking approach was carried out to verify the results.

Results

We obtained 100 potential targets of the 35 active ingredients in YPF and 1610 asthma-related targets. 60 YPF-asthma common targets were selected to perform PPI analysis. Seven core genes were screened based on two topological calculation methods. GO and KEGG results showed that the main pathways of YPF in treating asthma include TNF signaling pathway and PI3K-Akt signaling pathway. Finally, the molecular docking results indicated that the key ingredients of YPF had a good affinity with the relevant core genes.

Conclusion

This study reflects the multicomponent, multitarget, and multipathway characteristics of YPF in treating asthma, providing a theoretical and scientific basis for the intervention of asthma by traditional Chinese medicine YPF.

miR-3934 regulates the apoptosis and secretion of inflammatory cytokines of basophils via targeting RAGE in asthma

Background

Several miRNAs are now known to have clear connections to the pathogenesis of asthma. The present study focused on the potential role of miR-3934 during asthma development.

Methods

miR-3934 was detected as a down-regulated miRNA in basophils by sequencing analysis. Next, the expression levels of miR-3934 in peripheral blood mononuclear cells of 50 asthma patients and 50 healthy volunteers were examined by RT-qPCR methods. The basophils were then treated with AGEs and transfected with miR-3934 mimics. The apoptosis levels were examined by flow cytometry assay; and the expression levels of cytokines were detected using the ELISA kits. Finally, the Western blot was performed to examined the expression of key molecules in the TGF-β/Smad signaling pathway.

Results

miR-3934 was down-regulated in the basophils of asthmatic patients. The expression of the pro-inflammatory cytokines IL-6, IL-8 and IL-33 was enhanced in basophils from asthmatic patients, and this effect was partially reversed by transfection of miR-3934 mimics. Furthermore, receiver operating characteristics analysis showed that miR-3934 levels can be used to distinguish asthma patients from healthy individuals. miR-3934 partially inhibited advanced glycation end products-induced increases in basophil apoptosis by suppressing expression of RAGE.

Conclusion

Our results indicate that miR-3934 acts to mitigate the pathogenesis of asthma by targeting RAGE and suppressing TGF-β/Smad signaling.

A Mutation in Endogenous saRNA miR-23a Influences Granulosa Cells Response to Oxidative Stress

Phenotypes are the result of the interaction between the gene and the environment, so the response of individuals with different genotypes to an environment is variable. Here, we reported that a mutation in miR-23a influences granulosa cells (GCs) response to oxidative stress, a common mechanism of environmental factors affecting female reproduction. We showed that nuclear miR-23a is a pro-apoptotic miRNA in porcine GCs through the activation of the transcription and function of NORHA, a long non-coding RNA (lncRNA) induces GC apoptosis and responses to oxidative stress. Mechanistically, miR-23a acts as an endogenous small activating RNA (saRNA) to alter histone modifications of the NORHA promoter through the direct binding to its core promoter. A C > T mutation was identified at −398 nt of the miR-23a core promoter, which created a novel binding site for the transcription factor SMAD4 and recruited the transcription repressor SMAD4 to inhibit miR-23a transcription and function in GCs. Notably, g.−398C > T mutation in the miR-23a promoter reduced GCs response to oxidative stress. In addition, g.−398C > T mutation was significantly associated with sow fertility traits. In short, our findings preliminarily revealed the genetic basis of individual differences in the response to oxidative stress from the perspective of a single mutation and identified miR-23a as a candidate gene for the environmental adaptation to oxidative stress.

Sputum microRNA-screening reveals Prostaglandin EP3 receptor as selective target in allergen-specific immunotherapy

BACKGROUND

Several microRNAs (miRs) have been described as potential biomarkers in liquid biopsies and in the context of allergic asthma, while therapeutic effects on the airway expression of miRs remain elusive. In this study, we investigated epigenetic miR-associated mechanisms in the sputum of grass pollen-allergic patients with and without allergen-specific immunotherapy (AIT).

METHODS

Induced sputum samples of healthy controls (HC), AIT-treated and -untreated grass pollen-allergic rhinitis patients with (AA) and without asthma (AR) were profiled using miR microarray and whole-transcriptome microarray analysis of the same samples. miR targets were predicted in silico and used to identify inverse regulation. Local PGE₂  levels were measured using ELISA.

RESULTS

Two hundred and fifty nine miRs were upregulated in the sputum of AA patients compared with HC, while only one was downregulated. The inverse picture was observed in induced sputum of AIT-treated patients: while 21 miRs were downregulated, only 4 miRs were upregulated in asthmatics upon AIT. Of these 4 miRs, miR-3935 stood out, as its predicted target PTGER3, the prostaglandin EP₃ receptor, was downregulated in treated AA patients compared with untreated. The levels of its ligand PGE₂ in the sputum supernatants of these samples were increased in allergic patients, especially asthmatics, and downregulated after AIT. Finally, local PGE₂  levels correlated with ILC2 frequencies, secreted sputum IL-13 levels, inflammatory cell load, sputum eosinophils and symptom burden.

CONCLUSIONS

While profiling the sputum of allergic patients for novel miR expression patterns, we uncovered an association between miR-3935 and its predicted target gene, the prostaglandin E₃ receptor, which might mediate AIT effects through suppression of the PGE₂ -PTGER3 axis.

Mechanisms of allergy and adult asthma

PURPOSE OF REVIEW

Allergic asthma reflects the interplay between inflammatory mediators and immune, airway epithelial, and other cells. This review summarizes key insights in these areas over the past year.

RECENT FINDINGS

Key findings over the past year demonstrate that epithelial cells mediate tight junction breakdown to facilitate the development of asthma-like disease in mice. Innate lymph lymphoid cells (ILC), while previously shown to promote allergic airway disease, have now been shown to inhibit the development of severe allergic disease in mice. Fibrinogen cleavage products (previously shown to mediate allergic airway disease and macrophage fungistatic immunity by signaling through Toll-like receptor 4) have now been shown to first bind to the integrin Mac-1 (CD11c/CD18). Therapeutically, recent discoveries include the development of the antiasthma drug PM-43I that inhibits the allergy-related transcription factors STAT5 and STAT6 in mice, and confirmatory evidence of the efficacy of the antifungal agent voriconazole in human asthma.

SUMMARY

Studies over the past year provide critical new insight into the mechanisms by which epithelial cells, ILC, and coagulation factors contribute to the expression of asthma-like disease and further support the development antiasthma drugs that block STAT factors and inhibit fungal growth in the airways.

MiR-140-3p Impedes Gastric Cancer Progression and Metastasis by Regulating BCL2/BECN1-Mediated Autophagy

Introduction

MiRNAs have been proven to modulate the progression of gastric cancer (GC). In this field, we evaluated the role and mechanism of miR-140-3p in GC.

Methods

Western blotting and qRT-PCR were used to detect the levels of miR-140-3p and BCL2. The interaction of miR-140-3p and BCL2 was confirmed by dual-luciferase reporter and miRNA pull-down assays. CCK-8, EdU, wound healing, and Transwell invasion assays were performed to evaluate cell proliferation, migration and invasion. Autophagy was analyzed using Western blot analysis of the LC3-II/I ratio and immunofluorescence staining. A xenograft model was established to reveal the role of miR-140-3p in tumorigenesis.

Results

In GC cell lines and tissues, miR-140-3p was highly expressed, and BCL2 was expressed at low levels. MiR-140-3p directly inhibited BCL2 expression and indirectly promoted BECN1 expression, and BCL2 inhibited BECN1 expression. MiR-140-3p overexpression or silencing restrained or facilitated migration, invasion and EMT in GC cells. Moreover, we noticed that overexpression or downregulation of miR-140-3p promoted or suppressed BECN1-dependent autophagy in GC cells. BCL2 introduction or BECN1 silencing in GC cells partially blocked the effects of miR-140-3p. In conclusion, miR-140-3p directly downregulated the expression of BCL2, BCL2 downregulation further activated BECN1-dependent autophagy, and autophagy activation further inhibited EMT.

Conclusion

miR-140-3p may act as a tumor suppressor by targeting BCL2 and regulating downstream BECN1-induced autophagy and metastasis in GC progression.

MicroRNA Targets for Asthma Therapy

Asthma is a chronic inflammatory obstructive lung disease that is stratified into endotypes. Th2 high asthma is due to an imbalance of Th1/Th2 signaling leading to abnormally high levels of Th2 cytokines, IL-4, IL-5, and IL-13 and in some cases a reduction in type I interferons. Some asthmatics express Th2 low, Th1/Th17 high phenotypes with or without eosinophilia. Most asthmatics with Th2 high phenotype respond to beta-adrenergic agonists, muscarinic antagonists, and inhaled corticosteroids. However, 5-10% of asthmatics are not well controlled by these therapies despite significant advances in lung immunology and the pathogenesis of severe asthma. This problem is being addressed by developing novel classes of anti-inflammatory agents. Numerous studies have established efficacy of targeting pro-inflammatory microRNAs in mouse models of mild/moderate and severe asthma. Current approaches employ microRNA mimics and antagonists designed for use in vivo. Chemically modified oligonucleotides have enhanced stability in blood, increased cell permeability, and optimized target specificity. Delivery to lung tissue limits clinical applications, but it is a tractable problem. Future studies need to define the most effective microRNA targets and effective delivery systems. Successful oligonucleotide drug candidates must have adequate lung cell uptake, high target specificity, and efficacy with tolerable off-target effects.

RUNX2 promotes vascular injury repair by activating miR-23a and inhibiting TGFBR2

Background

Previous evidence has suggested that the transcription factor, runt-related transcription factor 2 (RUNX2), promotes the repair of vascular injury and activates the expression of microRNA-23a (miR-23a). TGF-β receptor type II (TGFBR2) has been found to mediate smooth muscle cells (SMCs) following arterial injury. However, the interactions among RUNX2, miR-23a and TGFBR2 in vascular injury have not been investigated thoroughly yet. Therefore, we aim to explore the mechanism of how RUNX2 triggers the expression of miR-23a and its effects on the repair of vascular injury.

Methods

C57BL/6 mice were used to produce a model of arterial injury in vivo. Mouse arterial SMCs were isolated for in vitro cell injury induction by 100 nmol/L tumor necrosis factor-α (TNF-α). Gain-and loss-of-function studies were conducted to assess cell viability and apoptosis by using cell counting kit (CCK)-8 assay and flow cytometry respectively. The levels of TNF-α, interleukin-6 (IL-6), and monocyte chemotactic protein-1 (MCP-1) were examined by enzyme-linked immunosorbent assay (ELISA). The interaction between RUNX2 and miR-23a was identified by chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays, while the targeting relationship between miR-23a and TGFBR2 was analyzed by RNA immunoprecipitation (RIP) and dual luciferase reporter assays.

Results

Both RUNX2 and miR-23a exhibited low levels of expressions, while TGFBR2 had a high level of expression in mice with induced arterial injury. RUNX2 was found to bind to the promoter of miR-23a and activate miR-23a, while miR-23a targeted TGFBR2. Ectopic RUNX2 expression inhibited inflammatory cell infiltration, and promoted collagen content by upregulating miR-23a and downregulating TGFBR2. Furthermore, the overexpression of RUNX2 increased viability and decreased apoptosis in vascular smooth muscle cells (VSMCs) by activating miR-23a.

Conclusions

The overexpression of RUNX2 elevated the expression of miR-23, thus inhibiting TGFBR2 and promoting vascular injury repair.

Borneol inhibits CD4 + T cells proliferation by down-regulating miR-26a and miR-142-3p to attenuate asthma

BACKGROUND

Asthma is a chronic airway inflammatory disease caused by a variety of cytokines and signaling pathways closely related to immunoregulation. Corticosteroids are the most widely used drug in the asthma treatment. However, the use of corticosteroids could cause topical side effects. So, it's important to find new drugs for asthma treatment. Our study aims to explore the pharmacological effect of borneol on asthma and its underlying mechanism.

METHODS

We constructed the OVA-induced asthma model to investigate the effect of borneol on asthma in mice. HE and PAS staining was used to detect the effect of borneol on pathological change of mice with asthma. Inflammatory cytokines were measured by ELISA. qRT-PCR was used to explore the effect of borneol on microRNAs expression. Cell proliferation of CD4 + T cells was detected by CCK-8 assay and flow cytometry. Western blot was used to detect pten expression and Akt activation.

RESULTS

We found that borneol significantly alleviated asthma progression in mice. Borneol inhibited CD4 + T cells infiltration in vivo and proliferation in vitro by downregulating miR-26a and miR-142-3p. miR-26a and miR-142-3p promoted CD4 + T cells proliferation in vitro through targeting Pten. Overexpression of miR-26a and miR-142-3p abolished the effect of borneol in vivo.

CONCLUSION

In a word, these findings suggested that borneol attenuated asthma in mice by decreasing the CD4 + T cells infiltration. The molecular mechanism of borneol was dependent on the downregulation of miR-26a and miR-142-3p to upregulate the Pten expression.

MiR-135b Alleviates Airway Inflammation in Asthmatic Children and Experimental Mice with Asthma via Regulating CXCL12

OBJECTIVE

To clarify the possible influence of miR-135b on CXCL12 and airway inflammation in children and experimental mice with asthma.

METHODS

The expressions of miR-135b and CXCL12 were detected using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) in the serum of asthmatic children. Besides, the experimental asthmatic mice were established by aerosol inhalation of ovalbumin (OVA) followed by the treatment with agomiR-135b and antagomir-135b. Pathological changes of lung tissues were observed via HE staining and PAS staining. Besides, the airway hyperresponsiveness of mice was elevated and bronchoalveolar lavage fluid (BALF) was isolated for cell categorization and counting. The inflammatory cytokines in BALF were determined by enzyme-linked immunosorbent assay (ELISA), and the infiltration of Th17 cells in lung tissues was measured using flow cytometry.

RESULTS

MiR-135b was downregulated and CXCL12 was upregulated in asthmatic children and mice. Overexpression of miR-135b may down-regulate CXCL12 expression in the lung of OVA mice, resulting in significant decreases in inflammatory infiltration, hyperplasia of goblet cell, airway hyperresponsiveness, cell quantity, as well as the quantity of eosinophilic granulocytes, neutrophils and lymphocytes in BALF. Also, the levels of inflammatory cytokines (IL-4, IL-5, IL-13 and IL-17) and the ratio of Th17 cells and IL-17 levels in lung tissues were decreased. However, miR-135b downregulation reversed these changes in OVA mice.

CONCLUSION

MiR-135b may inhibit immune responses of Th17 cells to alleviate airway inflammation and hyperresponsiveness in asthma possibly by targeting CXCL12, showing the potential value in asthma treatment.

Upregulating microRNA-874-3p inhibits CXCL12 expression to promote angiogenesis and suppress inflammatory response in ischemic stroke

Identification of specific biomarkers for ischemic stroke is necessary due to their abilities to improve treatment outcomes. Many studies have demonstrated the involvement of microRNAs (miRNAs) in the pathogenesis and complications of ischemic stroke and patient outcomes. We found that the expression of miR-874-3p was downregulated in clinical samples of ischemic stroke. Thus the present study explored the potential role of miR-874-3p in ischemic stroke and related mechanisms. A mouse model of ischemic stroke was constructed by middle cerebral artery occlusion. The relationship among miR-874-3p, C-X-C motif chemokine ligand 12 (CXCL12), and the Wnt/β-catenin pathway was explored by dual luciferase reporter assay and Western blot analysis. Angiogenesis and brain tissue apoptosis were evaluated by immunofluorescence staining and TUNEL staining, respectively. ELISA was introduced to measure levels of inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin (IL)-1, IL-6, IL-8, and IL-10 in brain tissues. Primary hippocampal neuronal cells were isolated from the mouse model of ischemic stroke and incubated with human umbilical vein endothelial cells (HUVECs) for HUVEC tube formation. High expression of CXCL12 and low expression of miR-874-3p were confirmed in ischemic stroke. In addition, miR-874-3p was found to target and downregulate CXCL12, thus reducing TNF-α, IL-1, IL-6, and IL-8 levels, but enhancing IL-10 level. Collectively, upregulating miR-874-3p inhibits CXCL12 expression to promote angiogenesis and inhibit inflammation in ischemic stroke mice by activating the Wnt/β-catenin pathway, which may provide a new direction of ischemic stroke treatment.

Siglec1 enhances inflammation through miR-1260-dependent degradation of IκBα in COPD

It has been documented that sialic acid-binding Ig-like lectin 1 (Siglec1) is a cell surface protein with a variety of functions in the immune system. In the present study, we evaluated whether Siglec1 plays a role in chronic obstructive pulmonary disease (COPD). Results show that the expression of Siglec1 was increased in the lung of COPD rats, and that Siglec1 overexpression greatly enhanced the expression of inflammatory cytokines including tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and IL-6 in cigarette smoke extract (CSE)-treated NR8383 cells, a rat lung-derived macrophage cell line. Notably, the proinflammatory effect of Siglec1 was totally inhibited by overexpression of nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor α (IκBα). Importantly, Siglec1 overexpression increased miR-1260, which then degraded IκBα through its 3' untranslated region (3'UTR). Further study demonstrated that miR-1260 inhibitor attenuated inflammation in CSE-induced rat COPD lung and in CSE-treated NR8383 cells. Finally, the inhibitory effect of miR-1260 on inflammation was totally lost when IκBα was inhibited. In summary, the present study demonstrated that Siglec1 exerts its proinflammatory effects through increasing miR-1260, leading to decreased expression of IκBα.

LncRNA MEG3 inhibits cell proliferation and induces apoptosis in laryngeal cancer via miR-23a/APAF-1 axis

Long non‐coding RNA (LncRNA) MEG3 serves a regulatory role in the progression of several types of cancer, but the role of MEG3 in laryngeal cancer is still unknown. The aim of this study was to explore the regulatory role and mechanism of MEG3 in laryngeal cancer. MEG3 expression in 50 laryngeal cancer tissue samples was detected by reverse transcription‐quantitative polymerase chain reaction (RT‐qPCR). The effects of MEG3 overexpression on laryngeal cancer cells were investigated in vitro and in vivo. The mechanism of competitive endogenous RNA (ceRNA) was validated through luciferase reporter assay, RT‐qPCR and Western blotting. MEG3 was down‐regulated in laryngeal cancer tissues, and the low MEG3 expression was associated with advanced clinical stage. Additionally, MEG3 overexpression inhibited the proliferation and induced the apoptosis of laryngeal cancer cells in vitro and in vivo. Particularly, MEG3 bound to miR‐23a specifically and a reciprocal negative regulation existed between miR‐23a and MEG3. Moreover, MEG3 up‐regulated apoptotic protease activating factor‐1 (APAF‐1), a known miR‐23a's target, thereby leading to the activation of caspase‐9 and caspase‐3. Meanwhile, these activated effects were rescued by miR‐23a overexpression. In conclusion, the present study demonstrated that MEG3 functions as a novel tumour suppressive LncRNA in laryngeal cancer for the first time. Furthermore, MEG3 may act as a ceRNA to regulate APAF‐1 expression by competitive binding to miR‐23a, thereby regulating the progression of laryngeal cancer.