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

Harnessing the power of miRNAs: The molecular architects of asthma pathogenesis and potential targets for therapeutic innovation

Asthma is a chronic non-communicable respiratory disease that is characterized by airway inflammation and hyperreactivity. Defective functions of airway smooth muscle and dysregulated signaling pathways play a crucial role in the pathogenesis of asthma. Anti-inflammatories and targeted therapy are mainly used for the treatment of asthma. Recent studies have investigated the role of non-coding RNAs, especially microRNAs (miRNAs; miR) in regulating gene expression and their involvement in the dysfunctional signaling pathways. In immune-mediated diseases, including asthma, miRNAs govern the actions of cells that form the airway structure and those responsible for the defense mechanisms in the bronchi and lungs. miRNAs control cell survival, proliferation, and growth, as well as the cells' capacity to produce and release chemokines and immune mediators. Moreover, miRNAs have an important role in the response to therapeutic interventions. Collectively, this review highlights the regulatory roles of miRNAs in modulating the different signaling pathways and therapeutic responses in asthma. Patients who suffer from asthma, particularly those with severe disease characteristics, may benefit from the prospective treatment options that include targeting miRNAs in order to reduce airway inflammation, hyperreactivity, and mucus production.

miRNAs as Modern Biomarkers in Asthma Therapy

Asthma is a chronic inflammatory disease of the airways characterized by shortness of breath, chest tightness, coughing, and wheezing. For several decades (approximately 30 years), miRNAs and their role in asthma have been of constant interest among scientists. These small, non-coding RNA fragments, 18-25 nucleotides long, regulate gene expression at the post-transcriptional level by binding to the target mRNA. In this way, they affect several biological processes, e.g., shaping airway structures, producing cytokines and immune mediators, and controlling defense mechanisms. Publications confirm their potential role in the diagnosis and monitoring of the disease, but only some articles address the use of miRNAs in the treatment of asthma. The following paper reviews the latest available studies and presents miRNAs as a useful tool for predicting the effectiveness of the included treatment, early diagnosis of exacerbations, and in assessing patient compliance for different groups of drugs used in asthma. The latest known pathways underlying the pathogenesis of the disease, which are associated with a change in miRNA expression, may be precise targets of therapeutic activity in the future.

Co-Expression Analysis of Airway Epithelial Transcriptome in Asthma Patients with Eosinophilic vs. Non-Eosinophilic Airway Infiltration

Asthma heterogeneity complicates the search for targeted treatment against airway inflammation and remodeling. We sought to investigate relations between eosinophilic inflammation, a phenotypic feature frequent in severe asthma, bronchial epithelial transcriptome, and functional and structural measures of airway remodeling. We compared epithelial gene expression, spirometry, airway cross-sectional geometry (computed tomography), reticular basement membrane thickness (histology), and blood and bronchoalveolar lavage (BAL) cytokines of n = 40 moderate to severe eosinophilic (EA) and non-eosinophilic asthma (NEA) patients distinguished by BAL eosinophilia. EA patients showed a similar extent of airway remodeling as NEA but had an increased expression of genes involved in the immune response and inflammation (e.g., KIR3DS1), reactive oxygen species generation (GYS2, ATPIF1), cell activation and proliferation (ANK3), cargo transporting (RAB4B, CPLX2), and tissue remodeling (FBLN1, SOX14, GSN), and a lower expression of genes involved in epithelial integrity (e.g., GJB1) and histone acetylation (SIN3A). Genes co-expressed in EA were involved in antiviral responses (e.g., ATP1B1), cell migration (EPS8L1, STOML3), cell adhesion (RAPH1), epithelial-mesenchymal transition (ASB3), and airway hyperreactivity and remodeling (FBN3, RECK), and several were linked to asthma in genome- (e.g., MRPL14, ASB3) or epigenome-wide association studies (CLC, GPI, SSCRB4, STRN4). Signaling pathways inferred from the co-expression pattern were associated with airway remodeling (e.g., TGF-β/Smad2/3, E2F/Rb, and Wnt/β-catenin).

Long non-coding RNA MALAT1 promotes Th2 differentiation by regulating microRNA-135b-5p/GATA-3 axis in children with allergic rhinitis

Allergic rhinitis (AR) threatens patient survival. CD4⁺ T cells play key roles in AR progression. Long non-coding RNAs (lncRNAs) are key regulators of cell differentiation. Therefore, we investigated the molecular mechanism of the lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in AR. Expression levels of MALAT1, microRNA (miR)-135b-5p, interleukin-4 (IL-4), and GATA-binding protein 3 (GATA-3) in the nasal mucosa of AR patients were quantified. CD4⁺ T cells were isolated from the peripheral blood of healthy volunteers and treated with ovalbumin (OVA) and Th2 inducers. After MALAT1 and miR-135b-5p levels changed in CD4⁺ T cells, the proportion of IL-4-expressing cells and the levels of IL-4 and GATA-3 in OVA-induced CD4⁺ T cells were determined. Binding relationships among MALAT1, miR-135b-5p, and GATA-3 were predicted and verified. Rescue experiments were performed to confirm the role of the MALAT1/miR-135b-5p/GATA-3 axis in Th2 differentiation of CD4⁺ T cells. MALAT1, IL-4, and GATA-3 expression was upregulated, whereas miR-135b-5p expression was downregulated, in patients with AR. MALAT1 knockdown or miR-135b-5p overexpression in CD4⁺ T cells notably decreased the proportion of IL-4-expressing cells and downregulated GATA-3 and IL-4 expression in OVA-induced CD4⁺ T cells. MALAT1 and GATA-3 exhibited competitive binding toward miR-135b-5p. MALAT1 facilitated CD4⁺ T cell Th2 differentiation via the miR-135b-5p/GATA-3 axis. MALAT1 facilitated AR development by facilitating CD4⁺ T cell Th2 differentiation via the miR-135b-5p/GATA-3 axis. This study may provide guidance for clinical treatment of AR.

Ranolazine Inhibits Pyroptosis via Regulation of miR-135b in the Treatment of Diabetic Cardiac Fibrosis

Diabetic cardiomyopathy (DCM) is a major cardiovascular complication of diabetes mellitus (DM), and cardiac fibrosis is a characteristic pathological manifestation of DCM. DCM can be exacerbated by pyroptosis, and pyroptosis is a potential target of microRNAs (miRNAs). miR-135b is involved in delaying the progression of numerous cardiovascular diseases, Nonetheless, the role of miR-135b in diabetic cardiac fibrosis is unclear. Ranolazine is a piperazine derivative and is effective for the treatment of cardiovascular disease. The purpose of the study was to elucidate the mechanism of action of ranolazine against diabetic cardiac fibrosis and to investigate the role of miR-135b in this process. Functional and structural changes in the rat heart were examined by echocardiography, hematoxylin-eosin (H&E) and Masson staining. Immunohistochemistry was used to assess the expression of caspase-1, interleukin-1β (IL-1β), gasdermin D (GSDMD), transforming growth factor-β1 (TGF-β1), collagen I and collagen III in the rat left ventricle. Western blot and immunofluorescence were used to detect the protein expression of caspase-1, IL-1β, GSDMD, TGF-β1, collagen I and collagen III proteins, and the mRNA levels were determined using fluorescent quantitative PCR. Ranolazine reduced pyroptosis and inhibited collagen deposition, improving cardiac function in rats. Ranolazine increased miR-135b expression in high glucose-treated cardiac fibroblasts, and miR-135b directly bound to caspase-1. Interference with miR-135b reduced the effects of ranolazine on pyroptosis and collagen deposition. Ranolazine treatment of diabetic cardiac fibrosis inhibited pyroptosis and collagen deposition by upregulating miR-135b. Our study provides a solid theoretical basis for understanding the pathogenesis of diabetic cardiac fibrosis and the clinical use of ranolazine in the treatment of DCM.

Emerging Advances of Non-coding RNAs and Competitive Endogenous RNA Regulatory Networks in Asthma

Asthma is a chronic inflammatory disease characterized by airway remodeling and bronchial hyperresponsiveness. A variety of effector cells and cytokines jointly stimulate the occurrence of inflammatory response in asthma. Although the pathogenesis of asthma is not entirely clear, the possible roles of non-coding RNAs (ncRNAs) have been recently demonstrated. NcRNAs are non-protein-coding RNA molecules, such as circular RNAs (circRNAs), long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), which are involved in the regulation of a variety of biological processes. Mounting studies have shown that ncRNAs play pivotal roles in the occurrence and progression of asthma via competing endogenous RNA (ceRNA) regulatory networks. However, the specific mechanism and clinical application of ncRNAs and ceRNA regulatory networks in asthma have not been fully elucidated, which are worthy of further investigation. This paper comprehensively summarized the current progress on the roles of miRNAs, lncRNAs, circRNAs, and ceRNA regulatory networks in asthma, which can provide a better understanding for the disease pathogenesis and is helpful for identifying novel biomarkers for asthma.

MiR-140 suppresses airway inflammation and inhibits bronchial epithelial cell apoptosis in asthma by targeting GSK3β

AIM OF THE STUDY

Asthma is a common and complex chronic inflammatory disease induced by genetic and environmental factors that affects the airways of the lungs. MicroRNAs (miRNAs) are key regulators of various cellular processes and have been shown to be critically involved in asthma progression. The objective of our study was to clarify the function and molecular mechanism of miR-140 in the progression of asthma.

MATERIALS AND METHODS

MiR-140 expression was evaluated using RT-qPCR. Pathological changes in the lung tissue were confirmed using HE and PAS staining. The levels of IL-5, TGF-β1, and IL-13 in the serum or bronchioalveolar lavage fluid were detected with an ELISA. Cellular apoptosis was measured using a TUNEL assay. The levels of Bax, Bcl-2, Cleaved caspase-3, and glycogen synthase kinase-3β (GSK-3β) were verified with a western blot. GSK3β expression was also confirmed by immunohistochemistry. The binding ability between miR-140 and GSK3β was confirmed using a luciferase reporter assay, RNA immunoprecipitation (RIP) assay and Pull-down assay.

RESULTS

MiR-140 was markedly downregulated in asthmatic mice. Additionally, miR-140 weakened airway inflammation and bronchial epithelial cell apoptosis in asthmatic mice. Further experiments revealed that miR-140 negatively regulated GSK3β expression and could bind to GSK3β in asthma. Finally, rescue assays demonstrated that GSK3β overexpression rescued the effects of miR-140 on asthma progression.

CONCLUSION

MiR-140 targeted GSK3β to suppress airway inflammation and inhibit bronchial epithelial cell apoptosis in asthma.