Non-coding RNA regulation of macrophage function in asthma

RNA modulation in asthma: unraveling the role of splicing and non-coding RNAs in disease pathogenesis

OBJECTIVE

To synthesize the current understanding of RNA-based regulatory mechanisms, focusing on how RNA splicing and non-coding RNAs shape immune responses and airway remodeling in asthma, with the aim of exploring their potential as therapeutic targets for asthma treatment.

DATASOURCE

Recent advances and emerging research in molecular biology and immunology related to RNA splicing, non-coding RNAs (lncRNAs, circRNAs), and N6-methyladenosine (m6A) RNA methylation in asthma pathogenesis.

STUDY SELECTIONS

The review incorporates studies highlighting the roles of alternative RNA splicing, non-coding RNAs (lncRNAs and circRNAs), and RNA methylation (m6A) in regulating immune and inflammatory pathways involved in asthma.

RESULTS

RNA splicing events, non-coding RNAs, and m6A RNA methylation are critical in modulating immune dysregulation, airway remodeling, and inflammation in asthma. These mechanisms influence key inflammatory pathways, mRNA stability, and the overall immune landscape of the disease.

CONCLUSION

RNA splicing and non-coding RNAs represent promising areas of research for understanding asthma's immune pathology and hold potential as novel therapeutic targets for more effective treatment strategies.

New mechanisms in diisocyanate-mediated allergy/toxicity: are microRNAs in play?

PURPOSE OF REVIEW

To describe recent findings of diisocyanate-mediated mechanisms in allergy and toxicology by addressing the role of microRNA (miR) in immune responses that may contribute to the development of occupational asthma (OA).

RECENT FINDINGS

Studies of diisocyanate asthma have traditionally focused on the immune and inflammatory patterns associated with diisocyanate exposures; however, recognized knowledge gaps exist regarding the detailed molecular mechanism(s) of pathogenesis. Recent studies demonstrate the critical role endogenous microRNAs play as gene regulators in maintaining homeostasis of the human body, and in the pathophysiology of many diseases including asthma. Given that diisocyanate-OA shares many pathophysiological characteristics with asthma, it is likely that miR-mediated mechanisms are involved in the pathophysiology of diisocyanate-OA. Recent reports have shown that changes in expression of endogenous miRs are associated with exposure to the occupationally relevant diisocyanates, toluene diisocyanate (TDI) and methylene diphenyl diisocyanate (MDI). Continued mechanistic study of these relevant miRs may lead to the development of novel biomarkers of occupational exposure and/or provide efficacious targets for therapeutic strategies in diisocyanate asthma.

SUMMARY

The molecular mechanisms underlying diisocyanate-OA pathophysiology are heterogeneous and complicated. In this review, we highlight recent research into the roles and potential regulation of miRs in diisocyanate-OA.

Unraveling asthma through single-cell RNA sequencing in understanding disease mechanisms

OBJECTIVE

To elucidate the fundamental principles of single-cell RNA sequencing (scRNA-seq) and summarize its application in asthma research, aiming to enhance understanding of asthma pathophysiology and guide future research directions.

DATASOURCE

Recent advances and emerging research in scRNA-seq and its role in the pathogenesis of asthma.

STUDY SELECTIONS

This review incorporates studies that analyzed the heterogeneity of asthma cell types and their functional states using scRNA-seq, with particular emphasis on immune cells and airway remodeling. The selection of specific cell types and markers was based on their relevance to asthma pathogenesis, and we discuss the rationale for favoring certain scRNA-seq technologies in these investigations.

RESULTS

ScRNA-seq technology has provided insights into the key mechanisms underlying inflammation and airway remodeling in asthma. It has uncovered the diversity of immune cell subtypes and their specific roles in asthma pathogenesis, revealing critical pathways that contribute to disease progression. These findings offer a theoretical foundation for the development of targeted therapeutic strategies, paving the way for personalized medicine and improved patient outcomes.

CONCLUSION

ScRNA-seq reveals the complex heterogeneity and functional roles of immune cells in asthma, offering key insights into disease mechanisms and the potential for targeted therapies. However, challenges remain, such as the need for further refinement of data integration methods and addressing the limited clinical applicability of current findings. Future research should focus on overcoming these limitations, improving cell type annotation, and expanding studies to include longitudinal and clinical data to better understand disease dynamics and therapy responses.

SLAMF7 is a key molecule that promotes M1 polarization in lung tissue macrophages of high-fat diet-fed asthma mice model

OBJECTIVE

Investigating the regulatory role of Signaling lymphocyte activation molecule family 7 (SLAMF7) in the pathogenesis of asthma in a high fat-fed (HFD) mouse model, providing targets for treating obese asthma.

METHODS

We constructed a mouse model of obese asthma, and Quantitative real-time RT-PCR (qPCR) for the detection of mRNA levels of SLAMF7 and M1 polarization markers of macrophages. Lung tissue levels of SLAMF7 protein, macrophage M1 polarization markers, and neutrophil markers were measured by Western blotting. The proportions of SLAMF7+ macrophages and neutrophils in bronchoalveolar lavage fluid (BALF) were determined by flow cytometry. Neutrophil inflammatory cytokine levels were determined by Enzyme-linked immunosorbent assay (ELISA). Immunofluorescence performed the colocalization of SLAMF7 and inducible nitric oxide synthase (iNOS). The regulation of SLAMF7 on M1 polarization of macrophages was verified by cell experiments.

RESULTS

The group of HFD asthmatic mice had more severe airway inflammation and mucus secretion. They also had higher SLAMF7 levels, airway neutrophil inflammation and M1 polarization of macrophages in lung tissue. SLAMF7 overexpression increased M1 polarization, and SLAMF7 knockdown decreased M1 polarization. The expression change of SLAMF7 affects the expression of NR4A1 and RUNX3, inhibiting NR4A1 and promoting RUNX3.

CONCLUSION

SLAMF7 expression is increased in obese asthma mice, accompanied by neutrophil infiltration and enhanced M1 polarization. SLAMF7 promotes M1 polarization may be through the NR4A1-RUNX3 axis, suppressing NR4A1, and promoting RUNX3.

Copy Number Variation in Asthma: An Integrative Review

Asthma is a complex disease with varied clinical manifestations resulting from the interaction between environmental and genetic factors. While chronic airway inflammation and hyperresponsiveness are central features, the etiology of asthma is multifaceted, leading to a diversity of phenotypes and endotypes. Although most research into the genetics of asthma focused on the analysis of single nucleotide polymorphisms (SNPs), studies highlight the importance of structural variations, such as copy number variations (CNVs), in the inheritance of complex characteristics, but their role has not yet been fully elucidated in asthma. In this context, an integrative review was conducted to identify the genes and pathways involved, the location, size, and classes of CNVs, as well as their contribution to asthma risk, severity, control, and response to treatment. As a result of the review, 16 articles were analyzed, from different types of observational studies, such as case-control, cohort studies and genotyped-proband or trios design, that have been carried out in populations from different countries, ethnicities, and ages. Chromosomes 12 and 17 were the most studied in three publications each. CNVs located on 12 chromosomes were associated with asthma, the majority being found on chromosome 6p and 17q, of the deletion type, encompassing 30 different coding-protein genes and one pseudogene region. Six genes with CNVs were identified as significant expression quantitative locus (eQTLs) with mean expression in asthma-related tissues, such as the lung and whole blood. The phenotypic variability of asthma may hinder the clinical application of these findings, but the research shows the importance of investigating these genetic variations as possible biomarkers in asthma patients.

Exploring the Regulatory Mechanism of CXCL16 Molecule-Related Antigen Presentation Using lncRNA-mRNA Co-Expression Network Analysis

Aim

To investigate the regulatory mechanism of CXCL16 molecule-related Aspergillus fumigatus (A.f.) extract-induced antigen presentation in a mouse asthma model based on the long non-coding RNA (lncRNA) and mRNA expression profile.

Methods

CXCL16 knockout mice and wild-type mice were administered with A.f. extract by intratracheal instillations to induce asthma airway inflammation. High throughput chip sequencing was used to screen for lncRNA and mRNA expression profile differences in lung tissue between the groups. A lncRNA-mRNA co-expression network was constructed through gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Wild-type mice received intraperitoneal injections with CXCL16 neutralizing antibodies, and the bioinformatics and inflammation results were validated using RT-PCR and ELISA.

Results

Compared with wild-type mice, CXCL16 knockout mice showed 120 lncRNA and 388 mRNA upregulated in lung tissue, while 1984 lncRNA and 301 mRNA were downregulated. The constructed lncRNA-mRNA co-expression network included 244 differentially expressed lncRNAs and 49 differentially expressed mRNAs. Among them, the core network's expression of the hub gene Idh1 and the top four lncRNAs was validated in the CXCL16 neutralizing antibody asthma model.

Conclusion

A comprehensive biological analysis of the lncRNA-mRNA co-expression network explored key genes and pathways, providing new insights for understanding their mechanisms and discovering new targets for asthma induced by A.f. The four differentially expressed key lncRNAs in the co-expression network (NONMMUT026034, NONMMUT028184, NONMMUT016537, and NONMMUT043155) can serve as intervention targets for CXCL16 molecular regulation of antigen presentation in mice asthma models.

Macrophage Polarizations in the Placenta and Lung are Associated with Bronchopulmonary Dysplasia

The intricate interplay between macrophage polarization and placenta vascular dysfunction has garnered increasing attention in the context of placental inflammatory diseases. This study delves into the complex relationship between macrophage polarization within the placenta and its potential impact on the development of vascular dysfunction and inflammatory conditions. The placenta, a crucial organ in fetal development, relies on a finely tuned balance of immune responses for proper functioning. Disruptions in this delicate equilibrium can lead to pathological conditions, including inflammatory diseases affecting the fetus and newborn infant. We explored the interconnectedness between placental macrophage polarization and its relevance to lung macrophages, particularly in the context of early life lung development. Bronchopulmonary dysplasia (BPD), the most common chronic lung disease of prematurity, has been associated with abnormal immune responses, and understanding the role of macrophages in this context is pivotal. The investigation aims to shed light on how alterations in placental macrophage polarization may contribute to lung macrophage behavior and, consequently, influence the development of BPD. By unraveling the intricate mechanisms linking macrophage polarization, placental dysfunction and BPD, this research seeks to provide insights that could pave the way for targeted therapeutic interventions. The findings may offer novel perspectives on preventing and managing placental and lung-related pathologies, ultimately contributing to improved maternal and neonatal health outcomes.

Regulation of Macrophage Polarization in Allergy by Noncoding RNAs

Allergy is a type 2 immune reaction triggered by antigens known as allergens, including food and environmental substances such as peanuts, plant pollen, fungal spores, and the feces and debris of mites and insects. Macrophages are myeloid immune cells with phagocytic abilities that process exogenous and endogenous antigens. Upon activation, they can produce effector molecules such as cytokines as well as anti-inflammatory molecules. The dysregulation of macrophage function can lead to excessive type 1 inflammation as well as type 2 inflammation, which includes allergic reactions. Thus, it is important to better understand how macrophages are regulated in the pathogenesis of allergies. Emerging evidence highlights the role of noncoding RNAs (ncRNAs) in macrophage polarization, which in turn can modify the pathogenesis of various immune-mediated diseases, including allergies. This review summarizes the current knowledge regarding this topic and considers three classes of ncRNAs: microRNAs, long ncRNAs, and circular ncRNAs. Understanding the roles of these ncRNAs in macrophage polarization will provide new insights into the pathogenesis of allergies and identify potential novel therapeutic targets.