Epithelial miR-141 regulates IL-13-induced airway mucus production

Middle Ear microRNAs Drive Mucin Gene Response

OBJECTIVE(S)

To investigate the role of microRNA-378 (miR-378) in the regulation of mucin gene expression and inflammatory response in human middle ear epithelial cells (HMEEC) during bacterial infection by non-typeable Haemophilus influenzae (NTHi).

METHODS

Human middle ear epithelial cells (HMEEC) were cultured and transfected with miR-378 or control miRNA. Post-transfection, cells were exposed to NTHi lysates. mRNA levels of MUC5B, MUC5AC, and IL-8 were quantified using RT-qPCR, and promoter activity was measured via luciferase assays. The effects of miR-378 on mucin and cytokine gene expression were analyzed.

RESULTS

Transfection with miR-378 significantly increased the expression of MUC5B (3.6 fold, p < 0.01), MUC5AC (19.1 fold, p < 0.01), and IL-8 (2.01 fold, p < 0.05) in HMEEC. NTHi exposure reduced MUC5B (1.385 fold, p < 0.05) and MUC5AC (1.61 fold, p < 0.05) gene expression in miR-378 transfected cells but significantly increased IL-8 levels (1.32 fold, p < 0.05). Luciferase assays showed that miR-378 upregulated the promoter activity of MUC5B (1.4 fold, p < 0.01) and MUC5AC (1.6 fold, p < 0.01) genes, indicating its role in transcriptional regulation.

CONCLUSION

miR-378 plays a crucial role in promoting mucin overproduction and an inflammatory response in the middle ear epithelium during OM. Targeting miR-378 could offer a novel therapeutic strategy for preventing the progression from AOM to COM.

LEVEL OF EVIDENCE

NA Laryngoscope, 135:1815-1820, 2025.

Connecting the Dots: How MicroRNAs Link Asthma and Atherosclerosis

Asthma and atherosclerosis are chronic conditions with distinct pathophysiologies, but overlapping inflammatory mechanisms that suggest a potential common regulatory framework. MicroRNAs (miRNAs), small non-coding RNA molecules that modulate gene expression post-transcriptionally, could be key players in linking these disorders. This review outlines how miRNAs contribute to the complex interplay between asthma and atherosclerosis, focusing on key miRNAs involved in inflammatory pathways, immune cell regulation and vascular remodeling. We discuss specific miRNAs, such as miR-155, miR-21 and miR-146a, which have been shown to modulate inflammatory cytokine production and T cell differentiation, impacting respiratory and cardiovascular health. The common miRNAs found in both asthma and atherosclerosis emphasize their role as potential biomarkers, but also as therapeutic targets. Understanding these molecular connections may unlock novel approaches for innovative, integrated treatment strategies that address both conditions and may significantly improve patient outcomes. Further research is needed to explore mechanistic pathways and validate the translational potential of miRNA-based interventions in preclinical and clinical settings.

A causal effects of neutrophil extracellular traps and its biomarkers on acute respiratory distress syndrome: a two-sample Mendelian randomization study

Previous studies have indicated an association between neutrophil extracellular traps (NETs) and acute respiratory distress syndrome (ARDS). This study aimed to investigate the potential causal effects of NETs and NETs-related biomarkers on ARDS or vice-versa. A two-sample Mendelian randomization (MR) utilizing genome-wide association studies (GWAS) data was employed to analyze the causality. The primary analysis was conducted using inverse-variance weighted (IVW) methods; weighted median, MR-Egger, and weighted model methods were used to validate the results. Horizontal pleiotropy and outlier detection were assessed via MR-Egger and MR pleiotropy residual sum and outlier (MR-PRESSO), respectively; Cochran's Q test evaluated heterogeneity, while Leave-one-out analyses were used to evaluate the presence of predominant instrumental variables (IVs). IVW method suggested causal associations between genetically predicted IL-13 and a higher risk of ARDS [OR (95%CI) = 1.52 (1.03-2.23), P = 0.047], while there was no causal effect of other factors on ARDS (all P > 0.05). Also, ARDS had no effect on NETs and NETs-related biomarkers (all P > 0.05). Cochran's Q confirmed no significant heterogeneity. MR-Egger regression ruled out horizontal pleiotropy's influence, and MR-PRESSO analysis identified no outliers, reinforcing the study's findings. This MR study established a causal relationship between IL-13 and ARDS, suggesting its potential role as a therapeutic target and biomarker of ARDS. Future work should delve into the underlying mechanisms and clinical applications.

Single-cell RNA Sequencing Analysis of Sputum Cell Transcriptomes Reveals Pathways and Communication Networks That Contribute to the Pathogenesis of Asthma

Background

Asthma is driven by complex interactions amongst structural airway cells, cells of the immune system, and the environmental. While sputum cell characterization has been instrumental in studying asthma pathogenesis and refining treatment strategies, the nuances of cellular transcriptomes and intercellular communication in asthmatic sputum remain poorly understood.

Methods

We employed single-cell RNA sequencing to analyze cells isolated form the sputum from 16 asthma patients and 8 non-asthmatic controls. Cell identities were established using curated marker genes and SingleR annotation. We compared cell-specific gene expression and communication networks between asthmatic and control groups, correlating findings with distinct pathways that were dysregulated in asthma.

Findings

37,565 cellular transcriptomes were captured and analyzed. 15 distinct cell populations were identified, including various macrophages, monocytes, dendritic cells, and lymphocytes, along with rare cell types such as mast cells, innate lymphoid cells, bronchial epithelial cells, and eosinophils. Intercellular communication analysis indicated heightened signaling activity in asthma compared to controls, particularly in CD4+ T cells and dendritic cells which exhibited the most significant increases in RNA expression of outgoing signaling molecules. Notably, the ADAM12-SDC4 and CCL22-CCR4 ligand-receptor pathways demonstrated the strongest shifts between asthma and control subjects, particularly between dendritic cells and CD4 lymphocytes.

Interpretation

SC RNA seq profiling the asthma cellular transcriptome analysis of sputum highlights both innate and adaptive immune mechanisms that are significantly amplified in asthma. The elevated expression of ADAM12-SCD4 and CCL22-CC4 point to their critical role in asthma pathogenesis, suggesting potential avenues for targeted therapies and improved management of this chronic condition.

Research in context

Evidence Before This Study: Asthma is a chronic inflammatory disease of the airways driven by intricate interactions between airway structural and immune cells. Previous transcriptomic studies have focused on bulk RNA samples from the airway, leaving significant gaps in our understanding of the cellular dynamics that characterize the disease.Added Value of This Study: This study pioneers the use of single-cell RNA sequencing on sputum samples from patients with asthma, revealing a detailed landscape of cell phenotypes and dynamic communication patterns that distinguish asthmatic individuals from those without the disease. Notably, heightened intercellular communication was observed in asthma, particularly between CD4+ T cells and dendritic cells, confirming that there is a robust network of interactions between immune and structural cells. The notable increase of ADAM12-CCR4 communication from dendritic cells to other cell populations further emphasizes the dysregulation present in asthma.Implications of All Available Evidence: Our transcriptomic profiling illuminates distinct and amplified communication pathways involving CD4+ T cells and dendritic cells, aligning with established paradigms of both adaptive and innate immune responses in asthma pathogenesis. The identification of ADAM12 and CCR4 pathway dysregulation adds a critical layer to our understanding of the molecular mechanisms underpinning asthma, paving the way for potential therapeutic targets and personalized treatment strategies. Single cell profiling of the sputum has the capacity to characterize the breadth of cellular phenotypes, their functional status, and the communication in the airway at a level not previously attainable.

Airway epithelial cells as drivers of severe asthma pathogenesis

Our understanding of the airway epithelium's role in driving asthma pathogenesis has evolved over time. From being regarded primarily as a physical barrier that could be damaged via inflammation, the epithelium is now known to actively contribute to asthma development through interactions with the immune system. The airway epithelium contains multiple cell types with specialized functions spanning barrier action, mucociliary clearance, immune cell recruitment, and maintenance of tissue homeostasis. Environmental insults may cause direct or indirect injury to the epithelium leading to impaired barrier function, epithelial remodelling, and increased release of inflammatory mediators. In severe asthma, the epithelial barrier repair process is inhibited and the response to insults is exaggerated, driving downstream inflammation. Genetic and epigenetic mechanisms also maintain dysregulation of the epithelial barrier, adding to disease chronicity. Here, we review the role of the airway epithelium in severe asthma and how targeting the epithelium can contribute to asthma treatment.

NOTCH pathway was involved in Kaempferol 3-O-gentiobioside attenuated airway inflammation and mucus hypersecretion

Allergic asthma is an inflammatory condition characterized by the release of pro-inflammatory cytokines and the expansion of mucus-producing cells. This research aimed to evaluate the impact of Kaempferol 3-O-gentiobioside (K3G), extracted from Sauropus spatulifolius Beille leaves, on inflammatory cytokine secretion and mucus overproduction in IL-13-stimulated airway epithelial cells (16HBE cells) and ovalbumin (OVA)-induced allergic asthma mouse models. Studies have found that K3G significantly reduces the release of pro-inflammatory cytokines (IgE, TNF-α, histamine, IL-1β, IL-6, and IL-8) induced by IL-13. It also mitigating the expression of the mucin5AC (MUC5AC). Additionally, K3G also downregulated the expression of NLRP3, TLR4, p-IκBα, and p-P65 proteins. In an OVA-induced mouse asthma model, K3G treatment reduced the secretion of pro-inflammatory cytokines, and inhibited the increase in mucus-secreting cells in a dose-dependent manner. Furthermore, exposure to IL-13 and OVA increased the expression of NOTCH signaling receptors in both 16HBE cells and lung tissues of the mice. K3G treatment effectively targeted NOTCH1 and inhibits activation of the NOTCH pathway. In conclusion, K3G alleviates asthma-related airway alterations by suppressing inflammatory cytokines and excessive mucus secretion via the NOTCH signaling pathway. These results indicate the therapeutic promise of K3G in treating allergic asthma.

AAV-mediated MUC5AC siRNA delivery to prevent mucociliary dysfunction in asthma

The main structural components of mucus produced in the lung are mucin 5B (MUC5B) and mucin 5AC (MUC5AC) where a relatively higher expression of MUC5B is typical in health. In the lungs of individuals with asthma, there is a shift from MUC5B to MUC5AC as the predominantly secreted mucin which has been shown to impair mucociliary clearance (MCC) and increase mucus plug formation in the airways. Given its role in asthmatic lung disease, MUC5AC represents a potential therapeutic target where a gene delivery approach could be leveraged to modulate its expression. For these purposes, we explored adeno-associated virus serotype 6 (AAV6), as a lung-tropic viral gene vector to target airway epithelial cells and reduce MUC5AC expression via siRNA delivery. We confirmed that AAV6 was able to transduce epithelial cells in the airways of healthy mice with high transgene expression in mucus-secreting goblet cells. Using multiple particle tracking analysis, we observed that AAV6 was capable of penetrating both normal and MUC5AC-enriched mucus barriers. Successful transduction with AAV6 was also achieved in IL-13 stimulated human airway epithelial (HAE) cells differentiated at air-liquid interface (ALI). AAV6 expressing MUC5AC-targeting siRNA was evaluated as a prophylactic treatment in HAE cell cultures before IL-13 challenge. IL-13 stimulated HAE cultures treated with AAV6-MUC5AC siRNA had significantly reduced MUC5AC mRNA and protein expression compared to untreated controls. Mucociliary transport in IL-13 stimulated HAE cultures was also maintained and comparable to healthy controls following AAV6-MUC5AC siRNA treatment. Together, these findings support that AAV6 may be used as an inhaled gene therapy to suppress MUC5AC overexpression and restore normal airway clearance function in asthma.

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.

Innate Immunity and Asthma Exacerbations: Insights From Human Models

Asthma is a common chronic respiratory disease characterized by the presence of airway inflammation, airway hyperresponsiveness, and mucus hypersecretion. Repeated asthma exacerbations can lead to progressive airway remodeling and irreversible airflow obstruction. Thus, understanding and preventing asthma exacerbations are of paramount importance. Although multiple endotypes exist, asthma is most often driven by type 2 airway inflammation. New therapies that target specific type 2 mediators have been shown to reduce the frequency of asthma exacerbations but are incompletely effective in a significant number of asthmatics. Furthermore, it remains unknown whether current treatments lead to sustained changes in the airway or if targeting additional pathways may be necessary to achieve asthma remission. Activation of innate immunity is the initial event in the inflammatory sequence that occurs during an asthma exacerbation. However, there continue to be critical gaps in our understanding of the innate immune response to asthma exacerbating factors. In this review, we summarize the current understanding of the role of innate immunity in asthma exacerbations and the methods used to study them. We also identify potential novel therapeutic targets for asthma and future areas for investigation.

Integrated analysis reveals that EGR1 promotes epithelial IL33 production in T2 asthma

BACKGROUND

Airway epithelial cells constitute the first line of defense against external noxious stimuli and play crucial roles in the release of epithelial inflammatory cytokines (IL33, IL25 and TSLP), initiating airway allergic inflammatory diseases such as asthma. IL33 plays critical physiological processes in T2-endotype asthma. However, the mechanisms by which allergen exposure triggers IL33 release from airway epithelial cells remain unclear.

METHODS

Integrated bioinformatic analysis and transcriptional analysis of bulk RNA-seq and single cell RNA-seq (scRNA-seq) data were used to identify core genes and determine the internal gene network associated with IL33. The expression of EGR1 was subsequently analyzed in vitro in the BEAS-2B cell line and in vivo in a house dust mite (HDM)-induced mouse asthma model. The functional experiments of EGR1 were investigated in vitro via siRNA knockdown and over-expressed plasmid. Chromatin immunoprecipitation (ChIP)-PCR and dual-luciferase reporter assay validation were subsequently performed to investigate the mechanisms by which EGR1 regulates IL33 secretion.

RESULTS

Bulk RNA-seq and scRNA-seq data identified EGR1 as an epithelial cell-derived gene implicated in IL33 expressions in asthma. The comprehensive analysis of multiple datasets indicated that the high EGR1 expression in epithelial cells may suggest a mechanistic basis of T2-endotype childhood asthma. Moreover, we verified that the expressions of EGR1 in airway epithelial cells were elevated both in vitro and in vivo asthma models. EGR1 regulated the production of IL33. Ultimately, ChIP and luciferase reporter assays confirmed that transcription factor EGR1 directly regulate the transcription of IL33 mRNA.

CONCLUSIONS

Our integrated bioinformatic analysis elucidated that EGR1 directly regulates the production of IL33 in T2-asthma and provide insights underlying the progression of asthma.

The impaired response of nasal epithelial cells to microplastic stimulation in asthma and COPD

Microplastic particles from the air are inhaled and accumulate in the lungs, potentially causing immunological reactions and airway tissue injury. This study aimed to evaluate the biological effects of polyamide fibres on nasal epithelium co-cultivated with macrophages in control, asthma, and COPD groups. Nasal epithelial cells alone or in co-culture with monocyte-derived macrophages were exposed to polyamide fibres for 48 h. We identified 8 differentially expressed genes (DEGs) in controls, 309 DEGs in asthma (including ANKRD36C, BCL2L15, FCGBP, and IL-19), and 22 DEGs in COPD (e.g., BCL2L15, IL-19, CAPN14, PGBD5, PTPRH), particularly in epithelial/moMφ co-cultures. Microplastic exposure induced inflammatory cytokine secretion only for IL-8 production in controls (epithelial/ moMφs co-culture) and asthmatic (monoculture) epithelial cells in contrast to PM2.5, which was a strong inflammatory inducer. Gene Ontology analysis revealed that microplastic exposure affected sterol and cholesterol biosynthesis, secondary alcohol metabolism, and acetyl-CoA metabolism in asthma, and cell motility, chemokine signaling, leukocyte migration, and chemotaxis in COPD. Microplastic stimulation altered the response of airway epithelial cells in obstructive lung diseases differently than in controls, linking to Th2 inflammation, stress response modulation, and carcinogenesis. Asthmatic and COPD epithelial cells are more susceptible to damage from microplastic fibre exposure.

Impact of IL13 genetic polymorphisms on COPD susceptibility in the Chinese Han population

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by persistent respiratory symptoms and airflow limitation. Interleukin-13 (IL13), associated with T-helper type 2 cells, plays a crucial role in COPD pathophysiology. This study aimed to investigate the relationship of single nucleotide polymorphisms (SNPs) in IL13 to COPD risk.

METHODS

Five candidate SNPs of IL13 were genotyped using MassARRAY iPLEX platform in a cohort of472 COPD patients and 472 healthy controls. Logistic regression analysis was used to calculate odds ratios (ORs) and 95 % confidence intervals (CIs). Additionally, Multifactor dimensionality reduction (MDR) software was utilized to assess the combined impact of SNP-SNP interactions on COPD risk.

RESULTS

IL13 rs20541 (OR: 1.24, p: 0.028), rs1295685 (OR: 1.31, p: 0.006), rs848 (OR: 1.27, p: 0.016), and rs847 (OR: 1.30, p: 0.007) were associated with COPD risk. Moreover, IL13 variants were related to the increased COPD risk in females, individuals aged ≥68 year, non-smokers or non-drinkers. The optimal multi-locus model was identified as the combination of rs20541 and rs1295685.

CONCLUSION

Our findings indicated the association between IL13 variants and an elevated risk of developing COPD, especially rs1295685 and rs847. These findings could have implications for understanding the role of IL13 variants in COPD predisposition.

Novel insights into the study of goblet cell hypersecretion in allergic rhinitis

Goblet cell hypersecretion is a hallmark of airway inflammation and is driven by complex neuroimmune regulation involving submucosal glands and goblet cells. Although studies have focused on mast cell degranulation as a critical driver of nasal secretion, the role of goblet cells in this process is relatively under-researched. In allergic airway inflammation, goblet cells exhibit metaplasia and hypersecretion. However, allergen exposure does not directly trigger goblet cell degranulation, raising questions regarding the underlying mechanisms of these reactions. The activation of enteric neurons promotes goblet cell degranulation by stimulating the calcitonin gene-related peptide (CGRP)-receptor active modification protein-1 (RAMP1) axis. Meanwhile, airway goblet cells express various neuropeptide receptors, and their activation by neuropeptides such as substance P and CGRP induces mucus secretion, exacerbating allergic rhinitis-associated hypersecretion. Thus, although previously less recognised, the neuron-goblet cell signalling axis plays a critical role in allergic rhinitis mucus secretion. This review highlights current research on the neuroimmune mechanisms underlying goblet cell metaplasia and degranulation, focusing on allergic rhinitis, so as to guide clinical treatment strategies.

Epithelial and immune transcriptomic characteristics and possible regulatory mechanisms in asthma exacerbation: insights from integrated studies

Background

Asthma exacerbation significantly contribute to disease mortality and result in heightened health care expenditures. This study was aimed at gaining important new insights into the heterogeneity of epithelial and immune cells and elucidating key regulatory genes involved in the pathogenesis of asthma exacerbation.

Methods

Functional enrichment, pseudotime, metabolism and cell-cell communication analyses of epithelial cells and immune cells in single-cell RNA sequencing (scRNA-seq) dataset were applied. Immune infiltration analysis was performed in bulk RNA sequencing (bulk RNA-seq) dataset. Key regulatory genes were obtained by taking the intersection of the differentially expressed genes (DEGs) between control and asthma group in epithelial cells, immune cells and bulk RNA-seq data. Asthma animal and in vitro cell line models were established to verify the key regulatory genes expression by employing quantitative reverse transcription polymerase chain reaction (qRT-PCR).

Results

ScRNA-seq analysis identified 7 epithelial subpopulations and 14 distinct immune cell types based on gene expression profiles. Further analysis demonstrated that these cells manifested high heterogeneity at the levels of functional variations, dynamics, communication patterns and metabolic changes. Notably, TMPRSS11A, TUBA1A, SCEL, ICAM4, TMPRSS11B, IGFBP2, CLC, NFAM1 and F13A1 were identified as key regulatory genes of asthma. The results of the qRT-PCR demonstrated that the 9 key regulatory genes were involved in asthma.

Conclusions

We systematically explored epithelial and immune characteristics in asthma exacerbation and identified 9 key regulatory genes underlying asthma occurrence and progression, which may be valuable for providing new insights into the cellular and molecular mechanisms driving asthma exacerbations.

Characterization of a chitinase from Trichinella spiralis and its immunomodulatory effects on allergic airway inflammation in mice

BACKGROUND

A fundamental tenet of the hygiene theory is the inverse association between helminth infections and the emergence of immune-mediated diseases. Research has been done to clarify the processes by which helminth-derived molecules can inhibit immunological disorders. This study aimed to evaluate the ability of Trichinella spiralis chitinase (Ts-chit) to ameliorate the symptoms of allergic airway inflammation.

METHODS

Recombinant Trichinella spiralis chitinase (rTs-chit) was expressed in Escherichia coli BL21, and its structural homology to murine acidic mammalian chitinase (AMCase) was comprehensively analyzed. The expression of Ts-chit was examined across all T. spiralis life stages. To explore its immunomodulatory potential, a murine model of allergen-induced airway inflammation was established. The effects of rTs-chit were evaluated by assessing airway hyperresponsiveness and cytokine profiles in bronchoalveolar lavage fluid and performing detailed histopathological and immunohistochemical analyses.

RESULTS

Recombinant Ts-chit (rTs-chit) was successfully expressed in E. coli BL21, showing strong structural similarity to murine acidic mammalian chitinase (AMCase). Expression profiling revealed that Ts-chit is present throughout all stages of the T. spiralis life cycle. In an allergic airway inflammation model, rTs-chit reduced weight loss and lung inflammation, lowering inflammatory cell infiltration and Th2 cytokines (IL-4, IL-5, IL-13) while increasing the immunosuppressive cytokine IL-10. Additionally, rTs-chit treatment decreased the expression of GATA3, arginase-1, MCP-1, CCL-11, and AMCase, along with reducing OVA-specific IgE, IgG, and IgG1 levels, suggesting its potential as an immunomodulatory agent.

CONCLUSIONS

This study highlights rTs-chit's potential as a therapeutic agent for allergic airway diseases, leveraging its structural similarity to host chitinases to regulate Th2 responses and inflammatory pathways. The findings provide new insights into helminth-derived proteins as promising candidates for immune-based therapies.

Transforming growth factor-β3/Smad2/Smad3 signaling pathway inhibition and autophagy by the Yunpi-Xiefei-Huatan decoction ameliorated airway inflammation and mucus hypersecretion in asthmatic rats

ETHNOPHARMACOLOGICAL RELEVANCE

The Yunpi-Xiefei-Huatan decoction (YXHD) is a traditional Chinese medicine that can improve asthma-related symptoms, including cough, phlegm in the throat, and shortness of breath. However, the YXHD mechanism on asthma has not yet been elucidated.

STUDY AIM

The aim of this study is to investigate the effect of YXHD on airway inflammation, mucus hypersecretion, and autophagy modulation in asthma.

MATERIALS AND METHODS

The YXHD chemical constituents were observed and analyzed using high-performance liquid chromatography-mass spectrometry. Ovalbumin sensitization and stimulation were used to establish an asthma rat model. A total of 80 Sprague-Dawley (SD) rats were segmented into eight groups at random: a Normal (NC) group, a Model (Mod) group, a YXHD low-dose group (10 g/kg/d), a YXHD moderate-dose group (20 g/kg/d), a YXHD high-dose group (40 g/kg/d), a Rapamycin group (4 mg/kg/d), a 3-methyladenine (3-MA) group (15 mg/kg/d), and a Dexamethasone (DEX) group (0.5 mg/kg/d). Whole-body plethysmography (WBP) detection was used to evaluate airway hyperresponsiveness. An enzyme-linked immunosorbent assay (ELISA) was used to detect inflammatory factors in the peripheral blood. Inflammatory cells in the bronchoalveolar lavage fluid (BALF) were also counted. Pathological changes in the lung tissues were marked using hematoxylin and eosin (H&E) staining and periodic acid-Schiff (PAS) staining. The localization of MUC5AC and the co-localization of LC3B + MUC5AC were observed using immunofluorescence. The expressions of autophagy and the TGF-β3/Smad2/Smad3 pathway in the lung tissues were detected using a Western blot assay (WB) and qPCR, and the autophagosomes in the lung tissues were detected using a transmission electron microscope (TEM).

RESULTS

Twenty signal peaks were identified using ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) technology. The TGF-β3/Smad2/Smad3 signal pathway activation was induced using ovalbumin (OVA) exposure in the rats. The upregulated expression of autophagy, enhanced MUC5AC fluorescence and LC3B fluorescence, and their co-localized expression in the airway epithelium indicated inflammatory cell infiltration and excessive mucus secretion in the lungs. This resulted in airway hyper-responsiveness. The YXHD inhibited the activation of the TGF-β3/Smad2/Smad3 signaling pathway, and autophagy expression reduced inflammatory factors, abnormal mucus secretion, and airway hyperresponsiveness.

CONCLUSION

The YXHD improved lung function, relieved lung inflammation, and inhibited airway mucus secretions in asthmatic rat models. Its mechanism may have been related to the blockage of the TGF-β3/Smad2/Smad3 signaling pathway and autophagy downregulation.

miR-184, a downregulated ovary-elevated miRNA transcriptionally activated by SREBF2, exerts anti-apoptotic properties in ovarian granulosa cells through inducing SMAD3 expression

Follicular atresia is the primary threat to female fertility. miRNAs are dysregulated in granulosa cells (GCs) during follicular atresia, and have emerged as crucial regulators of the initiation and progression of follicular atresia. However, the downregulated ovary-elevated (OE) miRNAs and their biological functions in ovary remain elusive. Here, 13 downregulated OE miRNAs were systematically identified by integrating tissue expression high-throughput data and comparative transcriptome analyses, among which miR-184 was specifically highly expressed in ovary but dramatically downregulated during follicular atresia. Low miR-184 levels were also positively correlated with follicular atresia. Based on the in vitro GC and follicle culture system, we found that miR-184 suppressed GC apoptosis and follicular atresia. Mechanistically, miR-184 induced SMAD3 transcription by acting as a saRNA, and also stabilized SMAD3 mRNA by directly binding to its 5'-UTR, which promoted TGF-β pathway activity and its anti-apoptotic effect. In addition, miR-184 was transcribed independently of host gene, which was activated by SREBF2 in an H3K4me3-dependent manner. Comparative analysis revealed that SREBF2 expression and H3K4me3 enrichment on miR-184 promoter in GCs from atretic follicles were dramatically reduced, which leads to the downregulation of miR-184 during follicular atresia. Moreover, the expression pattern, function, target, and regulatory mechanism of miR-184 among mammals are highly conserved and universal. Taken together, our findings demonstrate that miR-184, transcriptionally activated by SREBF2 in an H3K4me3-dependent manner, exerts anti-atretic effects by inducing SMAD3 expression, highlighting that it is a promising regulator for improving follicular development, ovarian health and female fertility.

Regulation of corneal epithelial differentiation: miR-141-3p promotes the arrest of cell proliferation and enhances the expression of terminal phenotype

In recent years, different laboratories have provided evidence on the role of miRNAs in regulation of corneal epithelial metabolism, permeability and wound healing, as well as their alteration after surgery and in some ocular pathologies. We searched the available databases reporting miRNA expression in the human eye, looking for miRNAs highly expressed in central cornea, which could be crucial for maintenance of the epithelial phenotype. Using the rabbit RCE1(5T5) cell line as a model of corneal epithelial differentiation, we describe the participation of miR-141-3p as a possible negative regulator of the proliferative/migratory phenotype in corneal epithelial cells. The expression of miR-141-3p followed a time course similar to the differentiation-linked KRT3 cytokeratin, being delayed 24-48 hours relative to PAX6 expression; such result suggested that miR-141-3p only regulates the expression of terminal phenotype. Inhibition of miR-141-3p led to increased cell proliferation and motility, and induced the expression of molecular makers characteristic of an Epithelial Mesenchymal Transition (EMT). Comparison between the transcriptional profile of cells in which miR-141-3p was knocked down, and the transcriptomes from proliferative non-differentiated and differentiated stratified epithelia suggest that miR-141-3p is involved in the expression of terminal differentiation mediating the arrest of cell proliferation and inhibiting the EMT in highly motile early differentiating cells.

The forecasting power of the mucin-microbiome interplay in livestock respiratory diseases

Complex respiratory diseases are a significant challenge for the livestock industry worldwide. These diseases considerably impact animal health and welfare and cause severe economic losses. One of the first lines of pathogen defense combines the respiratory tract mucus, a highly viscous material primarily composed of mucins, and a thriving multi-kingdom microbial ecosystem. The microbiome-mucin interplay protects from unwanted substances and organisms, but its dysfunction may enable pathogenic infections and the onset of respiratory disease. Emerging evidence also shows that noncoding regulatory RNAs might modulate the structure and function of the microbiome-mucin relationship. This opinion paper unearths the current understanding of the triangular relationship between mucins, the microbiome, and noncoding RNAs in the context of respiratory infections in animals of veterinary interest. There is a need to look at these molecular underpinnings that dictate distinct health and disease outcomes to implement effective prevention, surveillance, and timely intervention strategies tailored to the different epidemiological contexts.

Mechanisms of Mt.b Ag85B-Fc fusion protein against allergic asthma in mice by intranasal immunization

Ag85B, the primary component of the Ag85 complex and an early secreted protein by Mycobacterium tuberculosis, has shown potential for the treatment of allergic asthma (AA) when used as a Fc-fusion protein. Administered via nasal immunization, Ag85B-Fc fusion protein significantly alleviated airway inflammation and reduced the proportions of some anaphylaxis related cells in lungs, with no significant histopathological injury to major organs in ovalbumin (OVA)-induced AA model mice. To investigate the underlying immune regulatory mechanisms of Ag85B protein, integrated proteomics and transcriptomics analyses were conducted, identifying the complement and coagulation cascades, and phagosomes as the two significantly enriched pathways at both gene and protein levels. Moreover, C3ar1 (C3aR1), Itgam (CD11b), Itgb2 (CD18), fgg (FGG), Cybb (CYBB), and Ncf4 (NCF4) were identified as core target factors that play a central role in allergic and asthmatic responses. Among them, C3aR1 and CR3 consisting of CD11b and CD18, are main complement receptors, indicating that Ag85B alleviated AA by regulating C3aR1- and CR3-mediated signal transduction. The validation results were consistent with the aforementioned findings. Overall, these results provide valuable insight into the application of mucosal immunotherapy in treatment of AA, positioning Ag85B-Fc fusion protein as a safe mucosal immunotherapeutic agent for AA.

IL-13 induces loss of CFTR in ionocytes and reduces airway epithelial fluid absorption

The airway surface liquid (ASL) plays a crucial role in lung defense mechanisms, and its composition and volume are regulated by the airway epithelium. The cystic fibrosis transmembrane conductance regulator (CFTR) is abundantly expressed in a rare airway epithelial cell type called an ionocyte. Recently, we demonstrated that ionocytes can increase liquid absorption through apical CFTR and basolateral barttin/chloride channels, while airway secretory cells mediate liquid secretion through apical CFTR channels and basolateral NKCC1 transporters. Th2-driven (IL-4/IL-13) airway diseases, such as asthma, cause goblet cell metaplasia, accompanied by increased mucus production and airway secretions. In this study, we investigate the effect of IL-13 on chloride and liquid transport performed by ionocytes. IL-13 treatment of human airway epithelia was associated with reduced epithelial liquid absorption rates and increased ASL volume. Additionally, IL-13 treatment reduced the abundance of CFTR-positive ionocytes and increased the abundance of CFTR-positive secretory cells. Increasing ionocyte abundance attenuated liquid secretion caused by IL-13. Finally, CFTR-positive ionocytes were less common in asthma and chronic obstructive pulmonary disease and were associated with airflow obstruction. Our findings suggest that loss of CFTR in ionocytes contributes to the liquid secretion observed in IL-13-mediated airway diseases.

Exploring the causal relationship between the immune cell-inflammatory factor axis and lung cancer: a Mendelian randomization study

Background

Lung cancer is a major health burden globally and smoking is a well-known risk factor. It has been observed that chronic inflammation contributes to lung cancer progression, with immune cells and inflammatory cytokines implicated in tumor development. Clarifying the causal links between these immune components and lung cancer could enhance prevention and therapy.

Methods

We performed Mendelian randomization (MR) to explore causal connections between immune cells, inflammatory markers, and lung cancer risk, using genetic variants as instruments. Data from GWAS on these variables underpinned our MR analyses.

Results

Our findings indicated an inverse association between some immune cells and lung cancer risk, implying that more immune cells might be protective. NK T cells (CD16-CD56) and myeloid cells (HLA DR+ on CD33dim HLA DR+ CD11b+) had an inverse correlation with lung cancer risk. Furthermore, a direct relationship was observed between inflammatory cytokines and these immune cells. In contrast, IL-18 was inversely associated with lung cancer, while IL-13 showed a direct correlation.

Conclusion

The study underscores the role of immune and inflammatory factors in lung cancer. These insights could lead to new therapeutic strategies for combating lung cancer.

Serum exosomal miR-141-3p and miR-3679-5p levels associated with endotype and postoperative recurrence in chronic rhinosinusitis with nasal polyps

Background

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory disease. Exosomes were involved in different inflammatory diseases, but their roles in CRSwNP were poorly explored.

Method

We collected serum samples from 8 CRSwNP patients and 8 healthy controls (HC) and isolated their exosomes. MiRNA sequencing was performed for the exosome samples and differentially expressed miRNAs were identified. The top 3 differentially expressed exosomal miRNAs were confirmed in 2 validation cohorts, and their diagnostic values, predictive values for eosinophilic endotype, and recurrence were evaluated.

Results

Distinctive serum exosomal miRNA profiles were observed between CRSwNP and HC groups. Reverse transcription-polymerase chain reaction results in the first validation cohort revealed that serum exosomal miR-141-3p levels were increased, and miR-18a-5p and miR-3679-5p levels were decreased in the CRSwNP group compared to the HC group. These 3 miRNAs were further validated in the second validation cohort, and the results showed that miR-141-3p levels were elevated and miR-3679-5p levels were reduced in the serum exosomes in the eosinophilic CRSwNP group in comparison with the non-eosinophilic CRSwNP group. Receiver operating characteristic (ROC) curves highlighted that exosomal miR-141-3p and miR-3679-5p exhibited promising values for predicting the eosinophilic endotype. The patients in the second cohort were followed up for 2 years, and categorized into recurrence and non-recurrence groups. The serum exosomal miR-141-3p levels were increased and miR-3679-5p levels were reduced in the recurrence group in comparison with the non-recurrence group. ROC curves and Kaplan-Meier survival analysis revealed significant associations between the levels of exosomal miR-141-3p and miR-3679-5p and the risk of postoperative recurrence.

Conclusions

This study identified unique miRNA expression patterns in serum exosomes of CRSwNP patients. Circulating exosomal miR-141-3p and miR-3679-5p emerged as novel biomarkers for diagnosing CRSwNP, predicting the eosinophilic endotype, and forecasting postoperative recurrence.

Impaired tryptophan metabolism by type 2 inflammation in epithelium worsening asthma

Previous researches indicate that tryptophan metabolism is critical to allergic inflammation and that indoleamine 2,3-dioxygenase 1 (IDO1), as a key enzyme, is known for its immunosuppressive properties. Therefore, we are aimed to explore whether tryptophan metabolism, especially IDO1, influences allergic asthma and clarify specific mechanism. With the analysis of clinical data, exploration in cell experiments, and verifying in HDM-induced asthma mice models, we finally found that in allergic asthma, low level of T1 cytokines along with high level of T2 cytokines inhibited the expression of IDO1 in airway epithelium, hampering the kynurenine pathway in tryptophan metabolism and decreasing the level of intracellular kynurenine (Kyn). As an endogenous ligand of aryl hydrocarbon receptor, Kyn regulated the expression of cystathionine-γ-lyase (CTH). Notably, in asthma models, enhancing either IDO1 or H2S relieved asthma, while inhibiting the activity of CTH exacerbated it. IDO1-Kyn-CTH pathway could be a potential target for treatment for allergic asthma.

Comprehensive review for non-coding RNAs: From mechanisms to therapeutic applications

Non-coding RNAs (ncRNAs) are an assorted collection of transcripts that are not translated into proteins. Since their discovery, ncRNAs have gained prominence as crucial regulators of various biological functions across diverse cell types and tissues, and their abnormal functioning has been implicated in disease. Notably, extensive research has focused on the relationship between microRNAs (miRNAs) and human cancers, although other types of ncRNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), are also emerging as significant contributors to human disease. In this review, we provide a comprehensive summary of our current knowledge regarding the roles of miRNAs, lncRNAs, and circRNAs in cancer and other major human diseases, particularly cancer, cardiovascular, neurological, and infectious diseases. Moreover, we discuss the potential utilization of ncRNAs as disease biomarkers and as targets for therapeutic interventions.

TCF1-LEF1 co-expression identifies a multipotent progenitor cell (TH2-MPP) across human allergic diseases

Repetitive exposure to antigen in chronic infection and cancer drives T cell exhaustion, limiting adaptive immunity. In contrast, aberrant, sustained T cell responses can persist over decades in human allergic disease. To understand these divergent outcomes, we employed bioinformatic, immunophenotyping and functional approaches with human diseased tissues, identifying an abundant population of type 2 helper T (TH2) cells with co-expression of TCF7 and LEF1, and features of chronic activation. These cells, which we termed TH2-multipotent progenitors (TH2-MPP) could self-renew and differentiate into cytokine-producing effector cells, regulatory T (Treg) cells and follicular helper T (TFH) cells. Single-cell T-cell-receptor lineage tracing confirmed lineage relationships between TH2-MPP, TH2 effectors, Treg cells and TFH cells. TH2-MPP persisted despite in vivo IL-4 receptor blockade, while thymic stromal lymphopoietin (TSLP) drove selective expansion of progenitor cells and rendered them insensitive to glucocorticoid-induced apoptosis in vitro. Together, our data identify TH2-MPP as an aberrant T cell population with the potential to sustain type 2 inflammation and support the paradigm that chronic T cell responses can be coordinated over time by progenitor cells.

Advances in co-pathogenesis of the united airway diseases

According to the concept of "united airway diseases", the airway is a single organ in which upper and lower airway diseases are commonly comorbid. A range of inflammatory factors have been found to play an important role in the chain reaction of upper and lower airway diseases. However, the amount of research on this concept remains limited. The underlying mechanism of the relationship between typical diseases of the united airway, such as asthma, allergic rhinitis, and chronic sinusitis, also needs to be further explored. This review highlights the interaction between upper and lower respiratory diseases gathered from epidemiological, histoembryology, neural mechanistic, microbiological, and clinical studies, revealing the relationship between the upper and lower respiratory tracts.

A novel piwi-interacting RNA associates with type 2-high asthma phenotypes

BACKGROUND

Piwi-interacting RNAs (piRNAs), comprising the largest noncoding RNA group, regulate transcriptional processes. Whether piRNAs are associated with type 2 (T2)-high asthma is unknown.

OBJECTIVE

We sought to investigate the association between piRNAs and T2-high asthma in childhood asthma.

METHODS

We sequenced plasma samples from 462 subjects in the Childhood Asthma Management Program (CAMP) as the discovery cohort and 1165 subjects in the Genetics of Asthma in Costa Rica Study (GACRS) as a replication cohort. Sequencing reads were filtered first, and piRNA reads were annotated and normalized. Linear regression was used for the association analysis of piRNAs and peripheral blood eosinophil count, total serum IgE level, and long-term asthma exacerbation in children with asthma. Mediation analysis was performed to investigate the effect direction. We then ascertained if the circulating piRNAs were present in asthmatic airway epithelial cells in a Gene Expression Omnibus (GEO; www.ncbi.nlm.nih.gov/geo) public data set.

RESULTS

Fifteen piRNAs were significantly associated with eosinophil count in CAMP (P ≤ .05), and 3 were successfully replicated in GACRS. Eleven piRNAs were associated with total IgE in CAMP, and one of these was replicated in GACRS. All 22 significant piRNAs were identified in epithelial cells in vitro, and 6 of these were differentially expressed between subjects with asthma and healthy controls. Fourteen piRNAs were associated with long-term asthma exacerbation, and effect of piRNAs on long-term asthma exacerbation are mediated through eosinophil count and serum IgE level.

CONCLUSION

piRNAs are associated with peripheral blood eosinophils and total serum IgE in childhood asthma and may play important roles in T2-high asthma.

Characteristics of mucin hypersecretion in different inflammatory patterns based on endotypes of chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is usually accompanied by mucin hypersecretion that can lead to mucus accumulation and impair nasal mucociliary clearance, thus exacerbating airway inflammation. Abnormal mucin hypersecretion is regulated by different T helper (Th) cytokines, which are associated with different endotype-driven inflammatory responses. Therefore, it is of great significance to understand how these factors regulate mucin hypersecretion to provide precise treatment strategies for different endotypes of CRS. BODY: Thus far, the most common endotypes of CRS are classified as type 1, type 2, or type 3 immune responses based on innate and adaptive cell-mediated effector immunity, and the representative Th cytokines in these immune responses, such as IFN-γ, TNF-α, IL-4, IL-5, IL-13, IL-10, IL-17, and IL-22, play an important regulatory role in mucin secretion. We reviewed all the related literature in the PubMed database to determine the expression of these Th cytokines in CRS and the role they play in the regulation of mucin secretion.

CONCLUSION

We believe that the main Th cytokines involved in specific endotypes of CRS play a key role in regulating abnormal mucin secretion, which contributes to better understanding of the pathogenesis of CRS and provides therapeutic targets for airway inflammatory diseases associated with mucin hypersecretion.

Therapeutic Targets and Precision Medicine in COPD: Inflammation, Ion Channels, Both, or Neither?

The development of a wider range of therapeutic options is a key objective in drug discovery for chronic obstructive pulmonary disease (COPD). Fundamental advances in lung biology have the potential to greatly expand the number of therapeutic targets in COPD. The recently reported successful Phase 3 clinical trial of the first biologic agent for COPD, the monoclonal antibody dupilumab, adds additional support to the importance of targeting inflammatory pathways in COPD. However, numerous other cellular mechanisms are important targets in COPD therapeutics, including airway remodeling, the CFTR ion channel, and mucociliary function. Some of these emerging targets can be exploited by the expanded use of existing COPD drugs, such as roflumilast, while targeting others will require the development of novel molecular entities. The identification of additional therapeutic targets and agents has the potential to greatly expand the value of using clinical and biomarker data to classify COPD into specific subsets, each of which can be predictive of an enhanced response to specific subset(s) of targeted therapies. The author reviews established and emerging drug targets in COPD and uses this as a framework to define a novel classification of COPD based on therapeutic targets. This novel classification has the potential to enhance precision medicine in COPD patient care and to accelerate clinical trials and pre-clinical drug discovery efforts.

The SIRT3 activator ganoderic acid D regulates airway mucin MUC5AC expression via the NRF2/GPX4 pathway

PURPOSE

The expression of MUC5AC, a highly prevalent airway mucin, is regulated by stimulatory factors such as oxidative stress. Ganoderic acid D (GAD) activates mitochondrial deacetylase SIRT3. SIRT3 regulates mitochondrial function through deacetylation of mitochondrial proteins, thereby playing a significant role in alleviating oxidative stress-related diseases. Therefore, this study aimed to investigate the mechanisms and rationale underlying the regulation of MUC5AC expression by GAD.

METHODS

Human airway epithelial cells (NCI-H292) were exposed to pyocyanin (PCN) to establish an in vitro cell model of airway mucus hypersecretion. The expression of SIRT3, MUC5AC, and NRF2 pathway proteins in cells was assessed. Cellular mitochondrial morphology and oxidative stress markers were analyzed. C57BL/6 mice were induced with Pseudomonas aeruginosa (PA) to establish an in vivo mouse model of airway mucus hypersecretion. The expression of SIRT3 and MUC5AC in the airways was examined. In addition, the differential expression of target genes in the airway epithelial tissues of patients with chronic obstructive pulmonary disease (COPD) was analyzed using publicly available databases.

RESULTS

The results revealed a significant upregulation of MUC5AC expression and a significant downregulation of SIRT3 expression in relation to airway mucus hypersecretion. GAD inhibited the overexpression of MUC5AC in PCN-induced NCI-H292 cells and PA-induced mouse airways by upregulating SIRT3. GAD activated the NRF2/GPX4 pathway and inhibited PCN-induced oxidative stress and mitochondrial morphological changes in NCI-H292 cells. However, ML385 inhibited the regulatory effects of GAD on MUC5AC expression.

CONCLUSION

The SIRT3 activator GAD downregulated MUC5AC expression, potentially through activation of the NRF2/GPX4 pathway. Accordingly, GAD may be a potential treatment approach for airway mucus hypersecretions.

Aromadendrin inhibits PMA-induced cytokine formation/NF-κB activation in A549 cells and ovalbumin-induced bronchial inflammation in mice

Hyperproduction of immune cell-derived inflammatory molecules and recruitment of immune cells promote the development of allergic asthma (AA). Aromadendrin (ARO) has various biological properties including anti-inflammatory effects. In this study, we evaluated the ameliorative effects of ARO on the development of AA in vitro and in vivo. Phorbol 12-myristate 13-acetate (PMA, 100 nM) was used to induce inflammation in A549 airway epithelial cells. The cohesion of A549 and eosinophil EOL-1 cells was studied. Ovalbumin (30 or 60 μg)/Alum (3 mg) mixture was adapted for AA induction in mice. ARO (5 or 10 mg/kg, p. o.) was administered to mice to investigate its ameliorative effect on AA development. Enzyme-linked immunosorbent assay, western blotting, and hematoxylin and eosin/periodic acid Schiff staining were performed to study the ameliorative effect of ARO on bronchial inflammation. In PMA-stimulated A549 cells, the upregulation of cytokines (interleukin [IL]-1β/IL-6/tumor necrosis factor alpha [TNF-α]/monocyte chemoattractant protein [MCP]-1]) and nuclear factor kappa B (NF-κB) activation was effectively reduced by ARO pretreatment. ARO suppressed the adhesion of A549 cells and eosinophils. In ovalbumin-induced AA mice, the levels of cells, such as eosinophils, Th2 cytokines, MCP-1 in bronchoalveolar lavage fluid, IgE in serum, and inducible nitric oxide synthase/cyclooxygenase-2 expression in the lung tissue were upregulated, which were all suppressed by ARO. In addition, the increase in cell inflow and mucus formation in the lungs of AA mice was reversed by ARO as per histological analysis. ARO also modulated NF-κB activation in the lungs of AA mice. Overall, the anti-inflammatory properties of ARO in vitro/in vivo studies of AA were notable. Thus, ARO has a modulatory effect on bronchial inflammation and may be a potential adjuvant for AA treatment.

Recent advances in understanding the effects of T lymphocytes on mucosal barrier function in allergic rhinitis

Allergic rhinitis is a non-infectious chronic inflammatory disease of the nasal mucosa that affects T cells and their cytokines. T cells play significant roles in the development of allergic inflammatory diseases by orchestrating mechanisms underlying innate and adaptive immunity. Although many studies on allergic rhinitis have focused on helper T cells, molecular makeup, and pathogenesis-related transduction pathways, pathological mechanisms have not yet been completely explored. Recent studies have suggested that T cell status may play an important role in the interaction between T cells and the nasal mucosal barrier in allergic rhinitis. This study aimed to explore the interactions between T cells and nasal mucosal barriers in allergic rhinitis and to review the therapeutic modalities of pertinent biological agents involving T cells.

Interactions between circRNAs and miR-141 in Cancer: From Pathogenesis to Diagnosis and Therapy

The function of non-coding RNAs (ncRNAs) in the pathogenesis and development of cancer is indisputable. Molecular mechanisms underlying carcinogenesis involve the aberrant expression of ncRNAs, including circular RNAs (circRNAs), and microRNAs (miRNAs). CircRNAs are a class of single-stranded, covalently closed RNAs responsible for maintaining cellular homeostasis through their diverse functions. As a part of the competing endogenous RNA (ceRNAs) network, they play a central role in the regulation of accessibility of miRNAs to their mRNA targets. The interplay between these molecular players is based on the primary role of circRNAs that act as miRNAs sponges, and the circRNA/miRNA imbalance plays a central role in different pathologies including cancer. Herein, we present the latest state of knowledge about interactions between circRNAs and miR-141, a well-known member of the miR-200 family, in malignant transformation, with emphasis on the biological role of circRNA/miR-141/mRNA networks as a future target for novel anti-cancer therapies.

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.

Air-Liquid interface cultures to model drug delivery through the mucociliary epithelial barrier

Epithelial cells from mucociliary portions of the airways can be readily grown and expanded in vitro. When grown on a porous membrane at an air-liquid interface (ALI) the cells form a confluent, electrically resistive barrier separating the apical and basolateral compartments. ALI cultures replicate key morphological, molecular and functional features of the in vivo epithelium, including mucus secretion and mucociliary transport. Apical secretions contain secreted gel-forming mucins, shed cell-associated tethered mucins, and hundreds of additional molecules involved in host defense and homeostasis. The respiratory epithelial cell ALI model is a time-proven workhorse that has been employed in various studies elucidating the structure and function of the mucociliary apparatus and disease pathogenesis. It serves as a critical milestone test for small molecule and genetic therapies targeting airway diseases. To fully exploit the potential of this important tool, numerous technical variables must be thoughtfully considered and carefully executed.

Inhaled drug delivery for the targeted treatment of asthma

Asthma is a chronic lung disease affecting millions worldwide. While classically acknowledged to result from allergen-driven type 2 inflammatory responses leading to IgE and cytokine production and the influx of immune cells such as mast cells and eosinophils, the wide range in asthmatic pathobiological subtypes lead to highly variable responses to anti-inflammatory therapies. Thus, there is a need to develop patient-specific therapies capable of addressing the full spectrum of asthmatic lung disease. Moreover, delivery of targeted treatments for asthma directly to the lung may help to maximize therapeutic benefit, but challenges remain in design of effective formulations for the inhaled route. In this review, we discuss the current understanding of asthmatic disease progression as well as genetic and epigenetic disease modifiers associated with asthma severity and exacerbation of disease. We also overview the limitations of clinically available treatments for asthma and discuss pre-clinical models of asthma used to evaluate new therapies. Based on the shortcomings of existing treatments, we highlight recent advances and new approaches to treat asthma via inhalation for monoclonal antibody delivery, mucolytic therapy to target airway mucus hypersecretion and gene therapies to address underlying drivers of disease. Finally, we conclude with discussion on the prospects for an inhaled vaccine to prevent asthma.

Recent miRNA Research in Asthma

PURPOSE OF REVIEW

The study of microRNA in asthma has revealed a vibrant new level of gene regulation underlying asthma pathology. Several miRNAs have been shown to be important in asthma, influencing various biological mechanisms which lead to asthma pathology and symptoms. In addition, miRNAs have been proposed as biomarkers of asthma affection status, asthma severity, and asthma treatment response. We review all recent asthma-miRNA work, while also presenting comprehensive tables of all miRNA results related to asthma.

RECENT FINDINGS

We here reviewed 63 recent studies published reporting asthma and miRNA research, and an additional 14 reviews of the same. We summarized the information for both adult and childhood asthma, as well as research on miRNAs in asthma-COPD overlap syndrome (ACOs), and virus-induced asthma exacerbations. We attempted to present a comprehensive collection of recently published asthma-associated miRNAs as well as tables of all published asthma-related miRNA results.

Single-cell RNA-sequencing in asthma research

Asthma is a complex and heterogeneous disease with multicellular involvement, and knowledge gaps remain in our understanding of the pathogenesis of asthma. Efforts are still being made to investigate the immune pathogenesis of asthma in order to identify possible targets for prevention. Single cell RNA sequencing (scRNA-seq) technology is a useful tool for exploring heterogeneous diseases, identifying rare cell types and distinct cell subsets, enabling elucidation of key processes of cell differentiation, and understanding regulatory gene networks that predict immune function. In this article, we provide an overview of the importance of scRNA-seq for asthma research, followed by an in-depth discussion of the results in recent years, in order to provide new ideas for the pathogenesis, drug development and treatment of asthma.

Role of airway epithelial cell miRNAs in asthma

The airway epithelial cells and overlying layer of mucus are the first point of contact for particles entering the lung. The severity of environmental contributions to pulmonary disease initiation, progression, and exacerbation is largely determined by engagement with the airway epithelium. Despite the cellular cross-talk and cargo exchange in the microenvironment, epithelial cells produce miRNAs associated with the regulation of airway features in asthma. In line with this, there is evidence indicating miRNA alterations related to their multifunctional regulation of asthma features in the conducting airways. In this review, we discuss the cellular components and functions of the airway epithelium in asthma, miRNAs derived from epithelial cells in disease pathogenesis, and the cellular exchange of miRNA-bearing cargo in the airways.

Role of microRNAs in type 2 diseases and allergen-specific immunotherapy

MicroRNAs (miRs) have gained scientific attention due to their importance in the pathophysiology of allergic diseases as well as their potential as biomarkers in allergen-specific treatment options. Their function as post-transcriptional regulators, controlling various cellular processes, is of high importance since any single miR can target multiple mRNAs, often within the same signalling pathway. MiRs can alter dysregulated expression of certain cellular responses and contribute to or cause, but in some cases prevent or repress, the development of various diseases. In this review article, we describe current research on the role of specific miRs in regulating immune responses in epithelial cells and specialized immune cells in response to various stimuli, in allergic diseases, and regulation in the therapeutic approach of allergen-specific immunotherapy (AIT). Despite the fact that AIT has been used successfully as a causative treatment option since more than a century, very little is known about the mechanisms of regulation and its connections with microRNAs. In order to fill this gap, this review aims to provide an overview of the current knowledge.

Oxysophocarpine inhibits airway inflammation and mucus hypersecretion through JNK/AP-1 pathway in vivo and in vitro

Asthma is a high-incidence disease in the world. Oxysophocarpine (OSC), a quinolizidine alkaloid displays various pharmacological functions including anti-inflammation, neuroprotective, anti-virus and antioxidant. Here, we established mice and cell asthmatic model to explore the effects of OSC for asthma treatment. Mice were sensitized and challenged with ovalbumin (OVA) and treated with OSC before challenge. Enzyme-linked immuno sorbent assay (ELISA), hematoxylin and eosin (H&E), periodic acid-schiff (PAS), tolonium chloride staining and immunohistochemical assay were performed. OSC treatment inhibited inflammatory cell infiltration and mucus secretion in the airway, reduced IgE level in mouse serum and decreased IL-4, IL-5 production in bronchoalveolar lavage fluid (BALF). OSC also reduced the spleen index to regulate immune function. Meanwhile, NCI-H292 cells were induced by lipopolysaccharide (LPS) to simulate airway epithelial injury. OSC pretreatment decreased the IL-6 and IL-8 cytokine levels, mucin 5 AC expression, and mucin 5 AC mRNA level in the cell model. Further, OSC suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), and activator protein 1 (AP-1, Fos and Jun). These findings revealed that OSC alleviated bronchial asthma associated with JNK/AP-1 signaling pathway.

Role of ILC2s in Solid Tumors: Facilitate or Inhibit?

Group 2 innate lymphoid cells (ILC2s) are important mediators of type 2 immunity and play an important role in allergic diseases, helminth infections, and tissue fibrosis. However, the role of ILC2s in tumor immunity requires further elucidation. Studies over the past decade have reported that ILC2s play a promoting or suppressing role in different tumors. Here we reviewed the role of ILC2s in solid tumors demonstrating that ILC2s act as a crucial regulator in tumor immunity. We proposed that ILC2s could be an important predictor for tumor prognosis and a new therapeutic target after immunotherapy resistance. In conclusion, our study shed new light on modifying and targeting ILC2s for anti-tumor immunotherapy.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

Therapeutic Strategies of Biologics in Chronic Rhinosinusitis: Current Options and Future Targets

Chronic rhinosinusitis is a chronic inflammatory disease of the upper airways, for which treatment options include medical or surgical therapy. However, there are limitations to conservative treatment strategies, such as the relapse of nasal polyps. In this review, we discuss the rising role of biomolecular mechanisms associated with various biologics that have been approved or are undergoing clinical trials to treat chronic rhinosinusitis. We also highlight the potential molecular therapeutic targets for managing and treating chronic rhinosinusitis.

Meteorin-β/Meteorin like/IL-41 attenuates airway inflammation in house dust mite-induced allergic asthma

We sought to examine the regulatory effect of Meteorin-β (Metrnβ)/Meteorin like (Metrnl)/IL-41 on lung inflammation in allergic asthma. We found that Metrnβ was elevated significantly in asthmatic patients and in mice with allergic asthma induced by house dust mite (HDM) extract. Upon exposure to HDM, Metrnβ was secreted predominantly by airway epithelial cells and inflammatory cells, including macrophages and eosinophils. The increased Metrnβ effectively blocked the development of airway hyperreactivity (AHR) and decreased inflammatory cell airway infiltration and type 2 cytokine production, which was associated with downregulated DC-mediated adaptive immune responses. Moreover, Metrnβ impaired the maturation and function of bone marrow-derived dendritic cells in vitro. Asthmatic mice adoptively transferred with dendritic cells isolated from Metrnβ-treated allergic mice displayed decreased AHR, airway inflammation, and lung injury. Metrnβ also displayed anti-inflammatory properties in immunodeficient SCID mice with allergic asthma and in in vitro 3D ALI airway models. Moreover, blockade of Metrnβ by anti-Metrnβ antibody treatment promoted the development of allergic asthma. These results revealed the unappreciated protective roles of Metrnβ in alleviating DC-mediated Th2 inflammation in allergic asthma, providing the novel treatment strategy of therapeutic targeting of Metrnβ in allergic asthma.

Epithelial microRNA-30a-3p targets RUNX2/HMGB1 axis to suppress airway eosinophilic inflammation in asthma

Background

Type 2-high asthma is a prominent endotype of asthma which is characterized by airway eosinophilic inflammation. Airway epithelial cells play a critical role in the pathogenesis of asthma. Our previous miRNA profiling data showed that miR-30a-3p was downregulated in bronchial epithelial cells from asthma patients. We hypothesize that epithelial miR-30a-3p plays a role in asthma airway inflammation.

Methods

We measured miR‐30a-3p expression in bronchial brushings of asthma patients (n = 51) and healthy controls (n = 16), and analyzed the correlations between miR‐30a-3p expression and airway eosinophilia. We examined whether Runt-related transcription factor 2 (RUNX2) was a target of miR‐30a-3p and whether RUNX2 bound to the promoter of high mobility group box 1 (HMGB1) by using luciferase reporter assay and chromatin immunoprecipitation (ChIP)-PCR. The role of miR‐30a-3p was also investigated in a murine model of allergic airway inflammation.

Results

We found that miR-30a-3p expression were significantly decreased in bronchial brushings of asthma patients compared to control subjects. Epithelial miR-30a-3p expression was negatively correlated with parameters reflecting airway eosinophilia including eosinophils in induced sputum and bronchial biopsies, and fraction of exhaled nitric oxide in asthma patients. We verified that RUNX2 is a target of miR-30a-3p. Furthermore, RUNX2 bound to the promoter of HMGB1 and upregulated HMGB1 expression. RUNX2 and HMGB1 expression was both enhanced in airway epithelium and was correlated with each other in asthma patients. Inhibition of miR-30a-3p enhanced RUNX2 and HMGB1 expression, and RUNX2 overexpression upregulated HMGB1 in BEAS-2B cells. Intriguingly, airway overexpression of mmu-miR-30a-3p suppressed Runx2 and Hmgb1 expression, and alleviated airway eosinophilia in a mouse model of allergic airway inflammation.

Conclusions

Epithelial miR-30a-3p could possibly target RUNX2/HMGB1 axis to suppress airway eosinophilia in asthma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01933-x.

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.

Epithelial Aryl Hydrocarbon Receptor Protects From Mucus Production by Inhibiting ROS-Triggered NLRP3 Inflammasome in Asthma

Background

Despite long-standing recognition in the significance of mucus overproduction in asthma, its etiology remains poorly understood. Muc5ac is a secretory mucin that has been associated with reduced pulmonary function and asthma exacerbations.

Objectives

We sought to investigate the immunological pathway that controls Muc5ac expression and allergic airway inflammation in asthma.

Methods

Cockroach allergen-induced Muc5ac expression and aryl hydrocarbon receptor (AhR) signaling activation was examined in the human bronchial epithelial cells (HBECs) and mouse model of asthma. AhR regulation of Muc5ac expression, mitochondrial ROS (Mito-ROS) generation, and NLRP3 inflammasome was determined by AhR knockdown, the antagonist CH223191, and AhR-/- mice. The role of NLRP3 inflammasome in Muc5ac expression and airway inflammation was also investigated.

Results

Cockroach allergen induced Muc5ac overexpression in HBECs and airways of asthma mouse model. Increased expression of AhR and its downstream genes CYP1A1 and CYP1B1 was also observed. Mice with AhR deletion showed increased allergic airway inflammation and MUC5AC expression. Moreover, cockroach allergen induced epithelial NLRP3 inflammasome activation (e.g., NLRP3, Caspase-1, and IL-1β), which was enhanced by AhR knockdown or the antagonist CH223191. Furthermore, AhR deletion in HBECs led to enhanced ROS generation, particularly Mito-ROS, and inhibition of ROS or Mito-ROS subsequently suppressed the inflammasome activation. Importantly, inhibition of the inflammasome with MCC950, a NLRP3-specifc inhibitor, attenuated allergic airway inflammation and Muc5ac expression. IL-1β generated by the activated inflammasomes mediated cockroach allergen-induced Muc5ac expression in HBECs.

Conclusions

These results reveal a previously unidentified functional axis of AhR-ROS-NLRP3 inflammasome in regulating Muc5ac expression and airway inflammation.