Increased Expression of miR-146a in Children With Allergic Rhinitis After Allergen-Specific Immunotherapy

MicroRNA expression and their molecular targets in food allergies: a systematic review

Introduction

MicroRNAs (miRs) play an essential role in adaptive and innate immune systems by regulating the development of immune cells. However, detailed studies of miRs' role in food allergies are scarce compared to those of other allergic or non- allergic diseases. This systematic review aims to study miRs expression and its role in food allergies (FAs) and determine the signature miRs in FAs.

Method

Research articles published since 2015 were selected from various databases: Scopus, PubMed, ScienceDirect, and Web of Science. Randomized clinical trials, observational clinical studies, and in vivo studies were assessed via the Cochrane Risk of Bias 2 tool, the Newcastle-Ottawa scale, and SYRCLE method, respectively. The characteristics of the included studies, population characteristics, and experimental details were extracted, and the data were synthesized narratively.

Result

MiRs expression had been investigated in the context of cow milk allergy (CMA) and peanut allergy (PA) through both in vivo studies and clinical trials. Clinical trials included allergies to multiple combined foods, individual foods (such as milk, peanut, and what), and drugs and venom, while in vivo studies were conducted on milk, egg, and peanut allergies. MiR-146a, miR- 155, and miR-30a-5p were common miRs between in vivo studies and clinical trials. Moreover, few miRs were commonly studied between different types of food allergies. In clinical trials, miR-143-3p was studied in peanut allergy and non-celiac wheat sensitivity (NCWS), and miR-155 was studied in CMA and egg allergy in in vivo studies. Furthermore, the same miRs varied on their molecular target and effect depending on the type of food allergy.

Discussion

The study on signature miRs and their molecular target determination for the therapeutic purpose of food allergy is in its initial stage. For individual food allergies, miRs determination via next-generation sequencing (NGS), their validation via polymerase chain reaction (PCR), and target molecule determination via RNA interference (RNAi) should be the focus of future studies in order to determine reliable signature miRs of food allergy.

The role of microRNAs in atopic dermatitis

Atopic dermatitis (AD), known as eczema, is a chronic inflammatory skin condition affecting millions worldwide. This abstract provides an overview of the clinical features and underlying pathogenesis of AD, highlighting the role of specific microRNAs (miRNAs) in its development and progression. AD presents with distinct clinical manifestations that evolve with age, starting in infancy with dry, itchy skin and red patches, which can lead to sleep disturbances. In childhood, the rash spreads to flexural areas, resulting in lichenification. In adulthood, lesions may localize to specific areas, including the hands and eyelids. Pruritus (itchiness) is a hallmark symptom, often leading to excoriations and increased vulnerability to skin infections. The pathogenesis of AD is multifaceted, involving genetic, immunological, and environmental factors. Skin barrier dysfunction, immune dysregulation, genetic predisposition, microbiome alterations, and environmental triggers contribute to its development. Recent research has uncovered the role of miRNAs, such as miR-10a-5p, miR-29b, miR-124, miR-143, miR-146a-5p, miR-151a, miR-155, and miR-223, in AD pathogenesis. These microRNAs play crucial roles in regulating various aspects of immune responses, keratinocyte dynamics, and inflammation. MicroRNA-10a-5p orchestrates keratinocyte proliferation and differentiation, while miR-29b regulates keratinocyte apoptosis and barrier integrity. MicroRNA-124 exhibits anti-inflammatory effects by targeting the NF-κB signaling pathway. MicroRNANA-143 counters allergic inflammation by modulating IL-13 signaling. MicroRNA-146a-5p regulates immune responses and correlates with IgE levels in AD. MicroRNA-151a shows diagnostic potential and modulates IL-12 receptor β2. MicroRNA-155 plays a central role in immune responses and Th17 cell differentiation, offering diagnostic and therapeutic potential. MicroRNA-223 is linked to prenatal smoke exposure and immune modulation in AD. Understanding these microRNAs' intricate roles in AD pathogenesis promises more effective treatments, personalized approaches, and enhanced diagnostic tools. Further research into these molecular orchestrators may transform the landscape of AD management, improving the quality of life for affected individuals.

Advances in noncoding RNA in children allergic rhinitis

BACKGROUND

A chronic condition that significantly reduces a child's quality of life is allergic rhinitis (AR). The environment and allergens that the body is regularly exposed to can cause inflammatory and immunological reactions, which can change the expression of certain genes Epigenetic changes are closely linked to the onset and severity of allergy disorders according to mounting amounts of data. Noncoding RNAs (ncRNAs) are a group of RNA molecules that cannot be converted into polypeptides. The three main categories of ncRNAs include microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs). NcRNAs play a crucial role in controlling gene expression and contribute to the development of numerous human diseases.

METHODS

Articles are selected based on Pubmed's literature review and the author's personal knowledge. The largest and highest quality studies were included. The search selection is not standardized.

RESULTS

Recent findings indicate that various categories of ncRNAs play distinct yet interconnected roles and actively contribute to intricate gene regulatory networks.

CONCLUSION

This article demonstrates the significance and progress of ncRNAs in children's AR. The database covers three key areas: miRNAs, lncRNAs, and circRNAs. Additionally, potential avenues for future research to facilitate the practical application of ncRNAs as therapeutic targets and biomarkers will be explore.

IL-33 Induces Cellular and Exosomal miR-146a Expression as a Feedback Inhibitor of Mast Cell Function

IL-33 is an inflammatory cytokine that promotes allergic disease by activating group 2 innate lymphoid cells, Th2 cells, and mast cells. IL-33 is increased in asthmatics, and its blockade suppresses asthma-like inflammation in mouse models. Homeostatic control of IL-33 signaling is poorly understood. Because the IL-33 receptor, ST2, acts via cascades used by the TLR family, similar feedback mechanisms may exist. MicroRNA (miR)-146a is induced by LPS-mediated TLR4 signaling and serves as a feedback inhibitor. Therefore, we explored whether miR-146a has a role in IL-33 signaling. IL-33 induced cellular and exosomal miR-146a expression in mouse bone marrow-derived mast cells (BMMCs). BMMCs transfected with a miR-146a antagonist or derived from miR-146a knockout mice showed enhanced cytokine expression in response to IL-33, suggesting that miR-146a is a negative regulator of IL-33-ST2 signaling. In vivo, miR-146a expression in plasma exosomes was elevated after i.p. injection of IL-33 in wild-type but not mast cell-deficient KitW-sh/W-sh mice. Finally, KitW-sh/W-sh mice acutely reconstituted with miR-146a knockout BMMCs prior to IL-33 challenge had elevated plasma IL-6 levels compared with littermates receiving wild-type BMMCs. These results support the hypothesis that miR-146a is a feedback regulator of IL-33-mediated mast cell functions associated with allergic disease.

Advancements in Allergen Immunotherapy for the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin condition that affects individuals of all age groups, manifesting as a spectrum of symptoms varying from mild to severe. Allergen immunotherapy (AIT) involves the administration of allergen extracts and has emerged as a potential treatment strategy for modifying immune responses. Its pathogenesis involves epidermal barrier dysfunction, microbiome imbalance, immune dysregulation, and environmental factors. Existing treatment strategies encompass topical steroids to systemic agents, while AIT is under investigation as a potential immune-modifying alternative. Several studies have shown reductions in the severity scoring of atopic dermatitis (SCORAD) scores, daily rescue medication use, and visual analog scale (VAS) scores following AIT. Biomarker changes include increased IgG4 levels and decreased eosinophil counts. This review provides valuable insights for future research and clinical practice, exploring AIT as a viable option for the management of AD.

Efficacy and safety of sublingual versus subcutaneous immunotherapy in children with allergic rhinitis: a systematic review and meta-analysis

Aim

To systematically compare the efficacy and safety of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) in children with allergic rhinitis (AR).

Methods

PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to March 2, 2023. Outcomes included symptom scores (SSs), medication scores (MSs), symptom and medication scores (SMSs), new sensitizations, development of asthma, improvement, and treatment-related adverse events (TRAEs). The quality of the included studies was assessed by the modified Jadad scale and Newcastle-Ottawa scale (NOS). Meta-regression was carried out to explore the source of heterogeneity. Subgroup analysis was further conducted in terms of study design [randomized controlled trials (RCTs), cohort studies], allergen [house dust mites (HDMs), grass pollen], treatment duration (≥ 24, 12-23 or < 12 months), allergen immunotherapy (AIT) modality (drops or tablets), and AIT protocol [continuous, pre-seasonal, co-seasonal, or after the grass pollen season (GPS)]. Sensitivity analysis was conducted for all outcomes. A Bayesian framework and a Monte Carlo Markov Chain (MCMC) model were developed for indirect comparison.

Results

Totally 50 studies with 10813 AR children were included, with 4122 treated with SLIT, 1852 treated with SCIT, and 4839 treated with non-SLIT or non-SCIT therapy. For direct comparison, the SLIT group had a similar SS to the SCIT group [pooled standardized mean difference (SMD): 0.41, 95% confidence interval (CI): -0.46, 1.28, P = 0.353]. Comparable MSs were observed in the SLIT and SCIT groups (pooled SMD: 0.82, 95%CI: -0.88, 2.53, P = 0.344). For indirect comparison, no significant differences were found in SSs (pooled SMD: 1.20, 95% credibility interval (CrI): -1.70, 4.10), MSs (pooled SMD: 0.57, 95%CrI: -1.20, 2.30), SMSs (pooled SMD: 1.80, 95%CrI: -0.005, 3.60), new sensitizations [pooled relative risk (RR): 0.34, 95%CrI: 0.03, 3.58], and development of asthma (pooled RR: 0.68, 95%CrI: 0.01, 26.33) between the SLIT and SCIT groups; the SLIT group illustrated a significantly lower incidence of TRAEs than the SCIT group (pooled RR: 0.17, 95%CrI: 0.11, 0.26).

Conclusion

Considering both efficacy and safety, SLIT might be a more favorable AIT than SCIT in the treatment of pediatric AR, which may serve as a decision-making reference for clinicians.

Systematic review registration

PROSPERO (CRD42023460693).

Protective effects of glaucocalyxin A on the airway of asthmatic mice

The aim of this study is to investigate the protective effects of glaucocalyxin A (GLA) on airways in mouse models of asthma, concerning the inflammatory mediators, Th1/Th2 subgroup imbalance, and Toll-like receptor 4 (TLR4)/NF-κB signaling pathway. Hematoxylin and eosin/periodic acid-Schiff staining was used to observe the pathological changes in lung tissues. Inflammatory cytokine contents in the bronchoalveolar lavage fluid were detected by enzyme-linked immunosorbent assay. Protein expression levels were detected with Western blot, immunohistochemistry, and immunofluorescence. In vivo studies showed that, in ovalbumin (OVA)-induced asthmatic mouse models, the GLA treatments reduced the airway hyperresponsiveness and the secretion of inflammatory cells, declined the proliferation of goblet cells, decreased the levels of IL-4, IL-5, and IL-13, and increased the contents of interferon-γ and IL-12. Moreover, GLA inhibited the protein expression levels of TLR4, MyD88, TRAF6, and NF-κB in OVA-induced asthmatic mouse models. Further in vitro studies showed that GLA inhibited the expression of NF-κB, p-IκBα, tumor necrosis factor-α, IL-6, and IL-1β and blocked the nuclear transfer of NF-κB in lipopolysaccharide-stimulated RAW264.7 macrophages. Conclusively, GLA can inhibit the inflammatory responses in OVA-induced asthmatic mice and inhibit the release of inflammatory factors in LPS-induced RAW264.7 macrophages, which may be related to the inhibition of TLR4/NF-κB signaling pathway.

Prediction of clinical efficacy of subcutaneous immunotherapy for Artemisia sieversiana pollen allergic rhinitis by serum metabolomics

BACKGROUND/PURPOSE

Specific immunotherapy is the only effective etiological treatment for allergic rhinitis, but subcutaneous immunotherapy has a slow onset and poor compliance. Predicting the clinical efficacy of subcutaneous immunotherapy in advance can reduce unnecessary medical costs and resource waste. This study aimed to identify metabolites that could predict the efficacy of subcutaneous immunotherapy on seasonal allergic rhinitis by serum metabolomics.

METHODS

Patients (n = 43) with Artemisia sieversiana pollen allergic rhinitis were enrolled and treated with subcutaneous immunotherapy for one year. Patients were divided into the ineffective group (n = 10) and effective group (n = 33) according to the therapeutic index. Serum samples were collected before treatment. Metabolomics was determined by liquid chromatography-mass spectrometry combined with gas chromatography-mass spectrometry and analyzed differential compounds and related metabolic pathways.

RESULTS

A total of 129 differential metabolites (P < 0.05) were identified and 4 metabolic pathways, namely taurine and hypotaurine metabolism, pentose and glucuronate interconversions, pentose phosphate pathway, and alanine, aspartate, and glutamate metabolism, were involved.

CONCLUSION

Some metabolites, such as hypotaurine, taurine, and l-alanine, have the potential to become predictive biomarkers for effective subcutaneous immunotherapy.

miRNA profiles change during grass pollen immunotherapy irrespective of clinical outcome

Background: Subcutaneous immunotherapy (SCIT) is widely used in the treatment of allergic rhinitis (AR). This study aimed to determine the expression of 48 miRNAs in patients with AR undergoing grass pollen SCIT and investigate relations with clinical outcomes. Methodology: Expression of selected miRNAs was determined using RT-PCR in the full blood of 16 patients with AR and seven healthy controls. Results: miR-136, miR-208 and miR-190 were upregulated in the AR group. After 6 months of SCIT, significant downregulation of some proinflammatory miRNAs and upregulation of several miRNAs regulating Th1/Th2 balance were found. No differences were found between good and poor responders. Conclusion: miRNAs may play a regulatory role in SCIT, leading to tolerance induction.

miR-146a enhances regulatory T-cell differentiation and function in allergic rhinitis by targeting STAT5b

BACKGROUND

MicroRNA (miR)-146a, as an important immune regulatory factor with an anti-inflammatory effect, plays a crucial role in regulatory T-cell (Tregs) differentiation and function in allergic rhinitis (AR). The present study aimed to investigate the regulatory mechanism employed by miR-146a to control Treg differentiation and function in AR.

METHODS

Expression of miR-146a and STAT5b in peripheral blood mononuclear cells (PBMCs) and nasal mucosa from patients with AR was detected by qPCR and Western blotting. Tregs were quantified by flow cytometry in miR-146a knockdown or STAT5b knockdown PBMCs. FOXP3, IL-10, and TGF-β levels were detected by Western blotting or ELISA in miR-146a knockdown or STAT5b overexpressing PBMCs, as well as in STAT5b knockdown PBMCs overexpressing miR-146a. The effect of miR-146a on STAT5b was observed by luciferase assay and knockdown experiments.

RESULTS

Levels of miR146a and STAT5b in the nasal mucosa or PBMCs were significantly lower in the AR group than in the control group. There were significantly fewer Tregs in miR-146a knockdown or STAT5b knockdown PBMCs compared to control PBMCs. Expression of FOXP3, IL-10, and TGF-β was decreased in the miR-146a knockdown group but increased in the STAT5b overexpression group. In contrast, miR-146a overexpression increased the levels of these factors, but knockdown of STAT5b significantly inhibited this effect. Luciferase assay and knockdown experiments showed that miR-146a bound directly to STAT5b.

CONCLUSIONS

miR-146a enhances Treg differentiation and function in AR by positively targeting STAT5b.

Role of microRNAs in inflammatory upper airway diseases

MicroRNAs (miRNAs) are a conserved family of small endogenous noncoding RNA molecules that modulate post-transcriptional gene expression in physiological and pathological processes. miRNAs can silence target mRNAs through degradation or inhibition of translation, showing their pivotal role in the pathogenesis of many human diseases. miRNAs play a role in regulating immune functions and inflammation and are implicated in controlling the development and activation of T and B cells. Inflammatory chronic upper airway diseases, such as rhinitis and rhinosinusitis, are spread all over the world and characterized by an exaggerated inflammation involving a complex interaction between immune and resident cells. Until now and despite allergy, little is known about their etiology and the processes implicated in the immune response and tuning inflammation of these diseases. This review highlights the knowledge of the current literature about miRNAs in inflammatory chronic upper airways diseases and how this may be exploited in the development of new clinical and therapeutic strategies.

MicroRNA-375-mediated regulation of ILC2 cells through TSLP in allergic rhinitis

Background

Studies have shown that the number and function of type II innate lymphoid cells (ILC2) in peripheral blood of allergic rhinitis (AR) children increased significantly. This study aims to evaluate the role of miR-375 in the regulation of the differentiation and function of ILC2 through both in vivo and in vitro studies.

Methods

The expression of miR-375, thymic stromal lymphopoietin (TSLP) and the frequency of ILC2 were detected and compared between AR children and controls by real-time polymerase chain reaction (PCR), enzyme-linked immunosorbnent assay (ELISA) and flow cytometry, respectively. The miR-375 mimics or inhibitors were transfected into human nasal epithelial cells (HNECs), and the production of TSLP was detected by ELISA. HNECs and ILC2s were co-cultured to explore the role of miR-375 on ILC2s. AR mice models were established to prove the effect of miR-375 on ILC2s in vivo.

Results

The expression of TSLP, miR-375, and the frequency of ILC2 were significantly higher in AR compared with controls. We found that the TSLP expression by HNECs were significantly higher when transfected with miR-375 mimics than in those transfected with miR-control and miR-375 inhibitor. In the coculture system, HNECs transfected with miR-375 mimics promote the type II cytokines production by ILC2, and this effect was blocked by anti-TSLP. Our results also showed that the miR-375 inhibitors attenuate allergic symptoms and production of type II cytokines in AR mice.

Conclusions

Our findings suggest that miR-375-mediated regulation of ILC2 cells through TSLP, providing new potential treatment target for AR.

Emerging role of non-coding RNAs in allergic disorders

RNA transcripts that not undergo translation into polypeptides recently came into focus of research. Long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs) comprise the most important groups of these transcripts. LncRNAs have a length over 200 nucleotides and like mRNAs, have regulated transcription in a tissue specific manner. Biogenesis and function of lncRNAs is related to cell differentiation, response to stimuli and regulation of immune responses. LncRNAs can interact with both miRNAs and mRNAs. MiRNAs are characterized by a length of 22-24 nucleotides. MiRNAs regulate expression of genes at the post-transcriptional level. LncRNAs together with miRNAs are considered as regulators of the immune system. Alterations in their biogenesis is an important mechanism in the development immune related disorders. CircRNAs are products of aberrant maturation of protein-coding transcripts in a process of back-splicing, in which a single strand RNA molecule attains a closed circle shape. Despite a low expression, some circRNA were found to titrate miRNAs and interfere with maturation of legitimate protein-coding transcripts. We summarize the current knowledge on the role of non-coding transcripts in allergic disorders: asthma, atopic dermatitis, allergic rhinitis and urticaria. The reviewed data suggest lncRNA and miRNAs as therapeutic targets and biomarkers of allergic disorders.

Predictors for Short-Term Efficacy of Allergen-Specific Sublingual Immunotherapy in Children with Allergic Rhinitis

Background

A good compliance in allergen-specific sublingual immunotherapy (SLIT) often comes from good short-term efficacy. We aimed to evaluate the pretreatment parameters which can predict the short-term clinical efficacy in children that underwent SLIT.

Methods

517 children with allergic rhinitis (AR) that underwent SLIT were recruited in this study. Baseline clinical characteristics and laboratory parameters were collected, and the clinical efficacy was evaluated using symptom and medication scores. A multivariate logistic regression model and receiver operating characteristic (ROC) curves were established.

Results

A total of 303 (65%) in 466 children that underwent SLIT achieved short-term clinical efficacy. The time of using the air conditioner was negatively correlated with clinical efficacy, whereas the serum-specific IgE (s-IgE) levels, the serum IL-10 and IL-35 levels, and the s-IgE/total-IgE ratio were positively correlated with clinical efficacy.

Conclusion

The time of using the air conditioner, serum-specific IgE (s-IgE) levels, serum IL-10 and IL-35 levels, and s-IgE/total-IgE ratio may be helpful for child selection before SLIT.

Principles of Allergen Immunotherapy and Its Clinical Application in China: Contrasts and Comparisons with the USA

Allergen immunotherapy (AIT) for allergic rhinitis (AR), asthma, and other allergic diseases has developed quickly. House dust mite (HDM), Artemisia (wormwood), Humulus japonicus (Japanese hop), Alternaria alternata, and Cladosporium herbarum are the five most common inhalant allergens in China. AIT has been performed in China for over 60 years. With the support of the Chinese Medical Association (CMA) and the Chinese Medical Doctors Association (CMDA), the Chinese College of Allergy and Asthma (CCAA) was established in 2016 as a specialized branch of CDMA and is the main certification authority for AIT. Chinese allergists and scientists have made tremendous progress in the development of AIT. There have been many publications by Chinese allergists and scientists worldwide encompassing original research studies, systematic reviews, case studies, and clinical trials. Currently, conventional subcutaneous immunotherapy (SCIT) is the preferred AIT in China, but sublingual immunotherapy (SLIT) is beginning to gain recognition. An increasing number of clinical trials have been conducted to investigate the clinical efficacy and side effects of SLIT and SCIT. In China, HDM is the only commercial standardized allergen extracts in clinical use, whereas the others are crude allergen extracts. Besides standardized allergen extracts, other forms of hypoallergenic extracts are still being investigated and developed in China. Immunotherapy in China is similar to that in the USA in which allergen extracts can be mixed for SCIT. However, allergen extracts cannot be mixed for SCIT in Europe.

House dust mite subcutaneous immunotherapy in Chinese patients with allergic asthma and rhinitis

The efficacy of allergen immunotherapy (AIT) has been reported with different allergens including house dust mites (HDM). HDM are the most prevalent allergens in patients with asthma and/or rhinitis in China. In addition to improving symptoms, reducing medication need, and improving quality of life, AIT can change the course of allergic disease and induce allergen-specific immune tolerance. To date, the use of AIT is becoming more acceptable in China, and there are many studies about the current clinical practice immunotherapy. In this paper we discuss the main aspects of AIT undertaken in China; including symptom and medication scores, pulmonary function and airway hyperresponsiveness, specific allergen sensitivity, safety evaluation, and mechanisms underlying AIT. This review will provide some important information on AIT treatment strategies to doctors, healthcare professionals and organizations involved in the AIT in China. According to the studies in China, successful AIT may induce antibody responses and cellular reactions in relation to the significant improvement in clinical symptoms, reducing the need for medications and maintenance of stable pulmonary functions.

MicroRNAs: Potential Biomarkers and Targets of Therapy in Allergic Diseases?

MicroRNAs (miRNAs) are small non-coding RNA molecules that are 18-22 nucleotides long and highly conserved throughout evolution. Currently, they are considered one of the fundamental regulatory mechanisms of genes expression. It has been demonstrated that miRNAs are involved in many biologic processes, such as signal transduction, cell proliferation and differentiation, apoptosis and stress responses. More recently, the role of miRNA has also been revealed in numerous immunological and inflammatory disorders, including allergic inflammation. Specific miRNA profiles were demonstrated in asthma, allergic rhinitis and atopic dermatitis. A core set of miRNAs involved in atopic diseases include upregulated miR-21, miR-223, miR-146a, miR-142-5p, miR-142-3p, miR-146b, miR-155 and downregulated let-7 family, miR-193b and miR-375. Most of the involved miRNAs increase secretion of Th2 cytokines (miR-1248, miR-146b), decrease secretion of Th1 cytokines (miR-513-5p, miR-625-5p) or promote differentiation of T cells towards Th2 (miR-21, miR-19a). In asthma miR-140-3p, miR-708 and miR-142-3p play a role in hyperplasia and hypertrophy of bronchial smooth muscle cells. Some single miRNAs or, more probably, their sets hold the promise for their use as biomarkers of atopic diseases. They are also promising target of future therapies.

MicroRNA-466a-3p attenuates allergic nasal inflammation in mice by targeting GATA3

Allergic rhinitis is thought to be an allergic disease associated with immunoglobulin (Ig)E-mediated immune response, characterized by increased T helper type 2 (Th2) cytokine production, elevated eosinophil levels in the nasal mucosa and induced nasal secretions. MicroRNA (miRNA) microarray data revealed that the expression level of miR-466a-3p was significantly decreased. Notably, GATA binding protein (GATA-3) was identified as one of its target genes through miRNA target prediction web tools. The expression levels of miR-466a-3p were altered by mimics and lentivirus both in vivo and in vitro, similar to those of GATA-3. Furthermore, the symptoms and histology of allergic rhinitis as well as the levels of serum IgE and interleukin (IL)-4 were examined in different groups of mice. Interestingly, the results for lentiviral miR-466a-3p-treated allergic rhinitis mice were relatively similar to normal mice, compared to allergic rhinitis mice without treatment. Also, miR-466a-3p negatively regulated GATA-3 expression in allergic rhinitis mice, indicating the participant of Th2-cell responses in allergic rhinitis. Taken together, our findings highlight a new perspective on the role of miR-466a-3p in allergic rhinitis. In addition, this study provides a theoretical framework and experimental reference for future research targeting microRNAs as therapeutic targets and diagnostic biomarkers of allergic rhinitis.

Plasma microRNA-21, microRNA-146a and IL-13 expression in asthmatic children

Childhood asthma represents a worldwide problem, involving genetic, immune defense and environmental components. MicroRNAs (miRs) are non-coding, single-stranded RNAs involved in immune regulation. The aim was to evaluate clinical potential of plasma miR-21 and miR-146a involved in T helper differentiation in childhood asthma and non-asthmatic controls. Group 1 consisted of 27 asthmatic children receiving inhaled corticosteroids (ICSs), which was compared to group 2 with 21 healthy control children. All patients were assessed by pulmonary function tests. miR-21 and miR-146a expression levels were determined by real-time quantitative PCR, and IL-13 was measured using ELISA. Group 1 showed significant up-regulation of plasma miR-21 and miR-146a levels with mean values 42.6-fold and 4.7-fold higher than average expression, respectively, in group 2. miR-21 levels positively correlated with IL-13 levels and eosinophil percentage, while miR-146a only correlated to eosinophil percentage. There was a linear association between each of miR-21 and miR-146a expression and FEV1 (forced expiratory volume in the first second), miR-21 and miR-146a are up-regulated in asthmatic children. miR-21 served as a better asthma biomarker. Association between both markers and FEV1 points to their role in determining asthma outcome following ICS treatment. miR-21 and miR-146a play a role in eosinophilic endotypic classification of asthma.

Epigenetic changes: An emerging potential pharmacological target in allergic rhinitis

The importance of epigenetics has increased due to identification of its role in the pathophysiology of a number of diseases including allergic rhinitis. Amongst the different epigenetic changes in allergic retinitis, deacetylation of histone proteins by histone deacetylase (HDACs), hypermethylation of DNA by DNA methyltransferases (DNMT) and alteration in post-transcriptional process by the changes in the levels of miRNA are widely studied. Studies conducted related to allergic rhinitis have shown the elevation in the levels of HDAC1, 3 and 11 in the nasal epithelia and HDAC inhibitors have shown effectiveness in decreasing the symptoms of rhinitis. Their beneficial effects are attributed to restoration of the expression of TWIK-related potassium channel-1, correction of cytokine profile along with normalization of Th1/Th2 imbalance. Another epigenetic change due to increase in DNMT activity may induce DNA hypermethylation in CpG sites in the airway epithelial cells and CD4⁺ T-cells. The reduction in DNA methylation decreases allergic symptoms and normalizes the over-reactive immune system. Mechanistically, allergens may promote the hypermethylation in the promoter region of IFN-γ gene in CD4⁺ T cells via activation of ERK pathway to decrease the expression of IFN-γ. In allergic rhinitis patients, there is also a downregulation of certain miRNAs including miR-135a, miR-146a, miR-181a, miR-155 and upregulation of miRNA19a. This review discusses the studies describing the epigenetic changes taking place in the host cells in response to allergen along with possible mechanisms.

Randomized controlled trial on the influence of dietary intervention on epigenetic mechanisms in children with cow's milk allergy: the EPICMA study

Epigenetic mechanisms could drive the disease course of cow’s milk allergy (CMA) and formula choice could modulate these pathways. We compared the effect of two different dietary approaches on epigenetic mechanisms in CMA children. Randomized controlled trial on IgE-mediated CMA children receiving a 12-month treatment with extensively hydrolyzed casein formula containing the probiotic L.rhamnosus GG (EHCF + LGG) or with soy formula (SF). At the baseline, after 6 and 12 months of treatment FoxP3 methylation rate and its expression in CD4⁺ T cells were assessed. At same study points IL-4, IL-5, IL-10, and IFN-γ methylation rate, expression and serum concentration, miRNAs expression were also investigated. 20 children (10/group) were evaluated. Baseline demographic, clinical and epigenetic features were similar in the two study groups. At 6 and 12 months, EHCF + LGG group showed a significant increase in FoxP3 demethylation rate compared to SF group. At the same study points, EHCF + LGG group presented a higher increase in IL-4 and IL-5 and a higher reduction in IL-10 and IFN-γ DNA methylation rate compared to SF group. A different modulation of miR-155, -146a, -128 and -193a expression was observed in EHCF + LGG vs. SF. Dietary intervention could exert a different epigenetic modulation on the immune system in CMA children.

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

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

microRNA diagnostic panel for Alzheimer's disease and epigenetic trade-off between neurodegeneration and cancer

microRNAs (miRNAs) have been extensively studied as potential biomarkers for Alzheimer's disease (AD). Their profiles have been analyzed in blood, cerebrospinal fluid (CSF) and brain tissue. However, due to the high variability between the reported data, stemming from the lack of methodological standardization and the heterogeneity of AD, the most promising miRNA biomarker candidates have not been selected. Our literature review shows that out of 137 miRNAs found to be altered in AD blood, 36 have been replicated in at least one independent study, and out of 166 miRNAs reported as differential in AD CSF, 13 have been repeatedly found. Only 3 miRNAs have been consistently reported as altered in three analyzed specimens: blood, CSF and the brain (hsa-miR-146a, hsa-miR-125b, hsa-miR-135a). Nonetheless, all 36 repeatedly differential miRNAs in AD blood are promising as components of the diagnostic panel. Given their predicted functions, such miRNA panel may report multiple pathways contributing to AD pathology, enabling the design of personalized therapies. In addition, the analysis revealed that the miRNAs dysregulated in AD overlap highly with miRNAs implicated in cancer. However, the directions of the miRNA changes are usually opposite in cancer and AD, indicative of an epigenetic trade-off between the two diseases.

The efficacy of sublingual immunotherapy for allergic diseases in Asia

Sublingual immunotherapy (SLIT) has been proven to be safe and effective from an abundance of Western literature, but data from Asia is less complete. This review aims to examine the basic science, safety and efficacy of SLIT in Asian patients, and to determine future research needs in Asia. We performed a literature search on PUBMED, Scopus, and Cochrane Library database for articles on SLIT originating from Asian countries through Nov 2017. There were 18 randomized, double-blind, placebo-controlled trials, of which 9 involved solely paediatric subjects. Overall, sublingual immunotherapy is safe and is efficacious in Asian populations in allergic rhinitis (AR) and asthma. House dust-mite SLIT is effective in both mono- and polysensitized AR patients. Efficacy of SLIT is comparable to subcutaneous immunotherapy. Data on long term efficacy is lacking. A disproportionate majority of research originates from China and Japan, reflecting an asymmetry of access to SLIT within Asia. Significant disparities exist in the development of the allergy speciality, prescription patterns of SLIT, and pharmacological potencies of different SLIT products within and between Asian nations. We conclude that current available evidence suggests SLIT is efficacious in Asians but data quality of evidence is hampered by non-placebo controlled studies with methodological limitations. More data is needed in South and Southeast Asian populations. Future efforts may be directed towards improving access to SLIT in developing countries, standardization of SLIT dosage, and evaluating long term clinical outcomes.

Chinese Society of Allergy Guidelines for Diagnosis and Treatment of Allergic Rhinitis

Allergic rhinitis (AR) is a global health problem that causes major illnesses and disabilities worldwide. Epidemiologic studies have demonstrated that the prevalence of AR has increased progressively over the last few decades in more developed countries and currently affects up to 40% of the population worldwide. Likewise, a rising trend of AR has also been observed over the last 2-3 decades in developing countries including China, with the prevalence of AR varying widely in these countries. A survey of self-reported AR over a 6-year period in the general Chinese adult population reported that the standardized prevalence of adult AR increased from 11.1% in 2005 to 17.6% in 2011. An increasing number of Journal Articles and imporclinical trials on the epidemiology, pathophysiologic mechanisms, diagnosis, management and comorbidities of AR in Chinese subjects have been published in international peer-reviewed journals over the past 2 decades, and substantially added to our understanding of this disease as a global problem. Although guidelines for the diagnosis and treatment of AR in Chinese subjects have also been published, they have not been translated into English and therefore not generally accessible for reference to non-Chinese speaking international medical communities. Moreover, methods for the diagnosis and treatment of AR in China have not been standardized entirely and some patients are still treated according to regional preferences. Thus, the present guidelines have been developed by the Chinese Society of Allergy to be accessible to both national and international medical communities involved in the management of AR patients. These guidelines have been prepared in line with existing international guidelines to provide evidence-based recommendations for the diagnosis and management of AR in China.

Treatment of Allergic Rhinitis as a Strategy for Preventing Asthma

PURPOSE OF REVIEW

To evaluate the impact of allergic rhinitis (AR) on the development of asthma and to update readers on recent literature suggesting that early treatment of allergic subjects with immunotherapy may prevent asthma onset.

RECENT FINDINGS

AR is frequently associated with asthma, leading to the concept that these two conditions are different aspects of the same disease. There is increasing evidence that AR precedes the onset of asthmatic symptoms and current treatment strategies are beneficial in symptom control with no impact prevention. There is limited knowledge about the risk factors responsible for the progression of AR to asthma, though recent data supports the notion that it is possible to prevent asthma onset by allergen immunotherapy. Despite significant advances in specific immunotherapy (SIT) therapy strengthening its efficacy in AR and possible prevention of progression to asthma, the adoption of this therapeutic strategy is still restricted in comparison to therapies directed towards treatment of AR symptoms. Unlike corticosteroids and other symptomatic therapies, the benefit of SIT treatment in allergic individuals has been shown to prevent the development of allergic conditions. Hence, large well-conducted randomized clinical trials with long-term efficacy of SIT are required to confirm or refute the concept that SIT may abrogate the progression of AR to asthma in patients.

Correlation of microRNA profiles with disease risk and severity of allergic rhinitis

To explore the correlation of microRNA (miRNA) profiles with disease risk and severity in patients with allergic rhinitis (AR). miRNA expression profiles in nasal mucosa samples from 8 AR patients and 8 matched non-atopic controls were detected by microarray. Twelve differentially expressed miRNAs (DEMs) in microarray analysis were further validated in nasal mucosa samples from 48 AR patients and 50 controls by qPCR assay. Individual nasal symptom score (INSS) and total nasal symptom score (TNSS) were used to evaluated the disease severity of AR. AR patients could be distinguished from controls according to the principal component analysis (PCA) plot analysis in the microarray, and 27 down-regulated and 51 up-regulated DEMs were identified by volcano plot. qPCR validation disclosed that miR-126-5p, miR-19a-5p and miR-26a-5p expression was up-regulated in AR patients compared with controls. Multivariate logistic regression displayed that miR-126-5p, miR-19a-5p and miR-26a-5p are independent predictive factors for AR risk, and receiver operating characteristic (ROC) analysis exhibited that the combination of miR-126-5p, miR-19a-5p and miR-26a-5p predicts the risk of AR with a high area under curve (AUC) of 0.866 (95% CI: 0.797-0.936). In addition, expression of miR-126-5p, miR-19a-5p and miR-181c-3p were positively correlated with TNSS. Therefore, miRNA profiles distinguish AR patients from controls and the combination of miR-126-5p, miR-19a-5p and miR-26a-5p could serve as novel biomarker for AR risk.

Chinese Guideline on allergen immunotherapy for allergic rhinitis

The present document is based on a consensus reached by a panel of experts from Chinese Society of Allergy (CSA) and Chinese Allergic Rhinitis Collaborative Research Group (C2AR2G). Allergen immunotherapy (AIT), has increasingly been used as a treatment for allergic rhinitis (AR) globally, as it has been shown to provide a long-term effect in improving nasal and ocular symptoms, reducing medication need, and improving quality of life. AIT is currently the only curative intervention that can potentially modify the immune system in individuals suffering from AR and prevent the development of new sensitization and the progression of disease from AR to asthma. Although the use of AIT is becoming more acceptable in China, to date no AR immunotherapy guideline from China is available for use by the international community. This document has thus been produced and covers the main aspects of AIT undertaken in China; including selection of patients for AIT, the allergen extracts available on the Chinese market, schedules and doses of allergen employed in different routes of AIT, assessment of effect and safety, patients' administration and follow-up, and management of adverse reactions. The Chinese guideline for AR immunotherapy will thus serve as a reference point by doctors, healthcare professionals and organizations involved in the AIT of AR in China. Moreover, this guideline will serve as a source of information for the international community on AIT treatment strategies employed in China.

Immune biomarkers in the spectrum of childhood noncommunicable diseases

A biomarker is an accurately and reproducibly quantifiable biological characteristic that provides an objective measure of health status or disease. Benefits of biomarkers include identification of therapeutic targets, monitoring of clinical interventions, and development of personalized (or precision) medicine. Challenges to the use of biomarkers include optimizing sample collection, processing and storage, validation, and often the need for sophisticated laboratory and bioinformatics approaches. Biomarkers offer better understanding of disease processes and should benefit the early detection, treatment, and management of multiple noncommunicable diseases (NCDs). This review will consider the utility of biomarkers in patients with allergic and other immune-mediated diseases in childhood. Typically, biomarkers are used currently to provide mechanistic insight or an objective measure of disease severity, with their future role in risk stratification/disease prediction speculative at best. There are many lessons to be learned from the biomarker strategies used for cancer in which biomarkers are in routine clinical use and industry-wide standardized approaches have been developed. Biomarker discovery and validation in children with disease lag behind those in adults; given the early onset and therefore potential lifelong effect of many NCDs, there should be more studies incorporating cohorts of children. Many pediatric biomarkers are at the discovery stage, with a long path to evaluation and clinical implementation. The ultimate challenge will be optimization of prevention strategies that can be implemented in children identified as being at risk of an NCD through the use of biomarkers.

Altered miR-155 Expression in Allergic Asthmatic Airways

We and others have previously identified microRNAs (miRNAs) with pathological roles in animal models of asthma, where miR-146a and miR-155 have been described to play important roles in inflammatory responses. To date, few studies have investigated miRNA expression in human asthmatics. In the current study, significantly lower levels of miR-155 were detected in cell-free sputum from allergic asthmatics compared to healthy controls. Induced sputum isolated from allergic asthmatics in and out of pollen season revealed that miR-155 expression, but not miR-146a, is reduced in lymphocytes in season compared to post-season. In contrast, miR-155 was found to increase, whereas miR-146a decreased in PBMCs and cell-free PBMC culture media upon T cell receptor stimulation via αCD3/CD28 in both allergic asthmatics and healthy controls. Our findings suggest that miR-155 is differentially expressed ex vivo in airways of allergic asthmatics compared to healthy controls, which may have implications in the local immune response in allergic asthma.

MicroRNA-146a induction during influenza H3N2 virus infection targets and regulates TRAF6 levels in human nasal epithelial cells (hNECs)

We have previously shown that human nasal epithelial cells (hNECs) are highly permissive cells for respiratory viruses including influenza A virus (IAV) and respiratory syncytial virus. Recent studies have indicated that microRNAs (miRNAs) are involved in virus-host relationship, and this led us to investigate its essential roles in the in vitro hNECs model derived from multiple donors. By comparing the differential expression of miRNAs upon IAV infection among animal and cell line studies, candidates were selected with focus on the initial immune response. After infection of influenza H3N2 virus, hNECs showed constant increase virus titer at 24-72h post-infection (hpi); accompanied with a significantly elevated level of miR-146a-5p at 72 hpi. The exponential elevation of progeny virus titer correlated with a key influenza sensing Toll-like receptor (TLR)7 pathway. TLR7 downstream gene transcripts, myeloid differentiation primary response gene 88 (MyD88), interferon regulator factor 7 (IRF7), and interferon-β (IFN-β) were significantly upregulated at 48 and 72 hpi, while interleukin-1 receptor-associated kinase 1 (IRAK1) and TNF receptor associated factor-6 (TRAF6) were unchanged. Interestingly, when miR-146a was overexpressed with miRNA mimics prior to H3N2 infection, further decreased transcripts of TRAF6, but not IRAK1, were detected. By using the in vitro hNEC model, we demonstrated that H3N2-induced miR-146a specifically targets and regulates TRAF6 expression; but not IRAK expression in the nasal epithelium. We also found that unlike the cell model studies that lead to our studies, when ran across a heterogeneous model of different individual, miRNA signals were highly varied and the expression of most miRNAs, including miR-146a-5p, was more subdued compared to homogenous cell line model, highlighting a need for a more thorough analysis of miRNA signals and targets in a model more mimicking a clinical influenza infection.

MicroRNAs: New regulators of IL-22

Interleukin-22 (IL-22) is a cytokine that belongs to the IL-10 family of interleukins. It can be produced by T helper 22 (Th22) cells, T helper 1 (Th1) cells, T helper 17 (Th17) cells, natural killer 22 (NK22) cells, natural killer T (NKT) cells, innate lymphoid cells (ILCs), and γδ T cells. IL-22 acts via binding to a heterodimeric transmembrane receptor complex that consists of IL-22R1 and IL-10R2 and mainly contributes to the tissue repair and host defense. Transcription factors such as retinoid orphan receptor γt (RORγt) and signal transducer and activator of transcription 3 (STAT3), have been reported to play important roles in regulation of IL-22 expression. Recently, it has been demonstrated in several studies that microRNAs (miRNAs) potently regulate expression of interleukins, including production of IL-22. Here, we review current knowledge about regulators of IL-22 expression with a particular emphasis on the role of miRNAs.

MicroRNA in United Airway Diseases

The concept of united airway diseases (UAD) has received increasing attention in recent years. Sustained and increased inflammation is a common feature of UAD, which is inevitably accompanied with marked gene modification and tight gene regulation. However, gene regulation in the common inflammatory processes in UAD remains unclear. MicroRNA (miRNA), a novel regulator of gene expression, has been considered to be involved in many inflammatory diseases. Although there are an increasing number of studies of miRNAs in inflammatory upper and lower airway diseases, few miRNAs have been identified that directly link the upper and lower airways. In this article, therefore, we reviewed the relevant studies available in order to improve the understanding of the roles of miRNAs in the interaction and pathogenesis of UAD.