Differential Expression of Serum MicroRNAs Supports CD4⁺ T Cell Differentiation into Th2/Th17 Cells in Severe Equine Asthma

Profiling host- and parasite-derived miRNAs associated with Strongylus vulgaris infection in horses

The equine bloodworm, Strongylus vulgaris, is a common and highly pathogenic parasite in horses due to its migratory life cycle involving the intestinal arteries. Current diagnostic techniques cannot detect the prepatent migrating stages of S. vulgaris, highlighting the need for new biomarkers. Parasites release microRNAs (miRNAs) into their environment, which could potentially be detectable in host blood samples. Additionally, host miRNA expression patterns may change in response to infection. This study aimed to identify miRNAs associated with S. vulgaris infection by profiling the horse's miRNA response in the larval predilection site, the Cranial Mesenteric Artery (CMA) and examining the circulating parasite and horse-derived miRNAs in plasma of S. vulgaris-infected horses. Plasma samples were collected from 27 horses naturally infected with S. vulgaris and 28 uninfected horses. Arterial tissue samples from the CMA and Aorta were collected from a subset (n = 12) of the infected horses. Small RNA sequencing (small RNAseq) of a subset of the plasma samples (n = 12) identified miRNAs of interest, followed by quantitative real-time PCR (qPCR) evaluation of selected miRNAs in plasma from a larger cohort of horses. Small RNAseq detected 138 parasite-derived and 533 horse-derived miRNAs in the plasma samples. No difference in parasite-derived miRNA abundance was found between the infected and uninfected horses, but 140 horse-derived miRNAs were significantly differentially abundant between the two groups. When evaluated by qPCR, none of the selected parasite-derived miRNAs were detectable in plasma, but seven horse-derived miRNAs were confirmed differentially abundant in plasma between the two groups. Seven horse-derived miRNAs were differentially expressed in CMA tissue affected by migrating S. vulgaris compared with unaffected aortic tissue, with Eca-Mir-223-3p (Log2FC: 4.74) and Eca-Mir-140-3p (Log2FC: -3.64) being most differentially expressed. A receiver operating characteristic curve analysis suggested that Eca-Mir-486-5p and Eca-Mir-140-3p had the best diagnostic performance for distinguishing between infected and uninfected horses, with areas under the curve (AUC) of 0.78 and 0.77, respectively. Notably, Eca-Mir-140-3p was associated with age, and correcting for interaction with age increased the AUC to 0.96. In conclusion, several horse-derived miRNAs were associated with S. vulgaris infection and could differentiate between infected and uninfected horses based on their plasma abundance. However, the levels of these miRNAs were influenced by other factors (i.e age, breed), complicating their use as biomarkers. Parasite-derived miRNA abundance did not differ between S. vulgaris infected horses and those infected with other parasites using small RNAseq and were below detection limits of qPCR.

Evaluation of circulating miRNAs in mares approaching parturition

Circulating microRNAs (miRNAs) are stable in body fluids and can serve as biomarkers for various diseases and physiological states. Although pregnancy-related miRNAs have been identified in various mammals, studies on parturition-related circulating miRNAs in mares are limited. Therefore, this study aimed to identify parturition-related miRNAs and examine their potential applications in the prediction of parturition date. miRNAs were extracted from the plasma of Thoroughbred mares 30 days (295-326 days pregnant) and 5 (323-352 days pregnant) - 0 (328-357 days pregnant) days before parturition, followed by small RNA sequencing (small RNA-seq) and reverse transcription quantitative PCR (RT-qPCR). Additionally, we measured plasma progestin concentrations in mares using an enzyme-linked immunosorbent assay. Small RNA-seq data indicated that 18 miRNAs were affected by parturition proximity. Among the 18 miRNAs, two novel miRNAs and three known miRNAs (miR-361-3p, miR-483, and miR-99a) showed significant changes at 5-0 days before parturition compared with that at 30 days to parturition. Plasma progestin concentrations were higher at 5-3 days to parturition than at 30 days to parturition, and then decreased on the day of parturition. Conclusively, this study provides basic knowledge of parturition-related circulating miRNAs in mares, and identifies miRNAs that could potentially be used as biomarkers to predict parturition in mares.

Targeting microRNAs as a promising anti-cancer therapeutic strategy against traffic-related air pollution-mediated lung cancer

Air pollutants are increasingly emitted into the atmosphere because of the high dependency of humans on fossil-derived fuels. Wind speed and direction assisted high dispersibility and uncontrolled nature of air pollution across geo-/demographical borders, making it one of the major global concerns. Besides climate change, air pollution has been found to be associated with various diseases, such as cancer. Lung cancer, which is the world's most common type of cancer, has been found to be associated with traffic-related air pollution. Research and political efforts have been taken to explore green/renewable energy sources. However, these efforts at the current intensity cannot cope with the increasing need for fossil fuels. More specifically, political tensions such as the Russian-Ukraine war, economic tension (e.g., China-USA economic tensions), and other issues (e.g., pandemic, higher inflation rate, and poverty) significantly hindered phasing out fossil fuels. In this context, an increasing global population will be exposed to traffic-related air pollution, which justifies the current uptrend in the number of lung cancer patients. To combat this health burden, novel treatments with higher efficiency and specificity must be designed. One of the potential "life changer" options is microRNA (miRNA)-based therapy to target the expression of oncogenic genes. That said, this review discusses the association of traffic-related air pollution with lung cancer, the changes in indigenous miRNAs in the body during lung cancer, and the current status of miRNA therapeutics for lung cancer treatment. We believe that the article will significantly appeal to a broad readership of oncologists, environmentalists, and those who work in the field of (bio)energy. It may also gain the policymakers' attention to establish better health policies and regulations about air pollution, for example, by promoting (bio)fuel exploration, production, and consumption.

Cytokine mRNA expression in the bronchoalveolar lavage cells from horses affected by different equine asthma subtypes

Equine asthma (EA) is a respiratory syndrome associated with the increase of different leukocyte populations in the bronchoalveolar lavage fluid (BALF). Its pathogenetic mechanisms remain unclear. This study aimed to evaluate the associations between the mRNA expression of different cytokines in the BALF, different EA subtypes and lung function. Fifteen horses underwent physical examination, airway endoscopy, BALF cytology and lung function testing (8/15). One horse did not have evidence of EA and was used as healthy reference, while the others were classified as affected by neutrophilic or mixed granulocytic EA. Cells isolated from the residual BALF were used for IL-1β, IL-2, IFN-γ, IL-4, IL-17A genes expression by quantitative RT-PCR., Cytokine expression was compared between groups, and their correlations with BALF leukocyte and lung function were evaluated. IL-1β expression was positively correlated with BALF neutrophils count (p=0.038, r=0.56) and with increased expiratory resistance (p=0.047, r=0.76). IFN-γ was correlated with BALF mast cells (p=0.029, r=0.58). IL-4 was higher in horses with mixed granulocytic EA than neutrophilic (p=0.008), positively correlated with BALF mast cells (p=0.028, r=0.59) and inversely with whole-breath (p=0.046, r=-0.76) and expiratory reactance (p=0.003, r=-0.93). Finally, IL-17A was inversely correlated with expiratory reactance (p=0.009, r=-0.92). These results support that multiple immune responses are involved in EA pathogenesis; innate, Th2, and Th17 responses. Innate immunity appeared associated with neutrophilic inflammation, and Th2 response with increased mast cells. The role of Th1 response in EA remains questionable.

Single-cell profiling of bronchoalveolar cells reveals a Th17 signature in neutrophilic severe equine asthma

Severe equine asthma (SEA) is a complex respiratory condition characterized by chronic airway inflammation. It shares many clinical and pathological features with human neutrophilic asthma, making it a valuable model for studying this condition. However, the immune mechanisms driving SEA have remained elusive. Although SEA has been primarily associated with a Th2 response, there have also been reports of Th1, Th17, or mixed-mediated responses. To uncover the elusive immune mechanisms driving SEA, we performed single-cell mRNA sequencing (scRNA-seq) on cryopreserved bronchoalveolar cells from 11 Warmblood horses, 5 controls and 6 with SEA. We identified six major cell types, including B cells, T cells, monocytes-macrophages, dendritic cells, neutrophils, and mast cells. All cell types exhibited significant heterogeneity, with previously identified and novel cell subtypes. Notably, we observed monocyte-lymphocyte complexes and detected a robust Th17 signature in SEA, with CXCL13 upregulation in intermediate monocytes. Asthmatic horses exhibited expansion of the B-cell population, Th17 polarization of the T-cell populations, and dysregulation of genes associated with T-cell function. Neutrophils demonstrated enhanced migratory capacity and heightened aptitude for neutrophil extracellular trap formation. These findings provide compelling evidence for a predominant Th17 immune response in neutrophilic SEA, driven by dysregulation of monocyte and T-cell genes. The dysregulated genes identified through scRNA-seq have potential as biomarkers and therapeutic targets for SEA and provide insights into human neutrophilic asthma.

Decision Making in Severe Equine Asthma-Diagnosis and Monitoring

Decision making consists of gathering quality data in order to correctly assess a situation and determine the best course of action. This process is a fundamental part of medicine and is what enables practitioners to accurately diagnose diseases and select appropriate treatment protocols. Despite severe equine asthma (SEA) being a highly prevalent lower respiratory disease amongst equids, clinicians still struggle with the optimization of routine diagnostic procedures. The use of several ancillary diagnostic tests has been reported for disease identification and monitoring, but many are only suitable for research purposes or lack practicality for everyday use. The aim of this paper is to assist the equine veterinarian in the process of decision making associated with managing SEA-affected patients. This review will focus on disease diagnosis and monitoring, while also presenting a flow-chart which includes the basic data that the clinician must obtain in order to accurately identify severely asthmatic horses in their everyday routine practice. It is important to note that European and American board-certified specialists on equine internal medicine can provide assistance in the diagnosis and treatment plan of SEA-affected horses.

Changes in miRNA expression in the lungs of pigs supplemented with different levels and forms of vitamin D

BACKGROUND

Vitamin D is an immunomodulator, and its effects have been linked to many diseases, including the pathogenesis of cancer. However, the effect of vitamin D supplementation on the regulation of gene expression of the lungs is not fully understood. This study aims to determine the effect of the increased dose of cholecalciferol and a combination of cholecalciferol + calcidiol, as well as the replacement of cholecalciferol with calcidiol, on the miRNA profile of healthy swine lungs.

METHODS AND RESULTS

The swine were long-term (88 days) supplemented with a standard dose (2000IU/kg) of cholecalciferol and calcidiol, the increased dose (3000 IU/kg) of cholecalciferol, and the cholecalciferol + calcidiol combination: grower: 3000 IU/Kg of vitamin D (67% of cholecalciferol and 33% of calcidiol), finisher 2500 IU/Kg of vitamin D (60% of cholecalciferol and 40% of calcidiol). Swine lung tissue was used for Next Generation Sequencing (NGS) of miRNA. Long-term supplementation with the cholecalciferol + calcidiol combination caused significant changes in the miRNA profile. They embraced altered levels of the expression of miR-150, miR-193, miR-145, miR-574, miR-340, miR-381, miR-148 and miR-96 (q-value < 0.05). In contrast, raising the dose of cholecalciferol only changed the expression of miR-215, and the total replacement of cholecalciferol with calcidiol did not significantly affect the miRNAome profile.

CONCLUSIONS

The functional analysis of differentially expressed miRNAs suggests that the use of the increased dose of the cholecalciferol + calcidiol combination may affect tumorigenesis processes through, inter alia, modulation of gene regulation of the TGF- β pathway and pathways related to metabolism and synthesis of glycan.

Single-cell transcriptomics delineates the immune cell landscape in equine lower airways and reveals upregulation of FKBP5 in horses with asthma

Equine asthma (EA) is a heterogenous, complex disease, with a significant negative impact on horse welfare and performance. EA and human asthma share fundamental similarities, making EA a useful model for studying the disease. One relevant sample type for investigating chronic lung inflammation is bronchoalveolar lavage fluid (BALF), which provides a snapshot of the immune cells present in the alveolar space. To investigate the immune cell landscape of the respiratory tract in horses with mild-to-moderate equine asthma (mEA) and healthy controls, single-cell RNA sequencing was conducted on equine BALF cells. We characterized the major immune cell populations present in equine BALF, as well as subtypes thereof. Interestingly, the most significantly upregulated gene discovered in cases of mEA was FKBP5, a chaperone protein involved in regulating the activity of the glucocorticoid receptor.

Unraveling Therapeutic Opportunities and the Diagnostic Potential of microRNAs for Human Lung Cancer

Lung cancer is a major public health problem and a leading cause of cancer-related deaths worldwide. Despite advances in treatment options, the five-year survival rate for lung cancer patients remains low, emphasizing the urgent need for innovative diagnostic and therapeutic strategies. MicroRNAs (miRNAs) have emerged as potential biomarkers and therapeutic targets for lung cancer due to their crucial roles in regulating cell proliferation, differentiation, and apoptosis. For example, miR-34a and miR-150, once delivered to lung cancer via liposomes or nanoparticles, can inhibit tumor growth by downregulating critical cancer promoting genes. Conversely, miR-21 and miR-155, frequently overexpressed in lung cancer, are associated with increased cell proliferation, invasion, and chemotherapy resistance. In this review, we summarize the current knowledge of the roles of miRNAs in lung carcinogenesis, especially those induced by exposure to environmental pollutants, namely, arsenic and benzopyrene, which account for up to 1/10 of lung cancer cases. We then discuss the recent advances in miRNA-based cancer therapeutics and diagnostics. Such information will provide new insights into lung cancer pathogenesis and innovative diagnostic and therapeutic modalities based on miRNAs.

Overview of the role and action mechanism of microRNA-128 in viral infections

Recently in vivo and in vitro studies have provided evidence establishing the significance of microRNAs (miRNAs) in both physiological and pathological conditions. In this regard, the role of miRNA-128 (miR-128) in health and diseases has been found, and its critical regulatory role in the context of some viral diseases has been recently identified. For instance, it has been found that miR-128 can serve as an antiviral mediator and significantly limit the replication and dissemination of human immunodeficiency virus type 1 (HIV-1). Besides, it has been noted that poliovirus receptor-related 4 (PVRL4) is post-transcriptionally regulated by miR-128, representing possible miRNA targets that can modulate measles virus infection. Of note, the downregulation of seminal exosomes eca-miR-128 is associated with the long-term persistence of Equine arteritis virus (EAV) in the reproductive tract, and this particular miRNA is a putative regulator of chemokine ligand 16 (C-X-C motif) as determined by target prediction analysis. In this review, the latest information on the role and action mechanism of miR-128 in viral infections will be summarized and discussed in detail.

Exosome RNA Sequencing as a Tool in the Search for Cancer Biomarkers

Numerous noninvasive methods are currently being used to determine biomarkers for diseases such as cancer. However, these methods are not always precise and reliable. Thus, there is an unmet need for better diagnostic and prognostic biomarkers that will be used to diagnose cancer in early, more treatable stages of the disease. Exosomes are extracellular vesicles of endocytic origin released by the majority of cells. Exosomes contain and transport nucleic acids, proteins, growth factors, and cytokines from their parent cells to surrounding or even distant cells via circulation in biofluids. Exosomes have attracted the interest of researchers, as recent data indicate that exosome content may be indicative of disease stages and may contribute to disease progression via exosome-mediated extracellular communication. Therefore, the contents of these vesicles are being investigated as possible biomarkers for disease diagnosis and prognosis. The functions of exosomes and their contents in disease development are becoming clearer as isolation and analytical methods, such as RNA sequencing, advance. In this review, we discuss current advances and challenges in exosomal content analyses with emphasis on information that can be generated using RNA sequencing. We also discuss how the RNA sequencing of exosomes may be used to discover novel biomarkers for the detection of different stages for various cancers using specific microRNAs that were found to be differentially expressed between healthy controls and cancer-diagnosed subjects.

Neutrophil Extracellular Traps Are Found in Bronchoalveolar Lavage Fluids of Horses With Severe Asthma and Correlate With Asthma Severity

Asthma encompasses a spectrum of heterogenous immune-mediated respiratory disorders sharing a similar clinical pattern characterized by cough, wheeze and exercise intolerance. In horses, equine asthma can be subdivided into severe or moderate asthma according to clinical symptoms and the extent of airway neutrophilic inflammation. While severe asthmatic horses are characterized by an elevated neutrophilic inflammation of the lower airways, cough, dyspnea at rest and high mucus secretion, horses with moderate asthma show a milder neutrophilic inflammation, exhibit intolerance to exercise but no labored breathing at rest. Yet, the physiopathology of different phenotypes of equine asthma remains poorly understood and there is a need to elucidate the underlying mechanisms tailoring those phenotypes in order to improve clinical management and elaborate novel therapeutic strategies. In this study, we sought to quantify the presence of neutrophil extracellular traps (NETs) in bronchoalveolar lavage fluids (BALF) of moderate or severe asthmatic horses and healthy controls, and assessed whether NETs correlated with disease severity. To this end, we evaluated the amounts of NETs by measuring cell-free DNA and MPO-DNA complexes in BALF supernatants or by quantifying NETs release by BALF cells by confocal microscopy. We were able to unequivocally identify elevated NETs levels in BALF of severe asthmatic horses as compared to healthy controls or moderate asthmatic horses. Moreover, we provided evidence that BALF NETs release was a specific feature seen in severe equine asthma, as opposed to moderate asthma, and correlated with disease severity. Finally, we showed that NETs could act as a predictive factor for severe equine asthma. Our study thus uniquely identifies NETs in BALF of severe asthmatic horses using three distinct methods and supports the idea that moderate and severe equine asthma do not rely on strictly similar pathophysiological mechanisms. Our data also suggest that NETs represent a relevant biomarker, a putative driver and a potential therapeutic target in severe asthma disease.

Circular RNA has Circ 001372-Reduced Inflammation in Ovalbumin-Induced Asthma Through Sirt1/NFAT5 Signaling Pathway by miRNA-128-3p

In this study, we sought to investigate the prospective role of circ 001372 in modifying inflammation in ovalbumin-induced asthma. In the vivo model of asthma, the serum of circ 001372 was reduced. Down-regulation of circ 001372 increased inflammation reaction (TNF-α, IL-1β, IL-6, and IL-18) and induced COX-2 and iNOS protein expression in vitro model through activation of NFAT5 and suppression of Sirt1. Up-regulation of circ 001372 decreased inflammation reaction (TNF-α, IL-1β, IL-6, and IL-18) in vitro model through inactivation of NFAT5 and induction of Sirt1 by miRNA-128-3p. The miRNA-128-3p lowered the effects of circ 001372 on inflammation in vitro model. The Sirt1 inhibitor reduced the effects of circ 001372 on inflammation in vitro model. Our results revealed the serum of circ 001372 against inflammation in ovalbumin-induced asthma through Sirt1/NFAT5 by miRNA-128-3p.

The Immune Mechanisms of Severe Equine Asthma-Current Understanding and What Is Missing

Severe equine asthma is a chronic respiratory disease of adult horses, occurring when genetically susceptible individuals are exposed to environmental aeroallergens. This results in airway inflammation, mucus accumulation and bronchial constriction. Although several studies aimed at evaluating the genetic and immune pathways associated with the disease, the results reported are inconsistent. Furthermore, the complexity and heterogeneity of this disease bears great similarity to what is described for human asthma. Currently available studies identified two chromosome regions (ECA13 and ECA15) and several genes associated with the disease. The inflammatory response appears to be mediated by T helper cells (Th1, Th2, Th17) and neutrophilic inflammation significantly contributes to the persistence of airway inflammatory status. This review evaluates the reported findings pertaining to the genetical and immunological background of severe equine asthma and reflects on their implications in the pathophysiology of the disease whilst discussing further areas of research interest aiming at advancing treatment and prognosis of affected individuals.

lncRNA-NEAT1 Sponges miR-128 to Promote Inflammatory Reaction and Phenotypic Transformation of Airway Smooth Muscle Cells

OBJECTIVE

Pediatric asthma is still a health threat to the children. Long noncoding RNA-NEAT1 (lncRNA-NEAT1) was reported to be positively correlated with the severity of asthma. We aimed to study the effects and mechanism of lncRNA-NEAT1on inflammatory reaction and phenotypic transformation of airway smooth muscle cells (ASMCs) in the bronchial asthma.

METHOD

The degree of lncRNA-NEAT1 and miR-128 mRNA in children with bronchial asthma and healthy individuals was tested by qRT-PCR. After the inflammatory reaction and phenotypic transformation of PDGF-BB-induced ASMCs, the expression of lncRNA-NEAT1 or miR-128 in the AMSC was disturbed in the AMSC. Subsequently, the expression of lncRNA-NEAT1 and miR-128 was detected by the way of qRT-PCR, and western blot was applied to measure the expression of MMP-2, MMP-9, α-SMA, calponin, NF-κB, and so on in the cells. The content of TNF-α, IL-1β, IL-6, and IL-8 in the cell culture supernatant was checked by ELISA. MTT, Transwell, and flow cytometry were used to detect cell proliferation, migration, and apoptosis. Further, the targeting relations between lncRNA-NEAT1 and miR-128 were evaluated by the dual-luciferase reporter assay.

RESULT

In the sputum of children with bronchial asthma, lncRNA-NEAT1 was significantly upregulated while miR-128 was rapidly downregulated. Besides, lncRNA-NEAT1 and miR-128 were competitively combined and, for their expression, negatively correlated.

CONCLUSION

lncRNA-NEAT1 sponges miR-128 to boost PDGF-BB-induced inflammatory reaction and phenotypic transformation of ASMCs to aggravate the occurrence and development of childhood bronchial asthma.

MicroRNAs: Potential biomarkers for reproduction, diagnosis, prognosis, and therapeutic in domestic animals

MicroRNA (miRNAs) are small non-coding RNA molecules involved in a wide range of biological processes through the post-transcriptional regulation of gene expression. Most studies evaluated microRNA expression in human, and despite fewer studies in veterinary medicine, this topic is one of the most exciting areas of modern veterinary medicine. miRNAs showed to be part of the pathogenesis of diseases and reproduction physiology in animals, making them biomarkers candidates. This review provides an overview of the current knowledge regarding miRNAs' role in reproduction and animal diseases, diagnostic and therapy.

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.

Fusing Multiple Biological Networks to Effectively Predict miRNA-disease Associations

Background:

MicroRNAs (miRNAs) are a class of endogenous non-coding RNAs with about 22 nucleotides, and they play a significant role in a variety of complex biological processes. Many researches have shown that miRNAs are closely related to human diseases. Although the biological experiments are reliable in identifying miRNA-disease associations, they are timeconsuming and costly.

Objective:

Thus, computational methods are urgently needed to effectively predict miRNA-disease associations.

Methods:

In this paper, we proposed a novel method, BIRWMDA, based on a bi-random walk model to predict miRNA-disease associations. Specifically, in BIRWMDA, the similarity network fusion algorithm is used to combine the multiple similarity matrices to obtain a miRNA-miRNA similarity matrix and a disease-disease similarity matrix, then the miRNA-disease associations were predicted by the bi-random walk model.

Results:

To evaluate the performance of BIRWMDA, we ran the leave-one-out cross-validation and 5-fold cross-validation, and their corresponding AUCs were 0.9303 and 0.9223 ± 0.00067, respectively. To further demonstrate the effectiveness of the BIRWMDA, from the perspective of exploring disease-related miRNAs, we conducted three case studies of breast neoplasms, prostate neoplasms and gastric neoplasms, where 48, 50 and 50 out of the top 50 predicted miRNAs were confirmed by literature, respectively. From the perspective of exploring miRNA-related diseases, we conducted two case studies of hsa-mir-21 and hsa-mir-155, where 7 and 5 out of the top 10 predicted diseases were confirmed by literatures, respectively.

Conclusion:

The fusion of multiple biological networks could effectively predict miRNA-diseases associations. We expected BIRWMDA to serve as a biological tool for mining potential miRNAdisease associations.

Recent updates on the role of extracellular vesicles in the pathogenesis of allergic asthma

Asthma is a chronic inflammatory disease of the airway diagnosed with different endotypes and phenotypes, characterized by airway obstruction in response to allergens, bacterial/viral infections, or pollutants. Several cell types such as the airway epithelial cells, mesenchymal stem cells and different immune cells including dendritic cells (DCs), T and B cells and mast cells play an essential role during the pathobiology of asthma. Extracellular vesicles (EVs) are membranous nanovesicles produced by every cell type that facilitates intercellular communications. EVs contain heterogeneous cargos that primarily depend on the composition or cell type of origin and they can alter the physiological state of the target cells. EVs encompass a wide variety of proteins including Tetraspanins, MHC classes I and II, co-stimulatory molecules, nucleic acids such as RNA, miRNA, piRNA, circRNA, and lipids like ceramides and sphingolipids. Recent literature indicates that EVs play a pivotal role in the pathophysiology of allergic asthma and may potentially be used as a novel biomarker to determine endotypes and phenotypes in severe asthmatics. Based on the prior reports, we speculate that regulation of EVs biogenesis and release might be under the control of circadian rhythms. Thus, circadian rhythms may influence the composition of the EVs, which alter the microenvironment that results in the induction of an immune-inflammatory response to various environmental insults or allergens such as air pollutants, ozone, diesel exhaust particles, pollens, outdoor molds, environmental tobacco smoke, etc. In this mini-review, we summarize the recent updates on the novel role of EVs in the pathogenesis of asthma, and highlight the link between circadian rhythms and EVs that may be important to identify molecular mechanisms to target during the pathogenesis of chronic inflammatory lung disease such as asthma.

Extracellular Vesicles and Asthma-More Than Just a Co-Existence

Extracellular vesicles (EVs) are membranous structures, which are secreted by almost every cell type analyzed so far. In addition to their importance for cell-cell communication under physiological conditions, EVs are also released during pathogenesis and mechanistically contribute to this process. Here we summarize their functional relevance in asthma, one of the most common chronic non-communicable diseases. Asthma is a complex persistent inflammatory disorder of the airways characterized by reversible airflow obstruction and, from a long-term perspective, airway remodeling. Overall, mechanistic studies summarized here indicate the importance of different subtypes of EVs and their variable cargoes in the functioning of the pathways underlying asthma, and show some interesting potential for the development of future therapeutic interventions. Association studies in turn demonstrate a good diagnostic potential of EVs in asthma.

Baicalin regulates the development of pediatric asthma via upregulating microRNA-103 and mediating the TLR4/NF-κB pathway

Pediatric asthma seriously endangers the well-being and health of children worldwide. Baicalin (BA) protects against diverse disorders, including asthma. Therefore, this study explored the mechanism of BA in pediatric asthma. The ovalbumin (OVA)-induced asthmatic mouse model was established to evaluate BA efficacy from aspects of oxidative stress, inflammation, blood cells in bronchoalveolar lavage fluid (BALF) and collagen deposition. Differentially expressed microRNAs (miRs) in BA-treated mice were analyzed. Effects of BA on PDGF-BB-induced smooth muscle cells (SMCs) were assessed. miR downstream mRNA and the related pathway were predicted and verified, and their effects on asthmatic mice were evaluated. BA effectively reversed OVA-induced oxidative stress and inflammation, as well as decreased the number of total cells, eosinophils and neutrophils in BALF, and collagen deposition. miR-103 was significantly upregulated after BA treatment. BA inhibited the abnormal proliferation of PDGF-BB-induced SMCs, which was prevented by miR-103 knockdown. miR-103 targeted TLR4 and regulated the extent of NF-κB phosphorylation. In vivo, miR-103 inhibition weakened the alleviating effects of BA on asthma, which was then reversed after silencing of TLR4. We highlighted that BA has the potency to halt the pediatric asthma progression via miR-103 upregulation and the TLR4/NF-κB axis inhibition.

Epithelial-Mesenchymal Transition in Atopy: A Mini-Review

Atopic diseases, particularly atopic dermatitis (AD), asthma, and allergic rhinitis (AR) share a common pathogenesis of inflammation and barrier dysfunction. Epithelial to mesenchymal transition (EMT) is a process where epithelial cells take on a migratory mesenchymal phenotype and is essential for normal tissue repair and signal through multiple inflammatory pathways. However, while links between EMT and both asthma and AR have been demonstrated, as we outline in this mini-review, the literature investigating AD and EMT is far less well-elucidated. Furthermore, current studies on EMT and atopy are mostly animal models or ex vivo studies on cell cultures or tissue biopsies. The literature covered in this mini-review on EMT-related barrier dysfunction as a contributor to AD as well as the related (perhaps resultant) atopic diseases indicates a potential for therapeutic targeting and carry treatment implications for topical steroid use and environmental exposure assessments. Further research, particularly in vivo studies, may greatly advance the field and translate into benefit for patients and families.

Immune effects of miRNA and Th17 cells on β-Lg allergy in dietary milk based on mouse model

β-lactoglobulin (β-Lg) allergy in dietary milk seriously affects the use of high-quality milk protein in infants. In order to solve this problem, the expression of miRNA and Th17 cells in milk β-Lg allergic reaction of children's diet was studied. Method: female BALB/c mice aged 5–6 weeks were selected as the subjects and randomly divided into blank group and β-Lg sensitized group, with 10 mice in each group. On the 1st, 7th and 14th day, the mice in the β-Lg sensitized group were intraperitoneally injected with allergen (Freund's adjuvant + β-Lg). Mice in the blank group were given the same amount of normal saline. Blood samples were collected from the eyeballs of mice to determine the number of inflammatory cells. The contents of Th17 related cytokines and transcription factors in spleen were detected by RT-PCR. Results: 1. the number of eosinophils and neutrophils in the β-Lg sensitized group were 15.76/mL and 24.36/mL, respectively, which were significantly higher than those in the blank group (P < 0.05); 2. in the mice of β-Lg sensitized group, the expression of miR-146a and miR-155 was abnormal, the number of Th17 cells was abnormally increased, and the expression levels of IL-17 and RORγt were significantly increased; 3. the abnormal expression of miR-146a and miR-155 in the mice of β-Lg sensitized group was positively correlated with the secretion of Th17 related cytokines, which could be used as one of the biological indexes to evaluate allergic reaction. Conclusion: the number of Thl7 increased abnormally in dietary milk allergy patients. miRNA gene expression and IL-17 expression could be used as one of the biological indicators to evaluate the allergic reaction of β-Lg.

The emerging role of miR-128 in musculoskeletal diseases

MicroRNA-128 (miR-128) is associated with cell proliferation, differentiation, migration, apoptosis, and survival. Genetic analysis studies have demonstrated that miR-128 participates in bone metabolism, which involves bone marrow-derived mesenchymal stem cells, osteoblasts, osteoclasts, and adipocytes. miR-128 also participates in regeneration of skeletal muscles by targeting myoblast-associated proteins. The deregulation of miR-128 could lead to a series of musculoskeletal diseases. In this review, we discuss recent findings of miR-128 in relation to bone metabolism and muscle regeneration to determine its potential therapeutic effects in musculoskeletal diseases, and to propose directions for future research in this significant field.

An Integrative miRNA-mRNA Expression Analysis Reveals Striking Transcriptomic Similarities between Severe Equine Asthma and Specific Asthma Endotypes in Humans

Severe equine asthma is an incurable obstructive respiratory condition affecting 10–15% of horses in temperate climates. Upon exposure to airborne antigens from hay feeding, affected horses show neutrophilic airway inflammation and bronchoconstriction, leading to increased respiratory effort. The resulting implications range from welfare concerns to economic impacts on equestrian sports and horse breeding. Immunological and pathophysiological characteristics of severe equine asthma show important parallels with allergic and severe neutrophilic human asthma. Our study aimed at investigating regulatory networks underlying the pathophysiology of the disease by profiling miRNA and mRNA expression in lung tissue samples from asthmatic horses compared with healthy controls. We sequenced small RNAs and mRNAs from lungs of seven asthmatic horses in exacerbation, five affected horses in remission, and eight healthy control horses. Our comprehensive differential expression analyses, combined with the miRNA–mRNA negative correlation approach, revealed a strong similarity on the transcriptomic level between severe equine asthma and severe neutrophilic asthma in humans, potentially through affecting Th17 cell differentiation. This study also showed that several dysregulated miRNAs and mRNAs are involved in airway remodeling. These results present a starting point for a better transcriptomic understanding of severe equine asthma and its similarities to asthma in humans.

Equine Asthma: Current Understanding and Future Directions

The 2019 Havemeyer Workshop brought together researchers and clinicians to discuss the latest information on Equine Asthma and provide future research directions. Current clinical and molecular asthma phenotypes and endotypes in humans were discussed and compared to asthma phenotypes in horses. The role of infectious and non-infectious causes of equine asthma, genetic factors and proposed disease pathophysiology were reviewed. Diagnostic limitations were evident by the limited number of tests and biomarkers available to field practitioners. The participants emphasized the need for more accessible, standardized diagnostics that would help identify specific phenotypes and endotypes in order to create more targeted treatments or management strategies. One important outcome of the workshop was the creation of the Equine Asthma Group that will facilitate communication between veterinary practice and research communities through published and easily accessible guidelines and foster research collaboration.

Genetics of Equine Respiratory Disease

Genetic factors influence the development of guttural pouch tympany, recurrent laryngeal neuropathy, severe equine asthma, exercise-induced pulmonary hemorrhage, and possibly also some malformations and infectious diseases of the respiratory tract. The current data suggest that most of these diseases are complex, resulting from the interaction between several genes and environmental factors. To date, no specific genes or causative mutations have been identified that would allow the development of practical genetic tests. In the future, genetic profiling panels, based on multiple genetic markers and environmental risk factors, may allow identification of individuals with an increased genetic risk.

Effect of miR-744 on Ameliorating Heart Allograft Rejection in BALB/c Mice Via Regulation of TNFRSF4 Expression in Regulatory T Cells

CD134 (TNFRSF4) is a member of the TNFR superfamily, which is specifically expressed on T cells. Previous studies have shown that blocking of CD134L-CD134 interaction reduces the percentage of activated T cells and prevents effector T cell-mediated graft rejection in heart transplantation. However, the role of microRNA-regulated inhibition of the CD134 signal in cardiac transplantation of T-regulatory (Treg) cells is not clear. In this study, we found microRNA 744 (miR-744) agomir administration enhanced the expression levels of miR-744 in CD4⁺CD25⁺ Treg cells from heart transplantation mice. Moreover, miR-744 agomir administration significantly enhanced the expression levels of CD62L and Ki67 in CD4⁺CD25⁺ Treg cells from heart transplantation mice and further enhanced immunosuppressive function of Treg cells following coculture with CD4⁺CD25^- T cells for different ratios. In addition, miR-744 agomir treatment significantly prolonged survival time and reduced rejection response of heart allografts in vivo, which are involved in downregulation of TNFRSF4 expression. These results provided a novel molecular mechanism of ameliorating heart allograft rejection in Treg cells, which could be used in the treatment of heart allograft rejection clinically.

Comparative Review of Asthma in Farmers and Horses

PURPOSE OF REVIEW

Farmers are routinely exposed to organic dusts and aeroallergens that can have adverse respiratory health effects including asthma. Horses are farm-reared large animals with similar exposures and can develop equine asthma syndrome (EAS). This review aims to compare the etiology, pathophysiology, and immunology of asthma in horses compared to farmers and highlights the horse as a potential translational animal model for organic dust-induced asthma in humans.

RECENT FINDINGS

Severe EAS shares many clinical and pathological features with various phenotypes of human asthma including allergic, non-allergic, late onset, and severe asthma. EAS disease features include variable airflow obstruction, cough, airway hyperresponsiveness, airway inflammation/remodeling, neutrophilic infiltrates, excess mucus production, and chronic innate immune activation. Severe EAS is a naturally occurring and biologically relevant, translational animal disease model that could contribute to a more thorough understanding of the environmental and immunologic factors contributing to organic dust-induced asthma in humans.

Identification of potential diagnostic biomarkers for pneumonia caused by adenovirus infection in children by screening serum exosomal microRNAs

Human adenovirus (HAdV) infection causes serious pneumonia in children, leading to significant morbidity and mortality rates. However, diagnostic biomarkers for HAdV‑associated pneumonia are unavailable. Serum microRNAs (miRNAs/miRs) have been recently reported as diagnostic biomarkers for several diseases. The present study performed microRNA sequencing to identify potential biomarkers among serum exosomal miRNAs, with the aim of identifying candidate biomarkers for the diagnosis of pneumonia in adenovirus‑infected children. To validate the biomarker candidates, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to determine the relative expression levels of miRNAs. As there is no endogenous reference RNA for serum miRNAs, pairwise analysis of RT‑qPCR was used in the present study to narrow down the number of biomarker candidates among all the serum exosomal miRNAs to a set of four miRNAs. As a result, the identified miRNAs (namely, miR‑450a‑5p‑miR‑103a‑3p and miR‑103b‑5p‑miR‑98‑5p) from 59 samples were considered as potential diagnostic biomarkers in adenovirus‑infected children. The results indicated that this four miRNA set could distinguish adenovirus‑infected patients from healthy controls. In conclusion, the four exosomal miRNAs identified in the present study could be considered as candidate diagnostic biomarkers for pneumonia in adenovirus‑infected children.

MicroRNA-744 Inhibits Proliferation of Bronchial Epithelial Cells by Regulating Smad3 Pathway via Targeting Transforming Growth Factor-β1 (TGF-β1) in Severe Asthma

BACKGROUND Bronchial epithelial cells proliferation plays a pivotal role in airway remodeling in children with severe asthma. MicroRNAs (miRNAs) have gained great attention for many diseases, including asthma. The purpose of this study was to explore the mechanisms that underlie miR-744 modulating bronchial epithelial cells proliferation in severe asthma in children. MATERIAL AND METHODS Bronchial epithelial cells were isolated from bronchial biopsies of normal controls and asthmatic subjects. miR-744 and transforming growth factor-ß1 (TGF-ß1) expressions were measured by quantitative reverse transcription PCR (qRT-PCR). Proliferating cell nuclear antigen (PCNA), phosphorylation or total of mothers against decapentaplegic homolog3 (Smad3) and production of Smad anchor for receptor activation (SARA) were measured via Western blot analysis. A link between miR-744 and TGF-ß1 was probed by luciferase activity and RNA immunoprecipitation. Cell proliferation was evaluated using the Cell Proliferation Assay Kit. RESULTS Severe asthma showed a significantly elevated cell proliferation rate and reduced abundance of miR-744, which in turn inhibited cell proliferation of bronchial epithelial cells. In particular, TGF-ß1 might be a candidate target of miR-744, and enrichment of miR-744 lowered the expression of TGF-ß1 at mRNA and protein levels. Indeed, overexpression of miR-744 lowered the proliferation rate of bronchial epithelial cells via driving TGF-ß1. Moreover, addition of miR-744 limited phosphorylation of Smad3 but reversed SARA protein abundance by regulating TGF-ß1. CONCLUSIONS The presence of miR-744 repressed bronchial epithelial cells proliferation through mediating the Smad3 pathway by modulating TGF-ß1, providing a promising therapeutic approach for epithelial function in severe asthma.

Equine asthma: Integrative biologic relevance of a recently proposed nomenclature

The term “equine asthma” has been proposed as a unifying descriptor of inflammatory airway disease (IAD), recurrent airway obstruction (RAO), and summer pasture‐associated obstructive airway disease. Whilst the term will increase comprehensibility for both the lay and scientific communities, its biologic relevance must be compared and contrasted to asthma in human medicine, recognizing the limited availability of peer‐reviewed equine‐derived data, which are largely restricted to clinical signs, measures of airway obstruction and inflammation and response to therapy. Such limitations constrain meaningful comparisons with human asthma phenotypes. Suggested minimum inclusion criteria supporting the term asthma, as well as similarities and differences between IAD, RAO, and multiple human asthma phenotypes are discussed. Furthermore, differences between phenotype and severity are described, and typical features for equine asthma subcategories are proposed. Based on shared features, we conclude that mild/moderate (IAD) and severe (RAO) equine asthma are biologically appropriate models for both allergic and non‐allergic human asthma, with RAO (severe equine asthma) also being an appropriate model for late‐onset asthma. With the development of new biologic treatments in humans and the application of more targeted therapeutic approaches in the horse, it would appear appropriate to further investigate the allergic (Th‐2) and non‐allergic (non‐Th‐2) phenotypes of equine asthma. Further research is required to more fully determine the potential clinical utility of phenotype classification.

Precision Medicine in Targeted Therapies for Severe Asthma: Is There Any Place for "Omics" Technology?

According to the current guidelines, severe asthma still represents a controversial topic in terms of definition and management. The introduction of novel biological therapies as a treatment option for severe asthmatic patients paved the way to a personalized approach, which aims at matching the appropriate therapy with the different asthma phenotypes. Traditional asthma phenotypes have been decomposing by an increasing number of asthma subclasses based on functional and physiopathological mechanisms. This is possible thanks to the development and application of different omics technologies. The new asthma classification patterns, particularly concerning severe asthma, include an increasing number of endotypes that have been identified using new omics technologies. The identification of endotypes provides new opportunities for the management of asthma symptoms, but this implies that biological therapies which target inflammatory mediators in the frame of specific patterns of inflammation should be developed. However, the pathway leading to a precision approach in asthma treatment is still at its beginning. The aim of this review is providing a synthetic overview of the current asthma management, with a particular focus on severe asthma, in the light of phenotype and endotype approach, and summarizing the current knowledge about "omics" science and their therapeutic relevance in the field of bronchial asthma.

Downregulation of MicroRNA eca-mir-128 in Seminal Exosomes and Enhanced Expression of CXCL16 in the Stallion Reproductive Tract Are Associated with Long-Term Persistence of Equine Arteritis Virus

Equine arteritis virus (EAV) can establish long-term persistent infection in the reproductive tract of stallions and is shed in the semen. Previous studies showed that long-term persistence is associated with a specific allele of the CXCL16 gene (CXCL16S) and that persistent infection is maintained despite the presence of a local inflammatory and humoral and mucosal antibody responses. In this study, we demonstrated that equine seminal exosomes (SEs) are enriched in a small subset of microRNAs (miRNAs). Most importantly, we demonstrated that long-term EAV persistence is associated with the downregulation of an SE-associated miRNA (eca-mir-128) and with an enhanced expression of CXCL16 in the reproductive tract, a putative target of eca-mir-128. The findings presented here suggest that SE eca-mir-128 is implicated in the regulation of the CXCL16/CXCR6 axis in the reproductive tract of persistently infected stallions, a chemokine axis strongly implicated in EAV persistence. This is a novel finding and warrants further investigation to identify its specific mechanism in modulating the CXCL16/CXCR6 axis in the reproductive tract of the EAV long-term carrier stallion.IMPORTANCE Equine arteritis virus (EAV) has the ability to establish long-term persistent infection in the stallion reproductive tract and to be shed in semen, which jeopardizes its worldwide control. Currently, the molecular mechanisms of viral persistence are being unraveled, and these are essential for the development of effective therapeutics to eliminate persistent infection. Recently, it has been determined that long-term persistence is associated with a specific allele of the CXCL16 gene (CXCL16S) and is maintained despite induction of local inflammatory, humoral, and mucosal antibody responses. This study demonstrated that long-term persistence is associated with the downregulation of seminal exosome miRNA eca-mir-128 and enhanced expression of its putative target, CXCL16, in the reproductive tract. For the first time, this study suggests complex interactions between eca-mir-128 and cellular elements at the site of EAV persistence and implicates this miRNA in the regulation of the CXCL16/CXCR6 axis in the reproductive tract during long-term persistence.