Effect of neuromedin U on allergic airway inflammation in an asthma model

Construction and validation of an immune gene-based model for diagnosis and risk prediction of severe asthma

OBJECTIVE

Severe asthma (SA) is a serious disease with limited treatment options, which is closely linked to immune dysfunction. Therefore, immune-associated biomarkers may diagnose SA and offer therapeutic targets for SA.

METHODS

The gene expression profiles of SA patients and matched controls were from the National Center for Biotechnology Information database. Immune genes were downloaded from the ImmPort database. After screening for differentially expressed genes (DEGs) between SA patients and controls, and identifying gene modules highly associated with SA, immune-related DEGs were obtained. Then, protein-protein interaction analysis, Cytoscape software and receiver operating characteristic (ROC) curves were used to identify hub genes. Next, the relationship between hub genes and immune cells was explored, and single-sample gene set enrichment analysis (ssGSEA) was applied to conduct pathway enrichment analyses. Finally, the Least Absolute Shrinkage and Selection Operator (LASSO) combined with ROC analysis were used to confirm the diagnostic value of the hub genes.

RESULTS

Forty immune-related DEGs were obtained, and RNASE3, CAMP and LTF were determined as hub genes. The hub genes were closely associated with immune cells, and ssGSEA showed that lysosome was associated with high expressions of the hub genes, while primary immunodeficiency was related to low expressions of the hub genes. LASSO combined with ROC analysis confirmed the immune gene-based model (RNASE3, CAMP, LTF, and CD79A) could distinguish SA patients from healthy individuals with high sensitivity.

CONCLUSIONS

RNASE3, CAMP, LTF, and CD79A could act as diagnostic markers for SA, providing a theoretical basis for developing diagnostic targets for SA.

A genome-wide association study implicates the pleiotropic effect of NMUR2 on asthma and COPD

Asthma and chronic obstructive pulmonary disease (COPD) are two distinct diseases that are associated with chronic inflammation. They share common features in terms of their advanced stages and genetic factors. This study aimed to identify novel genes underlying both asthma and COPD using genome-wide association study (GWAS) to differentiate between the two diseases. We performed a GWAS of asthma and COPD in 7828 Koreans from three hospitals. In addition, we investigated genetic correlations. The UK Biobank dataset was used for the replication studies. We found that rs2961757, located near neuromedin U receptor 2 (NMUR2) on chromosome 5, was genome-wide significant ([Formula: see text] = 0.44, P-value_Asthma-COPD = 3.41 × 10^-8), and significant results were replicated with the UK Biobank data ([Formula: see text] = 0.04, P-value_Asthma-COPD = 0.0431). A positive genetic correlation was observed between asthma and COPD (39.8% in the Korean dataset and 49.8% in the UK Biobank dataset). In this study, 40-45% of the genetic effects were common to asthma and COPD. Moreover, NMUR2 increases the risk of asthma development and suppresses COPD development. This indicates that NMUR2 allows for better differentiation of both diseases, which can facilitate tailored medical therapy.

Neuronal-Immune Cell Units in Allergic Inflammation in the Nose

Immune cells and immune-derived molecules, endocrine glands and hormones, the nervous system and neuro molecules form the combined tridirectional neuroimmune network, which plays a significant role in the communication pathways and regulation at the level of the whole organism and local levels, in both healthy persons and patients with allergic rhinitis based on an allergic inflammatory process. This review focuses on a new research paradigm devoted to neuronal-immune cell units, which are involved in allergic inflammation in the nose and neuroimmune control of the nasal mucociliary immunologically active epithelial barrier. The categorization, cellular sources of neurotransmitters and neuropeptides, and their prevalent profiles in constituting allergen tolerance maintenance or its breakdown are discussed. Novel data on the functional structure of the nasal epithelium based on a transcriptomic technology, single-cell RNA-sequencing results, are considered in terms of neuroimmune regulation. Notably, the research of pathogenesis and therapy for atopic allergic diseases, including recently identified local forms, from the viewpoint of the tridirectional interaction of the neuroimmune network and discrete neuronal-immune cell units is at the cutting-edge.

Neuromedins NMU and NMS: An Updated Overview of Their Functions

More than 35 years have passed since the identification of neuromedin U (NMU). Dozens of publications have been devoted to its physiological role in the organism, which have provided insight into its occurrence in the body, its synthesis and mechanism of action at the cellular level. Two G protein-coupled receptors (GPCRs) have been identified, with NMUR1 distributed mainly peripherally and NMUR2 predominantly centrally. Recognition of the role of NMU in the control of energy homeostasis of the body has greatly increased interest in this neuromedin. In 2005 a second, structurally related peptide, neuromedin S (NMS) was identified. The expression of NMS is more restricted, it is predominantly found in the central nervous system. In recent years, further peptides related to NMU and NMS have been identified. These are neuromedin U precursor related peptide (NURP) and neuromedin S precursor related peptide (NSRP), which also exert biological effects without acting via NMUR1, or NMUR2. This observation suggests the presence of another, as yet unrecognized receptor. Another unresolved issue within the NMU/NMS system is the differences in the effects of various NMU isoforms on diverse cell lines. It seems that development of highly specific NMUR1 and NMUR2 receptor antagonists would allow for a more detailed understanding of the mechanisms of action of NMU/NMS and related peptides in the body. They could form the basis for attempts to use such compounds in the treatment of disorders, for example, metabolic disorders, circadian rhythm, stress, etc.