Emerging role of MicroRNAs in allergic diseases

Abstract

The prevalence of allergic diseases has risen at alarming rates, and a recent study identified allergic sensitization in 40% of school children worldwide [1] . Allergic diseases affect a wide variety of organs, including eyes (allergic conjunctivitis), nose (allergic rhinitis), airway (asthma), gastrointestinal tract (food allergies and eosinophilic esophagitis), and skin (atopic dermatitis). Common gaps among these diseases are the lack of understanding of the molecular basis of pathogenesis (particularly how and why inflammation is de-regulated), and the crucial need to identify biomarkers to better diagnose and characterize these diseases. Along these lines, microRNAs (miRNAs) have emerged as central regulators of many processes (including inflammation) and potentially useful biomarkers (in large part because they are found in all biofluids). As a result, it is not surprising that these two fields have intersected, and a better understanding of how miRNAs regulate allergic inflammation could lead to novel therapies and diagnostic tools.We are just beginning to understand the roles of miRNAs in allergic diseases. This special issue highlights the emerging roles of miRNAs in across a spectrum of allergic disease that affects different organ systems, and demonstrates their potential application to understanding, treating, and diagnosing human disease. The article by Weidner et al. [2] reviews the progress in our understanding of miRNAs in asthma, and the evolution of research from mouse to humans. This review captures the translational research potential of miRNAs in asthma, and underscores the need for both mouse and human studies in mechanistic miRNA studies. In particular, ablation of pathogenic miRNAs (such as miR-155) in mice has demonstrated their crucial role in pathogenesis of allergic inflammation, and their conserved role in human disease is now becoming evident. In work from our lab, Zhang et al. [3] present a primary research article that builds on the mechanistic studies to show how miRNAs can be used to better characterize asthma. We now understand that asthma is a syndrome that is comprised of many distinct phenotypes, which have different molecular