Effects of AntagomiRs on Different Lung Diseases in Human, Cellular, and Animal Models

Murdaca, Giuseppe; Tonacci, Alessandro; Negrini, Simone; Greco, Monica; Borro, Matteo; Puppo, Francesco; Gangemi, Sebastiano

ensively studied. MiRNAs have proven to play a crucial role among lung cancer, pulmonary fibrosis, tuberculosis (TBC) infection, and bronchial hypersensitivity, thus including chronic obstructive pulmonary disease (COPD) and asthma. The oncogenic effect of several miRNAs has been recently ruled out. Herein, a study of our group recently identified for the first time new mechanisms, supporting the crucial role of cigarette smoke-induced miR-21 expression in the amplification of inflammatory responses and in tumorigenesis processes within the airways [11] . COPD is a complex disease with a high rate of morbidity and mortality, especially in Western countries. Disease exacerbations and the associated hospitalizations often represent a considerable expense at a socio-economic level. Reduced lung function predicts mortality and is key to the diagnosis of COPD. Shrine et al. [12] conducted a genome-wide associated study in order to highlight new genetic mechanisms in order to improve future preventive and therapeutic strategies for COPD. More recently, many authors investigated miRNAs expression in COPD, noticing that wide networks composed of miRNA and messenger RNA (mRNAs) cooperate in COPD pathogenesis [13] . Moreover, Faiz et al. [14] investigated whether miRNA expression was modulated by inhaled corticosteroid (ICS) treatment and identified miR-320d as a novel mediator of ICS, regulating the pro-inflammatory response of the airway epithelium. Nowadays, among chronic inflammatory lung diseases, asthma is one of the most prevalent. Pathological mechanisms rely on activation of mast cells and eosinophils and dysregulation of Th 2 response. Asthmatic patients often have a strong genetic background, however recent studies demonstrated the role of epigenetic factors such as miRNAs [15] . Gold standard therapies for asthma control include inhaled β-agonists, both short and long acting, and steroids. On this background, Yu at al. [16] recently demonstrated that a specific miRNA, miR-16, may be used as a predictive biomarker of therapeutic response in asthma, thus, suggesting the role of miRNAs not only upon disease physiopathology but also upon drug response. MiRNAs have shown to have an effect also upon pulmonary arterial hypertension (PAH). PAH is a complex disease with different clinical manifestations and high genetic variability. ESC/ERS Guidelines outlined some of the most frequently involved genetic factors such as nuclear factor of activated T cells (NFAT), hypoxia-inducible factor 1α (HIF-1α), and signal transducer and activator of transcription 3 (STAT3) [17] . New research showed that miRNAs may play a crucial role in vascular remodeling, thus inhibiting or promoting pulmonary As shown in Table 1-Table 5 , the vast majority of them included research carried out on cell lines and on animals, whereas only a few (20, corresponding to 29.4%) investigated the selected topic on humans. As expected, the condition most widely investigated was lung cancer (21/68), followed by pulmonary hypertension (7/68). All of the selected papers took into account the efficacy of the antagomiR treatment on the various diseases, whereas safety was rarely investigated (only in two cases out of 68). Overall, the use of antagomiR was seen to be efficient in downregulating the specific miRNA they are conceived for, with quite similar results either in vivo and in vitro and independently from the disease and the cell line they are used for. Overall, the usefulnes