RT Journal Article SR Electronic T1 MiR-320c regulates SERPINA1 expression and is associated with pulmonary disease in alpha-1-antitrypsin deficiency JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA3406 DO 10.1183/13993003.congress-2016.PA3406 VO 48 IS suppl 60 A1 Nerea Matamala A1 Álvaro Otero A1 Irene Vázquez A1 Diana Retana A1 Antonio Muñoz-Callejas A1 Taiomara Fernández-González A1 Beatriz Lara A1 María Teresa Martínez A1 Alpha1-Antitrypsin Deficiency Spanish Registry A1 Beatriz Martínez-Delgado YR 2016 UL http://erj.ersjournals.com/content/48/suppl_60/PA3406.abstract AB Alpha-1 antitrypsin deficiency (AATD) is a hereditary disorder caused by mutations in the SERPINA1 gene, and is characterized by lung emphysema and liver disease. AATD shows a high degree of phenotypic variability, which suggests that unknown genetic factors may influence disease severity. Since microRNAs (miRNAs) are involved in the pathogenesis of several human diseases, we investigated whether SERPINA1 gene could be regulated by these short single-stranded RNA molecules. In silico prediction revealed that miR-320c binds to the 3'UTR of SERPINA1 gene. We confirmed these results by luciferase reporter assay, and this mechanism was absent when a polymorphism was present in the target binding site of the gene. In addition, in vitro expression of miR-320c in HL60 cells led to downregulation of SERPINA1 gene. We further analyzed miR-320c expression in the blood of 35 patients with AATD and showed that this miRNA was overexpressed in patients with lung disease. Our results indicate that miR-320c regulates the expression of SERPINA1 gene, and its overexpression in blood could contribute to the pathogenesis of AATD.