miRNA expression in tracheal aspirates

Extreme preterm infants are a growing population in neonatal intensive care units who carry a high mortality and morbidity. Multiple factors play a role in preterm birth, resulting in major impact on organogenesis leading to complications including bronchopulmonary dysplasia (BPD). The goal of this study was to identify biomarker signatures associated with prematurity and BPD. We analyzed miRNA and mRNA profiles in tracheal aspirates (TAs) from 51 infants receiving invasive mechanical ventilation. 25 infants were extremely preterm and diagnosed with BPD, and 26 were term babies receiving invasive mechanical ventilation for elective procedures. We found specific mRNA-miRNA signatures in TAs that may serve as biomarkers for BPD pathogenesis, a consequence of extreme prematurity. We extracted RNA from 0.5 mL of tracheal aspirates from control neonates and premature babies with bronchopulmonary dysplasia using the Plasma/Serum RNA Purification Kit. The expression of 1,066 human miRNAs was quantified using the Human miRNome miScript® miRNA PCR Array (QIAGEN, MIHS-3216Z). Results (Ct values) were normalized to global means, and fold changes were calculated using the 2-ΔΔCT method. control: 2,6,7,10,11,14,17,18,23,24,26,28,30,32,33,34,36,38,40,41,42,43,44,46,49,50 BPD: 1,3,4,5,8,9,12,13,15,16,19,20,21,22,25,27,29,31,35,37,39,45,47,48,51