Surfactant-assisted distal pulmonary distribution of Budesonide revealed by mass spectrometry imaging

13openInternationalBothDirect lung administration of budesonide in combination with surfactant reduces the incidence of bronchopulmonary dysplasia. Although the therapy is currently undergoing clinical development, the lung distribution of budesonide throughout the premature neonatal lung has not yet been investigated. Here, we applied mass spectrometry imaging (MSI) to investigate the surfactant-assisted distal lung distribution of budesonide. Unlabeled budesonide was either delivered using saline as a vehicle (n = 5) or in combination with a standard dose of the porcine surfactant Poractant alfa (n = 5). These lambs were ventilated for one minute, and then the lungs were extracted for MSI analysis. Another group of lambs (n = 5) received the combination of budesonide and Poractant alfa, followed by two hours of mechanical ventilation. MSI enabled the label-free detection and visualization of both budesonide and the essential constituent of Poractant alfa, the porcine surfactant protein C (SP-C). 2D ion intensity images revealed a non-uniform distribution of budesonide with saline, which appeared clustered in clumps. In contrast, the combination therapy showed a more homogeneous distribution of budesonide throughout the sample, with more budesonide distributed towards the lung periphery. We found similar distribution patterns for the SP-C and budesonide in consecutive lung tissue sections, indicating that budesonide was transported across the lungs associated with the exogenous surfactant. After two hours of mechanical ventilation, the budesonide intensity signal in the 2D ion intensity maps dropped dramatically, suggesting a rapid lung clearance and highlighting the relevance of achieving a uniform surfactant-assisted lung distribution of budesonide early after delivery to maximize the anti-inflammatory and maturational effects throughout the lungopenZecchi, Riccardo; Franceschi, Pietro; Tigli, Laura; Pioselli, Barbara; Mileo, Valentina; Murgia, Xabier; Salomone, Fabrizio; Pieraccini, Giuseppe; Usada, Haruo; Schmidt, Augusto F; Hillman, Noah H.; Kemp, Matthew W.; Jobe, Alan H.Zecchi, R.; Franceschi, P.; Tigli, L.; Pioselli, B.; Mileo, V.; Murgia, X.; Salomone, F.; Pieraccini, G.; Usada, H.; Schmidt, A.F.; Hillman, N.H.; Kemp, M.W.; Jobe, A.H

Intestinal Goblet Cell Loss during Chorioamnionitis in Fetal Lambs: Mechanistic Insights and Postnatal Implications

Chorioamnionitis, an important cause of preterm birth, is linked to necrotizing enterocolitis (NEC). NEC is characterized by a disrupted mucus barrier, goblet cell loss, and endoplasmic reticulum (ER) stress of the intestinal epithelium. These findings prompted us to investigate the mechanisms underlying goblet cell alterations over time in an ovine chorioamnionitis model. Fetal lambs were intra-amniotically (IA) exposed to lipopolysaccharides (LPS) for 5, 12, or 24 h, or 2, 4, 8, or 15 d before premature delivery at 125 d gestational age (GA). Gut inflammation, the number, distribution, and differentiation of goblet cells, ER stress, and apoptosis were measured. We found a biphasic reduction in goblet cell numbers 24 h-2 d after, and 15 d after IA LPS exposure. The second decrease of goblet cell numbers was preceded by intestinal inflammation, apoptosis, and crypt ER stress, and increased SAM-pointed domain-containing ETS transcription factor (SPDEF)-positive cell counts. Our combined findings indicated that ER stress drives apoptosis of maturating goblet cells during chorioamnionitis, ultimately reducing goblet cell numbers. As similar changes have been described in patients suffering from NEC, these findings are considered to be clinically important for understanding the predecessors of NEC, and targeting ER stress in this context is interesting for future therapeutics