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Publication Date

5-2023

Abstract

Background: Synthetic glucocorticoids (sGC) are used to prevent bronchopulmonary dysplasia (BPD) in preterm infants. Ciclesonide (CIC), a sGC pro-drug, is FDA-approved for treatment of children with asthma. We reported that in comparison with dexamethasone, CIC does not affect brain development when used in the neonatal period. We have also shown that LPS, derived from gram negative bacteria, causes lung endothelial cell (EC) immune activation that contributes to sepsis-induced acute lung injury (ALI). In this study, we hypothesized that LPS-induced endothelial inflammation and ALI will be inhibited by CIC.

Objectives: a) Investigate the mechanisms by which CIC inhibits lung EC inflammation and injury, and b) Test whether CIC can repress systemic LPS-induced acute inflammation in neonatal mice.

Methods: Primary human pulmonary microvascular endothelial cells (HPMEC, ScienCell) incubated with 0.1uM CIC for 6hrs followed by treatment with 100ng/mL LPS were used to measure inflammation by western blotting, 2D angiogenesis, and qRT-PCR. Neonatal mice were i.p injected with 2mg/kg LPS, with subsequent i.p CIC (2.5mg/kg) injections at +2- and +26hrs. At 48hrs post LPS injection, bronchoalveolar lavage (BAL) was done to probe inflammatory cell influx and alveolar edema.

Results: CIC-induced expression of CES1 and CES2, enzymes that convert CIC to its active metabolite des-CIC, as well as the glucocorticoid receptor (GR) target genes FAM107A and FKBP5 (Fig. 1A-B) in HPMEC. LPS-induced expression of ICAM1, IL1β, and iNOS was suppressed by CIC (Fig. 1C-D). LPS-induced Toll Like receptor 4 signaling evidenced by (p)IKKβ and (p)p65 was attenuated by CIC (Fig. 1E). Cell viability decreased with LPS and was restored with CIC (Fig. 2A). LPS-induced VEGF and delta like 4 (regulators of angiogenesis) expression and aberrant 2D angiogenesis in HPMEC were suppressed by CIC (Figs. 2B-E). In our neonatal sepsis mouse model, CIC attenuated the influx of immune cells and vascular leakage seen 48hrs after LPS in the lung (Fig. 3A-B).

Conclusions: CIC protects against LPS-induced inflammation and EC injury in HPMEC. Sepsis (LPS)-induced lung inflammatory cell influx and vascular permeability was inhibited by CIC in our neonatal mice. Further animal studies will determine whether sepsis-induced neonatal ALI and alveolar remodeling is mitigated by CIC.

Document Type

Poster

Ciclesonide protects against LPS-induced lung endothelial inflammation and acute lung injury

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