Open AccessSingle nucleotide polymorphisms in surfactant protein A1 are not associated with a lack of responsiveness to antenatal steroid therapy in a pregnant sheep model
Author(s) -
Takahashi Tsukasa,
Takahashi Yuki,
Fee Erin L.,
Usuda Haruo,
Furfaro Lucy,
Newnham John P.,
Jobe Alan H.,
Kemp Matthew W.
Publication year - 2022
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.15477
Subject(s) - medicine , single nucleotide polymorphism , ventilation (architecture) , lung , mechanical ventilation , respiratory distress , antenatal steroid , andrology , endocrinology , biology , anesthesia , bioinformatics , gestational age , pregnancy , genotype , biochemistry , genetics , gene , mechanical engineering , engineering
Treatment with antenatal steroids (ANS) is standard practice for reducing the risk of respiratory distress in the preterm infant. Despite clear overall benefits when appropriately administered, many fetuses fail to derive benefit from ANS therapies. In standardized experiments using a pregnant sheep model, we have demonstrated that around 40% of ANS‐exposed lambs did not have functional lung maturation significantly different from that of saline‐treated controls. Surfactant protein A is known to play an important role in lung function. In this genotyping study, we investigated the potential correlation between polymorphisms in SFTPA1 , messenger RNA and protein levels, and ventilation outcomes in animals treated with ANS. 45 preterm lambs were delivered 48 h after initial ANS therapy and 44 lambs were delivered 8 days after initial ANS therapy. The lambs were ventilated for 30 min after delivery. SFTPA1 mRNA expression in lung tissue was not correlated with arterial blood PaCO 2 values at 30 min of ventilation in lambs delivered 48 h after treatment. SFTPA1 protein in lung tissue was significantly correlated with PaCO 2 at 30 min of ventilation in lambs ventilated both 48 h and 8 days after ANS treatment. Six different single nucleotide polymorphisms (SNPs) in the Ovis aries SFTPA1 sequence were detected by Sanger Sequencing. No individual SNPs or SNP haplotypes correlated with alterations in PaCO 2 at 30 min of ventilation or SFTPA1 protein levels in the lung. For the subset of animals analyzed in the present study, variable lung maturation responses to ANS therapy were not associated with mutations in SFTPA1 .