Smoking alters hydroxyprostaglandin dehydrogenase expression in fetal membranes

Introduction: The way in which tobacco smoking increases the risk of preterm labor remains uncertain. Altered prostaglandin metabolism is one potential mechanism. Methods: Proteins in fetal membrane samples (amniochoriodecidua) from 20 women were relatively quantified using Tandem Mass Tagging nano-liquid chromatography mass spectrometry. Results: Prostaglandin synthases and two enzymes involved in prostaglandin degradation, hydroxyprostaglandin dehydrogenase (HPGD) and CBR1, were detected by the mass spectrometer. The expression of HPGD was significantly lower in smokers relative to non-smokers (0.43 fold, p = 0.016). There was no effect of labor, inflammatory status or gestational age on the HPGD levels. Discussion: We describe for the first time an association between maternal smoking and HPGD expression. We propose that reduced expression of HPGD is one mechanism through which smoking may contribute to preterm labor. Lower levels of this enzyme, key to metabolising prostaglandins, may result in higher levels of prostaglandins and therefore precipitate labor prematurely.