Impact of maternal smoking onmRNA expression in placental tissue : - a systematic literature survey

Introduction: Maternal smoking during pregnancy is becoming less common. However, it is still a significant predictor of adverse outcomes. Smoking during pregnancy has been associated with impaired fetal development and growth. The purpose of this systematic litera-ture study was to describe the placental molecular targets that have been identified as poten-tially affected by maternal smoking, with emphasis on alterations in placental gene expres-sion. Objective: To decribe the impact of maternal smoking on mRNA expression in placental tissue. Design: Systematic literature survey Methods: We searched for studies in PubMed. To be included in the survey the studies had to be written in English and asses mRNA expression in isolated placental cells, animal, or hu-man placental tissue in conjunction with exposure to some or all elements of tobacco smoke. Out of 54 studies found, 14 met the eligibility criteria. One reviewer assessed the eligibility and quality of the studies. Results: Eight studies investigated human placental tissue, two investigated rodent placental tissue, and five studies investigated isolated placental cells. Two studies profiled the global gene expression, while the other studies examined the expression of the CYP genes, or genes involved in angiogenic regulation, cellular proliferation, or amino acid metabolism and transport in relation to cigarette smoking. Discussion: We conclude that even though the influence of cigarette smoking on gene expres-sion in placenta has only been investigated in a few studies, they all found transcriptional al-terations in relation to smoke exposure. Future investigations are necessary for the examina-tion of how these changes may impact fetal development and growth