Maternal and Neonatal Exposure to Environmental Tobacco Smoke Targets Pro-Inflammatory Genes in Neonatal Arteries

Maternal mainstream tobacco smoking is known to have adverse outcomes on fetal respiratory function; however, no data is currently available on the effects of passive exposure to tobacco smoking and environmental tobacco smoke (ETS) on fetal systemic arterial structure and function. Eight pregnant rhesus macaque monkeys were studied at the California Regional Primate Research Center breeding colony. The estimated gestational age for each dam was established by sonography performed before gestational day 40. Two inhalation chambers were used, each with an air capacity of 3.5 m(3), and each housed two dams. Aged and diluted sidestream smoke was used as a surrogate for ETS. Exposure to ETS (1 mg/m(3)) occurred for 6 h/day, 5 days/week, beginning on gestational day 100. All dams were allowed to give birth spontaneously and then ETS exposure continued 70-80 days postnatally with the chamber containing both the mother and infant. Carotid arteries from four control (C) and four ETS-treated newborns were analyzed for mRNA by gene macroarray and for protein by Western blotting. A total of 588 cardiovascular genes were studied. Four genes were upregulated by ETS compared to C, and nine genes were downregulated (≥2-fold change). Three genes were selected for further study. Following ETS exposure, neonatal carotid arteries of non-human primates manifested evidence of inflammation with increased gene and protein expression of LFA-1 and RANTES, proteins that are recognized to be important in vascular adhesion and inflammation, and downregulation of expression for the receptor for VEGF, which has a key role in angiogenesis. Prenatal and postnatal exposure to ETS increases expression of pro-inflammatory genes and may be responsible for early arterial vascular remodeling that is predisposing to a subsequent vascular disease.