Gene expression in fetal aortic arteries of C57BL/6 mice with Nod1 stimulation

We previously demonstrated that an innate immune receptor, the nucleotide-binding oligomerization domain-1 (Nod1), was involved in the vascular disease in young and adult mice. However, little is known about the role of Nod1 signaling in fetuses. We administered FK565, one of the Nod1 ligands, to pregnant C57BL/6 mice and examined its effect in the fetuses. Nod1 stimulation increased levels of cytokines in the pregnant mice, placentae and fetuses. We found that FK565 which was administered to the pregnant mice transferred to the fetuses through the placentae, and exerted its effects on fetuses in vivo. Nod1 was abundantly expressed in the arteries, and the vascular tissues predominantly produced CCL2 and IL-6 in response to FK565 compared with other fetal tissues. FK565 induced up-regulation of genes associated with immune response, inflammation and apoptosis in fetal vascular tissues. To explore the molecular mechanism of direct responses of fetal vascular system by Nod1 ligand in vivo, Nod1 -/- females were mated with Nod1 +/- males , and pregnant mice were subcutaneously injected with 500 μg FK565 at E18.5. Six hours later, aortic arteries of the fetuses were sterilely separated. Microarray analysis was performed on aortic arteries from Nod1 +/- (n=3) and Nod1 -/- (n=3) littermate fetuses.