Porphyromonas gingivalis outer membrane vesicles shape trophoblast cell metabolism impairing functions associated to adverse pregnancy outcome.

Periodontitis is proposed as a risk factor for preterm delivery, fetal growth restriction, and preeclampsia with severe consequences for maternal and neonatal health, but the biological mechanisms involved are elusive. Porphyromonas gingivalis gain access to the placental bed and impair trophoblast cell function, as assessed in murine and human pregnancy, suggesting a pathogenic role in adverse pregnancy and neonatal outcomes. P. gingivalis releases outer membrane vesicles (P. gingivalis OMV) during growth that spread to distant tissues and are internalized in host cells as described in metabolic, neurological, and vascular systemic diseases. Here we tested the hypothesis that P. gingivalis OMV internalized in trophoblast cells disrupt their metabolism leading to trophoblast and placenta dysfunction and adverse pregnancy outcomes. An in vitro design with human trophoblast cells incubated with P. gingivalis OMV was used together with ex vivo and in vivo approaches in pregnant mice treated with P. gingivalis OMV. P. gingivalis OMV modulated human trophoblast cell metabolism by reducing glycolytic pathways and decreasing total reactive oxygen species with sustained mitochondrial activity. Metabolic changes induced by P. gingivalis OMV did not compromise cell viability; instead, it turned trophoblast cells into a metabolic resting state where central functions such as migration and invasion were reduced. The effects of P. gingivalis OMV on human trophoblast cells were corroborated ex vivo in mouse whole placenta and in vivo in pregnant mice: P. gingivalis OMV reduced glycolytic pathways in the placenta and led to lower placental and fetal weight gain in vivo with reduced placental expression of the glucose transporter GLUT1. The present results point to OMV as a key component of P. gingivalis involved in adverse pregnancy outcomes, and even more, unveil a metabolic cue in the deleterious effect of P. gingivalis OMV on trophoblast cells and mouse pregnancy, providing new clues to understand pathogenic mechanisms in pregnancy complications and other systemic diseases.

Vasoactive intestinal peptide deficiency promotes ovarian dysfunction associated to a proinflammatory microenvironment reminiscent of premature aging.

Complex immune regulation during pregnancy is required to ensure a successful pregnancy outcome. Vasoactive intestinal peptide (VIP) has local immunoregulatory effects on the ovary, uterus and maternal-fetal interface that favor a tolerogenic maternal microenvironment. Since the VIP Knockout (KO) mice are subfertile, we investigated the mechanisms underlying the effects of VIP deficiency on ovarian physiology and immune homeostasis. Therefore, we studied VIP KO, deficient (HT) and wild type (WT) female mice in estrus at 3 or 8 months of age. Young KO mice showed abnormal cycle timing and regularity associated with dysfunctional ovaries. Ovaries presented higher number of atretic follicles and reduced number of corpora lutea leading to a lower ovulation rates. Part of the VIP KO mice (25 %) failed to ovulate or ovulated oocytes incompetent to be fertilized (50 %). In particular, ovaries of young KO mice exhibited features of premature aging accompanied by a pro-inflammatory milieu with increased levels of IL-1ß. A unique macrophage subpopulation identified as "foamy macrophages" was found. On the other hand, aged VIP KO females did not gain body weight probably due to the sustained production of E2. Finally, the adoptive transfer of FOXP3+ cells to infertile VIP KO females resulted in their selective recruitment to the ovary. It increased FOXP3/RORγt and TGFß/IL-6 ratio improving ovarian microenvironment and pregnancy rate. The present results suggest that VIP contributes to ovarian homeostatic mechanisms required for a successful pregnancy.