Garcia-So J, Zhang X, Yang X, Rubinstein MR, Mao Y, Kitajewski J, Liu K, Han YW (2019) JCI Insight. 2019 Feb;4(3). pii: 125436. doi: 10.1172/jci.insight.125436. [Epub ahead of print]
Fusobacterium nucleatum is an oral anaerobe prevalent in intrauterine infection associated with a wide spectrum of adverse pregnancy outcomes. We demonstrate here that F. nucleatum triggers placentalinflammation through maternal, rather than paternal, TLR4-mediated signaling.
Elimination of TLR4 from maternalendothelialcells alleviated placentalinflammation and reduced fetal and neonatal death, while elimination of TLR4 in the hematopoietic cells had no effect. The placental inflammatory response followed a spatiotemporal pattern, with NF-κB activation observed first in the maternalendothelialcells and then in the decidual cells surrounding the endothelium, followed by induction of inflammatory cytokines and chemokines. Supplementation of pregnant mice with fish oil as a source of omega3fattyacids suppressed placentalinflammation, reduced F. nucleatum proliferation in the placenta, and increased fetal and neonatal survival. In vitro analysis illustrates that omega-3fattyacids inhibit bacterial-induced inflammatory responses from human umbilical cord endothelialcells.
Our study therefore reveals a mechanism by which microbial infections affect pregnancy and identifies a prophylactic therapy to protect against intrauterine infections.