Relaxin Stimulates Interleukin-6 and Interleukin-8 Secretion from the Extraplacental Chorionic Cytotrophoblast

Bryant-Greenwood, G.D.; Yamamoto, S.Y.; Sadowsky, D.W.; Gravett, M.G.; Novy, M.J.

doi:10.1016/j.placenta.2009.04.009

« Previous Next »Placenta
Volume 30, Issue 7 , Pages 599-606, July 2009

Relaxin Stimulates Interleukin-6 and Interleukin-8 Secretion from the Extraplacental Chorionic Cytotrophoblast

G.D. Bryant-Greenwood
- John A. Burns School of Medicine, 651 Ilalo Street, Honolulu, HI 96813, USA
- The Pacific Biosciences Research Center, University of Hawaii, Honolulu, Hawaii 96822, USA
- Corresponding author at: Department of Cell and Molecular Biology, University of Hawaii, 651 Ilalo Street, Bioscience Building, Honolulu, HI 96813, USA. Tel.: +1 808 692 1470; fax: +1 808 692 1966.
S.Y. Yamamoto
- The Pacific Biosciences Research Center, University of Hawaii, Honolulu, Hawaii 96822, USA
D.W. Sadowsky
- The Oregon National Primate Research Center, Oregon Health Sciences University, Beaverton, Oregon 97006, USA
M.G. Gravett
- Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle, Washington 98195, USA
M.J. Novy
- The Oregon National Primate Research Center, Oregon Health Sciences University, Beaverton, Oregon 97006, USA

Accepted 25 April 2009. published online 21 May 2009.

Abstract

In the absence of infection, decidual relaxin (RLN) expression is increased in patients with preterm premature rupture of the membranes (PPROM) resulting in preterm birth, but it is not known whether inflammation stimulates RLN expression or vice versa. This study examined the effect of lipopolysaccharide (LPS) on the expression of RLN mRNA and secreted protein and whether RLN treatment influences secretion of proinflammatory cytokines from the fetal membranes. Explants of human fetal membranes in vitro and rhesus monkey fetal membranes in vivo were treated with LPS, which increased expression of IL-6 but had no effect on RLN. RLN treatment stimulated IL-6 and IL-8 secretion from choriodecidual explants in a subset of patients, as well as from isolated chorionic cytotrophoblast cells but not decidual cells. In vivo results obtained in rhesus monkeys after intra-amniotic infusion of RLN demonstrated increased IL-6 and IL-8 concentrations in amniotic fluid. Our results indicate that increased decidual RLN expression is independent of LPS but may induce a local sterile inflammatory process which potentially contributes to extracellular matrix degradation and weakening of the fetal membranes.

Keywords: Relaxin, Proinflammatory cytokines, Preterm premature rupture of membranes