Mitochondrial manganese superoxide dismutase mRNA expression in human chorioamniotic membranes and its association with labor, inflammation, and infection.
OBJECTIVE
Human parturition is characterized by the activation of genes involved in acute inflammatory responses in the fetal membranes. Manganese superoxide dismutase (Mn SOD) is a mitochondrial enzyme that scavenges reactive oxygen species (ROS). Mn SOD is up-regulated in sites of inflammation and has an important role in the down-regulation of acute inflammatory processes. Therefore, the aim of this study was to determine the differences in Mn SOD mRNA expression in the fetal membranes in patients with term and preterm labor (PTL) as well as in acute chorioamnionitis.


METHODS
Fetal membranes were obtained from patients in the following groups: (1) term not in labor (n = 29); (2) term in labor (n = 29); (3) spontaneous PTL with intact mebranes (n = 16); (4) PTL with histological chorioamnionitis (n = 12); (5) preterm prelabor rupture of the membranes (PPROM; n = 17); and (6) PPROM with histological chorioamnionitis (n = 21). Mn SOD mRNA expression in the membranes was determined by quantitative real-time reverse transcription-polymerase chain reaction.


RESULTS
(1) Mn SOD mRNA expression was higher in the fetal membranes of patients at term in labor than those not in labor (2.4-fold; p = 0.02); (2) the amount of Mn SOD mRNA in the fetal membranes was higher in PTL than in term labor or in PPROM (7.2-fold, p = 0.03; 3.2-fold, p = 0.03, respectively); (3) Mn SOD mRNA expression was higher when histological chorioamnionitis was present both among patients with PPROM (3.8-fold, p = 0.02) and with PTL (5.4-fold, p = 0.02) than in patients with these conditions without histological chorioamnionitis; (4) expression of Mn SOD mRNA was higher in PTL with chorioamnionitis than in PPROM with chorioamnionitis (4.3-fold, p = 0.03).


CONCLUSIONS
The increase in Mn SOD mRNA expression by fetal membranes in term labor and in histological chorioamnionitis in PTL and PPROM suggests that the fetus deploys anti-oxidant mechanisms to constrain the inflammatory processes in the chorioamniotic membranes.
Than
Nandor Gabor
NG
Perinatology Research Branch, NICHD, NIH, DHHS, Detroit, Michigan 48201, USA.
Romero
Roberto
R
Tarca
Adi L
AL
Draghici
Sorin
S
Erez
Offer
O
Chaiworapongsa
Tinnakorn
T
Kim
Yeon Mee
YM
Kim
Sun Kwon
SK
Vaisbuch
Edi
E
Tromp
Gerard
G
D000293:Adolescent; D000328:Adult; D002821:Chorioamnionitis / Q000201:enzymology*; D003430:Cross-Sectional Studies; D005321:Extraembryonic Membranes / Q000201:enzymology*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000201:enzymology; D006801:Humans; D007752:Obstetric Labor, Premature / Q000201:enzymology*; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*; D047929:Term Birth
D012333:RNA, Messenger; D013482:Superoxide Dismutase