Expression profiles of fetal membrane nicotinamide adenine dinucleotide phosphate oxidases (NOX) 2 and 3 differentiates spontaneous preterm birth and pPROM pathophysiologies.
BACKGROUND
Nicotinamide adenine dinucleotide phosphate oxidases (NOX 1-5) are enzymes that generate cellular reactive oxygen species (ROS) besides mitochondria and might be important ROS sources associated with pregnancy complications, particularly preterm premature rupture of membranes (pPROM), that has been related to ROS.


OBJECTIVE
To characterize NOX enzymes expression in human fetal membranes.


METHODS
Differential expression and localization of NOX isoforms in human fetal membranes collected from women with uncomplicated pregnancies at term, preterm birth (PTB) or pPROM and in vitro in normal term membranes maintained in an organ explant system stimulated with water-soluble cigarette smoke extract (wsCSE) were documented by real time PCR and immunohistochemistry.


RESULTS
Fetal membranes from term deliveries, PTB and pPROM expressed NOX 2, 3 and 4 mRNAs whereas NOX 1 and 5 were not detected. NOX 2 expression was 2.3-fold higher in PTB than pPROM (p = 0.005) whereas NOX 3 was 2.2-fold higher in pPROM compared to PTB (p = 0.04). NOX 2 and 3 expressions at term mimicked pPROM and PTB, respectively. No difference in NOX 4 expression was observed among the studied groups. NOX 2, 3 and 4 were localized to both amniotic and chorionic cells. Expression of NOX 2, 3 and 4 were not significant in wsCSE-stimulated membranes compared to untreated controls.


CONCLUSIONS
NOX enzymes are present in the fetal membranes and are differentially expressed in PTB and pPROM. Absence of any changes in NOXs expression after wsCSE stimulation suggests ROS generation in the membranes does not always correlate with NOX expression.
Division of Maternal-Fetal Medicine and Perinatal Research, Department of Obstetrics and Gynecology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA; Department of Pathology, Botucatu Medical School, UNESP - Univ. Estadual Paulista, Botucatu, Sao Paulo, Brazil.
J
J
Polettini
Department of Pathology, Botucatu Medical School, UNESP - Univ. Estadual Paulista, Botucatu, Sao Paulo, Brazil.
M G
MG
Silva
Biomedical Research Center, University Hospital Hradec Kralove, Czech Republic; Department of Obstetrics and Gynecology, Charles University in Prague, Faculty of Medicine, Hradec Kralove, Czech Republic.
M
M
Kacerovsky
Division of Maternal-Fetal Medicine and Perinatal Research, Department of Obstetrics and Gynecology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA.
T A
TA
Syed
Division of Maternal-Fetal Medicine and Perinatal Research, Department of Obstetrics and Gynecology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA.
G
G
Saade
Division of Maternal-Fetal Medicine and Perinatal Research, Department of Obstetrics and Gynecology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA. Electronic address: ra2menon@utmb.edu.
R
R
Menon
D000328:Adult; D005321:Extraembryonic Membranes / Q000201:enzymology*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000201:enzymology*; D006801:Humans; D007231:Infant, Newborn; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D008565:Membrane Proteins / Q000096:biosynthesis*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000096:biosynthesis*; D011247:Pregnancy; D047928:Premature Birth / Q000201:enzymology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012907:Smoking / Q000503:physiopathology
D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D017382:Reactive Oxygen Species; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; C431570:Nox3 protein, human
Cigarette smoking extract; Oxidase enzymes; Preterm birth; Preterm premature rupture of membranes; Reactive species of oxygen