Effect of hypoxia on endothelial nitric oxide synthase, NO production, intracellular survival signaling (p-ERK1/2 and p-AKT) and apoptosis in human term trophoblast.
OBJECTIVE
Hypoxia is commonly associated with complicated pregnancies such as intrauterine growth restriction. We evaluated the effects of hypoxia on phospho (p)-eNOS, p-ERK, p-AKT and apoptosis in human trophoblast.


METHODS
Isolated trophoblast were cultured in 21% oxygen or 2% oxygen for 24, 48 and 72 hr. p-eNOS, p-ERK and p-AKT protein were assessed by Western blot and apoptosis by TUNEL assay. NOx was determined in the culture media.


RESULTS
Compared to controls, hypoxia-exposed CT showed the following: (1) decreased eNOS at 48 and 72 hr, (2) increased p-eNOS at 48 hr, (3) no differences in total NOx production, (4) increased p-ERK at 24, 48 and 72 hr, (5) increased p-AKT at 24 hr (P < 0.05) and (6) increased apoptosis at 48 hr.


CONCLUSIONS
Hypoxia increases activation of p-ERK and induces apoptosis of cultured trophoblast. Hypoxia decreases overall total eNOS but increases p-eNOS, which may allow for NO production to be maintained in trophoblast cells.
Park
Mi-Hye
MH
Division of Perinatal medicine, Department of Obstetrics, University of Colorado at Denver Health Sciences Center, USA.
Galan
Henry L
HL
Arroyo
Juan A
JA
D017209:Apoptosis; D015153:Blotting, Western; D015687:Cell Hypoxia; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D020287:In Situ Nick-End Labeling; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010766:Phosphorylation; D011247:Pregnancy; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014327:Trophoblasts / Q000502:physiology*
D012333:RNA, Messenger; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D051057:Proto-Oncogene Proteins c-akt; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3