Differential in vitro actions of nitric oxide on human endometrial cell survival.
OBJECTIVE
To investigate the presence of caspase-3 and Bcl-2 concentration in human endometrial tissue throughout the menstrual cycle, and study the effect of nitric oxide (NO) on cell proliferation and apoptosis during culture.


METHODS
Expression of caspase-3 and Bcl-2 concentration in endometrial explants, and examination of L-arginine (L-Arg) effect on epithelial and stromal cell proliferation and apoptosis in vitro.


METHODS
Prospective study.Twenty-seven eumenorrheic women (37 +/- 1.2 years).


METHODS
Endometrial samples were obtained with Pipelle suction curette from the corpus of the uterus.


METHODS
Apoptosis (annexin V-FITC binding), Bcl-2 concentration (ELISA), caspase-3 (immunohistochemistry), cell proliferation (spectrophotometric assay), and gene expression (RT-PCR).


RESULTS
Caspase-3 was detected by immunoassay in epithelial tissue throughout the menstrual cycle and in stroma during secretory phase. The Bcl-2 concentration was similar in endometrial homogenates obtained throughout the menstrual cycle, but L-Arg decreased Bcl-2 only in endometrium from the proliferative phase. In epithelial cells, NO increased apoptosis by 2.1 +/- 0.2-fold, augmented mRNA expression of Bax, and reduced expression of Bcl-2 compared with basal cultures. In stromal cells, NO increased cell proliferation in a dose-dependent manner, an effect that was blocked by a NO synthase inhibitor.


CONCLUSIONS
These data indicate that NO has a differential regulatory function on endometrial cell survival, as indicated by the results on stromal cell proliferation and epithelial cell apoptosis during culture, which suggests paracrine interactions between both cell types.
Johnson
M Cecilia
MC
Institute of Maternal and Child Research, School of Medicine, University of Chile, Santiago, Chile. cjohnson@machi.med.uchile.cl
Maliqueo
Manuel
M
Boric
M Angélica
MA
Villavicencio
Alejandra
A
Vantman
David
D
Vega
Margarita
M
D000328:Adult; D017304:Annexin A5 / Q000032:analysis / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004717:Endometrium / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008597:Menstrual Cycle / Q000502:physiology*; D009569:Nitric Oxide / Q000494:pharmacology / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D051028:bcl-2-Associated X Protein; D019323:omega-N-Methylarginine / Q000494:pharmacology
D017304:Annexin A5; C494826:BAX protein, human; D004791:Enzyme Inhibitors; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases