Upregulation of interleukin-8 by hypoxia in human ovaries.
OBJECTIVE
To evaluate the effect of hypoxia on interleukin (IL)-8 expression in human ovarian follicles.


METHODS
Follicular fluid (FF) from each follicle was separately collected from women undergoing in vitro fertilization and embryo transfer. Concentrations of oxygen, progesterone, estradiol, IL-1alpha/beta, IL-8, and tumor necrosis factor (TNF)-alpha in FF were measured. Isolated granulosa-lutein cells (GLC) from obtained FF were cultured under normoxic or hypoxic conditions, and concentrations of IL-8 in culture media were measured.


RESULTS
Simple regression analysis demonstrated a significant negative correlation between the concentrations of IL-8 and oxygen in FF (r = 0.50, P < 0.0001). However, none of the concentrations of progesterone, estradiol, IL-1beta, and TNF-alpha in FF showed a significant correlation with IL-8 concentrations. Hypoxia stimulated the secretion of IL-8 by cultured GLC over twofolds compared with a normoxic control (P < 0.05).


CONCLUSIONS
These findings suggest that IL-8, like other angiogenic factors, is upregulated under hypoxic condition, which argues that hypoxia in the ovarian follicles comes into play in ovarian functions by inducing a range of proangiogenic and chemoattractive substances.
Yoshino
Osamu
O
Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, Japan.
Osuga
Yutaka
Y
Koga
Kaori
K
Hirota
Yasushi
Y
Yano
Tetsu
T
Tsutsumi
Osamu
O
Fujimoto
Akihisa
A
Kugu
Koji
K
Momoeda
Mikio
M
Fujiwara
Toshihiro
T
Taketani
Yuji
Y
D000328:Adult; D004958:Estradiol / Q000378:metabolism; D005260:Female; D015571:Follicular Fluid / Q000276:immunology / Q000378:metabolism; D006801:Humans; D000860:Hypoxia / Q000276:immunology* / Q000378:metabolism; D066298:In Vitro Techniques; D016209:Interleukin-8 / Q000378:metabolism*; D010053:Ovary / Q000276:immunology* / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; D011374:Progesterone; D004958:Estradiol