Open AccessExpression of cytokine‐induced neutrophil chemoattractant suppresses tumor necrosis factor alpha expression and thereby prevents the follicles from undergoing atresia and apoptosis
Author(s) -
Tanaka Yu,
Kuwahara Akira,
Ushigoe Kenjiro,
Yano Yuya,
Taniguchi Yuka,
Yamamoto Yuri,
Matsuzaki Toshiya,
Yasui Toshiyuki,
Irahara Minoru
Publication year - 2017
Publication title -
reproductive medicine and biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.005
H-Index - 22
eISSN - 1447-0578
pISSN - 1445-5781
DOI - 10.1002/rmb2.12022
Subject(s) - tunel assay , endocrinology , medicine , tumor necrosis factor alpha , cytokine , follicular atresia , apoptosis , terminal deoxynucleotidyl transferase , ovulation , biology , andrology , follicular phase , ovarian follicle , immunohistochemistry , biochemistry , hormone
Abstract Aim Cytokine‐induced neutrophil chemoattractant ( CINC /gro) is a CXC family chemokine, similar to interleukin‐8 in rats, and is one of the factors that regulates ovulation. However, the mechanism that regulates atresia of the ovaries postovulation is not clearly defined. Methods Whether antibody‐blocking of CINC /gro can alter the number of ovulated oocytes and modulate neutrophil infiltration was investigated. The effect of the antibody on the level of inflammatory cytokine production and follicular atresia was examined. Apoptosis was measured by the terminal deoxynucleotidyl transferase‐mediated dUTP nick end labeling ( TUNEL ) method and via analysis of the messenger RNA expression of Bcl‐2 and Bcl2‐associated X (Bax). Results The anti‐ CINC /gro antibody treatment decreased the number of ovulated oocytes. The messenger RNA levels of cyclooxygenase‐2 and interleukin‐1 beta were decreased by the antibody treatment, whereas that of tumor necrosis factor (TNF) alpha was increased. The TUNEL analysis revealed a larger number of apoptotic cells in the antibody group, compared with those in the control group, as well as a significant increase in the Bax/Bcl‐2 ratio 24 hours after human chorionic gonadotropin administration. Conclusion These findings suggest that ovulation is accelerated by neutrophil infiltration into the theca layer. The CINC /gro appears to synergize with interleukin‐1 beta for ovulation. By contrast, the data suggest that CINC /gro expression suppresses TNF alpha expression and that CINC /gro expression therefore prevents the follicles from undergoing atresia and apoptosis.