A combination of interleukin-6 and its soluble receptor impairs sperm motility: implications in infertility associated with endometriosis.
BACKGROUND
We previously reported that the level of interleukin (IL)-6 is increased in the peritoneal fluid of women with endometriosis. This study was undertaken to assess the effects of IL-6 and soluble IL-6 receptor (sIL-6R) on in vitro sperm motility.


METHODS
Sperm (n = 20) were cultured with IL-6 or sIL-6R, or with a combination of both. After 24 h cultures, sperm motility was evaluated using a computer-assisted semen analysis system. Gene and protein expressions of IL-6, IL-6 receptor (IL-6R), and glycoprotein 130 (gp130) were examined in sperm by RT-PCR analysis and western blot analysis.


RESULTS
Addition of IL-6 or sIL-6R individually to the culture media had no affect on sperm motion. However, adding a combination of IL-6 and sIL-6R dose-dependently reduced the percentage of motile and rapidly moving sperm. Adding anti-IL-6R antibody abolished these adverse effects. Sperm expressed the gp130 gene and protein, but not IL-6 or IL-6R.


CONCLUSIONS
A combination of IL-6 and sIL-6R may be associated with gp130 expressed in the sperm and reduce sperm motility. IL-6 and sIL-6R may contribute to the pathogenesis of endometriosis-associated infertility.
Yoshida
Souichi
S
Department of Obstetrics and Gynecology, Tottori University School of Medicine, Yonago 683-8504, Japan. souichi@grape.med.tottri-u.ac.jp
Harada
Tasuku
T
Iwabe
Tomio
T
Taniguchi
Fuminori
F
Mitsunari
Masahiro
M
Yamauchi
Nobuhiro
N
Deura
Imari
I
Horie
Sayako
S
Terakawa
Naoki
N
D000906:Antibodies / Q000494:pharmacology; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D001202:Ascitic Fluid / Q000378:metabolism; D002478:Cells, Cultured; D050822:Cytokine Receptor gp130; D004305:Dose-Response Relationship, Drug; D004715:Endometriosis / Q000378:metabolism / Q000503:physiopathology*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007247:Infertility, Female / Q000378:metabolism / Q000503:physiopathology*; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D019947:Receptors, Interleukin-6 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012995:Solubility; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
D000906:Antibodies; D015703:Antigens, CD; C494199:IL6ST protein, human; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D019947:Receptors, Interleukin-6; D050822:Cytokine Receptor gp130