Testicular interleukin 1b (IL1b): Its role on the regulation of cyclooxygenase 2 (COX2) expression and possible relevance to male fertility

MATZKIN ME; GONZALEZ-CALVAR SI, MAYERHOFER A, CALANDRA RS, FRUNGIERI MB.

Buenos Aires, Argentina

Jornada; Jornada de la Sociedad Argentina de Biología, SAB; 2006

Sociedad Argentina de Biología

We have described: 1) an increased number of macrophages (MAC) containing IL1b and induction of interstitial COX2 expression (key enzyme in the biosynthesis of prostaglandins, PGs) in testicular biopsies from infertile men, 2) COX2 expression in testes of adult Syrian hamsters exposed to a long-day photoperiod (LD, 14h light: 10h dark) but not in those exposed to a short-day photoperiod (SD, 6h light: 18h dark), 3) PGJ2 induction of human testicular fibrosis, 4) PGF2a inhibition of hamster testicular testosterone production (Frungieri et al, Fertil Steril 78, 2002; PNAS USA 99, 2002; Endocrinology 147, 2006). The aims of this study were to investigate the testicular expression of IL1b, its receptors (RI and RII), the antagonist receptor (Ra), as well as the effect of IL1b on COX2 expression. Expression of IL1b and RI was detected by RT-PCR and immunohistochemistry in COX2-positive Leydig cells isolated by: 1) laser microdissection from human biopsies of patients with germ arrest and Sertoli cell only syndromes, 2) Percoll density gradient from LD-hamsters. In addition, IL1b significantly increased COX2 expression (RT-PCR, ´fold change´ units, basal: 1±0.2; IL1b 50 ng/ml: 8.1±0.7, P<0.05) in LD-hamster Leydig cells. COX2-negative Leydig cells from SD-hamsters did not expressed IL1b. Thus, IL1b induces testicular COX2 expression in hamsters. Normal human testes with few IL1b-positive MAC do not express COX2, but pathological human testes with an increased number of MAC show expression of IL1b, RI and COX2 in Leydig cells suggesting a key role of IL1b on testicular COX2 expression and PGs production in male infertility.