Interleukin-1 (IL-1) system gene expression in granulosa cells: kinetics during terminal preovulatory follicle maturation in the mare.
BACKGROUND
A growing body of evidences suggests that the ovary is a site of inflammatory reactions, and thus, ovarian cells could represent sources and targets of the interleukin-1 (IL-1) system. The purpose of this study was to examine the IL-1 system gene expressions in equine granulosa cells, and to study the IL-1beta content in follicular fluid during the follicle maturation. For this purpose, granulosa cells and follicular fluids were collected from the largest follicle at the early dominance stage (diameter 24 +/- 3 mm) or during the preovulatory maturation phase, at T0 h, T6 h, T12 h, T24 h and T34 h after induction of ovulation. Cells were analysed by RT-PCR and follicular fluids were studied by gel electrophoresis and immunoblotting.


RESULTS
We demonstrated that interleukin-1beta (IL-1beta), interleukin-1 receptor 2 (IL-1R2) and interleukin-1 receptor antagonist (IL-1RA) genes are expressed in equine granulosa cells. We observed that the IL-1beta and IL-1RA mRNA content changed in granulosa cells during the terminal follicular maturation whereas IL-1R2 mRNA did not vary. In follicular fluid, IL-1beta content fluctuated few hours after induction of ovulation.


CONCLUSIONS
The expression of IL-1beta gene in granulosa cells and the follicular fluid IL-1beta content seem to be regulated by gonadotropins suggesting that IL-1beta could be an intermediate paracrine factor involved in ovulation.
Martoriati
Alain
A
Reproduction Equine, Physiologie de la Reproduction et des Comportements, INRA UMR6073, 37380 Nouzilly, France. martoria@tours.inra.fr
Gérard
Nadine
N
D000818:Animals; D015153:Blotting, Western; D001826:Body Fluids / Q000737:chemistry; D005260:Female; D005786:Gene Expression Regulation; D006065:Gonadotropins, Pituitary / Q000502:physiology; D006107:Granulosa Cells / Q000378:metabolism*; D006736:Horses / Q000235:genetics / Q000502:physiology*; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000235:genetics; D006080:Ovarian Follicle / Q000737:chemistry; D010060:Ovulation / Q000502:physiology*; D017472:Receptors, Interleukin-1 / Q000096:biosynthesis* / Q000235:genetics; D053574:Receptors, Interleukin-1 Type II; D020133:Reverse Transcriptase Polymerase Chain Reaction
D006065:Gonadotropins, Pituitary; D007375:Interleukin-1; D017472:Receptors, Interleukin-1; D053574:Receptors, Interleukin-1 Type II