Periovulatory and Interleukin (IL)-1—Dependent Reglation of IL-6 in the Immature Rat Ovary: A Specific IL-1 Receptor-Mediated Eicosanoid-Dependent Effect

Abstract

Interleukin (IL)-6, traditionally an IL-1—induced immune regulator, is nevertheless synthesized by a variety of tissues including the ovary. The purposes of this communication were to assess the ovarian expression of IL-6, examine its cyclic variation, and study its regulation by IL-1, a putative intermediary in the ovulatory process. Molecular probing revealed IL-6 transcripts to be most abundant in the thymus, liver, and ovary, which suggests that, in relative terms, untreated immature whole ovarian tissue is a significant site of IL-6 gene expression. Treatment of immature rats with pregnant mare serum gonadotropins resulted in a meausrable, statistically significant (P < .05) increase in ovarian IL-6 mRNA compared with untreated controls. Isolated and indeed transient increments in the relative abundance of IL-6 transcripts were noted 4 hours after exposure to hCG, a point in time 8 hours from projected follicular rupture, a pattern highly reminiscent of that previously recognized for IL-1β transcripts. Treatment of whole ovarian dispersates from immature rats with IL-1β for 48 hours resulted in a significant (P < .05) increase (11-fold) over control in IL-6 transcripts. The IL-1 effect proved dose dependent; the first significant increase was noted at the 1-ng/mL dose level. Evaluation of the time requirements revealed IL-1β to significantly (P < .05) up-reglate (4.5-fold) IL-6 transcripts as early as 24 hours into the culture period. Cotreatment with the IL-1 receptor antagonist completely reversed the IL-1 effect, which suggests mediation through a specific IL-1 receptor. Treatment with indomethacin (10 μg/mL), an established inhibitor of prostaglandin biosynthesis, resulted in a significant (P < .05) decrease (79%) in the ability of IL-1β to up-regulate IL-6 transcripts. Importantly, the addition of prostaglandin E₂ (10 μg/mL) to untreated or indomethacin-treated cells significantly (P < .05) augmented the IL-1β effect. This suggests a role for eicosanoid signaling in IL-1β action. Treatment with aminoguanidine, an established inhibitor of nitric oxide synthase, significantly (P < .05) decreased (85%) the IL-1β effect. However, the addition of S-nitroso-n-acetyl-penicilamine, an established nitrite generator, failed to reverse the aminoguanidine effect, which suggests that the inhibitor effect of aminoguanidine may be nitrite independent. Treatment with cycloheximide produced dose-dependent inhibition of the ability of IL-1 to up-regulate IL-6 transcripts; the maximal inhibitory effect was 89%. Taken together, these findings (1) reaffirm the rat ovary as a site of IL-6 expression; (2) document an in vivo increase in IL-6 transcripts before ovulation; (3) disclose a marked dependence of IL-6 on IL-1β; and (4) reveal the IL-1β effect to be dose and time dependent, receptor mediated, contingent upon de novo protein biosynthesis, and eicosanoid dependent but nitric oxide independent. These findings suggest that IL-1 action in the ovary may require the intemediacy of IL-6 in a manner like that encountered in extraovarian sites.

Keywords

Interleukin-1 interleukin-6 ovary

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References

1. Ben-Shlomo I , Adashi EY . Interleukin-1 as a mediator in the ovulatory sequence: Evidence for a meaningful role of cytokines in ovarian physiology. Curre Sci Ser 1994;1:187-192.

2. Brannstrom M , Wang L , Norman RJ . Ovulatory effect of interleukin-1 on the perfused rat ovary. Endocrinology 1993;132:399-404.

3. Takehara Y , Dharmarajan AM , Kaufman G , Wallach EE . Effects of interleukin-1β on ovulation in the in vitro perfused rabbit ovary. Endocrinology 1994;134:1788-1793.

4. Simon C , Tsafriri A , Chun S-Y , Piquette GN , Dang W , Polan ML . Interleukin-1 receptor antagonist suppresses hCG-induced ovulation in the rat. Biol Reprod 1994;51:662-667.

5. Simon C , Frances A , Piquette G , Polan ML . Immunohistochemical localization of the interleukin-1 system in the mouse ovary during follicular growth, ovulation, and luteinization. Biol Reprod 1994;50:449-457.

6. Peterson CM , Hales HA , Hatasaka HH , Mitchell MD , Rittenhouse L , Jones KP . Interleukin-1β (IL-1β) modulates prostaglandin production and the natural IL-1 receptor antagonist inhibits ovulation in the optimally stimulated rat ovarian perfusion model. Endocrinology 1993;133:2301-2306.

7. Hurwitz A , Ricciarelli E , Botero L , Rohan RM , Hernandez ER , Adashi EY . Endocrine- and autocrine-mediated regulation of rat ovarian (theca-interstitial) interleukin-1β gene expression: Gonadotropin-dependent preovulatory acquisition. Endocrinology 1992;129:3427-3429.

8. Hurwitz A , Loukides J , Ricciarelli E . The human intraovarian interleukin-1 (IL-1) system: Highly-compartmentalized and hormonally-dependent regulation of the genes encoding IL-1, its receptor, and its receptor antagonist. J Clin Invest 1992;89:1746-1754.

9. Wang L-J , Brannstrom M , Cui K-H , et al. Localisation of mRNA for interleukin-1 receptor and interleukin-1 receptor antagonist in the rat ovary. J Endocrinol 1997;152:11-17.

10.

10. Brannstrom M , Norman RJ , Seamark RF , Robertson SA . Rat ovary produces cytokines during ovulation. Biol Reprod 1994;50:88-94.

11.

11. Kokia E , Hurwitz A , Ricciarelli E , et al. Interleukin-1 stimulates ovarian prostaglandin biosynthesis: Evidence for heterologous contact-independent cell-cell interaction. Endocrinology 1992;130:3095-3097.

12.

12. Kokia E , Hurwitz A , Ben-Shlomo I , Adashi EY , Yanagisita M . Receptor mediated stimulatory effects of IL-1β on hyaluronic acid and proteoglycan biosynthesis by cultured rat ovarian cells: Role for heterologous cell-cell interactions. Endocrinology 1993;133:2391-2394.

13.

13. Hurwitz A , Dushnik M , Solomon H , et al. Cytokine-mediated regulation of rat ovarian function: Interleukin-1 stimulates the accumulation of 92-kD gelatinase. Endocrinology 1993;132:2709-2714.

14.

14. Hurwitz A , Finci-Yeheskel Z , Dushnik M , et al. Cytokine-mediated reglation of rat ovarian function: Interleukin-1 inhibits plasminogen activator activity through the stimulation of plasminogen activator inhibitor-1 (PAI-1). Mol Cell Endocrinol 1994;101:307-315.

15.

15. Ben-Shlomo I , Adashi EY , Payne DW . The morphogenic/cytotoxic and prostaglandin-stimulating activities of interleukin-1β in the rat ovary are nitric oxide-independent. J Clin Invest 1994;94:1463-1469.

16.

16. Ben-Shlomo I , Kokia E , Jackson M , Adashi EY , Payne DW . Interleukin-1β stimulates nitrate production in the rat ovary: Evidence for heterologous cell-cell interaction and for insulin-mediated regulation of the inducible isoform of nitric oxide synthase. Biol Reprod 1994;51:310-318.

17.

17. Bonello N , McKie K , Jasper M , et al. Inhibition of nitric oxide: Effects of interleukin-1β-enhanced ovulation rate, steroid hormones, and ovarian leukocyte distribution at ovulation in the rat. Biol Reprod 1996;54:436-445.

18.

18. Kol S , Ben-Shlomo I , Ruutiainen K , et al. The midcycle increase in ovarian glucose uptake is associated with enhanced expression of glucose transporter 3. Possible role for interleukin-1, a putative intermediary in the ovulatory process. J Clin Invest 1997;99:2274-2283.

19.

19. Chun SY , Eisenhauer KM , Kubo M , Hsueh AJ . Interleukin-1 beta suppresses apoptosis in rat ovarian follicles by increasing nitric oxide production. Endocrinology 1995;136:3120-3127.

20.

20. Chun SY , Eisenhauer KM , Minami S , Billig H , Perlas E , Hsueh AJ . Hormonal regulation of apoptosis in early antral follicles: Follicle-stimulating hormone as a major survival factor. Endocrinology 1996;137:1447-1456.

21.

21. Motro B , Itin A , Sachs L , Keshet E . Pattern of interleukin 6 gene expression in vivo suggests a role for this cytokine in angiogenesis. Proc Natl Acad Sci U S A 1990;87:3092-3096.

22.

22. Gorospe WC , Hughes FM Jr , Spangelo BL . Interleukin-6: effects on and production by rat granulosa cells in vitro. Endocrinology 1992;130:1750-1752.

23.

23. Gorospe WC , Spangelo BL . Interleukin-6 production by rat granulosa cells in vitro: Effects of cytokines, follicle-stimulating hormone, and cyclic 3′,5′-adenosine monophosphate. Biol Reprod 1993;48:538-543.

24.

24. Alpizar E , Spicer LJ . Effects of interleukin-6 on proliferation and follicle-stimulating hormone-induced estradiol production by bovine granulosa cells in vitro: Dependence on size of follicle [published erratum appears in Biol Reprod 1994 Apr;50(4):977]. Biol Reprod 1994;50:38-43.

25.

25. Hurwitz A , Payne DW , Packman JN , et al. Cytokine-mediated regulation of ovarian function: Interleukin-1 inhibits gonadotropin-induced androgen biosynthesis. Endocrinology 1991;129:1250-1256.

26.

26. Northemann W , Braciak TA , Hattori M , Lee F , Fey GH . Structure of the rat interleukin 6 gene and its expression in macrophage-derived cells. J Biol Chem 1989;264:16072-16082.

27.

27. Scherzer WJ , Ruutianen-Altman KSL , Putowski LT , Kol S , Adashi EY , Rohan RM . Detection and in vivo hormonal regulation of rat ovarian type I and type II interleukin-1 receptor mRNA: Increased expression during the periovulatory period. J Soc Gynecol Invest 1996;3:131-140.

28.

28. Kol S , Ben-Shlomo I , Adashi EY , Rohan RM . Simplified riboprobe purification using translucent straws as gel tubes. Gen Anal Biomol Eng 1996;12:129-132.

29.

29. Lowe WL , Roberts CT , Lasky SR , LeRoith D . Differential expression of alternative 5′ ntranslated regions in mRNA encoding rat insulin-like growth factor 1. Proc Natl Acad Sci U S A 1987;84:8946-8950.

30.

30. Kokia E , Ben-Shlomo I , Adashi EY . The ovarian action of interleukin-1 is receptor mediated: Reversal by a naturally occurring interleukin-1 receptor antagonist. Fertil Steril 1995;63:176-181.

31.

31. Sims JE , Gayle MA , Slack JL , et al. Interleukin 1 signaling occurs exclusively via the type I receptor. Proc Natl Acad Sci U S A 1993;90:6155-6159.

32.

32. Colotta F , Re F , Muzio M , et al. Interleukin-1 type II receptor: A decoy target for IL-1 that is regulated by IL-4. Science 1993;261:472-475.

33.

33. Kol S , Ben-Shlomo I , Ando M , Payne DW , Adashi EY . Interleukin-1β stimulates ovarian phosphoipase A2 (PLA2) expression and activity: Up-reglation of both secretory and cytosolic PLA2. Endocrinology 1997;138:314-321.

34.

34. Ando M , Kol S , Kokia E , et al. Rat ovarian prostaglandin endoperoxide synthase-1 and -2: Periovulatory expression of granulosa cell-based interleukin-1-dependent enzymes. Endocrinology 1998;139:2501-2508.

35.

35. Ellman C , Corbett JA , Misko TP , McDaniel M , Beckerman KP . Nitric oxide mediates interleukin-1-induced cellular cytotoxicity in the rat ovary: A potential role for nitric oxide in the ovulatory process. J Clin Invest 1993;92:3053-3056.

36.

36. Shukovski L , Tsafriri A . The involvement of nitric oxide in the ovulatory process in the rat. Endocrinology 1994;135:2287-2290.

37.

37. Hannun YA , Bell RM . Functions of sphingolipids and sphingolipid breakdown products in cellular regulation [see comments]. Science 1989;243:500-507.