Expression and cellular localization of interleukin-6 mRNA in ovariectomized rats

Abstract

In order to observe the expression and cellular localization of interleukin-6 (IL-6) mRNA in bone tissue, ovaria of the rats were excised to develop osteoporosis model. The expression of IL-6 mRNA in bone tissues was detected by using dot blot hybridization assay and the cells producing IL-6 identified and localized by using in situ hybridization respectively. The results showed that the expression of IL-6 mRNA was significantly increased in the ovariectomized rats as compared with that in normal control rats and strong IL-6 mRNA hybridization signals were detected in lining cells, osteoblasts and osteocytes. It was suggested that loss of ovarian function induced in vivo osteoblast lineage increased IL-6 mRNA expression. IL-6 might play important roles in the development of bone loss following ovariectomy.

Keywords

interleukin-6 / ovariectomy / dot blot hybridization / in situ hybridization

References

[1] KellyP J, EismanJ A. Osteoporosis: genetic effects on bone turnover and bone density. Ann Med, 1992, 25: 99-99

[2] NemethG G, HeydemanA, BolanderC. Isolation and analysis of ribonucleic acid from skeletal tissues. Anal Biochem, 1988, 24: 84-84

[3] AbeT, ChoJ W M, LeanJ M, et al.. Estrogen do not restore bone loss after ovx in the rat. J Bone Miner Res, 1993, 8: 831-831

[4] TamuraT, UdagawaN, TakahashiN, et al.. Soluble interleukin-6 receptor triggers osteoclast formation by interleukin-6. Proc Natl Acad Sci USA, 1993, 90: 11924-11924

[5] KalaD N. The ovariectomized rat model of postmenopausal bone loss. Bone Miner, 1991, 15: 175-175

[6] Van BezooijenR L, Farih-SipsH C M, PapapoulosS E, et al.. IL-la, IL-1β, IL-6, and TNF-a steady-state mRNA level analyzed by RT-PCR in bone marrow of gonadectamized mice. J Bone Miner Res, 1998, 13: 185-185

[7] HoltI, DavieM W J, MarshallM J. Osteoclasts are not the major source of interleukin-6 in mouse parietal bones. Bone, 1996, 18: 221-221

[8] LangubM C, KoszewskinN J, TurnerH V, et al.. Bone resorption and mRNA expression of IL-6 and IL-6 receptor in patients with renal osteodystrophy. Kidney Int, 1996, 50: 515-515

[9] Martin T J. Hormones in the coupling of bone resorption and formation. Osteoporosis Int, 1993, (Suppl 1):sl21

[10] ManolagasS C, BellidoT, JilkaR. New insights into the cellular, biochemical, and molecular basis of postmenopausal and senile osteoporosis: Role of IL-6 and gpl30. Int J Immun, 1995, 17: 109-109

[11] EriksenE, ColvardD S, BergN J, et al.. Evidence of estrogen receptors in normal human osteoblast-like cells. Science, 1988, 24: 84-84

[12] PottatzS, BellidoT, MocharlaH, et al.. 17β-estrodiol inhibits expression of human interleukin-6 promoter-reporter constructs by a receptor-dependent mechanism. J Clin Invest, 1994, 93: 944-944

[13] HorowitzM C. Cytokines and estrogen in bone: Antiosteiopotic effects. Science, 1993, 260: 626-626