Morioka M, Shimodaira K, Kuwano Y, Fujikawa H, Saito H, Yanaihara T
Department of Obstetrics and Gynecology, Showa University School of Medicine, 1-5-8, Hatanodai, Shinagawa-ku, Tokyo, 142-8666, Japan.
Biochem Biophys Res Commun. 2000 Feb 5;268(1):60-4. doi: 10.1006/bbrc.1999.2063.
Osteoblast cells have a capacity to produce estrogen from androgen. It is known that inflammatory cytokines in bone increase during estrogen deficiency. In the present study, the effect of interleukin-1beta (IL-1beta) on aromatase (Arom) activity in human osteoblast-like cells (HOS) was investigated. We also investigated the effect of IL-1beta and estradiol (E2) on cell proliferation in HOS. [(3)H] water method was employed to measure Arom activity. Expression of Arom mRNA was determined by the reverse-transcription polymerase chain reaction (RT-PCR) method. The PCR products were confirmed by Southern blot analysis. Cell proliferation was measured by an ELISA-bromo deoxyuridine (BrdU) kit. Addition of IL-1beta increased Arom activity in a dose-dependent manner and addition of IL-1beta (10 ng/ml) resulted in 40% greater activity than control. Addition of 500 ng/ml of human recombinant IL-1 receptor antagonist neutralized the increased Arom activity to control level. Stimulation of Arom mRNA expression by IL-1beta was also found. IL-1beta and E2 stimulate osteoblastic cell proliferation significantly. These findings suggest for the first time that IL-1beta stimulates Arom activity through the IL-1 receptor and also cell proliferation in osteoblast-like cells. It is also demonstrated that this stimulatory effect may be through the IL-1 receptor. Cell proliferation stimulated by IL-1beta was reduced by the addition of the Arom inhibitor fadrozole-HCL (CGS-16949A). These results imply that IL-1beta has a stimulatory effect on estrogen formation and sequentially cell proliferation in bone, and this mechanism may play an important role in osteoblastic function especially in postmenopausal women.
成骨细胞具有从雄激素生成雌激素的能力。已知雌激素缺乏时骨中的炎性细胞因子会增加。在本研究中，研究了白细胞介素-1β（IL-1β）对人成骨样细胞（HOS）中芳香化酶（Arom）活性的影响。我们还研究了IL-1β和雌二醇（E2）对HOS细胞增殖的影响。采用[³H]水法测量Arom活性。通过逆转录聚合酶链反应（RT-PCR）法测定Arom mRNA的表达。PCR产物通过Southern印迹分析进行确认。通过ELISA-溴脱氧尿苷（BrdU）试剂盒测量细胞增殖。添加IL-1β以剂量依赖性方式增加Arom活性，添加IL-1β（10 ng/ml）导致活性比对照高40%。添加500 ng/ml的人重组IL-1受体拮抗剂可将增加的Arom活性中和至对照水平。还发现IL-1β刺激Arom mRNA表达。IL-1β和E2显著刺激成骨细胞增殖。这些发现首次表明IL-1β通过IL-1受体刺激Arom活性以及成骨样细胞中的细胞增殖。还证明这种刺激作用可能是通过IL-1受体。添加芳香化酶抑制剂法倔唑盐酸盐（CGS-16949A）可降低IL-1β刺激的细胞增殖。这些结果表明IL-1β对骨中雌激素形成以及随后的细胞增殖具有刺激作用，并且这种机制可能在成骨细胞功能中尤其是在绝经后妇女中起重要作用。
