The anti-androgen hydroxyflutamide and androgens inhibit interleukin-6 production by an androgen-responsive human osteoblastic cell line
The anti-androgen hydroxyflutamide and androgens inhibit interleukin-6 production by an androgen-responsive human osteoblastic cell line
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DOI：
10.1359/jbmr.1999.14.8.1330
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发表时间：
1999-08-01
影响因子：
6.2
通讯作者：
Khosla, S
中科院分区：
文献类型：
--
作者：
Hofbauer, LC;Ten, RM;Khosla, S
虽然雄激素明显具有显著的骨骼效应，但雄激素对骨作用的旁分泌介质目前尚不清楚。白介素6(IL-6)是一种由成骨细胞系细胞产生的促进破骨细胞生成和骨吸收的候选细胞因子。在这里，我们通过Northern分析评估了组成性以及IL-1β和肿瘤坏死因子-α(TNF-α)刺激的IL-6mRNA的表达，并通过免疫分析方法评估了人雄激素反应性成骨细胞系(hFOB/AR-6)的蛋白质分泌，该细胞含有类似于4000个雄激素受体(AR)/核。在10(-7)M时，5α-二氢睾酮(DHT)呈剂量依赖性地抑制hFOB/AR-6细胞的构成和由TNF-α/IL-1β刺激的IL-6mRNA的稳态水平70-80%。此外，睾酮还可将TNF-α/IL-1β刺激的IL-6的mRNA水平抑制57%，而肾上腺雄激素脱氢表雄酮对此无影响。值得注意的是，AR特异性拮抗剂羟基氟他胺也将IL-6mRNA水平抑制了70%。与Northern分析一致的是，5-α-二羟色胺、睾酮和羟基氟他胺处理后，IL-6蛋白的生成分别抑制了79%、62%和71%(p<；0.001)，而这些药物对IL-6可溶性受体水平没有影响。最后，我们证明了羟基氟他胺处理hFOB/AR-6细胞后，显著抑制了已知的IL-6基因转录刺激因子--核因子-kappaB的激活和与其反应元件的结合，从而为其影响成骨细胞产生IL-6提供了一个潜在的机制。这些数据与雄激素抑制成骨细胞产生IL-6可能至少部分地介导了雄激素对骨的抗吸收作用这一假说是一致的。此外，我们的研究结果还表明，在大多数组织中已知的AR拮抗剂羟基氟他胺可能作为选择性AR调节剂对成骨细胞产生IL-6起作用。
While androgens clearly have significant skeletal effects, the paracrine mediators of androgen action on bone are at present unclear. Interleukin-6 (IL-6) is a candidate cytokine that is produced by osteoblastic lineage cells and promotes osteoclastogenesis and bone resorption. Here, we assessed constitutive as well as IL-1 beta- and tumor necrosis factor-alpha (TNF-alpha)-stimulated IL-6 mRNA expression by Northern analysis and protein secretion by immunoassay in a human androgen-responsive osteoblastic cell line (hFOB/AR-6) which contains similar to 4000 androgen receptors (ARs)/nucleus. Treatment with 5 alpha-dihydrotestosterone (DHT) dose-dependently inhibited constitutive and TNF-alpha/IL-1 beta-stimulated IL-6 mRNA steady-state levels in hFOB/AR-6 cells by 70-80% at 10(-7) M. In addition, testosterone also suppressed TNF-alpha/IL-1 beta-stimulated IL-6 mRNA levels by 57%, while the adrenal androgen dehydroepiandrosterone had no effect. Of note, the specific AR antagonist, hydroxyflutamide, also inhibited IL-6 mRNA levels by 70%. Consistent with the Northern analyses, treatment with 5 alpha-DHT, testosterone, and hydroxyflutamide also inhibited IL-6 protein production by 79%, 62%, and 71%, respectively (p < 0.001), while these agents had no effect on IL-6 soluble receptor levels. Finally, we demonstrated that hydroxyflutamide treatment of hFOB/AR-6 cells markedly inhibited the activation and binding of NF-kappa B (a known stimulator of IL-6 gene transcription) to its response element, thus providing a potential mechanism for its effect on IL-6 production by osteoblasts. These data are consistent with the hypothesis that suppression of osteoblast IL-6 production by androgens may mediate, at least in part, the antiresorptive effects of androgens on bone, Moreover, our findings also indicate that hydroxyflutamide, which is a known AR antagonist in most tissues, may function as a selective AR modulator for effects on IL-6 production by osteoblasts.