Omori Katsunori, Wada Shigehito, Maruyama Yusuke, Hattori Atsuhiko, Kitamura Kei-Ichiro, Sato Yusuke, Nara Masayuki, Funahashi Hisayuki, Yachiguchi Koji, Hayakawa Kazuichi, Endo Masato, Kusakari Rei, Yano Sachiko, Srivastav Ajai K, Kusui Takashi, Ejiri Sadakazu, Chen Wenxi, Tabuchi Yoshiaki, Furusawa Yukihiro, Kondo Takashi, Sasayama Yuichi, Nishiuchi Takumi, Nakano Masaki, Sakamoto Tatsuya, Suzuki Nobuo
Faculty of Economics, Asia University, Musashino, Tokyo 180-8629, Japan.
Zoolog Sci. 2012 Aug;29(8):499-504. doi: 10.2108/zsj.29.499.
Using our original in vitro assay system with goldfish scales, we examined the direct effect of prostaglandin E₂ (PGE₂) on osteoclasts and osteoblasts in teleosts. In this assay system, we measured the activity of alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) as respective indicators of each activity in osteoblasts and osteoclasts. ALP activity in scales significantly increased following treatment at high concentration of PGE₂(10⁻⁷ and 10⁻⁶ M) over 6 hrs of incubation. At 18 hrs of incubation, ALP activity also significantly increased in the PGE₂ (10⁻⁹ to 10⁻⁶ M)-treated scale. In the case of osteoclasts, TRAP activity tended to increase at 6 hrs of incubation, and then significantly increased at 18 hrs of incubation by PGE₂ (10(-7) to 10⁻⁶ M) treatment. At 18 hrs of incubation, the mRNA expression of osteoclastic markers (TRAP and cathepsin K) and receptor activator of the NF-κB ligand (RANKL), an activating factor of osteoclasts expressed in osteoblasts, increased in PGE₂ treated-scales. Thus, PGE₂ acts on osteoblasts, and then increases the osteoclastic activity in the scales of goldfish as it does in the bone of mammals. In an in vivo experiment, plasma calcium levels and scale TRAP and ALP activities in the PGE₂-injencted goldfish increased significantly. We conclude that, in teleosts, PGE₂ activates both osteoblasts and osteoclasts and participates in calcium metabolism.
利用我们最初建立的金鱼鳞片体外检测系统，我们研究了前列腺素E₂（PGE₂）对硬骨鱼破骨细胞和成骨细胞的直接作用。在该检测系统中，我们分别测量了碱性磷酸酶（ALP）和抗酒石酸酸性磷酸酶（TRAP）的活性，作为成骨细胞和破骨细胞各自活性的指标。在高浓度PGE₂（10⁻⁷和10⁻⁶ M）处理6小时后，鳞片中的ALP活性显著增加。在孵育18小时时，PGE₂（10⁻⁹至10⁻⁶ M）处理的鳞片中ALP活性也显著增加。对于破骨细胞，在孵育6小时时TRAP活性有增加的趋势，然后在孵育18小时时，经PGE₂（10⁻⁷至10⁻⁶ M）处理后显著增加。在孵育18小时时，PGE₂处理的鳞片中破骨细胞标志物（TRAP和组织蛋白酶K）的mRNA表达以及在成骨细胞中表达的破骨细胞激活因子核因子κB受体活化因子配体（RANKL）增加。因此，PGE₂作用于成骨细胞，然后像在哺乳动物骨骼中一样增加金鱼鳞片中的破骨细胞活性。在体内实验中，注射PGE₂的金鱼血浆钙水平以及鳞片TRAP和ALP活性显著增加。我们得出结论，在硬骨鱼中，PGE₂激活成骨细胞和破骨细胞并参与钙代谢。
