Yamaguchi Masayoshi, Misawa Hiroyuki, Uchiyama Satoshi, Morooka Yoshiko, Tsurusaki Yoshinori
Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Japan.
Int J Mol Med. 2002 Oct;10(4):377-83.
The role of endogenous regucalcin in the regulation of bone metabolism was investigated by using regucalcin transgenic (TG) rats. The expression of regucalcin mRNA in the femoral-diaphyseal and -metaphyseal tissues of normal (wild-type) rats was shown by using reverse transcription-polymerase chain reaction (RT-PCR) with a specific primer of regucalcin cDNA. Regucalcin protein was detected in the femoral-diaphyseal and -metaphyseal tissues of normal (wild-type) rats using Western analysis. Regucalcin levels were significantly increased in the femoral-metaphyseal tissues of regucalcin TG male rats and in the diaphyseal and metaphyseal tissues of the TG female rats. The morphologic change in the femoral-diaphyseal and -metaphyseal tissues of regucalcin TG rats was demonstrated by using a peripheral quantitative computed tomography (pQCT); morphologic change was great in the femoral tissues of female rats as compared with that of male rats. Mineral content, mineral density and polar strength strain index in the femoral-diaphyseal and -metaphyseal tissues were markedly reduced in regucalcin TG female rats. A significant decrease in cortical thickness was seen in the femoral diaphysis of regucalcin TG female rats. Calcium content in the femoral-diaphyseal and -metaphyseal tissues was significantly decreased in regucalcin TG male and female rats; a remarkable decrease was seen in female rats. Femoral-metaphyseal alkaline phosphatase activity was significantly lowered in regucalcin TG female rats. The enzyme activity was not significantly changed in the femoral-diaphyseal tissues of the TG female rats. In the diaphyseal tissue of male rats, the enzyme activity was significantly decreased in the TG rats. A significant decrease in deoxyribonucleic acid (DNA) content was seen in the metaphyseal tissue of regucalcin TG male rats and in the diaphyseal and metaphyseal tissues of the TG female rats. This study demonstrates that bone loss is induced in the femoral tissue of regucalcin transgenic rats, and that a remarkable decrease in bone morphologic index and biochemical component was seen in the female rats. Regucalcin may be involved in the regulation of bone metabolism.
通过使用regucalcin转基因（TG）大鼠研究内源性regucalcin在骨代谢调节中的作用。使用regucalcin cDNA特异性引物通过逆转录 - 聚合酶链反应（RT-PCR）显示正常（野生型）大鼠股骨干和干骺端组织中regucalcin mRNA的表达。使用蛋白质免疫印迹法在正常（野生型）大鼠的股骨干和干骺端组织中检测到regucalcin蛋白。Regucalcin TG雄性大鼠的股骨远端干骺端组织以及TG雌性大鼠的骨干和干骺端组织中Regucalcin水平显著升高。使用外周定量计算机断层扫描（pQCT）显示regucalcin TG大鼠股骨干和干骺端组织的形态学变化；与雄性大鼠相比，雌性大鼠股骨组织的形态学变化更大。Regucalcin TG雌性大鼠股骨干和干骺端组织中的矿物质含量、矿物质密度和极性强度应变指数显著降低。Regucalcin TG雌性大鼠股骨干皮质厚度显著降低。Regucalcin TG雄性和雌性大鼠股骨干和干骺端组织中的钙含量显著降低；雌性大鼠中钙含量显著下降。Regucalcin TG雌性大鼠股骨远端干骺端碱性磷酸酶活性显著降低。TG雌性大鼠股骨干组织中酶活性无显著变化。在雄性大鼠的骨干组织中，TG大鼠的酶活性显著降低。Regucalcin TG雄性大鼠的干骺端组织以及TG雌性大鼠的骨干和干骺端组织中脱氧核糖核酸（DNA）含量显著降低。本研究表明，regucalcin转基因大鼠的股骨组织中出现骨质流失，并且雌性大鼠的骨形态学指标和生化成分显著下降。Regucalcin可能参与骨代谢的调节。
