Intracellular localization and expression of importin 8 during osteoblast differentiation / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To observe the variations of intracellular localization and expression of importin 8 (IPO8) during osteoblast differentiation.</p><p><b>METHODS</b>Alizarin red staining, immunocytochemistry and real-time PCR were employed to examine the changes in the intracellular localization and expression of IPO8 mRNA during induced osteogenic differentiation of human osteoblast-like SaOS-2 cells.</p><p><b>RESULTS</b>Numerous red mineralized nodules were observed on day 10 in the induced cells with alizarin red staining. Immunocytochemical staining showed that IPO8 immunoreactivity was the strongest in the perinuclear cytoplasm of the cells. On day 3 of osteoblast differentiation, IPO8 immunoreactivity in the cell nuclei became stronger. On day 7, IPO8 was located mainly in the nuclei, and on day 10 the cells were osteocyte-like and IPO8 was distributed in the cytoplasm. Real-time PCR showed a significantly increased expression of OPN mRNA during osteoblast differentiation, and the expression level of IPO8 mRNA was the highest on day 3 and declined on days 7 and 10.</p><p><b>CONCLUSION</b>The intracellular localization and expression level of IPO8 undergo significant changes during osteogenesis, indicating its role in regulating osteoblast differentiation.</p>