Yang R S, Fu W M, Wang S M, Lu K S, Liu T K, Lin-Shiau S Y
Department of Orthopaedics, College of Medicine, National Taiwan University, Taipei.
Bone. 1998 Jun;22(6):629-36. doi: 10.1016/s8756-3282(98)00055-6.
Prostaglandin E (PGE)-induced morphological changes of osteoblasts and its possible mechanisms were investigated in cultured calvaria and isolated osteoblasts from long bone fragments of neonatal rats. The control osteoblasts, either on the calvaria or isolated from the long bone fragments, were flat, polygonal in shape, and arranged in a monolayer under scanning electron microscopy (SEM) or phase contrast microscopy. Treatment with 1 mumol/L of prostaglandin E2 (PGE2, 2 h) caused these bone cells to contract a soma, whereas 10 and 100 mumol/L PGE2 (2 h) caused 18%-30% of the bone cells to elongate and expose the undersurface. Incubation of the cultured osteoblasts with PGE2 at different time periods showed a bell-shaped pattern with the optimal response at 2 h of incubation. A similar reaction can be induced by treatment with prostaglandin E1 (PGE1) or dibutyryl cyclic adenosine monophosphate (DBcAMP) in combination with 3-isobutyl-1-methylxanthine (IBMX). Furthermore, we assessed the percentage of responsive isolated bone cells to investigate interactions with other agents. The morphological changes induced by PGEs were inhibited by H-8, a protein kinase inhibitor. On the other hand, elevated intracellular calcium enhanced the PGE-induced morphological changes. Fluorescence labeling showed that PGEs caused the breakdown of the actin microfilaments, but spared the microtubules and vimentin filaments in the isolated osteoblast-like cells. These results suggest that the morphological changes of osteoblasts induced by PGEs may be related to the intracellular cAMP and calcium levels.
在新生大鼠颅骨培养物和从长骨碎片分离的成骨细胞中，研究了前列腺素E（PGE）诱导的成骨细胞形态变化及其可能机制。无论是颅骨上的对照成骨细胞还是从长骨碎片分离的对照成骨细胞，在扫描电子显微镜（SEM）或相差显微镜下均呈扁平、多边形，单层排列。用1μmol/L前列腺素E2（PGE2，2小时）处理导致这些骨细胞收缩胞体，而10和100μmol/L PGE2（2小时）导致18%-30%的骨细胞伸长并暴露下表面。在不同时间段用PGE2孵育培养的成骨细胞显示出钟形模式，在孵育2小时时反应最佳。用前列腺素E1（PGE1）或二丁酰环磷酸腺苷（DBcAMP）联合3-异丁基-1-甲基黄嘌呤（IBMX）处理可诱导类似反应。此外，我们评估了反应性分离骨细胞的百分比，以研究与其他试剂的相互作用。PGEs诱导的形态变化被蛋白激酶抑制剂H-8抑制。另一方面，细胞内钙升高增强了PGE诱导的形态变化。荧光标记显示，PGEs导致分离的成骨样细胞中肌动蛋白微丝断裂，但微管和波形蛋白丝未受影响。这些结果表明，PGEs诱导的成骨细胞形态变化可能与细胞内cAMP和钙水平有关。
