Effects of microgravity on osteoblast growth activation
Effects of microgravity on osteoblast growth activation
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DOI：
10.1006/excr.1996.0116
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发表时间：
1996-04-10
影响因子：
3.7
通讯作者：
Lewis, ML
中科院分区：
文献类型：
--
作者：
HughesFulford, M;Lewis, ML
太空飞行是一种环境条件，宇航员在长期任务中可能会失去高达19%的承重骨。我们使用MC 3 T3-E1成骨细胞来研究微重力（10（-6）至10（-9）g）下的骨细胞生长。在STS-56航天飞机上，将成骨细胞在静止状态下与0.5%胎牛血清（FCS）培养基一起发射，并通过在微重力暴露期间添加含有10%FCS的新鲜培养基来启动生长激活。血清激活后4天，细胞在恢复正常地球重力之前被固定。地面对照与飞行样品在相同的设备中平行处理。在着陆时，细胞数量，细胞骨架，葡萄糖的利用，和前列腺素的合成在飞行（n = 4）和地面控制（n = 4）进行了检查。在微重力下，流动的成骨细胞生长缓慢，总细胞数显著减少（每个显微镜视野55 +/- 6 vs 141 +/- 8个细胞）。飞行成骨细胞的细胞骨架中应力纤维数量减少，形态异常。地面对照的细胞核大而圆，DNA核小体有点状Hoechst染色。飞行核比对照组小30%（P < 0.0001），呈长方形，点状区较少。由于细胞数量减少，在微重力下活化的细胞使用的葡萄糖明显少于地面对照组（80.2 +/- 0.7 vs 50.3 +/- 3.7 mg葡萄糖/dl），与对照组相比，前列腺素E（2）（PGE（2））合成减少（57.3 +/- 17 vs 138.3 +/- 41 pmol/ml）。细胞活力是正常的，因为在每个细胞的基础上，葡萄糖的使用和前列腺素的合成是可比的飞行和地面样品。总之，这些数据表明，微重力下的生长激活导致生长减少，导致葡萄糖利用减少和前列腺素合成减少，成骨细胞中肌动蛋白细胞骨架显著改变。(C)出版社：Academic Press，Inc.
Space flight is an environmental condition where astronauts can lose up to 19% of weight-bearing bone during long duration missions, We used the MC3T3-E1 osteoblast to investigate bone cell growth in microgravity (10(-6) to 10(-9) g). Osteoblasts were launched on the STS-56 shuttle flight in a quiescent state with 0.5% fetal calf serum (FCS) medium and growth activation was initiated by adding fresh medium with 10% FCS during microgravity exposure. Four days after serum activation, the cells were fixed before return to normal Earth gravity. Ground controls were treated in parallel with the flight samples in identical equipment. On landing, cell number, cell cytoskeleton, glucose utilization, and prostaglandin synthesis in flight (n = 4) and ground controls (n = 4) were examined. The flown osteoblasts grew slowly in microgravity with total cell number significantly reduced (55 +/- 6 vs 141 +/- 8 cells per microscopic field). The cytoskeleton of the flight osteoblasts had a reduced number of stress fibers and a unique abnormal morphology. Nuclei in the ground controls were large and round with punctate Hoechst staining of the DNA nucleosomes. The flight nuclei were 30% smaller than the controls (P < 0.0001) and oblong in shape, with fewer punctate areas. Due to their reduced numbers, the cells activated in microgravity used significantly less glucose than ground controls (80.2 +/- 0.7 vs 50.3 +/- 3.7 mg of glucose/dl remaining in the medium) and had reduced prostaglandin E(2) (PGE(2)) synthesis when compared to controls (57.3 +/- 17 vs 138.3 +/- 41 pmol/ml). Cell viability was normal since, on a per-cell basis, glucose use and prostaglandin synthesis were comparable for flight and ground samples. Taken together, these data suggest that growth activation in microgravity results in reduced growth, causing reduced glucose utilization and reduced prostaglandin synthesis, with significantly altered actin cytoskeleton in osteoblasts. (C) 1996 Academic Press, Inc.