Actin and microtubule cytoskeletons of the processes of 3D-cultured MC3T3-E1 cells and osteocytes
Actin and microtubule cytoskeletons of the processes of 3D-cultured MC3T3-E1 cells and osteocytes
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DOI：
10.1007/s00774-006-0745-5
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发表时间：
2007-05-01
影响因子：
3.3
通讯作者：
Takano-Yamamoto, Teruko
中科院分区：
文献类型：
--
作者：
Murshid, Sakhr A.;Kamioka, Hiroshi;Takano-Yamamoto, Teruko
细胞形状是细胞功能的最关键的决定因素，并潜在地受到细胞细胞骨架组成的组织的影响。据报道，三维培养的成骨细胞具有与骨细胞非常相似的形态，最显著的是包括突起的形成。我们之前已经在二维培养中展示了成骨细胞和骨细胞中细胞骨架成分的关键差异。现在，我们利用成骨细胞系MC3T3-E1的3D培养，以及在胶原胶中生长的原代骨细胞，将这种研究扩展到3D培养的成骨细胞和骨细胞的细胞骨架成分。用IMARIS软件进行肌动蛋白、纤毛蛋白、α-肌动蛋白、肌球蛋白、原肌球蛋白和微管的三维荧光图像重建。肌动蛋白、纤毛蛋白、α-肌动蛋白、肌球蛋白和原肌球蛋白均存在于两种细胞的突起中，但纤毛蛋白和肌球蛋白在不同类型细胞中的分布模式不同。微管仅分布于骨细胞突起的近端，但延伸至MC3T3-E1细胞突起的全长。微管对MC3T3-E1细胞突起的完整和形成是必不可少的，但骨细胞突起依赖于肌动蛋白。这些结果表明，在3D培养的MC3T3-E1细胞和3D培养的原代骨细胞的过程中，肌动蛋白和微管细胞骨架之间存在着显著的差异。3D培养的成骨细胞突起和骨细胞树突的细胞骨架的这些差异表明，成骨细胞突起可能具有不同于骨细胞树突网络的功能作用。
Cell shape is the most critical determinant of cell function and is potentially influenced by the organization of a cell's cytoskeletal components. It has been reported that three-dimensionally cultured osteoblasts have a morphology that closely resembles that of osteocytes, most notably including formation of processes. We have previously shown the critical differences between cytoskeletal components in osteoblasts and osteocytes in two-dimensional culture. We have now extended that investigation to the cytoskeletal components of 3D-cultured osteoblasts and osteocytes using 3D cultures of the osteoblast cell line, MC3T3-E1, and primary osteocytes grown in collagen gel. Three-dimensional fluorescent image reconstructions for actin, fimbrin, alpha-actinin, myosin, tropomyosin, and microtubules were made using IMARIS software. Actin, fimbrin, alpha-actinin, myosin, and tropomyosin all appeared in the processes of both cell types, but fimbrin and myosin showed differences in their distribution patterns between cell types. Microtubules were limited in distribution to the proximal region of osteocyte processes but extended the entire length of MC3T3-E1 cell processes. Microtubules were essential for the integrity and formation of MC3T3-E1 cell processes, but osteocyte processes were dependent on actin. These results showed that there are significant differences between the actin and microtubule cytoskeletons in the processes of 3D-cultured MC3T3-E1 cells and in the processes of 3D-cultured primary osteocytes. These differences in the cytoskeleton of the processes of 3D-cultured osteoblasts and of osteocyte dendrites suggest that osteoblast processes may have a different functional role than the osteocyte dendritic network.