STRETCH-INDUCED CELL MORPHOGENEISI : MOLECULAR MECHANISM OF DIRECTIONSENSITIVITY AND POLARITY FORMATION

拉伸诱导的细胞形态发生：方向敏感性和极性形成的分子机制

• 批准号: 08458206
• 负责人: SOKABE Masahiro
• 金额: $ 5.44万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08458206/
• 关键词: Endothelial cells; Stretch stimuli; Morphological response; Cell polarity; signaling cascade; SA channel; Focal adhesion; Tyrosine phosphorylation; 血管内皮細胞; 一軸伸展刺激; 接着班蛋白質; src; 細胞骨格; 血管内皮細胞、; 機械刺激、; 形態応答、; 機械受容チャネル、; 接着斑、; チロシン燐酸化、

Endothelial cells exhibit spindle like shape aligning their longtude parallel with vessel running. This peculiar shape and alignment is isgnificant to prevent the cells from being pealed off by blood flow. However, cultured endothelial cells do not show such a shape and alignment, It is known that mechanical stresses onto the cells, like shear stress and periodic circumferential stretch, by pulsative blood flow are enough to induce such a morphology in endothelial cells. It has been also suggested that cytoskeletons and adhesion molecules contribute to this morphogenesis. The altimate goal of this project is to elucidate the signaling cascade in the stretchOinduced morphogenesis in cultured endothelial cells and to understand the molecular mechanism underlying the formation of two dimensional polarity in the cell. Using Ca^<2+>imaging, patch clamp, biochemical and molecular biological techniques, we could identify the major signaling cascade in the stretch-induced morphogenesis as follows : <uniaxial periodic stretch* activation of SA channels* intracellular C_amobilization* activation of calcinyrin* activation of tyrosine kinase, src, * tyrosine phosphorylation of adhesion proteins* reorganization of stress fibers and forcal adhesion* morphological change>. However, as the stretch activated Ca^<2+> increase was spatially uniform, this may not be the cause of the cell polarity. On the other hand, tyrosine phosphorylated proteins favored to distribute at the elongating portion of the cell. Hence, it is possible that there is another signaling mechanism flowing from adhesion plaque (integrin), upon which mechanical forces are directly imposed, to intracellular space. This mechanism may along with the former signaling mechanism contribute to the formation of the cell polarity through the regulation of tyrosine phosphorylation of focal adhesion proteins. Next step of our project should be to prove this hypothesis.

内皮细胞呈纺锤形，其长度与血管走向平行。这种特殊的形状和排列方式对于防止细胞被血流剥离非常重要。然而，培养的内皮细胞不显示这样的形状和排列。已知通过脉动血流施加到细胞上的机械应力（如剪切应力和周期性周向拉伸）足以在内皮细胞中诱导这样的形态。也有人认为，细胞骨架和粘附分子有助于这种形态发生。本课题的最终目的是阐明牵张诱导的内皮细胞形态发生中的信号级联，并了解细胞内二维极性形成的分子机制。利用Ca^<2+>成像、膜片钳、生物化学和分子生物学技术，我们可以确定牵张诱导的形态发生中的主要信号级联反应如下：<单轴周期性拉伸 * SA通道的激活 * 细胞内C_amobilization* 钙调素的激活 * 酪氨酸激酶src的激活 * 粘附蛋白的酪氨酸磷酸化 * 应力纤维和forcal粘附的重组 * 形态学变化>。然而，由于牵张激活的Ca^2+增加在空间上是均匀的，这可能不是细胞极性的原因。而酪氨酸磷酸化蛋白则倾向于分布在细胞的伸长部位。因此，有可能存在另一种信号传导机制从粘附斑（整联蛋白）流向细胞内空间，机械力直接施加在粘附斑上。这种机制可能与前一种信号传导机制沿着，通过调节粘着斑蛋白酪氨酸磷酸化而促进细胞极性的形成。我们项目的下一步应该是证明这个假设。

项目成果

Qi Z., Sokabe, M.: "Dynamic properties of individual water molecules in a hydrophobic pore lined with acy1 chains: a molecular dynamics study." Biophys Chem. (in press).

Qi Z.，Sokabe，M.：“内衬 acy1 链的疏水孔中单个水分子的动态特性：分子动力学研究。”

Qi Z., Sokabe, M.: "Dynamic properties of individual water molecules in a hydrophobic pore lined with acy1 chains : a moleculardynamics study." Biophys.Chem.(in press).

Qi Z.，Sokabe，M.：“内衬 acy1 链的疏水孔中单个水分子的动态特性：分子动力学研究。”

Kobuke,Y.,Tanaka,Y.,Sokabe,M.: "Artificial non-peptide single ion channels." Progr Cell Res.6. 167-188 (1996)

Kobuke,Y.、Tanaka,Y.、Sokabe,M.：“人工非肽单离子通道。”

Okada,H.,Yoshida,J.,Sokabe,M.,Wakabayashi,T.,Hagiwara,M.: "Suppression of CD44 expression decreases migartion and invasion of human glioma cells." Int J Cancer Res. 66. 255-260 (1996)

Okada,H.、Yoshida,J.、Sokabe,M.、Wakabayashi,T.、Hagiwara,M.：“抑制 CD44 表达可减少人胶质瘤细胞的迁移和侵袭。”

Qi Z., Sokabe,M.: "Dynamic properties of individual water molecules in a hydrophobic pore lined with acyl chains : a molecular dynamics study." Biophys Chem. (in press).

Qi Z.，Sokabe，M.：“内衬酰基链的疏水孔中单个水分子的动态特性：分子动力学研究。”