RHO KINASE REGULATION OF CYTOSKELETAL REMODELING IN THE A7R5 SMOOTH MUSCLE CELL

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 这项研究将集中于肌动蛋白和肌球蛋白重塑在收缩的A7r5平滑肌细胞中的作用和调节，并与主动脉平滑肌组织进行比较。我们以前已经提供了α-肌动蛋白和β-肌动蛋白以及平滑肌肌球蛋白II细胞骨架结构不同重构的证据。然而，调控这种差异性重构的机制(S)尚不清楚。数据表明，肌动蛋白-肌动蛋白对佛波醇刺激的重新分配比β-肌动蛋白向足体的重新分配更敏感。肌球蛋白的分布似乎跟随着细胞骨架的α-肌动蛋白成分的变化。此外，初步证据表明，以前被证明可以对抗大鼠主动脉平滑肌组织收缩的发展和维持的Rho激酶抑制，阻止了足体的α-肌动蛋白重塑和α-肌动蛋白应激电缆的重建。这一证据支持肌动蛋白细胞骨架的不同重塑和可能不同的调控机制的假说。该项目的主要目标是确定抑制Rho激酶对A7r5细胞肌动蛋白和肌球蛋白重塑的影响，并将其与先前在主动脉平滑肌组织中观察到的效果进行比较。初步证据表明，几种Rho激酶可能对α-肌动蛋白有选择性作用，因此支持我们的假设，即α-肌动蛋白和β-肌动蛋白细胞骨架的不同重塑。这表明，可能有几种可能的生化途径调节着平滑肌的重塑和收缩。如果细胞骨架的激酶调控是不同的，这将支持我们的收缩模型，该模型在平滑肌收缩过程中为α-和β-肌动蛋白分配不同的角色。此外，在两年的资助期内，该项目将吸引众多本科生和研究生参与研究，增进他们对科学过程的理解，并使他们能够为鲜为人知的生理机制做出贡献。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This investigation will focus on the role and regulation of actin and myosin remodeling in the contracting A7r5 smooth muscle cell in comparison to aortic smooth muscle tissue. We have previously provided evidence of differential remodeling of the alpha- and beta- actin as well as smooth muscle myosin II cytoskeletal structures. However, the mechanism(s) regulating this differential remodeling is not understood. Data suggests that the redistribution of actin- actin to podosomes is more sensitive to phorbol stimulation than redistribution of beta-actin to the podosomes. Myosin distribution appears to follow changes in alpha-actin component of the cytoskeleton. Also, preliminary evidence suggests that Rho kinase inhibition, previously shown to antagonize the development and maintenance of contraction in rat aortic smooth muscle tissue, blocked alpha-actin remodeling to the podosomes and re-establishment of alpha-actin stress cables. This evidence supports the hypothesis of differential remodeling and potentially different regulatory mechanisms governing the actin cytoskeleton. The major objective of the proposed project is to determine the effects of Rho kinase inhibition on actin and myosin remodeling in A7r5 cells and compare this to the effect previously observed in aortic smooth muscle tissue. Preliminary evidence suggests several Rho kinase may have a selective effect on alpha-actin and therefore support our hypothesis of differential remodeling of the alpha-actin and beta-actin cytoskeleton. This would suggest that there may be several possible biochemical pathways regulating remodeling and therefore contraction in smooth muscle. If kinase regulation of cytoskeleton is differentially regulated, it would support our model of contraction which assigns different roles to alpha- and beta-actin during smooth muscle contraction. Also, over the two year funding period, this project will engage numerous undergraduate and graduate students in research, enhancing their understanding of the scientific process and allowing them to make contributions to a poorly understood physiological mechanism.