Identification of mechano-sensitive pathways in intervertebral disc cells

椎间盘细胞中机械敏感通路的鉴定

• 批准号: RGPIN-2015-06185
• 负责人: Seguin, Cheryle
• 金额: $ 2.77万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613992
• 关键词: Identification; mechano; sensitive; pathways; intervertebral

Intervertebral discs form the soft connective tissue joints located along the length of the spine - required for spinal stabilization, load bearing, and movement. The major function of the intervertebral disc is to act as a shock absorber during mechanical loading. It is composed of distinct yet interdependent tissues including the central nucleus pulposus, which is highly hydrated and provides turgor to withstand compressive loading, and the outer annulus fibrosus which contains the nucleus pulposus and provides resistance to tensile strain. Although daily mechanical loading provides necessary feedback to cells of the disc to maintain the tissue’s integrity, excessive loading contributes to disc degeneration by activating a cascade of non-reversible changes in disc cells that ultimately lead to an inability of the disc to fulfill its physiological function. The responses of specific disc cells to mechanical loading are therefore essential to maintaining a functional disc tissue. The effects of different types of mechanical loading (resulting from normal movement vs. exposure to vibration) on the distinct cell types of the disc are poorly understood, as are the cellular pathways that regulate these responses. The objective of these studies is to characterize the effects of mechanical loading on specific cell types of the disc, and explore which signaling pathways mediate the cellular response. We will use a genetically engineered mouse model that uses fluorescent cell markers to distinguish nucleus pulposus cells from annulus fibrosus cells. Cells grown in the lab will be subjected to mechanical loading in the form of either cyclic strain (physiological loading) or vibration (to model exposure to heavy machinery or vibration platforms) and the response of these cell types will be quantified through a series of experiments. These studies will give us a better fundamental understanding of how different cell types of the intervertebral disc respond to mechanical loading, information that is key to understanding how the disc maintains its structural integrity. Deciphering the pathways that control intervertebral disc mechanobiology will facilitate the development of tissue engineering strategies to recreate disc formation in vitro.

椎间盘形成了沿着脊柱长度的软结缔组织关节-脊柱稳定、承重和运动所需。椎间盘的主要功能是在机械负荷期间充当减震器。它由不同但相互依赖的组织组成，包括高度水合并提供膨压以承受压缩载荷的中央髓核，以及包含髓核并提供抗拉伸应变的外部纤维环。尽管日常机械负荷为椎间盘细胞提供了必要的反馈以保持组织的完整性，但过度负荷通过激活椎间盘细胞中的级联不可逆变化而导致椎间盘退变，这最终导致椎间盘无法实现其生理功能。因此，特定椎间盘细胞对机械负荷的反应对于维持功能性椎间盘组织至关重要。不同类型的机械负荷（由正常运动与暴露于振动引起）对椎间盘不同细胞类型的影响知之甚少，调节这些反应的细胞通路也是如此。 这些研究的目的是表征机械负荷对椎间盘特定细胞类型的影响，并探索哪些信号通路介导细胞反应。我们将使用一种基因工程小鼠模型，该模型使用荧光细胞标记来区分髓核细胞和纤维环细胞。在实验室中生长的细胞将经受以循环应变（生理负载）或振动（以模拟暴露于重型机械或振动平台）形式的机械负载，并且这些细胞类型的响应将通过一系列实验来量化。这些研究将使我们更好地了解椎间盘的不同细胞类型如何对机械负荷做出反应，这些信息是理解椎间盘如何保持其结构完整性的关键。破译控制椎间盘机械生物学的途径将促进组织工程策略的发展，以在体外重建椎间盘形成。