Role of Mechanical Forces on Beta-Catenin of Aged Intervertebral Discs

描述（由申请人提供）：超生理活动、衰老和遗传因素可引发椎间盘退变，其特征包括但不限于水合作用丧失、基质成分浓度改变、机械僵硬和最终的背痛。尾盘上的过度机械负荷，类似于剧烈抬起时产生的负荷，会诱发椎间盘退变。然而，利用机械载荷对退变的研究侧重于描述对椎间盘结构及其基质成分的影响，而很少深入了解其潜在机制。此外，椎间盘退变的风险随着年龄的增长而增加，因此，评估年龄对有害负荷反应的影响是很重要的。β -连环蛋白受典型的Wnt通路调控，并被认为参与了椎间盘的分解代谢。细胞外Wnt配体是

DESCRIPTION (provided by applicant): Supra-physiological activity, aging and genetic factors may initiate intervertebral disc degeneration, which is characterized by, but not limited to, loss f hydration, altered concentrations of matrix constituents, mechanical stiffening and ultimately back pain. Excessive mechanical loads on tail discs, as analogous to those engendered by strenuous lifting, induce aspects of disc degeneration. However, studies of degeneration using mechanical loading focus on describing the consequences to disc structure and its matrix constituents with little insight into the underlying mechanism(s). Further, the risk of disc degeneration increases with age and therefore, it is important to evaluate the influence of aging on the response to deleterious loading. beta-Catenin is regulated by the canonical Wnt pathway and is putatively involved in the catabolism of intervertebral discs. Extracellular Wnt ligands are upstream regulators of transcription factor beta-catenin, which accumulates in the cells of human degenerated discs, and cells from canines known to have an age-related propensity for degeneration. Suppression of beta-catenin signaling in chondrocytes immersed in inflammatory cytokines mitigates the expression of catabolic markers, suggesting that targeting this pathway may have therapeutic potential. We will combine our experience with murine loading models and genetic tools to determine the role of beta-catenin activation in disc degeneration induced by mechanical loading. The structural-, cellular- and molecular- level consequences of mechanical overloading in a reporter mouse of beta-Catenin activation and a conditional knockout mouse of beta-catenin in young-adult and aged mice. This research will impact the field of intervertebral disc mechano-biology by identifying the involvement of beta-catenin in a model of disc degeneration and help provide a mechanism upon which to develop treatments capable of curbing or preventing disc degeneration.