【作者】 郭志良；

【导师】 周跃；

【作者基本信息】 第三军医大学 ， 外科学， 2006， 博士

【摘要】 研究背景下腰痛是一个重要的公共卫生问题,给家庭和社会带来沉重的负担。虽然引起下腰痛的原因很多,但是椎间盘退变仍是主要因素。目前临床应用的治疗方法主要解决临床症状,而非针对退变早期的病理过程,并未延缓或逆转椎间盘退变。关于椎间盘退变的原因,虽然做出了许多有益的探讨,但其确切发病机制仍然不清楚。只有在全面了解椎间盘退变机理之后,才可能进一步研究阻止其退变甚或使其再生的方法。目前的观点认为,椎间盘退变是一个由生物化学和生物力学因素相互作用的复杂病理过程。椎间盘始终处于负荷状态,尤其是椎间盘纤维环细胞总是受到不同形式的拉伸应力作用。纤维环蛋白多糖含量的下降和/或成分的改变,可以引起纤维环的退变,进而导致整个椎间盘退变的发生。Aggrecan是椎间盘中蛋白多糖的主要成分。小鼠的Aggrecan基因突变后,可以发生椎间盘的退变。同时椎间盘蛋白多糖的更新速率较快,对外界刺激更为敏感。在本实验中采用周期性张应变模拟作用于纤维环的张应力情况,观察其对椎间盘纤维环细胞蛋白多糖表达的影响。力学信号转化为生物化学信号是一个非常复杂的过程,涉及到很多细胞内、外成分。在很多类型的细胞中,力学刺激可以使细胞内钙离子浓度升高和ERK1/2发生磷酸化,因此,钙离子和ERK1/2信号通路被认为是细胞力学信号转导的共同通路。至于纤维环细胞是如何将机械应力这一力学信号转化成为细胞的生物化学信号,目前对其过程了解甚少。本实验对纤维环细胞力学信号转导的过程进行探讨,旨在揭示机械应力在纤维环退变中的作用,从生物力学角度探讨椎间盘退变的发生机理。实验方法1.大鼠椎间盘纤维环细胞的培养和鉴定采用酶消化法分离大鼠椎间盘纤维环细胞,进行单层培养,观察其形态结构和生物学特性,通过甲苯胺蓝、免疫细胞化学和碱性磷酸酶染色、透射电镜观察等方法对其表型进行鉴定。2.种植于硅橡胶膜上的大鼠纤维环细胞的表型特征研究更多还原

【Abstract】 BACKGROUNDLow back pain is a significant public health issue in our society, which accounts for much individual suffering and societal costs. Although there are multiple causes involved, degeneration of intervertebral disc has been implicated as the leading pathogenic process. Currently, the only available treatment modalities for disc-related low back pain focus on alleviating symptoms rather than addressing the underlying cause of degeneration. It is likely that clinical outcomes for patients with painful intervertebral disc degeneration would improve if therapies were developed that could slow, halt or reverse this process. While the factors that initiate and perpetuate disc degeneration are not well understood, it is a commonly held belief that disc degeneration is a multifactoral process involving both biochemical and biomechanical contributions. Within the disc, it is under overload from the forces of the muscles constrain motion and hydrostatic pressures at certain time, even at rest. Especially, annulus fibrosus (AF) cells are constantly subject to different stretch stresses in duration, intensity, and frequency in vivo. It is been shown in recent years that sensitivity to mechanical forces is a general property of all living tissues and all cultured cells. Many believe that disc degeneration has a cellular basis. So it is essential to study the effects of biomechanical stimulations on annulus fibrosus cells.Some evidence indicates that intervertebral disc degeneration begins with a progressive decrease in proteoglycan content. The major proteoglycan of the disc is aggrecan, which is thought to play a role in maintaining the collagen network and in collagen fibrillogenesis. Because aggrecan has a rapid turnover, the decreased production of aggrecan could significantly induce disc degeneration. Furthermore, researchers have shown that an autosomal recessive mutation in the aggrecan gene leads to intervertebral disc degeneration in mice. Taken together, it is shown that proteoglycan plays a main role in disc degeneration.更多还原