Simvastatin to Retard Degenerative Disc Disease

描述（由申请人提供）：目前退行性椎间盘疾病的医学治疗方法有限，并且在稳定新脊柱结构的同时移除扰动椎间盘的可用手术治疗成本高且具有侵入性，并伴有相关的发病风险。领先的研究集中在微创方法，以扭转或防止椎间盘退变。大多数人依赖昂贵的新药和设备。然而，使用移动的假体或甚至工程化组织的新的修复带来了新的一系列并发症和障碍。随着重组治疗蛋白的最新进展，椎间盘的生物修复或再生已经被提倡。包括骨形态发生蛋白（BMP）在内的多种生长因子在生物修复方面的研究已初步证实其对椎间盘细胞的合成代谢作用。尽管如此，这些重组人生长因子仍然存在问题，因为它们或者参与椎间盘处不希望的血管向内生长，或者它们的给定剂量通常远远超过生理水平以获得有效性。此外，使用这些生物因子的成本尚未达到负担得起的水平。这项拟议的研究将调查一种治疗椎间盘退变的方法，其成本可能会大幅降低。我们以前的工作表明，常用的降胆固醇药物辛伐他汀刺激内源性BMP-2的表达，并反过来增加体外培养的椎间盘细胞的软骨形成表型表达，并且当将辛伐他汀装载在热敏性、可生物降解的聚合物中注射到我们的大鼠模型中的扰动椎间盘的髓核中时，由刺伤诱导的椎间盘退变被完全逆转。在本研究中，我们希望将我们的研究扩展到定义的IVD退变动物模型，以进一步表征使用辛伐他汀作为他汀类药物的标签外适应症专门用于治疗退行性椎间盘疾病的安全性和有效性。我们推测，辛伐他汀从可注射的可降解聚合物中的控释将延缓椎间盘退变的进展，并可能进一步再生椎间盘内组织。我们将在Sprague-Dawley大鼠尾椎的预定水平处对椎间盘使用刺伤（纤维环切开术）扰动，以开发将根据成像、形态学和组织学评估进行分级的每种椎间盘退变。纤维环结构完整的等级将指示聚合物中负载辛伐他汀的注射剂。药物剂量将以递增方式给药，并持续至预定处死时间点，以表征最佳剂量以及有效持续时间。最后，将利用尤卡坦小型猪模型进一步评估经辛伐他汀治疗后，扰动椎间盘是否可以恢复固有的生物力学功能和椎间空间的解剖特征，为未来临床试验的开发和实施提供见解。 公共卫生相关性：一种流行的降胆固醇药物辛伐他汀最近被研究刺激骨细胞分泌一种生长因子，可以增加骨组织的生长。这种机制被认为是至关重要的，以及椎间盘细胞再生组织物质。因此，本研究拟观察辛伐他汀注射入退变椎间盘以延缓退变椎间盘疾病进展并帮助修复异常组织的可能性。

DESCRIPTION (provided by applicant): Current medical treatments for degenerative disc disease are limited and the available surgical treatments to remove the perturbed discs while stabilizing the new spinal construct are costly and invasive with associated risks of morbidity. Leading research is focused on less invasive methods to reverse or prevent intervertebral disc degeneration. Most rely on costly new drugs and devices. However, new implantations with mobile prostheses or even engineered tissues have brought a new spectrum of complications and hurdles to be addressed. Biological repair or regeneration of the intervertebral disc has been advocated with recent advances in recombinant therapeutic proteins. Many growth factors including bone morphogenetic protein (BMP) have been investigated on the aspect of biological repair and have been proved preliminarily with their anabolic effects on the intervertebral disc cells. Nonetheless, concerns still remain with these recombinant human growth factors since they either participate in undesired blood vessel ingrowth at the intervertebral disc or their given doses are normally much over the physiological levels to obtain effectiveness. In addition, costs for using these biofactors have not yet reached affordable. The proposed study will investigate a treatment for disc degeneration with the potential for substantially lower cost. Our previous work indicated that the common cholesterol-lowing drug simvastatin stimulated endogenous BMP-2 expression and in turn increased the chondrogenic phenotype expression of intervertebral disc cells cultured in vitro, and also the disc degeneration induced by a stab injury was fully reversed when injecting simvastatin that was loaded in a thermosensative, biodegradable polymer into nucleus pulposus of the perturbed discs in our rat model. In this study, we would like to extend our investigation to the defined animal models with IVD degeneration to further characterize the safety and effectiveness of using simvastatin specifically for the treatment of degenerative disc disease as an off-label indication of statins. We hypothesize that controlled release of simvastain from an injectable, degradable polymer will retard the progress of disc degeneration and may further regenerate intradiscal tissues. We will use stab injury (annulotomy) perturbation on intervertebral discs at predetermined levels of Sprague-Dawley rat's caudal spine to develop each category of disc degeneration that will be graded according to imaging, morphological and histological assessments. Grades with intact structure of annulus fibrosus will be indicated to the injection with simvastatin loaded in the polymer. Doses of the drug will be administered in an escalating manner and will be last until predetermined sacrifice time points to characterize the optimal dosage as well as the effective duration. Finally, a Yucatan minipig model will be utilized to further evaluate whether perturbed discs can restore the inherent biomechanical functions and anatomical features of interbody space after being treated with simvastatin to provide an insight in the development and implementation of future clinical trials. PUBLIC HEALTH RELEVANCE: A prevalent cholesterol-lowing drug simvastatin has recently been investigated to stimulate bone cells to secrete a growth factor that can augment bone tissue growth. This mechanism is thought to be critical as well for cells in the intervertebral disc to regenerate tissue substances. It is then proposed in this study to observe the potential to inject simvastatin into degenerative disc to retard the progression of degenerative disc disease and also help repair the aberrant tissues.