Zhu Zhengya, He Zhongyuan, Tang Tao, Wang Fuan, Chen Hongkun, Zhou Jiaxiang, Lin Chengkai, Chen Guoliang, Wang Jianmin, Li Jianfeng, Liu Xizhe, Zhou Zhiyu, Liu Shaoyu
Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
Department of Orthopaedic Surgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, China.
Front Physiol. 2023 Oct 11;14:1225898. doi: 10.3389/fphys.2023.1225898. eCollection 2023.
Heterotopic ossification of tendons and ligaments (HOTL) is a common clinical condition characterized by the absence of discernible features and a lack of effective treatment. experiments have demonstrated that mechanical stimulation can induce cell differentiation toward osteogenesis, thereby promoting heterotopic ossification. Currently, there are few experimental designs aimed at inducing ligament stretching in mice, and the mechanism of heterotopic ossification may not entirely mirror that observed in clinical cases. Therefore, there is an urgent imperative to develop a novel and feasible animal model. In this study, all the gene deficiency mice (a mouse model with heterotopic ossification of multiple ligaments) were divided into three groups: the control group, the spinal brake group, and the hyperactive group (treadmill training group). An external spinal fixation device was designed to restrict mice's spinal flexion and extension at 6 weeks of age. The brace was adjusted weekly according to the changes in the size of the mice. Additionally, treadmill training was used to increase activity in the spinal ligaments and Achilles tendons of the mice. Micro-CT scanning and HE staining were performed at 12, 20, and 28 W to evaluate the degree of ossification in the spinal ligament and Achilles tendon. What's more, As one of the mechanical stimulation transduction signals, YAP plays a crucial role in promoting osteogenic differentiation of cells. Immunofluorescence was utilized to assess YAP expression levels for the purpose of determining the extent of mechanical stimulation in tissues. Our findings showed that a few ossification lesions were detected behind the vertebral space of mice at 8 weeks of age. Spinal immobilization effectively restricts the flexion and extension of cervical and thoracic vertebrae in mice, delaying spinal ligament ossification and reducing chronic secondary spinal cord injury. Running exercises not only enhance the ossification area of the posterior longitudinal ligament (PLL) and Achilles tendons but also exacerbate secondary spinal cord injury. Further immunofluorescence results revealed a notable increase in YAP expression levels in tissues with severe ossification, suggesting that these tissues may be subjected to higher mechanical stimulation. Mechanical stimulation plays a pivotal role in the process of heterotopic ossification in tissues. Our study provided valid animal models to further explore the pathological mechanism of mechanical stimulation in HOTL development.
肌腱和韧带的异位骨化(HOTL)是一种常见的临床病症,其特征是缺乏可识别的特征且缺乏有效的治疗方法。实验表明,机械刺激可诱导细胞向成骨方向分化,从而促进异位骨化。目前,针对诱导小鼠韧带拉伸的实验设计很少,而异位骨化的机制可能并不完全反映临床病例中观察到的情况。因此,迫切需要开发一种新颖且可行的动物模型。在本研究中,所有基因缺陷小鼠(一种具有多条韧带异位骨化的小鼠模型)被分为三组:对照组、脊柱制动组和多动组(跑步机训练组)。设计了一种外部脊柱固定装置,在小鼠6周龄时限制其脊柱的屈伸。每周根据小鼠体型变化调整固定装置。此外,使用跑步机训练来增加小鼠脊柱韧带和跟腱的活动。在第12、20和28周进行显微CT扫描和苏木精-伊红(HE)染色,以评估脊柱韧带和跟腱的骨化程度。此外,作为机械刺激转导信号之一,YAP在促进细胞成骨分化中起关键作用。利用免疫荧光评估YAP表达水平,以确定组织中机械刺激的程度。我们的研究结果表明,在8周龄小鼠的椎间隙后方检测到一些骨化病变。脊柱固定有效地限制了小鼠颈椎和胸椎的屈伸,延缓了脊柱韧带骨化并减少了慢性继发性脊髓损伤。跑步运动不仅增加了后纵韧带(PLL)和跟腱的骨化面积,还加剧了继发性脊髓损伤。进一步的免疫荧光结果显示,在骨化严重的组织中YAP表达水平显著增加,表明这些组织可能受到更高的机械刺激。机械刺激在组织异位骨化过程中起关键作用。我们的研究提供了有效的动物模型,以进一步探索机械刺激在HOTL发展中的病理机制。