PI3Ks/Rho/MLCP在肌筋膜疼痛扳机点肌小节中的表达及机制研究

Myofascial trigger points (MTrPs), which defined as one or several hyperirritable contraction knots in sarcomeres in a muscle taut band or nodules, have been considered as the major cause of chronic myofascial pain syndrome (MPS) and the important site for treatment in pain clinic. We previous demonstrated that MTrPs in the referred muscle were abnormal contractive sarcomeres. The protein molecular mechanisms of abnormal contraction sarcomeres in MTrPs in myofascial pain syndrome remain unclear.. Phosphoinositide 3 kinases (PI3Ks), Rho family (RhoA) and myosin light chain phosphatase (MLCP) play an important role in the regulation of calcium dependent sensitization in vascular smooth muscle contraction. RhoA was considered to be playing an important role of “molecule switch” in the intracellular signal transduction. We previous demonstrated that receptor tyrosine kinase family (RTKs) EphrinB2 and RhoA were involved in the regulation of contractive knots in sarcomeres of MTrPs, therefore, we hypothesis that “Rho family might be involved in the regulation of abnormal contraction sarcomeres of MTrPs in myofascial pain syndrome patients”.. To test this hypothesize , we try to investigate the pathophysiological mechanisms of MTrPs in the taut band or nodules, by tissue biopsy from the trapezius muscle or gluteus medius muscle) on MPS patients, MTrPs rat model and siRNA methods, using histopathology, immunohistochemical staining, hybridization in situ, laser scanning confocal microscopy and RT-PCR methods, based on Rho family, the upstream effectors PI3Ks and the downstream effectors of MLCP, and to elucided the protein molecular mechanisms in sarcomere in MTrPs and provide a new therapautic targets for better management of myofascial pain syndrome patients.

肌筋膜疼痛扳机点（MTrPs）由一个或多个异常收缩的肌小节组成，是引起慢性疼痛反复发作的主要原因，其病理生理机制尚未完全阐明。研究证实：磷脂酰肌醇3激酶（PI3Ks）、Rho家族（RhoA）和肌球蛋白轻链磷酸酶（MLCP）参与血管平滑肌钙敏感性收缩调节。我们前期研究发现：酪氨酸受体激酶(RTKs)家族中EphrinB2及PI3Ks下游蛋白RhoA在MTrPs肌小节中呈异常表达，推测：MTrPs肌小节异常收缩可能与Rho家族的“分子开关”作用有关。.我们拟通过MTrPs活检、实验动物模型、不同抑制剂及基因干扰等方法，运用组织病理、免疫组化、原位杂交、免疫双荧光及RT-PCR技术，分别从组织、细胞及分子水平，以Rho家族为重点，观察其上游PI3Ks和下游MLCP调节蛋白亚型在MTrPs肌小节异常收缩病理生理作用，探明MTrPs肌小节异常收缩的蛋白分子机制，为肌筋膜疼痛综合征治疗提供新靶点。

肌筋膜疼痛综合征（Myofascial pain syndrome，MPS）是临床上最常见的慢性疼痛性疾病之一。其特点是在患者相应的肌筋膜部位存在一个或多个肌筋膜扳机点（Myofascial trigger points，MTrPs）。MTrPs的本质是一个或多个异常收缩的肌小节，但其具体发生机制尚未明确。. 团队首次在人体MPS病人MTrPs组织上，利用现代蛋白组学技术，对其异常收缩肌小节的炎症机制，从RTKs家族差异蛋白进行创新性探索，并用动物实验进行功能验证。研究发现：（1）MTrPs 由一个或多个异常收缩的肌小节组成，没有明显炎症细胞浸润和纤维化，证明了MTrPs部位并非细菌性炎症或粘连。因此，临床上使用抗炎药物治疗MPS效果不佳；（2）现代蛋白组学发现：在MTrPs中，RTKs中有15个蛋白磷酸化表达显著上调，2个蛋白磷酸化表达显著下调。其中，亚家族成员EphB1/ EphB2/ EphB3在异常收缩肌小节上磷酸化表达明显升高，可能参与调节MTrPs部位肌节的异常收缩；（3）收缩调节蛋白Rho家族中RhoA/rac1而非Cdc42，发生不同程度的转膜激活，参与调节MTrPs部位肌节的异常收缩；(3) EphB1/FGFR可能是MTrPs治疗的关键靶点，其中FGFR可能是通过PI3K-AKT 信号调节MTrPs的发展。. 这些探索性研究成果首次揭示了人体MTrPs的组织病理学改变，并验证了EphB1/FGFR可能在MTrPs的肌小节异常收缩部位发挥作用，是MTrPs治疗的关键靶点。MTrPs是多个蛋白相互作用形成的局部病理微环境。接下来需要进一步利用高通量的蛋白组学检测其他差异蛋白，探究其可能的功能以及相互之间的调节作用。