PTHrP-HDAC4信号通路在大骨节病软骨细胞分化障碍中的作用及分子机制

The cartilage damage of Kashin-Beck disease (KBD) involves chondrocyte terminal differentiation disorder but its molecular mechanism remains unclear. The PTHrP-HDAC4 signaling pathway plays a key role in the maturation and differentiation of chondrocytes. Abnormalities in this signaling pathway may lead to chondrogenic abnormalities and degenerative changes in articular cartilage of humans and animals. In order to clarify the potential mechanism of chondrocyte terminal differentiation disorder of KBD and its relationship with suspected etiology. The main contents of this study include: 1) to determine the expression characteristics of genes and proteins related to the PTHrP-HDAC4 signaling pathway in cartilage and chondrocytes of KBD; 2) to determine the role and regulatory mechanism of the PTHrP-HDAC4 signaling pathway in chondrocyte terminal differentiation disorder of KBD; 3) to determine the role of T-2 toxin and HT-2 toxin and/or low selenium in the chondrocyte terminal differentiation disorder of KBD through the PTHrP-HDAC4 signaling pathway. The expected results of this study will reveal the mechanism of the PTHrP-HDAC4 signaling pathway in chondrocyte terminal differentiation disorder of KBD and its etiological relationship with environmental risk factors, and will provide the theoretical and experimental basis for further study on the etiology and pathogenesis of KBD and search for the potential intervention targets.

大骨节病软骨损伤涉及软骨细胞终末分化障碍但其分子机制仍不明确。PTHrP-HDAC4信号通路在软骨细胞成熟分化中具有关键调控作用，该信号通路异常可致人与动物软骨发育异常和关节软骨退行性改变。为进一步明确大骨节病软骨细胞终末分化障碍的潜在机制及其与可疑病因关系，本研究主要内容包括：1)确定大骨节病软骨组织及细胞PTHrP-HDAC4信号通路相关基因及蛋白表达特征；2)确定PTHrP-HDAC4信号通路在大骨节病软骨细胞终末分化障碍中的作用及调控机制；3)确定T-2毒素及HT-2毒素和/或低硒通过PTHrP-HDAC4信号通路致大骨节病软骨细胞终末分化障碍的作用。本研究预期结果将揭示PTHrP-HDAC4信号通路在大骨节病软骨细胞终末分化障碍中的作用机制及其与环境危险因素的病因关系，为进一步推进大骨节病的病因发病机制研究和寻找潜在干预靶点提供理论和实验依据。

大骨节病软骨组织损伤涉及软骨细胞分化障碍，大量研究证实PthrP-HDAC4信号通路在软骨细胞成熟分化中具有重要作用，但其是否参与大骨节病软骨细胞分化障碍及其与环境危险因素的关系尚缺乏深入研究。本项目首先通过免疫组化观察了PthrP、HDAC4在大骨节病软骨组织中的表达情况，并通过细胞毒性和基因表达分析比较了T-2毒素、DON诱导软骨细胞的差异表达基因及其与大骨节病的关系，然后通过体内外实验探讨了T-2毒素干预对软骨细胞和实验动物软骨组织PthrP-HDAC4信号通路的影响。项目主要结果包括：①证实了PthrP、HDAC4在儿童和成人大骨节病软骨组织中表达不同于正常对照，提示该信号通路参与大骨节病软骨细胞终末分化障碍；②T-2毒素和DON干预人软骨细胞表现出不同的毒性特征，二者干预人软骨细胞的差异表达基因FABP4、FBLN1、RGS5、GDF5等在大骨节病发病中有重要作用，可作为大骨节病病因机制的潜在分子标志物；③T-2毒素干预可导致人软骨细胞系PthrP、HDAC4、RUNX2、COL10A1、MEF2C等基因和蛋白表达升高，且T-2毒素和/或低硒喂养大鼠可导致大鼠生长板软骨细胞HDAC4、MEF2C表达降低，说明T-2毒素等环境危险因素可通过HDAC4信号通路影响软骨细胞终末分化；④大骨节病患者胫骨平台内侧软骨下骨硬化和厚度较外侧显著增加，且证实ADAMTS14、SLC13A5等基因在大骨节病与骨关节炎软骨下骨中差异表达，提示其可作为两种疾病鉴别诊断的分子标志物。本项目完成为进一步明确大骨节病软骨发育障碍的分子机制，以及大骨节病与骨性关节炎的鉴别诊断提供了新的实验和理论依据。在本项目资助下，已发表SCI和中文核心论文5篇。