ZBTB33介导IL-17/WNT通路参与强直性脊柱炎病理性骨化的作用机制

Ankylosing spondylitis (AS) is difficult to diagnose in early stage, and can cause long-term disability in late stage. The chronic inflammation induced by IL-17 and other cytokines, and ligament ossification mediated by WNT pathway may be the basis molecular pathology of the disease. However, the intermediate mechanism about how inflammation causes ossification is not clear. We have found that ZBTB33 and its antibody were uniformly elevated in the ligament and serum of AS patients. We further found that ZBTB33 is not only involved in the regulation of WNT signaling, but also interacts with the IL-17Ra, suggesting that ZBTB33 plays an important role in the mechanism of inflammation to ossification process. Based on this hypothesis, we plan to carry out the following studies: (1) Detecting the level and biological effect of ZBTB33 antibody in AS serum. (2) Constructing the fibroblast cell line with ZBTB33 knockdown and overexpression, and exploring the regulation mechanism of ZBTB33 to IL-17/Wnt pathway. (3) exploring the IL-17/Wnt pathway downstream activation sites based on the RNA-seq technology. (4) Evaluating the effect of ZBTB33-siRNA in spondyloarthritis mouse model. After the study, we will not only provide a serological marker for early diagnosis, but also accumulate theoretical basis for AS targeted therapy.

强直性脊柱炎（AS）是一种早期不易诊断，而晚期致残率高的疾病。IL-17等细胞因子促发的慢性炎症和WNT通路介导的韧带骨化可能是该病的主要分子病理基础，但炎症导致骨化的中间机制不清楚。申请人发现ZBTB33及其自身抗体在AS患者韧带及血清中一致升高；进一步发现ZBTB33不仅参与调节WNT信号，而且与IL-17Ra存在相互作用，提示ZBTB33在AS的炎症致骨化机制中有重要作用。围绕该假设，本课题将展开：①检测AS血清ZBTB33抗体水平及生物学效应；②构建ZBTB33敲减/过表达AS成纤维细胞系，探索ZBTB33对IL-17/WNT通路的调节机制；③基于RNA-seq 技术，探索IL-17/WNT通路下游活化位点；④采用ZBTB33-siRNA干预脊柱关节小鼠模型，评估疗效。课题完成后，不仅为AS早期诊断提供血清学标志物，而且为AS的靶向治疗积累理论依据。

背景：强直性脊柱炎（ankylosing spondylitis，AS）是一种慢性炎症性自身免疫性疾病。疾病特征包括起止点炎、渐进发展的骶髂关节炎以及脊柱关节强直。由于缺乏典型的早期症状和明确的早期生物标记物，AS通常在第一次临床症状出现后的8-10年时间才能得到明确的诊断。近年来越来越多的证据表明B细胞和相应的体液免疫反应可能通过抗原提呈，抗体产生等方式参与AS的发病过程。.研究内容：筛选强直性脊柱炎患者血浆内的自身抗体并扩大样本验证ZBTB33蛋白自身抗体在强直性脊柱炎血浆内的表达情况；探究ZBTB33分子在体内外实验中对成骨分化进程的影响；探索ZBTB33分子调节成骨分化进程的具体机制。.重要结果：早期AS患者体内ZBTB33抗体表达水平显著高于正常人，晚期AS患者血浆内表达水平与正常人无显著差异。细胞及动物实验揭示ZBTB33可显著抑制成骨分化进程，进一步机制探究显示ZBTB33分子可通过结合Itga10来调控PI3K-Akt 信号通路从而抑制成骨分化过程。.科学意义：本课题试图通过蛋白芯片在AS血液样本中筛选到合适的可以作为AS早期诊断的标志物,并研究自身抗体相应的抗原蛋白在疾病发生发展中的作用及机制,从而为强直性脊柱炎寻找合适的标志物及可能的治疗靶点。