Combining single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics, we sequenced six matched synovial tissue samples from three patients with relapse RA and three patients in remission. We analyzed the differences in the transcriptomes of the FLS subsets between the relapse and remitted phases. We validated several key signaling pathways using quantitative real-time PCR (qPCR) and multiplex immunohistochemistry (mIHC). We further targeted the critical signals in vitro and in vivo using the collagen-induced arthritis (CIA) model in rats.
Lining and sublining FLS subsets were identified using scRNA-seq. Differential analyses indicated that the fibroblast growth factor (FGF) pathway was highly activated in the lining FLSs from patients with relapse RA for which mIHC confirmed the increased expression of FGF10. Although the type I interferon pathway was also activated in the lining FLSs, in vitro stimulation experiment suggested that it was independent of the FGF10 pathway. FGF10 knockdown by small interfering RNA in FLSs significantly reduced the expression of receptor activator of NF-κB ligand. Moreover, recombinant FGF10 protein enhanced bone erosion in the primary human-derived pannus cell culture, whereas the FGF receptor (FGFR) 1 inhibitor attenuated this process. Finally, administering an FGFR1 inhibitor displayed a therapeutic effect in a CIA rat model.
The FGF pathway is a critical signaling pathway in relapse RA. Targeted tissue-specific inhibition of FGF10/FGFR1 may provide new opportunities to treat patients with relapse RA.
方法:结合单细胞RNA测序(scRNA-seq)和空间转录组学,我们对3例RA复发患者和3例缓解患者的6份匹配滑膜组织样本进行了测序.我们分析了复发和缓解期之间FLS亚群转录组的差异。我们使用qPCR和多重免疫组织化学(HC)验证了几个关键的信号通路。我们使用大鼠的拼贴诱导的关节炎(CIA)模型在体外和体内进一步靶向了关键信号。
结果:使用scRNA-seq鉴定了Lining和subliningFLS亚群。差异分析表明,成纤维细胞生长因子(FGF)途径在复发RA患者的衬里FLS中高度激活,其中mIHC证实FGF10的表达增加。虽然在衬里FLS中I型干扰素途径也被激活,体外刺激实验表明它与FGF10途径无关。FLS中通过siRNA敲除FGF10显著降低RANKL的表达。此外,重组FGF10蛋白增强了原代人源性血管内细胞培养物中的骨侵蚀,而FGFR1抑制剂减弱了这一过程。最后,施用FGFR1抑制剂在aCIA大鼠模型中显示出治疗效果。
结论:FGF通路是RA复发的关键信号通路。FGF10/FGFR1的靶向组织特异性抑制可能为治疗RA复发患者提供新的机会。