Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Key Laboratory of Rheumatology and Clinical Immunology, Ministry of Education, Beijing, China.
Ann Rheum Dis. 2020 Apr;79(4):518-524. doi: 10.1136/annrheumdis-2019-216428. Epub 2020 Feb 29.
Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterised by aberrant B cell hyperactivation, whose mechanism is partially understood.
We performed whole transcriptome sequencing of B cells from three pSS patients and three matched healthy controls (HC). Differentially expression genes (DEGs) were confirmed with B cells from 40 pSS patients and 40 HC by quantitative PCR and western blot. We measured the proliferation potential and immunoglobulins production of siRNA-transfected or plasmid-transfected B cells stimulated with cytosine-phosphate-guanine (CpG) or anti-IgM. We also explored Toll-like receptor 9 (TLR9) signalling to reveal the potential mechanism of B cell hyperactivation in pSS.
We identified 77 upregulated and 32 downregulated DEGs in pSS B cells. We confirmed that epithelial stromal interaction (EPST1) expression in pSS B cells was significantly higher than that from HCs. EPSTI1-silencing B cells stimulated with CpG were less proliferated and produced lower level of IgG and IgM comparing with control B cells. EPSTI1-silencing B cells expressed lower level of p-p65 and higher level of IκBα, and B cells with overexpressed EPSTI1 showed higher level of p-p65 and lower level of IκBα. Finally, IκBα degradation inhibitor Dehydrocostus Lactone treatment attenuated p65 phosphorylation promoted by EPSTI1.
Elevated EPSTI1 expression in pSS B cells promoted TLR9 signalling activation and contributed to the abnormal B cell activation, which was promoted by facilitating p65 phosphorylation and activation of NF-κB signalling via promoting IκBα degradation. EPSTI1 might be implicated in pSS pathogenesis and was a potential therapeutic target of pSS.
原发性干燥综合征（pSS）是一种以 B 细胞异常激活为特征的系统性自身免疫性疾病，其机制部分得到了解。
我们对 3 例 pSS 患者和 3 例匹配的健康对照（HC）的 B 细胞进行了全转录组测序。通过定量 PCR 和 Western blot 对 40 例 pSS 患者和 40 例 HC 的 B 细胞进行了差异表达基因（DEG）的验证。我们测量了经 siRNA 或质粒转染的 B 细胞在细胞嘧啶磷酸鸟嘌呤（CpG）或抗 IgM 刺激下的增殖潜力和免疫球蛋白产生。我们还探索了 Toll 样受体 9（TLR9）信号转导，以揭示 pSS 中 B 细胞过度激活的潜在机制。
我们在 pSS B 细胞中鉴定出 77 个上调和 32 个下调的 DEG。我们证实 pSS B 细胞中的上皮基质相互作用（EPST1）表达明显高于 HC。与对照 B 细胞相比，CpG 刺激的 EPSTI1 沉默 B 细胞增殖能力较低，IgG 和 IgM 产生水平较低。EPSTI1 沉默 B 细胞表达较低的 p-p65 和较高的 IκBα，而过表达 EPSTI1 的 B 细胞则表现出较高的 p-p65 和较低的 IκBα。最后，IκBα 降解抑制剂脱氢柯诺辛内酯处理可减弱 EPSTI1 促进的 p65 磷酸化。
pSS B 细胞中 EPSTI1 的表达升高促进了 TLR9 信号通路的激活，并导致异常的 B 细胞激活，这是通过促进 IκBα 降解来促进 p65 磷酸化和 NF-κB 信号通路的激活而促进的。EPSTI1 可能与 pSS 的发病机制有关，是 pSS 的潜在治疗靶点。
