Previously, we reported that serum Semaphorin 5 A (Sema5A) levels were increased in systemic lupus erythematosus (SLE) patients compared with healthy controls (HC), and elevated Sema5A correlated with disease activity and lupus nephritis in SLE patients. In this study, we aimed to further understand the role of Sema5A in promoting Th17 cells differentiation in SLE. Sema5A, interferon gamma (IFN-γ), interleukin 4 (IL-4), interleukin 17 A (IL-17 A) and interleukin 10 (IL-10) were measured by Enzyme Linked Immunosorbent Assay (ELISA). RNA and protein were isolated from peripheral blood mononuclear cells (PBMCs) in SLE patients and HC. Expression of PlexinA1 and PlexinB3 were measured by quantitative RT-PCR (qRT-PCR) and Western Blot. Th cell subsets were detected by flow cytometry. Treatment with recombinant human Sema5A (rhSema5A) and small interfering RNA (siRNA) were employed to examine the in vitro effect of Sema5A in CD4+T cell differentiation in SLE patients. IL-17 A elevated in SLE patients and positively correlated with Sema5A. PlexinA1 was upregulated and mainly expressed in CD4+ T cells of SLE; Sema5A treatment induced the differentiation of Th17 cells, while did not affect the Th1 and Th2 skewing. These effects were associated with an upregulation of the transcription factor RORγt by Th17 cells, but not T-bet or GATA3 in Th1 and Th2 cells, respectively. Knock down PlexinA1 regulates IL-17 A production by CD4+T cells. Functional assays showed that Sema5A-PlexinA1 axis promoted Th17 cells differentiation via PI3K/Akt/mTOR signaling. These findings demonstrated that Sema5A-PlexinA1 axis acts as a key mediator on Th17 differentiation, suggesting that Sema5A might be a novel therapeutic target in SLE.

中文翻译：

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信号素 5A 在系统性红斑狼疮中通过 PI3K-Akt-mTOR 促进 Th17 分化


以前，我们报道了与健康对照 （HC） 相比，系统性红斑狼疮 （SLE） 患者的血清信号素 5 A （Sema5A） 水平升高，并且 Sema5A 升高与 SLE 患者的疾病活动和狼疮肾炎相关。在这项研究中，我们旨在进一步了解 Sema5A 在促进 SLE 中 Th17 细胞分化中的作用。通过酶联免疫吸附测定 （ELISA） 测量 Sema5A 、干扰素 γ （IFN-γ ）、白细胞介素 4 （IL-4） 、白细胞介素 17 A （IL-17 A） 和白细胞介素 10 （IL-10）。从 SLE 患者和 HC 的外周血单核细胞 （PBMC） 中分离 RNA 和蛋白质。通过定量 RT-PCR （qRT-PCR） 和 Western Blot 检测 PlexinA1 和 PlexinB3 的表达。流式细胞术检测 Th 细胞亚群。采用重组人 Sema5A （rhSema5A） 和小干扰 RNA （siRNA） 治疗，检测 Sema5A 在 SLE 患者 CD4+T 细胞分化中的体外作用。SLE 患者的 IL-17 A 升高，与 Sema5A 呈正相关。PlexinA1 上调，主要在 SLE 的 CD4+ T 细胞中表达;Sema5A 处理诱导 Th17 细胞分化，而不影响 Th1 和 Th2 偏斜。这些作用与 Th17 细胞转录因子 RORγt 的上调有关，但与 Th1 和 Th2 细胞中的 T-bet 或 GATA3 分别无关。敲低 PlexinA1 调节 CD4+T 细胞产生 IL-17 A。功能测定显示 Sema5A-PlexinA1 轴通过 PI3K/Akt/mTOR 信号传导促进 Th17 细胞分化。这些发现表明 Sema5A-PlexinA1 轴是 Th17 分化的关键介质，表明 Sema5A 可能是 SLE 的新治疗靶点。