Yuan Yi, Zhao Ling, Ma Ning, Ye Zhuang, Jiang Zhenyu, Chu Congqiu
Department of Rheumatology and Immunology, Jilin University, Changchun, China.
Department of Arthritis and Rheumatic Diseases, Oregon Health & Science University and Va Portland Health Care System, Oregon, USA.
Arch Rheumatol. 2017 Apr 17;32(4):275-283. doi: 10.5606/ArchRheumatol.2017.6279. eCollection 2017 Dec.
This study aims to assess the complement 3 (C3) expressions in whole blood cells and verify a pathway toll-like receptor 9 (TLR9)/ transforming growth factor-beta 1 (TGF-β1)/C3 for C3 regulation in mediating thrombocytopenia (TCP) in patients with systemic lupus erythematosus (SLE).
The study included 63 newly diagnosed SLE patients (2 males, 61 females; mean age 39.5 years; range 15 to 67 years). Whole blood messenger ribonucleic acid expression for C3, TLR9 and TGF-β1 were measured by quantitative reverse transcription real-time polymerase chain reaction in SLE patients with TCP (n=38) and age- and sex-matched SLE patients without TCP (n=25) at baseline and in 10 SLE patients with TCP after four weeks of treatment. Whole blood cells from SLE patients with TCP were cultured in the presence of TLR9 ligand cytosine-phosphate- guanine, recombinant human TGF-β1, TGF-β receptor inhibitor/activin receptor-like kinase inhibitor SB431542. TGF-β1 and C3 levels in whole blood cells cultures were determined by quantitative reverse transcription real-time polymerase chain reaction and enzyme-linked immunosorbent assay.
Whole blood cells from SLE patients with TCP displayed an enhanced gene expression for C3, TLR9 and TGF-β1 compared with that of SLE patients without TCP (p<0.01 for C3, p<0.05 for TLR9 and TGF-β1). SLE patients with TCP had decreased plasma levels of C3 suggesting excessive consumption. In whole blood cell culture, engagement of TLR9 led to the increased gene expression of C3. Furthermore, TGF-β1 inhibitor abolished TLR9 stimulation on C3 gene expression.
These results suggest that blood cells are the source of extra-hepatic synthesis of C3 in SLE patients with TCP and this synthesis of C3 was up-regulated by TLR9 via induction of TGF-β1. Thus TLR9/TGF-β1/C3 pathway might be in operation mediating lupus thrombocytopenia.
本研究旨在评估全血细胞中补体3（C3）的表达，并验证Toll样受体9（TLR9）/转化生长因子-β1（TGF-β1）/C3通路在系统性红斑狼疮（SLE）患者介导血小板减少症（TCP）过程中对C3的调节作用。
本研究纳入63例新诊断的SLE患者（2例男性，61例女性；平均年龄39.5岁；范围15至67岁）。通过定量逆转录实时聚合酶链反应，在基线时检测38例合并TCP的SLE患者以及25例年龄和性别匹配的未合并TCP的SLE患者全血中C3、TLR9和TGF-β1的信使核糖核酸表达，并在10例合并TCP的SLE患者治疗4周后进行检测。将合并TCP的SLE患者的全血细胞在TLR9配体胞嘧啶-磷酸-鸟嘌呤、重组人TGF-β1、TGF-β受体抑制剂/激活素受体样激酶抑制剂SB431542存在的情况下进行培养。通过定量逆转录实时聚合酶链反应和酶联免疫吸附测定法测定全血细胞培养物中的TGF-β1和C3水平。
与未合并TCP的SLE患者相比，合并TCP的SLE患者全血细胞中C3、TLR9和TGF-β1的基因表达增强（C3 p<0.01，TLR9和TGF-β1 p<0.05）。合并TCP的SLE患者血浆C3水平降低，提示消耗过多。在全血细胞培养中，TLR9的激活导致C3基因表达增加。此外，TGF-β1抑制剂消除了TLR9对C3基因表达的刺激作用。
这些结果表明，血细胞是合并TCP的SLE患者肝外合成C3的来源，且TLR9通过诱导TGF-β1上调了C3的合成。因此，TLR9/TGF-β1/C3通路可能在介导狼疮性血小板减少症中起作用。
