Department of Pediatrics, Hirosaki University Hospital, Hirosaki, Aomori, Japan.
Department of Vascular Biology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan.
Ren Fail. 2023 Dec;45(1):2224890. doi: 10.1080/0886022X.2023.2224890.
In addition to regulating the antiviral response, increased expression of Toll-like receptor 3 (TLR3) in resident renal cells plays a role in developing some forms of glomerulonephritis. TLR3 activation leads to type I interferon (IFN) production, which induces the expression of IFN-stimulated genes (ISGs). However, the role of ISG20 expression in resident renal cells remains unclear.
Cultured normal human glomerular endothelial cells (GECs) were treated with polyinosinic-polycytidylic acid (poly IC), lipopolysaccharide (LPS), R848, and CpG (TLR3, TLR4, TLR7, and TLR9 agonists, respectively). The mRNA levels of ISG20, CX3CL1/fractalkine, and CXCL10/IP-10 were measured by quantitative reverse transcription-polymerase chain reaction. ISG20 protein expression was assessed by Western blotting. RNA interference was used to knockdown IFN-β and ISG20 expression. CX3CL1 protein levels were assessed by enzyme-linked immunosorbent assay. We performed immunofluorescence to examine endothelial ISG20 expression in biopsy specimens from patients with lupus nephritis (LN).
In GECs, the expression of ISG20 mRNA and protein was increased by polyIC, not by LPS, R848, or CpG treatment. Moreover, ISG20 knockdown prevented poly IC-induced CX3CL1 expression but had no effect on CXCL10 expression. Intense endothelial ISG20 immunoreactivity was observed in biopsy specimens obtained from patients with proliferative LN.
In GECs, ISG20 was regulated TLR3 but not TLR4, TLR7, or TLR9 signaling. Moreover, ISG20 was involved in regulating CX3CL1 production. In addition to regulating antiviral innate immunity, ISG20 may act as a mediator of CX3CL1 production, thereby inducing glomerular inflammation, particularly in patients with LN.
除了调节抗病毒反应外，驻留肾细胞中 Toll 样受体 3（TLR3）的表达增加在某些形式的肾小球肾炎的发展中也起着作用。TLR3 激活导致 I 型干扰素（IFN）的产生，从而诱导 IFN 刺激基因（ISG）的表达。然而，驻留肾细胞中 ISG20 的表达的作用尚不清楚。
用多聚肌苷酸-多聚胞苷酸（poly IC）、脂多糖（LPS）、R848 和 CpG（TLR3、TLR4、TLR7 和 TLR9 的激动剂）处理培养的正常人肾小球内皮细胞（GEC）。通过定量逆转录聚合酶链反应测量 ISG20、CX3CL1/fractalkine 和 CXCL10/IP-10 的 mRNA 水平。通过 Western 印迹评估 ISG20 蛋白表达。使用 RNA 干扰敲低 IFN-β 和 ISG20 的表达。通过酶联免疫吸附试验评估 CX3CL1 蛋白水平。我们进行免疫荧光检查以检查狼疮肾炎（LN）患者活检标本中的内皮细胞 ISG20 表达。
在 GEC 中，polyIC 可增加 ISG20 mRNA 和蛋白的表达，而 LPS、R848 或 CpG 处理则不能。此外，ISG20 敲低可阻止 poly IC 诱导的 CX3CL1 表达，但对 CXCL10 表达没有影响。在增生性 LN 患者的活检标本中观察到强烈的内皮细胞 ISG20 免疫反应性。
在 GEC 中，ISG20 受 TLR3 调节，但不受 TLR4、TLR7 或 TLR9 信号调节。此外，ISG20 参与调节 CX3CL1 的产生。除了调节抗病毒先天免疫外，ISG20 可能作为 CX3CL1 产生的介质，从而诱导肾小球炎症，特别是在 LN 患者中。
