Department of Nephrology, Huashan Hospital, Fudan University, Shanghai, China.
Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.
Int Immunopharmacol. 2018 Dec;65:422-428. doi: 10.1016/j.intimp.2018.10.038. Epub 2018 Oct 30.
Tacrolimus is considered to be one of the main therapeutic options for idiopathic membranous nephropathy (IMN). This study aimed to investigate the association of variants in genes encoding the binding protein and the drug target (calcineurin) of tacrolimus with the efficacy in IMN patients and the potential mechanism. Sixty-seven IMN patients treated with tacrolimus were enrolled retrospectively. Sanger sequencing was performed to search for variants in all exons of the genes in 8 IMN patients and genotype for the detected variants in the other 59 patients. The molecular mechanism underlying the relationship between the variants and the efficacy was explored in human peripheral blood mononuclear cells (PBMCs) and other cell lines. Single nucleotide polymorphism rs875 (T > C) in the 3'untranslated region (3'UTR) of PPP3R1 encoding calcineurin regulatory subunit was found to be associated with the treatment efficacy of tacrolimus for IMN. Patients carrying TT genotype had a significantly higher remission rate than those carrying TC/CC genotype (83% vs. 47%, P = 0.008). Western blot showed that the TT genotype carriers exhibited reduced PPP3R1 protein levels in PBMCs (P = 0.02). Compared with C allele, T allele displayed increased binding affinity for miR-582-5p in the luciferase reporter assay (P < 0.001). Moreover, knockdown of PPP3R1 in Jurkat T cell line enhanced the immunosuppressive effect of tacrolimus. Our study revealed the association of PPP3R1 3'UTR polymorphism rs875 with the efficacy of tacrolimus in IMN patients. The functional polymorphism might alter PPP3R1 expression via modulating the interaction of miR-582-5p with PPP3R1, which further affected the immunosuppressive effect of tacrolimus.
他克莫司被认为是特发性膜性肾病（IMN）的主要治疗选择之一。本研究旨在探讨他克莫司结合蛋白和药物靶点（钙调神经磷酸酶）编码基因的变异与 IMN 患者疗效的相关性及其潜在机制。回顾性纳入 67 例接受他克莫司治疗的 IMN 患者。对 8 例 IMN 患者的所有外显子进行 Sanger 测序以寻找基因变异，对其余 59 例患者进行检测到的变异的基因分型。在人外周血单个核细胞（PBMC）和其他细胞系中探讨了变异与疗效之间关系的分子机制。发现 PPP3R1 编码钙调神经磷酸酶调节亚基的 3'非翻译区（3'UTR）中的单核苷酸多态性 rs875（T > C）与他克莫司治疗 IMN 的疗效相关。携带 TT 基因型的患者缓解率明显高于 TC/CC 基因型患者（83% vs. 47%，P = 0.008）。Western blot 显示 TT 基因型携带者的 PBMC 中 PPP3R1 蛋白水平降低（P = 0.02）。与 C 等位基因相比，T 等位基因在荧光素酶报告基因检测中显示出对 miR-582-5p 的结合亲和力增加（P < 0.001）。此外，在 Jurkat T 细胞系中敲低 PPP3R1 增强了他克莫司的免疫抑制作用。本研究揭示了 PPP3R1 3'UTR 多态性 rs875 与 IMN 患者他克莫司疗效的相关性。功能性多态性可能通过调节 miR-582-5p 与 PPP3R1 的相互作用改变 PPP3R1 表达，进而影响他克莫司的免疫抑制作用。
