慢性肾脏病(CKD)的主要特征包括肾小管间质炎症和纤维化。蛋白酶激活受体2(PAR2),由肾脏近端肾小管细胞表达的G蛋白偶联受体(GPCR),在这些细胞中诱导有效的促炎反应。这里测试的假设是PAR2信号传导可以通过反式激活已知的疾病相关途径来促进肾脏中的炎症和纤维化。使用人肾小管上皮细胞(HTEC)的原代细胞培养模型,PAR2激活诱导浓度依赖性,PAR2拮抗剂敏感,分泌TNF,CSF2、MMP-9、PAI-1和CTGF。PAR2激动剂2F激活的转录因子,包括NFκB,AP1和Smad2对于这些细胞因子的产生至关重要。TGF-β受体-1(TGF-βRI)激酶抑制剂,SB431542和EGFR激酶抑制剂,AG1478,改善2F诱导的TNF分泌,CSF2、MMP-9和PAI-1。虽然EGFR阻断抗体,西妥昔单抗,阻断PAR2诱导EGFR和ERK磷酸化,TGF-βRII阻断抗体未能影响PAR2诱导的PAI-1分泌。值得注意的是同时激活TGF-βRII(TGF-β1)和PAR2(2F)协同增强TNF的分泌(2.2倍),CSF2(4.4倍),MMP-9(15倍),和PAI-1(2.5倍)。总之,PAR2激活人肾小管上皮细胞中的关键炎症和纤维化信号传导途径。应探索PAR2的偏置拮抗剂作为CKD的潜在疗法。
Key features of chronic kidney disease (CKD) include tubulointerstitial inflammation and fibrosis. Protease activated receptor-2 (
PAR2), a G-protein coupled receptor (GPCR) expressed by the kidney proximal tubular cells, induces potent proinflammatory responses in these cells. The hypothesis tested here was that
PAR2 signalling can contribute to both inflammation and fibrosis in the kidney by transactivating known disease associated pathways. Using a primary cell culture model of human kidney tubular epithelial cells (HTEC), PAR2 activation induced a concentration dependent,
PAR2 antagonist sensitive, secretion of TNF, CSF2, MMP-9, PAI-1 and CTGF. Transcription factors activated by the PAR2 agonist 2F, including NFκB, AP1 and Smad2, were critical for production of these cytokines. A TGF-β receptor-1 (TGF-βRI) kinase inhibitor, SB431542, and an EGFR kinase inhibitor, AG1478, ameliorated 2F induced secretion of TNF, CSF2, MMP-9, and PAI-1. Whilst an EGFR blocking antibody, cetuximab, blocked PAR2 induced EGFR and ERK phosphorylation, a TGF-βRII blocking antibody failed to influence
PAR2 induced secretion of PAI-1. Notably simultaneous activation of TGF-βRII (TGF-β1) and PAR2 (2F) synergistically enhanced secretion of TNF (2.2-fold), CSF2 (4.4-fold), MMP-9 (15-fold), and PAI-1 (2.5-fold). In summary PAR2 activates critical inflammatory and fibrotic signalling pathways in human kidney tubular epithelial cells. Biased antagonists of
PAR2 should be explored as a potential therapy for CKD.