Prakash Jai, Sandovici Maria, Saluja Vinay, Lacombe Marie, Schaapveld Roel Q J, de Borst Martin H, van Goor Harry, Henning Robert H, Proost Johannes H, Moolenaar Frits, Këri György, Meijer Dirk K F, Poelstra Klaas, Kok Robbert J
Department of Pharmaceutics, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht, The Netherlands.
J Pharmacol Exp Ther. 2006 Oct;319(1):8-19. doi: 10.1124/jpet.106.106054. Epub 2006 Jun 28.
During renal injury, activation of p38 mitogen-activated protein kinase (MAPK) in proximal tubular cells plays an important role in the inflammatory events that eventually lead to renal fibrosis. We hypothesized that local inhibition of p38 within these cells may be an interesting approach for the treatment of renal fibrosis. To effectuate this, we developed a renal-specific conjugate of the p38 inhibitor SB202190 [4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)1H-imidazole] and the carrier lysozyme. First, we demonstrated that SB202190 inhibited the expression of albumin-induced proinflammatory (monocyte chemoattractant protein-1) and transforming growth factor (TGF)-beta1-induced profibrotic (procollagen-Ialpha1) genes over 50% in renal tubular cells (normal rat kidney-52E). Next, we conjugated SB202190 via a carbamate linkage to lysozyme. However, this conjugate rapidly released the drug upon incubation in serum. Therefore, we applied a new platinum(II)-based linker approach, the so-called universal linkage system (ULS), which forms a coordinative bond with SB202190. The SB202190-ULS-lysozyme remained stable in serum but released the drug in kidney homogenates. SB202190-ULS-lysozyme accumulated efficiently in renal tubular cells and provided a local drug reservoir during a period of 3 days after a single intravenous injection. Treatment with SB202190-ULS-lysozyme inhibited TGF-beta1-induced gene expression for procollagen-Ialpha1 by 64% in HK-2 cells. Lastly, we evaluated the efficacy of a single dose of the conjugate in the unilateral renal ischemia-reperfusion rat model. A reduction of intrarenal p38 phosphorylation and alpha-smooth muscle actin protein expression was observed 4 days after the ischemia-reperfusion injury. In conclusion, we have developed a novel strategy for local delivery of the p38 MAPK inhibitor SB202190, which may be of use in the treatment of renal fibrosis.
在肾损伤期间，近端肾小管细胞中p38丝裂原活化蛋白激酶（MAPK）的激活在最终导致肾纤维化的炎症事件中起重要作用。我们推测在这些细胞内局部抑制p38可能是治疗肾纤维化的一种有趣方法。为实现这一点，我们开发了p38抑制剂SB202190 [4-(4-氟苯基)-2-(4-羟基苯基)-5-(4-吡啶基)1H-咪唑]与载体溶菌酶的肾特异性缀合物。首先，我们证明SB202190在肾小管细胞（正常大鼠肾-52E）中抑制白蛋白诱导的促炎（单核细胞趋化蛋白-1）和转化生长因子（TGF）-β1诱导的促纤维化（I型前胶原α1）基因的表达超过50%。接下来，我们通过氨基甲酸酯键将SB202190与溶菌酶缀合。然而，该缀合物在血清中孵育时会迅速释放药物。因此，我们应用了一种新的基于铂（II）的连接方法，即所谓的通用连接系统（ULS），它与SB202190形成配位键。SB202190-ULS-溶菌酶在血清中保持稳定，但在肾匀浆中释放药物。SB202190-ULS-溶菌酶在单次静脉注射后3天内有效地在肾小管细胞中积累并提供局部药物储存库。用SB202190-ULS-溶菌酶处理在HK-2细胞中抑制TGF-β1诱导的I型前胶原α1基因表达64%。最后，我们在单侧肾缺血再灌注大鼠模型中评估了单剂量缀合物的疗效。在缺血再灌注损伤后4天观察到肾内p38磷酸化和α-平滑肌肌动蛋白蛋白表达降低。总之，我们开发了一种局部递送p38 MAPK抑制剂SB202190的新策略，其可能用于治疗肾纤维化。
