Fretz Marjan M, Dolman M E Emmy M, Lacombe Marie, Prakash Jai, Nguyen Tri Q, Goldschmeding Roel, Pato Janos, Storm Gert, Hennink Wim E, Kok Robbert J
Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands.
J Control Release. 2008 Dec 18;132(3):200-7. doi: 10.1016/j.jconrel.2008.08.013. Epub 2008 Aug 27.
Cell-specific targeting to renal tubular cells is an interesting approach to enhance the accumulation of drugs in the kidney. Low molecular weight proteins are rapidly filtered and extensively accumulate in proximal tubular cells. We therefore have used lysozyme (LZM, 14 kDa) as a tubular cell-specific carrier for the delivery of kinase inhibitors. Two different kinase inhibitors (LY364947 and erlotinib, directed to either the TGF-beta receptor kinase or the EGF receptor) were individually conjugated to LZM via a novel platinum-based linker (Universal Linkage System; ULS). The cellular handling and pharmacological efficacy of the conjugates were evaluated in cultured proximal tubular cells (HK-2 cells). Both conjugates were efficiently internalized via endocytosis. TGF-beta or EGF activated HK-2 cells showed a strong activation of the studied kinases and the conjugates inhibited these events, as was demonstrated by Western blotting of phosphorylated downstream mediators and quantitative gene expression analysis. In conclusion, we have developed tubular cell-specific kinase inhibitor-LZM conjugates via a novel linker strategy, which both showed to be effective in vitro. Future in vivo studies should show their potential for the treatment of renal diseases.
细胞特异性靶向肾小管细胞是一种增强药物在肾脏中蓄积的有趣方法。低分子量蛋白质会被快速滤过并大量蓄积在近端肾小管细胞中。因此，我们使用溶菌酶（LZM，14 kDa）作为肾小管细胞特异性载体来递送激酶抑制剂。两种不同的激酶抑制剂（LY364947和厄洛替尼，分别作用于转化生长因子-β受体激酶或表皮生长因子受体）通过一种新型铂基连接体（通用连接系统；ULS）分别与LZM偶联。在培养的近端肾小管细胞（HK-2细胞）中评估了偶联物的细胞处理过程和药理功效。两种偶联物均通过内吞作用有效地被内化。转化生长因子-β或表皮生长因子激活的HK-2细胞显示出所研究激酶的强烈激活，而偶联物抑制了这些事件，这通过磷酸化下游介质的蛋白质印迹和定量基因表达分析得以证明。总之，我们通过一种新型连接体策略开发了肾小管细胞特异性激酶抑制剂-LZM偶联物，二者在体外均显示出有效性。未来的体内研究应揭示它们在治疗肾脏疾病方面的潜力。
