Wong Chun-Ho, Nguyen Lien, Peh Jessie, Luu Long M, Sanchez Jeannette S, Richardson Stacie L, Tuccinardi Tiziano, Tsoi Ho, Chan Wood Yee, Chan H Y Edwin, Baranger Anne M, Hergenrother Paul J, Zimmerman Steven C
Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States.
J Am Chem Soc. 2014 Apr 30;136(17):6355-61. doi: 10.1021/ja5012146. Epub 2014 Apr 22.
A working hypothesis for the pathogenesis of myotonic dystrophy type 1 (DM1) involves the aberrant sequestration of an alternative splicing regulator, MBNL1, by expanded CUG repeats, r(CUG)(exp). It has been suggested that a reversal of the myotonia and potentially other symptoms of the DM1 disease can be achieved by inhibiting the toxic MBNL1-r(CUG)(exp) interaction. Using rational design, we discovered an RNA-groove binding inhibitor (ligand 3) that contains two triaminotriazine units connected by a bisamidinium linker. Ligand 3 binds r(CUG)12 with a low micromolar affinity (K(d) = 8 ± 2 μM) and disrupts the MBNL1-r(CUG)12 interaction in vitro (K(i) = 8 ± 2 μM). In addition, ligand 3 is cell and nucleus permeable, exhibits negligible toxicity to mammalian cells, dissolves MBNL1-r(CUG)(exp) ribonuclear foci, and restores misregulated splicing of IR and cTNT in a DM1 cell culture model. Importantly, suppression of r(CUG)(exp) RNA-induced toxicity in a DM1 Drosophila model was observed after treatment with ligand 3. These results suggest ligand 3 as a lead for the treatment of DM1.
1型强直性肌营养不良症（DM1）发病机制的一个有效假设涉及到一种可变剪接调节因子MBNL1被扩增的CUG重复序列r(CUG)(exp)异常隔离。有人提出，通过抑制有毒的MBNL1-r(CUG)(exp)相互作用，可以实现DM1疾病肌强直及其他潜在症状的逆转。通过合理设计，我们发现了一种RNA-凹槽结合抑制剂（配体3），它含有两个由双脒基连接子连接的三氨基三嗪单元。配体3以低微摩尔亲和力（K(d)=8±2μM）结合r(CUG)12，并在体外破坏MBNL1-r(CUG)12相互作用（K(i)=8±2μM）。此外，配体3具有细胞和细胞核通透性，对哺乳动物细胞的毒性可忽略不计，能溶解MBNL1-r(CUG)(exp)核糖核蛋白病灶，并在DM1细胞培养模型中恢复IR和cTNT的异常剪接。重要的是，在用配体3处理后，在DM1果蝇模型中观察到r(CUG)(exp)RNA诱导的毒性受到抑制。这些结果表明配体3可作为治疗DM1的先导物。
