Center for Human Genetic Research, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, CPZN-5254, Boston, MA 02114, USA.
Hum Mol Genet. 2011 Nov 1;20(21):4093-101. doi: 10.1093/hmg/ddr333. Epub 2011 Aug 5.
Recent studies emphasize the importance of mRNA splicing in human genetic disease, as 20-30% of all disease-causing mutations are predicted to result in mRNA splicing defects. The plasticity of the mRNA splicing reaction has made these mutations attractive candidates for the development of therapeutics. Familial dysautonomia (FD) is a severe neurodegenerative disorder, and all patients have an intronic IVS20+6T>C splice site mutation in the IKBKAP gene, which results in tissue-specific skipping of exon 20 and a corresponding reduction in ikappaB kinase complex associated protein (IKAP) levels. We created transgenic mouse lines using a human IKBKAP bacterial artificial chromosome (BAC) into which we inserted the IKBKAP splice mutation (FD BAC) and have shown that the transgenic mice exhibit the same tissue-specific aberrant splicing patterns as seen in FD patients. We have previously demonstrated that the plant cytokinin kinetin can significantly improve the production of wild-type IKBKAP transcripts in FD lymphoblast cell lines by improving exon inclusion. In this study, we tested the ability of kinetin to alter IKBKAP splicing in the transgenic mice carrying the FD BAC and show that it corrects IKBKAP splicing in all major tissues assayed, including the brain. The amount of wild-type IKBKAP mRNA and IKAP protein was significantly higher in the kinetin-treated mice. These exciting results prove that treatment of FD, as well as other mechanistically related splicing disorders, with kinetin holds great promise as a potential therapeutic aimed at increasing normal protein levels, which may, in turn, slow disease progression.
最近的研究强调了 mRNA 剪接在人类遗传疾病中的重要性，因为据预测，所有致病突变中有 20-30%会导致 mRNA 剪接缺陷。mRNA 剪接反应的可塑性使得这些突变成为治疗开发的有吸引力的候选物。家族性自主神经异常症 (FD) 是一种严重的神经退行性疾病，所有患者的 IKBKAP 基因中都存在内含子 IVS20+6T>C 剪接位点突变，导致外显子 20 的组织特异性跳过，以及相应的 ikappaB 激酶复合物相关蛋白 (IKAP) 水平降低。我们使用人类 IKBKAP 细菌人工染色体 (BAC) 创建了转基因小鼠系，我们在该 BAC 中插入了 IKBKAP 剪接突变 (FD BAC)，并表明转基因小鼠表现出与 FD 患者相同的组织特异性异常剪接模式。我们之前已经证明，植物细胞分裂素激动素可以通过改善外显子包含来显著提高 FD 淋巴母细胞系中野生型 IKBKAP 转录物的产生。在这项研究中，我们测试了激动素改变携带 FD BAC 的转基因小鼠中 IKBKAP 剪接的能力，并表明它在所有检测的主要组织中纠正了 IKBKAP 剪接，包括大脑。在激动素处理的小鼠中，野生型 IKBKAP mRNA 和 IKAP 蛋白的量明显更高。这些令人兴奋的结果证明，用激动素治疗 FD 以及其他机制相关的剪接障碍具有很大的潜力，作为一种潜在的治疗方法，旨在增加正常蛋白质水平，这反过来可能会减缓疾病进展。
