Optimization of compounds to improve mRNA splicing in familial dysautonomia

描述（由申请人提供）：家族性自主神经异常（FD）是一种由IKBKAP基因剪接突变引起的遗传性感觉和自主神经病变。该突变导致IKBKAP mRNA外显子20的可变跳变，从而导致IKAP蛋白的组织特异性减少。FD患者的组织分析显示，神经元组织中显着更多的外显子跳跃，因此IKAP水平较低。IKAP是人类伸长复合体的一个成员，它是基因子集有效转录伸长所必需的。尽管FD是隐性的，但我们已经证明患者保留了制造正常mRNA和蛋白质的能力。这一发现为开发旨在通过剪接修饰提高细胞IKAP水平的疗法提供了一种令人兴奋的直接方法。作为nads资助的神经退行性疾病药物筛选联盟的一部分，我们发现用kinetin（一种植物细胞分裂素）处理培养的FD细胞可以增强外显子20包合，并显著增加FD细胞中野生型IKBKAP mRNA和IKAP蛋白的数量。该化合物疗效显著，可在培养一周内使患者细胞恢复正常IKAP蛋白水平。我们已经证明了动素的能力，改变IKBKAP剪接使用minigene测定在各种细胞类型，以及在人类细胞。最近，我们已经在转基因小鼠和人类FD携带者中显示了体内功效。尽管自主神经异常基金会在开发动素作为FD的潜在治疗方法方面投入了大量资金，但通往临床的道路一直很缓慢，我们仍在研究最初确定的化合物。我们最近生成了一些有希望的SAR（结构和活性关系）数据，表明先导化合物动素的活性可以得到改善。为了提高动素的效力和活性，进行化学优化是至关重要的，时间是至关重要的。尽管FD是一种发育障碍，但患者一生都受到持续、剧烈的神经元变性的困扰。早期有效提高IKAP水平可能有助于神经元的存活

DESCRIPTION (provided by applicant): Familial dysautonomia (FD) is a hereditary sensory and autonomic neuropathy that is caused by a splice mutation in the IKBKAP gene. The mutation results in variable skipping of exon 20 in IKBKAP mRNA, which leads to a tissue-specific reduction of IKAP protein. Analysis of tissues from FD patients shows significantly more exon-skipping in neuronal tissue, and therefore lower IKAP levels. IKAP is a member of the human Elongator complex, which is required for efficient transcriptional elongation of a subset of genes. Despite the fact that FD is recessive, we have shown that patients retain the capacity to make both normal mRNA and protein. This discovery offers an exciting, direct approach towards the development of therapies aimed at increasing levels of cellular IKAP via splicing modification. As part of the NINDS-sponsored Neurodegeneration Drug Screening Consortium, we found that treatment of cultured FD cells with kinetin, a plant cytokinin, enhances exon-20-inclusion and dramatically increases the amount of wild-type IKBKAP mRNA and IKAP protein in FD cells. This compound has remarkable efficacy and can restore normal IKAP protein levels in patient cells within one week in culture. We have demonstrated kinetin's ability to alter IKBKAP splicing using minigene assays in a variety of cell types, as well as in human cells. More recently, we have shown in vivo efficacy in both transgenic mice and in human FD carriers. Despite substantial investment by the Dysautonomia Foundation in developing kinetin as a potential treatment for FD, the road to the clinic has been slow, and we are still working with the originally identified compound. We have recently generated some promising SAR (structure and activity relationship) data showing that the activity of the lead compound kinetin can be improved. It is crucial that chemical optimization be performed in order to improve the potency and activity of kinetin, and time is of the essence. Despite the fact that FD is a developmental disorder, patients are plagued by continued, drastic neuronal degeneration throughout life. Effectively increasing IKAP levels early in life may support neuronal survival and prevent or delay the debilitating gait and sensory and cognitive decline seen in patients as they age. The Blueprint Neurotherapeutics Network offers a unique opportunity for drug development that will provide access to resources that are currently out of reach.