Next-generation calcium channel modulators

下一代钙通道调节剂

• 批准号: 10526425
• 负责人: Ivy E Dick
• 金额: $ 38.63万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-20 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10526425
• 关键词: Action Potentials; Adult; Alternative Splicing; Antisense Oligonucleotides; Biophysics; Bypass; Calcium; Calcium Channel; Cardiac; Cavia; Cells; Cessation of life; Clinical; Complement; Computer Models; Cues; DNA Sequence Alteration; Developmental Delay Disorders; Dihydropyridines; Disease; Electrophysiology (science); Exclusion; Exons; Genetic Diseases; Human; Image; Ion Channel; Length; Long QT Syndrome; Maps; Molecular Biology; Muscle Cells; Mutation; Neurologic; Neurologic Deficit; Optics; Patients; Pattern; Pharmaceutical Preparations; Phenotype; Physiological; Physiology; Play; Point Mutation; Predisposition; Process; Protein Splicing; Proteins; RNA Splicing; Regulation; Risk; Role; System; Techniques; Testing; Therapeutic; Timothy syndrome; Variant; Ventricular; Verapamil; Work; autism spectrum disorder; cell type; channel blockers; common treatment; conventional therapy; design; experimental study; human disease; hypertension treatment; improved; individual response; induced pluripotent stem cell derived cardiomyocytes; insight; mutant; next generation; novel; novel strategies; novel therapeutic intervention; novel therapeutics; patch clamp; patient population; patient response; patient subsets; response; small molecule; success; tool; treatment strategy; voltage

CaV1.2 Ca2+ channels are critical conduits for Ca2+ entry into a diverse array of excitable cells. As such, these channels must be precisely tuned to function appropriately for each cell type, and in response to varying physiological cues. To this end, the channels employ multiple mechanisms of regulation, including alternative splicing, voltage dependent inactivation and calcium dependent inactivation. However, a growing number of mutations have been identified in CaV1.2, leading to severe phenotypes including neurological deficits, long-QT syndrome (LQTS), and death. Timothy Syndrome (TS) represents one such class of mutations, in which a single point mutation within CaV1.2 leads to a severe multisystem disorder characterized by developmental delays, autism and profound LQTS. Many of the known TS mutations have been shown to decrease channel inactivation, implicating Ca2+ channel blockers (CCBs) as a promising treatment option. However, despite some modest success with verapamil, CCBs have had limited efficacy in treating TS. Here, we postulate that this lack of efficacy may be due to a differential effect of CCBs on mutant versus wild type CaV1.2, necessitating the exploration of alternative therapeutic options for these patients. We propose that manipulating CaV1.2 splicing represents just such an alternative strategy, with significant promise for the treatment of these patients. Specifically, as the majority of TS patients harbor a mutation within a mutually exclusive exon, we will design antisense oligonucleotides (AONs) targeted to the exon containing the mutation. As such, we expect to force the exclusion of the deleterious exon, induce inclusion of the unaffected alternate exon, and produce a fully functional alternate channel splice variant. Importantly, this strategy will bypass the current limitations of conventional therapies, providing significant clinical benefit for TS patients. Moreover, application of this technique to WT CaV1.2 channels may lead to promising new therapeutic insights within a broader population of patients. In particular, we will apply our splice modulating AONs to test the hypothesis that atypical splice patterns in some patients may render them more susceptible to detrimental cardiac effects of DHP treatment. Finally, as numerous genetic mutations occur within mutually exclusive exons, our application of AONs to TS will serve as a generalizable strategy applicable to numerous genetic mutations in a multitude of proteins. Overall, targeted manipulation of protein splicing represents a large and untapped opportunity, providing a path forward for treatment of a diverse array of diseases.

CaV1.2 Ca2+ 通道是 Ca2+ 进入多种可兴奋细胞的关键通道。因此，这些 通道必须精确调整，以适应每种细胞类型的功能，并响应变化的 生理线索。为此，渠道采用多种监管机制，包括替代性监管机制 剪接、电压依赖性失活和钙依赖性失活。然而，越来越多的 CaV1.2 中已发现突变，导致严重的表型，包括神经功能缺损、长 QT 综合征（LQTS）和死亡。蒂莫西综合症 (TS) 代表了一类突变，其中单个突变 CaV1.2 内的点突变会导致严重的多系统疾病，其特征是发育迟缓， 自闭症和深刻的 LQTS。许多已知的 TS 突变已被证明会减少通道 失活，表明 Ca2+ 通道阻滞剂 (CCB) 是一种有前途的治疗选择。然而，尽管有一些 虽然维拉帕米取得了一定的成功，但 CCB 在治疗 TS 方面的功效有限。在这里，我们假设这种缺失 功效的差异可能是由于 CCB 对突变型与野生型 CaV1.2 的影响不同，因此需要 探索这些患者的替代治疗方案。我们建议操纵 CaV1.2 剪接 代表了这样一种替代策略，为这些患者的治疗带来了巨大的希望。 具体来说，由于大多数 TS 患者在相互排斥的外显子内存在突变，我们将设计 针对包含突变的外显子的反义寡核苷酸（AON）。因此，我们希望强制 排除有害的外显子，诱导包含未受影响的替代外显子，并产生完全的 功能性备用通道拼接变体。重要的是，该策略将绕过当前的限制 传统疗法，为 TS 患者提供显着的临床益处。此外，应用本 WT CaV1.2 通道技术可能会在更广泛的人群中带来有希望的新治疗见解 患者。特别是，我们将应用我们的剪接调制 AON 来检验非典型剪接的假设 一些患者的模式可能使他们更容易受到 DHP 治疗对心脏的不利影响。 最后，由于许多基因突变发生在相互排斥的外显子内，我们将 AON 应用于 TS 将作为适用于多种蛋白质中的众多基因突变的通用策略。 总的来说，蛋白质剪接的靶向操作代表了一个巨大的、尚未开发的机会，提供了一条途径 有望治疗多种疾病。