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+进入各种可激发细胞的关键导管。因此，这些 通道必须精确调整以适合每种单元类型，并响应变化 生理提示。为此，渠道采用多种监管机制，包括替代机制 剪接，依赖电压灭活和钙依赖性失活。但是，越来越多的 突变已在CAV1.2中鉴定出来，导致严重的表型，包括神经功能缺陷，长QT 综合征（LQT）和死亡。蒂莫西综合征（TS）代表一个这样的突变，其中一个突变 Cav1.2内的点突变导致严重的多系统疾病，其特征是发育延迟， 自闭症和深刻的LQT。已显示许多已知的TS突变可降低通道 灭活，将CA2+通道阻滞剂（CCB）视为有前途的治疗选择。但是，尽管有一些 Verapamil的适度成功，CCB在治疗TS方面的疗效有限。在这里，我们假设这种缺乏 功效可能是由于CCB对突变体与野生型Cav1.2的差异作用，因此需要 探索这些患者的替代治疗选择。我们建议操纵CAV1.2拼接 仅代表这样的替代策略，对这些患者的治疗有很大的希望。 具体而言，由于大多数TS患者在相互排斥的外显子内具有突变，我们将设计 针对含有突变的外显子的反义寡核苷酸（AON）。因此，我们希望强迫 排除有害外显子，诱导不受影响的替代外显子包含，并完全产生 功能替代通道剪接变体。重要的是，该策略将绕过当前的局限 常规疗法，为TS患者提供了巨大的临床益处。此外，应用程序 WT CAV1.2渠道的技术可能会导致有希望的新的治疗见解 患者。特别是，我们将应用剪接调节AONS来检验非典型剪接的假设 某些患者的模式可能会使他们更容易受到DHP治疗的有害心脏影响的影响。 最后，由于互斥外显子内发生了许多遗传突变，因此我们将AONS应用于TS 将作为适用于多种蛋白质中众多基因突变的可推广策略。 总体而言，针对蛋白质剪接的有针对性的操纵代表了一个较大尚未开发的机会，提供了一条路径 前进，以治疗各种疾病。