Next-generation calcium channel modulators

下一代钙通道调节剂

• 批准号: 10323667
• 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/10323667
• 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; Lead; Length; Long QT Syndrome; Molecular Biology; Muscle Cells; Mutation; Neurologic; Neurologic Deficit; Optics; Patients; Pattern; Pharmaceutical Preparations; Phenotype; Physiological; Physiology; Play; Point Mutation; Process; Protein Splicing; Proteins; RNA Splicing; Regulation; Risk; Role; System; Techniques; Testing; Therapeutic; Timothy syndrome; Variant; Ventricular; Verapamil; Work; autism spectrum disorder; base; cell type; channel blockers; common treatment; conventional therapy; design; experimental study; human disease; hypertension treatment; individual response; induced pluripotent stem cell; induced pluripotent stem cell derived cardiomyocytes; insight; mutant; next generation; novel; novel strategies; 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+进入各种可兴奋细胞的关键通道。因此，这些 通道必须精确地调整，以适当地为每种细胞类型发挥作用，并响应于不同的 生理线索为此，这些渠道采用多种监管机制，包括替代监管机制。 剪接、电压依赖性失活和钙依赖性失活。然而，越来越多的 在CaV1.2中发现了突变，导致严重的表型，包括神经功能缺损、长QT间期 综合征（LQTS）和死亡。蒂莫西综合征（TS）代表了一类这样的突变，其中一个单一的 CaV1.2内的点突变导致以发育迟缓为特征的严重多系统障碍， 孤独症和严重的LQTS许多已知的TS突变已被证明可以减少通道 失活，暗示Ca2+通道阻滞剂（CCB）作为一种有前途的治疗选择。然而，尽管一些 维拉帕米取得了一定的成功，但CCB在治疗TS方面的效果有限。在这里，我们假设这种缺乏 有效性的降低可能是由于CCB对突变型与野生型CaV1.2的不同作用， 探索这些患者的替代治疗方案。我们认为操纵CaV1.2剪接 代表了这样一种替代策略，对这些患者的治疗有着重大的希望。 具体而言，由于大多数TS患者在互斥外显子内具有突变，我们将设计 反义寡核苷酸（AON）靶向含有突变的外显子。因此，我们希望 排除有害外显子，诱导包含未受影响的替代外显子，并产生完全的 功能交替通道拼接变体。重要的是，这一战略将绕过目前的限制， 常规疗法，为TS患者提供显著的临床益处。此外，应用此 WT CaV1.2通道的技术可能会在更广泛的人群中产生有希望的新的治疗见解。 患者特别地，我们将应用我们的剪接调节AON来检验非典型剪接 某些患者的模式可能使他们更容易受到DHP治疗的有害心脏影响。 最后，由于许多基因突变发生在相互排斥的外显子中，我们将AON应用于TS 将作为适用于多种蛋白质中的多种基因突变的可推广策略。 总的来说，蛋白质剪接的靶向操纵代表了一个巨大的未开发的机会， 用于治疗多种疾病。