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钙通道是钙离子进入多种可兴奋细胞的重要通道。因此，这些 必须对频道进行精确的调谐，以适合每种细胞类型的功能，并响应变化 生理暗示。为此，渠道采用了多种监管机制，包括替代机制 剪接、电压依赖性失活和钙依赖性失活。然而，越来越多的 已在CaV1.2中发现突变，导致严重的表型，包括神经缺陷、长QT 综合征(LQTS)和死亡。Timothy综合征(TS)代表这样一类突变，在这种突变中，单个 CaV1.2内的点突变导致以发育延迟为特征的严重多系统障碍， 自闭症和严重的LQTS。许多已知的TS突变已被证明会降低通道 失活，暗示钙通道阻滞剂(CCB)是一种有前途的治疗选择。然而，尽管有一些 维拉帕米取得了不大的成功，CCBS在治疗TS方面的疗效有限。在这里，我们假设这种缺乏 药效的降低可能是由于CCBS对突变体CaV1.2和野生型CaV1.2的不同影响，使得 为这些患者探索替代治疗方案。我们建议操纵CaV1.2剪接 就代表了这样一种替代策略，对这些患者的治疗有着重大的前景。 具体地说，由于大多数TS患者在相互排斥的外显子中存在突变，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，我们预计将迫使 排除有害的外显子，诱导包含未受影响的交替外显子，并产生完全的 功能替代通道拼接变体。重要的是，这一策略将绕过当前 传统疗法，为TS患者提供显著的临床益处。此外，这一点的应用 WT CaV1.2渠道的技术可能会在更广泛的人群中带来有希望的新治疗见解 病人。特别是，我们将应用我们的剪接调节AON来测试非典型剪接的假设 一些患者的模式可能使他们更容易受到DHP治疗的不利心脏影响。 最后，由于大量的基因突变发生在互斥的外显子内，我们将AONS应用于TS 将作为一种可推广的策略，适用于多种蛋白质中的许多基因突变。 总体而言，蛋白质剪接的定向操作代表着一个巨大的尚未开发的机会，提供了一条途径 用于治疗一系列不同疾病。