CEINGE-Advanced Biotechnologies, Via Gaetano Salvatore 486, 80145 Naples, Italy.
Department of Sciences and Technologies, University of Sannio, Via Port'Arsa 11, 82100 Benevento, Italy.
Biomed Res Int. 2019 Apr 21;2019:7638946. doi: 10.1155/2019/7638946. eCollection 2019.
The skeletal muscle ryanodine receptor (RyR1), i.e., the Ca channel of the sarco/endoplasmic reticulum (S/ER), and the voltage-dependent calcium channel Cav1.1 are the principal channels involved in excitation-contraction coupling in skeletal muscle. gene variants are linked to distinct skeletal muscle disorders, including malignant hyperthermia susceptibility and central core disease (CCD), mainly with autosomal dominant inheritance, and autosomal recessive myopathies with a broad phenotypic and histopathological spectrum. The age at onset of -related myopathies varies from infancy to adulthood. We report the identification of four variants in two Italian families: one with myopathy and variants c.4003C>T (p.R1335C) and c.7035C>A (p.S2345R), and another with CCD and variants c.9293G>T (p.S3098I) and c.14771_14772insTAGACAGGGTGTTGCTCTGTTGCCCTTCTT (p.F4924_V4925insRQGVALLPFF). We demonstrate that, in patient-specific lymphoblastoid cells, the c.4003C>T (p.R1335C) variant is not expressed and the in-frame 30-nucleotide insertion variant is expressed at a low level. Moreover, Ca release in response to the RyR1 agonist 4-chloro-m-cresol and to thapsigargin showed that the c.7035C>A (p.S2345R) variant causes depletion of S/ER Ca stores and that the compound heterozygosity for variant c.9293G>T (p.S3098I) and the 30-nucleotide insertion increases RyR1-dependent Ca release without affecting ER Ca stores. In conclusion, we detected and functionally characterized disease-causing variants of the RyR1 channel in patient-specific lymphoblastoid cells. This paper is dedicated to the memory and contribution of Luigi Del Vecchio.
骨骼肌兰尼碱受体（RyR1），即肌质/内质网（S/ER）的钙通道，以及电压依赖性钙通道 Cav1.1，是骨骼肌兴奋-收缩偶联中主要涉及的通道。RyR1 基因变异与不同的骨骼肌疾病有关，包括恶性高热易感性和中央核疾病（CCD），主要为常染色体显性遗传，以及具有广泛表型和组织病理学谱的常染色体隐性肌病。-相关肌病的发病年龄从婴儿期到成年期不等。我们报告了在两个意大利家族中发现的四个变体：一个家族患有肌病，变体为 c.4003C>T（p.R1335C）和 c.7035C>A（p.S2345R），另一个家族患有 CCD，变体为 c.9293G>T（p.S3098I）和 c.14771_14772insTAGACAGGGTGTTGCTCTGTTGCCCTTCTT（p.F4924_V4925insRQGVALLPFF）。我们证明，在患者特异性淋巴母细胞中，c.4003C>T（p.R1335C）变体不表达，而框内 30 个核苷酸插入变体表达水平较低。此外，RyR1 激动剂 4-氯-间甲酚和 thapsigargin 引起的钙释放表明，c.7035C>A（p.S2345R）变体导致 S/ER 钙库耗竭，并且变体 c.9293G>T（p.S3098I）和 30 个核苷酸插入的复合杂合性增加了 RyR1 依赖性钙释放，而不影响 ER 钙库。总之，我们在患者特异性淋巴母细胞中检测到并功能表征了 RyR1 通道的致病变体。本文献给 Luigi Del Vecchio 的记忆和贡献。
