| First Author | Estes SI | Year | 2019 |
| Journal | Circ Genom Precis Med | Volume | 12 |
| Issue | 8 | Pages | e002534 |
| PubMed ID | 31430211 | Mgi Jnum | J:352575 |
| Mgi Id | MGI:7707630 | Doi | 10.1161/CIRCGEN.119.002534 |
| Citation | Estes SI, et al. (2019) Characterization of the CACNA1C-R518C Missense Mutation in the Pathobiology of Long-QT Syndrome Using Human Induced Pluripotent Stem Cell Cardiomyocytes Shows Action Potential Prolongation and L-Type Calcium Channel Perturbation. Circ Genom Precis Med 12(8):e002534 |
| abstractText | BACKGROUND: The CACNA1C-encoded cardiac L-type calcium channel (Cav1.2) is essential for cardiocyte action potential duration (APD). We previously reported the CACNA1C-p.R518C variant associated with prolonged QT intervals, cardiomyopathy, and sudden cardiac death in several pedigrees. METHODS: To characterize a patient-derived human induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) CACNA1C-p.R518C model, CACNA1C-p.R518C hiPSC-CMs were generated from a 13-year-old man (QTc, >480 ms) with a family history of sudden cardiac death. An isogenic hiPSC-CM gene-corrected control was created using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat-associated 9). APD and calcium handling were assessed by live cell imaging with Arclight voltage and Fluo-4 calcium indicators, respectively. The APD and L-type calcium channel biophysical properties were further assessed by whole-cell patch clamp technique. RESULTS: The Bazett formula-corrected, Arclight-measured APD(90) of CACNA1C-p.R518C hiPSC-CMs was significantly longer (622+/-11 ms; n=92) than the isogenic control hiPSC-CMs (453+/-5 ms; n=62; P<0.0001). Patch clamp assessment of CACNA1C-p.R518C hiPSC-CMs paced at 1 Hz confirmed a prolonged APD(90) (689+/-29 ms; n=10) compared with the patient's isogenic control hiPSC-CMs (434+/-30 ms; n=8; P<0.05). Fluo-4-measured calcium transient decay time suggested calcium mishandling in CACNA1C-p.R518C. Patch clamp analysis revealed increased L-type calcium channel window current, slow decay time at various voltages, and increased late calcium current for CACNA1C-p.R518C hiPSC-CMs when compared with isogenic control hiPSC-CMs. CONCLUSIONS: Using patient-specific hiPSC-CM mutant and isogenic control lines, we demonstrate that the CACNA1C-p.R518C variant is the self-sufficient, monogenetic substrate for the patient's long-QT syndrome phenotype. These data further bolster the conclusion that CACNA1C is a bona fide, definite evidence long-QT syndrome susceptibility gene. |
