Comparing human iPSC-cardiomyocytes versus HEK293T cells unveils disease-causing effects of Brugada mutation A735V of NaV1.5 sodium channels

Summary

Loss-of-function mutations of the SCN5A gene encoding for the sodium channel α-subunit NaV1.5 result in the autosomal dominant hereditary disease Brugada Syndrome (BrS) with a high risk of sudden cardiac death in the adult. We here engineered human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) carrying the CRISPR/Cas9 introduced BrS-mutation p.A735V-NaV1.5 (g.2204C > T in exon 14 of SCN5A) as a novel model independent of patient´s genetic background. Recent studies raised concern regarding the use of hiPSC-CMs for studying adult-onset hereditary diseases due to cells' immature phenotype. To tackle this concern, long-term cultivation of hiPSC-CMs on a stiff matrix (27-42 days) was applied to promote maturation. Patch clamp recordings of A735V mutated hiPSC-CMs revealed a substantially reduced upstroke velocity and sodium current density, a prominent rightward shift of the steady state activation curve and decelerated recovery from inactivation as compared to isogenic hiPSC-CMs controls. These observations were substantiated by a comparative study on mutant A735V-NaV1.5 channels heterologously expressed in HEK293T cells. In contrast to mutated hiPSC-CMs, a leftward shift of sodium channel inactivation was not observed in HEK293T, emphasizing the importance of investigating mechanisms of BrS in independent systems. Overall, our approach supports hiPSC-CMs' relevance for investigating channelopathies in a dish.

Authors de la Roche J, Angsutararux P, Kempf H, Janan M, Bolesani E, Thiemann S, Wojciechowski D, Coffee M, Franke A, Schwanke K, Leffler A, Luanpitpong S, Issaragrisil S, Fischer M, Zweigerdt R
Journal Scientific reports
Publication Date 2019 Aug 1;9(1):11173
PubMed 31371804
PubMed Central PMC6673693
DOI 10.1038/s41598-019-47632-4

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