Faculty Collaboration Database

Altered contractility, Ca²⁺ transients, and cell morphology seen in a patient-specific iPSC-CM model of Ebstein's anomaly with left ventricular noncompaction. Am J Physiol Heart Circ Physiol 2023 Jul 01;325(1):H149-H162

Date

05/19/2023

Pubmed ID

37204873

Pubmed Central ID

PMC10312315

DOI

10.1152/ajpheart.00658.2022

Scopus ID

2-s2.0-85164047409 (requires institutional sign-in at Scopus site)

Abstract

Patients with two congenital heart diseases (CHDs), Ebstein's anomaly (EA) and left ventricular noncompaction (LVNC), suffer higher morbidity than either CHD alone. The genetic etiology and pathogenesis of combined EA/LVNC remain largely unknown. We investigated a familial EA/LVNC case associated with a variant (p.R237C) in the gene encoding Kelch-like protein 26 (KLHL26) by differentiating induced pluripotent stem cells (iPSCs) generated from affected and unaffected family members into cardiomyocytes (iPSC-CMs) and assessing iPSC-CM morphology, function, gene expression, and protein abundance. Compared with unaffected iPSC-CMs, CMs containing the KLHL26 (p.R237C) variant exhibited aberrant morphology including distended endo(sarco)plasmic reticulum (ER/SR) and dysmorphic mitochondria and aberrant function that included decreased contractions per minute, altered calcium transients, and increased proliferation. Pathway enrichment analyses based on RNASeq data indicated that the "structural constituent of muscle" pathway was suppressed, whereas the "ER lumen" pathway was activated. Taken together, these findings suggest that iPSC-CMs containing this KLHL26 (p.R237C) variant develop dysregulated ER/SR, calcium signaling, contractility, and proliferation.NEW & NOTEWORTHY We demonstrate here that iPSCs derived from patients with Ebstein's anomaly and left ventricular noncompaction, when differentiated into cardiomyocytes, display significant structural and functional changes that offer insight into disease pathogenesis, including altered ER/SR and mitochondrial morphology, contractility, and calcium signaling.

Author List

Thareja SK, Anfinson M, Cavanaugh M, Kim MS, Lamberton P, Radandt J, Brown R, Liang HL, Stamm K, Afzal MZ, Strande J, Frommelt MA, Lough JW, Fitts RH, Mitchell ME, Tomita-Mitchell A

Authors

Michele Ann Frommelt MD Adjunct Professor in the Pediatrics department at Medical College of Wisconsin
John W. Lough PhD Professor in the Cell Biology, Neurobiology and Anatomy department at Medical College of Wisconsin
Michael Edward Mitchell MD Chief, Professor in the Surgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Calcium Signaling
Cell Differentiation
Ebstein Anomaly
Humans
Induced Pluripotent Stem Cells
Myocytes, Cardiac