Incomplete Assembly of the Dystrophin-Associated Protein Complex in 2D and 3D-Cultured Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

Guillaume Gilbert,Chandan Kadur Nagaraju,Matthew Amoni,Maurilio Sampaolesi,Karin R Sipido,Pierre Bobin,Robin Duelen,Thomas Eschenhagen,H Llewelyn Roderick

doi:10.3389/fcell.2021.737840

Abstract

Human induced pluripotent stem cells derived cardiomyocytes (hiPSC-CM) are increasingly used to study genetic diseases on a human background. However, the lack of a fully mature adult cardiomyocyte phenotype of hiPSC-CM may be limiting the scope of these studies. Muscular dystrophies and concomitant cardiomyopathies result from mutations in genes encoding proteins of the dystrophin-associated protein complex (DAPC), which is a multi-protein membrane-spanning complex. We examined the expression of DAPC components in hiPSC-CM, which underwent maturation in 2D and 3D culture protocols. The results were compared with human adult cardiac tissue and isolated cardiomyocytes. We found that similarly to adult cardiomyocytes, hiPSC-CM express dystrophin, in line with previous studies on Duchenne’s disease. β-dystroglycan was also expressed, but, contrary to findings in adult cardiomyocytes, none of the sarcoglycans nor α-dystroglycan were, despite the presence of their mRNA. In conclusion, despite the robust expression of dystrophin, the absence of several other DAPC protein components cautions for reliance on commonly used protocols for hiPSC-CM maturation for functional assessment of the complete DAPC.

Highlights

Muscular dystrophies are genetically inherited degenerative disorders with a progressive impairment of skeletal, respiratory, and cardiac function (Mercuri et al, 2019)
HiPSC-CM generated via some of these methods have been used in the study of Duchenne muscular dystrophy (Long et al, 2018; Pioner et al, 2020), yet it has been suggested that dystrophin is needed for hiPSC-CM maturation (Pioner et al, 2020), and presently it is unknown whether the dystrophin-associated protein complex (DAPC) in hiPSC-CM forms a complete functional complex
HiPSC-CM generated using a common 2D monolayer protocol expressed an incomplete DAPC with only dystrophin and β-dystroglycan present (Figure 2A, left)

Summary

INTRODUCTION

Muscular dystrophies are genetically inherited degenerative disorders with a progressive impairment of skeletal, respiratory, and cardiac function (Mercuri et al, 2019). Because of the unavailability of cardiac biopsies from those patients, there remains a knowledge gap in the understanding of the cellular mechanisms underlying cardiomyopathy in humans, hampering clinical translation To overcome this limitation, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are increasingly used as a model. HiPSC-CM generated via some of these methods have been used in the study of Duchenne muscular dystrophy (Long et al, 2018; Pioner et al, 2020), yet it has been suggested that dystrophin is needed for hiPSC-CM maturation (Pioner et al, 2020), and presently it is unknown whether the DAPC in hiPSC-CM forms a complete functional complex. The data are compared with the hiPSC-CM differentiated in 2D without an intensified maturation protocol, and with adult human cardiac tissue

METHOD

RESULTS AND DISCUSSION

ETHICS STATEMENT