A Human 3D Cardiomyocyte Risk Model to Study the Cardiotoxic Influence of X-rays and Other Noxae in Adults.

Timo Smit,Esther Schickel,Christine Von Toerne,Sylvia Ritter,Insa S Schroeder,Marco Durante,Omid Azimzadeh,Oliver Rauh

doi:10.3390/cells10102608

Abstract

The heart tissue is a potential target of various noxae contributing to the onset of cardiovascular diseases. However, underlying pathophysiological mechanisms are largely unknown. Human stem cell-derived models are promising, but a major concern is cell immaturity when estimating risks for adults. In this study, 3D aggregates of human embryonic stem cell-derived cardiomyocytes were cultivated for 300 days and characterized regarding degree of maturity, structure, and cell composition. Furthermore, effects of ionizing radiation (X-rays, 0.1–2 Gy) on matured aggregates were investigated, representing one of the noxae that are challenging to assess. Video-based functional analyses were correlated to changes in the proteome after irradiation. Cardiomyocytes reached maximum maturity after 100 days in cultivation, judged by α-actinin lengths, and displayed typical multinucleation and branching. At this time, aggregates contained all major cardiac cell types, proven by the patch-clamp technique. Matured and X-ray-irradiated aggregates revealed a subtle increase in beat rates and a more arrhythmic sequence of cellular depolarisation and repolarisation compared to non-irradiated sham controls. The proteome analysis provides first insights into signaling mechanisms contributing to cardiotoxicity. Here, we propose an in vitro model suitable to screen various noxae to target adult cardiotoxicity by preserving all the benefits of a 3D tissue culture.

Highlights

Cardiovascular disease (CVD) is the number one cause of death worldwide, including a variety of conditions such as ischemic disease, heart attacks, and conduction abnormalities [1]
The present study aimed to investigate the suitability of aged hPSC-CMC for the risk assessment of different noxae through an in-depth characterization of key features mirroring a physiological and mature myocardium in vitro
Prolonged Cultivation Leads to Maturation of CM within hPSC-CMC To estimate the degree of maturation of the hPSC-CM, the Z-disc protein α-actinin was stained at different time points (25–100 days) after the start of differentiation

Summary

Introduction

Cardiovascular disease (CVD) is the number one cause of death worldwide, including a variety of conditions such as ischemic disease, heart attacks, and conduction abnormalities [1]. Various factors such as dietary, metabolic disorders, and genetic predisposition are reported to increase the risk of developing CVD. Due to a growing patient population receiving ionizing radiation to treat cancerous diseases, adverse effect concerns have arisen based on clinical observations including conduction system abnormalities, cardiomyopathy and pericarditis [3,4]. Underlying mechanisms of radiation-induced cardiovascular diseases are still poorly understood and a more precise risk estimation regarding the cardiovascular system is essential for treatment progression. To date, targeting cardiotoxicity of different noxae is challenging due to a lack of reliable and simple assays

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Conclusion