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Electrophysiological Analysis of human Pluripotent Stem Cell-derived Cardiomyocytes hPSC-CMs Using Multi-electrode Arrays MEAs
Published on: May 12, 2017
Adipocyte-Mediated Electrophysiological Remodeling of PKP-2 Mutant Human Pluripotent Stem Cell-Derived Cardiomyocytes
Justin Morrissette-McAlmon1, Christianne J Chua1, Alexander Arking1
1Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Insights
Fatty tissue secretions alter heart cell electrical activity in arrhythmogenic cardiomyopathy (ACM). These paracrine factors impact normal and ACM cells differently, potentially worsening the condition.
Area of Science:
- Cardiovascular Research
- Genetic Cardiology
- Stem Cell Biology
Background:
- Arrhythmogenic cardiomyopathy (ACM) is a genetic heart condition causing sudden cardiac death, linked to desmosome mutations.
- ACM leads to right ventricular dysfunction, cardiomyocyte loss, and fibrofatty replacement, affecting heart stability.
- The impact of paracrine factors from infiltrating fatty tissues on ACM cardiomyocyte electrophysiology remains unclear.
Purpose of the Study:
- To investigate how paracrine factors from adipose tissue affect the electrophysiology of cardiomyocytes in arrhythmogenic cardiomyopathy.
- To compare the responses of normal and ACM patient-derived induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to these factors.
Main Methods:
- hiPSC-CMs from normal and PKP2 mutant ACM lines were cultured with adipocyte-conditioned medium (AdCM) or specific cytokines.
- Optical mapping and phenotypic analyses assessed electrophysiological parameters like action potential duration (APD) and conduction velocity (CV).
- NF-kB signaling pathways were also examined in response to AdCM and IL-6.
Main Results:
- AdCM significantly altered APD and CV in both normal and ACM hiPSC-CMs, with differing magnitudes and time courses.
- Specific cytokines (IL-6, IL-8, MCP-1, CFD) induced distinct, sometimes opposite, electrophysiological effects in normal versus mutant hiPSC-CMs.
- NF-kB signaling pathways showed differential responses between normal and ACM hiPSC-CMs exposed to AdCM and IL-6.
Conclusions:
- hiPSC-CMs from normal and ACM individuals exhibit unique molecular and functional responses to paracrine factors.
- These differential responses in electrophysiology and gene expression may contribute to the arrhythmogenic nature of ACM.
- Paracrine signaling from adipose tissue represents a potential therapeutic target for ACM.
Background:
Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder responsible for nearly a quarter of sports-related sudden cardiac deaths. ACM cases caused by mutations in desmosome proteins lead to right ventricular enlargement, the loss of cardiomyocytes, and fibrofatty tissue replacement, disrupting electrical and mechanical stability. It is currently unknown how paracrine factors secreted by infiltrating fatty tissues affect ACM cardiomyocyte electrophysiology.
Methods:
A normal and a PKP2 mutant (c.971_972InsT) ACM hiPSC line were cultivated and differentiated into cardiomyocytes (CMs). Adipocytes were differentiated from human adipose stem cells, and adipocyte conditioned medium (AdCM) was collected. Optical mapping and phenotypic analyses were conducted on human iPSC-cardiomyocytes (hiPSC-CMs) cultured in cardiac maintenance medium (CMM) and either with AdCM or specific cytokines.
Results:
Significant differences were observed in voltage parameters such as the action potential duration (APD80, APD30), conduction velocity (CV), and CV heterogeneity. When cultured in AdCM relative to CMM, the APD80 increased and the CV decreased significantly in both groups; however, the magnitudes of changes often differed significantly between 1 and 7 days of cultivation. Cytokine exposure (IL-6, IL-8, MCP-1, CFD) affected the APD and CV in both the normal and PKP2 mutant hiPSC-CMs, with opposite effects. NF-kB signaling was also found to differ between the normal and PKP2 mutant hiPSC-CMs in response to AdCM and IL-6.
Conclusions:
Our study shows that hiPSC-CMs from normal and mPKP2 ACM lines exhibit distinct molecular and functional responses to paracrine factors, with differences in RNA expression and electrophysiology. These different responses to paracrine factors may contribute to arrhythmogenic propensity.
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