Detect structural cardiotoxicity of novel therapeutics using Cyprotex’s spontaneously beating tri-cultured cardiac 3D microtissue high content screening (HCS) assay.

Cyprotex delivers consistent, high quality data with the flexibility to adapt protocols based on specific customer requirements.

• Drug induced cardiovascular toxicity is the leading cause of attrition during drug development. Drugs can exert functional toxicities such as arrhythmia and morphological (structural) damage to the myocardium¹. Evaluation of the potential for both types of cardiotoxicity by novel compounds is essential for the discovery of safe drugs.
• The myocardial tissue comprises 30% cardiomyocytes and 70% non-myocytes, the majority of which are endothelial and fibroblast cells. These non-myocytes are essential to myocardial structure and function^2,3 with emerging evidence suggesting important roles within drug induced cardiovascular toxicity⁴.
• Mitochondrial disruption, calcium dyshomeostasis and cellular ATP content have been identified as major targets for structural cardiotoxins⁵.
• Three dimensional (3D) confocal HCS allows the simultaneous detection of each cell health parameter in combination with a measure of cellular ATP.

All reference compound toxicities were correctly predicted in the spontaneously beating cardiac tri-culture 3D microtissue model including isoproterenol (MEC 2.1 µM, calcium dyshomeostasis (Table 1 and Figure 2)) and cyclophosphamide (MEC 30.8 µM, mitochondrial mass (Table 1)) which previously went undetected by Pointon et al (2013)⁵ and Cyprotex’s in-house H9c2 data.

Control compound sunitinib displays cytosolic calcium increase (calcium dyshomeostasis) followed by gross cytotoxicity (microtissue loss) (Figure 2a) while control compound dasatinib displays mitochondrial membrane potential loss without gross cytotoxicity (microtissue loss) (Figure 2b). The combination of an in vitro 3D model that better recapitulates the in vivo cellular physiology of the myocardium with a multiparametric HCS and cytotoxicity assay presents a viable screening strategy for the accurate detection of novel therapeutics that cause drug induced structural cardiovascular toxicity early in drug development.

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