Systems and methods for modeling disease and assessing adverse side effects of therapeutics therefor
The disclosure provides a substrate for the ordered growth and development of cardiomyocytes such as ventricular cardiomyocytes derived from pluripotent stem cells along with methods of culturing the cells on the substrates for use in assays such as cardiotoxicity assays. Further provided are methods for assessing cardiotoxicity using one or more criteria disclosed herein.
1 . A method of assessing whether a compound exhibits cardiotoxicity comprising:
(a) contacting an anisotropic layer of ventricular cardiac cells comprising at least 70% troponin T+ cardiomyocytes on a microfabricated substrate comprising microgrooves oriented along a single axis of the substrate with a compound, wherein microgrooves have a width of 15 μm and a depth 5 μm and wherein spacing between microgrooves is 5 μm;
(b) electrically stimulating the anisotropic layer of cardiac cells at one or more points by a programmed electrical stimulation comprising delivering a train of eight S1 stimuli at 1.5 Hertz, followed by a premature extra stimulus S2 with an S1-S2 interval initiated at 550 milliseconds (ms) and consecutively shortened in steps of 50 ms until capture fails, at which point the S1-S2 interval is increased by 20 ms, followed by 2 ms decrements until an effective refractory period is achieved when the maximum S1-S2 interval fails to lead to action potential propagation and a radiating conduction pattern with an anisotropic ratio of at least 1.8 in response to electrical point stimulation;
(c) detecting an electrical signal propagation in the anisotropic layer of cardiac cells;
(d) determining whether the electrical signal propagation is an arrhythmic reentrant event; and
(e) identifying the compound as exhibiting cardiotoxicity if the electrical signal propagation is an arrhythmic reentrant event.
2 . The method of claim 1 , wherein the anisotropic layer of cells comprises patient- or disease-specific cardiac cells derived from a human.
3 . The method of claim 1 , wherein the microfabricated substrate is polystyrene.
4 . The method of claim 1 , wherein the anisotropic layer of cardiac cells is stimulated at one point.
5 . The method of claim 4 , wherein the stimulation is 5-30 volts with a pulse duration of 5-30 milliseconds.
6 . The method of claim 5 , wherein the stimulation is 10 volts with a pulse duration of 10 milliseconds.
7 . The method of claim 1 , wherein a compound is determined to exhibit cardiotoxicity if the compound induces a spiral electrical propagation wave in the anisotropic layer of cardiac cells.
8 . The method of claim 1 , wherein the compound is a Class 1A, Class 1B or Class 1C anti-arrhythmic compound.
9 . A method for assessing whether a compound is cardiotoxic, the method comprising
(a) contacting an anisotropic layer of ventricular cardiac cells comprising at least 70% troponin T+ cardiomyocytes on a microfabricated substrate comprising microgrooves oriented along a single axis of the substrate with a compound, wherein microgrooves have a width of 15 μm and a depth 5 μm and wherein spacing between microgrooves is 5 μm; and
(b) determining the compound is cardiotoxic if the compound induces an arrhythmic reentrant event in the cardiac cells after administering a programmed electrical stimulation comprising a train of eight S1 stimuli delivered at 1.5 Hertz followed by a premature extra stimulus S2 with S1-S2 interval initiated at 550 milliseconds (ms) and consecutively shortened in steps of 50 ms until capture fails, at which point the S1-S2 interval is increased by 20 ms, followed by 2 ms decrements until the effective refractory period is achieved when the maximum S1-S2 interval fails to lead to action potential propagation.
10 . The method of claim 9 , wherein the cardiac cells are attached to the microfabricated substrate.
11 . The method of claim 9 , wherein the anisotropic layer of cardiac cells are healthy cells.
12 . The method of claim 9 , wherein the anisotropic layer of cardiac cells are genetically, chemically, physically or electrically disposed to a cardiac arrhythmia or disease.
13 . The method of claim 12 , wherein the cardiac arrhythmia or disease is or results from Long QT syndrome, Brugada syndrome, genetic heart disease, amyloidosis, progeria, diabetic coma, jellyfish intoxication, hyperthyroidism, Yellow Fever, Chagas disease, aortic valve regurgitation, prescription drug abuse, Rett syndrome, myocarditis, tricuspid atresia, Lyme disease, Churg-Strauss syndrome, forms of heart disease or failure involving arrhythmia, enlarged heart, broken heart syndrome, thyroid nodules, atrioventricular canal defect, cholera, mitral valve stenosis, multiple system atrophy (MSA), snoring, mitral valve prolapse, amniotic fluid embolism, gangrene, aplastic anemia, congenital heart disease in adults, heat exhaustion, Graves' disease, cardiomyopathy, premature ventricular contractions, Bradycardia, fatigue, tachycardia, dizziness, or shortness of breath.