COMPOSITIONS AND METHODS FOR DETECTING CARDIOTOXICITY
A method of screening a composition for cardiotoxicity comprising contacting the composition with cardiomyocytes that have increased fatty acid oxidation and/or diminished glucose oxidation. The cardiomyocytes are preferably prepared by overexpression of COX7A1. The cardiomyocytes are preferably provided in a micropatterned co-culture to provide a mature functional hPSC-CM cardiotoxicity model.
1 . A method of screening a composition for cardiotoxicity comprising contacting the composition with cardiomyocytes, wherein cells used to generate the cardiomyocytes were transfected with COX7A1, wherein the cardiomyocytes have increased fatty acid oxidation and/or diminished glucose oxidation relative to cardiomyocytes differentiated from a human embryonic stem cell line not transfected with COX7A1, wherein the cardiomyocytes are matured by overexpression of COX7A1.
2 . (canceled)
3 . (canceled)
4 . The method of claim 1 , wherein the cardiomyocytes are derived from a human induced pluripotent stem cell line.
5 . A composition comprising a cardiomyocyte or a population of cardiomyocytes that primarily utilize fatty acids as an energy source, wherein a cell or cells used to generate the cardiomyocyte or the population of cardiomyocytes were transfected with COX7A1, and wherein the cardiomyocyte or the population of cardiomyocytes are matured by overexpression of COX7A1.
6 . A method of generating a mature cardiomyocyte or a population of mature cardiomyocytes comprising transfecting a human pluripotent stem cell line with COX7A1, differentiating the transfected cells to produce cardiomyocytes, and maturing the cardiomyocytes via overexpression of COX7A1.
7 . The method of claim 6 , wherein the mature cardiomyocyte or the population of mature cardiomyocytes have increased fatty acid oxidation and/or diminished glucose oxidation relative to cardiomyocytes differentiated from a human embryonic stem cell line not transfected with COX7A1.
8 . The method of claim 6 , wherein the mature cardiomyocyte or the population of mature cardiomyocytes have an increased expression in one or more of CSQ, PLN, RYR2, SERCA/ATP2A2, MyH7, TNNI3, and ADRA1A and/or a decreased expression of one or more of MYH6 and TNNI1 than cardiomyocytes not overexpressing COX7A1.
9 . The method of claim 6 , wherein COX7A1 is transfected by a knock-in inducible COX7A1 expression cassette.
10 . The method of claim 6 , wherein COX7A1 is available by constitutive expression.
11 . The method of claim 1 , wherein the screening is conducted in a culture vessel wherein the cardiomyocytes are on a micropatterned surface that orients the cardiomyocytes in a specific pattern.
12 . The method of claim 11 , wherein the cardiomyocytes on the micropatterned surface are ventricular cardiomyocytes.
13 . The method of claim 11 , wherein ventricular cardiomyocytes on the micropatterned surface have at least one contact point with nodal cells.
14 . The method of claim 11 , wherein the micropatterned surface comprises fibronectin.
15 . The method of claim 11 , wherein the cardiomyocytes are cocultured with at least one secondary cell capable of increasing cardiomyocyte maturity.