Cardiomyocytes differentiated in vitro from embryonic stem cells developmentally express cardiac-specific genes and ionic currents.

• DOI: 10.1161/01.res.75.2.233
• Publication Date: 2012-06-12T00:47:05Z
• Authors: V A Maltsev; A M Wobus; J Rohwedel; M Bader; J Hescheler
• Keywords: Embryoid body

Cardiomyocytes differentiated in vitro from pluripotent embryonic stem (ES) cells of line D3 via embryo-like aggregates (embryoid bodies) were characterized by the whole-cell patch-clamp technique during entire differentiation period. Spontaneously contracting cardiomyocytes enzymatically isolated collagenase embryoid body outgrowths early, intermediate, and terminal stages. The early exhibited an outwardly rectifying, transient K+ current sensitive to 4-aminopyridine inward Ca2+ but no Na+ current. showed all features L-type current, being highly 1,4-dihydropyridines not omega-conotoxin. intermediate stage additional expression cardiac-specific delayed If Terminally expressed a channel density about three times higher than that stage. In addition, two types inwardly rectifying currents (IK1 IK,Ach) ATP-modulated found. During cardiomyocyte differentiation, several distinct cell populations could be distinguished their sets ionic channels typical action potentials presumably representing cardiac tissues with properties sinus node, atrium, ventricle. Reverse transcription polymerase chain reaction revealed alpha- beta-cardiac myosin heavy (MHC) genes synchronously first spontaneous contractions. Transcription skeletal MHC gene at stages correlated channels. selective alpha-cardiac ES cell-derived was demonstrated after transfection LacZ construct driven promoter region followed beta-galactosidase staining. conclusion, our data demonstrate represent unique model investigate development permit pharmacological/toxicological studies vitro.