Forced alignment of mesenchymal stem cells undergoing cardiomyogenic differentiation affects functional integration with cardiomyocyte cultures.
Alignment of cardiomyocytes (CMCs) contributes to the anisotropic (direction-related) tissue structure of the heart, thereby facilitating efficient electrical and mechanical activation of the ventricles. This study aimed to investigate the effects of forced alignment of stem cells during cardiomyogenic differentiation on their functional integration with CMC cultures. Labeled neonatal rat (nr) mesenchymal stem cells (nrMSCs) were allowed to differentiate into functional heart muscle cells in different cell-alignment patterns during 10 days of coculture with nrCMCs. Development of functional cellular properties was assessed by measuring impulse transmission across these stem cells between 2 adjacent nrCMC fields, cultured onto microelectrode arrays and previously separated by a laser-dissected channel (230+/-10 microm) for nrMSC transplantation. Coatings in these channels were microabraded in a direction (1) parallel or (2) perpendicular to the channel or were (3) left unabraded to establish different cell patterns. Application of cells onto microabraded coatings resulted in anisotropic cell alignment within the channel. Application on unabraded coatings resulted in isotropic (random) alignment. After coculture, conduction across seeded nrMSCs occurred from day 1 (perpendicular and isotropic) or day 6 (parallel) onward. Conduction velocity across nrMSCs at day 10 was highest in the perpendicular (11+/-0.9 cm/sec; n=12), intermediate in the isotropic (7.1+/-1 cm/sec; n=11) and lowest in the parallel configuration (4.9+/-1 cm/sec; n=11) (P<0.01). nrCMCs and fibroblasts served as positive and negative control, respectively. Also, immunocytochemical analysis showed alignment-dependent increases in connexin 43 expression. In conclusion, forced alignment of nrMSCs undergoing cardiomyogenic differentiation affects the time course and degree of functional integration with surrounding cardiac tissue.
Department of Cardiology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
Daniël A
DA
Pijnappels
Martin J
MJ
Schalij
Arti A
AA
Ramkisoensing
John
J
van Tuyn
Antoine A F
AA
de Vries
Arnoud
A
van der Laarse
Dirk L
DL
Ypey
Douwe E
DE
Atsma
D000818:Animals; D002450:Cell Communication / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D018920:Coculture Techniques; D018031:Connexin 43 / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006329:Heart Conduction System / Q000502:physiology*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D008839:Microelectrodes; D023421:Models, Animal; D009206:Myocardium / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar
D018031:Connexin 43