Endothelial cells promote cardiac myocyte survival and spatial reorganization: implications for cardiac regeneration.
BACKGROUND
Endothelial-cardiac myocyte (CM) interactions play a key role in regulating cardiac function, but the role of these interactions in CM survival is unknown. This study tested the hypothesis that endothelial cells (ECs) promote CM survival and enhance spatial organization in a 3-dimensional configuration.


RESULTS
Microvascular ECs and neonatal CMs were seeded on peptide hydrogels in 1 of 3 experimental configurations: CMs alone, CMs mixed with ECs (coculture), or CMs seeded on preformed EC networks (prevascularized). Capillary-like networks formed by ECs promoted marked CM reorganization along the EC structures, in contrast to limited organization of CMs cultured alone. The presence of ECs markedly inhibited CM apoptosis and necrosis at all time points. In addition, CMs on preformed EC networks resulted in significantly less CM apoptosis and necrosis compared with simultaneous EC-CM seeding (P<0.01, ANOVA). Furthermore, ECs promoted synchronized contraction of CMs as well as connexin 43 expression.


CONCLUSIONS
These results provide direct evidence for a novel role of endothelium in survival and organization of nearby CMs. Successful strategies for cardiac regeneration may therefore depend on establishing functional CM-endothelium interactions.
Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA.
Daria A
DA
Narmoneva
Rada
R
Vukmirovic
Michael E
ME
Davis
Roger D
RD
Kamm
Richard T
RT
Lee
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured / Q000166:cytology; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology; D005347:Fibroblasts / Q000166:cytology; D006321:Heart / Q000502:physiology; D020100:Hydrogels; D008168:Lung / Q000166:cytology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018715:Microscopy, Video; D009024:Morphogenesis; D009200:Myocardial Contraction; D032383:Myocytes, Cardiac / Q000166:cytology*; D009336:Necrosis; D051381:Rats; D012038:Regeneration; D023822:Tissue Engineering
D020100:Hydrogels