Developmental coronary maturation is disturbed by aberrant cardiac vascular endothelial growth factor expression and Notch signalling.
OBJECTIVE
Currently, many potential cardiac revascularization therapies target the vascular endothelial growth factor (VEGF) pathway, with variable success. Knowledge regarding the role of the VEGF/Notch/ephrinB2 cascade in (ab)normal coronary development will provide information on the subtle balance of VEGF signalling in coronary maturation and might enhance our therapeutic possibilities.


RESULTS
The effect of VEGF isoforms on coronary development was explored in vivo using immunohistochemistry and RT-qPCR on Vegf120/120 mouse embryos solely expressing VEGF120. In vitro, human arterial coronary endothelial cells were treated with VEGF121 or VEGF165 upon which RT-qPCR was performed. In vivo, mutant coronary arterial endothelium showed a decrease in protein expression of arterial markers such as cleaved Notch1, Delta-like4, and ephrinB2 concomitant with an increase of venous markers such as chicken ovalbumin upstream promoter transcription factor II. The venous endothelium showed the opposite effect, which was confirmed on the mRNA level. In vitro, mRNA expression of arterial markers highly depended on the VEGF isoform used, with VEGF165 having the strongest effect. Also, coronary arteriogenesis was anomalous in the mouse embryos with decreased arterial and increased venous medial development as shown by staining for smooth muscle alpha-actin, Delta-like1, and Notch3.


CONCLUSIONS
We demonstrate that VEGF isoform-related spatiotemporal cardiac alterations in the VEGF/Notch/ephrinB2 cascade lead to disturbed coronary development. This knowledge can contribute to optimizing therapies targeting VEGF signalling by enabling balancing between angiogenesis and vascular maturation.
van den Akker
Nynke M S
NM
Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, PO Box 9600, 2300 RC Leiden, The Netherlands.
Caolo
Vincenza
V
Wisse
Lambertus J
LJ
Peters
Patricia P W M
PP
Poelmann
Robert E
RE
Carmeliet
Peter
P
Molin
Daniël G M
DG
Gittenberger-de Groot
Adriana C
AC
D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000196:embryology / Q000378:metabolism*; D042783:Endothelial Cells / Q000378:metabolism; D036388:Ephrin-B2 / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006321:Heart / Q000196:embryology*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008822:Mice, Transgenic; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D018919:Neovascularization, Physiologic / Q000235:genetics; D020033:Protein Isoforms / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D042442:Vascular Endothelial Growth Factors / Q000235:genetics / Q000378:metabolism*; D014680:Veins / Q000196:embryology / Q000378:metabolism
D036388:Ephrin-B2; D020033:Protein Isoforms; D012333:RNA, Messenger; D051880:Receptors, Notch; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; C467480:vascular endothelial growth factor A, mouse