The remodeling of cardiovascular bioprostheses under influence of stem cell homing signal pathways.
Optimizing current heart valve replacement strategies by creating living prostheses is a necessity to alleviate complications with current bioprosthetic devices such as calcification and degeneration. Regenerative medicine, mostly in vitro tissue engineering, is the forerunner of this optimization search, yet here we show the functionality of an in vivo alternative making use of 2 homing axes for stem cells. In rats we studied the signaling pathways of stem cells on implanted bioprosthetic tissue (photooxidized bovine pericardium (POP)), by gene and protein expression analysis. We found that SDF-1alpha/CXCR4 and FN/VLA4 homing axes play a role. When we implanted vascular grafts impregnated with SDF-1alpha and/or FN as carotid artery interpositions, primitive cells were attracted from the circulation. Next, bioprosthetic heart valves, constructed from POP impregnated with SDF-1alpha and/or FN, were implanted in pulmonary position. As shown by CD90, CD34 and CD117 immunofluorescent staining they became completely recellularized after 5 months, had a normal function and biomechanical properties and specifically the combination of SDF-1alpha and FN had an optimal valve-cell phenotype.
Laboratory for Experimental Cardiac Surgery, Department of Cardiovascular Diseases, Katholieke Universiteit Leuven, Leuven, Belgium. geofrey.devisscher@med.kuleuven.be
Geofrey
G
De Visscher
An
A
Lebacq
Lindsay
L
Mesure
Helga
H
Blockx
Ilse
I
Vranken
Ruth
R
Plusquin
Bart
B
Meuris
Marie-Christine
MC
Herregods
Hans
H
Van Oosterwyck
Willem
W
Flameng
D000818:Animals; D001483:Base Sequence; D001705:Bioprosthesis; D002417:Cattle; D054377:Chemokine CXCL12 / Q000378:metabolism; D017931:DNA Primers; D005353:Fibronectins / Q000378:metabolism; D006350:Heart Valve Prosthesis; D008297:Male; D016133:Polymerase Chain Reaction; D051381:Rats; D017208:Rats, Wistar; D019718:Receptors, CXCR4 / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology*
D054377:Chemokine CXCL12; D017931:DNA Primers; D005353:Fibronectins; D019718:Receptors, CXCR4