An in vitro model of pericardial tissue healing.
BACKGROUND
A previous study in our laboratory showed that a flap of fresh autologous pericardium bisecting the aorta of sheep retracted and became fibrotic. Histologic analyses suggested that activated cells within the pericardium contributed to the retraction of the implant. Here we report the development of an in vitro model to investigate the effects of serum on cellular proliferation and cell-mediated tissue contraction.


METHODS
Sections of living and ethanol-treated sheep pericardium were incubated with 0.5%, 5%, 10%, 20%, and 50% serum in medium for up to 8 days and evaluated for cellular proliferation and tissue contraction. These serum-stimulated events were further evaluated in the presence of Mitomycin C, Cytochalasin B and D, Aphidicolin, AraC, and Cycloheximide.


RESULTS
Cellular proliferation and cell-mediated tissue contraction were induced by serum in a dose-dependent manner. Expression of PCNA was suppressed in the presence of Cytochalasin B, Cytochalasin D, Aphidicolin, and AraC. Tissue contraction was prevented by Cycloheximide. Mitomycin C inhibited both proliferation and tissue contraction. Ethanol-treated tissue, which was absent of living cells, did not respond to stimulation with serum.


CONCLUSIONS
An in vitro model was developed to study the responses of cells within pericardial tissues to stimulation by serum. In this model, serum induced cellular proliferation and tissue contraction. Different chemical inhibitors independently modulated these serum-stimulated events. Pre-existing cells within pericardial tissues might respond to stimulus through differential pathways. This model may help to develop methods to make autologous pericardium a clinically useful biomaterial.
Marchion
Douglas C
DC
The International Heart Institute of Montana Foundation, 554 West Broadway, Missoula, MT 59802-4008, USA.
Pfau
Jean C
JC
Weber
Patricia A
PA
Grobe
Albert C
AC
Duran
Carlos M G
CM
Cheung
David T
DT
D000818:Animals; D001672:Biocompatible Materials; D002455:Cell Division; D003470:Culture Media; D000431:Ethanol; D066298:In Vitro Techniques; D008422:Materials Testing; D008954:Models, Biological; D010496:Pericardium / Q000033:anatomy & histology / Q000502:physiology / Q000637:transplantation*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D012756:Sheep; D014182:Transplantation, Autologous; D014945:Wound Healing / Q000502:physiology
D001672:Biocompatible Materials; D003470:Culture Media; D018809:Proliferating Cell Nuclear Antigen; D000431:Ethanol