Effects of mycophenolate mofetil on key pattern of coronary restenosis: a cascade of in vitro and ex vivo models.
BACKGROUND
Mycophenolate mofetil (MMF), the prodrug of mycophenolic acid (MPA), is a rationally designed immunosuppressive drug. The current study investigates the effect of MMF on key pattern of restenosis in a cascade of in vitro and ex vivo models.


METHODS
Part I of the study investigated in northern blot and cytoflow studies the effect of MMF (50, 100, 150, 200, 250, and 300 microg/mL) on TNF-alpha induced expression of intercellular adhesion molecule 1 (ICAM-1) in human coronary endothelial cells (HCAEC) and human coronary medial smooth muscle cells (HCMSMC). Part II of the study applied a human coronary 3D model of leukocyte attack, the 3DLA-model. HCAEC and HCMSMC were cultured on both sides of a polycarbonate filters, mimicking the internal elastic membrane. Leukocyte attack (LA) was carried out by adding human monocytes (MC) on the endothelial side. The effect of MMF (50 microg/mL) on adhesion and chemotaxis (0.5, 1, 2, 3, 4, 6, and 24 h after LA) and the effect on proliferation of co-cultured HCMSMC (24 h after LA) was studied. In part III of the study a porcine coronary organ culture model of restenosis (POC-model) was used. After ex vivo ballooning MMF (50 microg/mL) was added to the cultures for a period of 1, 2, 3, 4, 5, 6, and 7 days. The effect on reactive cell proliferation and neointimal thickening was studied at day 7 and day 28 after ballooning.


RESULTS
Expression of ICAM-1 in northern blot and cytoflow studies was neither clearly inhibited nor stimulated after administration of MMF in the clinical relevant concentration of 50 microg/mL. In the 3DLA-model 50 microg/mL of MMF caused a significant antiproliferative effect (p < 0.001) in co-cultured HCMSMC but had no effect on MC-adhesion and MC-chemotaxis. In the ex vivo POC-model neighter reactive cell proliferation at day 7 nor neointimal hyperplasia at day 28 were significantly inhibited by MMF (50 microg/mL).


CONCLUSIONS
Thus, the data demonstrate a significant antiproliferative effect of clinical relevant levels of MMF (50 microg/mL) in the 3DLA-model. The antiproliferative effect was a direct antiproliferative effect that was not triggered via reduced expression of ICAM-1 or via an inhibition of MC-adhesion and chemotaxis. Probably due to technical limitations (as e.g. the missing of perfusion) the antiproliferative effect of MMF (50 microg/mL) could not be reproduced in the coronary organ culture model. A cascade of focused in vitro and ex vivo models may help to gather informations on drug effects before large experimental studies are initiated.
Voisard
Rainer
R
Department of Internal Medicine II - Cardiology, Institute of Mikrobiology and Immunology, University of Ulm, Germany. rainer.voisard@uni-ulm.de
Viola
Sandra
S
Kaspar
Verena
V
Weber
Christian M
CM
von Müller
Lutz
L
Baur
Regine
R
Gastrock-Balitsch
Iris
I
Hombach
Vinzenz
V
D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D023903:Coronary Restenosis / Q000188:drug therapy / Q000503:physiopathology; D003331:Coronary Vessels / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D009000:Monocytes / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009173:Mycophenolic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects; D011355:Prodrugs; D013997:Time Factors
D007166:Immunosuppressive Agents; D011355:Prodrugs; D009173:Mycophenolic Acid