Antisense basic fibroblast growth factor alters the time course of mitogen-activated protein kinase in arterialized vein graft remodeling.
OBJECTIVE
Neointimal hyperplasia (NIH) is complete by 3 weeks in rabbit vein grafts implanted into the arterial circulation. Activation of the mitogen-activated protein kinase (MAPK) family of protein kinases is thought to be critical in remodeling events such as cellular proliferation, differentiation, and migration, as found in NIH. We previously demonstrated that antisense basic fibroblast growth factor (ASbFGF) inhibited the synthesis of basic fibroblast growth factor (bFGF) in the balloon injury model of NIH. We examined the effect of ASbFGF on NIH and the time course of MAPK, extracellular signal-regulated kinase (ERK) 1/2, c-Jun N-terminal protein kinase (JNK), and p38 kinase activation in arterialized vein grafts.


METHODS
Carotid interposition of a vein bypass graft was performed in 75 New Zealand White rabbits. Segments of the external jugular vein were transfected with a replication-deficient adenovirus containing the messenger RNA sequence for rat ASbFGF at 1 x 10(10) plaque-forming units per milliliter; control animals were given phosphate-buffered saline solution (PBS) alone. Rabbits were killed at 30 minutes, 4 days, 7 days, and 21 days (n = 8). Four grafts in each group were fixed with formalin and embedded in paraffin, then processed with elastin-collagen and hematoxylin-eosin stains. The other four grafts were individually frozen, and total protein was extracted. Phosphorylation of MAPK, ERK1/2, JNK, and p38, was determined with Western blot analysis and immunohistochemistry. Groups were compared with analysis of variance.


RESULTS
The thickness of neointima in the PBS group and the ASbFGF group at 21 days was 60.2 +/- 2.1 and 39.4 +/- 2.1 microm, respectively (P <.01). In both the control and ASbFGF groups, all 3 MAPKs demonstrated activation compared with preimplantation levels. However, when compared with the PBS group the ASbFGF group showed greater than 33% inhibition of all three MAPKs by day 4 and day 7 (P <.05), but no significant difference in any MAPK activation by day 21 (P >.05, all groups). Cells staining positive for activated MAPK were found in the neointima and adventitia of vein grafts in both the PBS and ASbFGF groups.


CONCLUSIONS
MAPKs are activated during the first week after vein graft implantation. Grafts treated with ASbFGF demonstrated reduced MAPK activation and less neointimal thickening. These results suggest that the process of vein graft adaptation to the arterial circulation, and subsequent NIH, may depend on basic fibroblast growth factor activity, which is mediated, at least in part, by a MAPK-dependent mechanism.
Yamashita
Akimasa
A
Section of Vascular Surgery, Yale University School of Medicine, New Haven and VA Connecticut Healthcare Systems, West Haven, CT, USA.
Hanna
Abigail K
AK
Hirata
Satoshi
S
Dardik
Alan
A
Sumpio
Bauer E
BE
D000818:Animals; D001807:Blood Vessel Prosthesis; D002468:Cell Physiological Phenomena; D004730:Endothelium, Vascular / Q000473:pathology* / Q000502:physiology*; D005346:Fibroblast Growth Factors; D006965:Hyperplasia; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology*; D023421:Models, Animal; D011506:Proteins / Q000502:physiology*; D016372:RNA, Antisense / Q000502:physiology*; D011817:Rabbits; D012038:Regeneration / Q000502:physiology; D013997:Time Factors; D014162:Transfection; D014680:Veins / Q000473:pathology* / Q000502:physiology* / Q000637:transplantation; D048051:p38 Mitogen-Activated Protein Kinases
D011506:Proteins; D016372:RNA, Antisense; C108111:fibroblast growth factor 13; D005346:Fibroblast Growth Factors; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases