Method of cell transplantation promoting the organization of intraarterial thrombus.
BACKGROUND
Endovascular aortic repairs have been developed as less invasive treatments for aortic aneurysms. Some aneurismal cavities, however, remain without organization, causing a re-expansion of the aneurysms. We studied cell transplantation into the aneurismal sac to promote the organization of thrombus for the complete healing of aneurysms.


RESULTS
Skin fibroblasts and skeletal myoblasts were isolated from rats for cell transplantation. An intraarterial thrombus model was made by ligation of the carotid artery. Culture medium (medium group, n=11), collagen gel (gel group, n=11), fibroblasts with collagen gel (F group, n=15), myoblasts with collagen gel (M group, n=12), or mixture of fibroblasts and myoblasts with collagen gel (F+M group, n=14) were injected into the thrombus. After 28 days, histologically, the arterial lumens of the F and M groups were partly filled with fibrous tissues, whereas in the F+M group organization was almost completed and luminal sizes diminished. Immunohistochemical staining demonstrated that alpha-smooth muscle actin-positive cells were more abundantly contained in the organized area of the F+M group than in the other groups. We also analyzed cellular function in vitro with immunofluorescence; coculture of fibroblasts and myoblasts showed that the fraction of alpha-smooth muscle actin-positive fibroblasts increased. This phenomenon accounts for the rapid organization of thrombus in the F+M group in vivo.


CONCLUSIONS
Cell transplantation accelerated thrombus organization. Especially, myoblasts enhanced differentiation of fibroblasts into myofibroblasts, contributing to rapid thrombus organization. Cell transplantation into unorganized spaces seems applicable to endovascular treatment of aneurysms.
Hirano
Koji
K
Department of Thoracic and Cardiovascular Surgery, Mie University School of Medicine, Tsu, Mie 514-8507, Japan.
Shimono
Takatsugu
T
Imanaka-Yoshida
Kyoko
K
Miyamoto
Keiichi
K
Fujinaga
Kazuya
K
Kajimoto
Masaki
M
Miyake
Yoichiro
Y
Nishikawa
Masakatsu
M
Yoshida
Toshimichi
T
Uchida
Atsumasa
A
Shimpo
Hideto
H
Yada
Isao
I
Hirata
Hitoshi
H
D000783:Aneurysm / Q000473:pathology; D000818:Animals; D002340:Carotid Artery Diseases / Q000473:pathology; D002341:Carotid Artery Thrombosis / Q000473:pathology / Q000601:surgery*; D002454:Cell Differentiation; D002478:Cells, Cultured / Q000637:transplantation; D018920:Coculture Techniques; D003094:Collagen / Q000008:administration & dosage; D005347:Fibroblasts / Q000637:transplantation*; D005782:Gels; D007269:Injections, Intra-Arterial; D032342:Muscle Cells / Q000637:transplantation*; D018482:Muscle, Skeletal / Q000166:cytology; D032446:Myoblasts / Q000637:transplantation*; D051381:Rats; D011917:Rats, Inbred Lew; D012867:Skin / Q000166:cytology
D005782:Gels; D003094:Collagen