Behavior of transplanted bone marrow-derived mesenchymal stem cells in periodontal defects.
BACKGROUND
Recently, there have been an increased number of basic and clinical reports indicating the superior potential of bone marrow-derived mesenchymal stem cells (MSCs) for tissue regeneration. In periodontal treatment, previous animal studies indicated that autotransplantation of bone marrow MSCs into experimental periodontal defects enhanced periodontal tissue regeneration. However, mechanisms for periodontal tissue regeneration with MSCs are still unclear. The purpose of this study was to elucidate the behavior of transplanted MSCs in periodontal defects.


METHODS
Bone marrow MSCs were isolated from beagle dogs, labeled with green fluorescent protein (GFP), and expanded in vitro. The expanded MSCs were mixed with atelocollagen (2% type I collagen) at final concentrations of 2 x 10(7) cells/ml and transplanted into experimental Class III periodontal defects. Localizations of GFP and proliferating cell nuclear antigen (PCNA)-positive cells were evaluated by immunohistochemical analysis.


RESULTS
Four weeks after transplantation, the periodontal defects were almost regenerated with periodontal tissue. Cementoblasts, osteoblasts, osteocytes, and fibroblasts of the regenerated periodontal tissue were positive with GFP. PCNA-positive cells were present in regenerating connective tissue.


CONCLUSIONS
These findings suggest that transplanted mesenchymal stem cells could survive and differentiate into periodontal tissue cells, resulting in enhancement of periodontal tissue regeneration.
Hasegawa
Naohiko
N
Department of Periodontal Medicine, Division of Frontier Medical Science, Hiroshima University, Hiroshima, Japan. nhase@hiroshima-u.ac.jp
Kawaguchi
Hiroyuki
H
Hirachi
Akio
A
Takeda
Katsuhiro
K
Mizuno
Noriyoshi
N
Nishimura
Masahiro
M
Koike
Chika
C
Tsuji
Koichiro
K
Iba
Hideo
H
Kato
Yukio
Y
Kurihara
Hidemi
H
D000539:Alveolar Process / Q000601:surgery*; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D001861:Bone Regeneration / Q000502:physiology; D002417:Cattle; D002454:Cell Differentiation / Q000502:physiology; D004285:Dogs; D005260:Female; D049452:Green Fluorescent Proteins; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D018809:Proliferating Cell Nuclear Antigen
D018809:Proliferating Cell Nuclear Antigen; D049452:Green Fluorescent Proteins