title: Cardiomyocyte regeneration from circulating bone marrow cells in mice.
abstract: We investigated the role of circulating bone marrow cells (BMC) in cardiomyocyte regeneration. BMC, isolated from transgenic mice expressing enhanced green fluorescent protein (GFP), were transplanted into lethally irradiated C57BL6 mice. Five weeks after bone marrow transplantation (BMT), flow cytometric analysis for GFP-positive cells confirmed reconstitution of transplanted bone marrow. Bone marrow transplant mice subsequently underwent left coronary artery ligation (myocardial infarction) or sham-operation, and were killed at 1 mo or 3 mo after operation. Infarct size was similar in bone marrow transplant mice at 1 mo (47.1 +/- 5.9%) and at 3 mo (45.3 +/- 7.8%), and echocardiography at 2 and 8 wk revealed decreasing left ventricular function. In infarcted heart, GFP-positive cells that expressed desmin and troponin T-C were identified by confocal microscopy. GFP and troponin T-C double-positive cells were predominantly in the peri-infarcted region (1 mo, 365 +/- 45 cells/50 sections; 3 mo: 458 +/- 100 cells/50 sections; p < 0.05 versus noninfarct, infarct, and sham-operated regions). Furthermore, BMC mobilization and differentiation into cardiomyocytes was found to be complete within 1 mo after myocardial infarction. These results demonstrate that circulating BMC undergo mobilization and differentiation in cardiac cells after myocardial infarction. Future studies are required to determine the molecular signaling mechanisms responsible for this phenomenon.
authors.affiliation: Department of Pediatrics, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan. riosato@win.emial.ne.jp
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kuramochi
authors.forename: Ryuji
authors.initials: R
authors.lastname: Fukazawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Migita
authors.forename: Jun
authors.initials: J
authors.lastname: Hayakawa
authors.forename: Mari
authors.initials: M
authors.lastname: Hayashida
authors.forename: Yohko
authors.initials: Y
authors.lastname: Uchikoba
authors.forename: Daichi
authors.initials: D
authors.lastname: Fukumi
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimada
authors.forename: Shunichi
authors.initials: S
authors.lastname: Ogawa
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism*; D016026:Bone Marrow Transplantation; D004452:Echocardiography; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009203:Myocardial Infarction; D009206:Myocardium / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D032383:Myocytes, Cardiac / Q000166:cytology / Q000502:physiology*; D012038:Regeneration / Q000502:physiology*
chemical_list: D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins