title: In vivo characterization of bone marrow-derived fibroblasts recruited into fibrotic lesions.
abstract: Fibroblasts, which are widely distributed and play a key part in tissue fibrosis, are phenotypically and functionally heterogeneous. Recent studies reported that bone marrow can be a source of tissue fibroblast. In the study reported here, we investigated in vivo characterization of bone marrow-derived fibroblasts recruited into various fibrotic lesions. Mice were engrafted with bone marrow isolated from transgenic mice expressing green fluorescent protein (GFP), and fibrotic lesions were induced by cancer implantation (skin), excisional wounding (skin), and bleomycin administration (lung). A small population of GFP+ fibroblast was found even in nonfibrotic skin (8.7% +/- 4.6%) and lung (8.9% +/- 2.5%). The proportion of GFP+ fibroblasts was significantly increased after cancer implantation(59.7% +/- 16.3%) and excisional wounding (32.2% +/- 4.8%), whereas it was not elevated after bleomycin administration (7.1% +/- 2.4%). Almost all GFP+ fibroblasts in fibrotic lesions expressed type I collagen, suggesting that bone marrow-derived fibroblasts would contribute to tissue fibrosis. GFP+ fibroblasts expressed CD45, Thy-1, and alpha-smooth muscle actin at various proportions. Our results suggested that bone marrow-derived fibroblasts expressed several fibroblastic markers in vivo and could be efficiently recruited into fibrotic lesions in response to injurious stimuli; however, the degree of recruitment frequency might depend on the tissue microenvironment.
authors.affiliation: Pathology Division, National Cancer Center Research Institute East, Kashiwa-City, Chiba, Japan.
authors.forename: Genichiro
authors.initials: G
authors.lastname: Ishii
authors.forename: Takafumi
authors.initials: T
authors.lastname: Sangai
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugiyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Ito
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hasebe
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Endoh
authors.forename: Junji
authors.initials: J
authors.lastname: Magae
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ochiai
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000633:toxicity; D001761:Bleomycin / Q000633:toxicity; D001854:Bone Marrow Cells / Q000166:cytology / Q000502:physiology*; D016026:Bone Marrow Transplantation; D019070:Cell Lineage / Q000502:physiology*; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology*; D005355:Fibrosis / Q000473:pathology / Q000503:physiopathology; D051379:Mice; D018345:Mice, Knockout; D009368:Neoplasm Transplantation / Q000473:pathology / Q000502:physiology; D009374:Neoplasms, Experimental / Q000473:pathology / Q000503:physiopathology; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000503:physiopathology*; D012867:Skin / Q000473:pathology / Q000503:physiopathology; D014945:Wound Healing / Q000502:physiology
chemical_list: D000903:Antibiotics, Antineoplastic; D001761:Bleomycin