Enhancement by hepatocyte growth factor of bone and cartilage formation during embryonic mouse mandibular development in vitro.
To elucidate the possible roles of hepatocyte growth factor (HGF) in the early development of mouse mandible, HGF was applied to an organ-culture system with chemically defined media. Mandibular arches microdissected from mouse embryos at the 10th day of gestation were cultured for 10 days with or without HGF, HGF plus HGF-receptor (c-met) antisense oligodeoxyribonucleotide, or HGF plus c-met sense oligodeoxyribonucleotide in the media. The cultured mandibles were then analysed, histologically in serial paraffin sections. In the absence of HGF, the tooth organs of bud stage, Meckel's cartilage and the tongue were formed, whereas only a slight amount of bone tissue was formed in the cultured mandible. The expression of intrinsic HGF and c-met in the cultured mandibles was confirmed by reverse transcriptase-polymerase chain reaction. Furthermore, immunohistochemistry demonstrated that both HGF and c-met were localized in areas of the mesenchymal tissue forming bone and cartilage. With HGF in the medium, the volume of both bone and cartilage increased significantly and dose-dependently. HGF also increased the rate of proliferation of osteogenic cells and chondrocytes. Addition of c-met antisense oligodeoxyribonucleotide partially inhibited the HGF-induced enhancement of bone and cartilage formation, whereas addition of c-met sense oligodeoxyribonucleotide had no effect. These results revealed that exogenous HGF enhances bone and cartilage morphogenesis in the cultured mandibles, suggesting physiological roles for intrinsic HGF in the early development of mouse mandible.
Amano
O
O
Department of Anatomy, School of Medicine, Kanazawa University, Takara-machi, Japan. oamano@med.kanazawa-u.ac.jp
Koshimizu
U
U
Nakamura
T
T
Iseki
S
S
D000818:Animals; D002356:Cartilage / Q000187:drug effects* / Q000196:embryology; D002455:Cell Division / Q000187:drug effects; D019902:Chondrocytes / Q000187:drug effects; D020219:Chondrogenesis / Q000187:drug effects*; D016373:DNA, Antisense; D003724:Dental Arch / Q000187:drug effects / Q000196:embryology; D004305:Dose-Response Relationship, Drug; D018507:Gene Expression Regulation, Developmental; D017228:Hepatocyte Growth Factor / Q000235:genetics / Q000494:pharmacology*; D007150:Immunohistochemistry; D008334:Mandible / Q000187:drug effects* / Q000196:embryology; D008648:Mesoderm / Q000166:cytology; D051379:Mice; D009924:Organ Culture Techniques; D010006:Osteoblasts / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects*; D016133:Polymerase Chain Reaction; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics / Q000494:pharmacology; D014059:Tongue / Q000196:embryology; D014083:Tooth Germ / Q000196:embryology
D016373:DNA, Antisense; D017228:Hepatocyte Growth Factor; D019859:Proto-Oncogene Proteins c-met