Collagen and alkaline phosphatase gene expression during bone morphogenetic protein (BMP)-induced cartilage and bone differentiation.
Endochondral bone formation induced by bone morphogenetic protein (BMP) involves expression of collagen Types I and II and alkaline phosphatase (ALP) genes. Expression of these genes was studied in mice after implantation of BMP. The amount of Type I collagen mRNA increased from Day 3 to Day 7, when mesenchymal cell aggregation was observed. On Day 17, Type I collagen mRNA expression was correlated with an increased number of osteoblasts. Type II collagen mRNA increased from Day 7 and coincided with chondroblast appearance. This increase was suppressed by Day 17, although hypertrophic and degenerative chondrocytes were present. Alkaline phosphatase mRNA increased markedly from Day 7 with the appearance of chondroblasts. The high level of ALP mRNA continued until Day 11, during chondrogenesis. Mineral deposition was first observed roentgenographically on Day 11. Thus, BMP-induced bone formation occurs with the expression of collagen Types I and II and ALP genes.
Sakano
S
S
Department of Orthopaedic Surgery, Nagoya University School of Medicine, Japan.
Murata
Y
Y
Miura
T
T
Iwata
H
H
Sato
K
K
Matsui
N
N
Seo
H
H
D000469:Alkaline Phosphatase / Q000235:genetics*; D000818:Animals; D019485:Bone Morphogenetic Proteins; D001842:Bone and Bones / Q000201:enzymology; D002356:Cartilage / Q000166:cytology / Q000201:enzymology*; D002454:Cell Differentiation; D003094:Collagen / Q000235:genetics*; D015870:Gene Expression; D006133:Growth Substances / Q000502:physiology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008815:Mice, Inbred Strains; D010012:Osteogenesis; D011506:Proteins / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits
D019485:Bone Morphogenetic Proteins; D006133:Growth Substances; D011506:Proteins; D012333:RNA, Messenger; D003094:Collagen; D000469:Alkaline Phosphatase