BMP-5 deficiency alters chondrocytic activity in the mouse proximal tibial growth plate

• Published in: Bone (New York, N.Y.) Vol. 24; no. 3; pp. 211 - 216
• Main Authors: Bailón-Plaza, A, Lee, A.O, Veson, E.C, Farnum, C.E, van der Meulen, M.C.H
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.03.1999; Elsevier Science
• Subjects: Animals; Biological and medical sciences; Bone Development - physiology; Bone Morphogenetic Protein 5; Bone morphogenetic proteins; Bone Morphogenetic Proteins - deficiency; Bone Morphogenetic Proteins - genetics; Bone Morphogenetic Proteins - physiology; Bromodeoxyuridine - metabolism; Cell Count; Cell Differentiation; Cell Division - physiology; Chondrocytes; Chondrocytes - physiology; Differentiation; Disease Models, Animal; Endochondral ossification; Female; Fundamental and applied biological sciences. Psychology; Growth plate; Growth Plate - cytology; Growth Plate - physiology; Hypertrophy - pathology; Image Processing, Computer-Assisted; Mice; Mice, Knockout; Oxytetracycline; Short ear mice; Skeleton and joints; Space life sciences; Tibia - cytology; Tibia - physiology; Vertebrates: osteoarticular system, musculoskeletal system; Growth plate; Bone morphogenetic proteins; Short ear mice; Differentiation; Endochondral ossification; Chondrocytes; Cell function; Chondrocyte; Rodentia; Exploration; Cell differentiation; Vertebrata; Mammalia; Epiphyseal cartilage; Histopathology; Bone morphogenetic protein; Mouse; Tibia; Animal
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/S8756-3282(98)00171-9

The role of bone morphogenetic protein-5 (BMP-5) in regulating chondrocytic activity during endochondral ossification was examined in the mouse proximal tibial growth plate. Short ear mice homozygous for the SEA/Gn point mutation in the coding region for BMP-5 (King, J. A. et al. Dev Biol 166:112–122; 1994) and heterozygous long ear littermates were examined at 5 and 9 weeks of age (n = 9/group, four groups). Animals were injected with oxytetracycline to estimate the rate of growth and with bromodeoxyuridine to identify proliferative chondrocytes. Age-related changes in chondrocytic stereological and kinetic parameters were compared by image analysis of 1-μm-thick growth plate sections. The number of proliferative chondrocytes did not vary with age in either genotype, but proliferative phase duration increased significantly (∼67%) with age in the long ear mice, whereas no change was detected in the short ear mice. The number of hypertrophic chondrocytes increased significantly (∼27%) in the short ears, whereas this number decreased significantly (∼40%) in the long ears. There was a small, but significant, increase in hypertrophic phase duration (∼45%) in short ear mice, but no change was detected in the long ears. These results indicate that BMP-5 deficiency prevents age-related decelerations in chondrocytic proliferation and initiation of hypertrophic differentiation, suggesting a role of BMP-5 in inhibiting these processes.