Ablation of collagen IX and COMP disrupts epiphyseal cartilage architecture.
Chondrodysplasias are a genetically heterogeneous group of skeletal disorders. Mutations in genes coding for cartilage oligomeric matrix protein (COMP), collagen IX and matrilin-3 have been described to cause the autosomal dominantly inherited form of multiple epiphyseal dysplasia (MED). Even though there is clear evidence that these cartilage matrix proteins interact with each other, their exact functions in matrix organisation and bone development still need to be elucidated. We generated a mouse model lacking both collagen IX and COMP to study the potential complementary role of these proteins in skeletal development. Mice deficient in both proteins exhibit shortened and widened long bones as well as an altered bone structure. They display severe growth plate abnormalities with large hypocellular areas in the central parts of the tibia. In addition, chondrocytes in the proliferative and hypertrophic zones do not show their typical columnar arrangement. These phenotypical traits were not observed in mice deficient only in COMP, while mice lacking only collagen IX showed similar growth plate disturbances and shorter and wider tibiae. The contribution of COMP to the phenotype of mice deficient in both collagen IX and COMP appears minor, even though clear differences in the deposition of matrilin-3 were detected.
Blumbach
Katrin
K
Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, D-50931 Cologne, Germany.
Niehoff
Anja
A
Paulsson
Mats
M
Zaucke
Frank
F
D000375:Aging / Q000502:physiology; D000818:Animals; D019521:Body Patterning; D001842:Bone and Bones / Q000002:abnormalities / Q000378:metabolism; D024081:Collagen Type IX / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D006132:Growth Plate / Q000002:abnormalities / Q000196:embryology / Q000378:metabolism*; D064235:Matrilin Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout
D024081:Collagen Type IX; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; C577540:Matn1 protein, mouse; D064235:Matrilin Proteins