Accelerated hypertrophic chondrocyte kinetics in GDF-7 deficient murine tibial growth plates
✍ Scribed by Borjana Mikic; Maria P. Ferreira; Todd C. Battaglia; Ernst B. Hunziker
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- English
- Weight
- 227 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0736-0266
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✦ Synopsis
Abstract
The Growth/Differentiation Factors (GDFs) are a subgroup of the Bone Morphogenetic Proteins (BMPs) well known for their role in joint formation and chondrogenesis. Mice deficient in one of these signaling molecules, GDF‐5, have recently been shown to exhibit a decreased rate of endochondral bone growth in the proximal tibia due to a significantly longer hypertrophic phase duration. GDF‐7 is a related family member, which exhibits a high degree of sequence identity with GDF‐5. The purpose of the present study was to determine whether GDF‐7 deficiency also alters the endochondral bone growth rate in mice and, if so, how this is achieved. Stereologic and cell kinetic parameters in proximal tibial growth plates from 5‐week‐old female GDF‐7 −/− mice and wild type control littermates were examined. GDF‐7 deficiency resulted in a statistically significant increase in growth rate (+26%; p = 0.0084) and rate of cell loss at the chondrosseous junction (+25%; p = 0.0217). Cells from GDF‐7 deficient mice also exhibited a significantly shorter hypertrophic phase duration compared to wild type controls (−27%; p = 0.0326). These data demonstrate that, in the absence of GDF‐7, the rate of endochondral bone growth is affected through the modulation of hypertrophic phase duration in growth plate chondrocytes. These findings further support a growing body of evidence implicating the GDFs in the formation, maturation, and maintenance of healthy cartilage. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:986–990, 2008