Abstract
In order to elucidate the role of β-catenin in hypertrophic cartilage zone of the growth plate, we deleted the β-catenin gene ctnnb1[U+F020]specifically from hypertrophic chondrocytes by mating ctnnb1fl/fl mice with BAC-Col10a1-Cre-deleter mice. Surprisingly, this resulted in a significant reduction of subchondral trabecular bone formation in BACCol10Cre; ctnnb1δ/δ (referred to as Cat-ko) mice, although Cre expression was restricted to hypertrophic chondrocytes. The size of the Col10a1 positive hypertrophic zone was normal, but qRT-PCR revealed reduced expression of Mmp13, and Vegfa in Cat-ko hypertrophic chondrocytes, indicating impaired terminal differentiation. Immunohistological and in situ hybridization analysis revealed the substantial deficiency of collagen I positive mature osteoblasts, but equal levels of osterix-positive cells in the subchondral bone marrow space of Cat-ko mice, indicating that the supply of osteoblast precursor cells was not reduced.The fact that in Cat-ko mice subchondral trabeculae were lacking including their calcified cartilage core indicated a strongly enhanced osteoclast activity. In fact, TRAP staining as well as in situ hybridization analysis of Mmp9 expression revealed denser occupation of the cartilage erosion zone with enlarged osteoclasts as compared to the control growth plate, suggesting increased RANKL or reduced osteoprotegerin (Opg) activity in this zone. This notion was confirmed by qRT-PCR analysis of mRNA extracted from cultured hypertrophic chondrocytes or from whole epiphyses, showing increased Rankl mRNA levels in Cat-ko as compared to control chondrocytes, whereas changes in OPG levels were not significant. These results indicate that β-catenin levels in hypertrophic chondrocytes play a key role in regulating osteoclast activity and trabecular bone formation at the cartilage-bone interface by controlling RANKL expression in hypertrophic chondrocytes.
| Original language | English |
|---|---|
| Pages (from-to) | 102-112 |
| Number of pages | 11 |
| Journal | Bone |
| Volume | 55 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jul 2013 |
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Keywords
- Col10Cre
- Endochondral ossification
- Osteoclasts
- Osterix
- RANKL
- Spongiosa
ASJC Scopus subject areas
- Physiology
- Endocrinology, Diabetes and Metabolism
- Histology
Cite this
Deletion of beta catenin in hypertrophic growth plate chondrocytes impairs trabecular bone formation. / Golovchenko, Svitlana; Hattori, Takako; Hartmann, Christine; Gebhardt, Matthias; Gebhard, Sonja; Hess, Andreas; Pausch, Friederike; Schlund, Britta; Von der Mark, Klaus.
In: Bone, Vol. 55, No. 1, 07.2013, p. 102-112.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Deletion of beta catenin in hypertrophic growth plate chondrocytes impairs trabecular bone formation
AU - Golovchenko, Svitlana
AU - Hattori, Takako
AU - Hartmann, Christine
AU - Gebhardt, Matthias
AU - Gebhard, Sonja
AU - Hess, Andreas
AU - Pausch, Friederike
AU - Schlund, Britta
AU - Von der Mark, Klaus
PY - 2013/7
Y1 - 2013/7
N2 - In order to elucidate the role of β-catenin in hypertrophic cartilage zone of the growth plate, we deleted the β-catenin gene ctnnb1[U+F020]specifically from hypertrophic chondrocytes by mating ctnnb1fl/fl mice with BAC-Col10a1-Cre-deleter mice. Surprisingly, this resulted in a significant reduction of subchondral trabecular bone formation in BACCol10Cre; ctnnb1δ/δ (referred to as Cat-ko) mice, although Cre expression was restricted to hypertrophic chondrocytes. The size of the Col10a1 positive hypertrophic zone was normal, but qRT-PCR revealed reduced expression of Mmp13, and Vegfa in Cat-ko hypertrophic chondrocytes, indicating impaired terminal differentiation. Immunohistological and in situ hybridization analysis revealed the substantial deficiency of collagen I positive mature osteoblasts, but equal levels of osterix-positive cells in the subchondral bone marrow space of Cat-ko mice, indicating that the supply of osteoblast precursor cells was not reduced.The fact that in Cat-ko mice subchondral trabeculae were lacking including their calcified cartilage core indicated a strongly enhanced osteoclast activity. In fact, TRAP staining as well as in situ hybridization analysis of Mmp9 expression revealed denser occupation of the cartilage erosion zone with enlarged osteoclasts as compared to the control growth plate, suggesting increased RANKL or reduced osteoprotegerin (Opg) activity in this zone. This notion was confirmed by qRT-PCR analysis of mRNA extracted from cultured hypertrophic chondrocytes or from whole epiphyses, showing increased Rankl mRNA levels in Cat-ko as compared to control chondrocytes, whereas changes in OPG levels were not significant. These results indicate that β-catenin levels in hypertrophic chondrocytes play a key role in regulating osteoclast activity and trabecular bone formation at the cartilage-bone interface by controlling RANKL expression in hypertrophic chondrocytes.
AB - In order to elucidate the role of β-catenin in hypertrophic cartilage zone of the growth plate, we deleted the β-catenin gene ctnnb1[U+F020]specifically from hypertrophic chondrocytes by mating ctnnb1fl/fl mice with BAC-Col10a1-Cre-deleter mice. Surprisingly, this resulted in a significant reduction of subchondral trabecular bone formation in BACCol10Cre; ctnnb1δ/δ (referred to as Cat-ko) mice, although Cre expression was restricted to hypertrophic chondrocytes. The size of the Col10a1 positive hypertrophic zone was normal, but qRT-PCR revealed reduced expression of Mmp13, and Vegfa in Cat-ko hypertrophic chondrocytes, indicating impaired terminal differentiation. Immunohistological and in situ hybridization analysis revealed the substantial deficiency of collagen I positive mature osteoblasts, but equal levels of osterix-positive cells in the subchondral bone marrow space of Cat-ko mice, indicating that the supply of osteoblast precursor cells was not reduced.The fact that in Cat-ko mice subchondral trabeculae were lacking including their calcified cartilage core indicated a strongly enhanced osteoclast activity. In fact, TRAP staining as well as in situ hybridization analysis of Mmp9 expression revealed denser occupation of the cartilage erosion zone with enlarged osteoclasts as compared to the control growth plate, suggesting increased RANKL or reduced osteoprotegerin (Opg) activity in this zone. This notion was confirmed by qRT-PCR analysis of mRNA extracted from cultured hypertrophic chondrocytes or from whole epiphyses, showing increased Rankl mRNA levels in Cat-ko as compared to control chondrocytes, whereas changes in OPG levels were not significant. These results indicate that β-catenin levels in hypertrophic chondrocytes play a key role in regulating osteoclast activity and trabecular bone formation at the cartilage-bone interface by controlling RANKL expression in hypertrophic chondrocytes.
KW - Col10Cre
KW - Endochondral ossification
KW - Osteoclasts
KW - Osterix
KW - RANKL
KW - Spongiosa
UR - http://www.scopus.com/inward/record.url?scp=84877055618&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84877055618&partnerID=8YFLogxK
U2 - 10.1016/j.bone.2013.03.019
DO - 10.1016/j.bone.2013.03.019
M3 - Article
C2 - 23567158
AN - SCOPUS:84877055618
VL - 55
SP - 102
EP - 112
JO - Bone
JF - Bone
SN - 8756-3282
IS - 1
ER -