Nuclear Factor-κB (NF-κB) p65 Interacts with Stat5b in Growth Plate Chondrocytes and Mediates the Effects of Growth Hormone on Chondrogenesis and on the Expression of Insulin-like Growth Factor-1 and Bone Morphogenetic Protein-2
Shufang Wu, Allison Morrison, Hongzhi Sun and Francesco De Luca
The Journal of biological chemistry, v 286(28), pp 24726-24734
Bone Chondrocyte Growth Factors Growth Hormone Growth Plate NF-κB Transcription Factor Signal Transduction STAT Transcription Factor
Growth hormone (GH) stimulates growth plate chondrogenesis and longitudinal bone growth with its stimulatory effects primarily mediated by insulin-like growth factor-1 (IGF-1) both systemically and locally in the growth plate. It has been shown that the transcription factor Stat5b mediates the GH promoting effect on IGF-1 expression and on chondrogenesis, yet it is not known whether other signaling molecules are activated by GH in growth plate chondrocytes. We have previously demonstrated that nuclear factor-κB p65 is a transcription factor expressed in growth plate chondrocytes where it facilitates chondrogenesis. We have also shown that fibroblasts isolated from a patient with growth failure and a heterozygous mutation of inhibitor-κBα (IκB; component of the nuclear factor-κB (NF-κB) signaling pathway) exhibit GH insensitivity. In this study, we cultured rat metatarsal bones in the presence of GH and/or pyrrolidine dithiocarbamate (PDTC), a known NF-κB inhibitor. The GH-mediated stimulation of metatarsal longitudinal growth and growth plate chondrogenesis was neutralized by PDTC. In cultured chondrocytes isolated from rat metatarsal growth plates, GH induced NF-κB-DNA binding and chondrocyte proliferation and differentiation and prevented chondrocyte apoptosis. The inhibition of NF-κB p65 expression and activity (by NF-κB p65 siRNA and PDTC, respectively) in chondrocytes reversed the GH-mediated effects on chondrocyte proliferation, differentiation, and apoptosis. Lastly, the inhibition of Stat5b expression in chondrocytes prevented the GH promoting effects on NF-κB-DNA binding, whereas the inhibition of NF-κB p65 expression or activity prevented the GH-dependent activation of IGF-1 and bone morphogenetic protein-2 expression.
Nuclear Factor-κB (NF-κB) p65 Interacts with Stat5b in Growth Plate Chondrocytes and Mediates the Effects of Growth Hormone on Chondrogenesis and on the Expression of Insulin-like Growth Factor-1 and Bone Morphogenetic Protein-2
Creators
Shufang Wu - St. Christopher's Hospital for Children
Allison Morrison - St. Christopher's Hospital for Children
Hongzhi Sun - Xi'an Jiaotong University
Francesco De Luca - St. Christopher's Hospital for Children
Publication Details
The Journal of biological chemistry, v 286(28), pp 24726-24734
Publisher
Elsevier
Resource Type
Journal article
Language
English
Academic Unit
Pediatrics; College of Medicine
Web of Science ID
WOS:000292547900023
Scopus ID
2-s2.0-79960124728
Other Identifier
991019168865104721
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