Ubiquitin ligase RNF146 coordinates bone dynamics and energy metabolism
Yoshinori Matsumoto, … , Carsten Bergmann, Robert Rottapel
Yoshinori Matsumoto, … , Carsten Bergmann, Robert Rottapel
Published June 5, 2017
Citation Information: J Clin Invest. 2017;127(7):2612-2625. https://doi.org/10.1172/JCI92233.
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Research Article Bone biology Cell biology Article has an altmetric score of 2

Ubiquitin ligase RNF146 coordinates bone dynamics and energy metabolism

Abstract

Cleidocranial dysplasia (CCD) is an autosomal dominant human disorder characterized by abnormal bone development that is mainly due to defective intramembranous bone formation by osteoblasts. Here, we describe a mouse strain lacking the E3 ubiquitin ligase RNF146 that shows phenotypic similarities to CCD. Loss of RNF146 stabilized its substrate AXIN1, leading to impairment of WNT3a-induced β-catenin activation and reduced Fgf18 expression in osteoblasts. We show that FGF18 induces transcriptional coactivator with PDZ-binding motif (TAZ) expression, which is required for osteoblast proliferation and differentiation through transcriptional enhancer associate domain (TEAD) and runt-related transcription factor 2 (RUNX2) transcription factors, respectively. Finally, we demonstrate that adipogenesis is enhanced in Rnf146–/– mouse embryonic fibroblasts. Moreover, mice with loss of RNF146 within the osteoblast lineage had increased fat stores and were glucose intolerant with severe osteopenia because of defective osteoblastogenesis and subsequent impaired osteocalcin production. These findings indicate that RNF146 is required to coordinate β-catenin signaling within the osteoblast lineage during embryonic and postnatal bone development.

Authors

Yoshinori Matsumoto, Jose La Rose, Melissa Lim, Hibret A. Adissu, Napoleon Law, Xiaohong Mao, Feng Cong, Paula Mera, Gerard Karsenty, David Goltzman, Adele Changoor, Lucia Zhang, Megan Stajkowski, Marc D. Grynpas, Carsten Bergmann, Robert Rottapel

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Figure 3

RNF146 is required for osteoblast differentiation.

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RNF146 is required for osteoblast differentiation. (A) qPCR analysis of ...
(A) qPCR analysis of Rnf146 mRNA expression in primary murine osteoblasts cultured in osteogenic medium for 7–14 days. (B) Whole cell lysates from cells in A were probed with the indicated antibodies for Western blot analysis. (C) Rnf146fl/fl mouse–derived calvarial osteoblasts infected with GFP- or Cre-expressing adenovirus to excise endogenous RNF146 protein were cultured in osteogenic medium and stained with alizarin red S solution. (D–F) qPCR analysis of Col1a1 (D), Alp (E), and osteocalcin (F) mRNA expression in cells in C cultured in osteogenic medium for 3–9 days. (G) Rnf146fl/fl mouse–derived calvarial osteoblasts infected with GFP- or Cre-expressing adenovirus were cultured in serum-free medium in the presence or absence of WNT3a (40 ng/ml). Whole cell lysates were probed with the indicated antibodies for Western blot analysis. Right panels: quantification of Western blot analysis. (H) Luciferase activity from a TOPflash reporter assay in cells in G cultured in serum-free medium in the presence or absence of WNT3a (40 ng/ml). (I) Western blot analysis of cells in G cultured in serum-free medium in the presence or absence of WNT3a (40 ng/ml). n = 3. P values were determined by ANOVA with Tukey-Kramer’s post-hoc test (A, B and G–I) or unpaired t test (D–F). Data are presented as mean ± SEM. *P < 0.05.