RRC ID 52056
著者 Takano A, Fukuda T, Shinjo T, Iwashita M, Matsuzaki E, Yamamichi K, Takeshita M, Sanui T, Nishimura F.
タイトル Angiopoietin-like protein 2 is a positive regulator of osteoblast differentiation.
ジャーナル Metabolism
Abstract INTRODUCTION AND AIMS:Several studies have reported that angiopoietin-like protein 2 (Angptl2) is expressed abundantly in adipocytes and is associated with adipose tissue inflammation. In the present study, we found that osteoblasts and mesenchymal stem cells also expressed Angptl2 at high levels. The aim of this study was to understand the role of Angptl2 in osteoblastic cell differentiation.
METHODS:Angptl2 expression was examined during osteoblast and adipocyte differentiation. The role of Angptl2 on cell differentiation and associated signaling was analyzed by gene knockdown using Angptl2 small interfering ribonucleic acid (siRNA).
RESULTS:Angptl2 was highly expressed in MC3T3-E1 cells, ST2 cells and primary osteoblasts, but not in RAW264 cells. Inhibition of Angptl2 expression using siRNA markedly inhibited alkaline phosphatase (ALP) expression and osteoblastic differentiation in MC3T3-E1, ST2 cells and primary osteoblasts. Angptl2 siRNA also inhibited adipocyte differentiation in ST2 cells. Treatment of MC3T3-E1 cells with Angptl2 siRNA led to the down-regulation of the activities of several cell signaling pathways, including extracellular signal-regulated kinase (ERK), Jun amino-terminal kinase (JNK), Akt, and nuclear factor kappa B (NF-κB) signals. It also down-regulated the expression of Osterix, but not that of runt-related transcription factor 2 (Runx2), suggesting that Angptl2 is a positive activator of Osterix and its down-stream signals. Treatment of MC3T3-E1 cells with anti-Angptl2 antibodies suppressed ALP gene expression. In addition, treatment of Angptl2 siRNA-treated cells with culture supernatants of normal MC3T3-E1 cells restored ALP gene expression, indicating that Angptl2 acts in an autocrine manner.
CONCLUSIONS:The results suggest that Angptl2 is an autocrine positive regulator of cell differentiation. Thus, it is suggested that Angptl2 regulates not only adipose tissue metabolism but also bone metabolism.
巻・号 69
ページ 157-170
公開日 2017-4-1
DOI 10.1016/j.metabol.2017.01.006
PII S0026-0495(17)30010-0
PMID 28285646
MeSH Adipocytes / physiology Angiopoietin-Like Protein 2 Angiopoietin-like Proteins Angiopoietins / genetics* Angiopoietins / physiology* Animals Autocrine Communication / genetics Autocrine Communication / physiology Cell Differentiation / genetics* Cell Differentiation / physiology* Cells, Cultured Gene Knockdown Techniques Inflammation / genetics Inflammation / pathology MAP Kinase Signaling System / genetics MAP Kinase Signaling System / physiology Mesenchymal Stem Cells Mice Osteoblasts / physiology* RNA, Small Interfering Signal Transduction / genetics Signal Transduction / physiology
IF 6.159
引用数 8
リソース情報
ヒト・動物細胞 MC3T3-E1(RCB1126) RAW 264(RCB0535) ST2(RCB0224)