AMP-activated protein kinase regulates PDGF-BB-stimulated interleukin-6 synthesis in osteoblasts: Involvement of mitogen-activated protein kinases

作者：Kato Kenji; Otsuka Takanobu; Kondo Akira; Matsushima Nishiwaki Rie; Natsume Hideo; Kozawa Osamu; Tokuda Haruhiko^*

来源：Life Sciences, 2012, 90(1-2): 71-76.

DOI：10.1016/j.lfs.2011.10.023

• PDGF-BB
• AMPK
• IL-6
• Osteoblast

Aim: We have previously reported that platelet-derived growth factor (PDGF)-BB stimulates synthesis of interleukin-6 (IL-6), a potent bone resorptive agent, in osteoblast-like MC3T3-E1 cells, and that the activation of p44/p42 mitogen-activated protein (MAP) kinase, p38MAP kinase and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) is implicated in the IL-6 synthesis. In the present study,we investigated the involvement of AMP-activated protein kinase (AMPK), a regulator of energy metabolism, in the PDGF-BB-stimulated IL-6 synthesis in MC3T3-E1cells. %26lt;br%26gt;Main methods: The levels of IL-6 were measured by ELISA. The phosphorylation of each protein kinases was analyzed by Western blotting. The mRNA levels of IL-6 were determined by real-time RT-PCR. %26lt;br%26gt;Key findings: PDGF-BB time-dependently induced the phosphorylation of AMPK Compound C. an inhibitor of AMPK, which reduced PDGF-BB-induced acetyl-CoA carboxylase phosphorylation, dose-dependently suppressed the PDGF-BB-stimulated IL-6 release. In addition, the PDGF-BB-stimulated IL-6 release in human osteoblasts was also inhibited by compound C. The mRNA expression of IL-6 induced by PDGF-BB was markedly reduced by compound C. The PDGF-BB-induced phosphorylation of p44/p42 MAP kinase, p38 MAP kinase and SAPK/JNK was inhibited by compound C. %26lt;br%26gt;Significance: These results strongly suggest that AMPK positively regulates PDGF-BB-stimulated IL-6 synthesis via the MAP kinases in osteoblasts.

• 出版日期2012-1-2