1. Academic Validation
  2. Gallein increases the fibroblast growth factor 2-elicited osteoprotegerin synthesis in osteoblasts

Gallein increases the fibroblast growth factor 2-elicited osteoprotegerin synthesis in osteoblasts

  • Biochim Biophys Acta Gen Subj. 2024 Aug;1868(8):130635. doi: 10.1016/j.bbagen.2024.130635.
Gen Kuroyanagi 1 Tomoyuki Hioki 2 Rie Matsushima-Nishiwaki 3 Osamu Kozawa 3 Haruhiko Tokuda 4
Affiliations

Affiliations

  • 1 Department of Orthopaedic Surgery, Nagoya City University, Nagoya 467-8601, Japan; Department of Rehabilitation Medicine, Nagoya City University, Nagoya 467-8601, Japan; Department of Pharmacology, Gifu University, Gifu 501-1194, Japan; Department of Metabolic Research, Research Institute, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan. Electronic address: kokuryugen@ymail.ne.jp.
  • 2 Department of Pharmacology, Gifu University, Gifu 501-1194, Japan; Department of Metabolic Research, Research Institute, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan; Department of Dermatology, Kizawa Memorial Hospital, Minokamo, Gifu 505-0034, Japan.
  • 3 Department of Pharmacology, Gifu University, Gifu 501-1194, Japan; Department of Metabolic Research, Research Institute, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan.
  • 4 Department of Pharmacology, Gifu University, Gifu 501-1194, Japan; Department of Metabolic Research, Research Institute, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan; Department of Clinical Laboratory, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan.
Abstract

Gallein is known as an inhibitor of Gβγ subunits, but roles of gallein in bone metabolism have not been reported. Fibroblast Growth Factor 2 (FGF-2) increases angiogenesis and promotes bone regeneration during the early stages of fracture healing. Osteoprotegerin (OPG) secreted by osteoblasts, binds to the receptor activator of nuclear factor-κB (RANK) ligand (RANKL) as a decoy receptor and prevents RANKL from binding to RANK, resulting in the suppression of bone resorption. Our previous report demonstrated that FGF-2 activates the phosphorylation of p38 mitogen-activated protein kinase (MAPK), stress-activated protein kinase/c-Jun N-terminal kinase (JNK), and p44/p42 MAPK in osteoblast-like MC3T3-E1 cells. Additionally, FGF-2-activated phosphorylation of p38 MAPK and JNK but not p44/p42 MAPK is positively involved in OPG synthesis in these cells. This work aimed to investigate the effects of gallein on the FGF-2-elicited OPG synthesis in osteoblast-like MC3T3-E1 cells and the mechanism. Our findings demonstrated that gallein significantly increased the FGF-2-elicited OPG synthesis in MC3T3-E1 cells. By contrast, fluorescein, gallein-like compound that does not bind Gβγ, did not affect the FGF-2-elicited OPG synthesis. Gallein significantly enhanced the FGF-2-induced OPG mRNA expression levels. Gallein did not affect the FGF-2-activated phosphorylation of p38 MAPK and p44/p42 MAPK, but significantly increased the FGF-2-activated phosphorylation of JNK, while fluorescein did not affect JNK phosphorylation. SP600125, a specific JNK Inhibitor, strongly inhibited gallein-induced enhancement of FGF-2-induced OPG synthesis and mRNA expression levels. Our results indicated that gallein increases the FGF-2-induced OPG synthesis due to the JNK activation in the osteoblast.

Keywords

Fibroblast growth factor; Gallein; Osteoblast; Osteoprotegerin.

Figures
Products
  • Cat. No.
    Product Name
    Description
    Target
    Research Area
  • HY-D0254
    ≥98.0%, Gβγ Subunit Inhibitor