title: Unphosphorylated heat shock protein 27 suppresses fibroblast growth factor‑2‑stimulated vascular endothelial growth factor release in osteoblasts.
abstract: Heat shock protein 27 (HSP27) also known as heat shock protein β1 (HSPB1) is a member of the family of small heat shock proteins ubiquitously expressed in all tissues. It has previously been demonstrated that HSP27 regulated the synthesis of osteocalcin and interleukin‑6 in osteoblast‑like MC3T3‑E1 cells. In the present study, the effect of HSP27 on basic fibroblast growth factor (FGF‑2)‑stimulated vascular endothelial growth factor (VEGF) synthesis in MC3T3‑E1 cells, was observed. The levels of VEGF release stimulated by FGF‑2 in the HSP27‑overexpressing MC3T3‑E1 cells were significantly lower compared with those in the control cells. In addition, the levels of VEGF release stimulated by FGF-2 in the phosphomimic HSP27-overexpressing cells were significantly higher compared with those in the non‑phosphorylatable HSP27‑overexpressing cells. Furthermore, no significant differences were observed in the FGF‑2‑induced phosphorylation levels of p44/p42 mitogen‑activated protein (MAP) kinase, p38 MAP kinase, stress‑activated protein kinase/c‑Jun N‑terminal kinase (SAPK/JNK) or p70 S6 kinase among the four types of transfected cells. These results suggested that unphosphorylated HSP27 attenuated the FGF‑2‑stimulated VEGF synthesis in osteoblasts.
authors.affiliation: Department of Orthopedic Surgery, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kondo
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Tokuda
authors.forename: Rie
authors.initials: R
authors.lastname: Matsushima-Nishiwaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Kato
authors.forename: Gen
authors.initials: G
authors.lastname: Kuroyanagi
authors.forename: Jun
authors.initials: J
authors.lastname: Mizutani
authors.forename: Muneyoshi
authors.initials: M
authors.lastname: Fukuoka
authors.forename: Ikuo
authors.initials: I
authors.lastname: Wada
authors.forename: Osamu
authors.initials: O
authors.lastname: Kozawa
authors.forename: Takanobu
authors.initials: T
authors.lastname: Otsuka
mesh_terms: D000818:Animals; D002460:Cell Line; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D015870:Gene Expression; D055551:HSP27 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D055551:HSP27 Heat-Shock Proteins; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2