Mechanism of prostaglandin E2-stimulated heat shock protein 27 induction in osteoblast-like MC3T3-E1 cells.
We investigated the effect of prostaglandin E2 (PGE2) on the induction of heat shock protein 27 (HSP27) and HSP70, and the mechanism behind the induction in osteoblast-like MC3T3-E1 cells. PGE2 time-dependently increased the level of HSP27 without affecting the level of HSP70. PGE2 stimulated the accumulation of HSP27 dose-dependently in the range between 10 nM and 10 microM. PGE2 stimulated the increase in the level of the mRNA for HSP27. Staurosporine and calphostin C, inhibitors of protein kinase C (PKC), suppressed the PGE2-induced HSP27 accumulation. The effect of PGE2 on HSP27 accumulation was reduced in the PKC down-regulated cells. BAPTA/AM, a chelator of intracellular Ca2+, or TMB-8, an inhibitor of intracellular Ca2+ mobilization, reduced the accumulation of HSP27 induced by PGE2. Dibutyryl cAMP had little effect on the basal level of HSP27. PGE2 induced the phosphorylation of both p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase. PD98059 and U-0126, inhibitors of the upstream kinase of p44/p42 MAP kinase, reduced the accumulation of HSP27 induced by PGE2. SB203580, a specific inhibitor of p38 MAP kinase, suppressed the HSP27 accumulation induced by PGE2. U-73122, an inhibitor of phospholipase C, and calphostin C reduced the PGE2-induced phosphorylation of both p44/p42 MAP kinase and p38 MAP kinase. These results indicate that PGE2 stimulates the induction of HSP27 through PKC-dependent activations of both p44/p42 MAP kinase and p38 MAP kinase in osteoblasts.
Tokuda
H
H
Department of Internal Medicine, Chubu National Hospital: National Institute for Longevity Sciences, Obu, Aichi 474-8511, Japan.
Kozawa
O
O
Niwa
M
M
Matsuno
H
H
Kato
K
K
Uematsu
T
T
D000704:Analysis of Variance; D000818:Animals; D002070:Butadienes / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002460:Cell Line; D002614:Chelating Agents / Q000494:pharmacology; D015232:Dinoprostone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins; D007093:Imidazoles / Q000494:pharmacology; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018832:Molecular Chaperones; D009281:Naphthalenes / Q000037:antagonists & inhibitors / Q000494:pharmacology; D009363:Neoplasm Proteins / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D019311:Staurosporine / Q000494:pharmacology; D013268:Stimulation, Chemical; D013997:Time Factors; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors; D048051:p38 Mitogen-Activated Protein Kinases
D002070:Butadienes; D002121:Calcium Channel Blockers; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D004963:Estrenes; D005419:Flavonoids; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C486113:Hsbp1 protein, mouse; D007093:Imidazoles; D018832:Molecular Chaperones; D009281:Naphthalenes; D009363:Neoplasm Proteins; D009570:Nitriles; D011725:Pyridines; D011760:Pyrrolidinones; C113580:U 0126; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D004533:Egtazic Acid; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D005707:Gallic Acid; D011493:Protein Kinase C; D019950:Mitogen-Activated Protein Kinase 1; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D010738:Type C Phospholipases; D019311:Staurosporine; C058819:calphostin C; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D015232:Dinoprostone; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D002118:Calcium