Inhibitory effects of mevastatin and a geranylgeranyl transferase I inhibitor (GGTI-2166) on mononuclear osteoclast formation induced by receptor activator of NF kappa B ligand (RANKL) or tumor necrosis factor-alpha (TNF-alpha).
We have previously reported that the statin mevastatin (compactin) reversibly inhibits the fusion of TRAP-positive mononuclear preosteoclasts (pOCs) into multinucleated osteoclasts and disrupts the actin ring in mature osteoclasts through the inhibition of protein prenylation. Protein geranylgeranylation, specifically, is known to be required for pOC fusion and for the function and survival of mature osteoclasts. However, it has not been determined whether protein geranylgeranylation is involved in early differentiation of osteoclasts (pOC formation). The current study shows that statins and the geranylgeranyl transferase I inhibitor GGTI-2166 inhibit the pOC formation induced by RANKL or TNF-alpha in cultures of both mouse marrow-derived macrophage-colony-stimulating factor (M-CSF) dependent monocytes (MD cells) and the mouse monocyte cell line RAW 264.7 (RAW cells). Mevastatin, 0.1-0.6 microM, inhibited the formation of pOCs induced by receptor activator of nuclear factor-kappaB ligand (RANKL) or tumor necrosis factor (TNF-alpha) in both cell cultures. The inhibitory effects of mevastatin were overcome by the addition of mevalonate, farnesyl pyrophosphate or geranylgeranyl pyrophosphate. GGTI-2166 inhibited TRAP activity induced by RANKL or TNF-alpha in both cell cultures and prevented the incorporation of [3H]all-trans geranylgeraniol into prenylated proteins in RAW cells. However, the farnesyl transferase inhibitor FTI-2153 did not inhibit TRAP activity although FTI prevented the incorporation of [14C]mevalonate into farnesylated proteins in RAW cells. Clostridium difficile cytotoxin B (toxin B) inhibited pOC formation induced by RANKL or TNF-alpha in both cell cultures. The inhibitory effects of statins and GGTI-2166 on pOC formation may result from the inhibition of the geranylgeranylation of G-proteins, such as Rho or Rac, suggesting that the geranylgeranylation of these proteins is involved in the early differentiation of progenitor cells into pOCs.
Woo
Je-Tae
JT
Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Feinberg School of Medicine, 303 E. Chicago Avenue, Chicago, IL 60611, USA.
Nakagawa
Hiroshi
H
Krecic
Annette M
AM
Nagai
Kazuo
K
Hamilton
Andrew D
AD
Sebti
Said M
SM
Stern
Paula H
PH
D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis*; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000378:metabolism; D008148:Lovastatin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D051379:Mice; D010010:Osteoclasts / Q000187:drug effects* / Q000378:metabolism; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D008562:Membrane Glycoproteins; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; C505687:Tnfrsf11a protein, mouse; C505689:Tnfsf11 protein, mouse; D014409:Tumor Necrosis Factor-alpha; C012258:mevastatin; D008148:Lovastatin; D019883:Alkyl and Aryl Transferases; C083291:geranylgeranyltransferase type-I