title: Titanium surface roughness accelerates RANKL-dependent differentiation in the osteoclast precursor cell line, RAW264.7.
abstract: The present study was a molecular analysis of the initial differentiation of osteoclast precursor RAW264.7 cells on titanium specimens. RAW264.7 cell line was cultured on titanium specimens of which the surfaces were finished by wet grinding with 2000-, 1200-, 600-, or 180-grit waterproof abrasive paper. Total RNA was extracted from cells cultured in the presence or absence of Receptor Activator of NF-kappaB Ligand (RANKL), prior to cDNA synthesis for real-time quantitative reverse transcriptase-polymerase chain reaction analysis. Titanium surfaces initially enhanced the expression of osteoclast differentiation markers including tartrate-resistant acid phosphatase and cathepsin K in RAW264.7 cells cultured with RANKL stimulation, in a roughness-dependent manner. The mRNA expressions of both RANKL receptor, RANK, and its adapter protein TNF receptor-associated factor 6 (TRAF6) increased when RAW264.7 cells were cultured on titanium specimens with roughened surfaces, as compared with that of control specimen with a polished surface. These results, taken together, suggested that titanium surface roughness facilitated osteoclast differentiation through the activation of the RANK-TRAF6 signaling network.
authors.affiliation: Department of Medical Design and Engineering, Division of Oral Health Engineering, Institute for Oral Health Science, Hiroshima University Faculty of Dentistry, 1-2-3 Kasumi Minami-ku, Hiroshima 734-8553, Japan. seicho@hiroshima-u.ac.jp
authors.forename: Seicho
authors.initials: S
authors.lastname: Makihira
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Mine
authors.forename: Eduardo
authors.initials: E
authors.lastname: Kosaka
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nikawa
mesh_terms: D000135:Acid Phosphatase / Q000096:biosynthesis; D000818:Animals; D056657:Cathepsin K; D002403:Cathepsins / Q000096:biosynthesis; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D015870:Gene Expression; D007527:Isoenzymes / Q000096:biosynthesis; D051379:Mice; D010010:Osteoclasts / Q000502:physiology*; D053245:RANK Ligand / Q000502:physiology*; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013499:Surface Properties; D048029:TNF Receptor-Associated Factor 6 / Q000096:biosynthesis; D000071681:Tartrate-Resistant Acid Phosphatase; D014025:Titanium
chemical_list: D007527:Isoenzymes; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D048029:TNF Receptor-Associated Factor 6; D014025:Titanium; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D002403:Cathepsins; D056657:Cathepsin K; C534132:Ctsk protein, mouse