| 0354 Integrins Expression regulated by Surface Roughness and 1,25(OH)2D3 in Osteoblast | ||
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P. RAZ1, L. WANG2, J. TURNER2, B.D. BOYAN2, and Z. SCHWARTZ1, 1 Hebrew University, Jerusalem, Israel, 2 Georgia Institute of Technology, Atlanta, USA Surface topography is an important factor in modulating cell behavior at the implant/bone interface. In vitro cultures of MG-63 ,osteoblast like cells, on rough surfaces will increase their osteoblastic phenotype. Integrins are a family of hetrodimeric receptors that act as outside-in and inside-out signals. Integrin abound in bone α2β1 α5β1 αvβ3 and are receptors for collagen, fibronectin and vitronectin, respectively.Objective: To determine whether integrins expression is regulated by surface roughness and if this effect is modulated by 1,25(OH)2D3 and depended on culture duration . Methods: MG-63 cell line was cultured on different titanium (Ti) disks: (PT smooth Ra=0.6µm, SLA rough Ra=4-5µm, TPS rough Ra=6-7µm) and on plastic surface as control with or without 10-8-10-9 M 1,25(OH)2D3. mRNA expression of integrins and differentiation markers were relatively quantified by real-time PCR after 4,6,8 days. Results: Osteocalcin expression was significantly increased on rough surface when compared to smooth surface and plastic cultures. 10-8M 1,25(OH)2D3addition had a minor effect on plastic with significant synergistic effect on rough surface cultures. The effect was found after 4 and 6 days but was reduced significantly in all four groups after 8 days. α2 and β1 expression increased significantly on Ti rough surface compared to control smooth surface and was further increased when 1,25(OH)2D3was added. This effect was consistent over time but was more pronounced at day 8. α5 levels were significantly inhibited on Ti surfaces .1,25(OH)2D3inhibited á5 expression on plastic whereas on Ti rough surface the inhibitory effect of surface was abolished. αv levels were reduced in response to 1,25(OH)2D3on Ti surfaces and on plastic significantly after 6 and 8 days. β3 expression level was not sensitive to surface substrate neither to time of culture nor 1,25(OH)2D3treatment. Conclusion: Integrins expression pattern is modulated by surface roughness and by 1,25(OH)2D3and is time depended. | ||
| Seq #35 - Implantology Research 4:00 PM-6:00 PM, Friday, 27 August 2004 Crowne Plaza Hotel AVSA I | ||
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