TY - JOUR
T1 - 1α,25(OH)2D3 Regulation of integrin expression is substrate dependent
AU - Raz, P.
AU - Lohmann, C. H.
AU - Turner, J.
AU - Wang, L.
AU - Poythress, N.
AU - Blanchard, C.
AU - Boyan, B. D.
AU - Schwartz, Z.
PY - 2004/11/1
Y1 - 2004/11/1
N2 - Osteoblasts are attachment-dependent cells that interact with their surface through integrin-mediated mechanisms. Their differentiation is regulated by 1,25-dihydroxyvitamin D3 [1α,25(OH)2D3] and is affected by substrate chemistry and microtopography, suggesting that 1α,25(OH)2D3 may regulate integrin expression in a surface-specific manner. To test this hypothesis, osteoblast-like human MG63 cells were grown on tissue culture plastic and on grit-blasted and acid-etched titanium disks with a complex microtopography to induce osteoblast differentiation. Expression of α2, α5, αv, β1, and β3 integrals were quantified by real-time polymerase chain reaction (PCR) as a function of time in culture and treatment with 1α,25(OH)2D3. Results were correlated with expression of osteocalcin, a marker of a differentiated osteoblast. Osteocalcin mRNA increased with time and 1α,25(OH) 2D3 treatment and these changes were greater in cultures on the titanium disks. Integrin expression varied with time in culture and this was also surface dependent. At each time point, β1 and α2 mRNAs were greater on titanium than on plastic, whereas α5 expression was reduced and αv, β3 expression was unaffected. 1α,25(OH)2D 3 increased β1 mRNA on both surfaces at all time points, but it increased α2 expression only in 8-d cultures. 1α,25(OH)2D3 caused reduced α5 expression only in cultures grown on plastic for 8 d, and had no effect on either αv or β3 expression regardless of surface. These results show that integrin expression in human osteoblast-like cells is differentially modulated by 1α,25(OH)2D3 in a time-dependent manner that is sensitive to the surface on which the cells are grown.
AB - Osteoblasts are attachment-dependent cells that interact with their surface through integrin-mediated mechanisms. Their differentiation is regulated by 1,25-dihydroxyvitamin D3 [1α,25(OH)2D3] and is affected by substrate chemistry and microtopography, suggesting that 1α,25(OH)2D3 may regulate integrin expression in a surface-specific manner. To test this hypothesis, osteoblast-like human MG63 cells were grown on tissue culture plastic and on grit-blasted and acid-etched titanium disks with a complex microtopography to induce osteoblast differentiation. Expression of α2, α5, αv, β1, and β3 integrals were quantified by real-time polymerase chain reaction (PCR) as a function of time in culture and treatment with 1α,25(OH)2D3. Results were correlated with expression of osteocalcin, a marker of a differentiated osteoblast. Osteocalcin mRNA increased with time and 1α,25(OH) 2D3 treatment and these changes were greater in cultures on the titanium disks. Integrin expression varied with time in culture and this was also surface dependent. At each time point, β1 and α2 mRNAs were greater on titanium than on plastic, whereas α5 expression was reduced and αv, β3 expression was unaffected. 1α,25(OH)2D 3 increased β1 mRNA on both surfaces at all time points, but it increased α2 expression only in 8-d cultures. 1α,25(OH)2D3 caused reduced α5 expression only in cultures grown on plastic for 8 d, and had no effect on either αv or β3 expression regardless of surface. These results show that integrin expression in human osteoblast-like cells is differentially modulated by 1α,25(OH)2D3 in a time-dependent manner that is sensitive to the surface on which the cells are grown.
KW - 1α,25(OH)D
KW - Integrins
KW - Osteoblasts
KW - Osteocalcin
KW - Real-time polymerase chain reaction
KW - Substrate surface
KW - Titanium
UR - http://www.scopus.com/inward/record.url?scp=5444229328&partnerID=8YFLogxK
U2 - 10.1002/jbm.a.30134
DO - 10.1002/jbm.a.30134
M3 - מאמר
C2 - 15386491
AN - SCOPUS:5444229328
VL - 71
SP - 217
EP - 225
JO - Journal of Biomedical Materials Research - Part A
JF - Journal of Biomedical Materials Research - Part A
SN - 1549-3296
IS - 2
ER -