Title:
The role of phospholipase d in osteoblasts in response to titanium surfaces
The role of phospholipase d in osteoblasts in response to titanium surfaces
dc.contributor.advisor | Boyan, Barbara D. | |
dc.contributor.author | Fang, Mimi | en_US |
dc.contributor.committeeMember | Eskin, Suzanne | |
dc.contributor.committeeMember | Lobachev, Kirill | |
dc.contributor.committeeMember | Schwartz, Zvi | |
dc.contributor.department | Biomedical Engineering | en_US |
dc.date.accessioned | 2009-01-22T15:37:00Z | |
dc.date.available | 2009-01-22T15:37:00Z | |
dc.date.issued | 2008-11-19 | en_US |
dc.description.abstract | Biomaterial surface properties such as microtopography and energy can change cellular responses at the cell-implant interface. Phospholipase D (PLD) is required for differentiation of osteoblast-like MG63 cells on machined and grit-blasted titanium surfaces. Here, we determined if PLD is also required on microstructured/high-energy substrates and the mechanism involved. shRNAs for human PLD1 and PLD2 were used to silence MG63 cells. Wild-type and PLD1 or PLD1/2 silenced cells were cultured on smooth-pretreatment surfaces (PT); grit-blasted, acid-etched surfaces (SLA); and SLA surfaces modified to have higher surface energy (modSLA). PLD was inhibited with ethanol or activated with 24,25-dihydroxyvitamin-D₃ [24R,25(OH)₂D₃]. As surface roughness/energy increased, PLD mRNA and activity increased, cell number decreased, osteocalcin and osteoprotegerin increased, and protein kinase C (PKC) and alkaline phosphatase specific activities increased. Ethanol inhibited PLD and reduced surface effects on these parameters. There was no effect on these parameters after knockdown of PLD1, but PLD1/2 double knockdown had effects comparable to PLD inhibition. 24R,25(OH)₂D₃increased PLD activity and production of osteocalcin and osteoprotegerin, but decreased cell number on the rough/high-energy surfaces. These results confirm that surface roughness/energy-induced PLD activity is required for osteoblast differentiation and that PLD2 is the main isoform involved in this pathway. Here we showed that PLD is activated by 24R,25(OH)₂D₃ in a surface-dependent manner and inhibition of PLD reduced the effects of surface microstructure/energy on PKC, suggesting that PLD mediates the stimulatory effect of microstructured/high-energy surfaces via PKC-dependent signaling. | en_US |
dc.description.degree | M.S. | en_US |
dc.identifier.uri | http://hdl.handle.net/1853/26462 | |
dc.publisher | Georgia Institute of Technology | en_US |
dc.subject | Osteoblasts | en_US |
dc.subject | Phospholipase D | en_US |
dc.subject | Titanium implants | en_US |
dc.subject | Surface energy | en_US |
dc.subject.lcsh | Biomedical materials | |
dc.subject.lcsh | Surface roughness | |
dc.subject.lcsh | Implants, Artificial Physiological effect | |
dc.subject.lcsh | Phospholipases | |
dc.title | The role of phospholipase d in osteoblasts in response to titanium surfaces | en_US |
dc.type | Text | |
dc.type.genre | Thesis | |
dspace.entity.type | Publication | |
local.contributor.corporatename | Wallace H. Coulter Department of Biomedical Engineering | |
local.contributor.corporatename | College of Engineering | |
relation.isOrgUnitOfPublication | da59be3c-3d0a-41da-91b9-ebe2ecc83b66 | |
relation.isOrgUnitOfPublication | 7c022d60-21d5-497c-b552-95e489a06569 |
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