1100 Expression of Pleiotrophin and receptor PTP b/z /Phosphacan in odontoblasts

Friday, March 23, 2012: 3:30 p.m. - 4:45 p.m.
Presentation Type: Poster Session
A. TAMKENATH1, J. AMES2, O. MAMAEVA2, K. STIDHAM3, P. PINERAS4, T. DEUEL4, M. MACDOUGAL2, and H. ERLANDSEN2, 1Periodontology, University of Alabama, Birmimgham, AL, 2University of Alabama at Birmingham, Birmingham, AL, 3University of Alabama, Mt. Olive, AL, 4The Scripps Research Institute, La Jolla, CA
Pleiotrophin (PTN; HB-GAM, OSF-1) is a secreted heparin-binding protein that effects osteoblast differentiation and recruitment. PTN and its receptor (protein tyrosine phosphatase beta/zeta) were found to be required for postnatal bone development (Imai et al. (2009) Bone 44: 785-794 and Schinke et al. (2008) Bone 42: 524-34). PTN deficiency results in a late stage developmental change in bone growth (mostly weight-bearing long bones). This indicates the osteogenic effect of PTN may be linked to mechanical stress in bones and be involved in mediating usage-dependent bone formation. Objectives: Investigate the presence of PTN and its receptor RPTPb/z in mice teeth to determine whether PTN and RPTPb/z plays a role in tooth development and mineralization. Methods: Mouse pulp (MD10D3, MD10A11) and odontoblast (MO6-G3) cell lines were grown and collected for RT-PCR analysis, immunohistochemistry, and Western blot analysis.  Results: PTN (mRNA and protein) was expressed in both epithelial/mesenchymal dental cells at different levels. RT-PCR showed that RPTPb/z was expressed in MO6-G3 odontoblasts, specifically as the long extracellular phosphacan form. Immunohistochemistry revealed PTN expression throughout odontogenesis in the mouse (developmental days E16-PN10).  Conclusions: These studies demonstrate that PTN and Phosphacan are expressed during tooth development. Localization of PTN within the PDL and odontoblasts (mechanio-sensing cells) may indicate that PTN is involved in the production or homeostasis of mineralized tissue. The presence of Phosphacan and its function in odontogenesis is being investigate. Support: NIDCR/1R03DE019497-01A1(HE), NIDCR/T35-HL007473(MM).
This abstract is based on research that was funded entirely or partially by an outside source: NIDCR/T35-HL007473,NIDCR/1RO3DE019497-01A1

Keywords: Extracellular matrix molecules, Hormones and growth factors, Mineralization, Odontoblasts and Oral biology