Bioactive peptides function effectively with a minimal amount compared to proteins. Recently SPARC related modular calcium binding 1 (SMOC1) has been implicated in regulating osteoblast differentiation and limb and eye development. In this study we synthesized a peptide covering 16 amino acids derived from the extracellular calcium binding (EC) domain of SMOC1, and its effects on proliferation and osteoblast differentiation of human bone marrow mesenchymal stem cells were examined. Treatment of SMOC1 peptide did not modulate proliferation of BMSCs. However, mineralization of BMSCs was significantly increased with a dose dependent manner. Consistently expression of osteoblast differentiation marker genes including type 1 collagen and osteocalcin was also dose dependently increased. Taken together, these results suggest that peptide derived from the EC domain of SMOC1 recapitulates at least partially osteogenic function of SMOC1.

The central granular cell odontogenic tumor is a rare benign odontogenic neoplasm of uncertain hisotogenesis characterized by varying amounts of eosinophilic granular cells and apparently inactive odontogenic epithelium with variable presence of calcified tissue. We present a case of central granular cell odontogenic tumor involving the maxilla of 35-year-old man with immunohistochemical characterization of granular cells. In microscopic view, the granular cells densely packed in sheets and lobules with abundant eosinophilic, granular cytoplasm and eccentric round-to-ovoid nuclei revealed immunoreactivity for vimentin, α1-antitrysin and CD68, and NSE but not for cytokeratin and S-100 protein while the interspersed odontogenic epithelial cells were positive for cytokeratin only. Granular cells also revealed strong PAS staining. Numerous concentric structured round to ovoid calcified aggregates were also noted. The lesion was treated with excision without recurrence for 8 years. Our immuohistochemical staining findings also suggest that the granular cells of central granular cell odontogenic tumor are mesenchymal in origin with possible histiocytic differentiation

Previous ly we have s hown that fï brob last• growth factor-2 (FGF-2) and dexamethasone (Dex) in combination strongly stimulate both p l 이 i fe rati o n a nd differe nt iation of mesenchymal stem cells (MSCs) into osteoblasts and adipocytes, In the present s tudy we invesL igaLed whether inhibition 01' FGF-2 and Dex-induced adipogenic differentiation of bone marrow derived s Lem cells (BMSCs) by GW9662, an antagoni s t of proxisome proliferators-activated receptol γ (PPARy) which plays a key role in ad ipogenic differentiation , enhances proliferation and osteoblastic differentiation of BMSCs Proliferation 01' BMSCs t reated wi 네 FGF-2 a nd Dex was further increased by GW9662 up to 9,7, 10,6, and 7,2% at 3, 5, and 7 days of cul Lu re , Expansion of BMSCs with FGF-2, Dex and GW9662 followed by osteoblastic different iation showed that osteoblas tic differentiation 01' BMSCs was in creased by 37 % (p=O, 01) compared to those expanded with FGF-2 and Dex, ln contrast , ad i pogenic di fferenti a tion of FGF-2 and Dex-expanded BMSCs was substantially reduced to 14% (p=O, 036) by GW9662, Taken toget her , these resul ts demonstrate that FGF-2 and Dex in combination with GW9662 f ur t her stimu late proliferation 01' BMSCs and those cells expanded with these factors acquire enhanced potentiaIs to be dif ferentiated i n to osteoblas ts

As a pa rt 0 1' the effort to develop a suitable scaffold for tissue-engineered bone regene ration, we modified calcium metaphosphate(CMP) ce ramic with 5 mol% Na20 or K20 to improve t he biodegradability and evaluated their effi ciency as a biodegr adable scaffold for ti ssue-engineered bone regeneration. The macroporous αiIP ceramic blocks incor porated with 5 mol% Na20 or K20 were prepa recl to have average pore size of 250 um in an inte rconnectecl framework structure The influ e nce of inco r pora tecl 5 mol% Na20 or K20 on cytotoxicity‘ cellular attachmont and t heir clifferentiation was evaluated by in vit ro analyzing sys tern. res pectively. The bioclegradability, histocompatibility, and osteogenic effect by cell-scaffolcl co nstruc ts were evalua ted by im plantation of them into subcutaneous pouches of SD-rats 0 1' SCID ITllce The incorporation of 5 mol% Na20 or K20 causecl clecrease of compressive strength without improving of biodegr adabili ty . The moclifi ed scaffolcls revea led no cy totoxic and excell ent biocompatability but osteogneic effect was recluced compa red to pure CMP ce ramic porous blocks . These res ul Ls s ugge::;t tha t the incorporation of 5 mol% Na20 0 1' K20 into pure CMP is not effective for improv ing effï ciency 0 1' scaffolcls fo1' tissue-engineered bone regeneration in terms of bioclegradabi li ty‘ physical s trength . a ncl osteogenic rege ne ra tive effect