A Comparative Study on the Biological Characteristics of Human Periodontal Ligament Stem Cells and Orofacial Bone Marrow Stromal Cells
|WangQinTao; DongGuangYing; WangXinWen
|Fourth Military Medical University
|Orofacial bone Human bone mesenchymal stromal cells Humanperiodontal ligament stem cells potential differentiation
Periodontal diseases that involve the destruction of periodontal tissuesincluding cementum, periodontal ligament (PDL) and alveolar bone are amajor cause of tooth loss in adults. At present, tissue engineering is the idealway to achieve periodontal regeneration. It includes three elements: the seedcells, scaffold materials and growth factors. Exelcymosis is needed to obtainperiodontal ligament stem cells which limits its clinical application, soseeking for other proper seed cells has been one of the international hotspots.Many previous experiments have shown that orofacial bone marrow stromalcells are highly proliferative and exhibit osteogenic properties superior to iliaccrest BMSCs. In this study we compared the biological characteristics oforofacial bone marrow stromal cells with those of periodontal ligament cellsin vitro and in vivo in order to explore the potential for orofacial bone marrowstromal cells as a new kind of seeding cells to regenerate periodontal tissue.Primary human orofacial bone marrow stromal cells (OF-MSCs) and periodontal ligament stem cells (PDLSCs) were isolated and cultured in vitro.Cell morphology, growth curve, colony formation ratio (CFR), expression ofSTRO-1and CD146were analyzed by inverted contrast microscope, cck-8and immunofluorescence staining. After certain induction, the adipogenicdifferentiation potential and the alkaline phosphatase activity were tested. Theexpression of bone-associated genes was tested by RT-PCR. The adhesion ofOF-MSCs and PDLSCs on hydroxyapatite beta tricalcium phosphate(HA/β-TCP) was observed by scanning electron microscope (SEM).OF-MSCs and PDLCs were transplanted into immunocompromised mice tocompare their bone regeneration capacity.Results:1. Both OF-MSCs and PDLSCs showed fibroblast-like morphology andclonal growth pattern. Growth curve showed that they had similar increasingtrend, while BMSCs got into the platform period earlier; PDLSCs andOF-MSCs expressed the mesenchymal stem-cell markers STRO-1andCD146.2. After two weeks of culture with an adipogenic inductive cocktail,OF-MSCs and PDLSCs developed into oil red O-positive lipid-laden fat cells.Both OF-MSCs and PDLSCs expressed bone-associated genes (OCN, OPN,ALP, runX2and BMP-2) after osteogenic induction, and the OCN and OPNgene expression in OF-MSCs were stronger and earlier.3. The two cell types demonstrated low levels of alkaline phosphataseactivity when cultured in non-osteogenic medium, but OF-MSCs producedhigher levels of alkaline phosphatase activity than PDLSCs in response toosteogenic induction.4. OF-MSCs and PDLSCs showed good adhesion to HA/β-TCP. 5. After8weeks of transplantation, PDLSCs and OF-MSCsdifferentiated into bone-like cells that formed a bone-like structure on thesurface of the HA/β-TCP carrier.Conclusion: OF-MSCs and PDLSCs both show the general characters ofMSCs and a certain level of osteogenesis potential. In vivo, the OF-MSCsshow better osteoblast differentiation capacity. We still need furtherinvestigation to confirm whether it is a proper seeding cell for periodontalregeneration.