AIM:To observe the expression of epidermal growth factor receptors(EGFR) of gingival tissue in periodontitis. METHODS: The expression of EGFR was determined by using immunohistochemical techniques in gingival tissue of 15 healthy individual, 32 cases with adult periodontitis (AP) and 12 cases with juvenile periodontitis (JP). RESULTS: Expression of EGFR was mainly located on basal cell membranes in healthy gingiva, and the staining intensity was faint. In AP cases, expression of high level EGFR was mostly observed on the membranes of epithelial cell in the periodontal endopocket or junctional epithelium, intensity of staining appeared to decrease gradually with the differentiation of keratinocytes, and the horny cell layer was not stained by the antibody. In JP cases, strong positive staining was present on membrane of epithelial cells in the germinative layer of gingival tissue. There was an apparent difference between healthy gingiva and AP or JP (P＜ 0.01 ), or AP and JP (P＜ 0.01). CONCLUSION: The distribution and expression of EGFR in gingival epithelium of periodontitis showed obvious differ- euce. The data indicated that EGFR may affect apical migration of junctional epithelium, and may play a role in development of AP and JP.

Objective:To compare the proliferation and osteogenic differentiation between human bone marrow mesenchymal stem cells from orofacial bone(OMMSCs)and those from long bone(BMMSCs).Methods:OMMSCs were isolated from orthognathic surgical sites and cultured by limited dilution.BMMSCs were obtained from bone marrow of volunteers and isolated by density gradient centrifugation method.The surface markers of the cells were detected by flowcytometry.Single-colony formation,CCK assay and cell circle analyses were conducted.Osteogenic differentiation ability was evaluated by ALP activity test and Alizarin red staining after osteogenic induction culture.Results:The cell surface markers STRO-1 and CD105 of both stem cells were positive,CD34,CD31 and CD45 were negative. OMMSCs generated significantly higher numbers of colonies than BMMSCs.In addition,OMMSCs had a higher proliferation rate and more cells in proliferative(S +G2 )stage than BMMSCs.After osteogenic induction for 3,5,7 and 10 d,OMMSCs showed higher levels of ALP activity.OMMSCs formed significantly more mineralized nodules than BMMSCs after 21-day ostogenic induction.Conclusion:The proliferation and osteogenic differentiation capacity of OMMSCs are higher than those of BMMSCs.

Objective:To investigate the trait of exosomes serected by mesenchymal stem cells derived form orofacial bone(OMMSCs-Exo) and the communication between the exosomes and macrophages.Methods:OMMSCs were isolated from orthognathic surgical sites and cultured by limited dilution.Their cell surface markers were characterized by flow cytometry.the rate of colony formation and the differentiation potential of OMMSCs were evaluated.Exosomes were prepaired from the culture supernatants of OMMSCs(P4-P6).Transmission electron microscopy(TEM) and western blot were used to identify the exosomes.The expression of miRNAs associated with immunity such as miR-223 and miR-let-7c were determined by Real-time RT-PCR.Human peripheral blood mononuclear cells(PBMCs) were isolated from health donor and co-cultured with OMMSCs-Exo.After co-cultured for 24 h,the communication between exosomes and macrophages was tested using a confocal microscope.Results:Human OMMSCs were proved to have the characteristics of mesenchymal stem cells.The diameter of OMMSCs-Exo ranged from 40 to 160 nm.The OMMSCs-Exo expressed CD63 and CD81 and contained miRNAs associated with immune regulation such as miR223 and miR-let-7c.OMMSCs-Exo could be uptaken by macrophages.After co-culture of OMMSCs-Exo with marcrophages for 72 h,miR223 expression in macrophages increased.Conclusion:OMMSCs-Exo has the potential of immune regulation.

Objective:To compare acetyltransferase MORF level in periodontal ligament stem cells( PDLSCs) derived from healthy individuals ( H-PDLSCs) with those derived from the individuals with periodontitis ( P-PDLSCs ) . And to determine the effect of MORF on the osteogenic differentiation potential of PDLSCs. Methods: Human H-PDLSCs and P-PDLSCs were cultured and cloned with limited dilution method. H-PDLSCs were stimulated by LPS, TNF-α, IL-β and the mix of the 3 inflammatory factors to imitate inflammatory environment ( IP-PDLSCs ) . Quantitative RT-PCR and Western Blot were applied to examine different expression of MORF in H-PDLSCs and P-PDLSCs. Western Blot was applied to detect expression of MORF in IP-PDLSCs. Quantitative RT-PCR, Western Blot and alizarin red staining were applied to determine osteogenic differentiation potential of H-PDLSCs with MORF knock-down. Results:Quantitative RT-PCR and Western Blot showed lower expression of MORF in P-PDLSCs compared with H-PDLSCs( P<0. 05). Western Blot revealed lower expression of MORF in IP-PDLSCs. Quantitative RT-PCR, Western Blot and alizarin red stai-ning indicated osteogenic differentiation potential was inhibited in H-PDLSCs with MORF knockdown(P<0. 05). Conclusion: Peri-odontitis can suppress the expression of MORF in PDLSCs and inhibite the osteogenic differentiation potential of PDLSCs.