Effect of the compound of poly lactic-co-glycolic acid and bone marrow stromal cells modified by osteoprotegerin gene on the periodontal regeneration in Beagle dog periodontal defects / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of the osteoprotegerin (OPG) gene-modified autologous bone marrow stromal cells (BMSCs) on regeneration of periodontal defects, and to provide new experimental evidence to explore the gene therapy for periodontal disease.</p><p><b>METHODS</b>pSecTag2/B-opg was transduced into BMSCs by lipofectamine 2000. The expression of OPG protein in the BMSCs was detected by immunocytochemistry and Western blot. Inverted phase contrast microscope and scanning electron microscopy (SEM) were used to observe the morphology and proliferation of the BMSCs(OPG) on on the surface of the poly lactic-co-glycolic (PLGA). Horizontal alveolar bone defect (4 mmx4 mmx 3 mm) were surgically created in the buccal aspect of the mandibular premolar, and were randomly assigned to receive BMSCs(OPG)-PLGA (cells/material/OPG), BMSCs-PLGA (cells/material), PLGA (material), or root planning only (blank control). The animals were euthanized at 6 weeks post surgery for histological analysis. The height of new alveolar bone and cementum and the formation of new connective tissue were analyzed and compared. All data were statistically analyzed using the q test.</p><p><b>RESULTS</b>The BMSCs transfected by human OPG gene can highly express OPG protein. SEM observations demonstrated that BMSCs(OPG) were able to proliferate and massively colonize on the scaffolds structure. After 6 weeks, the height of new alveolar bone and cementum and the formation of new connective tissue were significantly greater in the experimental group than in the control groups (P < 0.05).</p><p><b>CONCLUSION</b>BMSCs(OPG)-PLGA can significantly promote the regeneration of dog's periodontal bone defects. Gene therapy utilizing OPG may offer the potential for periodontal tissue engineering applications.</p>

Establishment and identification of transiently expression system of bone marrow stromal cells modified by osteoprotegerin gene / 华西口腔医学杂志

<p><b>OBJECTIVE</b>In oder to treat periodontitis by using tissue engineering and gene engineering technology, the article established an transient expression system of bone marrow stromal cells (BMSC) modified by osteoprotegerin (OPG) gene and detected its expression using eukaryotic secreted expression pSecTag2/B-OPG plasmid.</p><p><b>METHODS</b>By solation and culture of BMSC in vitro, the identified recombined plasmid was transiently transfected into BMSC by Lipofectamine 2000 and OPG expression in BMSC was determined by RT-PCR and Western blot in 6 weeks.</p><p><b>RESULTS</b>The fragments of the recombinant plasmid digested with Hind III, EcoR I and BamH I and examined by 10 g/L agarose electrophoresis, were consistent with predicted size. The sequence of OPG was identical to the sequence provided by GeneBank [gi:33878056]. OPG transcribing in BMSC was confirmed by RT-PCR and OPG sustainable expressing in BMSC was detected by Western blot in 39 days.</p><p><b>CONCLUSION</b>The transiently expression system of BMSC modified by OPG gene was successfully established.</p>

A novel mutation of MSX1 gene in a Chinese pedigree with oligodontia / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To detect the MSX1 gene mutation in a Chinese family with oligodontia.</p><p><b>METHODS</b>Blood samples were obtained from seven affected and seven unaffected individuals in the pedigree. All exons and flanking intronic boundaries of the MSX1 gene were amplified with polymerase chain reaction technique and then directly sequenced. The website of bioinformatics was used to predict the effect of the mutation on the function.</p><p><b>RESULTS</b>A splicing mutation (IVS1-2A > G) was found at position -2 near the 3' end of the IVS1 of MSX1, which made a change of the intron 1 splice acceptor site. None of the mutation was found in normal individuals of the family and in 100 unrelated healthy matched control individuals.</p><p><b>CONCLUSIONS</b>IVS1-2A > G was a novel splicing mutation identified in the MSX-1 gene and it might be responsible for nonsyndromic oligodontia in this family.</p>

Relationships between periapical lesion and IL-1, TNF-alpha gene expression in rat / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To understand the effects of the IL-1, TNF-alpha cytokines on the pathogenesis of periapical lesions by investigating its gene expression in rat.</p><p><b>METHODS</b>The model was established by surgically exposing mandibular molar teeth and left open to permit infection from the oral environment. The SD rats were killed at 1, 2, 3, 4 weeks and mandibular molar teeth X-ray were taken. In situ hybridization was used to test IL-1alpha, IL-1beta, TNF-alpha mRNA expression in periapical area and the kinds of positive cells were identified. Using image analysis system analyzed gene expression semi-quantified.</p><p><b>RESULTS</b>IL-1alpha, IL-1beta and TNF-alpha mRNA were all expressed beginning at 1 week, peaked at 3 weeks, and declined somewhat at 4 weeks, but IL-1beta mRNA was expressed at much lower levels with the same kinetics (P<0.01). Most of the staining occurred in areas that had heavy inflammatory infiltrate, fibroblasts, or endothelial cells. There was a statistically significant correlations between the area of periapical lesion and the number of positively stained cells for IL-1alpha and for TNF-alpha (IL-1alpha: r=0.875, P<0.001; TNF-alpha: r=0.858, P<0.001), and between the number of positive cells for IL-1alpha and that of for TNF-alpha (r=0.969, P<0.001).</p><p><b>CONCLUSIONS</b>IL-1alpha and TNF-alpha genes are highly expressed in developing periapical lesions in rat, which supports the hypothesis that these two cytokines play a key role in pulpal and periapical pathogenesis, including the concomitant bone destruction.</p>