[Construction of leptin gene modified tissue engineered composites in vitro].

PURPOSE: To evaluate the feasibility of constructing tissue engineered composites in vitro by combining human leptin (hLEP) gene modified rat bone marrow stromal cells (BMSCs) and guided tissue regeneration collagen membrane (Bio-Gide). METHODS: BMSCs of SD rats were isolated and cultured by whole bone marrow adherent method. BMSCS were transfected with adenovirus carrying hLEP gene (Ad-hLEP-EGFP) and observed under inverted fluorescence microscope. Enzyme linked immunosorbent assay (ELISA) was used to detect the expression of hLEP. The proliferation activity of transfected cells was assessed by MTT assay. Ad-hLEP-EGFP transfected BMSCs were cultured for 24 h in combination with Bio-Gide collagen membrane, hLEP modified tissue engineered composite was observed under laser scanning confocal microscope (LSCM) and scanning electron microscope (SEM). RESULTS: Through Ad-hLEP-EGFP transfection, hLEP was overexpressed in BMSCs, which didn't affect the proliferation of cells. SEM showed hLEP modified BMSCs grew well on Bio-Gide collagen membrane and secreted extracellular matrix. LSCM suggested BMSCs could migrate to different scales of Bio-Gide collagen membrane. CONCLUSIONS: hLEP modified BMSCs can be combined with Bio-Gide collagen membrane and grow well, suggesting that hLEP modified tissue engineered composite can be successfully constructed. The composite might be suitable for periodontal tissue engineering.

[Gene expression of latent TGF-ß binding protein-3 in the follicle of mouse first mandibular molar in mice].

PURPOSE: To observe and analyze the gene expression of latent TGF-ß binding protein-3(LTBP-3) in mice first mandibular molars during tooth eruption period. METHODS: The first mandibular molar germs of KM mice, from postnatal 1.5 to 9.5 days, were dissected. Anatomical microscope was used to observe and separate dental follicles of each time-point. After total RNA extracted from separated dental follicles of the first mandibular molars, reverse transcription-polymerase chain reaction (RT-PCR) was performed using LTBP-3 specific primers to detect its gene expression. Then densitometry analysis was performed using Gene Genius Bio-Imaging system and GeneSnap software. Expression differences between any two time points were assessed by LSD test in one-way ANOVA at α=0.05 level using SPSS 13.0 software package. RESULTS: A circle of fibrae sac like loose tissue could be seen around all the germs in anatomical microscope and could be carefully dissected from the germs. There was an aging progressive gene expression of LTBP-3 in the dental follicles of mice first mandibular molars among the detecting time-points. LSD test analysis revealed that the expression of both P7.5 and P9.5 was higher than that on the P1.5 (P<0.05 and P<0.01, respectively) and P9.5 expression level was higher than that on the P3.5 (P<0.05), while there was no difference in expression between any other two detecting days. CONCLUSIONS: LTBP-3 is confined to have an aging progressive gene expression in the follicles of mice first mandibular molars during tooth eruption period. LTBP-3 may play a role in the events of mice teeth eruption.