ABSTRACT
<p><b>OBJECTIVE</b>This work investigated mesenchymal stem cells (MSCs) modified with Runt-related transcription factor 2 (Runx2) therapy for bone regeneration in rabbit mandibular distraction osteogenesis.</p><p><b>METHODS</b>Forty-eight New Zealand mature white rabbits were randomly divided into three groups after the rabbit model of mandibular distraction osteogenesis was established: reconstruction plasmid modified with Runx2 (group A), plasmid without Runx2 (group B), and the same dose of saline as control (group C). At the fifth day of distraction phase, MSCs with reconstruction plasmid modified with adv-hRunx2-gfp were injected into the distraction gap of group A. MSCs with reconstruction plasmid modified with adv-gfp was injected into the distraction gap of group B, whereas group C was injected with the same dose of saline. At 8 weeks after injection, all animals were sacrificed, and the distracted mandibles were harvested. The general imaging histological observation and three-point bending test were used for evaluation.</p><p><b>RESULTS</b>CT plain scan and histological analysis confirmed that the amount of new bone forming in the distraction gap of group A was significantly higher than those in groups B and C. Dual-energy X ray and three-point bending test results also showed that the bone mineral density, bone mineral content, and maximum load of the distraction gap of group A were significantly higher than those of groups B and C (P<0.01).</p><p><b>CONCLUSION</b>Runx2-ex vivo gene therapy based on MSCs can effectively promote the bone regeneration in rabbit mandibular distraction osteogenesis and shorten the stationary phase. Therefore, reconstruction of craniofacial fracture would be a valuable strategy</p>
Subject(s)
Animals , Rabbits , Absorptiometry, Photon , Bone Density , Bone Regeneration , Physiology , Core Binding Factor Alpha 1 Subunit , Genetics , Pharmacology , Genetic Therapy , Mandible , Physiology , General Surgery , Mesenchymal Stem Cell Transplantation , Methods , Mesenchymal Stem Cells , Osteogenesis , Genetics , Osteogenesis, Distraction , Methods , Plasmids , Random Allocation , Transcription Factors , Genetics , Physiology , Treatment OutcomeABSTRACT
BACKGROUND:The process of oxidative stress that impacts the curative effect exists in the region which accepts cel transplantation. However, there are few reports about the effects of oxidative stress on human dental pulp stem cels and relevant mechanism. OBJECTIVE:To understand the effect of hydrogen peroxide on the senescence of human dental pulp stem cels. METHODS:Human dental pulp stem cels were isolated and cultured in PBS, 100 and 200 μmol/L hydrogen peroxide for 2 hours, respectively. Cel morphology was observed under inverted microscope, degree of cel senescence monitored by β-galactosidase staining, cel proliferation ability detected by BrdU kit and cel counting method, cytoskeleton of dental pulp stem cels and expression of sirt1 tested using immunofluorescence method, and expression of sirt1 and p16 proteins measured by western blot assay. RESULTS AND CONCLUSION:Dental pulp stem cels exhibited a fibroblast-like morphology with spindle-shaped appearance. After stimulated by hydrogen peroxide, the cel volume was enlarged, theβ-galactosidase staining deepened and the proliferation of dental pulp stem cels reduced. The enhancement of senescence of dental pulp stem cels was accompanied with the increasing concentration of hydrogen peroxide, and in this process, the expression of p16 was raised while the expression of sirt1 was decreased. In conclusion, the senescence of human dental pulp stem cels can be promoted by the stimulation of hydrogen peroxide, and sirt1 and p16 are involved in this process. Our findings may provide a theoretical and experimental foundation for autologous transplantation of dental pulp stem cels.