| As we all know, fracture healing takes a long time. The statistics resultsshow[1]that there is about5%to10%with delayed union or nonunion inpatients with fracture resulting in bad limb function, even seriouscomplications. Clinical observations and studies have shown that the fracturehealing with traumatic brain injury would be accelerated[2].The unknownhumoral factors in the blood circulation after head injury can enhanceosteogenesis effect.[3]Serotonin and nerve growth factor(NGF)belong to important neurotrans-mitter serotonin that released to blood circulation through some means aftertraumatic brain injury Thelevel of NGFs raised and the level of serotoninlowered after head injury. These changes play an important role infracture[4]healing process.It is confirmedthat NGF and its receptor exist in thebone tissue and the fracture callus. topical administration of NGF has obviousrole in accelerating the healing of the fracture. The study confirmed[5]thatreceptor mRNA of5-HT (2b) expressed in the osteoblasts, osteocytes,fibroblasts. The new study found that serotonin can inhibit bone loss. Undercertain conditions, Bone marrow mesenchymal stem cells (BMSCs)can turnintoosteogenic cells directly[6].Boes[7]found that osteogenic factor in braintrauma patient serum can promote fracture healing through undifferentiatedmesenchymal stem cells turning into osteoblasts transformation. The purposeof this experiment is to study the role of the nerve growth factor andserotonin accelerating bone marrow mesenchymal stem cells intoosteoblasts.To reveal mechanism of theaccelerated healing of fracture withtraumatic brain injury for prevent further delayed union, nonunion and senileosteoporosis.Object: To explore the role and interaction of Serotoninand NGF in the process when mesenchymal stem cells in the bone marrow in turn intoosteoblastfor promoting the conversion of mesenchymal stem cells intoosteoblasts.Method: Whole bone marrow adherence method was used in thisexperiment. the rabbit bone marrow mesenchymal stem cells （BMSCs）wereisolated and cultured to the third generation for being induced to osteoblasts.Serotonin, and NGF were as interference factors in this process.1The3rd generation BMSCs with good growth status were collected andwere inoculated in8flasks by1x10~5/L concentrations.These materials weredivided into two groups(containing4group) of1and2, and cultured for14days and21days.Cells of the control group, only in the conditioned medium(volume fraction of10%FBS low glucose DMEM medium in group A1,0.1μmol/L dexamethasone,50mg/L ascorbic acid,10mmol/Lβ-sodium glycerop-hosphate,100U/mL penicillin,100U/mL streptomycin) induced transform-ation. B1NGF group, C1group of serotonin, D1NGF and serotonin group.2group A2cells of the control group, only the conditioned medium (volumefraction of10%FBS low glucose DMEM medium,0.1μmol/L dexametha-sone,50mg/L ascorbic acid,10mmol/Lβ-sodium glycerol phosphate,100U/mL penicillin,100U/mL streptomycin) induced transformation. B2is the NGFgroup serotonin group, C2, D2of NGF and serotonin groups.2Detection methods2.1Western blotting analysis of collagen Ⅰ2.2Secretion of the enzyme-linked immunosorbent assay (ELISA)Quantitative analysis of osteocalcin2.3Immunohistochemical qualitative analysis of Calcified nodules2.4Microplate assay alkaline phosphatase activityResults: After induction microplate assay alkaline phosphatase activityof osteoblasts were increasedas follow:D1> B1> C1> A1(P <0.01).Immunohistochemical qualitative analysis of Calcified nodules waspositive. ELISA quantitative analysis of the amount of osteocalcin D2> B2>C2> A2 (P <0.01).conducted Western blotting analysis of collagen Ⅰ D1> B1>C1> A1(P <0.01).Conclusion:This experiment confirmed that NGF and serotonin canpromote the conversion of mesenchymal stem cells into osteoblasts. In thisprocess, the NGF effective than the serotonin, the combination is better thanthe simple application of NGF effects. The activity of alkaline phosphatase,osteocalcin secretion and the amount of type I collagen protein in D1and D2groups were higher than other groups. There are synergies between serotoninand nerve growth factor in the process of conversion of mesenchymal stemcells into osteoblasts. |
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