OBJECTIVE: To isolate and characterize mesenchymal stem cells (MSCs) derived from bone marrow of Banna minipig inbred line (BMI). METHODS: BMI-MSCs was isolated from bone marrow by density gradient centrifugation and cultured in DMEM (containing 15% bovine serum) at 37 degrees C with humidified 5% CO2. These cultured stem cells were characterized in clonal growth, expression of specific markers and capability of differentiation. RESULTS: Mesenchymal stem cells were proliferative and could be expanded rapidly in vitro. Clonal growth of these cells can be observed when small amount of cells was inoculated. These cells were SH2, SH3, SH4, SB10 and SB21 positive. And it was proved that these cells possess osteo-differentiation ability, up-regulated alkaline phosphatase expression and calcium secretion after osteosupplement was added into the media for several days. CONCLUSION: Mesenchymal stem cells derived from bone marrow of BMI possess the general characters of stem cell.
Objective To analyze MC3T3E1 cell morphology, prol iferation, and osteogenic differentiation in fibrin gel (FG) so as to lay a fundament for use of FG in tissue engneering. Methods MC3T3E1 cells were incubated in three concentrations (20, 10 and 5 mg/mL)of FG as the experimental groups (groups A, B and C) and in the common medium culture as the control group (group D). The cell morphology and distribution in FG were observed by inverted phase contrast microscope and confocal laser scanning microscope at different time. The cell prol iferation was assessed by fluorospectrophotometer. The alkal ine phosphatase (ALP) activity was detected by automatic biochemistry analyses and von Kossa staining was used to analyze calcium salts mineralization. RT-PCR was used to analyze the ALP and bone sialoprotein (BSP)mRNA expression at 14 and 21 days. Results In groups A, B and C, the MC3T3E1 cells had long processes which connected each other and formed network; but fusiform or cube cells were observed in group D at 21 days. The fluorescence intensity was increased gradually with time, was the highest at 14 days and the lowest at 28 days in group D; it was highest in groups A, B and C at 28 days, there were statistically significant differences when compared with group D (P lt; 0.05). The ALP activity was increased gradually with time, and it was the highest at 28 days in group D and at 21 days in groups A and B, there were significant differences (P lt; 0.05), no statistically significant differences compared with group D at other time points (P gt; 0.05). The mineral ization nodus were seen at 21 and 28 days in group A, but no mineral ization nodus was seen in group D at 28 days. The RT-PCR results showed the mRNA expressions of ALP and BSP were enhanced in group A when compared with group D (P lt; 0.05). Conclusion The osteogenic differentiation was most obvious and cell prol iferation was most active after 21 days of incubation in FG.
Objective To study the function and mechanism of G protein coupled receptor kinase interacting protein 1(GIT1) RNA hairpin (GIT1-RNAh) in osteoblast migration. Methods The sixth passage osteoblasts were divided into 2 groups and were infected by GIT1-RNAh (experimental group) and green fluoresence protein RNA hairpin (GFP-RNAh) (control group) adenovirus for 12 hours respectively. Each group was further classfied into two groups according to with or without platelet-drived growth factor (PDGF) stimulation. The GIT1 expression and Paxillindistribution was analyzed by immunofluorescence staining. Paxillin phosphorylation was detected by Western Blot. The localization of Paxillin was determined by co-immunofluorescence staining after transfection with cyanine fluorescence protein tagged GIT1RNAh (CFP-GIT1-RNAh)(experimental group) and GFP-RNAh (CFP-GFP-RNAh)(control group). The role of GIT1-RNAh (experimental group) and GFP-RNAh (control group) adenovirus in osteoblasts migration was determined by wound healing assay. Results Immunofluorescence staining results showed that the GIT1-RNAh significantly inhibited endogenous GIT1 expression, interfered Paxillin distribution.Western Blot results showed that Paxillin phosporylation was obviously inhibited in osteoblasts infected with GIT1-RNAh adenovirus (P＜0.05). The wound healing assay results howed that GIT1-RNAh adenovirus significantly inhibited osteoblast migration induced by PDGF. Conclusion GIT1-RNAh inhibits osteoblasts migration by interfering paxillin distribution and decrease Paxillin phosphorylation.
Objective To observe effects of the core binding factor α1 (Cbfα1) in its promoting differentiation of the rabbit marrow mesenchym al stem cells (MSCs) into osteoblasts. Methods The rabbit marrow MSCs were isolated and cult ured in vitro and were divided into 3 groups. In the control group, the marr ow MSCs were cultured by DMEM; in the single inducement group, they were cultured by the condition medium (DMEM, 10% fetal bovine serum, dexamethasone 10 mmol/L, vitamin C 50 mg/L, and βGP 10 mmol/L); and in the experimental group , the ywere transfected with AdEasy1/Cbfα1,and then were cultured by the condition m edium. The alkaline phosphatase(ALP) activity and the experission of osteocalcin as the osteoblast markers were measured with the chemohistological and immunohi stochemical methods at 3 days，1，2，3，and 4 weeks after inducement. Results More than 90% MSCs were grown well in vitro. The GFP was positive in MSCs after their being transfectived with AdEasy1/Cbfα1. The ALP activity and the experission of osteocalcin were significantly upregulated in the transfection group compared with those in the single inducement group and the control group at 1, 2, 3, and 4 weeks （Plt;0.05）.The mineralized node began to appear at 2 weeks in the experiment al group and the single induction group, but did not appear in control group. Conclusion Cbfα1 can obviously promote differentiation of the rabb it marrow mesenchymal stem cells into the osteoblasts.
Objective To observe the effects of cobalt chloride (CoCl2)-simulated hypoxia on VEGF and TGF-β1 expression and to provide theoretical basis for deci phering the molecular mechanism of cl inical distraction osteogenesis. Methods The mandibular osteoblasts were obtained from newborn Wistar rats within 24 hours and cultured and purified through modified enzymatic digestion. The morphological and histological changes of cells were evaluated by the HE staining,the histochemical staining for ALP, the collagen I immunohistochemistry staining and the calcified nodules staining, and the growth curves were drawn. The best cells of the 3rd-passage rats were treated with CoCl2, and then immunofluorescence was used to detect the expressions of VEGF and TGF-β1 at 0, 3, 6, 9, 12 and 24 hours after culture. Results The HE staining demonstrated that the cellular forms were diverse, triangular, polygonal, circular and scaly and so on. The prominence varied in length and extended outwards. The nucleus was clearly discernible. The cytoplasma was rich and pink, with the nucleus royal purple. Sometimes 2 cell nuclei were seen. At the crowded place, cellular form was not clear, the dividing l ine was indistinct, and just the great-circle nuclear cells could be seen. The ALP immunohistochemistry staining demonstrated that the cell butcher nature appeared black pellets, the cell nucleus outl ine was unclear, and at the cell compact district, massive mascul ine cells could be seen clearly. The collagen I immunohistochemistry staining demonstrated that mascul ine cells were seen evenly, cytoplasma appeared yellowish brown especially around the nucleus. However, yellowish brown pellets were not seen in negative cells. The osteoblast calcium tubercle staining demonstrated that the cells gathered in the opaque region with the shape of tubercle after15 days of culture. After al izarin red staining, the reddish orange pigmentation appeared. At various time points, weak VEGF fluorescence was seen in the cells in the control group under the laser confocal microscope. As the hypoxia time prolonged, VEGF fluorescence of cells in the experimental group intensified, and reached the peak 9 hours after peration, and then dropped to the normal level. At various time points, TGF-β1 fluorescence was found in both groups under the laser confocal microscope, and fluorescence intensity in the control group was sl ightly ber than that in the VEGF control group. In the experimental group, TGF-β1 expression had short-term increase 3 hours after hypoxia, and reduced gradually with the prolonging of hypoxia time. Conclusion The method of culturing osteoblast from Wistar rats mandibular is practicable. The cells can be used for further studies. Moderate hypoxia can affect bone synthesis and turnover in distraction osteogenesis and up-regulate the expressions of VEGF and TGF-β1.
Objective Lots of metal ions accumulation and over-expression of receptor activator of NF-κB l igand (RANKL) around the prosthesis could be found in revision of total hip arthroplasty. To investigate the relationship between metal ions and aseptic loosening by observing the effects of Co2+ and Cr3+ ions on the expression of RANKL and osteoprotegerin(OPG) from osteoblast. Methods Osteoblasts were cultured in vitro at the density of 1 × 105 cells/mL, and were divided into 2 groups according to different culture solutions. In control group, osteoblasts were cultured with normal medium without CoCl2 and CrCl3. In experimental group, osteoblasts were cultured with the medium including CoCl2 (10 mg/ L) and CrCl3 (150 mg/L) solutions. The RT-PCR and ELISA methods were appl ied to detect the mRNA expression of RANKL and OPG and protein level at 24 and 48 hours after co-cultured, respectively. Results RT-PCR revealed that the mRNA expression of RANKL and OPG could be found in two groups at 24 and 48 hours after co-cultured, the expression was higher in the experimental group than in control group, especially the expression of RANKL, showing significant difference (P lt; 0.05). At 24 and 48 hours after co- cultured, the ratios of RANKL mRNA to OPG mRNA in the experimental group were 0.860 and 1.232, respectively, which were significantly higher than those in the control group (0.695 and 0.688,P lt; 0.05). ELISA revealed that the protein level of RANKL and OPG in experimental group were significantly higher than those in the control group (P lt; 0.05). Conclusion Co2+ and Cr3+ can stimulate the mRNA expressions of RANKL, OPG and secretion of those protein from osteoblasts, especially increase of the RANKL, which promotes the formation and activation of osteoblasts and the generation of aseptic loosening.
OBJECTIVE To detect the immunoreaction after osteoblast xenotransplantation and to investigate the possibility of heterogenic osteocyte transplantation and tissue engineered bone reconstruction. METHODS: Rat osteoblasts were isolated by two-part bony digestion/elements in culturing, and incubated in vitro at 37 degrees C, 5% carbon dioxide for 5 days until they multiplied and formed a monolayer on the bottom of dish. Twenty-eight rabbits were divided into 3 groups. Autograft of osteoblasts(group A), xenograft of osteoblasts(group B) and normal saline(group C) were implanted into the rectus abdominus muscle. The immunological and histological observations were performed after 1, 2, 4 and 8 weeks of transplantation. RESULTS: Cultured cells reached confluence within 5 days and was identified as osteoblasts by ALP staining and Bon kossa staining. The result of host versus graft reaction was negative. In group B, specific antibody reaction was detected 2 weeks and 4 weeks after transplantation. Cell mediated cytotoxicity was detected after 2 weeks, reached the peak value 4 weeks later, and then began to decline 8 weeks later. HE staining showed mass inflammatory cells and no ectopic ossification after 8 weeks. CONCLUSION: Heterogenic osteoblast transplantation will lead to an obvious change in host humoral and cellular immunity and lost the ability of bone formation. So, it can not be used for the reliable cell sources for osteocyte transplantation or tissue-engineering bone reconstruction.
Abstract An experiment was carried out to investigate the possibility of the establishment of an osteoblasts bank which could supply osteoblasts in repairing bone defect. Osteoblasts were isolated from thetibial periosteum of eight New-Zealand rabbits and cultured in votro. A bone defect, 1.5cm in length was made in both radii of each of the 8 rabbits. The cultivated osteoblasts, gelfoam as a carrier were randomly implanted into the defects of the radii of rabbits. Accordingly, the contralateral radial defects wereimplanted with gelfoam absorbed with the Hanks solution as control. The healing of bone defects was evaluated by roentgenographic examination at 2, 4, 8 and 12 weeks after operation, respectively. It was shown that the implanted cells had osteogenetic capability and could be possible to promote healing of the bone defects. It was suggested that further study needed to be carried out in this field.
Objective To investigate the effects of insulin-like growth factor 1（IGF-1） and ethanol (EtOH) on the changes in the osteoblast proliferation and the osteoblast function under the normal serum concentration and serum starvationMethodsThe osteoblasts harvested from the SD rat calvaria were incubated in the following six conditions according to the supplements in DMEM: the F15group：15% newborn calf serum (NCS)； the F15/EtOH group：100 mmol/L of EtOH added to 15% NCS； the F2 group：2% NCS； the F2/EtOH group：100 mmol/L of EtOH added to 2% NCS；the F2/IGF-1 group：25ng/ml of IGF-1 added to 2% NCS；the F2/IGF-1/EtOH group：100 mmol/L EtOH added to 25 ng/ml IGF-1 and 2% NCS. The osteoblasts were analyzed by the MTTassay, alkaline phosphatase（ALP） activity, and RTPCR at 24, 48, 72 and 96h ours after the culture. Results The absorbance (A), the ALP activity, and the expression of BGP mRNA (the proliferation and function indicators of the osteoblasts) were significantly decreased in the F15/EtOH group at all the time points when compared with those in the F15the group (P＜ 0.05); the above 3 indicators were significantly decreased in the F2 groupwhen compared with those in the F15 group (P＜0.05); they were significantly decreased in the F2/EtOH group when compared with those in the F2 group (P＜0.05); however, the indicators in the F2/IGF-1 group were significantly increased when compared with those in the F2 group (P＜0.05); the A value in the F2/IGF-1/EtOH group was not significantly decreased when compared with that in the F2/IGF-1 group, with an exception of the A value at 24 hours (P＞0.05); however, ALP and BGP mRNA were significantly decreased (P＜0.05). All the indicators were significantly increased when compared with those in the F2/EtOH group (P＜0.05) Conclusion Ethanol can inhibit the osteoblast proliferation and the osteoblast function, and can increase the inhibition when the osteoblasts were cultured under the serum starvation. This may be one of the mechanisms for alcoholic bone disease. IGF-1 can prevent the inhibition of the osteoblasts under the serum starvation and counteract the ethanolinduced proliferation inhibition; therefore, IGF-1 is an alternaive therapeutic intervention for alcoholic bone disease.
OBJECTIVE: To evaluate the cellular compatibility of three natural xenogeneic bone derived biomaterials. METHODS: Three types of natural xenogeneic bone derived biomaterials were made with physical and chemical treatment, composite fully deproteinized bone(CFDB), partially deproteinized bone(PDPB) and partially decalcified bone(PDCB). Three types biomaterials were cocultured with human embryonic periosteal osteoblasts. The cell growth, attachment, cell cycle, alkaline phosphatase activity were detected to evaluate the cellular compatibility to biomaterials. RESULTS: Osteoblasts attached on all three biomaterials and grew well, the effect of three biomaterials on cell proliferation was PDCB gt; PDPB gt; CFDB. The cell cycle was not obviously affected by three biomaterials. The effect of three biomaterials on alkaline phosphatase activity of osteoblasts was PDCB gt; PDPB gt; CFDB. CONCLUSION: CFDB,PDPB,PDCB have good cellular compatibility without cytotoxic and tumorigenicity, CFDB is the best. The three biomaterials can be used as scaffold materials of bone tissue engineering.