ABSTRACT
Objective To investigate the effect of preptin on proliferation and differentiation of human osteoblasts. Methods After human osteoblasts were incubated with 10-10, 10-9, 10-8 , 10-7 mol/L preptin for 24 h,the proliferation of osteoblasts was determined by[3H]thymidine incorporation and alkaline phosphatase (ALP)activity was assayed by spectrophotometric measurement. The phosphorylation levels of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase ( MAPK), extracellular signal-regulated kinase (ERK) 1/2 were assayed by Western blot. ERK inhibitor PD98059, p38MAPK inhibitor SB203580, and JNK inhibitor SP600125were used for investigating the signal pathway of preptin-stimulated osteoblast proliferation and differentiation.Results Preptin dose-dependently increased human proliferation of osteoblasts and ALP activity with the maximum effect at the concentration of l0-9 mol/L (both P<0.01 ). Preptin stimulated ERK phosphorylation in human osteoblasts, but not p38 MAPK and JNK phosphorylation. PD98059 blocked preptin-sitmulated human osteoblasts proliferation and ALP activity (both P<0.05 ), while SB203580 and SP600125 had no effect. Conclusions Preptin promotes the proliferation and differentiation of human osteoblasts through ERK pathway.
ABSTRACT
PURPOSE: This research is to clarify utilization and efficiency of porous coated NiTi alloy by observing its affinity on human osteoblast. In this study, the biocompatibility of porous NiTi alloy was analyzed by investigating the biological activity and growth patterns of osteoblasts on NiTi alloy in vitro, followed by comparative analysis of their activity on commercial titanium based alloy (TBA) and tissue culture polystyrene (TCP), as a control. MATERIALS AND METHODS: The human osteoblasts were obtained from the iliac crest of a normal adult and cultured with routine maneuver. A seeding of cultured human osteoblasts to each group (NiTi alloy : experimental 1 group, TBA: experimental 2 group, TCP: control group) was done at the 15th day of primary culture. At the 4th, 7th and 10th seeding day, we observed the morphology of cultured cells on the surface of materials using scanning electron microscope and measured the amount of biosynthesis of cell protein and activity of alkaline phosphatase. RESULTS: In the scanning electron microscope study, the osteoblasts in experimental 1 and 2 groups were proliferated well in similar levels. However in control group, growth of osteoblasts were significantly retarded than experimental 1 and 2 groups. And the biosynthesis of proteins and activity of alkaline phosphatase were significantly increased in experimental 1 and 2 groups time dependently but decreased apparently in control group. CONCLUSION: The porous NiTi alloy which was proved to have good affinity and biocompatibility on human osteoblasts could be used as one of press-fit implants in orthopaedic fields.
Subject(s)
Adult , Humans , Alkaline Phosphatase , Alloys , Cells, Cultured , Memory , Osteoblasts , Polystyrenes , TitaniumABSTRACT
Objective: To study what are needed during the invasion of Staphylococcus aureus into cultured human osteoblasts.Methods: Mid-logarithmic growing Staphylococcus aureus 6571 was prepared. Human osteoblasts were cultured from bone explants. Chloramphenicol, rifampicin, novobiocin, cycloheximide, and monodansylcadaverine were used as inhibitors of either bacteria or cells to study their roles in the invasion of Staphylococcus aureus into osteoblasts. Results: Chloramphenicol, rifampicin, novobiocin, and monodansylcadaverine decreased the invasive ability of the bacteria; while cycloheximide increased the ability.Conclusion: De novo protein as well as RNA-and DNA-synthesis by the bacteria is necessary for invasion. The inhibition of osteoblast protein synthesis increases the uptake of the bacteria.
ABSTRACT
Using human fetal osteoblasts (OB) as an in vitro model, we observed the effects of vitamin D2 and hydrocortisone on the traget cells - OB. The results showed that in OB culture, 1,25(OH)2D3, at the concentration of 10-3 mol / L, stimulated alkaline phosphatase activity and the synthesis of ?-carboxy-glutamic acid containing protein (osteocalcin or BGP) but inhibited OB growth. 24,25 (OH)2D3 didn't show such effects. Hydrocortisone at the concentration of 10-6 mol / L inhibited the stimulation of osteocalcin synthesis by