ABSTRACT
Aim To investigate the role of Wnt/β-cate-nin signaling pathway on the baicalin-induced osteo-genic differentiation in rat bone marrow derived mesen-chymal stem cells ( rBMSC ) . Methods rBMSC was isolated and cultured by adherence screening method. Alkaline phosphatase ( ALP) amount, CFU-FALP and mineralized nodules were compared between each ba-icalin group and vehicle control group at different time points. Real time q-PCR was employed to evaluate the mRNA level of Wnt signaling-related marker ( Wnt10a, GSK-3β,β-catenin and LEF1) after baica-lin treatment. Protein expression of β-catenin and Runx2 was measured by Western blot. Results Ba-icalin significantly increased ALP activities from day 3 to day 7 . The formation of CFU-FALP and mineralized nodules remarkably increased after rBMSC was treated with1, 10, 50 μmol · L-1 baicalin. mRNA levels of Wnt10a, β-catenin, GSK-3β, LEF1and osteocalcin were enhanced significantly in baicalin-treated group compared to control group. Protein expression of β-catenin and Runx2 was also elevated. Conclusion Baicalin ( 0. 1 to 50 μmol · L-1 ) promotes the osteo-genic differentiation and maturation of rBMSC, in which Wnt/β-catenin signaling pathway might be in-volved.
ABSTRACT
Object To investigate the effect of dexamethasone(Dex)of different concentration on the differentiation of the bone marrow stromal stem cells(MSC).Methods MSC were isolated from mice and cultured in vitro.After the third passage,the cells were treated with Dex of different concentration,the expression of typeⅠcollagen mRNA(COL1mRNA),alkaline phosphatase mRNA(ALP mRNA)and adipocyte lipid-binding protein mRNA(ap2mRNA)were detected by quantitative RT -PCR technique.The ratio of the electrophoretic results of the ap2mRNA,COL1mRNA and the ALP mRNA with the house keeping gene of glyceraldehydes-3-phosphate dehydrogenase(GADPH mRNA)respectively,were used to show the relative content of the mRNA.Results COL1mRNA,ALP mRNA and ap2mRNA were ex pressed despite of the difference of the concentration of the Dex.When Dex was1?10 -7 mol/L,the COL1mRNA was0.47?0.12,and ap2mRNA was0.21?0.16;and when Dex was1?10 -8 mol/L,the COL1mRNA was0.96?0.17,and ap2mRNA was0.06?0.03.There was significant statistic difference be-tween the two groups respectively.But the expression of the ALP mRNA were0.35?0.13and0.46?0.24re spectively,there was no significant difference among them.Conclusion Dex could regulate the differenti-ation of the MSCs into adipocyte or osteoblast by regulating special gene expression.In addition,the differ-en tia tion of MSC induced by Dex was bidirectional depending on the concentration of the Dex.When the concentra tion of the Dex was high,it could induce MSC differentiating into adipocytes.This might be the molecular mechanism of the steroid induced osteonecrosis.And the results proved when Dex was1?10 -8 mol/L,it was suitable for inducing MSCs differentiation into osteoblasts.
ABSTRACT
Background: Inter1eukin-6(IL-6) is known to be produced by osteoblastic cells and to have impartant role in regulation of bone remodelling, Most previous studies indicated that IL-6 bas a major role in stimulating osteoclastic resorption by increasing recruitment and proliferation of preosteoclasts. But its autocrine effect on osteoblastic cells has not been well established yet. Therefore, we studied the effects of IL-6 on messenger RNA (mRNA) expression of proteins that are characteristic of osteoblastic cells in human bone marrow stromal (osteoprogenitor) cells (hRMSC). Methods: The expression of mRNAs for alkaline phosphatase, al(1)-collagen, osteopontin and decorin were studied by northern blot analysis after 3 7 days' treatrnent with IL-6 in the concenttation range of 101,000 U/ml. Results: The mRNA levels for any of the osteoblastic proteins studied did not change significantly by IL-6 treatment up to the concentration of 1,000 U/ml. Conclusion: These results suggest that IL-6 does not have a significant role in differentiatian or activities of human bone rnarrow stromal.