Effects of ascorbic acid and ascorbic acid 2-phosphate, a long-acting vitamin C derivative, on the proliferation and differentiation of human osteoblast-like cells.
ABSTRACT In order to investigate the effect of ascorbic acid (AsA) and ascorbic acid 2-phosphate (Asc 2-P), a long-acting vitamin C derivative, on the growth and differentiation of human osteoblast-like cells, we supplemented the culture medium of MG-63 cells with various concentrations (0.25 to 1 mM) of these factors. Asc 2-P significantly stimulated nascent cell growth at all concentrations in the presence of fetal bovine serum (FBS). On the other hand, AsA showed a growth repressive effect depending on its concentration, and that of FBS. Asc 2-P also increased expression of osteoblast differentiation markers, such as collagen synthesis and alkaline phosphatase (ALP) activity. These stimulative activities of Asc 2-P were attenuated by inhibitors of collagen synthesis, indicating that these effects were dependent on collagen synthesis. Electron micrographs of the cells showed the formation of a three-dimensional tissue-like structure endowed with a mature extracellular matrix in the presence of Asc 2-P.
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ABSTRACT: Vitamin C and vitamin E are known as important cellular antioxidants and are involved in several other non-antioxidant processes. Generally vitamin C and vitamin E are not synthesized by humans and therefore have to be applied by nutrition. The absence or deficiency of the vitamins can lead to several dysfunctions and even diseases (e.g. scurvy). The main interest in this study is that vitamin C and E are known to influence bone formation, e.g. vitamin C plays the key role in the synthesis of collagen, the major component of the extracellular bone matrix.In the present study we evaluate the effect of ascorbic acid (vitamin C) and alpha-tocopherol (vitamin E) on the proliferation and differentiation of primary bovine osteoblasts in vitro. Starting from standard growth medium we minimized the foetal calf serum to reduce their stimulatory effect on proliferation.An improved growth and an increased synthesis of the extracellular matrix proteins collagen type I, osteonectin and osteocalcin was observed while increasing the ascorbic acid concentration up to 200 mug/ml. Furthermore the effects of alpha-tocopherol on cell growth and cell differentiation were examined, whereby neither improved growth nor increased synthesis of the extracellular matrix proteins collagen type I, osteonectin and osteocalcin were detected.Further investigations are necessary to target at better supportive effect of vitamins on bone regeneration, and healing.Head & Face Medicine 09/2012; 8(1):25. · 0.98 Impact Factor
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ABSTRACT: INTRODUCTION: Currently, human adipose stem cells (hASCs) are differentiated towards osteogenic lineages using culture medium supplemented with L-ascorbic acid 2-phosphate (AsA2-P), dexamethasone (Dex) and beta-glycerophosphate (beta-GP). Because this osteogenic medium (OM1) was initially generated for the differentiation of bone marrow-derived mesenchymal stem cells, the component concentrations may not be optimal for the differentiation of hASCs. After preliminary screening two efficient osteogenic media (OM2 and OM3) were chosen to be compared with the commonly used osteogenic medium (OM1). To further develop the culture conditions towards clinical usage, the osteo-inductive efficiencies of OM1, OM2 and OM3 were compared using human serum (HS)-based medium and a defined, xeno-free medium (RegES), with fetal bovine serum (FBS)-based medium serving as a control. METHODS: To compare the osteo-inductive efficiency of OM1, OM2 and OM3 in FBS-, HS- and RegES-medium, the osteogenic differentiation was assessed by alkaline phosphatase (ALP) activity, mineralization, and expression of osteogenic marker genes (runx2A, DLX5, collagen type I, osteocalcin, and ALP). RESULTS: In HS-medium, the ALP activity increased significantly by OM3, and mineralization was enhanced by both OM2 and OM3, which have high AsA2-P and low Dex concentrations. ALP activity and mineralization of hASCs was the weakest in FBS-medium, with no significant differences between the OM compositions due to donor variation. However, the qRT-PCR data demonstrated significant up-regulation of runx2A mRNA under osteogenic differentiation in FBS- and HS-medium, particularly by OM3 under FBS conditions. Further, the expression of DLX5 was greatly stimulated by OM1-3 on day 7 when compared to control. The regulation of collagen type I, ALP, and osteocalcin mRNA was modest under induction by OM1-3. The RegES medium was found to support the proliferation and osteogenic differentiation of hASCs, but the composition of the RegES medium hindered the comparison of OM1, OM2 and OM3. CONCLUSIONS: Serum conditions affect hASC proliferation and differentiation significantly. The ALP activity and mineralization was the weakest in FBS-medium, although osteogenic markers were up-regulated on mRNA level. When comparing the OM composition, the commonly used OM1 was least effective. Accordingly, higher concentration of AsA2-P and lower concentration of Dex, as in OM2 and OM3, should be used for the osteogenic differentiation of hASCs in vitro.Stem Cell Research & Therapy 02/2013; 4(1):17. · 3.65 Impact Factor
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ABSTRACT: The multilineage potentiality of cord blood stem cells has been experimentally proven in a number of cell based therapies. Umbilical cord blood (UCB) derived mesenchymal stem cells (MSCs), on prolonged exposure with L-ascorbic acid have been successfully differentiated in to osteoblasts (bone forming cells) without altering the phenotype of the cells. In this case study, the role of L-ascorbic acid on collagen biosynthesis and mineral deposition in MSCs has been assessed, which are ultimately matured in to an insoluble extra cellular matrix (ECM), giving mechanical strength to the bone cells. Moreover, up to specific concentration of L-ascorbic acid (250M), proliferation as well as differentiation po-tential of the cells remains unaltered. Further increase in concentrations of L-ascorbic acid (500 M) reduced the cell pro-liferation and subsequently leads to morphological changes in the cultures. This may be due to an immature antioxidant defense system, which can be overcome by treating the cell cultures with antioxidants. Our final results conclude that L-ascorbic acid has positive effect on the ostogenic differentiation of cord blood stem cells, and the concentration of ascor-bic acid is vital in cell proliferation and differentiation.Current Stem Cell Research & Therapy 01/2013; 8(2):156. · 2.96 Impact Factor