The small peptide OGP(10-14) acts through Src kinases and RhoA pathways in Mo-7e cells: morphologic and immunologic evaluation.
ABSTRACT Osteogenic growth peptide (OGP) is an endogenous tetradecapeptide present in micromolar concentrations in mammalian serum; its carboxy-terminal pentapeptide, OGP(10-14), represents its physiologically active fragment. OGP(10-14) induces proliferation and differentiation in fibroblast and osteoblast cell lines, and it enhances hematopoiesis in vitro and in vivo. The signaling pathways triggered by OGP(10-14) are not yet fully known. In the present report, we evaluated the effect of OGP(10-14) on differentiation of a cancer megakaryoblast cell line and its involvement on RhoA and Src family kinases signaling pathway.
Cell proliferation of the Mo-7e line was evaluated using the MTT test. Mo-7e differentiation was evaluated by microscopic observation of cell morphology and by expression of the factor VIII-related antigen. Involvement of RhoA and Src kinases on signaling pathways triggered by OGP(10-14) was analyzed using RhoA and Src family kinase (SFK) inhibitors (C3 and PP2) and an immunoperoxidase technique.
OGP(10-14) induces expression of the factor VIII-related antigen, morphologic changes indicative of megakaryocytic differentiation, and a down-regulation of the Fyn Src kinase. These OGP(10-14) effects were prevented by C3 and enhanced by PP2.
The anti-proliferative and pro-differentiating activities of OGP(10-14) on thrombopoietin (TPO)-primed Mo-7e cells are mediated by RhoA and Src kinase pathways as demonstrated by the use of C3 and PP2.
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ABSTRACT: Human mesenchymal stem cells (MSC) are currently recognized as a powerful cell source for regenerative medicine, notably for their capacity to differentiate into multiple cell types. The combination of MSC with biomaterials functionalized with instructive cues can be used as a strategy to direct specific lineage commitment, and thus improve the therapeutic efficacy of these cells. In terms of biomaterial design, one common approach is the functionalization of materials with ligands capable of directly binding to cell receptors and trigger specific differentiation signaling pathways. Other strategies focus on the use of moieties that have an indirect effect, acting for example as sequesters of bioactive ligands present in the extracellular milieu that will in turn interact with cells. Compared with complex biomolecules, the use of simple compounds such as chemical-moieties, peptides, and other small molecules can be advantageous by leading to less expensive and easily tunable biomaterial formulations. This review describes different strategies that have been used to promote substrate-mediated guidance of osteogenic differentiation of immature osteoblasts, osteoprogenitors and MSC, through chemically conjugated small moieties, both in 2D and 3D set-ups. In each case, the selected moiety the coupling strategy and the main findings of the study were highlighted. The latest advances and future perspectives in the field are also discussed.Acta biomaterialia 08/2013; 9(11). DOI:10.1016/j.actbio.2013.08.004 · 5.68 Impact Factor
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ABSTRACT: In this study, we report the use of surface immobilized peptide concentration gradient technology to characterize MC3T3-E1 osteoblast cell response to osteogenic growth peptide (OGP), a small peptide found naturally in human serum at mumol/L concentrations. OGP was coupled to oxidized self assembled monolayer (SAM) gradients by a polyethylene oxide (PEO) linker using click chemistry. After 4h incubation with MC3T3-E1 cells, OGP functionalized surfaces had higher cell attachment at low peptide concentrations compared to control gradients. By day 3, OGP gradient substrates had higher cell densities compared to control gradients at all concentrations. MC3T3-E1 cell doubling time was 35% faster on OGP substrates relative to SAM gradients alone, signifying an appreciable increase in cell proliferation. This increase in cell proliferation, or decrease in doubling time, due to OGP peptide was reduced by day 7. Hence, immobilized OGP increased cell proliferation from 0 days to 3 days at all densities indicating it may be useful as a proliferative peptide that can be used in tissue engineering substrates.Biomaterials 11/2009; 31(7):1604-11. DOI:10.1016/j.biomaterials.2009.11.011 · 8.31 Impact Factor
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ABSTRACT: The outcome of cell-based therapies can benefit from carefully designed cell carriers. A multifunctional injectable vehicle for the co-delivery of human mesenchymal stem cells (hMSC) and osteoinductive peptides is proposed, to specifically direct hMSC osteogenic differentiation. The osteogenic growth peptide (OGP) inspired the design of two peptides, where the bioactive portion of OGP was flanked by a protease-sensitive linker, or its scrambled sequence, to provide faster and slower release rates, respectively. Peptides were fully characterized and chemically grafted to alginate. Both OGP analogues released bioactive fragments in vitro, at different kinetics, which stimulated hMSC proliferation and osteogenesis. hMSC-laden OGP-alginate hydrogels were tested at an ectopic site in a xenograft mouse model. After 4weeks, OGP-alginate hydrogels were more degraded and colonized by vascularized connective tissue than the control (without OGP). hMSC were able to proliferate, migrate outward the hydrogels, produce endogenous extracellular matrix and mineralize it. Moreover, OGP-groups stimulated hMSC osteogenesis, as compared with the control. Overall, the ability of the proposed platform to direct the fate of transplanted hMSC in loco was demonstrated, and OGP-releasing hydrogels emerged as a potentially useful system to promote bone regeneration.Journal of Controlled Release 06/2014; DOI:10.1016/j.jconrel.2014.06.030 · 7.26 Impact Factor