2008, Number 6
Rev Invest Clin 2008; 60 (6)
Aguilar-Vázquez R, Carballo-Molina OA, Collazo-Navarrete O, Guerrero-Rangel M, Saucedo-Campos AD, Barrera-Lechuga P, López-Marure R, Cáceres-Cortés JR
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ABSTRACTIntroduction. Mesenchymal stem cells have the potential to differentiate into several types of cells including osteoblasts. These stem cells have cell surface markers found on cells of endothelial and subendothelial origin of the umbilical cord vein. Taking this into consideration we have postulated that human umbilical vein endothelial cells (HUVEC) could present osteogenic differentiation as well. Gene activation that could drive osteogenic differentiation is regulated by exogenous and endogenous factors. Objective. The induction osteogenesis in HUVEC. Material and methods. We used: a) an osteogenic medium containing 0.1 µM dexamethasone, 10 µM β-glycerophosphate, 50 µM L-ascorbic-acid 2-phosphate, 20% MCGS serum; and b) a treatment with DNA demethylating agents hydralazine and 5'-aza-2'-deoxycytidine (0.39-200 µM). Phenotypic characteristics of HUVEC were their spindle and stellate shapes with fine homogenous cytoplasm, typically associated with fibroblast-like cells. Results. The control cells (without osteogenic treatment) exhibited little extracellular matrix, whereas the osteogenically treated cells appeared shortened and flattened, and they were surrounded by extracellular matrix that subsequently became mineralized in vitro. After 28 days in culture, morphologic and histochemical stu-dies confirmed that osteogenic medium had a strong stimulatory effect on the alkaline phosphatase activity of endothelial cells, a very early marker of cell differentiation into the osteogenic lineage. Hydralazine and 5'-aza-2'-deoxycytidine, two drugs utilized in chromatin remodeling leading to gene re-expression of inactivated DNA hypermethylated islands, did not favor osteoblast differentiation. Conclusion. Our study shows that HUVEC can differentiate along an osteogenic li-neage and thus provide an alternative source for cell-based therapies and tissue engineering strategies.