title: Bisphosphonates induce the osteogenic gene expression in co-cultured human endothelial and mesenchymal stem cells.
abstract: Bisphosphonates (BPs) are known to affect bone homeostasis and also to have anti-angiogenic properties. Because of the intimate relationship between angiogenesis and osteogenesis, this study analysed the effects of Alendronate (AL) and Zoledronate (ZL) in the expression of endothelial and osteogenic genes on interacting endothelial and mesenchymal stem cells, an issue that was not previously addressed. Alendronate and ZL, 10(-12) -10(-6) M, were evaluated in a direct co-culture system of human dermal microvascular endothelial cells (HDMEC) and human bone marrow mesenchymal stem cells (HMSC), over a period of 14 days. Experiments with the respective monocultures were run in parallel. Alendronate and ZL caused an initial dose-dependent stimulation in the cell proliferation in the monocultures and co-cultures, and did not interfere with their cellular organization. In HDMEC monocultures, the expression of the endothelial genes CD31, VE-cadherin and VEGFR2 was down-regulated by AL and ZL. In HMSC monocultures, the BPs inhibited VEGF expression, but up-regulated the expression of the osteogenic genes alkaline phosphatase (ALP), bone morphogenic protein-2 (BMP-2) and osteocalcin (OC) and, to a greater extent, osteoprotegerin (OPG), a negative regulator of the osteoclastic differentiation, and increased ALP activity. In co-cultured HDMEC/HMSC, AL and ZL decreased the expression of endothelial genes but elicited an earlier and sustained overexpression of ALP, BMP-2, OC and OPG, compared with the monocultured cells; they also induced ALP activity. This study showed for the first time that AL and ZL greatly induced the osteogenic gene expression on interacting endothelial and mesenchymal stem cells.
authors.affiliation: CECAV, Departamento de Zootecnia, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal; FMDUP, Laboratory for Bone Metabolism and Regeneration, Faculty of Dental Medicine, University of Porto, Porto, Portugal.
authors.forename: Viviana
authors.initials: V
authors.lastname: Ribeiro
authors.forename: Mónica
authors.initials: M
authors.lastname: Garcia
authors.forename: Raquel
authors.initials: R
authors.lastname: Oliveira
authors.forename: Pedro S
authors.initials: PS
authors.lastname: Gomes
authors.forename: Bruno
authors.initials: B
authors.lastname: Colaço
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: Fernandes
mesh_terms: D019386:Alendronate / Q000494:pharmacology*; D000469:Alkaline Phosphatase / Q000378:metabolism; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D004164:Diphosphonates / Q000494:pharmacology*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000378:metabolism*; D055806:Microvessels / Q000166:cytology; D010006:Osteoblasts / Q000378:metabolism; D010012:Osteogenesis / Q000235:genetics; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics / Q000378:metabolism; D000077211:Zoledronic Acid; D014841:von Willebrand Factor / Q000235:genetics / Q000378:metabolism; D000099152:Cadherin 5
chemical_list: D019386:Alendronate; D000469:Alkaline Phosphatase; D015703:Antigens, CD; D050071:Bone Density Conservation Agents; D015820:Cadherins; D004164:Diphosphonates; D007093:Imidazoles; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D040301:Vascular Endothelial Growth Factor Receptor-2; D000077211:Zoledronic Acid; D014841:von Willebrand Factor; D000099152:Cadherin 5; C029417:Von Willebrand antigen; C000588866:KDR protein, human
keywords: Alendronate; Zoledronate; co-cultured cells; endothelial gene expression; human dermal microvascular endothelial cells (HDMEC); human mesenchymal stem cells (HMSC); osteogenic gene expression