title: Thiazolidinedione-induced lipid droplet formation during osteogenic differentiation.
abstract: Chronic administration of the insulin-sensitising drugs, thiazolidinediones (TZDs), results in low bone mineral density and 'fatty bones'. This is thought to be due, at least in part, to aberrant differentiation of progenitor mesenchymal stem cells (MSCs) away from osteogenesis towards adipogenesis. This study directly compared the effects of rosiglitazone, pioglitazone, and netoglitazone treatment on osteogenesis and adipogenesis in MSCs derived from subcutaneous (SC) or visceral (PV) white adipose tissue. MSCs were isolated from adipose tissue depots of male Wistar rats and characterised using flow cytometry. The effects of TZD treatment on osteogenic and adipogenic differentiation were assessed histologically (day 14) and by quantitative PCR analysis (Pparγ2 (Pparg2), Ap2 (Fabp4), Adipsin (Adps), Msx2, Collagen I (Col1a1), and Alp) on days 0, 7, and 10. Uniquely, lipid droplet formation and mineralisation were found to occur concurrently in response to TZD treatment during osteogenesis. Compared with SC MSCs, PV MSCs were more prone to lipid accumulation under controlled osteogenic and adipogenic differentiation conditions. This study demonstrated that the extent of lipid accumulation is dependent on the nature of the Ppar ligand and that SC and PV MSCs respond differently to in vitro TZD treatment, suggesting that metabolic status can contribute to the adverse effects associated with TZD treatment.
authors.affiliation: Division of EndocrinologyDepartment of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 19063, Tygerberg 7505, South Africa.
authors.forename: M
authors.initials: M
authors.lastname: van de Vyver
authors.affiliation: Division of EndocrinologyDepartment of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 19063, Tygerberg 7505, South Africa.
authors.forename: E
authors.initials: E
authors.lastname: Andrag
authors.affiliation: Division of EndocrinologyDepartment of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 19063, Tygerberg 7505, South Africa.
authors.forename: I L
authors.initials: IL
authors.lastname: Cockburn
authors.affiliation: Division of EndocrinologyDepartment of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 19063, Tygerberg 7505, South Africa wferris@sun.ac.za.
authors.forename: W F
authors.initials: WF
authors.lastname: Ferris
mesh_terms: D017667:Adipocytes / Q000187:drug effects / Q000502:physiology; D050156:Adipogenesis / Q000187:drug effects; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D066292:Lipid Droplets / Q000187:drug effects* / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000502:physiology; D010012:Osteogenesis / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D045162:Thiazolidinediones / Q000494:pharmacology*
chemical_list: D045162:Thiazolidinediones
keywords: mesenchymal stem cells; netoglitazone; pioglitazone; rosiglitazone