title: Reduction by strontium of the bone marrow adiposity in mice and repression of the adipogenic commitment of multipotent C3H10T1/2 cells.
abstract: Multipotent mesenchymal cells (MMCs) differentiate into osteoblasts or adipocytes through RUNX2 and PPARγ2, respectively. Strontium ranelate has been shown to promote osteoblastogenesis and prevent adipogenesis in long-term experiments using MMCs. The present study involved in-vitro and in-vivo investigations of whether Sr might first be an inhibitor of adipogenesis, thus explaining late osteoblastogenesis. It was established in vivo that Sr reduces adipogenesis in mice treated only for 3 weeks with a 6 mmol/kg/day dose of Sr while the trabecular bone volume is increased. In order to decipher molecular mechanisms during inhibition of adipogenesis, we used murine MMCs C3H10T1/2 cultured under adipogenic conditions (AD) and treated Sr of a concentration up to 3 mM. It was shown that early on (day 1), Sr dose-dependently reduced PPARγ2 and CEBPα mRNA without affecting the RUNX2 gene expression whereas it repressed ALP mRNA. Later (day 5), PPARγ2 and CEBPα mRNA remained inhibited by Sr, preventing adipocyte lipid accumulation, while Runx2 and ALP mRNA were increased. Moreover, under the mentioned conditions, Sr was able to quickly induce the Cyclin D1 gene expression, proliferation and fibronectin fibrillogenesis, both involved in the inhibition of adipogenesis. The inhibition of the ERK pathway by U0126 blunted the Sr-induced PPARγ2 repression while restoring the lipid accumulation. These results demonstrated that Sr was capable of rapidly reducing adipogenesis by a selective PPARγ2 repression that can be explained by its ability to promote MMC proliferation.
authors.affiliation: INSERM U1059, F42023, Saint-Etienne France.
authors.forename: C
authors.initials: C
authors.lastname: Fournier
authors.forename: A
authors.initials: A
authors.lastname: Perrier
authors.forename: M
authors.initials: M
authors.lastname: Thomas
authors.forename: N
authors.initials: N
authors.lastname: Laroche
authors.forename: V
authors.initials: V
authors.lastname: Dumas
authors.forename: A
authors.initials: A
authors.lastname: Rattner
authors.forename: L
authors.initials: L
authors.lastname: Vico
authors.forename: A
authors.initials: A
authors.lastname: Guignandon
mesh_terms: D050156:Adipogenesis / Q000187:drug effects* / Q000235:genetics; D050154:Adiposity / Q000187:drug effects* / Q000235:genetics; D000818:Animals; D001853:Bone Marrow / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D001842:Bone and Bones / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000187:drug effects; D002070:Butadienes / Q000494:pharmacology; D019070:Cell Lineage / Q000187:drug effects* / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D051379:Mice; D039902:Multipotent Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D009570:Nitriles / Q000494:pharmacology; D009929:Organ Size / Q000187:drug effects; D047495:PPAR gamma / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011859:Radiography; D000077154:Rosiglitazone; D013324:Strontium / Q000494:pharmacology*; D045162:Thiazolidinediones / Q000494:pharmacology
chemical_list: D002070:Butadienes; D005353:Fibronectins; D009570:Nitriles; D047495:PPAR gamma; D012333:RNA, Messenger; D045162:Thiazolidinediones; C113580:U 0126; D000077154:Rosiglitazone; D019938:Cyclin D1; D048049:Extracellular Signal-Regulated MAP Kinases; D013324:Strontium