Leptin effect on RANKL and OPG expression in MC3T3-E1 osteoblasts.
Recent studies have suggested that leptin hormone may play a pivotal role on bone remodeling through a direct effect by modulating positively the OPG/RANKL balance. Here, we investigate the effect of leptin hormone on RANKL and OPG expression in MC3T3-E1 osteoblasts using RT-PCR and ELISA measurements. We have at first identified the expression of Ob-Rb and Ob-Ra leptin receptor isoforms in MC3T3-E1 and observed that these cells respond to mrleptin treatments. We then investigated the effect of mrleptin on RANKL and OPG expression. We show that mrleptin dose-dependently regulated the expression of RANKL mRNA with complete inhibition observed at concentrations higher than 12 ng/ml. This effect was confirmed with sRANKL protein measurements. However, the exposure of MC3T3-E1 to mrleptin had no effect on OPG mRNA. Taken together, these results suggest that leptin modulates positively OPG/RANKL balance by inhibiting the expression of RANKL gene.
Lamghari
M
M
INEB-Instituto de Engenharia Biomédica, Laboratório de Biomateriais, Rua Campo Alegre 823, 4150-180 Porto, Portugal. lamghari@ineb.up.pt
Tavares
L
L
Camboa
N
N
Barbosa
M A
MA
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D015870:Gene Expression; D006023:Glycoproteins / Q000235:genetics*; D020738:Leptin / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism*; D053244:Osteoprotegerin; D053245:RANK Ligand; D012333:RNA, Messenger / Q000235:genetics; D053246:Receptor Activator of Nuclear Factor-kappa B; D011956:Receptors, Cell Surface / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics*; D054411:Receptors, Leptin; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics*
D002352:Carrier Proteins; D006023:Glycoproteins; D020738:Leptin; D008562:Membrane Glycoproteins; D053244:Osteoprotegerin; D053245:RANK Ligand; D012333:RNA, Messenger; D053246:Receptor Activator of Nuclear Factor-kappa B; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D054411:Receptors, Leptin; D018124:Receptors, Tumor Necrosis Factor; C505687:Tnfrsf11a protein, mouse; C506031:Tnfrsf11b protein, mouse; C505689:Tnfsf11 protein, mouse; C515447:leptin receptor, mouse; D000469:Alkaline Phosphatase