title: Smad1/5 and Smad4 expression are important for osteoclast differentiation.
abstract: To investigate the necessity of the canonical BMP pathway during osteoclast differentiation, we created osteoclasts with a conditional gene deletion for Smad1 and Smad5 (SMAD1/5), or Smad4 using adenovirus expressing CRE recombinase (Ad-CRE). Reduction of either Smad4 or Smad1/5 expression resulted in fewer and smaller multinuclear cells compared to control cells. We also detected changes in osteoclast enriched genes, demonstrated by decreased Dc-stamp and cathepsin K expression in both Smad4 and Smad1/5 Ad-CRE osteoclasts, and changes in c-fos and Nfatc1 expression in only Smad4 Ad-CRE cells. Lastly we also detected a significant decrease in resorption pits and area resorbed in both the Smad4 and Smad1/5 Ad-CRE osteoclasts. Because we inhibited osteoclast differentiation with loss of either Smad4 or Smad1/5 expression, we assessed whether BMPs affected osteoclast activity in addition to BMP's effects on differentiation. Therefore, we treated mature osteoclasts with BMP2 or with dorsomorphin, a chemical inhibitor that selectively suppresses canonical BMP signaling. We demonstrated that BMP2 stimulated resorption in mature osteoclasts whereas treatment with dorsomorphin blocks osteoclast resorption. These results indicate that the BMP canonical signaling pathway is important for osteoclast differentiation and activity.
authors.affiliation: Department of Diagnostic and Biological Sciences, University of Minnesota, Minneapolis, Minnesota, 55455.
authors.forename: Amy
authors.initials: A
authors.lastname: Tasca
authors.affiliation: Department of Diagnostic and Biological Sciences, University of Minnesota, Minneapolis, Minnesota, 55455.
authors.forename: Melissa
authors.initials: M
authors.lastname: Stemig
authors.affiliation: Department of Diagnostic and Biological Sciences, University of Minnesota, Minneapolis, Minnesota, 55455.
authors.forename: Aaron
authors.initials: A
authors.lastname: Broege
authors.affiliation: Department of Developmental and Surgical Sciences, University of Minnesota, Minneapolis, Minnesota, 55455.
authors.forename: Brandon
authors.initials: B
authors.lastname: Huang
authors.affiliation: Department of Surgery, University of Minnesota Medical School, Minneapolis, Minnesota, 55455.
authors.forename: Julia
authors.initials: J
authors.lastname: Davydova
authors.affiliation: VIB Center for the Biology of Disease, VIB, KU Leuven Department of Human Genetics, Leuven, 3000, Belgium.
authors.forename: An
authors.initials: A
authors.lastname: Zwijsen
authors.affiliation: Stem Cell Biology and Embryology, KU Leuven, Leuven, 3000, Belgium.
authors.forename: Lieve
authors.initials: L
authors.lastname: Umans
authors.affiliation: Department of Diagnostic and Biological Sciences, University of Minnesota, Minneapolis, Minnesota, 55455.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Jensen
authors.affiliation: Department of Diagnostic and Biological Sciences, University of Minnesota, Minneapolis, Minnesota, 55455.
authors.forename: Raj
authors.initials: R
authors.lastname: Gopalakrishnan
authors.affiliation: Department of Developmental and Surgical Sciences, University of Minnesota, Minneapolis, Minnesota, 55455.
authors.forename: Kim C
authors.initials: KC
authors.lastname: Mansky
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D017353:Gene Deletion; D005786:Gene Expression Regulation; D051379:Mice; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011720:Pyrazoles / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D051898:Smad1 Protein / Q000235:genetics / Q000378:metabolism*; D051901:Smad4 Protein / Q000235:genetics / Q000378:metabolism*; D051902:Smad5 Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011720:Pyrazoles; D011743:Pyrimidines; D051898:Smad1 Protein; C497401:Smad1 protein, mouse; D051901:Smad4 Protein; C490810:Smad4 protein, mouse; D051902:Smad5 Protein; C497798:Smad5 protein, mouse; C516138:dorsomorphin
keywords: BMPs; FUSION; OSTEOCLASTS; RESORPTION; SMADs; TGF-β