Abstract
Intermittent parathyroid hormone (PTH) administration shows an anabolic effect on bone. However, the mechanisms are not fully studied. Recent studies suggest that Wnt signaling is involved in PTH-induced bone formation. The current study was to examine if Wnt/β-catenin pathway is required during PTH-induced osteoblast differentiation. Osteoblastic MC3T3-E1 cells were treated with human PTH (1-34) (hPTH [1-34]) and expression levels of osteoblast differentiation markers were detected by real-time PCR. RNA levels of β-catenin, Runx2, Osteocalcin, Alkaline phosphatase, and Bone sialoprotein were significantly up-regulated after treatment with 10−8 M of hPTH (1-34) for 6 h. Alkaline phosphatase activity and protein expression of β-catenin were also increased after 6 days of intermittent treatment with hPTH (1-34) in MC3T3-E1 cells. hPTH (1-34) significantly enhanced Topflash Luciferase activity after 6 h of treatment. More important, PTH-induced Alkaline phosphatase activity was significantly inhibited by knocking down β-catenin expression in cells using siRNA. Real-time RT-PCR results further showed down regulation of Runx2, Osteocalcin, Alkaline phosphatase, Bone sialoprotein gene expression in β-catenin siRNA transfected cells with/without PTH treatment. These results clearly indicate that PTH stimulates Wnt/β-catenin pathway in MC3T3-E1 cells and osteoblast differentiation markers expression was up-regulated by activation of Wnt/β-catenin signaling. Our study demonstrated that PTH-induced osteoblast differentiation mainly through activation of Wnt/β-catenin pathway in osteoblastic MC3T3-E1 cells.
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References
Ebeling PR, Jones JD, Burritt MF, Duerson CR, Lane AW, Hassager C, Kumar R, Riggs BL (1992) Skeletal responsiveness to endogenous parathyroid hormone in postmenopausal osteoporosis. J Clin Endocrinol Metab 75:1033–1038
Shen V, Dempster DW, Birchman R, Xu R, Lindsay R (1993) Loss of cancellous bone mass and connectivity in ovariectomized rats can be restored by combined treatment with parathyroid hormone and estradiol. J Clin Invest 91:2479–2487
Turner RT, Evans GL, Cavolina JM, Halloran B, Morey-Holton E (1998) Programmed administration of parathyroid hormone increases bone formation and reduces bone loss in hindlimb-unloaded ovariectomized rats. Endocrinology 139:4086–4091
Mosekilde L, Tornvig L, Thomsen JS, Orhii PB, Banu MJ, Kalu DN (2000) Parathyroid hormone and growth hormone have additive or synergetic effect when used as intervention treatment in ovariectomized rats with established osteopenia. Bone 26:643–651
Koh AJ, Demiralp B, Neiva KG, Hooten J, Nohutcu RM, Shim H, Datta NS, Taichman RS, McCauley LK (2005) Cells of the osteoclast lineage as mediators of the anabolic actions of parathyroid hormone in bone. Endocrinology 146:4584–4596
Samadfam R, Xia Q, Miao D, Hendy GN, Goltzman D (2008) Exogenous PTH and endogenous 1,25-dihydroxyvitamin D are complementary in inducing an anabolic effect on bone. J Bone Miner Res 23:1257–1266
Vehaar HJ, Lems WF (2010) PTH analogues and osteoporotic fractures. Expert Opin Biol Ther 10:1387–1394
Ejersted C, Andreassen TT, Oxlund H, Jorgensen PH, Bak B, Haggblad J, Torring O, Nilsson MH (1993) Human parathyroid hormone (1-34) and (1-84) increase the mechanical strength and thickness of cortical bone in rats. J Bone Miner Res 8:1097–1101
Schmidt IU, Dobnig H, Turner RT (1995) Intermittent parathyroid hormone treatment increases osteoblast number, steady state messenger ribonucleic acid levels for osteocalcin, and bone formation in tibial metaphysis of hypophysectomized female rats. Endocrinology 136:5127–5134
Jouishomme H, Whitfield JF, Gagnon L, Maclean S, Isaacs R, Chakravarthy B, Durkin J, Neugebauer W, Willick G, Rixon RH (1994) Further definition of the protein kinase C activation domain of the parathyroid hormone. J Bone Miner Res 9:943–949
Radeff JM, Nagy Z, Stern PH (2004) Rho and Rho kinase are involved in parathyroid hormone-stimulated protein kinase C alpha translocation and IL-6 promoter activity in osteoblastic cells. J Bone Miner Res 19:1882–1891
Dong YF, Drissi H, Chen M, Chen D, Zuscik MJ, Schwarz EM, O’Keefe RJ (2005) Wnt-mediated regulation of chondrocyte maturation: modulation by TGF-beta. J Cell Biochem 95:1057–1068
Dong YF, Soung do Y, Schwarz EM, O’Keefe RJ, Drissi H (2006) Wnt induction of chondrocyte hypertrophy through the Runx2 transcription factor. J Cell Physiol 208:77–86
Komori T (2011) Signaling networks in RUNX2-dependent bone development. J Cell Biochem 112:750–755
Ikeda S, Kishida S, Yamamoto H, Murai H, Koyama S, Kikuchi A (1998) Axin, a negative regulator of the Wnt signaling pathway, forms a complex with GSK-3beta and beta-catenin and promotes GSK-3beta-dependent phosphorylation of beta-catenin. EMBO J 17:1371–1384
Day TF, Guo X, Garrett-Beal L, Yang Y (2005) Wnt/beta-catenin signaling in mesenchymal progenitors controls osteoblast and chondrocyte differentiation during vertebrate skeletogenesis. Dev Cell 8:739–750
Hu H, Hilton MJ, Tu X, Yu K, Ornitz DM, Long F (2005) Sequential roles of Hedgehog and Wnt signaling in osteoblast development. Development 132:49–60
Romero G, Sneddon WB, Yang Y, Wheeler D, Blair HC, Friedman PA (2010) Parathyroid hormone receptor directly interacts with dishevelled to regulate beta-Catenin signaling and osteoclastogenesis. J Biol Chem 285:14756–14763
Guo J, Liu M, Yang D, Bouxsein ML, Saito H, Galvin RJ, Kuhstoss SA, Thomas CC, Schipani E, Baron R, Bringhurst FR, Kronenberg HM (2010) Suppression of Wnt signaling by Dkk1 attenuates PTH-mediated stromal cell response and new bone formation. Cell Metab 11:161–171
Ishizuya T, Yokose S, Hori M, Noda T, Suda T, Yoshiki S, Yamaguchi A (1997) Parathyroid hormone exerts disparate effects on osteoblast differentiation depending on exposure time in rat osteoblastic cells. J Clin Invest 99:2961–2970
Nishida S, Yamaguchi A, Tanizawa T, Endo N, Mashiba T, Uchiyama Y, Suda T, Yoshiki S, Takahashi HE (1994) Increased bone formation by intermittent parathyroid hormone administration is due to the stimulation of proliferation and differentiation of osteoprogenitor cells in bone marrow. Bone 15:717–723
Dobnig H, Turner RT (1995) Evidence that intermittent treatment with parathyroid hormone increases bone formation in adult rats by activation of bone lining cells. Endocrinology 136:3632–3638
Krishnan V, Moore TL, Ma YL, Helvering LM, Frolik CA, Valasek KM, Ducy P, Geiser AG (2003) Parathyroid hormone bone anabolic action requires Cbfa1/Runx2-dependent signaling. Mol Endocrinol 17:423–435
Radeff JM, Singh AT, Stern PH (2004) Role of protein kinase A, phospholipase C and phospholipase D in parathyroid hormone receptor regulation of protein kinase Calpha and interleukin-6 in UMR-106 osteoblastic cells. Cell Signal 16:105–114
Kaiser E, Sato M, Onyia JE, Chandrasekhar S (2001) Parathyroid hormone (1-34) regulates integrin expression in vivo in rat osteoblasts. J Cell Biochem 83:617–630
Tobimatsu T, Kaji H, Sowa H, Naito J, Canaff L, Hendy GN, Sugimoto T, Chihara K (2006) Parathyroid hormone increases beta-catenin levels through Smad3 in mouse osteoblastic cells. Endocrinology 147:2583–2590
Acknowledgments
We are grateful to Anthony Mirando for his contributions to prepare this manuscript. We thank the Research Grant awarded by Ministry of Science and Technology in Liaoning Province, China for partial funding support.
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Tian, Y., Xu, Y., Fu, Q. et al. Parathyroid hormone regulates osteoblast differentiation in a Wnt/β-catenin-dependent manner. Mol Cell Biochem 355, 211–216 (2011). https://doi.org/10.1007/s11010-011-0856-8
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DOI: https://doi.org/10.1007/s11010-011-0856-8