Fluid Shear Stress and Raloxifene Stimulates the Proliferation of Osteoblast Through Regulating the Expresstion of β-catenin and Estrogen Receptor α
Abstract
To investigate how the fluid shear stress and raloxifene alone or in combination affect the proliferation of murine pre-osteoblast MC3T3-E1. Methods MC3T3-E1 cells cultured in vitro were treated with the fluid shearing stress and raloxifene alone or in combination, and the MC3T3-E1 cells without treatment were set as control (O group), treated with estrogen receptor antagonist ICI-182780 (10-7 mol/L, I group) were set as negative control group．The cells were observed underoptical inverted microscope from cell shape, size, and nuclear shape to quantity respectively before harvested. The levels of mRNA and protein of β-catenin and estrogen receptor alpha (ERα) were detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot respectively. Results ① As compared with those of the control group and negative control group, the cell proliferation, the expression of ERα mRNA and protein, and protein expression of β-catenin significantly increased in the groups of raloxifene, fluid shearing stress and raloxifene combination fluid shearing stress (P<0.05). RT-PCR analysis showed that the levels of β-catenin mRNA though were not changed significantly in raloxifene group compared with O group (P>0.05), increased significantly in groups of fluid shear stress and raloxifene combination fluid shear stress. ② The cells number, the expression of β-catenin and ERα were not changed significantly between raloxifene group and fluid shearing stress group (P>0.05), but all test parameters in groups of raloxifene combination fluid shearing stress were higher than that of the previous two groups (P<0.05). Conclusion Fluid shear stress and raloxifene, the selective estrogen receptor modulator, were verifed to be able to promote MC3T3-E1 proliferation, increase the expression of β-catenin and ERα, and the combination functioned synergicly significantly. Fluid shear stress and raloxifene may possiblely affect the osteoblast proliferation by regulating the signaling pathways of Wnt/β-catenin and ER.
Keywords: Fluid shear stress, Raloxifene, MC3T3-E1 cells, Estrogen receptor α β-catenin
Full Text:
PDFReferences
Lippuner К. The future of osteoporosis treatment a research update. Swiss Med Wkly,2012; 19(142) : 1-11.
Body JJ, Bergmann P. Boonen S, et al. Evidence-based guidelines for the pharmacological treatment of postmenopausal osteoporosis;a consensus document by the Belgian Bone Club. Osteoporos Int.2010;21(10):1657-1680.
Sliwinski L. Folwarczna J, Nowinska B, et al. A comparative study of the effects of genistein, estradiol and raloxifene on the murine skeletal system. Acta Biochim Pol, 2009;56 ( 2 ); 261- 270.
Pruitt LA. Weight-training effects on bone mineral density in early postmenopausal. J Bone Miner Res. 1992;7(2): 179 -185.
Lidan Y, Sara T, Sean RC, et al. Bone cells grown on micropatterned surfaces are more sensitive to fluid shear stress. Cell Mol Bioeng,2008; 1 (3): 182-188.
Smalt R.Mitchell FT, Howard RL, et al. Induction of NO and prostaglandin E2 in osteoblasts by wall-shear stress but not mechanical strain. Am J Physiol, 1997; 273 (4 Pt 1); E751- E758.
Shivaram GM.Kim CH.Batra NN, et al. Novel early response genes in osteoblasts exposed to dynamic fluid flow. Philos Transact A Math Phys Eng Sci,2010;368( 1912);605-616.
Weinbaum S. Cowin SC, Zeng Y. A model for excitation of osteocytes by mechanical loading induced bone fluid shear stress. J Biomech, 1994 ;27(3):339-360.
You J. Yellowley CE, Donahue HJ, et al. Substrate deformation levels associated with routine physical activity are less stimulatory to bone cells relative to loading-induced oscillatory fluid flow. J Biomech Eng.2000; 122(4):387-393.
MacDonald В T,Tamai K.He X. Wnt/beta-catenin signaling; components, mechanisms, and diseases . Dev Cell. 2009; 17 ( 1) : 9-26.
Cheng MZ, Zaman G, Rawlinson SCF, et al. Mechanical loading and sex hormone interactions in organ cultures of rat ulna. J Bone Miner Res, 1996; 11 (4) ;502-511.
Gennari L. Merlotti D. Valleggi F. et al. Selecture estrogen receptor modulators for postmenopausal osteoporosis: current state of development. Drugs Aging, 2007;24(5);361-379.
Recker RR, Mitlak BH, Ni X, et al. Long-term raloxifene for postmenopausal osteoporosis. Curr Med Res Opin, 2011; 27 (9):1755-1761.
Olivier S, Fillet M, Malaise M. et al. Sodium nitroprusside- induced osteoblast apoptosis is mediated by long chain ceramide and is decreased by raloxifene. Biochem Pharmacol ,2005; 69 (6);891-901.
Green S, Walter P. Kumar V, et al. Human estrogen receptor cDNA:sequence, expression and homology to verbA. Nature , 1986(3);320:134 -139.
Paulmurugan R, Tamrazi A, Massoud TF, et al. In vitro and in -vivo molecular imaging of estrogen receptor a and ,3 homo- and heterodimerization: exploration of new modes of receptor regulation. Mol Endocrinol,2011 ;25( 12);2029-2040.
Pineda B, Hermenegildo C, Tarin JJ, et al. Effects of administration of hormone therapy or raloxifene on the immune system and on biochemical markers of bone remodeling. Menopause,2012; 19(3);319-327.
Chung Y E. Lee S H, Lee S Y, et al. Long-term treatment with raloxifene, but not bisphosphonates, reduces circulating sclerostin levels in postmenopausal women . Osteoporos Int, 2011;10(1) :52-61.
Refbacks
- There are currently no refbacks.
