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Volumn 126, Issue 23, 2013, Pages 5391-5399

A synthetic nanofibrillar matrix promotes in vitro hepatic differentiation of embryonic stem cells and induced pluripotent stem cells

Author keywords

Embryonic stem cells; Hepatic differentiation; In vitro differentiation; Induced pluripotent stem cells

Indexed keywords

NANOFIBER; RAC1 PROTEIN;

EID: 84890141367     PISSN: 00219533     EISSN: 14779137     Source Type: Journal    
DOI: 10.1242/jcs.129767     Document Type: Article
Times cited : (34)

References (53)
  • 2
    • 34247168648 scopus 로고    scopus 로고
    • Functional nanofiber scaffolds with different spacers modulate adhesion and expansion of cryopreserved umbilical cord blood hematopoietic stem/progenitor cells
    • Chua, K.-N., Chai, C., Lee, P.-C., Ramakrishna, S., Leong, K. W. and Mao, H.-Q. (2007). Functional nanofiber scaffolds with different spacers modulate adhesion and expansion of cryopreserved umbilical cord blood hematopoietic stem/progenitor cells. Exp. Hematol. 35, 771-781.
    • (2007) Exp. Hematol. , vol.35 , pp. 771-781
    • Chua, K.-N.1    Chai, C.2    Lee, P.-C.3    Ramakrishna, S.4    Leong, K.W.5    Mao, H.-Q.6
  • 3
    • 33845351678 scopus 로고    scopus 로고
    • Wnt signalling in the mouse intestine
    • Clarke, R. (2006). Wnt signalling in the mouse intestine. Oncogene 25, 7512-7521.
    • (2006) Oncogene , vol.25 , pp. 7512-7521
    • Clarke, R.1
  • 6
    • 17144464384 scopus 로고    scopus 로고
    • Recombinant human laminin-10 (alpha5beta 1 gamma1). Production, purification, and migrationpromoting activity on vascular endothelial cells
    • Doi, M., Thyboll, J., Kortesmaa, J., Jansson, K., Iivanainen, A., Parvardeh, M., Timpl, R., Hedin, U., Swedenborg, J. and Tryggvason, K. (2002). Recombinant human laminin-10 (alpha5beta1gamma1). Production, purification, and migrationpromoting activity on vascular endothelial cells. J. Biol. Chem. 277, 12741-12748.
    • (2002) J. Biol. Chem , vol.277 , pp. 12741-12748
    • Doi, M.1    Thyboll, J.2    Kortesmaa, J.3    Jansson, K.4    Iivanainen, A.5    Parvardeh, M.6    Timpl, R.7    Hedin, U.8    Swedenborg, J.9    Tryggvason, K.10
  • 7
    • 2442664118 scopus 로고    scopus 로고
    • Rational design and characterization of a Rac GTPase-specific small molecule inhibitor
    • Gao, Y., Dickerson, J. B., Guo, F., Zheng, J. and Zheng, Y. (2004). Rational design and characterization of a Rac GTPase-specific small molecule inhibitor. Proc. Natl. Acad. Sci. USA 101, 7618-7623.
    • (2004) Proc. Natl. Acad. Sci. USA , vol.101 , pp. 7618-7623
    • Gao, Y.1    Dickerson, J.B.2    Guo, F.3    Zheng, J.4    Zheng, Y.5
  • 8
    • 77950584190 scopus 로고    scopus 로고
    • Stem cell shape regulates a chondrogenic versus myogenic fate through Rac1 and N-cadherin
    • Gao, L., McBeath, R. and Chen, C. S. (2010). Stem cell shape regulates a chondrogenic versus myogenic fate through Rac1 and N-cadherin. Stem Cells 28, 564-572.
    • (2010) Stem Cells , vol.28 , pp. 564-572
    • Gao, L.1    McBeath, R.2    Chen, C.S.3
  • 9
    • 84859910748 scopus 로고    scopus 로고
    • Hepatic differentiation from human mesenchymal stem cells on a novel nanofiber scaffold
    • Ghaedi, M., Soleimani, M., Shabani, I., Duan, Y. and Lotfi, A. S. (2012). Hepatic differentiation from human mesenchymal stem cells on a novel nanofiber scaffold. Cell. Mol. Biol. Lett. 17, 89-106.
    • (2012) Cell. Mol. Biol. Lett. , vol.17 , pp. 89-106
    • Ghaedi, M.1    Soleimani, M.2    Shabani, I.3    Duan, Y.4    Lotfi, A.S.5
  • 11
    • 80051546418 scopus 로고    scopus 로고
    • The promotion of stemness and pluripotency following feeder-free culture of embryonic stem cells on collagen-grafted 3-dimensional nanofibrous scaffold
    • Hashemi, S. M., Soudi, S., Shabani, I., Naderi, M. and Soleimani, M. (2011). The promotion of stemness and pluripotency following feeder-free culture of embryonic stem cells on collagen-grafted 3-dimensional nanofibrous scaffold. Biomaterials 32, 7363-7374.
    • (2011) Biomaterials , vol.32 , pp. 7363-7374
    • Hashemi, S.M.1    Soudi, S.2    Shabani, I.3    Naderi, M.4    Soleimani, M.5
  • 12
    • 50149083752 scopus 로고    scopus 로고
    • Mammalian Rho GTPases: new insights into their functions from in vivo studies
    • Heasman, S. J. and Ridley, A. J. (2008). Mammalian Rho GTPases: new insights into their functions from in vivo studies. Nat. Rev. Mol. Cell Biol. 9, 690-701.
    • (2008) Nat. Rev. Mol. Cell Biol. , vol.9 , pp. 690-701
    • Heasman, S.J.1    Ridley, A.J.2
  • 13
    • 0035813106 scopus 로고    scopus 로고
    • Rac1 inhibits myogenic differentiation by preventing the complete withdrawal of myoblasts from the cell cycle
    • Heller, H., Gredinger, E. and Bengal, E. (2001). Rac1 inhibits myogenic differentiation by preventing the complete withdrawal of myoblasts from the cell cycle. J. Biol. Chem. 276, 37307-37316.
    • (2001) J. Biol. Chem. , vol.276 , pp. 37307-37316
    • Heller, H.1    Gredinger, E.2    Bengal, E.3
  • 16
    • 0033580985 scopus 로고    scopus 로고
    • Initiation of mammalian liver development from endoderm by fibroblast growth factors
    • Jung, J. (1999). Initiation of mammalian liver development from endoderm by fibroblast growth factors. Science 284, 1998-2003.
    • (1999) Science , vol.284 , pp. 1998-2003
    • Jung, J.1
  • 18
    • 74549134528 scopus 로고    scopus 로고
    • Embryonic and adult stem cell systems in mammals: ontology and regulation
    • Katsumoto, K., Shiraki, N., Miki, R. and Kume, S. (2010). Embryonic and adult stem cell systems in mammals: ontology and regulation. Dev. Growth Differ. 52, 115-129.
    • (2010) Dev. Growth Differ. , vol.52 , pp. 115-129
    • Katsumoto, K.1    Shiraki, N.2    Miki, R.3    Kume, S.4
  • 19
    • 58849147591 scopus 로고    scopus 로고
    • Biochemical and molecular characterization of hepatocyte-like cells derived from human bone marrow mesenchymal stem cells on a novel three-dimensional biocompatible nanofibrous scaffold
    • Kazemnejad, S., Allameh, A., Soleimani, M., Gharehbaghian, A., Mohammadi, Y., Amirizadeh, N. and Jazayery, M. (2009). Biochemical and molecular characterization of hepatocyte-like cells derived from human bone marrow mesenchymal stem cells on a novel three-dimensional biocompatible nanofibrous scaffold. J. Gastroenterol. Hepatol. 24, 278-287.
    • (2009) J. Gastroenterol. Hepatol. , vol.24 , pp. 278-287
    • Kazemnejad, S.1    Allameh, A.2    Soleimani, M.3    Gharehbaghian, A.4    Mohammadi, Y.5    Amirizadeh, N.6    Jazayery, M.7
  • 21
    • 57749093010 scopus 로고    scopus 로고
    • Retinoic acid leads to cytoskeletal rearrangement through AMPK-Rac1 and stimulates glucose uptake through AMPK-p38 MAPK in skeletal muscle cells
    • Lee, Y. M., Lee, J. O., Jung, J.-H., Kim, J. H., Park, S.-H., Park, J. M., Kim, E.-K., Suh, P.-G. and Kim, H. S. (2008). Retinoic acid leads to cytoskeletal rearrangement through AMPK-Rac1 and stimulates glucose uptake through AMPK-p38 MAPK in skeletal muscle cells. J. Biol. Chem. 283, 33969-33974.
    • (2008) J. Biol. Chem. , vol.283 , pp. 33969-33974
    • Lee, Y.M.1    Lee, J.O.2    Jung, J.-H.3    Kim, J.H.4    Park, S.-H.5    Park, J.M.6    Kim, E.-K.7    Suh, P.-G.8    Kim, H.S.9
  • 22
    • 77954394980 scopus 로고    scopus 로고
    • The rho GTPase Rac1 is required for proliferation and survival of progenitors in the developing forebrain
    • Leone, D. P., Srinivasan, K., Brakebusch, C. and McConnell, S. K. (2010). The rho GTPase Rac1 is required for proliferation and survival of progenitors in the developing forebrain. Dev. Neurobiol. 70, 659-678.
    • (2010) Dev. Neurobiol. , vol.70 , pp. 659-678
    • Leone, D.P.1    Srinivasan, K.2    Brakebusch, C.3    McConnell, S.K.4
  • 23
    • 70349810887 scopus 로고    scopus 로고
    • Electrospun scaffolds for stem cell engineering
    • Lim, S. H. and Mao, H.-Q. (2009). Electrospun scaffolds for stem cell engineering. Adv. Drug Deliv. Rev. 61, 1084-1096.
    • (2009) Adv. Drug Deliv. Rev. , vol.61 , pp. 1084-1096
    • Lim, S.H.1    Mao, H.-Q.2
  • 24
    • 77957314287 scopus 로고    scopus 로고
    • The effect of nanofiber-guided cell alignment on the preferential differentiation of neural stem cells
    • Lim, S. H., Liu, X. Y., Song, H., Yarema, K. J. and Mao, H.-Q. (2010). The effect of nanofiber-guided cell alignment on the preferential differentiation of neural stem cells. Biomaterials 31, 9031-9039.
    • (2010) Biomaterials , vol.31 , pp. 9031-9039
    • Lim, S.H.1    Liu, X.Y.2    Song, H.3    Yarema, K.J.4    Mao, H.Q.5
  • 25
    • 40049105898 scopus 로고    scopus 로고
    • Electrospun nanofiber scaffolds for rapid and rich capture of bone marrowderived hematopoietic stem cells
    • Ma, K., Chan, C. K., Liao, S., Hwang, W. Y. K., Feng, Q. and Ramakrishna, S. (2008). Electrospun nanofiber scaffolds for rapid and rich capture of bone marrowderived hematopoietic stem cells. Biomaterials 29, 2096-2103.
    • (2008) Biomaterials , vol.29 , pp. 2096-2103
    • Ma, K.1    Chan, C.K.2    Liao, S.3    Hwang, W.Y.K.4    Feng, Q.5    Ramakrishna, S.6
  • 26
    • 80755153156 scopus 로고    scopus 로고
    • Rac1 GTPase-deficient mouse lens exhibits defects in shape, suture formation, fiber cell migration and survival
    • Maddala, R., Chauhan, B. K., Walker, C., Zheng, Y., Robinson, M. L., Lang, R. A. and Rao, P. V. (2011). Rac1 GTPase-deficient mouse lens exhibits defects in shape, suture formation, fiber cell migration and survival. Dev. Biol. 360, 30-43.
    • (2011) Dev. Biol. , vol.360 , pp. 30-43
    • Maddala, R.1    Chauhan, B.K.2    Walker, C.3    Zheng, Y.4    Robinson, M.L.5    Lang, R.A.6    Rao, P.V.7
  • 28
    • 77952682209 scopus 로고    scopus 로고
    • Noggin, retinoids, and fibroblast growth factor regulate hepatic or pancreatic fate of human embryonic stem cells
    • 2245.e1-14
    • Mfopou, J. K., Chen, B., Mateizel, I., Sermon, K. and Bouwens, L. (2010). Noggin, retinoids, and fibroblast growth factor regulate hepatic or pancreatic fate of human embryonic stem cells. Gastroenterology 138, 2233-2245, 2245.e1-14.
    • (2010) Gastroenterology , vol.138 , pp. 2233-2245
    • Mfopou, J.K.1    Chen, B.2    Mateizel, I.3    Sermon, K.4    Bouwens, L.5
  • 29
    • 39049114765 scopus 로고    scopus 로고
    • The inhibition of the expression of the small Rho GTPase Rac1 induces differentiation with no effect on cell proliferation in growing human adult keratinocytes
    • Nikolova, E., Mitev, V., Minner, F., Deroanne, C. F. and Poumay, Y. (2008). The inhibition of the expression of the small Rho GTPase Rac1 induces differentiation with no effect on cell proliferation in growing human adult keratinocytes. J. Cell. Biochem. 103, 857-864.
    • (2008) J. Cell. Biochem. , vol.103 , pp. 857-864
    • Nikolova, E.1    Mitev, V.2    Minner, F.3    Deroanne, C.F.4    Poumay, Y.5
  • 30
    • 0028961293 scopus 로고
    • Rho, rac, and cdc42 GTPases regulate the assembly of multimolecular focal complexes associated with actin stress fibers, lamellipodia, and filopodia
    • Nobes, C. D. and Hall, A. (1995). Rho, rac, and cdc42 GTPases regulate the assembly of multimolecular focal complexes associated with actin stress fibers, lamellipodia, and filopodia. Cell 81, 53-62.
    • (1995) Cell , vol.81 , pp. 53-62
    • Nobes, C.D.1    Hall, A.2
  • 32
    • 33746863742 scopus 로고    scopus 로고
    • Three-dimensional nanofibrillar surfaces promote self-renewal in mouse embryonic stem cells
    • Nur-E-Kamal, A., Ahmed, I., Kamal, J., Schindler, M. and Meiners, S. (2006). Three-dimensional nanofibrillar surfaces promote self-renewal in mouse embryonic stem cells. Stem Cells 24, 426-433.
    • (2006) Stem Cells , vol.24 , pp. 426-433
    • Nur-E-Kamal, A.1    Ahmed, I.2    Kamal, J.3    Schindler, M.4    Meiners, S.5
  • 33
    • 84869002559 scopus 로고    scopus 로고
    • Combining topographical and genetic cues to promote neuronal fate specification in stem cells
    • Purcell, E. K., Naim, Y., Yang, A., Leach, M. K., Velkey, J. M., Duncan, R. K. and Corey, J. M. (2012). Combining topographical and genetic cues to promote neuronal fate specification in stem cells. Biomacromolecules 13, 3427-3438.
    • (2012) Biomacromolecules , vol.13 , pp. 3427-3438
    • Purcell, E.K.1    Naim, Y.2    Yang, A.3    Leach, M.K.4    Velkey, J.M.5    Duncan, R.K.6    Corey, J.M.7
  • 34
    • 0026654125 scopus 로고
    • The small GTP-binding protein rac regulates growth factor-induced membrane ruffling
    • Ridley, J., Paterson, H. F., Johnston, C. L., Diekmann, D. and Hall, A. (1992). The small GTP-binding protein rac regulates growth factor-induced membrane ruffling. Cell 70, 401-410.
    • (1992) Cell , vol.70 , pp. 401-410
    • Ridley, J.1    Paterson, H.F.2    Johnston, C.L.3    Diekmann, D.4    Hall, A.5
  • 35
    • 0035423751 scopus 로고    scopus 로고
    • Distinct mesodermal signals, including BMPs from the septum transversum mesenchyme, are required in combination for hepatogenesis from the endoderm
    • Rossi, J. M., Dunn, N. R., Hogan, B. L. and Zaret, K. S. (2001). Distinct mesodermal signals, including BMPs from the septum transversum mesenchyme, are required in combination for hepatogenesis from the endoderm. Genes Dev. 15, 1998-2009.
    • (2001) Genes Dev. , vol.15 , pp. 1998-2009
    • Rossi, J.M.1    Dunn, N.R.2    Hogan, B.L.3    Zaret, K.S.4
  • 37
    • 18044380649 scopus 로고    scopus 로고
    • A synthetic nanofibrillar matrix promotes in vivo-like organization and morphogenesis for cells in culture
    • Schindler, M., Ahmed, I., Kamal, J., Nur-E-Kamal, A., Grafe, T. H., Young Chung, H. and Meiners, S. (2005). A synthetic nanofibrillar matrix promotes in vivo-like organization and morphogenesis for cells in culture. Biomaterials 26, 5624-5631.
    • (2005) Biomaterials , vol.26 , pp. 5624-5631
    • Schindler, M.1    Ahmed, I.2    Kamal, J.3    Nur-E-Kamal, A.4    Grafe, T.H.5    Young Chung, H.6    Meiners, S.7
  • 39
    • 33750552711 scopus 로고    scopus 로고
    • Growth of mesenchymal stem cells on electrospun type I collagen nanofibers
    • Shih, Y.-R. V., Chen, C.-N., Tsai, S.-W., Wang, Y. J. and Lee, O. K. (2006). Growth of mesenchymal stem cells on electrospun type I collagen nanofibers. Stem Cells 24, 2391-2397.
    • (2006) Stem Cells , vol.24 , pp. 2391-2397
    • Shih, Y.-R.V.1    Chen, C.-N.2    Tsai, S.-W.3    Wang, Y.J.4    Lee, O.K.5
  • 41
    • 48949112425 scopus 로고    scopus 로고
    • Guided differentiation of embryonic stem cells into Pdx1-expressing regional-specific definitive endoderm
    • Shiraki, N., Yoshida, T., Araki, K., Umezawa, A., Higuchi, Y., Goto, H., Kume, K. and Kume, S. (2008a). Guided differentiation of embryonic stem cells into Pdx1-expressing regional-specific definitive endoderm. Stem Cells 26, 874-885.
    • (2008) Stem Cells , vol.26 , pp. 874-885
    • Shiraki, N.1    Yoshida, T.2    Araki, K.3    Umezawa, A.4    Higuchi, Y.5    Goto, H.6    Kume, K.7    Kume, S.8
  • 42
    • 48949120846 scopus 로고    scopus 로고
    • Differentiation of mouse and human embryonic stem cells into hepatic lineages
    • Shiraki, N., Umeda, K., Sakashita, N., Takeya, M., Kume, K. and Kume, S. (2008b). Differentiation of mouse and human embryonic stem cells into hepatic lineages. Genes Cells 13, 731-746.
    • (2008) Genes Cells , vol.13 , pp. 731-746
    • Shiraki, N.1    Umeda, K.2    Sakashita, N.3    Takeya, M.4    Kume, K.5    Kume, S.6
  • 43
    • 80052060053 scopus 로고    scopus 로고
    • Efficient differentiation of embryonic stem cells into hepatic cells in vitro using a feeder-free basement membrane substratum
    • Shiraki, N., Yamazoe, T., Qin, Z., Ohgomori, K., Mochitate, K., Kume, K. and Kume, S. (2011). Efficient differentiation of embryonic stem cells into hepatic cells in vitro using a feeder-free basement membrane substratum. PLoS ONE 6, e24228.
    • (2011) PLoS ONE , vol.6
    • Shiraki, N.1    Yamazoe, T.2    Qin, Z.3    Ohgomori, K.4    Mochitate, K.5    Kume, K.6    Kume, S.7
  • 45
    • 0027437547 scopus 로고
    • Scatter factor/hepatocyte growth factor and its receptor, the c-met tyrosine kinase, can mediate a signal exchange between mesenchyme and epithelia during mouse development
    • Sonnenberg, E., Meyer, D., Weidner, K. M. and Birchmeier, C. (1993). Scatter factor/hepatocyte growth factor and its receptor, the c-met tyrosine kinase, can mediate a signal exchange between mesenchyme and epithelia during mouse development. J. Cell Biol. 123, 223-235.
    • (1993) J. Cell Biol. , vol.123 , pp. 223-235
    • Sonnenberg, E.1    Meyer, D.2    Weidner, K.M.3    Birchmeier, C.4
  • 46
    • 0033947662 scopus 로고    scopus 로고
    • Rac1 mutations produce aberrant epithelial differentiation in the developing and adult mouse small intestine
    • Stappenbeck, T. S. and Gordon, J. I. (2000). Rac1 mutations produce aberrant epithelial differentiation in the developing and adult mouse small intestine. Development 127, 2629-2642.
    • (2000) Development , vol.127 , pp. 2629-2642
    • Stappenbeck, T.S.1    Gordon, J.I.2
  • 47
    • 33646851050 scopus 로고    scopus 로고
    • Efficient establishment of human embryonic stem cell lines and long-term maintenance with stable karyotype by enzymatic bulk passage
    • Suemori, H., Yasuchika, K., Hasegawa, K., Fujioka, T., Tsuneyoshi, N. and Nakatsuji, N. (2006). Efficient establishment of human embryonic stem cell lines and long-term maintenance with stable karyotype by enzymatic bulk passage. Biochem. Biophys. Res. Commun. 345, 926-932.
    • (2006) Biochem. Biophys. Res. Commun. , vol.345 , pp. 926-932
    • Suemori, H.1    Yasuchika, K.2    Hasegawa, K.3    Fujioka, T.4    Tsuneyoshi, N.5    Nakatsuji, N.6
  • 49
    • 0033854950 scopus 로고    scopus 로고
    • Formation of the definitive endoderm in mouse is a Smad2-dependent process
    • Tremblay, K. D., Hoodless, P. A., Bikoff, E. K. and Robertson, E. J. (2000). Formation of the definitive endoderm in mouse is a Smad2-dependent process. Development 127, 3079-3090.
    • (2000) Development , vol.127 , pp. 3079-3090
    • Tremblay, K.D.1    Hoodless, P.A.2    Bikoff, E.K.3    Robertson, E.J.4
  • 50
    • 84871773008 scopus 로고    scopus 로고
    • Albumin gene targeting in human embryonic stem cells and induced pluripotent stem cells with helper-dependent adenoviral vector to monitor hepatic differentiation
    • Umeda, K., Suzuki, K., Yamazoe, T., Shiraki, N., Higuchi, Y., Tokieda, K., Kume, K., Mitani, K. and Kume, S. (2013). Albumin gene targeting in human embryonic stem cells and induced pluripotent stem cells with helper-dependent adenoviral vector to monitor hepatic differentiation. Stem Cell Res. 10, 179-194.
    • (2013) Stem Cell Res. , vol.10 , pp. 179-194
    • Umeda, K.1    Suzuki, K.2    Yamazoe, T.3    Shiraki, N.4    Higuchi, Y.5    Tokieda, K.6    Kume, K.7    Mitani, K.8    Kume, S.9
  • 51
    • 50949127989 scopus 로고    scopus 로고
    • TGFbeta1 regulates endothelial cell spreading and hypertrophy through a Rac-p38-mediated pathway
    • Varon, C., Rottiers, P., Ezan, J., Reuzeau, E., Basoni, C., Kramer, I. and Génot, E. (2008). TGFbeta1 regulates endothelial cell spreading and hypertrophy through a Rac-p38-mediated pathway. Biol. Cell 100, 537-550.
    • (2008) Biol. Cell , vol.100 , pp. 537-550
    • Varon, C.1    Rottiers, P.2    Ezan, J.3    Reuzeau, E.4    Basoni, C.5    Kramer, I.6    Génot, E.7
  • 52
    • 84866405842 scopus 로고    scopus 로고
    • Nodal signaling regulates endodermal cell motility and actin dynamics via Rac1 and Prex1
    • Woo, S., Housley, M. P., Weiner, O. D. and Stainier, D. Y. R. (2012). Nodal signaling regulates endodermal cell motility and actin dynamics via Rac1 and Prex1. J. Cell Biol. 198, 941-952.
    • (2012) J. Cell Biol. , vol.198 , pp. 941-952
    • Woo, S.1    Housley, M.P.2    Weiner, O.D.3    Stainier, D.Y.R.4
  • 53
    • 55249093369 scopus 로고    scopus 로고
    • The differentiation of embryonic stem cells seeded on electrospun nanofibers into neural lineages
    • Xie, J., Willerth, S. M., Li, X., Macewan, M. R., Rader, A., Sakiyama-Elbert, S. E. and Xia, Y. (2009). The differentiation of embryonic stem cells seeded on electrospun nanofibers into neural lineages. Biomaterials 30, 354-362.
    • (2009) Biomaterials , vol.30 , pp. 354-362
    • Xie, J.1    Willerth, S.M.2    Li, X.3    Macewan, M.R.4    Rader, A.5    Sakiyama-Elbert, S.E.6    Xia, Y.7


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