Keratinocytes have the ability to take up oligonucleotides (ODN) and plasmid DNA probably by receptor-mediated endocytosis or macropinocytosis. Despite the use of DNA for antisense and gene therapy, little is known about the regulation of genes following exposure to nucleic acids. To systematically identify gene regulation in keratinocytes upon exposure to ODN, we screened human cytokine DNA arrays containing 383 different genes and found interleukin-1α (IL-1α), IL-1β, integrin β1, α-tubulin and follistatin greatly induced, while most genes were unaffected. The time course and concentration dependence for IL-1α and follistatin was confirmed by the standard Northern blot technique and found to be induced by picomolar or femtomolar concentrations of ODN. ODN of different length and sequence induced comparable amounts of IL-1α and follistatin. Their induction was independent of the negative charge and of several proinflammatory compounds and proteins such as lipopolysaccharides, IL-1β or IFN-γ, but was partly inhibited by activin A. In summary, our study revealed several genes of the acute phase protein family that were induced in a non-sequence-specific manner following the exposure of normal human keratinocytes to ODN. Therefore, it is tempting to speculate that, upon internalization, ODN bind to an intracellular receptor (e.g. Toll-like receptor 9), which mediates signaling.

1.
Aderem, A., D.A. Hume (2000) How do you see CG? Cell 103: 993–996.
2.
Bauer, S., C.J. Kirschning, H. Hacker, V. Redecke S, Hausmann, S. Akira, H. Wagner, G.B. Lipford (2001) Human TLR9 confers responsiveness to bacterial DNA via species-specific CpG motif recognition. Proc Natl Acad Sci USA 98: 9237–9242.
3.
Beltinger, C., H.U. Saragovi, R.M. Smith, L. LeSauteur, N. Shah, L. DeDionisio, L. Christen sen, A. Raible, L. Jarett, A.M. Gewirtz (1995) Binding, uptake, and intracellular trafficking of phosphorothiate-modified oligodeoxynucleotides. J Clin Invest 95: 1814–1823.
4.
Benimetskaya, L., J.D. Loike, Z. Khaled, G. Loike, S.C. Silverstein, L. Cao, J.E. Khoury, T.Q. Cai, C.A. Stein (1997) Mac-1 (CD11/CD18) is an oligodeoxynucleotide-binding protein. Nat Med 3: 414–420.
5.
Brittigan, B.E., T.S. Lewis, M. Waldschmidt, M.L. McCormick, A.M. Krieg (2001) Lactoferrin binds CpG-containing oligonucleotides and inhibits their immunostimulatory effects on human B cells. J Immunol 167: 2921–2928.
6.
Budker, V., T. Budker, G. Zhang, V. Subbotin, A. Loomis, J.A. Wolff (2000) Hypothesis: Naked plasmid DNA is taken up by cells in vivo by a receptor-mediated process. J Gene Med 2: 76–88.
7.
Chu, R.S., O.S. Targoni, A.M. Krieg, P.V. Lehmann, C.V. Harding (1997) CpG oligodeoxynucleotides act as adjuvants that switch on T helper 1 (Th1) immunity. J Exp Med 186: 1623–1631.
8.
Hacker, H., H. Mischak, T. Miethke, S. Liptay, R. Schmid, T. Sparwasser, K. Heeg, G.B. Lipford, H. Wagner (1998) CpG-DNA-specific activation of antigen-presenting cells requires stress kinase activity and is preceded by non-specific endocytosis and endosomal maturation. EMBO J 17: 6230–6240.
9.
Hacker, H., R.M. Vabulas, O. Takeuchi, K. Hoshino, S. Akira, H. Wagner (2000) Immune cell activation by bacterial CpG-DNA through myeloid differentiation marker 88 and tumor necrosis factor receptor-associated factor (TRAF)6. J Exp Med 192: 595–600.
10.
Hanss, B., E. Leal-Pinto, L.A. Bruggeman, T.D. Copeland, P.E. Klotman (1998) Identification and characterization of a cell membrane nucleic acid channel. Proc Natl Acad Sci USA 95: 1921–1926.
11.
Hartmann, G., R.D. Weeratna, Z.K. Ballas, P. Payette, S. Blackwell, I. Suparto, W.L. Rasmussen, M. Waldschmidt, D. Sajuthi, R.H. Purcell, H.L. Davis, A.M. Krieg (2000) Delineation of a CpG phosphorotioate oligodeoxynucleotide for activating primate immune responses in vitro and in vivo. J Immunol 164:1617–1624.
12.
Hashimoto, O., T. Nakamura, H. Shoji, S. Shimasaki, Y. Hayashi, H. Sugino (1997) A novel role of follistatin, an activin-binding protein, in the inhibition of activin action in rat pituitary cells. Endocytotic degradation of activin and its acceleration by follistatin associated with cell-surface heparan sulfate. J Biol Chem 272:13835–13842.
13.
Hemmati-Brivanlou, A., O.G. Kelly, D.A. Melton (1994) Follistatin, an antagonist of activin, is expressed in the Speman organizer and displays direct neuralizing activity. Cell 77: 283–295.
14.
Hengge, U.R., E.F. Chan, V. Hampshire, R.A. Foster, J.C. Vogel (1996) The derivation and characterization of pig keratinocyte cell lines that retain the ability to differentiate. J Invest Dermatol 106: 287–293.
15.
Hubner, G., Q. Hu, H. Smola, S. Werner (1996) Strong induction of activin expression after injury suggests an important role of activin in wound repair. Dev Biol 1973: 490–498.
16.
Jones, K.L., J.N. Brauman, N.P. Groome, D.M. de Kretser, D.J. Phillips (2000) Activin A release into the circulation is an early event in systemic inflammation and precedes the release of follistatin. Endocrinology 141: 1905–1908.
17.
Klein, R., I.J. Clarke, M.P. Hedger, D.M. Robertson (1996) Plasma follistatin concentrations increase following lipopolysaccharide administration in sheep. Clin Exp Pharmacol Physiol 23: 754–755.
18.
Krieg, A.M. (2001) Now I know my CpGs. Trends Microbiol 9: 249–252.
19.
Krieg, A.M., A.K. Yi, S. Matson, T.J. Waldschmidt, G.A. Bishop, R. Teasdale, G. Koretzky, D. Klinman (1995) CpG motifs in bacterial DNA trigger direct B-cell activation. Nature 374: 546–549.
20.
Laktionov, P.P., J.E. Dazard, E. Vives, E.Y. Rykova, J. Piette, V.V. Vlassov, B. Lebleu (1999) Characterisation of membrane olignucleotide-binding proteins and oligonucleotide uptake in keratinocytes. Nucleic Acids Res 27: 2315–2324.
21.
Loisel, S., C. Le Gall, L. Doucet, C. Ferec, V. Floch (2001) Contribution of plasmid DNA to hepatotoxicity after systemic administration of lipoplexes. Hum Gene Ther 12: 685–696.
22.
Loke, S.L., C.A. Stein, X.H. Zhang, K. Mori, M. Nakanishi, C. Subasinghe, J.S. Cohen, L.M. Neckers (1989) Characterization of oligonucleotide transport into living cells. Proc Natl Acad Sci USA 86: 3474–3478.
23.
Macfarlane, D.E., L. Manzel (1998) Antagonism of immunostimulatory CpG-oligodeoxynucleotides by quinacrine, chloroquine, and structurally related compounds. J Immunol 160: 1122–1131.
24.
Maeshima, A., Y. Nojima, I. Kojima (2001) The role of the activin-follistatin system in the developmental and regeneration processes of the kidney. Cytokine Growth Factor Rev 12: 289–298.
25.
Mather, J.P., P.E. Roberts, L.A. Krummen (1993) Follistatin modulates activin activity in a cell- and tissue-specific manner. Endocrinology 132: 2732–2734.
26.
Matzuk, M.M., N. Lu, H. Vogel, K. Sellheyer, D.R. Roop, A. Bradley (1995) Multiple defects and perinatal death in mice deficient in follistatin. Nature 374: 360–363.
27.
Michel, U., O. Schneider, C. Kirchhof, S. Meisel, A. Smirnov, J. Wiltfang, P. Rieckmann (1996) Production of follistatin in porcine endothelial cells: Differential regulation by bacterial compounds and the synthetic glucocorticoid RU 28362. Endocrinology 137: 4925–4934.
28.
Nakamura, T., K. Takio, Y. Eto, H. Shibai, K. Titani, H. Sugino (1990) Activin-binding protein from rat ovary is follistatin. Science 247: 836–838.
29.
Noonberg, S.B., M.R. Garovoy, C.A. Hunt (1993) Characteristics of oligonucleotide uptake in human keratinocyte cultures. J Invest Dermatol 101: 727–731.
30.
Patel, K. (1998) Follistatin. Int J Biochem Cell Biol 30: 1087–1093.
31.
Phillips, D.J., M.P. Hedger, J.R. McFarlane, R. Klein, I.J. Clarke, A.J. Tilbrook, A.D. Nash, D.M. de Kretser (1996) Follistatin concentrations in male sheep increase following sham castration/castration or injection of interleukin-1 beta. J Endocrinol 151: 119–124.
32.
Phillips, D.J., K.L. Jones, J.Y. Scheerlinck, M.P. Hedger, D.M. de Kretser (2001) Evidence for activin A and follistatin involvement in the systemic inflammatory response. Mol Cell Endocrinol 180: 155–162.
33.
Robertson, D.M., R. Klein, F.L. de Vos, R.I. McLachlan, R.E. Wettenhall, M.T. Hearn, H.G. Burger, D.M. de Kretser (1987) The isolation of polypeptides with FSH suppressing activity from bovine follicular fluid which are structurally different to inhibin. Biochem Biophys Res Commun 149: 744–749.
34.
Seishima, M., M. Nojiri, T. Akiyama, M. Seishima, A. Noma, Y. Etoh, Y. Kitajima (1996) Expression of activin A in human keratinocytes at early stages of cultivation. FEBS Lett 398: 120–124.
35.
Shimasaki, S., M. Koga, F. Esch, K. Cooksey, M. Mercado, A. Koba, N. Ueno, S.Y. Ying, N. Ling, R. Guillemin (1988) Primary structure of the human follistatin precursor and its genomic organization. Proc Natl Acad Sci USA 85: 4218–4222.
36.
Wada, M., Y. Shintani, M. Kosaka, T. Sano, K. Hizawa, S. Saito (1996) Immunohistochemical localization of activin A and follistatin in human tissues. Endocr J 43: 375–385.
37.
Wankell, M., B. Munz, G. Hubner, W. Hans, E. Wolf, A. Goppelt, S. Werner (2001) Impaired wound healing in transgenic mice overexpressing the activin antagonist follistatin in the epidermis. EMBO J 20: 5361–5372.
38.
White, P.J., R.D. Fogarty, S.C. McKean, D.J. Venables, G.A. Werther, C.J. Wraight (1999) Oligonucleotide uptake in cultured keratinocytes: Influence of confluence, cationic liposomes, and keratinocyte cell type. J Invest Dermatol 112: 699–705.
39.
Wingens, M., C.A. Van Hooijdonk, G.J. de Jongh, J. Schalkwijk, P.E. van Erp (1998) Flow cytometric and microscopic characterization of the uptake and distribution of phosphorothioate oligonucleotides in human keratinocytes. Arch Dermatol Res 290: 119–125.
40.
Yakubov, L.A., E.A. Deeva, V.F. Zarytova, E.M. Ivanova, A.S. Ryte, L.V. Yurchenko, V.V. Vlassov (1989) Mechanism of oligonucleotide uptake by cells: Involvement of specific receptors? Proc Natl Acad Sci USA 86: 6454–6458.
41.
Yi, A.K., M. Chang, D.W. Peckham, A.M. Krieg, R.F. Ashman (1998) CpG oligodeoxyribonucleotides rescue mature spleen B cells from spontaneous apoptosis and promote cell cycle entry. J Immunol 160: 5898–5906.
42.
Yi, A.K. , D.M. Klinman, T.L. Martin, S. Matson, A.M. Krieg (1996) Rapid immune activation by CpG motifs in bacterial DNA: Systemic induction of IL-6 transcription through an antioxidant-sensitive pathway. J Immunol 157: 5394–5402.
43.
Yi, A.K., A.M. Krieg (1998) Rapid induction of mitogen activated protein kinases by immune stimulatory CpG DNA. J Immunol 161: 4493–4497.
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