Abstract
Connective tissue growth factor (CTGF) is a secreted cysteine-rich protein now considered as an important effector molecule in both physiological and pathological processes. An increasing amount of evidence indicates that CTGF plays a key role in the pathogenesis of different fibrotic disorders including diabetic nephropathy. However, the molecular mechanisms by which CTGF exerts its effects are not known. Here we provide the first evidence for the existence of an intracellular transport pathway for the growth factor in human mesangial cells. Our results demonstrate that CTGF is internalized from the cell surface in endosomes and accumulates in a juxtanuclear organelle from which the growth factor is then translocated into the cytosol. In the cytosol CTGF is phosphorylated by protein kinase C and PMA treatment can enhance this phosphorylation. Phosphorylated CTGF may have an important role in the cytosol, but it is also translocated into the nucleus where it may directly affect transcription.
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- Allen J. T., Knight R. A., Bloor C. A., Spiteri M. A. Enhanced insulin-like growth factor binding protein-related protein 2 (Connective tissue growth factor) expression in patients with idiopathic pulmonary fibrosis and pulmonary sarcoidosis. Am J Respir Cell Mol Biol. 1999 Dec;21(6):693–700. doi: 10.1165/ajrcmb.21.6.3719. [DOI] [PubMed] [Google Scholar]
- Babic A. M., Chen C. C., Lau L. F. Fisp12/mouse connective tissue growth factor mediates endothelial cell adhesion and migration through integrin alphavbeta3, promotes endothelial cell survival, and induces angiogenesis in vivo. Mol Cell Biol. 1999 Apr;19(4):2958–2966. doi: 10.1128/mcb.19.4.2958. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Boes M., Dake B. L., Booth B. A., Erondu N. E., Oh Y., Hwa V., Rosenfeld R., Bar R. S. Connective tissue growth factor (IGFBP-rP2) expression and regulation in cultured bovine endothelial cells. Endocrinology. 1999 Apr;140(4):1575–1580. doi: 10.1210/endo.140.4.6633. [DOI] [PubMed] [Google Scholar]
- Bork P. The modular architecture of a new family of growth regulators related to connective tissue growth factor. FEBS Lett. 1993 Jul 26;327(2):125–130. doi: 10.1016/0014-5793(93)80155-n. [DOI] [PubMed] [Google Scholar]
- Bottger B. A., Sjölund M., Thyberg J. Chloroquine and monensin inhibit induction of DNA synthesis in rat arterial smooth muscle cells stimulated with platelet-derived growth factor. Cell Tissue Res. 1988 May;252(2):275–285. doi: 10.1007/BF00214369. [DOI] [PubMed] [Google Scholar]
- Bradham D. M., Igarashi A., Potter R. L., Grotendorst G. R. Connective tissue growth factor: a cysteine-rich mitogen secreted by human vascular endothelial cells is related to the SRC-induced immediate early gene product CEF-10. J Cell Biol. 1991 Sep;114(6):1285–1294. doi: 10.1083/jcb.114.6.1285. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brigstock D. R., Steffen C. L., Kim G. Y., Vegunta R. K., Diehl J. R., Harding P. A. Purification and characterization of novel heparin-binding growth factors in uterine secretory fluids. Identification as heparin-regulated Mr 10,000 forms of connective tissue growth factor. J Biol Chem. 1997 Aug 8;272(32):20275–20282. doi: 10.1074/jbc.272.32.20275. [DOI] [PubMed] [Google Scholar]
- Chen M. M., Lam A., Abraham J. A., Schreiner G. F., Joly A. H. CTGF expression is induced by TGF- beta in cardiac fibroblasts and cardiac myocytes: a potential role in heart fibrosis. J Mol Cell Cardiol. 2000 Oct;32(10):1805–1819. doi: 10.1006/jmcc.2000.1215. [DOI] [PubMed] [Google Scholar]
- Dammeier J., Beer H. D., Brauchle M., Werner S. Dexamethasone is a novel potent inducer of connective tissue growth factor expression. Implications for glucocorticoid therapy. J Biol Chem. 1998 Jul 17;273(29):18185–18190. doi: 10.1074/jbc.273.29.18185. [DOI] [PubMed] [Google Scholar]
- Frazier K. S., Grotendorst G. R. Expression of connective tissue growth factor mRNA in the fibrous stroma of mammary tumors. Int J Biochem Cell Biol. 1997 Jan;29(1):153–161. doi: 10.1016/s1357-2725(96)00127-6. [DOI] [PubMed] [Google Scholar]
- Grieb T. A., Burgess W. H. The mitogenic activity of fibroblast growth factor-1 correlates with its internalization and limited proteolytic processing. J Cell Physiol. 2000 Aug;184(2):171–182. doi: 10.1002/1097-4652(200008)184:2<171::AID-JCP4>3.0.CO;2-J. [DOI] [PubMed] [Google Scholar]
- Grishin N. V. The R3H motif: a domain that binds single-stranded nucleic acids. Trends Biochem Sci. 1998 Sep;23(9):329–330. doi: 10.1016/s0968-0004(98)01258-4. [DOI] [PubMed] [Google Scholar]
- Gruenberg J., Maxfield F. R. Membrane transport in the endocytic pathway. Curr Opin Cell Biol. 1995 Aug;7(4):552–563. doi: 10.1016/0955-0674(95)80013-1. [DOI] [PubMed] [Google Scholar]
- Haberberger T. C., Kupfer K., Murphy J. E. Profiling of genes which are differentially expressed in mouse liver in response to adenoviral vectors and delivered genes. Gene Ther. 2000 Jun;7(11):903–909. doi: 10.1038/sj.gt.3301181. [DOI] [PubMed] [Google Scholar]
- Hopkins C. R., Gibson A., Shipman M., Strickland D. K., Trowbridge I. S. In migrating fibroblasts, recycling receptors are concentrated in narrow tubules in the pericentriolar area, and then routed to the plasma membrane of the leading lamella. J Cell Biol. 1994 Jun;125(6):1265–1274. doi: 10.1083/jcb.125.6.1265. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hug H., Sarre T. F. Protein kinase C isoenzymes: divergence in signal transduction? Biochem J. 1993 Apr 15;291(Pt 2):329–343. doi: 10.1042/bj2910329. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Igarashi A., Nashiro K., Kikuchi K., Sato S., Ihn H., Grotendorst G. R., Takehara K. Significant correlation between connective tissue growth factor gene expression and skin sclerosis in tissue sections from patients with systemic sclerosis. J Invest Dermatol. 1995 Aug;105(2):280–284. doi: 10.1111/1523-1747.ep12318465. [DOI] [PubMed] [Google Scholar]
- Imamura T., Engleka K., Zhan X., Tokita Y., Forough R., Roeder D., Jackson A., Maier J. A., Hla T., Maciag T. Recovery of mitogenic activity of a growth factor mutant with a nuclear translocation sequence. Science. 1990 Sep 28;249(4976):1567–1570. doi: 10.1126/science.1699274. [DOI] [PubMed] [Google Scholar]
- Ito Y., Aten J., Bende R. J., Oemar B. S., Rabelink T. J., Weening J. J., Goldschmeding R. Expression of connective tissue growth factor in human renal fibrosis. Kidney Int. 1998 Apr;53(4):853–861. doi: 10.1111/j.1523-1755.1998.00820.x. [DOI] [PubMed] [Google Scholar]
- Jedsadayanmata A., Chen C. C., Kireeva M. L., Lau L. F., Lam S. C. Activation-dependent adhesion of human platelets to Cyr61 and Fisp12/mouse connective tissue growth factor is mediated through integrin alpha(IIb)beta(3). J Biol Chem. 1999 Aug 20;274(34):24321–24327. doi: 10.1074/jbc.274.34.24321. [DOI] [PubMed] [Google Scholar]
- Kim H. S., Nagalla S. R., Oh Y., Wilson E., Roberts C. T., Jr, Rosenfeld R. G. Identification of a family of low-affinity insulin-like growth factor binding proteins (IGFBPs): characterization of connective tissue growth factor as a member of the IGFBP superfamily. Proc Natl Acad Sci U S A. 1997 Nov 25;94(24):12981–12986. doi: 10.1073/pnas.94.24.12981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kimura H. Schwannoma-derived growth factor must be transported into the nucleus to exert its mitogenic activity. Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2165–2169. doi: 10.1073/pnas.90.6.2165. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kireeva M. L., Lam S. C., Lau L. F. Adhesion of human umbilical vein endothelial cells to the immediate-early gene product Cyr61 is mediated through integrin alphavbeta3. J Biol Chem. 1998 Jan 30;273(5):3090–3096. doi: 10.1074/jbc.273.5.3090. [DOI] [PubMed] [Google Scholar]
- Klingenberg O., Widlocha A., Rapak A., Muñoz R., Falnes P., Olsnes S. Inability of the acidic fibroblast growth factor mutant K132E to stimulate DNA synthesis after translocation into cells. J Biol Chem. 1998 May 1;273(18):11164–11172. doi: 10.1074/jbc.273.18.11164. [DOI] [PubMed] [Google Scholar]
- Klingenberg O., Wiedlocha A., Olsnes S. Effects of mutations of a phosphorylation site in an exposed loop in acidic fibroblast growth factor. J Biol Chem. 1999 Jun 18;274(25):18081–18086. doi: 10.1074/jbc.274.25.18081. [DOI] [PubMed] [Google Scholar]
- Klingenberg O., Wiedocha A., Citores L., Olsnes S. Requirement of phosphatidylinositol 3-kinase activity for translocation of exogenous aFGF to the cytosol and nucleus. J Biol Chem. 2000 Apr 21;275(16):11972–11980. doi: 10.1074/jbc.275.16.11972. [DOI] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Mason I. J. The ins and outs of fibroblast growth factors. Cell. 1994 Aug 26;78(4):547–552. doi: 10.1016/0092-8674(94)90520-7. [DOI] [PubMed] [Google Scholar]
- Mellor H., Parker P. J. The extended protein kinase C superfamily. Biochem J. 1998 Jun 1;332(Pt 2):281–292. doi: 10.1042/bj3320281. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moll T., Tebb G., Surana U., Robitsch H., Nasmyth K. The role of phosphorylation and the CDC28 protein kinase in cell cycle-regulated nuclear import of the S. cerevisiae transcription factor SWI5. Cell. 1991 Aug 23;66(4):743–758. doi: 10.1016/0092-8674(91)90118-i. [DOI] [PubMed] [Google Scholar]
- Moroianu J., Riordan J. F. Nuclear translocation of angiogenin in proliferating endothelial cells is essential to its angiogenic activity. Proc Natl Acad Sci U S A. 1994 Mar 1;91(5):1677–1681. doi: 10.1073/pnas.91.5.1677. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Muñoz R., Klingenberg O., Wiedłocha A., Rapak A., Falnes P. O., Olsnes S. Effect of mutation of cytoplasmic receptor domain and of genistein on transport of acidic fibroblast growth factor into cells. Oncogene. 1997 Jul 31;15(5):525–536. doi: 10.1038/sj.onc.1201226. [DOI] [PubMed] [Google Scholar]
- Nigg E. A. Nucleocytoplasmic transport: signals, mechanisms and regulation. Nature. 1997 Apr 24;386(6627):779–787. doi: 10.1038/386779a0. [DOI] [PubMed] [Google Scholar]
- Nishida T., Nakanishi T., Shimo T., Asano M., Hattori T., Tamatani T., Tezuka K., Takigawa M. Demonstration of receptors specific for connective tissue growth factor on a human chondrocytic cell line (HCS-2/8). Biochem Biophys Res Commun. 1998 Jun 29;247(3):905–909. doi: 10.1006/bbrc.1998.8895. [DOI] [PubMed] [Google Scholar]
- Paradis V., Dargere D., Vidaud M., De Gouville A. C., Huet S., Martinez V., Gauthier J. M., Ba N., Sobesky R., Ratziu V. Expression of connective tissue growth factor in experimental rat and human liver fibrosis. Hepatology. 1999 Oct;30(4):968–976. doi: 10.1002/hep.510300425. [DOI] [PubMed] [Google Scholar]
- Perbal B. Nuclear localisation of NOVH protein: a potential role for NOV in the regulation of gene expression. Mol Pathol. 1999 Apr;52(2):84–91. doi: 10.1136/mp.52.2.84. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schäffer A. A., Wolf Y. I., Ponting C. P., Koonin E. V., Aravind L., Altschul S. F. IMPALA: matching a protein sequence against a collection of PSI-BLAST-constructed position-specific score matrices. Bioinformatics. 1999 Dec;15(12):1000–1011. doi: 10.1093/bioinformatics/15.12.1000. [DOI] [PubMed] [Google Scholar]
- Shi-wen X., Pennington D., Holmes A., Leask A., Bradham D., Beauchamp J. R., Fonseca C., du Bois R. M., Martin G. R., Black C. M. Autocrine overexpression of CTGF maintains fibrosis: RDA analysis of fibrosis genes in systemic sclerosis. Exp Cell Res. 2000 Aug 25;259(1):213–224. doi: 10.1006/excr.2000.4972. [DOI] [PubMed] [Google Scholar]
- Shimo T., Nakanishi T., Nishida T., Asano M., Kanyama M., Kuboki T., Tamatani T., Tezuka K., Takemura M., Matsumura T. Connective tissue growth factor induces the proliferation, migration, and tube formation of vascular endothelial cells in vitro, and angiogenesis in vivo. J Biochem. 1999 Jul;126(1):137–145. doi: 10.1093/oxfordjournals.jbchem.a022414. [DOI] [PubMed] [Google Scholar]
- Smith R. M., Harada S., Jarett L. Insulin internalization and other signaling pathways in the pleiotropic effects of insulin. Int Rev Cytol. 1997;173:243–280. doi: 10.1016/s0074-7696(08)62479-1. [DOI] [PubMed] [Google Scholar]
- Solari R., Smithers N., Kennard N., Ray K., Grenfell S. Receptor mediated endocytosis and intracellular fate of interleukin 1. Biochem Pharmacol. 1994 Jan 13;47(1):93–101. doi: 10.1016/0006-2952(94)90441-3. [DOI] [PubMed] [Google Scholar]
- Stachowiak M. K., Moffett J., Joy A., Puchacz E., Florkiewicz R., Stachowiak E. K. Regulation of bFGF gene expression and subcellular distribution of bFGF protein in adrenal medullary cells. J Cell Biol. 1994 Oct;127(1):203–223. doi: 10.1083/jcb.127.1.203. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steffen C. L., Ball-Mirth D. K., Harding P. A., Bhattacharyya N., Pillai S., Brigstock D. R. Characterization of cell-associated and soluble forms of connective tissue growth factor (CTGF) produced by fibroblast cells in vitro. Growth Factors. 1998;15(3):199–213. doi: 10.3109/08977199809002117. [DOI] [PubMed] [Google Scholar]
- Surveyor G. A., Wilson A. K., Brigstock D. R. Localization of connective tissue growth factor during the period of embryo implantation in the mouse. Biol Reprod. 1998 Nov;59(5):1207–1213. doi: 10.1095/biolreprod59.5.1207. [DOI] [PubMed] [Google Scholar]
- Tagawa T., Kuroki T., Vogt P. K., Chida K. The cell cycle-dependent nuclear import of v-Jun is regulated by phosphorylation of a serine adjacent to the nuclear localization signal. J Cell Biol. 1995 Jul;130(2):255–263. doi: 10.1083/jcb.130.2.255. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wahab N. A., Harper K., Mason R. M. Expression of extracellular matrix molecules in human mesangial cells in response to prolonged hyperglycaemia. Biochem J. 1996 Jun 15;316(Pt 3):985–992. doi: 10.1042/bj3160985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wahab N. A., Yevdokimova N., Weston B. S., Roberts T., Li X. J., Brinkman H., Mason R. M. Role of connective tissue growth factor in the pathogenesis of diabetic nephropathy. Biochem J. 2001 Oct 1;359(Pt 1):77–87. doi: 10.1042/0264-6021:3590077. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wiedłocha A., Falnes P. O., Madshus I. H., Sandvig K., Olsnes S. Dual mode of signal transduction by externally added acidic fibroblast growth factor. Cell. 1994 Mar 25;76(6):1039–1051. doi: 10.1016/0092-8674(94)90381-6. [DOI] [PubMed] [Google Scholar]
- Wiedłocha A., Falnes P. O., Rapak A., Muñoz R., Klingenberg O., Olsnes S. Stimulation of proliferation of a human osteosarcoma cell line by exogenous acidic fibroblast growth factor requires both activation of receptor tyrosine kinase and growth factor internalization. Mol Cell Biol. 1996 Jan;16(1):270–280. doi: 10.1128/mcb.16.1.270. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yang D. H., Kim H. S., Wilson E. M., Rosenfeld R. G., Oh Y. Identification of glycosylated 38-kDa connective tissue growth factor (IGFBP-related protein 2) and proteolytic fragments in human biological fluids, and up-regulation of IGFBP-rP2 expression by TGF-beta in Hs578T human breast cancer cells. J Clin Endocrinol Metab. 1998 Jul;83(7):2593–2596. doi: 10.1210/jcem.83.7.5097. [DOI] [PubMed] [Google Scholar]
- Yang G. P., Lau L. F. Cyr61, product of a growth factor-inducible immediate early gene, is associated with the extracellular matrix and the cell surface. Cell Growth Differ. 1991 Jul;2(7):351–357. [PubMed] [Google Scholar]
- Zhan X., Hu X., Friesel R., Maciag T. Long term growth factor exposure and differential tyrosine phosphorylation are required for DNA synthesis in BALB/c 3T3 cells. J Biol Chem. 1993 May 5;268(13):9611–9620. [PubMed] [Google Scholar]