This study was performed to investigate the effects of transforming growth factor-β1 (TGF-β1) latency-associated peptide (LAP) and betaglycan on TGF-β1 activity, and on the glucose-induced overproduction of fibronectin in cultured human mesangial cells (MCs). We found that recombinant LAP and recombinant soluble betaglycan decrease the active form of TGF-β1, measured by ELISA, in a dose-dependent manner in a cell-free system. The effective dosages of LAP and soluble betaglycan for a 50% reduction were approximately 20- and 75-fold of the TGF-β1 concentration, respectively. The active form of TGF-β1 in the media secreted from MCs was significantly (p < 0.01) reduced by the addition of 10 nmol/l LAP and 10 nmol/l soluble betaglycan with no significant change in total (active + latent) TGF-β1. Recombinant LAP and soluble betaglycan also inhibited a recombinant TGF-β1-stimulated increase in fibronectin production in MCs. Furthermore, the glucose-induced increase in fibronectin secreted from MCs was significantly (p < 0.01) suppressed by concomitant incubation with LAP or soluble betaglycan, while these agents had no effect on fibronectin production under physiological glucose concentrations. These results indicate that recombinant LAP and soluble betaglycan suppress the glucose-induced overproduction of fibronectin presumably via inhibition of TGF-β1 activity in MCs. Further in vivo studies are needed to define the possible beneficial effects of these agents in diabetic nephropathy.

Keywords:
Transforming growth factor-β1, Latency-associated peptide, TGF-β1, Betaglycan, Mesangial cells
1.
Wolf G, Sharma K, Chen Y, Ericksen M, Ziyadeh FN: High glucose-induced proliferation in mesangial cells is reversed by autocrine TGF-β. Kidney Int 1992;42:647–656.
2.
Ziyadeh FN, Sharma K, Ericksen M, Wolf G: Stimulation of collagen gene expression and protein synthesis in murine mesangial cells by high glucose is mediated by autocrine activation of TGF-β. J Clin Invest 1994;93:536–542.
3.
Ishii H, Tada H, Isogai S: An aldose reductase inhibitor prevents glucose-induced increase in transforming growth factor-β and protein kinase C activity in cultured human mesangial cells. Diabetologia 1998;41:362–364.
4.
Iwano M, Kubo A, Nishino T, Sato H, Nishioka H, Akai Y, Kurioka H, Fujii Y, Kanauchi M, Shiiki H, Dohi K: Quantification of glomerular TGF-β1 mRNA in patients with diabetes mellitus. Kidney Int 1996;49:1120–1126.
5.
Sharma K, Jin Y, Guo J, Ziyadeh N: Neutralization of TGF-β by anti-TGF-β antibody attenuates kidney hypertrophy and the enhanced extracellular matrix gene expression in STZ-induced diabetic mice. Diabetes 1996;45:522–530.
6.
Yang CW, Hattori M, Vlassara H, He CJ, Carome MA, Yamato E, Elliot S, Striker GE, Striker LJ: Overexpression of transforming growth factor-β1 mRNA is associated with up-regulation of glomerular tenascin and laminin gene expression in nonobese diabetic mice. J Am Soc Nephrol 1995;5:1610–1617.
7.
Shankland SJ, Scholey JW, Ly H: Expression of transforming growth factor-β1 during diabetic renal hypertrophy. Kidney Int 1994;46:430–442.
8.
Munger JS, Harpel JG, Gleizes PE, Mazzieri R, Irene N, Rifkin DB: Latent transforming growth factor-β: Structural featured and mechanisms of activation. Kidney Int 1997;51:1376–1382.
9.
Craven PA, Studer RK, Felder J, Phillips S, DeRubertis FR: Nitric oxide inhibition of transforming growth factor-β and collagen synthesis in mesangial cells. Diabetes 1997;46:671–681.
10.
Gilbert RE, Wilkinson-Berka JL, Johnson DW, Cox A, Soulis T, Wu LL, Kelly DJ, Jerums G, Pollock CA, Cooper ME: Renal expression of transforming growth factor-inducible gene-h3 (βig-h3) in normal and diabetic rats. Kidney Int 1998;54:1052–1062.
11.
Böttinger EP, Factor VM, Tsang MLS, Weatherbee JA, Kopp JB, Qian SW, Wakefield LM, Roberts AB, Thorgeirsson SS, Sporn MB: The recombinant proregion of transforming growth factor-β1 (latency-associated peptide) inhibits active transforming growth factor-β1 in transgenic mice. Proc Natl Acad Sci USA 1996;93:5877–5882.
12.
Lopez-Casillas F, Payne HM, Andres JL, Massague J: Betaglycan can act as a dual modulator of TGF-β access to signaling receptors: Mapping of ligand binding and GAG attachment sites. J Cell Biol 1994;124:557–568.
13.
Tada H, Ishii H, Isogai S: Protective effect of D-alpha-tocopherol on the function of human mesangial cells exposed to high glucose concentrations. Metabolism 1997;46:779–784.
14.
Striker GE, Striker LJ: Biology of disease – Glomerular cell culture. Lab Invest 1985;53:122–131.
15.
Danielpour D, Kim KY, Dart LL, Watanabe S, Roberts AB, Sporn MB: Sandwich enzyme linked immunosorbent assays (SELISAs) quantitate and distinguish two forms of transforming growth factor-beta (TGF-β1 and TGF-β2) in complex biological fluids. Growth Factors 1989;2:61–71.
16.
Cesarone CF, Bolognesi C, Santi L: Improved microfluorometric DNA determination in biological material using 33258 Hoechst. Anal Biochem 1979;100:188–197.
17.
Glanz SA: Primer of Biostatistics. New York, McGraw Hill, 1981.
18.
Singh R, Alavi N, Singh AK, Leehey DJ: Role of angiotensin II in glucose-induced inhibition of mesangial matrix degradation. Diabetes 1999;48:2066–2073.
19.
Negrete H, Studer RK, Craven PA, DeRubertis FR: Role for transforming growth factor β in thromboxane-induced increases in mesangial cell fibronectin synthesis. Diabetes 1995;44:335–339.
20.
Throckmorton DC, Brogden AP, Min B, Rasmussen H, Kashgarian M: PDGF and TGF-β mediate collagen production by mesangial cells exposed to advanced glycosylation end products. Kidney Int 1995;48:111–117.
21.
Tada H, Isogai S: The fibronectin production is increased by thrombospondin via activation of TGF-β in cultured human mesangial cells. Nephron 1998;79:38–43.
22.
Kagami S, Border WA, Miller DE, Noble NA: Angiotensin II stimulates extracellular matrix protein synthesis through induction of transforming growth factor-β expression in rat glomerular mesangial cells. J Clin Invest 1994;93:2431–2437.
23.
Koya D, Jirousek MR, Lin JY, Ishii H, Kuboki K, King G: Characterization of protein kinase C β isoform activation on the gene expression of transforming growth factor-β, extracellular matrix components, and prostanoids in the glomeruli of diabetic rats. J Clin Invest 1997;100:115–126.
24.
Ziyadeh FN, Hoffman BB, Han DC, Cruz MC, Hong SW, Isono M, Chen S, McGowan TA, Sharma K: Long-term prevention of renal insufficiency, excess matrix gene expression, and glomerular mesangial matrix expansion by treatment with monoclonal antitransforming growth factor-b antibody in db/db diabetic mice. Proc Natl Acad Sci USA 2000;97:8015–8020.
25.
Andres JL, Stanley K, Cheifetz S, Massague J: Membrane-anchored and soluble forms of betaglycan, a polymorphic proteoglycan that binds transforming growth factor-β. J Cell Biol 1989;109:3137–3145.
© 2002 S. Karger AG, Basel
2002
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.