Journal Article

Thrombin stimulates production of fibronectin by human proximal tubular epithelial cells via a transforming growth factor-β-dependent mechanism

Kenichi Shirato, Hiroshi Osawa, Mitsuaki Kaizuka, Norio Nakamura, Toshiyuki Sugawara, Masayuki Nakamura, Michiko Tamura, Hideaki Yamabe and Ken Okumura

in Nephrology Dialysis Transplantation

Published on behalf of European Renal Association - European Dialysis and Transplant Assoc

Volume 18, issue 11, pages 2248-2254
Published in print November 2003 | ISSN: 0931-0509
Published online November 2003 | e-ISSN: 1460-2385 | DOI: http://dx.doi.org/10.1093/ndt/gfg398
Thrombin stimulates production of fibronectin by human proximal tubular epithelial cells via a transforming growth factor-β-dependent mechanism

Show Summary Details

Preview

Background. Tubulointerstitial fibrosis contributes to the progression of many forms of glomerular disease and to end-stage renal failure. Inflammatory mediators generated during glomerular injury may induce tubulointerstitial lesions by stimulating tubular cells. Thrombin has multiple biological functions in addition to its role in haemostasis and has been detected in the urine of patients with glomerular diseases. The present study investigated whether thrombin can modulate the production of fibronectin (FN) in cultured human proximal tubular epithelial cells (PTEC).

Methods. Cultured PTEC were incubated with or without thrombin to examine the effect of thrombin on FN production in PTEC. FN and transforming growth factor-β (TGF-β) levels were measured in culture supernatants by enzyme-linked immunosorbent assay (ELISA). Expression of FN mRNA was analysed by reverse transcriptase–polymerase chain reaction. Effects of thrombin on matrix metabolism were examined by enzyme immunoassay for the detection of secreted matrix metalloproteinase (MMP) and its inhibitors (TIMPs) as well as by zymography.

Results. Thrombin stimulated FN secretion in PTEC. Thrombin also stimulated TGF-β secretion in PTEC in a dose-dependent manner. Expression of FN mRNA by PTEC was augmented by thrombin. The stimulatory effect of thrombin on FN secretion was inhibited by neutralizing antibodies against TGF-β but not by an irrelevant antibody. Thrombin-induced FN secretin was also inhibited by thrombin inhibitors, such as antithrombin III, hirudin and argatroban. Although thrombin stimulated TIMP-1 and -2 secretion by PTEC, the stimulatory effect of thrombin on MMP-2 was not statistically significant. Thrombin did not affect the expression of MMP-2 in zymography studies.

Conclusions. We found that thrombin stimulates FN production in PTEC without causing matrix degradation, an effect that may contribute to the formation of tubulointerstitial fibrosis associated with glomerular disease. The stimulatory effect of thrombin on FN production in PTEC is, at least in part, mediated by TGF-β.

Keywords: fibronectin; human proximal tubular epithelial cell; TGF-β; thrombin; tubulointerstitial fibrosis

Journal Article.  4095 words.  Illustrated.

Subjects: Nephrology

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.