Thromb Haemost 2003; 89(05): 926-935
DOI: 10.1055/s-0037-1613480
Cellular Proteolysis and Oncology
Schattauer GmbH

Reactive oxygen species modulate HIF-1 mediated PAI-1 expression: involvement of the GTPase Rac1

Agnes Görlach
1   Experimentelle Kinderkardiologie, Deutsches Herzzentrum München an der Technischen Universität München, Munich, Germany
,
Utta Berchner-Pfannschmidt
2   Max-Planck-Institut für Molekulare Physiologie, Dortmund, Germany
,
Christoph Wotzlaw
2   Max-Planck-Institut für Molekulare Physiologie, Dortmund, Germany
,
Robbert H. Cool
2   Max-Planck-Institut für Molekulare Physiologie, Dortmund, Germany
,
Joachim Fandrey
3   Institut für Physiologie, Universität Essen, Essen, Germany
,
Helmut Acker
2   Max-Planck-Institut für Molekulare Physiologie, Dortmund, Germany
,
Kurt Jungermann
4   Institut für Biochemie und Molekulare Zellbiologie, Georg-August-Universität, Göttingen, Germany
†   deceased May 10, 2002
,
Thomas Kietzmann
4   Institut für Biochemie und Molekulare Zellbiologie, Georg-August-Universität, Göttingen, Germany
› Author Affiliations

Financial support: This study was supported by the Deutsche Forschungsgemeinschaft SFB 402 Teilprojekt A1 and GRK 335 Projekt 6 to TK, by DFG grant GO 709/4-1 to AG and BMBF grant 13N7447/5 to HA.
Further Information

Publication History

Received 31 October 2002

Accepted after revision 26 February 2003

Publication Date:
09 December 2017 (online)

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Summary

The hypoxia-inducible transcription factor HIF-1 mediates upregulation of plasminogen activator inhibitor-1 (PAI-1) expression under hypoxia. Reactive oxygen species (ROS) have also been implicated in PAI-1 gene expression. However, the role of ROS in HIF-1-mediated regulation of PAI-1 is not clear. We therefore investigated the role of the GTPase Rac1 which modulates ROS production in the pathway leading to HIF-1 and PAI-1 induction.

Overexpression of constitutively activated (RacG12V) or dominant-negative (RacT17N) Rac1 increased or decreased, respectively, ROS production. In RacG12V-expressing cells, PAI-1 mRNA levels as well as HIF-1α nuclear presence were reduced under normoxia and hypoxia whereas expression of RacT17N resulted in opposite effects. Treatment with the antioxidant pyrrolidinedithiocarbamate or coexpression of the redox factor-1 restored HIF-1 and PAI-1 promoter activity in RacG12V-cells. In contrast, NFκB activation was enhanced in RacG12V-cells, but abolished by RacT17N. Thus, these findings suggest a mechanism explaining modified fibrinolysis and tissue remodeling in an oxidized environment.

Contributing authors: Agnes Görlach and Thomas Kietzmann contributed equally to this work.