gms | German Medical Science

28. Wissenschaftlicher Kongress der Deutschen Hochdruckliga

24. bis 27.11.2004, Hannover

Upregulation of a local MMP induction/activation system increased gelatinolytic activity in murine viral myocarditis

Hochregulation eines lokalen MMP-Induktions/Aktivierungs-systems erhöht die gelatinolytischer Aktivität in muriner Myokarditis

Meeting Abstract (Hypertonie 2004)

  • S. Leschka - Charité Universitätsmedizin Berlin (Berlin, D)
  • S. Rutschow - Charité Universitätsmedizin Berlin (Berlin, D)
  • K. Puhl - Charité Universitätsmedizin Berlin (Berlin, D)
  • M. Pauschinger - Charité Universitätsmedizin Berlin (Berlin, D)

Hypertonie 2004. 28. Wissenschaftlicher Kongress der Deutschen Hochdruckliga. Hannover, 24.-27.11.2004. Düsseldorf, Köln: German Medical Science; 2005. Doc04hochP48

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/hoch2004/04hoch048.shtml

Published: August 10, 2005

© 2005 Leschka et al.
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Outline

Text

Introduction: Matrix remodeling is a major topic in heart failure. In patients with DCM and ICM is associated with upregulation of a local induction / activation system formed by EMMPRIN (extracellular matrix metalloproteinase inducer; basignin in mice) as inductor of MMP transcription and MT-MMP (membrane-type matrix metalloproteinase) as activator of translated proMMPs. This system could degrade pericellular matrix but also influences the surrounding tissue by inducting and activating mobile MMPs. It is known to be regulated by inflammatory cytokines but seems to be resistant to endogenous inhibitors like TIMP. However, the expression of this system is not yet studied in myocarditis.

Methods: Therefore 8 weeks old BALB/c mice were infected intraperitoneally with 5 x 105 PFU CVB3 (n=14) or sham-infected (n=10). The examination time-point was 10 days after infection. In all mice EMMPRIN, MT1-MMP, MMP-2 and MMP-9 were analyzed by semiquantitative RT-PCR and gelatinolytic activity was measured using zymography. Statistical analysis was performed using one-way ANOVA.

Results: EMMPRIN, MT1-MMP, MMP-2 and MMP-9 mRNA abundance were significantly induced compared to controls. Gelatinolytic activity of MMP-2 was 3.8 fold and of MMP-9 was 15 fold higher in infected mice. Moreover, the mRNA expression of MT1-MMP was significantly correlated to gelatinolytic activity.

Conclusion: The acute phase of viral myocarditis in mice is associated with an upregulation of the EMMPRIN / MT1-MMP system, which leads to an increase in mRNA expression and activity of MMP-2 and MMP-9. Due to its resistence to TIMP this may be responsible for uncontrolled matrix degradation and LV dysfunction.

Figure 1 [Fig. 1]