Brain, Vol. 124, No. 9, 1743-1753, September 2001
Raija L. P. Lindberg1, Corline J. A. De Groot3, Lisette Montagne3, Peter Freitag2, Paul van der Valk3, Ludwig Kappos2 and David Leppert1,2
1 Departments of Research and 2 Neurology, University Hospitals Basel, Switzerland and the 3 Department of Pathology, Division of Neuropathology, University Hospital Vrije Universiteit, MS Centre for Research and Care, The Netherlands
Correspondence to: Dr R. L. P. Lindberg, Departments of Research and Neurology, University Hospitals, Pharmazentrum, Klingelbergstrasse 50, CH-4056 Basel, Switzerland E-mail: Raija.Lindberg@unibas.ch
In multiple sclerosis, matrix metalloproteinases (MMPs) are effectors of crucial pathogenetic steps, such as blood–brain barrier breakdown, invasion of brain parenchyma by immune cells and demyelination.
However, only limited data are available on the types of MMPs induced in the course of multiple sclerosis, and on the role of their endogenous antagonists, the tissue inhibitors of metalloproteinases (TIMPs).
We quantified the transcriptional expression of six MMPs and the four TIMPs in lesions and in normal appearing white matter (NAWM) from post-mortem multiple sclerosis brain tissue by real-time polymerase chain reaction, and compared levels with those in brain tissue from six control patients without neurological disease.
The mRNA expression of MMP-7 and -9, but not of other metalloproteinases [MMP-2 and -3, and tumour necrosis factor (TNF)--converting-enzyme] was equally upregulated throughout all stages of lesion formation with active inflammation, and in most of matched NAWM tissue.
The transcription of cytokines TNF-/ß and IL (interleukin)-2, known modulators of MMPs, was upregulated only in distinct stages of lesion formation, while their receptors were not induced at all, which suggests that additional signalling molecules participate in the sustained upregulation of MMP-7 and -9 in multiple sclerosis.
None of the TIMPs showed a significant
induction over baseline expression of controls. We hypothesize that an
imbalance between MMP and TIMP expression may cause a persistent proteolytic
overactivity in multiple sclerosis, that may be a factor for continuous
tissue destruction, and hence for secondary disease progression.
Copyright © 2001 Oxford University
Copyright © 2001 Oxford University Press