Visit our Expo - Redox and Inflammation signaling 2012

Session XIV : Transcriptional and translational control Poster XIV, 52
Immunomorphological analysis of RAGE-receptor expression and NFkB-activation in
tissue samples from normal and degenerated intervertebral discs of various ages
A. Nerlich (1), B. Bachmeier (2), E. Schleicher (3), H. Rohrbach (1), G. Paesold (4), N.
Boos (4)
Dept. of Pathology, Academic Hospital Munich-Bogenhausen, Germany,
andreas.nerlich@extern.lrz-muenchen.de
Dept. of Clinical Chemistry Clin. Biochemistry, Univ. Munich, Germany
Dept. Pathobiochemistry, Univ. Tübingen, Germany
Spinal Surgery Unit, Orthopaedic Clinic, Univ. Zürich, Switzerland
Recent studies provided circumstantial evidence that the activation of the RAGE-receptor by
the oxidation-mediated amino acid modification carboxymethyl-lysine (CML) leads to NFkBactivation
and translocation into the nucleus. This leads to the up-regulation of the synthesis
of extracellular matrix molecules along with matrix degrading enzymes. In consequence, the
structure and function of tissue changes. Recent extensive analyses provided good evidence
that the age-associated degeneration of the intervertebral disc is closely associated with both
the alteration of the extracellular disc matrix and the accumulation of oxidation-mediated
CML modification of proteins. Accordingly, pervious own studies have shown significantly
enhanced levels of CML associated with disc degeneration. We therefore investigated the
pattern of RAGE-expression and NFkB-translocation into the nucleus.
For this study, 43 complete cross-sections of complete human lumbar intervertebral discs had
been prepared for the immunohistochemical localization of the RAGE-receptor and NFkBexpression
(both antibodies: Santa Cruz Biotech., CA, USA). The samples covered an age
between fetal (35th weeks of gestation) to senile age (85 years) with well defined macro- and
micromorphological features. The amount of positively labelled cells (RAGE) or nuclei
(activated NFkB) were evaluated morphometrically by light microscopy in the inner and outer
anterior and posterior annulus fibrosus and nucleus pulposus.
No significant expression of RAGE and no obvious activation of NFkB (by translocation into
the nucleus) were seen in fetal, juvenile and young adolescent discs (until age 13). In senile
discs (age 77 – 85 years) RAGE-expression remained elevated, but NFkB activation was
absent. In between, variably high numbers of labelled cells/ nuclei were seen with highest
values ranging between 25 – c. 50% of cells in the nucleus pulposus for RAGE, and 15 – 60
% of nuclei for NFkB with significant correlation between both parameters. In the anterior
and posterior annulus significantly lower values were seen again for both parameters with
more pronounced levels in the inner than the outer annulus.
This study is the first that described activation of the NFkB system in human klumbar
intervertebral discs in vivo. The close correlation between the expression of RAGE and
NFkB-activation suggests that the stimulation of RAGE (e.g. by CML) may induce
transcription factor activation in this system. The association between expression rates for
both parameters and increasing age indicates a potential link between transcription activation
and disc degeneration. This may represent an important mechanism inducing changes in both
cellular and extracellular structures of the disc, potentially prone to therapeutic intervention.
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