036 – THE EXPRESSION OF NGF AND TRKA IN IFLAMMATORY LOCI IN EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS
Nickoleta Delivanoglou (1) – Evangelia Kesidou (1) – Olga Touloumi (1) – Paschalis Theotokis (1) – Kyriaki-Nepheli Poulatsidou (1) – Roza Lagoudaki (1) – Evangelia Nousiopoulou (1) – Evangelia Kofidou (1) – Ioannis Nikolaidis (1) – Christos Bakirtzis (1) – Henrietta-Sygkliti Pelidou (1) – Nikolaos Grigoriadis (1) – Marina Boziki (1) – Ioannis Charalampopoulos (3) – Constantina Simeonidou (2)
Laboratory of Experimental Neurology and Neuroimmunology, AHEPA University Hospital, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece(1) – Laboratory of Experimental Physiology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece (2) – Laboratory of Pharmacology, School of Medicine, University of Crete, Heraklion, Greece (3)
Objectives: Nerve Growth Factor (NGF) and its receptor TrkA, are involved in the interplay of the nervous and immune system in Multiple Sclerosis (MS) and its animal model, Experimental Autoimmune Encephalomyelitis (EAE). We investigated the expression of NGF and TrkA in the inflamed spinal cord in EAE and their immunological relation with inflammation-related markers.
Material and Methods: EAE was induced in C57BL/6 mice inoculated with MOG35-55. Animals were sacrificed for spinal cord tissue collection on days 17 and 50. The expression of NGF and TrkA were examined by immunohistochemistry (IHC) and their co-expression with CD3, Mac-3 and B220 was detected by double immunofluorescence (dIF). IHC and dIF were examined by microscopy and compared to controls (NAIVE).
Results: Immunohistochemistry, on spinal cord sections of EAE and NAIVE animals, showed that in the grey matter, NGF expression is elevated at acute (106.4±7.45, p<0.0001) and at chronic phase (95.55±4.71, p<0.0001) and for TrkA there is a slight increase at acute phase (105,7±4.1, p=0.0109), compared to control group. In the lesioned white matter, the expression during the acute and chronic phase of the NGF (119.5±6.48, p<0.0001 and 138.8±8.28, p<0.0001, respectively) and TrkA (79.86±2.51, p<0.0001 and 77.01±1.44, p<0.0001, respectively) were also upregulated compared to the control group. As far as it concerns immunohistochemistry with anti-CD3, anti-Mac-3 and anti-B220 revealed elevated expression of all three markers in EAE-group for acute and chronic phase respectively, CD3: 143.8±18.60 and 170.70±29.12, Mac-3: 308.3±27.67 and 204.6±24.0, B220: 173.80±17.07 and 94.52±14.29. Macrophages (Mac-3+ cells) co-localize with NGF (26.6±2.7, p<0.0001 and 19±2.6, p<0.0001 respectively), whereas they express TrkA (25.7±1.8, p<0.0001 and 22±1.7, p<0.001 respectively).
Conclusions: The co-expression profile of NGF and TrkA with Mac-3, in areas of inflammatory demyelination indicates their possible involvement in the underlying pathology of degenerated spinal cord during EAE course.