ANTI-INFLAMMATORY AGENTS RESCUE NEURONAL DAMAGE AND MOTOR DEFICITS FROM SHIGA TOXIN 2 AND LIPOPOLYSACCHARIDE IN THE BRAIN STRIATUM OF RODENTS.

PINTO ALIPIO; DAVID ARENAS; CANGELOSI ADRIANA; GEOGHEGAN PATRICIA; BRENER GABRIELA; GOLDSTEIN JORGE

Boston, Massachusetts

Simposio; 9th Triennial International Symposium on Shiga Toxin (Verocytotoxin)-producing Escherichia coli (VTEC) meeting; 2015

Introduction: The striatum isinvolved in central motor pathways and is frequently affected in patientsinfected with EHEC. In addition to Stx2, LPS is secreted by the bacteria and may also contribute to the observedstriatal dysfunction. The aim of this study was to determine: i) whether LPSexacerbates the deleterious effect of Stx2, ii) whether Stx2 alters the motor performance,and iii) the existence of a pro-inflammatory component. Methods: NIH male mice wereinjected intravenously with Stx2+LPS or Stx2 or LPS or vehicle (control). Inaddition the same described groups were treated with Dexamethasone. Mice wereperfused with fixative solution. Their brains were subjected to immunofluorescencewith an anti-NeuN (Neuronal nuclei marker), anti-MAP2 to identify fibers and anti-Gb3(Stx2 receptor). Open field test were assayed to study motor performance. Also SDmale rats were injected intracerebroventricular with Stx2 (20 pg/gr) and Stx2+Etanercept(3.10 ηM, soluble TNF-α receptor) to immunolocalize Stx2 in striatal neurons byimmuno-gold electron microscopy. Results and Discussion: Stx2+LPS maximallyincreased the neuronal damage (34+4%),  decreased the expression levels of MAP2 (31+0.57 in arbitrary units [AU]) andincreased the expression levels of Gb3 (85+7.57 AU). Mice treated with Stx2+LPSshowed an altered motor performance (64+11% less) incomparison to controls. Dexamethasone significantly reverted the changes observedon NeuN, MAP2 and Gb3 expresion and in motor performace. Etanercept reducedthe damaged produced by Stx2, and reduced the immuno-gold particles thatcorresponded to Stx2 into striatal neurons (P<0.05 by ANOVA-Bonferroni posthoc test). We concluded that Stx2 alters striatal  neurons and motor performance;  LPS enhances the deleterious action of Stx2; Dexamethasoneand Etanercept treatments determined a pro-inflammatory participation generatedby these toxins. Implications: The observed pro-inflammatorycomponent should be taken into account in order to establish new studies and possibletherapies to treat this encephalopathy.