Stx2 from enterohemorrhagic Escherichia coli produces cerebellar impairment of the vascular unit with inflammatory involvement

VANINA GISELLE VELARDO; CLARA VALENTINA BERDASCO; FERNANDO CORREA; ADRIANA CANGELOSI; PATRICIA A. GEOGHEGAN; GOLDSTEIN JORGE

Congreso; XXXIV Reunión Anual SAN 2019; 2019

Hemolytic uremic syndrome (HUS) is a triad of events that includes thrombocytopenia, microangiopathic hemolytic anemia and acute renal failure caused by Shiga toxin producing Escherichia coli (STEC). Also, HUS produces neurologic alterations. It has been observed that Shiga toxin 2 (Stx2) produces deficits of coordination and equilibrium in patients which suggests cerebellar impairment. Furthermore, we have characterized a model of injury in mice that mimicked clinical impairment of the cerebellum (Front. Microbiol.7:133.doi:10.3389/fmicb.2016.00133). The aims of this study were to determine whether Stx2 causes cell damage in an inflammatory frame in the cerebellum. To determine this, male Swiss NIH mice (n=4) were injected intravenously with 1ηg of Stx2 per mice or 100 µl of saline solution (Control group). After 2 and 4 days of treatment, fixed brains were subjected to immunostaining with lectins to determine the microvasculature profile, immunofluorescence with anti-GFAP and anti-MBP to determine reactive astrocytes and myelin oligodendrocytes conservation state respectively. Images were captured from a confocal microscope and analyzed through the software ImageJ (NIH). To determinate the inflammatory profile, an ELISA test was employed to measure TNFα and IL-10.Stx2 was able to reach the Purkinje and granular cerebellar layers and damaged the endothelial cells after 4 days. The statistical results analyzed by Student's t-test showed thatStx2 significantly: i. decreased the area occupied by the microvasculature (12.58 ± 0.73 Control vs 7.71 ± 0.72 Stx2, day 2, and 12.9 ± 0.5 Control vs 10.03 ± 0.3 Stx2 day 4, in µm2, p