Abstracts

Rationale: In the blood-brain barrier (BBB), the activation of CB1 and CB2 receptors (CB1R and CB2R) has been suggested to protect against damage1,2. The BBB breakdown is associated following brain injuries including epilepsy3. However, it is unknown the expression of CB1R and CB2R in the BBB from subjects with drug-resistant temporal lobe epilepsy (DRTLE). The aim of this study was to characterize the expression of CB1R and CB2R in microvessels (MVs) of BBB obtained from DRTLE patients.< REFERENCES:1Lu TS, Avraham HK, Seng S, Tachado SD, Koziel H, Makriyannis A, Avraham S. Cannabinoids inhibit HIV-1 Gp120-mediated insults in brain microvascular endothelial cells. J Immunol. 2008. 181(9):6406-16. 2Zhang H, Hilton DA, Hanemann CO, Zajicek J. Cannabinoid receptor and N-acyl phosphatidylethanolamine phospholipase D--evidence for altered expression in multiple sclerosis. Brain Pathol. 2011;21(5):544-57. 3 van Vliet EA, Aronica E, Gorter JA. Blood-brain barrier dysfunction, seizures, and epilepsy. Semin Cell Dev Biol. 2015; 38:26-34. Methods: The samples of the hippocampus and temporal neocortex of DRTLE patients (n=12) were dissected and immediately frozen and kept at -70 °C until processing. The results obtained were compared to autopsies (n=12). MVs were isolated through the homogenization and centrifugation of brain tissue. Subsequently, MVs were processed to determine the protein expression of CB1R and CB2R by western blot. Results: Our results showed a decrease in the expression of CB1R and CB2R in the hippocampus compared to autopsies (61%, p<0.001; 74%, p<0.01, respectively). In contrast, temporal neocortex showed a high protein expression (CB1R, 86%, p<0.01; CB2R, 149%, p<0.01). These changes did not correlate with clinical data. Conclusions: The present study provides for the first time the expression of CB1R and CB2R in the MVs from DRTLE patients. The protein expression of CB1R and CB2R depended on the brain area evaluated and these modifications could participate in the alterations of the integrity of BBB, which are associated with epilepsy. Further in vitro experiments are necessary to determine the specific role of CB1R and CB2R in the integrity of BBB in patients with DRTLE. Funding: The study was carried out with the support of the National Council of Science and Technology (CONACyT) through scholarship number 347414 and grant 261481.