RESUMEN
Epilepsy is one of the most prevalent complex neurological diseases in both the canine and human species, with the idiopathic form as its most common diagnosis. MicroRNAs (miRNAs) are small, noncoding RNA molecules that play a role in gene regulation processes and appear to be a promising biological target for convulsion control. These molecules have been reported as constituents of the internal content of exosomes, which are small extracellular vesicles released by cells. In this study, exosome samples were isolated from the plasma of 23 dogs, including 9 dogs with epilepsy responsive to treatment, 6 dogs with drug-resistant epilepsy, and 8 control dogs. Plasma exosomes were then characterized by electron transmission microscopy, nanoparticle tracking analysis, and dot blotting. Afterwards, the microRNA-enriched RNA content of exosomes was isolated, and miRNA quantification was performed by quantitative real-time PCR. Seven circulating miRNAs that have been previously described in the literature as potential diagnostic or prognostic biomarkers for epilepsy were evaluated. We observed significant differences in miR-16 (p < 0.001), miR-93-5p (p < 0.001), miR-142 (p < 0.001), miR-574 (p < 0.01), and miR-27 (p < 0.05) levels in dogs with refractory epilepsy compared to the control group. In drug-sensitive epileptic dogs, miR-142 (p < 0.01) showed significant differences compared to healthy dogs. Moreover, distinct levels of miR-16 (p < 0.05), miR-93-5p (p < 0.01), miR-132 (p < 0.05), and miR-574 (p < 0.05) were also found between drug-sensitive and drug-resistant epileptic dogs. Our results present plasma-circulating exosomes as an advantageous source of epileptic biomarkers, highlighting the potential of miRNAs as prognostic and diagnostic biomarkers of canine idiopathic epilepsy.
RESUMEN
Ketogenic diets have been successfully used in people and dogs with idiopathic epilepsy. This study examined the effect of a ketogenic medium chain triglycerides (MCT)- enriched diet administered for one month on the fecal microbiota of epileptic (n = 11) (six with drug-sensitive epilepsy, DSE; five with drug-refractory epilepsy, DRE) and non-epileptic beagle dogs (n = 12). A significant reduction after diet in the relative abundance of bacteria from the Actinobacteria phylum was observed in all dogs. Epileptic dogs showed a higher relative abundance of Lactobacillus compared with non-epileptic dogs at baseline but these differences disappeared after diet. Epileptic dogs also showed a significantly higher abundance of Negativicutes and Selenomonadales after dietary intervention. Baseline microbiota patterns were similar in non-epileptic beagles and dogs with DSE but significantly different from dogs with DRE. In non-epileptic and DSE groups, the MCT diet decreased the relative abundance of Firmicutes and increased that of Bacteroidetes and Fusobacteria, but the opposite effect was observed in dogs with DRE. These results suggest that the MCT diet effect would depend on individual baseline microbiota patterns and that ketogenic diets could help reduce gut microbiota differences between dogs with DRE and DSE.