6 research outputs found
Identification of microRNAs with Dysregulated Expression in Status Epilepticus Induced Epileptogenesis
<div><p>The involvement of miRNA in mesial temporal lobe epilepsy (MTLE) pathogenesis has increasingly become a focus of epigenetic studies. Despite advances, the number of known miRNAs with a consistent expression response during epileptogenesis is still small. Addressing this situation requires additional miRNA profiling studies coupled to detailed individual expression analyses. Here, we perform a miRNA microarray analysis of the hippocampus of Wistar rats 24 hours after intra-hippocampal pilocarpine-induced Status Epilepticus (H-PILO SE). We identified 73 miRNAs that undergo significant changes, of which 36 were up-regulated and 37 were down-regulated. To validate, we selected 5 of these (10a-5p, 128a-3p, 196b-5p, 352 and 324-3p) for RT-qPCR analysis. Our results confirmed that miR-352 and 196b-5p levels were significantly higher and miR-128a-3p levels were significantly lower in the hippocampus of H-PILO SE rats. We also evaluated whether the 3 miRNAs show a dysregulated hippocampal expression at three time periods (0h, 24h and chronic phase) after systemic pilocarpine-induced status epilepticus (S-PILO SE). We demonstrate that miR-128a-3p transcripts are significantly reduced at all time points compared to the naïve group. Moreover, miR-196b-5p was significantly higher only at 24h post-SE, while miR-352 transcripts were significantly up-regulated after 24h and in chronic phase (epileptic) rats. Finally, when we compared hippocampi of epileptic and non-epileptic humans, we observed that transcript levels of miRNAs show similar trends to the animal models. In summary, we successfully identified two novel dysregulated miRNAs (196b-5p and 352) and confirmed miR-128a-3p downregulation in SE-induced epileptogenesis. Further functional assays are required to understand the role of these miRNAs in MTLE pathogenesis.</p></div
RT-qPCR validation of microarray results.
<p>miRs 196b-5p and 352 were significantly increased and miR-128a-3p was significantly reduced in 24h post-SE hippocampus compared with control group. miRs 10a-5p and 324-3p did not show statistically significant differences. (values are mean±SEM, n = 5-6 in each group, *p < 0.05, Unpaired t test).</p
GO Pathway significantly overrepresented among the miR-196b-5p validated targets.
<p>GO Pathway significantly overrepresented among the miR-196b-5p validated targets.</p
GO Pathway significantly overrepresented among the miR-128a-3p validated targets.
<p>GO Pathway significantly overrepresented among the miR-128a-3p validated targets.</p
Expression patterns of miR-128a-3p, miR-196b-5p and miR-352 during S-PILO-SE induced epileptogenesis.
<p>RT-qPCR measurements of the relative miRs levels (hippocampus) in three different time points after SE-induction (values are mean±SEM, n = 5-6 in each group, *p < 0.05, Bonferroni’s Multiple Comparison Test.</p
Relative expression of miR-128a-3p and miR-196b-5p in hippocampi from epileptic and non-epileptic humans.
<p>RT-qPCR analysis (values are meanSEM, biopsy specimens from TLE-HS patients (n = 10-14) and non-epileptic autopsy samples (n = 4), Mann Whitney test).</p