TY - JOUR
T1 - Discovery and Validation of Circulating microRNAs as Biomarkers for Epileptogenesis after Experimental Traumatic Brain Injury–The EPITARGET Cohort
AU - Heiskanen, Mette
AU - Das Gupta, Shalini
AU - Mills, James D.
AU - van Vliet, Erwin A.
AU - Manninen, Eppu
AU - Ciszek, Robert
AU - Andrade, Pedro
AU - Puhakka, Noora
AU - Aronica, Eleonora
AU - Pitkänen, Asla
N1 - Funding Information: This research was funded by The Medical Research Council of the Academy of Finland (Grants 272249, 273909, 2285733-9), The Sigrid Jusélius Foundation, and the European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n°602102 (EPITARGET). Publisher Copyright: © 2023 by the authors.
PY - 2023/2/1
Y1 - 2023/2/1
N2 - Traumatic brain injury (TBI) causes 10–20% of structural epilepsies and 5% of all epilepsies. The lack of prognostic biomarkers for post-traumatic epilepsy (PTE) is a major obstacle to the development of anti-epileptogenic treatments. Previous studies revealed TBI-induced alterations in blood microRNA (miRNA) levels, and patients with epilepsy exhibit dysregulation of blood miRNAs. We hypothesized that acutely altered plasma miRNAs could serve as prognostic biomarkers for brain damage severity and the development of PTE. To investigate this, epileptogenesis was induced in adult male Sprague Dawley rats by lateral fluid-percussion-induced TBI. Epilepsy was defined as the occurrence of at least one unprovoked seizure during continuous 1-month video-electroencephalography monitoring in the sixth post-TBI month. Cortical pathology was analyzed by magnetic resonance imaging on day 2 (D2), D7, and D21, and by histology 6 months post-TBI. Small RNA sequencing was performed from tail-vein plasma samples on D2 and D9 after TBI (n = 16, 7 with and 9 without epilepsy) or sham operation (n = 4). The most promising miRNA biomarker candidates were validated by droplet digital polymerase chain reaction in a validation cohort of 115 rats (8 naïve, 17 sham, and 90 TBI rats [21 with epilepsy]). These included 7 brain-enriched plasma miRNAs (miR-434-3p, miR-9a-3p, miR-136-3p, miR-323-3p, miR-124-3p, miR-212-3p, and miR-132-3p) that were upregulated on D2 post-TBI (p < 0.001 for all compared with naïve rats). The acute post-TBI plasma miRNA profile did not predict the subsequent development of PTE or PTE severity. Plasma miRNA levels, however, predicted the cortical pathology severity on D2 (Spearman ρ = 0.345–0.582, p < 0.001), D9 (ρ = 0.287–0.522, p < 0.001–0.01), D21 (ρ = 0.269–0.581, p < 0.001–0.05) and at 6 months post-TBI (ρ = 0.230–0.433, p < 0.001–0.05). We found that the levels of 6 of 7 miRNAs also reflected mild brain injury caused by the craniotomy during sham operation (ROC AUC 0.76–0.96, p < 0.001–0.05). In conclusion, our findings revealed that increased levels of neuronally enriched miRNAs in the blood circulation after TBI reflect the extent of cortical injury in the brain but do not predict PTE development.
AB - Traumatic brain injury (TBI) causes 10–20% of structural epilepsies and 5% of all epilepsies. The lack of prognostic biomarkers for post-traumatic epilepsy (PTE) is a major obstacle to the development of anti-epileptogenic treatments. Previous studies revealed TBI-induced alterations in blood microRNA (miRNA) levels, and patients with epilepsy exhibit dysregulation of blood miRNAs. We hypothesized that acutely altered plasma miRNAs could serve as prognostic biomarkers for brain damage severity and the development of PTE. To investigate this, epileptogenesis was induced in adult male Sprague Dawley rats by lateral fluid-percussion-induced TBI. Epilepsy was defined as the occurrence of at least one unprovoked seizure during continuous 1-month video-electroencephalography monitoring in the sixth post-TBI month. Cortical pathology was analyzed by magnetic resonance imaging on day 2 (D2), D7, and D21, and by histology 6 months post-TBI. Small RNA sequencing was performed from tail-vein plasma samples on D2 and D9 after TBI (n = 16, 7 with and 9 without epilepsy) or sham operation (n = 4). The most promising miRNA biomarker candidates were validated by droplet digital polymerase chain reaction in a validation cohort of 115 rats (8 naïve, 17 sham, and 90 TBI rats [21 with epilepsy]). These included 7 brain-enriched plasma miRNAs (miR-434-3p, miR-9a-3p, miR-136-3p, miR-323-3p, miR-124-3p, miR-212-3p, and miR-132-3p) that were upregulated on D2 post-TBI (p < 0.001 for all compared with naïve rats). The acute post-TBI plasma miRNA profile did not predict the subsequent development of PTE or PTE severity. Plasma miRNA levels, however, predicted the cortical pathology severity on D2 (Spearman ρ = 0.345–0.582, p < 0.001), D9 (ρ = 0.287–0.522, p < 0.001–0.01), D21 (ρ = 0.269–0.581, p < 0.001–0.05) and at 6 months post-TBI (ρ = 0.230–0.433, p < 0.001–0.05). We found that the levels of 6 of 7 miRNAs also reflected mild brain injury caused by the craniotomy during sham operation (ROC AUC 0.76–0.96, p < 0.001–0.05). In conclusion, our findings revealed that increased levels of neuronally enriched miRNAs in the blood circulation after TBI reflect the extent of cortical injury in the brain but do not predict PTE development.
KW - Animals
KW - Biomarkers
KW - Brain Injuries, Traumatic/pathology
KW - Brain Injuries/complications
KW - Circulating MicroRNA
KW - Disease Models, Animal
KW - Epilepsy/genetics
KW - Male
KW - MicroRNAs/genetics
KW - Rats
KW - Rats, Sprague-Dawley
KW - fluid-percussion injury
KW - plasma
KW - post-traumatic epilepsy
KW - rat
UR - http://www.scopus.com/inward/record.url?scp=85148026058&partnerID=8YFLogxK
UR - https://pure.uva.nl/ws/files/115653670/Supplementary_Data_Discovery_and_Validation_of_Circulating_microRNAs.pdf
U2 - https://doi.org/10.3390/ijms24032823
DO - https://doi.org/10.3390/ijms24032823
M3 - Article
C2 - 36769143
SN - 1661-6596
VL - 24
JO - International journal of molecular sciences
JF - International journal of molecular sciences
IS - 3
M1 - 2823
ER -