FEATURES OF THE CASPASE-3 EXPRESSION IN THE HIPPOCAMPUS AT THE MODELLING OF THE EXPERIMENTAL ACUTE EPILEPTIC FIT

Epilepsy is one of the most common neurological pathologies, but the biological substrate of the disease is still poorly understood. A few studies have shown that in experimental animals after an epileptic fit there is an increase in the level of some caspases, but the available data are not enough to fully understand the nature of the caspase cascade in epilepsy, and especially its terminal phase. Of particular interest is the analysis of morphological changes in the structures of the hippocampus on the background of an acute epileptic fit in the correlation between neuronal loss and the terminal phase of apoptosis or the quantitative assessment of caspase-3 activity. The aim of the study was the immunohistochemical evaluation of caspase-3 expression in the hippocampus in an experimental model of epilepsy in laboratory mice. The animals were divided into two groups, the animals of the first group (n=28) were intraperitoneally injected with pentilenetetrazole once at a dose of 45 μg/kg to simulate an acute epileptic fit, which was assessed by the modified Racine scale, the second group of animals was the control (n=20). Animals were taken out of the experiment after 3 hours and consecutively on days 1, 3, and 5 from the start of the drug administration for a dynamic study of changes in the hippocampus. Animals were withdrawn from the experiment by introducing high doses of anaesthetic. Animal brain fragments were examined by Nissl staining and caspase-3 expression was quantified by immunohistochemistry in the subregions CA1, CA3 and the dentate gyrus of the hippocampus. 24 hours after the modelling of an acute epileptic fit, the preparations showed signs of hippocampal sclerosis (gliosis, loss of neurons) and an increase in the number of neurons expressing caspase-3 by 2.68 times compared to the number of neurons in the preparations of animals in the control group. As a result of the experiment, it was revealed that the loss of neurons in the hippocampus of the CA3 subregion is associated with an increase in the expression of caspase-3 24 hours after the simulation of an acute generalized seizure using an injection of pentilenetetrazole.

1. Thom M. Review: Hippocampal sclerosis in epilepsy: a neuropathology review. Neuropathol Appl Neurobiol. 2014;40(5):520-543. DOI: 10.1111/nan.12150

2. Chatzikonstantinou A. Epilepsy and the hippocampus. Front Neurol Neurosci. 2014;34:121-142. DOI: 10.1159/000356435

3. Wolinski P, Ksiazek-Winiarek D, Glabinski A. Cytokines and Neurodegeneration in Epileptogenesis. Brain Sci. 2022;12(3):380. DOI: 10.3390/brainsci12030380

4. Beghi E. The Epidemiology of Epilepsy. NED. 2020;54(2):185-191. DOI: 10.1159/000503831

5. Blümcke I, Thom M, Aronica E et al. International consensus classification of hippocampal sclerosis in temporal lobe epilepsy: a Task Force report from the ILAE Commission on Diagnostic Methods. Epilepsia. 2013;54(7):1315-1329. DOI: 10.1111/epi.12220

6. Walker MC. Hippocampal Sclerosis: Causes and Prevention. Semin Neurol. 2015;35(3):193-200. DOI: 10.1055/s-0035-1552618

7. Kandratavicius L, Balista PA, Lopes-Aguiar C et al. Animal models of epilepsy: use and limitations. Neuropsychiatr Dis Treat. 2014;10:1693-1705. DOI: 10.2147/NDT.S50371

8. Löscher W. Animal Models of Seizures and Epilepsy: Past, Present, and Future Role for the Discovery of Antiseizure Drugs. Neurochem Res. 2017;42(7):1873-1888. DOI: 10.1007/s11064-017-2222-z

9. Shimada T, Yamagata K. Pentylenetetrazole-Induced Kindling Mouse Model. J Vis Exp. 2018;(136):56573. DOI: 10.3791/56573

10. Van Erum J, Van Dam D, De Deyn PP. PTZ-induced seizures in mice require a revised Racine scale. Epilepsy & Behavior. 2019;95:51-55. DOI: 10.1016/j.yebeh.2019.02.029

11. Engel T, Henshall DC. Apoptosis, Bcl-2 family proteins and caspases: the ABCs of seizure-damage and epileptogenesis? Int J Physiol Pathophysiol Pharmacol. 2009;1(2):97-115. PMID: 21383882

12. Sun J, Xie C, Liu W et al. The effects of simvastatin on hippocampal caspase-3 and Bcl-2 expression following kainate-induced seizures in rats. International Journal of Molecular Medicine. 2012;30(4):739-746. DOI: 10.3892/ijmm.2012.1076

13. Nguyen TTM, Gillet G, Popgeorgiev N. Caspases in the Developing Central Nervous System: Apoptosis and Beyond. Frontiers in Cell and Developmental Biology. 2021;9. Accessed January 8, 2023. https://www.frontiersin.org/articles/10.3389/fcell.2021.702404

14. Sharangpani A, Takanohashi A, Bell MJ. Caspase Activation in Fetal Rat Brain Following Experimental Intrauterine Inflammation. Brain Res. 2008;1200:138-145. DOI: 10.1016/j.brainres.2008.01.045

15. Zimatkin SM, Bon’ EI. Dark Neurons of the Brain. Neurosci Behav Physi. 2018;48(8):908-912. DOI: 10.1007/s11055-018-0648-7

16. Ahmadpour S, Behrad A, Vega IF. Dark Neurons: A protective mechanism or a mode of death. Journal of Medical Histology. 2019;3(2):125-131. DOI: 10.21608/jmh.2020.40221.1081

17. Ooigawa H, Nawashiro H, Fukui S et al. The fate of Nissl-stained dark neurons following traumatic brain injury in rats: difference between neocortex and hippocampus regarding survival rate. Acta Neuropathol. 2006;112(4):471-481. DOI: 10.1007/s00401-006-0108-2

18. Liu JP, Chang LR, Gao XL, Wu Y. Different expression of caspase-3 in rat hippocampal subregions during postnatal development. Microsc Res Tech. 2008;71(9):633-638. DOI: 10.1002/jemt.20600

19. Basaranlar G, Derin N, Kencebay Manas C et al. The effects of sulfite on cPLA2, caspase-3, oxidative stress and locomotor activity in rats. Food and Chemical Toxicology. 2019;123:453-458. DOI: 10.1016/j.fct.2018.11.021

20. Narkilahti S, Nissinen J, Pitkänen A. Administration of caspase 3 inhibitor during and after status epilepticus in rat: effect on neuronal damage and epileptogenesis. Neuropharmacology. 2003;44(8):1068-1088. DOI: 10.1016/s0028-3908(03)00115-1

21. Baculis BC, Weiss AC, Pang W et al. Prolonged seizure activity causes caspase dependent cleavage and dysfunction of G-protein activated inwardly rectifying potassium channels. Sci Rep. 2017;7(1):12313. DOI: 10.1038/s41598-017-12508-y

22. Tzeng TT, Tsay HJ, Chang L et al. Caspase 3 involves in neuroplasticity, microglial activation and neurogenesis in the mice hippocampus after intracerebral injection of kainic acid. J Biomed Sci. 2013;20(1):90. DOI: 10.1186/1423-0127-20-90