APOPTOSIS OF BRAIN CELLS IN EPILEPTIC FOCUS AT PHAPMACRESISTANT TEMPORAL LOBE EPILEPSY

Relevance. Search of the causes of epilepsy and development of new methods of its correction is the most important problem of modern neurology. Studies in recent years focus on examining the role of neuronal apoptosis in epilepsy, the question of the death of glial cells remains poorly understood. However, it is the interaction of neurons with glia that modulates physiological brain function and underlies many neurological diseases, indicating the importance of comprehensive study of the morphological and functional status of these cells in epilepsy.

Purpose. To assess the signifi cance of apoptotic death of neurons and glia in the pathogenesis of pharmacoresistant temporal lobe epilepsy by the expression of caspase-3 in brain cells and ultrastructural manifestations.

Materials and methods. The objects of the study are the samples of the cortex and white matter of the brain in the area of epileptic foci from 20 patients with pharmacoresistant temporal lobe epilepsy. The material for the comparison group obtained at autopsy from 6 patients without epilepsy. Performed studies were immunohistochemical reactions with antibodies to caspase-3 and ultrastructural biopsy analyses.

Results. In every case (100%) patients with E revealed the expression of caspase-3 in gliocytes with predominant localization in the cortex of the temporal lobe. The expression of caspase-3 in neurons has been detected in 20% of observations in single cells. In the comparison group, the expression of caspase-3 was observed only sporadically in a cortical gliocytes. Using electron microscopy we identifi ed a large number of neurons in the cortex with signs of apoptosis at different stages of this process’ development. Apoptotic changes in glial cells were predominantly observed in oligodendrocytes both in the cortex and white matter of the brain.

Conclusion. Detected expression of caspase-3 in gliocytes of the cortex and white matter of epileptic foci attests to the active participation of glia in the pathogenesis of epilepsy. By electron microscopy we found that the majority of apoptotically dying glial cells are oligodendrocytes, that in particular explains the known phenomenon of myelin damage in epileptic foci. As a fact, electron microscopic detection of a large number of apoptosis neurons in biopsies of the cortex with lowlevel expression of caspase-3 in them may indicate a different nature of neuronal apoptosis. Thus, glio-neuronal apoptosis in pharmacoresistant epilepsy has a signifi cant manifestation, and this affects the progression of the disease, creating conditions for the development of status epilepticus and cognitive disorders. Further study of this issue offers the prospect of new therapeutic strategies in the treatment of epilepsy.

1. Khachatryan VA, Bersnev VP, Shershever AS et al. Diagnostics and treatment of progredient forms of epilepsy. Desyatka, 2008. p. 264. In Russian [Хачатрян В.А., Берснев В. П., Шершевер А. С. и др. Диагностика и лечение прогредиентных форм эпилепсии. СПб.:Десятка, 2008. с. 264].

2. Bergin P, Sadleir L, Legros B et. al. An International Pilot Study of an Internet-Based Platform to facilitate clinical research in epilepsy. Epilepsia. 2012; 53: 1829–1835.

3. Henshall D.C., Engel T. Contribution of apoptosis-associated signaling pathways to epileptogenesis: lessons from Bcl-2 family knockouts. Frontiers in Cellular Neuroscience. 2013; 7: Article 110.

4. Sokolova TV, Zabrodskaya YuM, Bazhanova ED et al. The role of glionneuronal apoptosis in the pathogenesis of pharmacoresistant epilepsy. Neurosurgery and neurology of childhood. 2015; 4(46): 71-84. In Russian [Соколова Т.В., Забродская Ю.М., Бажанова Е.Д. и др. Роль глионейронального апоптоза в патогенезе фармакорезистентной эпилепсии. Нейрохирургия и неврология детского возраста. 2015, 4(46): 71-84].

5. Simon D Shorvon. Handbook of Epilepsy Treatment. Wiley-Blackwell. 2010. 300 p.

6. Ryabukha NP, Bersnev VP. Multifocal epilepsy (etiopathogenesis, clinic, diagnosis and surgical treatment). SPb.: RNHI, 2009. p. 216. In Russian [Рябуха Н. П., Берснев В.П. Многоочаговая эпилепсия (этиопатогенез, клиника, диагностика и хирургическое лечение). СПб.: РНХИ, 2009. с. 216].

7. Hader WJ, Tellez-Zenteno J, Metcalfe A et al. Complications of epilepsy surgery – asystematic review of focal surgical resections and invasive EEG monitoring. Epilepsia. 2013; 54: 840–847.

8. Kasumov VR, Bersnev VP, Stepanova TS. The method of extracerebral electrical stimulation in the system of surgical treatment of patients with pharmacoresistant epilepsy. Neurological herb of Bechterev VM. 2009; XLI (3): 41-44. In Russian [Касумов, В.Р., Берснев В.П., Степанова Т.С. и др. Метод внемозговой электростимуляции в системе хирургического лечения больных с фармакорезистентной эпилепсией. Неврол. вестн. им. В.М. Бехтерева. 2009, XLI(3): 41–44].

9. Sloviter, RS. Progress on the issue of excitotoxic injury modi- fication vs. real neuroprotection; implications for post-traumatic epilepsy. Neuropharmacology. 2011; 61: 1048–1050.

10. Crunelli V, Carmignoto G, Steinhäuser C. Novel astrocyte targets: new avenues for the therapeutic treatment of epilepsy. Neuroscientist. 2015; 21(1): 62-83.

11. Gaykova ON, Paramonova NM, Suvorov AV. The value of white matter damage in the brain in the pathogenesis of locally caused epilepsy. Russian Neurosurgical Journal. 2011; 3(1): 19-24. In Russian [Гайкова О.Н., Парамонова Н.М., Суворов А.В. Значение повреждения белого вещества головного мозга в патогенезе локально обусловленной эпилепсии. Рос. Нейрохирург. журн. 2011, 3 (1): 19-24].

12. Bedner P, Dupper A, Huttmann K et. al. Astrocyte uncoupling as a cause of human temporal lobe epilepsy. Brain. 2015; 136: 1208-1222.

13. Douglas A. Coulter, Christian Steinhauser. Role of Astrocytes in Epilepsy. Cold Spring Harb Perspect Med. 2015; 5(3):a022434

14. Narkilahti S, Pirttila TJ, Lukasiuk K et. al. Expression and activation of caspase 3 following status epilepticus in the rat. Eur J Neurosci. 2003; 18(6): 1486–1496.

15. Noebels J, Avoli M, Rogawski M et. al. Jasper's basic mechanisms of the epilepsies. Oxford University Press. 2012. 1264p.

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

17. Veresov VG. Structural biology of apoptosis. Minsk: Belorus. Nauka, 2008; p.200. In Russian [Вересов В.Г. Структурная биология апоптоза. Минск: Белорус. Наука, 2008. с. 398].

18. Yunkerov VI, Grigoriev SG. Mathematical-statistical processing of medical research data. SPb: VMedA, 2005. p. 292. In Russian [Юнкеров В.И., Грирорьев С.Г. Математико-статистическая обработка данных медицинских исследований. Санкт-Петербург: ВМедА, 2005. с. 292].

19. Devinsky O, Vezzani A, Najjar S et al. Glia and epilepsy: excitabilbty and inflammation. Trends in Neurosciences. 2013; 36 (3): 174-84.

20. Medvedev YuV, Bersnev VP, Kasumov VR et al. Effect of the degree of severity of brain gliosis on the severity of the course of the disease in patients with medically-resistant forms of locally caused epilepsy. Neurosurgery. 2010; 4: 65-90. In Russian [Медведев Ю.А., Берснев В.П., Касумов В.Р. и др. Влияние степени выраженности глиоза мозга на тяжесть течения заболевания у больных с медикаментозно–резистентными формами локально обусловленной эпилепсии. Нейрохирургия. 2010, 4: 65 – 90].

21. Crunelli V, Carmignoto G, Steinhäuser C. Novel astrocyte targets: new avenues for the therapeutic treatment of epilepsy. Neuroscientist. 2015; 21(1): 62-83.

22. Novozhilova AP, Gaikova ON. Cell gliosis of a white substance of the human brain and its significance in the pathogenesis of focal epilepsy. Morphology. 2001; 2: 20-24. In Russian [Новожилова А.П., Гайкова О.Н. Клеточный глиоз белого вещества большого мозга человека и его значение в патогенезе очаговой эпилепсии. Морфология. 2001, 2: 20-24].

23. Kalinichenko SG, Dudina YuV, Duzen IV et al. Induction of NO synthase and glial acidic fibrillar protein in astrocytes of the temporal cortex of rats with audiogenic epileptiform response. Morphology. 2004; 125 (3): 68-73. In Russian [Калиниченко С.Г., Дудина Ю.В., Дюйзен И.В. и др. Индукция NO-синтазы и глиального кислого фибриллярного белка в астроцитах височной коры крыс с аудиогенной эпилептиформной реакцией. Морфология. 2004, 125 (3): 68-73].

24. Manto M, Oulad ben Taib N, Luft AR. Modulation of excitability as an early changes leading to structural adaptation in the motor cortex. J. Neurosci. Res. 2006; 83: 177-180.

25. Dudina JV. Symptomatic temporal lobe epilepsy. Vladivostok, Reya, 2008; p.300. In Russian [Дудина Ю.В. Симптоматическая височная эпилепсия. Владивосток: Рея, 2008. с. 300].

26. Liou AKF., Clark RS, Henshall DC. To die or not to die for neurons in ischemia, traumatic brain injury and epilepsy: a review on the stress-activated signaling pathways and apoptotic pathways. Prog. Neurobiol. 2003; 69: 103–142.

27. Henshall D.C., Simon R. Epilepsy and apoptosis pathways. J. of Cerebral Blood Flow and Metabolism. 2005; 25: 1557–1572.

28. Hu X, Wang JY, Gu R et al. The relationship between the occurrence of intractable epilepsy with glial cells and myelin sheath – an experimental study. Eur Rev Med Pharmacol Sci. 2016; 20 (21): 4516-4524.

29. Henshall DC, Clark RS, Adelson PD et al. Alterations in bcl-2 and caspase gene family protein expression in human temporal lobe epilepsy. Neurology. 2000; 55 :250–257.

30. Lapato AS, Szu JI, Hasselmann JPC et al. Chronic demyelination-induced seizures. Neuroscience. 2017; 27(346): 409-422.

31. Luo Y, Hu O, Zhang Q et al. Alterations in hippocampal myelin and oligodendrocyte precursor cells during epileptogenesis. Brain Res. 2015; 19(1627): 154-64.

32. Kıray H, Lindsay S, Hosseinzadeh S et al. The multifaceted role of astrocytes in regulating myelination. Experimental Neurology. 2016, 283:541–549.