Polenov Russian Scientific Research Institute of Neurosurgery – branch of Almazov National Medical Research Centre, Saint Petersburg, Sankt-Peterburg, Russia
Dr. Darya Sitovskaya
Polenov Russian Scientific Research Institute of Neurosurgery – branch of Almazov National Medical Research Centre, Saint Petersburg, Sankt-Peterburg, Russia
Neuroglial apoptosis and neuroinflammation play an important role in epileptogenesis. The aim of this study is to evaluate neuronal and glial apoptosis in association with neuroinflammation in brain epileptic focus and inflammatory changes in blood in patients with focal drug-resistant epilepsy (DRE). Pathological changes in the temporal lobe in epilepsy (histology, transmission electron microscopy), levels of apoptotic and neuroinflammatory proteins: active caspase-3 (immunohistochemistry), full-length form caspase-3, caspase-9, FAS, FAS-L, NF-kB, TNF-α, p53 (Western blot), and cytokine levels in blood: IL-1β, IL-2, IL-4, IL-7, TNF-α, etc. (multiplex analysis) were studied. In the present work, ultrastructural and immunohistochemical apoptotic signs were found in neurons and oligodendrocytes in the temporal lobe of DRE patients. Levels of proinflammatory cytokines that play a role in apoptosis (TNF-α, FAS, NF-kB) were increased. The blood concentration of IL-4, IL-7, TNF-α is increased and IL-2 is reduced. Oligodendroglial apoptosis has been shown to play an important role in DRE pathogenesis and to explain demyelination. Thus, a comprehensive analysis of revealed changes in the blood and brain in DRE patients showed the neuroinflammation in the epileptic focus, which was combined with the development of apoptosis of glial cells and neurons. This creates conditions for the development of drug resistance and the epilepsy progression.
The European Commission of the International League Against Epilepsy (ILAE) has identified glial mechanisms of seizures and epileptogenesis as top research priorities. The aim of our study was to conduct a comparative analysis of the expression levels of cytoskeletal proteins (glial fibrillar acidic protein (GFAP) and vimentin), protective protein S100, and proapoptotic caspase-3 protein in patients with drug-resistant epilepsy (DRE) associated with focal cortical dysplasia (FCD). We aimed to investigate how the expression levels of these proteins depend on age (both in children and adults), gender, and disease duration, using immunohistochemistry. Nonparametric statistical methods were employed for data analysis. In the epileptic focus area of the cortex and white matter in patients with FCD-associated temporal lobe DRE, a higher level of expression of these proteins was observed. Age and gender differences were found for vimentin and S100. In the early stages of disease development, there was a compensatory sequential increase in the expression of cytoskeletal and protective proteins. In patients with DRE, depending on the disease duration, patterns of development of neurodegeneration were noted, which is accompanied by apoptosis of gliocytes. These results provide insights into epilepsy mechanisms and may contribute to improving diagnostic and treatment approaches.
Molecular chaperones, especially 70 kDa heat shock protein, in addition to their intracellular localization in cancer cells, can be exposed on the surface of the plasma membrane. We report that the membrane-associated chaperone mHsp70 of malignant brain tumors is required for high migratory and invasive activity of cancer cells. Live-cell inverted confocal microscopy of tumor samples from adult (n = 23) and pediatric (n = 9) neurooncologic patients showed pronounced protein expression on the membrane, especially in the perifocal zone. Mass spectrometry analysis of lipid rafts isolated from tumor cells confirmed the presence of the protein in the chaperone cluster (including representatives of other families, such as Hsp70, Hsc70, Hsp105, and Hsp90), which in turn, during interactome analysis, was associated with proteins involved in cell migration (e.g., Rac1, RhoC, and myosin-9). The use of small-molecule inhibitors of HSP70 (PES and JG98) led to a substantial decrease in the invasive potential of cells isolated from a tumor sample of patients, which indicates the role of the chaperone in invasion. Moreover, the use of HSP70 inhibitors in animal models of orthotopic brain tumors significantly delayed tumor progression, which was accompanied by an increase in overall survival. Data demonstrate that chaperone inhibitors, particularly JG98, disrupt the function of mHsp70, thereby providing an opportunity to better understand the diverse functions of this protein and offer aid in the development of novel cancer therapies. Significance: Membrane-bound mHsp70 is required for brain tumor cell migration and invasion and therefore could be employed as a target for anticancer therapies.
Drug-resistance epilepsy (DRE) is a key problem in neurology. It is possible that damage to the blood–brain barrier (BBB) may affect resistance in DRE. The aim of this work was to assess the damage and dysfunction in the BBB in the area of epileptic foci in patients with DRE under conditions of neuroinflammation. The changes to the BBB in temporal lobe epilepsy (by immunohistochemistry and transmission electron microscopy), levels of neuroinflammatory proteins, and cytokine levels in the blood (by multiplex analysis) were studied. Increased levels of vascular endothelial growth factor (VEGF) and growth-regulated protein (GRO), and decreased levels of epidermal growth factor (EGF) in plasma, combined with overexpression of the VEGF-A receptor by endotheliocytes were detected. Malformation-like growths of the basement membrane of the capillaries of the brain complicate the delivery of antiepileptic drugs (AEDs). Dysplasia of the basement membrane is the result of inadequate reparative processes in chronic inflammation. In conclusion, it should be noted that damage to the microcirculatory network of the brain should be considered one of the leading factors contributing to DRE.
1 January 2022 in Russian Journal of Archive of Pathology
Первичные меланоцитарные опухоли центральной нервной системы (ЦНС) встречаются крайне редко и составляют лишь 1% всех меланом и 0,05% первичных опухолей головного мозга. В случае диффузно-инвазивного поражения мягких мозговых оболочек опухолью меланоцитарного происхождения (без признаков экстракраниальных метастазов) образование классифицируется как первичный диффузный менингеальный меланоматоз (ПДММ). ПДММ — крайне редкий подтип злокачественной опухоли ЦНС, с частотой встречаемости 1 случай на 20 млн человек. Несмотря на развитие методов нейровизуализации, в настоящее время морфологическое исследование остается основным и наиболее точным методом верификации меланоцитарных опухолей ЦНС. Сообщаем о летальном случае ПДММ, проявлявшегося эпилептическим синдромом, с быстропрогрессирующим течением.
15 December 2023 in Russian Neurosurgical Journal named after Professor A. L. Polenov
The first attempts to use immunotherapy in the treatment of patients with glioblastoma were not successful enough. This failure was associated with the immunological privilege of the brain, such features of the tumor itself as low mutational load and genetic heterogeneity. Research conducted in recent years has clarified the features of the functioning of the immune system in the patients with glioblastoma. Today, one of the leading factors of immunosuppression is systemic lymphopenia, not only of an iatrogenic nature, but also induced by the tumor itself. We have presented a review on this topic with a description of three clinical cases with an assessment of the lymphocyte subpopulation in the peripheral blood and the infiltration of immune system cells into the tumor. Immunotherapy options for this group of patients are also presented, taking into account the particularities of the functioning of the immune system.