The relationship between inflammatory markers and hippocampal and extra-hippocampal atrophy patterns in patients with temporal lobe epilepsy

Orientadores: Fernando Cendes, Ana Carolina CoanTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: Introdução: A epilepsia atinge 1 a 2 % da população mundial, sendo a epilepsia de lobo temporal associada a esclerose hipocampal (ELT-EH) a forma mais frequente em adultos. Estudos de imagem já determinaram que a ELT-EH apresenta redução volumétrica cerebral difusa, não sendo restrita à região do hipocampo. Há evidências de que a inflamação tem um importante papel na neuroexcitabilidade e que alterações na regulação inflamatória podem gerar degeneração neuronal e induzir crises convulsivas Objetivos: Definir a associação de marcadores inflamatórios séricos e epilepsias, além de características clínicas, de EEG e padrões de alteração de neuroimagem em pacientes com ELT. Materias e Métodos: Foram incluídos no estudo 490 pacientes com diagnóstico clínico e eletroencefalográfico de epilepsia e um grupo de 166 controles sem doenças neurológicas. Os pacientes foram divididos entre os com ELT (246) e pacientes com outras epilepsias. Os indivíduos foram submetidos a coleta de sangue para a avaliação dos marcadores inflamatórios e 86 desses realizaram ressonância magnética (RM) de crânio. O volume de estruturas subcorticais e espessura de regiões corticais foram analisadas pelo programa FreeSurfer. Os marcadores inflamatórios (IL-1, IL-2, IL-4, IL-6, IL-10, IL-17, TNF? e seus receptores sTNFr1 e sTNFr2, BDNF, CTNF, IFN?, NGF, GDNF) foram analisados de maneira cega aos dados clínicos pelas técnicas Enzyme-Linked Immunosorbent Assay (ELISA) e Cytometric Bead Array (CBA). Resultados: Os fatores inflamatórios não estão correlacionados com a idade e gênero dos indivíduos e nem com o tempo de doença dos pacientes (r>0,3; p>0,05). Os níveis séricos de BDNF, NGF, sTNFr2 e a NT3 foram elevados enquanto que os níveis de TNF, sTNFr1, IFN? e das interleucinas foram reduzidos quando avaliamos os pacientes, em geral ou os grupos ELT e outras epilepsias em relação aos controles. Mesmo padrão foi observado quando avaliados apenas os pacientes com malformação do desenvolvimento cortical, exceto o sTNR1 e IL10 que não foram significativos nessa última análise. O CNTF, NT4/5 e GDNF não foram diferentes entre pacientes e controles. O sTNFr2 se demonstrou um bom marcador para diferenciar pacientes e controles (curva ROC com AUC de 0,858). Analisando apenas os pacientes com ELT, O GDNF foi maior nos pacientes com pouca atividade epileptiforme ao EEG. O IL2 e o IL4 foram elevados nos pacientes com maior frequência de crises. Em relação à imagem, o TNF? sérico apresentou correlação inversa ao volume do tálamo ipsilateral. Discussão: Nosso estudo é um dos primeiros a avaliar uma extensa coorte de pacientes e realizar uma avaliação exploratória sobre a relação de marcadores inflamatórios, dados clínicos e de neuroimagem. Os marcadores inflamatórios apresentam diferentes papéis no sistema nervoso central e sua medição sérica nos ajuda a compreender melhor o papel desses nas epilepsias. Conclusão: Os marcadores inflamatórios estão claramente envolvidos na epilepsia e na perda neuronal, porém são necessários estudos específicos para compreender se estes são epifenômenos ou consequências das crisesAbstract: Introduction: Epilepsy affects 1% to 2% of the world population and temporal lobe epilepsy associated with hippocampal sclerosis (TLE-HS) is the most common epilepsy in adults. Imaging studies have already demonstrated that TLE patients present diffuse gray and white matter atrophy, not restricted to hippocampal region. Inflammation perform an important role in neuroexcitability. Changes on inflammatory regulation can lead to neuronal degeneration and induce seizures. Objectives: To define the association of serum inflammatory markers and epilepsies, as well as clinical characteristics, EEG and neuroimaging patterns in patients with TLE. Subjects and Methods: The study included 490 patients with clinical and electroencephalographic (EEG) diagnosis of epilepsy and a group with 166 controls without neurological diseases. The patients were classified as TLE-HS (246) and other epilepsies. All participants were invited to perform blood sampling (blood serum for inflammatory markers) and 86 performed magnetic resonance imaging (MRI). MRI cortical thickness and subcortical structures were analyzed with FreeSurfer software. The blood serum analysis of IL-1, IL-2, IL-4, IL-6, IL-10, IL-17, TNF? ,sTNFr1, sTNFr2, BDNF, CTNF, IFN?, NGF, GDNF was performed by Enzyme-Linked Immunosorbent Assay (ELISA) and Cytometric Bead Array (CBA). Results: The inflammatory markers did not present correlation with age and gender, or with epilepsy duration. The blood serum levels of BDNF, NGF, sTNFr2 e a NT3 were higher while TNF, sTNFr1, IFN? and interleukines were reduced in patients with epilepsy, TLE-HS and other epilepsies when compared with controls. The same pattern was observed in patients with malformation of cortical development, except for sTNFr1 and IL10. The CTNF, NT4/5 and GDNF were not different between patients and controls in any group. In ROC analysis the sTNFr2 was a good marker to separate patients from controls (AUC =0,858). Considering just patients, the GDNF presented higher serum levels in patients with less interictal epileptiform activity at EEG; and blood serum IL2 and IL4 were higher in patients with more frequent seizures. TNF? presented an inverse correlation with ipsilateral thalamus volume. Discussion: Our study is one of the first to evaluate an extensive cohort of patients and perform an exploratory assessment on the relationship between inflammatory markers, clinical data and imaging. Inflammatory markers play different roles in central nervous system and their serum measurement helps in better comprehending their relationship with epilepsy. Conclusion: The inflammatory markers are associated with epilepsy, but more specific studies are necessary to determine if they are epiphenomena or consequence of seizuresDoutoradoFisiopatologia MédicaDoutora em Ciências2015/17066-0;FAPESPCAPE

HMGB1: A Common Biomarker and Potential Target for TBI, Neuroinflammation, Epilepsy, and Cognitive Dysfunction

High mobility group box protein 1 (HMGB1) is a ubiquitous nuclear protein released by glia and neurons upon inflammasome activation and activates receptor for advanced glycation end products (RAGE) and toll-like receptor (TLR) 4 on the target cells. HMGB1/TLR4 axis is a key initiator of neuroinflammation. In recent days, more attention has been paid to HMGB1 due to its contribution in traumatic brain injury (TBI), neuroinflammatory conditions, epileptogenesis, and cognitive impairments and has emerged as a novel target for those conditions. Nevertheless, HMGB1 has not been portrayed as a common prognostic biomarker for these HMGB1 mediated pathologies. The current review discusses the contribution of HMGB1/TLR4/RAGE signaling in several brain injury, neuroinflammation mediated disorders, epileptogenesis and cognitive dysfunctions and in the light of available evidence, argued the possibilities of HMGB1 as a common viable biomarker of the above mentioned neurological dysfunctions. Furthermore, the review also addresses the result of preclinical studies focused on HMGB1 targeted therapy by the HMGB1 antagonist in several ranges of HMGB1 mediated conditions and noted an encouraging result. These findings suggest HMGB1 as a potential candidate to be a common biomarker of TBI, neuroinflammation, epileptogenesis, and cognitive dysfunctions which can be used for early prediction and progression of those neurological diseases. Future study should explore toward the translational implication of HMGB1 which can open the windows of opportunities for the development of innovative therapeutics that could prevent several associated HMGB1 mediated pathologies discussed herein

Transcriptome analyses of the cortex and white matter of focal cortical dysplasia type II: Insights into pathophysiology and tissue characterization

IntroductionFocal cortical dysplasia (FCD) is a common cause of pharmacoresistant epilepsy. According to the 2022 International League Against Epilepsy classification, FCD type II is characterized by dysmorphic neurons (IIa and IIb) and may be associated with balloon cells (IIb). We present a multicentric study to evaluate the transcriptomes of the gray and white matters of surgical FCD type II specimens. We aimed to contribute to pathophysiology and tissue characterization.MethodsWe investigated FCD II (a and b) and control samples by performing RNA-sequencing followed by immunohistochemical validation employing digital analyses.ResultsWe found 342 and 399 transcripts differentially expressed in the gray matter of IIa and IIb lesions compared to controls, respectively. Cholesterol biosynthesis was among the main enriched cellular pathways in both IIa and IIb gray matter. Particularly, the genes HMGCS1, HMGCR, and SQLE were upregulated in both type II groups. We also found 12 differentially expressed genes when comparing transcriptomes of IIa and IIb lesions. Only 1 transcript (MTRNR2L12) was significantly upregulated in FCD IIa. The white matter in IIa and IIb lesions showed 2 and 24 transcripts differentially expressed, respectively, compared to controls. No enriched cellular pathways were detected. GPNMB, not previously described in FCD samples, was upregulated in IIb compared to IIa and control groups. Upregulations of cholesterol biosynthesis enzymes and GPNMB genes in FCD groups were immunohistochemically validated. Such enzymes were mainly detected in both dysmorphic and normal neurons, whereas GPNMB was observed only in balloon cells.DiscussionOverall, our study contributed to identifying cortical enrichment of cholesterol biosynthesis in FCD type II, which may correspond to a neuroprotective response to seizures. Moreover, specific analyses in either the gray or the white matter revealed upregulations of MTRNR2L12 and GPNMB, which might be potential neuropathological biomarkers of a cortex chronically exposed to seizures and of balloon cells, respectively

Transcriptome analyses of the cortex and white matter of focal cortical dysplasia type II: Insights into pathophysiology and tissue characterization

Introduction Focal cortical dysplasia (FCD) is a common cause of pharmacoresistant epilepsy. According to the 2022 International League Against Epilepsy classification, FCD type II is characterized by dysmorphic neurons (IIa and IIb) and may be associated with balloon cells (IIb). We present a multicentric study to evaluate the transcriptomes of the gray and white matters of surgical FCD type II specimens. We aimed to contribute to pathophysiology and tissue characterization. Methods We investigated FCD II (a and b) and control samples by performing RNA-sequencing followed by immunohistochemical validation employing digital analyses. Results We found 342 and 399 transcripts differentially expressed in the gray matter of IIa and IIb lesions compared to controls, respectively. Cholesterol biosynthesis was among the main enriched cellular pathways in both IIa and IIb gray matter. Particularly, the genes HMGCS1, HMGCR, and SQLE were upregulated in both type II groups. We also found 12 differentially expressed genes when comparing transcriptomes of IIa and IIb lesions. Only 1 transcript (MTRNR2L12) was significantly upregulated in FCD IIa. The white matter in IIa and IIb lesions showed 2 and 24 transcripts differentially expressed, respectively, compared to controls. No enriched cellular pathways were detected. GPNMB, not previously described in FCD samples, was upregulated in IIb compared to IIa and control groups. Upregulations of cholesterol biosynthesis enzymes and GPNMB genes in FCD groups were immunohistochemically validated. Such enzymes were mainly detected in both dysmorphic and normal neurons, whereas GPNMB was observed only in balloon cells. Discussion Overall, our study contributed to identifying cortical enrichment of cholesterol biosynthesis in FCD type II, which may correspond to a neuroprotective response to seizures. Moreover, specific analyses in either the gray or the white matter revealed upregulations of MTRNR2L12 and GPNMB, which might be potential neuropathological biomarkers of a cortex chronically exposed to seizures and of balloon cells, respectively