Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
Claudio Munari Epilepsy Surgery Center, Niguarda Hospital, Milan, Italy.
Epilepsia. 2020 Jun;61(6):1240-1252. doi: 10.1111/epi.16549. Epub 2020 May 28.
Activity-dependent changes have been reported in animal models and in human epileptic specimens and could potentially be used as tissue biomarkers to evaluate the propensity of a tissue to generate seizure activity. In this context, cAMP-response element binding protein (CREB) activation was specifically reported in human epileptic foci and related mainly to interictal spike activity. To get further insights into CREB activation in human epilepsy, we analyzed pCREB expression on brain tissue samples from patients who underwent surgery for drug-resistant focal epilepsy, correlating this expression with intracranial stereo-electroencephalography (SEEG) recording in a subgroup.
Neocortical specimens from patients with neuropathological diagnosis of no lesion (cryptogenic), malformations of cortical development,mainly type II focal cortical dysplasia (FCD), and hippocampi with and without hippocampal sclerosis have been analyzed by immunohistochemistry. Peritumoral cortex from non-epileptic patients and autoptic samples were used as controls, whereas rat brains were used to test possible loss of pCREB antigenicity due to fixation procedures and postmortem delay.
pCREB was consistently expressed in layer II neuronal nuclei in regions with normal cortical lamination both in epileptic and non-epileptic surgical tissues. In patients with SEEG recordings, this anatomical pattern was unrelated to the presence of interictal spike activity. Conversely, in the core of type II FCD, as well as in other developmental malformations, pCREB was scattered without any laminar specificity. Furthermore, quantitative data did not reveal significant differences between epileptic and non-epileptic tissues, except for an increased immunoreactivity in the core of type IIB FCD lesion related mainly to reactive glial and balloon cells.
The present data argue against the reliability of pCREB immunohistochemistry as a marker of epileptic focus but underscores its layer-related expression, suggesting a potential application in the study of malformations of cortical development, a wide range of diseases arising from perturbations of normal brain development.
在动物模型和人类癫痫标本中已经报道了与活动相关的变化，并且这些变化可能被用作评估组织产生癫痫活动倾向的组织生物标志物。在这种情况下，cAMP 反应元件结合蛋白 (CREB) 的激活在人类癫痫灶中被特别报道，主要与发作间期棘波活动有关。为了更深入地了解人类癫痫中的 CREB 激活，我们分析了接受药物难治性局灶性癫痫手术的患者脑组织样本中的 pCREB 表达，并在亚组中对其与颅内立体脑电图 (SEEG) 记录进行了相关性分析。
通过免疫组织化学分析了具有无病变（隐源性）、皮质发育畸形、主要为 II 型局灶性皮质发育不良 (FCD) 的神经病理学诊断的患者的新皮质标本，以及伴有或不伴有海马硬化的海马标本。非癫痫患者的瘤周皮质和尸检样本被用作对照，而大鼠脑被用于测试由于固定程序和死后延迟可能导致的 pCREB 抗原性丧失。
pCREB 在具有正常皮质层的癫痫和非癫痫手术组织的区域中一致地表达在 II 层神经元核中。在具有 SEEG 记录的患者中，这种解剖模式与发作间期棘波活动的存在无关。相反，在 II 型 FCD 的核心以及其他发育性畸形中，pCREB 没有任何分层特异性地分散存在。此外，除了与主要是反应性神经胶质和气球细胞相关的 IIB 型 FCD 病变核心中增加的免疫反应性之外，定量数据未显示癫痫和非癫痫组织之间存在显著差异。
目前的数据表明，pCREB 免疫组织化学不能作为癫痫灶的可靠标志物，但强调了其与层相关的表达，这表明其在皮质发育畸形研究中的潜在应用，皮质发育畸形是一类广泛的疾病，源于正常大脑发育的干扰。
