Giustizieri Michela, Petrillo Sara, D'Amico Jessica, Torda Caterina, Quatrana Andrea, Vigevano Federico, Specchio Nicola, Piemonte Fiorella, Cherubini Enrico
European Brain Research Institute (EBRI)-Rita Levi-Montalcini Foundation, Rome, Italy.
Muscular and Neurodegenerative Diseases Laboratory, Research Area of Neurological Sciences and Rehabilitation Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Front Cell Neurosci. 2023 Jun 15;17:1213732. doi: 10.3389/fncel.2023.1213732. eCollection 2023.
Epilepsy is a neurological disorder characterized by recurrent seizures, which result from excessive, synchronous discharges of neurons in different brain areas. In about 30% of cases, epileptic discharges, which vary in their etiology and symptomatology, are difficult to treat with conventional drugs. Ferroptosis is a newly defined iron-dependent programmed cell death, characterized by excessive accumulation of lipid peroxides and reactive oxygen species. Evidence has been provided that ferroptosis is involved in epilepsy, and in particular in those forms resistant to drugs. Here, whole cell patch clamp recordings, in current and voltage clamp configurations, were performed from layer IV principal neurons in cortical slices obtained from adult mouse brain. Application of the ferroptosis inducer RAS-selective lethal 3 (RSL3) induced interictal epileptiform discharges which started at RSL3 concentrations of 2 μM and reached a plateau at 10 μM. This effect was not due to changes in active or passive membrane properties of the cells, but relied on alterations in synaptic transmission. In particular, interictal discharges were dependent on the excessive excitatory drive to layer IV principal cells, as suggested by the increase in frequency and amplitude of spontaneously occurring excitatory glutamatergic currents, possibly dependent on the reduction of inhibitory GABAergic ones. This led to an excitatory/inhibitory unbalance in cortical circuits. Interictal bursts could be prevented or reduced in frequency by the lipophilic antioxidant Vitamin E (30 μM). This study allows identifying new targets of ferroptosis-mediated epileptic discharges opening new avenues for the treatment of drug-resistant forms of epilepsy.
癫痫是一种以反复发作的癫痫发作为特征的神经系统疾病,其发作是由不同脑区神经元的过度同步放电引起的。在大约30%的病例中,病因和症状各异的癫痫放电难以用传统药物治疗。铁死亡是一种新定义的铁依赖性程序性细胞死亡,其特征是脂质过氧化物和活性氧的过度积累。已有证据表明铁死亡与癫痫有关,特别是与那些对药物耐药的癫痫形式有关。在此,采用全细胞膜片钳记录技术,在电流钳和电压钳配置下,对成年小鼠大脑皮质切片中IV层主要神经元进行记录。应用铁死亡诱导剂RAS选择性致死3(RSL3)可诱导发作间期癫痫样放电,该放电在RSL3浓度为2μM时开始,在10μM时达到平台期。这种效应不是由于细胞主动或被动膜特性的改变,而是依赖于突触传递的改变。特别是,发作间期放电依赖于对IV层主要细胞的过度兴奋性驱动,这表现为自发兴奋性谷氨酸能电流的频率和幅度增加,可能依赖于抑制性γ-氨基丁酸能电流的减少。这导致了皮质回路中兴奋/抑制失衡。亲脂性抗氧化剂维生素E(30μM)可预防发作间期爆发或降低其频率。这项研究有助于确定铁死亡介导的癫痫放电的新靶点,为治疗耐药性癫痫开辟新途径。