Dottorato in NEUROSCIENZE CLINICO-SPERIMENTALI E PSICHIATRIA

Titolo della tesi: Cytokines modulation of GABAARs function in neurodevelopmental disorders

ABSTRACT Glioneuronal tumours, including gangliogliomas (GG) represent developmental low-grade brain tumours and are a well-recognized cause of intractable focal epilepsy in children and young adults. Previous studies have provided evidence in GG, similarly to epileptogenic focal malformations (i.e., cortical tubers in tuberous sclerosis complex, TSC) of a sustained inflammatory response with activation of both the innate and adaptive immune response and involvement of different pathways activated by the proinflammatory cytokines such as interleukin-1β (IL-1β). The importance of these pro-inflammatory stimuli is clear and well described. On the other hand, the role of anti-inflammatory mediators (i.e., IL-10) is not so defined and potentially exploitable for future therapeutic developments. Here, we used a multidisciplinary approach involving bioinformatics analysis, electrophysiology and immunohistochemistry studies to define a potential effect of IL-10 on GABAergic neurotransmission in the aforementioned diseases. Indeed, using membrane microtransplantation from human GG and TSC samples in Xenopus oocytes, we performed voltage-clamp recordings of GABA-evoked currents due to the activation of “transplanted” GABAA receptors (GABAARs). Using transcriptomics, we described an upregulation of the mRNAs linked to IL-10 axis which was present in GG and TSC, but was more prominent in these latter. In oocytes microtransplanted with human brain tissues, we found a statistically relevant GABA current increase induced by IL-10 incubation in GG and a similar tendency in TSC. This effect was time and dose-dependent, washable and prevented by blocking the IL-10 down-stream signaling. In addition, double-labeling immunohistochemistry showed the presence of IL-10 receptor both in neuronal and astroglial cells. Interestingly, on the same tissues the pre-incubation with IL-1β was able to abolish the IL-10 induced GABA current modulation.