PROFILING THE MICROGLIAL LNCRNA RESPONSE TO INFLAMMATORY STIMULI USING IN VITRO AND IN VIVO APPROACHES

Microglial-mediated inflammation plays a significant role in many neurological diseases including temporal lobe epilepsy. The mechanisms which provoke the initial but persisting inflammatory responses remain unclear. Long non-coding RNAs (lncRNAs) are functional RNA molecules, greater than 200 nucleotides in length which elicit a wide variety of functions in cells including regulation of transcriptional and translational processes. They have emerged as key regulators of the neuroinflammatory process although they remain almost completely unexplored in TLE. Recently we identified persistent dysregulation of lncRNAs both during epileptogenesis and in chronic epilepsy in a pre-clinical model of the disease. This work aims to further investigate whether the dysregulation of lncRNAs seen in TLE are prominent in microglia and eventually, whether they are involved in regulating persistent microglial dysfunction in epilepsy. Initially BV2 cells were stimulated with LPS to provoke an inflammatory response. To model TLE we use the intra-amygdala kainic acid model (IAKA). Microglial morphological analysis was performed on hippocampal sections from epileptogenic and epileptic mice using IBA1 immunostaining. lncRNAs were profiled using deep RNA-sequencing analysis. IAKA provokes a temporal restructuring of microglia. Inflammatory stimuli lead to profound reorganisation of the lncRNA profile in microglia. We see significant dysregulation of inflammation-related lncRNAs such as RelB, NEAT1, and IRAK1, involved in the regulation of NF-K𝛽 signalling, nuclear paraspeckles and transcription, and TLR and IL-1R signalling pathways, respectively. Elucidating microglia-associated lncRNA responses to inflammation may provide insight into novel molecular mechanisms underlying epilepsy and inform future therapeutic or biomarker development strategies.