Activation of the pro-resolving receptor Fpr2 attenuates inflammatory microglial activation

Poster number: P-T099 Theme: Neurodegenerative disorders & ageing Activation of the pro-resolving receptor Fpr2 reverses inflammatory microglial activation Authors: Edward S Wickstead - Life Science & Technology University of Westminster/Queen Mary University of London Inflammation is a major contributor to many neurodegenerative disease (Heneka et al. 2015). Microglia, as the resident immune cells of the brain and spinal cord, provide the first line of immunological defence, but can become deleterious when chronically activated, triggering extensive neuronal damage (Cunningham, 2013). Dampening or even reversing this activation may provide neuronal protection against chronic inflammatory damage. The aim of this study was to determine whether lipopolysaccharide (LPS)-induced inflammation could be abrogated through activation of the receptor Fpr2, known to play an important role in peripheral inflammatory resolution. Immortalised murine microglia (BV2 cell line) were stimulated with LPS (50ng/ml) for 1 hour prior to the treatment with one of two Fpr2 ligands, either Cpd43 or Quin-C1 (both 100nM), and production of nitric oxide (NO), tumour necrosis factor alpha (TNFα) and interleukin-10 (IL-10) were monitored after 24h and 48h. Treatment with either Fpr2 ligand significantly suppressed LPS-induced production of NO or TNFα after both 24h and 48h exposure, moreover Fpr2 ligand treatment significantly enhanced production of IL-10 48h post-LPS treatment. As we have previously shown Fpr2 to be coupled to a number of intracellular signaling pathways (Cooray et al. 2013), we investigated potential signaling responses. Western blot analysis revealed no activation of ERK1/2, but identified a rapid and potent activation of p38 MAP kinase in BV2 microglia following stimulation with Fpr2 ligands. Together, these data indicate the possibility of exploiting immunomodulatory strategies for the treatment of neurological diseases, and highlight in particular the important potential of resolution mechanisms as novel therapeutic targets in neuroinflammation. References Cooray SN et al. (2013). Proc Natl Acad Sci U S A 110: 18232-7. Cunningham C (2013). Glia 61: 71-90. Heneka MT et al. (2015). Lancet Neurol 14: 388-40

MECHANISMS OF MEMORY CONSOLIDATION

Extensive research has shown that sleep supports memory. Newer work suggests that wakefulness can also benefit retention of new information. However, the exact mechanisms which govern memory consolidation in sleep and wake are largely unknown. The implementation of new technologies, which draw on these natural memory processes, allows some insight into their characteristics. This work aims at elucidating some aspects of memory consolidation processes in the realm of sleep and wake. Firstly, we train novel non-words, a material previously indicated to benefit from sleep-associated consolidation, with explicit and implicit methods to determine whether the implicit learning (via the Hebb repetition task) would facilitate lexical integration independently of sleep. The results reveal that lexical integration of novel words is contingent on a good level of explicit training, followed by a consolidation delay with sleep. We speculate that sleep-associated consolidation may be mediated by the degree of overlap between new and already known material. To further capitalise on these findings, we test whether applying non-verbal cues during sleep can improve learning of novel words and their integration within the lexicon using Targeted Memory Reactivation (TMR) paradigm. Our results indicate that reactivating novel lexical representations in sleep improves their consolidation and facilitates their recall. However, the lack of lexical integration observed suggests the need for future research. Finally, based on recent evidence that quiet wakeful rest can result in comparable memory increases to sleep, we explore the consolidation during awake state using transcranial direct current stimulation (tDCS). We found that applying tDCS to the right occipital-parietal site enhances memory for a list of words as compared to no stimulation. The findings imply that memory consolidation during quiet wakefulness can be manipulated externally, which may direct future research. Nevertheless, the exact neuro-correlates of memory consolidation in quiet wake are yet to be fully investigated

Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers