Neuroinflammation : identifying approaches to protect neurons from inflammation-related death

Inflammation is a common feature in neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. Microglia play a critical role in the inflammatory process by releasing pro-inflammatory factors including pro-inflammatory cytokines and reactive oxygen species. This thesis investigates a number of mechanisms that have the potential to protect neurons from inflammation and reactive oxygen species mediated death, including treatment with plant polyphenols, and expression of a potential neuroprotective gene, Lmo7. To investigate the pro-inflammatory microglia response, a range of microglial cell systems were tested; including two microglia isolation methods (CD11b magnetic beads and the shaking-off method). These methods were compared in terms of yield, morphology and NO and cytokine release. The limitations in microglial cell numbers obtained from primary tissue makes the use of cell lines an important tool for high-throughput assays. Therefore the functional properties of the macrophage cell line RAW264.7 as well as the microglia cell line C8B4 were investigated and their levels of NO release and cytokine profiles were compared with those of primary cells. Finally, the effect of the polyphenolic compounds apigenin and resveratrol on the pro-inflammatory microglia and macrophage cell response was investigated. The results from this study could not prove Lmo7 to be solely responsible for protecting neurons from hydrogen peroxide. Furthermore it was confirmed that the CD11b magnetic bead isolation technique is better suited to obtain a high yield of homogenous microglia than the shaking-off method. C8B4 cells were shown to be a suitable microglial cell line for inflammatory research. Finally, it was confirmed that both polyphenolic compounds tested were potent in preventing the pro-inflammatory activation of microglia with apigenin being slightly more potent. Therefore a multi-compound approach is proposed for the prevention of inflammation in neurodegenerative diseases