Mechanisms of ischaemic stroke damage

Vanessa Helena Brait
Brain inflammation contributes to ischaemic and reperfusion injury, and thus worsens outcome after stroke. This thesis aimed to identify and investigate some of the inflammatory mechanisms that occur after cerebral ischaemia-reperfusion, to further enhance our understanding of them, and to potentially target them for future ischaemic stroke therapies. This study primarily used C57Bl6/J mice, as well as genetically modified mice. The model of focal cerebral ischaemia utilised was the
more » ... was the intraluminal filament-induced middle cerebral artery occlusion. Real-time PCR and Western blotting were used to examine mRNA and protein expression levels, respectively, in the brain, and immunofluorescence and immunohistochemistry were used to localise proteins and cells in the brain. T lymphocytes were isolated from the blood and spleen using Dynal negative isolation kits, and T lymphocyte-generated superoxide was measured using L-012-enhanced chemiluminescence. Chapters 3 and 4 provided the first evidence that the larger infarct volume in males versus females following cerebral ischaemia is reperfusion-dependent and may be due to greater neuro-inflammation and brain infiltration of Nox2-expressing CD3+ T lymphocytes in male mice. Moreover, this gender difference was found to be dependent on Nox2 expression. The study also demonstrated for the first time that Nox2-expressing circulating CD3+ T lymphocytes produce ~15-fold more superoxide after stroke, compared to CD3+ T lymphocytes from control mice. These findings raise the possibility that therapies to reduce CD3+ T lymphocyte infiltration and/or the production of superoxide from these cells in ischaemic stroke patients who receive recombinant t-PA, might be useful for reducing reperfusion injury. Chapter 5 confirmed and extended the above findings and demonstrated for the first time that circulating Nox2-containing CD4+ and CD8+ T lymphocytes generate substantially higher levels of superoxide after cerebral ischaemia-reperfusion compared with similar T lymphocyte subsets from con [...]
doi:10.4225/03/589299357320c fatcat:sv7cd5ng6zhmrklc3jj5ulfrii