The Weinstein Laboratory
The Weinstein Lab employs both in vivo and in vitro experimental models of ischemia to study microglial responses. For our in vivo studies, we couple the mouse middle cerebral artery occlusion (MCAO) stroke model with ex vivo flow cytometric isolation of microglia from cortex. In order to determine infarct volume in our stroked mice we use both MRI and standard histological methods (Fig.2).
We carry out cell targeted microarray analyses on the sorted cortical microglia (Fig.3). Using this approach we are able to compare the microglial response to IPC/ischemia in wild-type mice with that of microglia in selected knockout and transgenic lines. Correspondingly, we are able to elucidate the effects of experimental treatments on a variety of outcome parameters.
For our in vitro experimental paradigm we expose cultured primary mouse microglia to hypoxic/hypoglycemic conditions and then we monitor an array of experimental parameters. Past studies have included characterizing the cellular consequences of microglial activation by the blood coagulation proteinase thrombin -- an important factor in stroke pathophysiology. Our more recent work has implicated both Toll-like receptor-4 (TLR4) and type 1 interferon (IFN)-stimulated genes as key mediators of the microglial response to ischemia/IPC. Both TLR4 and the IFN family of cytokines are recognized as key components of the innate immune response. Ongoing projects in our laboratory are examining how disruption of the TLR4 and/or type 1 IFN signaling pathways, specifically in microglia, can affect both IPC and stroke.