Cell-therapies that invoke pleiotropic mechanisms may facilitate functional recovery in stroke patients. We hypothesized that a cell therapy using microglia preconditioned by optimal oxygen-glucose deprivation (OGD) is a therapeutic strategy for ischemic stroke because optimal ischemia induces anti-inflammatory M2 microglia. We first delineated changes in angiogenesis and axonal outgrowth in the ischemic cortex using rats. We found that slight angiogenesis without axonal outgrowth were activated at the border area within the ischemic core from 7 to 14 days after ischemia. Next, we demonstrated that administration of primary microglia preconditioned by 18 hours of OGD at 7 days prompted functional recovery at 28 days after focal cerebral ischemia compared to control therapies by marked secretion of remodelling factors such as vascular endothelial growth factor, matrix metalloproteinase-9, and transforming growth factor-β polarized to M2 microglia in vitro/vivo. In conclusion, intravascular administration of M2 microglia preconditioned by optimal OGD may be a novel therapeutic strategy against ischemic stroke.

In the central nervous system, progranulin, a glycoprotein growth factor, plays a crucial role in maintaining physiological functions, and progranulin gene mutations cause TAR DNA-binding protein-43-positive frontotemporal lobar degeneration. Although several studies have reported that progranulin plays a protective role against ischaemic brain injury, little is known about temporal changes in the expression level, cellular localization, and glycosylation status of progranulin after acute focal cerebral ischaemia. In addition, the precise mechanisms by which progranulin exerts protective effects on ischaemic brain injury remains unknown. Furthermore, the therapeutic potential of progranulin against acute focal cerebral ischaemia, including combination treatment with tissue plasminogen activator, remains to be elucidated. In the present study, we aimed to determine temporal changes in the expression and localization of progranulin after ischaemia as well as the therapeutic effects of progranulin on ischaemic brain injury using in vitro and in vivo models. First, we demonstrated a dynamic change in progranulin expression in ischaemic Sprague-Dawley rats, including increased levels of progranulin expression in microglia within the ischaemic core, and increased levels of progranulin expression in viable neurons as well as induction of progranulin expression in endothelial cells within the ischaemic penumbra. We also demonstrated that the fully glycosylated mature secretory isoform of progranulin (∼88 kDa) decreased, whereas the glycosylated immature isoform of progranulin (58-68 kDa) markedly increased at 24 h and 72 h after reperfusion. In vitro experiments using primary cells from C57BL/6 mice revealed that the glycosylated immature isoform was secreted only from the microglia. Second, we demonstrated that progranulin could protect against acute focal cerebral ischaemia by a variety of mechanisms including attenuation of blood-brain barrier disruption, neuroinflammation suppression, and neuroprotection. We found that progranulin could regulate vascular permeability via vascular endothelial growth factor, suppress neuroinflammation after ischaemia via anti-inflammatory interleukin 10 in the microglia, and render neuroprotection in part by inhibition of cytoplasmic redistribution of TAR DNA-binding protein-43 as demonstrated in progranulin knockout mice (C57BL/6 background). Finally, we demonstrated the therapeutic potential of progranulin against acute focal cerebral ischaemia using a rat autologous thrombo-embolic model with delayed tissue plasminogen activator treatment. Intravenously administered recombinant progranulin reduced cerebral infarct and oedema, suppressed haemorrhagic transformation, and improved motor outcomes (P = 0.007, 0.038, 0.007 and 0.004, respectively). In conclusion, progranulin may be a novel therapeutic target that provides vascular protection, anti-neuroinflammation, and neuroprotection related in part to vascular endothelial growth factor, interleukin 10, and TAR DNA-binding protein-43, r...

SummaryAlthough a major function of B cells is to mediate humoral immunity by producing antigen-specific antibodies, a specific subset of B cells is important for immune suppression, which is mainly mediated by the secretion of the anti-inflammatory cytokine interleukin-10 (IL-10). However, the mechanism by which IL-10 is induced in B cells has not been fully elucidated. Here, we report that IjB NS , an inducible nuclear IjB protein, is important for Toll-like receptor (TLR)-mediated IL-10 production in B cells. Studies using IjB NS knockout mice revealed that the number of IL-10-producing B cells is reduced in IjB NS À/À spleens and that the TLR-

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Introduction: We previously demonstrated that progranulin (PGRN), a glycoprotein growth factor, may be a novel therapeutic target that provides vascular protection and anti-neuroinflammation properties related in part to vascular endothelial growth factor and interleukin 10, respectively. We also found that PGRN could provide neuroprotection in part by inhibition of cytoplasmic redistribution of TAR DNA-binding protein-43 (TDP-43), although its exact mechanism remains poorly understood. The purpose of this study is to determine the mechanism of neuroprotection by PGRN against ischemic neuronal injury. Methods: The middle cerebral artery of adult PGRN knock-out (KO) mice (C57BL/6 background) and wild-type (WT) mice was occluded for 90 minutes. Immunohistochemical analysis using an antibody against TDP-43 was performed to investigate the subcellular localization of TDP-43 after ischemia. We also performed Western blot analysis to investigate the expression levels of TDP-43 and activated caspase-3 using cerebral cortex tissues from a rat autologous thromboembolic model with delayed tissue plasminogen activator (tPA) treatment (4 hours after ischemia). Results: Twenty-four hours after reperfusion, neuronal cells showing cytoplasmic redistribution of TDP-43 were more frequently observed in PGRN KO mice than in WT mice (P<0.01). In a rat autologous thromboembolic model with delayed tPA treatment, the expression level of full-length of TDP-43 decreased 24 hours after ischemia via proteolytic degradation. However, intravenous administration of recombinant PGRN with delayed tPA treatment inhibited the decrease in the expression level of full-length TDP-43 as well as the increase in the expression level of activated caspase-3 compared with that of the control protein. Conclusion: This study demonstrated that PGRN might protect neuronal cells against focal cerebral ischemia via inhibition of proteolysis and abnormal cytoplasmic redistribution of TDP-43 by caspase-3.