scholarly journals Inhibition of Perforin-Mediated Neurotoxicity Attenuates Neurological Deficits After Ischemic Stroke

2021 ◽  
Vol 15 ◽  
Author(s):  
Yuhualei Pan ◽  
Dan Tian ◽  
Huan Wang ◽  
Yushang Zhao ◽  
Chengjie Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
Ischemic Stroke ◽  
Immune Cells ◽  
Infarct Volume ◽  
Γδ T Cells ◽  
Neurological Deficits ◽  
Wild Type ◽  
Critical Function ◽  
Ischemic Brain ◽  
Potential Strategy

Perforin-mediated cytotoxicity plays a crucial role in microbial defense, tumor surveillance, and primary autoimmune disorders. However, the contribution of the cytolytic protein perforin to ischemia-induced secondary tissue damage in the brain has not been fully investigated. Here, we examined the kinetics and subpopulations of perforin-positive cells and then evaluated the direct effects of perforin-mediated cytotoxicity on outcomes after ischemic stroke. Using flow cytometry, we showed that perforin+CD45+ immune cells could be detected at 12 h and that the percentage of these cells increased largely until on day 3 and then significantly declined on day 7. Surprisingly, the percentage of Perforin+CD45+ cells also unexpectedly increased from day 7 to day 14 after ischemic stroke in Perforin1-EGFP transgenic mice. Our results suggested that Perforin+CD45+ cells play vital roles in the ischemic brain at early and late stages and further suggested that Perforin+CD45+ cells are a heterogeneous population. Surprisingly, in addition to CD8+ T cells, NK cells, and NKT cells, central nervous system (CNS)-resident immune microglia, which are first triggered and activated within minutes after ischemic stroke in mice, also secreted perforin during ischemic brain injury. In our study, the percentage of perforin+ microglia increased from 12 h after ischemic stroke, increased largely until on day 3 after ischemic stroke, and then moderately declined from days 3 to 7. Intriguingly, the percentage of perforin+ microglia also dramatically increased from days 7 to 14 after ischemic stroke. Furthermore, compared with wild-type littermates, Perforin 1–/– mice exhibited significant increases in the cerebral infarct volume, neurological deficits, and neurogenesis and inhibition of neurotoxic astrogliosis. Interestingly, the number of CD45+CD3+ T cells was significantly decreased in Perforin 1–/– mice compared with their wild-type littermates, especially the number of γδ T cells. In addition, Perforin 1–/– mice had lower levels of IL-17 than their wild-type littermates. Our results identified a critical function of perforin-mediated neurotoxicity in the ischemic brain, suggesting that targeting perforin-mediated neurotoxicity in brain-resident microglia and invading perforin+CD45+ immune cells may be a potential strategy for the treatment of ischemic stroke.

Abstract 3856: Adoptive Transfer Of Regulatory T Cells Confers Long Term Neuroprotection Against Cerebral Ischemic Stroke

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Peiying Li ◽  
Xiaoming Hu ◽  
Yu Gan ◽  
Feng Zhang ◽  
Yanqin Gao ◽  
...  
Keyword(s):  
T Cells ◽  
Ischemic Stroke ◽  
Regulatory T Cells ◽  
Infarct Volume ◽  
The Body ◽  
Neurological Deficits ◽  
Adoptive Therapy ◽  
Ischemic Brain ◽  
Cell Based Therapy

Stroke is the leading cause of serious long-term disability in adults. Activation and mobilization of CD4+CD25+ regulatory T cells (Tregs) is an intrinsic mechanism the body uses to restrict pro-inflammatory response, one of the well-established contributing factors for secondary neuronal injury and long-term neurological deficits after stroke. The current study explores the protective effect of Tregs adoptive therapy against post-ischemic brain damage and investigated the mechanisms underlying the action of Tregs. Using a mouse model of focal transient ischemia, we found that intravenous injections of Tregs (2 x 10 6 /animal) within 24 hours (2, 6, and 24 hours) after ischemia resulted in marked reduction of brain infarct. The maximal protection occurred upon earlier Tregs transfer with 2-hour delay after MCAO, which resulted in approximately 30% reduction of infarct volume. Post-ischemic sensorimotor dysfunction significantly improved during both the acute and late recovery after MCAO in Treg-treated mice as assessed by corner test, forelimb placing and cylinder test up to 28 days after ischemic stroke. Furthermore, Tregs treatment inhibited the up-regulation of IL-6, IL-1β, IL-17 and TNF-α in the ischemic brain and mitigated the cerebral infiltration of peripheral immune cells, including neutrophil, macrophage and T cells early after MCAO. Taken together, our study demonstrates that adoptive therapy with Tregs is a novel and potent cell-based therapy targeting post-stroke inflammatory dysregulation.

EDA-Containing Fibronectin Aggravates Ischemic Brain Injury In Mice

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 330-330
Author(s):  
Anil Chauhan ◽  
Mohammad M Khan ◽  
Chintan Gandhi ◽  
Neelam Chauhan ◽  
Asgar Zaheer ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Experimental Model ◽  
Vascular Injury ◽  
Laser Doppler Flowmetry ◽  
Infarct Volume ◽  
Neurological Deficits ◽  
Ischemic Brain Injury ◽  
Doppler Flowmetry ◽  
Ischemic Brain

Abstract Abstract 330 Background: Fibronectin (FN) is a dimeric glycoprotein that plays an important role in several cellular processes, such as embryogenesis, malignancy, hemostasis, wound healing and maintenance of tissue integrity. FN is a ligand for many members of the integrin family (e.g. αIIbβ3, α5β1, α4β1, α9β1, αvβ3 and αvβ5) and also binds to thrombosis-related proteins including heparin, collagen and fibrin. FN generates protein diversity as a consequence of alternative processing of a single primary transcript. Two forms of FN exist; soluble plasma FN (pFN), which lacks the alternatively-spliced Extra Domain A (EDA); and insoluble cellular FN (cFN), which contains EDA. FN containing EDA (EDA+FN) is normally absent in plasma of human and mouse but EDA+FN has been found in patients with vascular injury secondary to vasculitis, sepsis, acute major trauma or ischemic stroke. We tested the hypothesis that elevated levels of plasma EDA+FN increase brain injury in an experimental model of ischemic stroke in mice. Model and Method: We used two genetically modified mouse strains: EDA+/+ mice contain optimized spliced sites at both splicing junctions of the EDA exon and constitutively express only EDA+FN, whereas EDA-/- mice contain an EDA-null allele of the EDA exon and express only FN lacking EDA. Control EDAwt/wt mice contain the wild-type FN allele. Transient focal cerebral ischemia was induced by 60 minutes of occlusion of the right middle cerebral artery with a 7.0 siliconized filament in male mice (8-10 weeks in age). Mice were anesthetized with 1–1.5% isoflurane mixed with medical air. Body temperature was maintained at 37°C ± 1.0 using a heating pad. Laser Doppler flowmetry was used to confirm induction of ischemia and reperfusion. At 23 hours after MCAO, mice were evaluated for neurological deficits as a functional outcome and were sacrificed for quantification of infarct volume. For morphometric measurement eight 1 mm coronal sections were stained with 2% triphenyl-2, 3, 4-tetrazolium-chloride (TTC). Sections were digitalized and infarct areas were measured blindly using NIS elements. Result: In EDA+/+ mice the percentage of infarct volume (mean ± SEM: 37.25 ± 4.11, n= 12,) in the ipsilateral (ischemic) hemisphere was increased by approximately two-fold compared to EDA wt/wt mice (mean ± SEM: 22.33 ± 3.39, n=11; P< 0.05, ANOVA) or EDA-/- mice (mean ± SEM: 21.72 ± 2.94, n=9). Regional cerebral blood flow during ischemia was not different among groups as assessed by laser Doppler flowmetry. The percentage increase in infarct volume in the EDA+/+ mice correlated well with severe neurological deficits (motor-deficit assessed by a four-point neurological score scale) compared to EDA wt/wt or EDA-/- mice. Because both thrombosis and inflammation contributes to brain injury during ischemic stroke, we investigated the time to form an occlusive thrombus in ferric-chloride carotid artery injury model by intravital microscopy. EDA+/+ mice demonstrated significantly faster time to occlusion (mean ± SEM: 12.35 ± 1.51 n=12,) compared to EDAwt/wt (Mean ± SEM: 17.27 ± 1.72 min, n=13, P<0.05, ANOVA) or EDA-/- (Mean ± SEM: 15.61 ± 1.76, n=11) mice. Additionally, the inflammatory response in the ischemic region was increased by two fold in EDA+/+ mice compared to EDA wt/wt and EDA-/- mice as sensed by myeloperoxidase activity and immunohistochemical analysis of neutrophils. Conclusion: EDA-containing FN is pro-thrombotic and pro-inflammatory, and aggravates ischemic brain injury in an experimental model of stroke in mice. The presence of EDA+FN in plasma may be a risk factor for vascular injury secondary to ischemic stroke. Disclosures: No relevant conflicts of interest to declare.

Abstract WP96: The Role of T-Lymphocytes in Neuroregeneration After Cerebral Ischemia

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Kai Diederich ◽  
Antje Schmidt ◽  
Jan-Kolja Strecker ◽  
Wolf-Rüdiger Schäbitz ◽  
Jens Minnerup
Keyword(s):  
T Cells ◽  
Ischemic Stroke ◽  
Adoptive Transfer ◽  
Critical Role ◽  
Chronic Phase ◽  
Cognitive Testing ◽  
Neurological Deficits ◽  
Ischemic Brain ◽  
Immunodeficient Mice

Introduction: Inflammation plays a critical role in the pathogenesis of ischemic stroke. The CNS responds to ischemic injury with an inflammatory process, characterized by an infiltration of inflammatory cells. Particularly T cells exhibit a great impact on early stroke outcome as recent studies showed that ablation of these cells decrease infarct size and improve neurological deficits in the acute phase after stroke. However, the role of T cells in the sub-acute and chronic phase after stroke is unknown. T cells are essential for effective neurogenesis and angiogenesis, mechanisms that are integral for successful regeneration after stroke. We assessed the hypothesis that T cells influence cellular mechanisms of post-ischemic neuroregeneration and consequently affect functional and structural recovery. Methods: 24 wild type (wt) and 11 RAG1 -/- mice were subjected to photothrombotic ischemia, a subset of 12 wt and 6 RAG1 -/- animals underwent training in motorized running wheels starting at day 3 following ischemia until the end of the experiment on day 28. Sensorimotor and cognitive testing was applied to quantify the recovery process. To label newly generated neurons, 5-Chloro-2′-deoxyuridine (CldU) and iododeoxyuridine (IdU) were administered at days 1 and 2 (CldU) and once weekly until day 28 (IdU) after ischemia. In a subsequent experiment, 17 RAG1 -/- mice were subjected to photothrombotic ischemia and underwent training, a subset of 10 animals received an adoptive transfer of T cells. Functional testing and cellular labeling were carried out in analogy to the first experiment. Results: Training improved recovery from sensorimotor and cognitive deficits following cortical ischemia in wt animals and increased the generation of new neurons in the ischemic brain. Rehabilitative training did not induce functional recovery in RAG1 -/- animals and had no effect on the generation of neurons. Adoptive transfer of T cells into the immunodeficient mice restored the ability for regeneration. Conclusion: T cells play an essential role in the functional and structural regeneration following ischemic brain injury. These results provide new clues on the complex mechanism by which immune cells impact different stages of the pathogenesis of ischemic stroke.

scholarly journals ERK1/2 Activity Is Critical for the Outcome of Ischemic Stroke

2022 ◽  
Vol 23 (2) ◽  
pp. 706
Author(s):  
Constanze Schanbacher ◽  
Michael Bieber ◽  
Yvonne Reinders ◽  
Deya Cherpokova ◽  
Christina Teichert ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Kinase Inhibitor ◽  
Infarct Volume ◽  
Neurological Deficits ◽  
Wild Type ◽  
Tight Control ◽  
Raf Kinase ◽  
Raf Kinase Inhibitor Protein ◽  
Extracellular Signal ◽  
Stimulation Of

Ischemic disorders are the leading cause of death worldwide. The extracellular signal-regulated kinases 1 and 2 (ERK1/2) are thought to affect the outcome of ischemic stroke. However, it is under debate whether activation or inhibition of ERK1/2 is beneficial. In this study, we report that the ubiquitous overexpression of wild-type ERK2 in mice (ERK2wt) is detrimental after transient occlusion of the middle cerebral artery (tMCAO), as it led to a massive increase in infarct volume and neurological deficits by increasing blood–brain barrier (BBB) leakiness, inflammation, and the number of apoptotic neurons. To compare ERK1/2 activation and inhibition side-by-side, we also used mice with ubiquitous overexpression of the Raf-kinase inhibitor protein (RKIPwt) and its phosphorylation-deficient mutant RKIPS153A, known inhibitors of the ERK1/2 signaling cascade. RKIPwt and RKIPS153A attenuated ischemia-induced damages, in particular via anti-inflammatory signaling. Taken together, our data suggest that stimulation of the Raf/MEK/ERK1/2-cascade is severely detrimental and its inhibition is rather protective. Thus, a tight control of the ERK1/2 signaling is essential for the outcome in response to ischemic stroke.

Abstract W P199: Deficiency of Glia Maturation Factor Abrogates Brain Injury and Inflammation in a Murine Model of Stroke

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Mohammad M Khan ◽  
Asgar Zaheer
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Proinflammatory Cytokines ◽  
Inflammatory Responses ◽  
Infarct Volume ◽  
Neurological Deficits ◽  
Glia Maturation Factor ◽  
Western Blots ◽  
Ischemic Brain ◽  
Maturation Factor

Background and purpose: Glia maturation factor (GMF), a brain specific protein, discovered and characterized in our laboratory, induces expression of proinflammatory cytokines/ chemokines in the central nervous system (CNS). Recently, it has been demonstrated that deficiency of GMF mitigates neuronal damage in tissue culture cell and animal models of neurodegeneration. Since, GMF expression in brain enhances inflammation; we tested the hypothesis that deficiency of GMF abrogates the inflammatory responses in experimental model of ischemic stroke. Methods: Transient focal cerebral ischemia was induced by 1 hour of occlusion of the right middle cerebral artery (MCAO) with a 7.0 monofilament in GMF-containing wild type (Wt) and GMF-deficient (GMF-KO) mice. Mice were anesthetized with 1-1.5% isoflurane mixed with medical oxygen. Body temperature was maintained at 37°C ± 1.0 using a heating pad. At 23 hours after ischemia/reperfusion, mice were tested for neurological scores and were sacrificed for the infarct volume and estimation of inflammatory responses. Immunohistochemistry and western blots were used to analyze the expression and activation of glial cells, and levels of NF-κB in ischemic brain hemisphere. Results: We found that levels of GMF significantly increased in MCAO mice compared to saline treated control mice. Next we found that GMF-KO mice exhibited significantly decreased infarct volume, and reduced neurological deficits compared to Wt mice. The decrease in infarct volume and neurological deficits in GMF-KO mice were correlated with a less activation of glia cells, downregulation of NF-κB and suppression of proinflammatory cytokines/chemokine in the ischemic region. Conclusions: In conclusion, present study provides the first evidence that deficiency of GMF reduces brain injury and inflammation after ischemic stroke and suggests that the effective suppression of endogenous GMF-function will prove to be an effective and selective strategy to slow deleterious inflammatory processes in ischemic brain injury. Keywords: Glia maturation factor; Ischemic stroke; Inflammation; Nuclear factor-κB; Cytokines

scholarly journals Double-negative T cells remarkably promote neuroinflammation after ischemic stroke

2019 ◽  
Vol 116 (12) ◽  
pp. 5558-5563 ◽  
Author(s):  
Hailan Meng ◽  
Haoran Zhao ◽  
Xiang Cao ◽  
Junwei Hao ◽  
He Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
Ischemic Stroke ◽  
Inflammatory Responses ◽  
Dependent Manner ◽  
Double Negative ◽  
Critical Function ◽  
Ischemic Brain ◽  
Tnf Α ◽  
The Central Nervous System ◽  
Double Negative T Cells

CD3+CD4−CD8−T cells (double-negative T cells; DNTs) have diverse functions in peripheral immune-related diseases by regulating immunological and inflammatory homeostasis. However, the functions of DNTs in the central nervous system remain unknown. Here, we found that the levels of DNTs were dramatically increased in both the brain and peripheral blood of stroke patients and in a mouse model in a time-dependent manner. The infiltrating DNTs enhanced cerebral immune and inflammatory responses and exacerbated ischemic brain injury by modulating the FasL/PTPN2/TNF-α signaling pathway. Blockade of this pathway limited DNT-mediated neuroinflammation and improved the outcomes of stroke. Our results identified a critical function of DNTs in the ischemic brain, suggesting that this unique population serves as an attractive target for the treatment of ischemic stroke.

scholarly journals Loss of Gucy1a3 Causes Poor Post-Stroke Recovery by Reducing Angiogenesis Via the HIF-1α/VEGFA Signaling Pathway in Mice

2022 ◽  
Author(s):  
Man Luo ◽  
Dongcan Mo ◽  
LiuYu Liu ◽  
Jianli Li ◽  
Jing Lin ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Signaling Pathway ◽  
Infarct Volume ◽  
Hypoxia Inducible Factor ◽  
Soluble Guanylyl Cyclase ◽  
Stroke Recovery ◽  
Neurological Deficits ◽  
Wild Type ◽  
Expression Levels ◽  
Post Stroke

Abstract Ischemic stroke is a common and debilitating disease that can cause permanent neurological damage. Gucy1a3, which encodes the α1 subunit of soluble guanylyl cyclase, has been reported to be associated with functional recovery after ischemic stroke. However, the mechanism is still not well understood. In the present study, we investigated the effects of Gucy1a3 on (i) post-stroke recovery; (ii) vascular endothelial growth factor A (VEGFA) and hypoxia inducible factor 1 alpha (HIF-1α) expression; and (iii) angiogenesis after ischemic stroke. A permanent middle cerebral artery occlusion (pMCAO) model was established using wild-type and Gucy1a3 knockout C57BL/6J male mice. Neurological deficits, infarct volume, microvascular density, and VEGFA and HIF-1α expression levels of mice were evaluated. Our results suggest that loss of Gucy1a3 increased the infarct volume and aggravated neurological deficits after pMCAO. In addition, the Gucy1a3 knockout brains exhibited significantly lower microvessel densities and VEGFA and HIF-1α expression levels than the wild-type brains at 96 hours post-pMCAO. The study shows that the expression of GUCY1A3 after ischemic stroke may play a substantial role in neurological function recovery and is related to angiogenesis in the peri-infarct region. The beneficial effects of GUCY1A3 might be mediated through the HIF-1α/VEGFA signaling pathway.

scholarly journals Distinct contributions of CD4+ T cell subsets in hepatic ischemia/reperfusion injury

2009 ◽  
Vol 296 (5) ◽  
pp. G1054-G1059 ◽  
Author(s):  
Satoshi Kuboki ◽  
Nozomu Sakai ◽  
Johannes Tschöp ◽  
Michael J. Edwards ◽  
Alex B. Lentsch ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Ischemia Reperfusion ◽  
Γδ T Cells ◽  
Nkt Cells ◽  
T Cell Subsets ◽  
Wild Type ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion

Helper T cells are known to mediate hepatic ischemia/reperfusion (I/R) injury. However, the precise mechanisms and subsets of CD4+ T cells that contribute to this injury are still controversial. Therefore, we sought to determine the contributions of different CD4+ T cell subsets during hepatic I/R injury. Wild-type, OT-II, or T cell receptor (TCR)-δ-deficient mice were subjected to 90 min of partial hepatic ischemia followed by 8 h of reperfusion. Additionally, wild-type mice were pretreated with anti-CD1d, -NK1.1, or -IL-2R-α antibodies before I/R injury. OT-II mice had diminished liver injury compared with wild-type mice, implicating that antigen-dependent activation of CD4+ T cells through TCRs is involved in hepatic I/R injury. TCR-δ knockout mice had decreased hepatic neutrophil accumulation, suggesting that γδ T cells regulate neutrophil recruitment. We found that natural killer T (NKT) cells, but not NK cells, contribute to hepatic I/R injury via CD1d-dependent activation of their TCRs, as depletion of NKT cells by anti-CD1d antibody or depletion of both NKT cells and NK cells by anti-NK1.1 attenuated liver injury. Although regulatory T cells (Treg) are known to suppress T cell-dependent inflammation, depletion of Treg cells had little effect on hepatic I/R injury. The data suggest that antigen-dependent activation of CD4+ T cells contributes to hepatic I/R injury. Among the subsets of CD4+ T cells, it appears that γδ T cells contribute to neutrophil recruitment and that NKT cells directly injure the liver. In contrast, NK cells and Treg have little effects on hepatic I/R injury.

scholarly journals γδ T Cells and NK Cells – Distinct Pathogenic Roles as Innate-Like Immune Cells in CNS Autoimmunity

2015 ◽  
Vol 6 ◽  
Author(s):  
Sarah C. Edwards ◽  
Aoife M. McGinley ◽  
Niamh C. McGuinness ◽  
Kingston H. G. Mills
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Immune Cells ◽  
Γδ T Cells ◽  
Cns Autoimmunity
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