A semiautomated method for measuring brain infarct volume

Bone marrow mesenchymal stem cells induce M2 microglia polarization through PDGF-AA/MANF signaling

BACKGROUND

Bone marrow mesenchymal stem cells (BMSCs) are capable of shifting the microglia/macrophages phenotype from M1 to M2, contributing to BMSCs-induced brain repair. However, the regulatory mechanism of BMSCs on microglia/macrophages after ischemic stroke is unclear. Recent evidence suggests that mesencephalic astrocyte–derived neurotrophic factor (MANF) and platelet-derived growth factor-AA (PDGF-AA)/MANF signaling regulate M1/M2 macrophage polarization.

AIM

To investigate whether and how MANF or PDGF-AA/MANF signaling influences BMSCs-mediated M2 polarization.

METHODS

We identified the secretion of MANF by BMSCs and developed transgenic BMSCs using a targeting small interfering RNA for knockdown of MANF expression. Using a rat middle cerebral artery occlusion (MCAO) model transplanted by BMSCs and BMSCs–microglia Transwell coculture system, the effect of BMSCs-induced downregulation of MANF expression on the phenotype of microglia/macrophages was tested by Western blot, quantitative reverse transcription-polymerase chain reaction, and immunofluorescence. Additionally, microglia were transfected with mimics of miR-30a*, which influenced expression of X-box binding protein (XBP) 1, a key transcription factor that synergized with activating transcription factor 6 (ATF6) to govern MANF expression. We examined the levels of miR-30a*, ATF6, XBP1, and MANF after PDGF-AA treatment in the activated microglia.

RESULTS

Inhibition of MANF attenuated BMSCs-induced functional recovery and decreased M2 marker production, but increased M1 marker expression in vivo or in vitro. Furthermore, PDGF-AA treatment decreased miR-30a* expression, had no influence on the levels of ATF6, but enhanced expression of both XBP1 and MANF.

CONCLUSION

BMSCs-mediated MANF paracrine signaling, in particular the PDGF-AA/miR-30a*/XBP1/MANF pathway, synergistically mediates BMSCs-induced M2 polarization.

Improved collateral flow and reduced damage after remote ischemic perconditioning during distal middle cerebral artery occlusion in aged rats

Circulation through cerebral collaterals can maintain tissue viability until reperfusion is achieved. However, collateral circulation is time limited, and failure of collaterals is accelerated in the aged. Remote ischemic perconditioning (RIPerC), which involves inducing a series of repetitive, transient peripheral cycles of ischemia and reperfusion at a site remote to the brain during cerebral ischemia, may be neuroprotective and can prevent collateral failure in young adult rats. Here, we demonstrate the efficacy of RIPerC to improve blood flow through collaterals in aged (16-18 months of age) Sprague Dawley rats during a distal middle cerebral artery occlusion. Laser speckle contrast imaging and two-photon laser scanning microscopy were used to directly measure flow through collateral connections to ischemic tissue. Consistent with studies in young adult rats, RIPerC enhanced collateral flow by preventing the stroke-induced narrowing of pial arterioles during ischemia. This improved flow was associated with reduced early ischemic damage in RIPerC treated aged rats relative to controls. Thus, RIPerC is an easily administered, non-invasive neuroprotective strategy that can improve penumbral blood flow via collaterals. Enhanced collateral flow supports further investigation as an adjuvant therapy to recanalization therapy and a protective treatment to maintain tissue viability prior to reperfusion.

Sex differences in T cell immune responses, gut permeability and outcome after ischemic stroke in aged mice

INTRODUCTION

Stroke is a disease that presents with well-known sex differences. While women account for more stroke deaths, recent data show that after adjusting for age and pre-stroke functional status, mortality is higher in men. Immune responses are key determinants of stroke outcome and may differ by sex. This study examined sex differences in central and peripheral T cell immune responses, systemic effects on gut permeability and microbiota diversity and behavioral outcomes after stroke in aged mice. We hypothesized that there are sex differences in the immune response to stroke in aged animals.

METHODS

C57BL/6CR mice (20-22 months) were subjected to 60 min middle cerebral artery occlusion, or sham surgery. T cells were quantified in brain and blood at 3, 7 and 15 days (d) post-stroke by flow cytometry. Peripheral effects on gut permeability and microbiota diversity, as well as neurological function were assessed up to 14 d, and at 21 d (cognitive function) post-stroke. Brain glial fibrillary acidic protein (GFAP) expression was evaluated at 42 d post-stroke.

RESULTS AND DISCUSSION

Mortality (50% vs 14%, p < 0.05) and hemorrhagic transformation (44% vs 0%) were significantly higher in males than in females. No difference in infarct size at 3d were observed. Peripherally, stroke induced greater gut permeability of FITC-dextran in males at d3 (p < 0.05), and non-reversible alterations in microbiota diversity in males. Following the sub-acute phase, both sexes demonstrated a time-dependent increase of CD4⁺ and CD8⁺ T cells in the brain, with significantly higher levels of CD8⁺ T cells and Regulatory T cells in males at d15 (p < 0.01). Aged males demonstrated greater neurological deficits up to d5 and impaired sensorimotor function up to d15 when assessed by the corner asymmetry test (p < 0.001 and p < 0.01, respectively). A trend in greater cognitive decline was observed at d21 in males. Increased GFAP expression in the ischemic hemisphere, indicating astroglial activation and gliosis, was demonstrated in both males and females 42d post-stroke. Our findings indicate that despite a similar initial ischemic brain injury, aged male mice experience greater peripheral effects on the gut and ongoing central neuroinflammation past the sub-acute phase after stroke.

Transcriptome Analysis of Skeletal Muscle Reveals Altered Proteolytic and Neuromuscular Junction Associated Gene Expressions in a Mouse Model of Cerebral Ischemic Stroke

Stroke is a leading cause of mortality and long-term disability in patients worldwide. Skeletal muscle is the primary systemic target organ of stroke that induces muscle wasting and weakness, which predominantly contribute to functional disability in stroke patients. Currently, no pharmacological drug is available to treat post-stroke muscle morbidities as the mechanisms underlying post-stroke muscle wasting remain poorly understood. To understand the stroke-mediated molecular changes occurring at the transcriptional level in skeletal muscle, the gene expression profiles and enrichment pathways were explored in a mouse model of cerebral ischemic stroke via high-throughput RNA sequencing and extensive bioinformatic analyses. RNA-seq revealed that the elevated muscle atrophy observed in response to stroke was associated with the altered expression of genes involved in proteolysis, cell cycle, extracellular matrix remodeling, and the neuromuscular junction (NMJ). These data suggest that stroke primarily targets muscle protein degradation and NMJ pathway proteins to induce muscle atrophy. Collectively, we for the first time have found a novel genome-wide transcriptome signature of post-stroke skeletal muscle in mice. Our study will provide critical information to further elucidate specific gene(s) and pathway(s) that can be targeted to mitigate accountable for post-stroke muscle atrophy and related weakness.

LRRC8A-dependent volume-regulated anion channels contribute to ischemia-induced brain injury and glutamatergic input to hippocampal neurons

Volume-regulated anion channels (VRACs) are critically involved in regulating cell volume, and leucine-rich repeat-containing protein 8A (LRRC8A, SWELL1) is an obligatory subunit of VRACs. Cell swelling occurs early after brain ischemia, but it is unclear whether neuronal LRRC8a contributes to ischemia-induced glutamate release and brain injury. We found that Lrrc8a conditional knockout (Lrrc8a-cKO) mice produced by crossing Nestin^Cre+/- with Lrrc8a^flox+/+ mice died 7-8 weeks of age, indicating an essential role of neuronal LRRC8A for survival. Middle cerebral artery occlusion (MCAO) caused an early increase in LRRC8A protein levels in the hippocampus in wild-type (WT) mice. Whole-cell patch-clamp recording in brain slices revealed that oxygen-glucose deprivation significantly increased the amplitude of VRAC currents in hippocampal CA1 neurons in WT but not in Lrrc8a-cKO mice. Hypotonicity increased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) in hippocampal CA1 neurons in WT mice, and this was abolished by DCPIB, a VRAC blocker. But in Lrrc8a-cKO mice, hypotonic solution had no effect on the frequency of sEPSCs in these neurons. Furthermore, the brain infarct volume and neurological severity score induced by MCAO were significantly lower in Lrrc8a-cKO mice than in WT mice. In addition, MCAO-induced increases in cleaved caspase-3 and calpain activity, two biochemical markers of neuronal apoptosis and death, in brain tissues were significantly attenuated in Lrrc8a-cKO mice compared with WT mice. These new findings indicate that cerebral ischemia increases neuronal LRRC8A-dependent VRAC activity and that VRACs contribute to increased glutamatergic input to hippocampal neurons and brain injury caused by ischemic stroke.

The circadian nuclear receptor RORα negatively regulates cerebral ischemia-reperfusion injury and mediates the neuroprotective effects of melatonin

Disruptions of the circadian rhythm and reduced circulating levels of the circadian hormone melatonin predispose to ischemic stroke. Although the nuclear receptor RORα is considered as a circadian rhythm regulator and a mediator of certain melatonin effects, its potential role in cerebral ischemia-reperfusion (CI/R) injury and in the neuroprotective effects of melatonin remain undefined. Here, we observed that CI/R injury in RORα-deficient mice was associated with greater cerebral infarct size, brain edema, and cerebral apoptosis compared with wild-type model. In contrast, transgenic mice with brain-specific overexpression of RORα versus non-transgenic controls exerted significantly reduced infarct volume, brain edema and apoptotic response induced by CI/R. Mechanistically, RORα deficiency was found to exacerbate apoptosis pathways mediated by endoplasmic-reticulum stress and mitochondria and aggravate oxidative/nitrative stress after CI/R. Further studies revealed that RORα deficiency intensified the activation of nuclear factor-κB signaling induced by CI/R. Given the emerging evidence of RORα as an essential melatonin activity mediator, we further investigated the RORα roles in melatonin-exerted neuroprotection against acute ischemic stroke. Melatonin treatment significantly decreased infarct volume and cerebral apoptosis; mitigated endoplasmic reticulum stress and mitochondrial dysfunction; and inhibited CI/R injury-induced oxidative/nitrative stress and nuclear factor-κB activation, which was eradicated in RORα-deficient mice. Collectively, current findings suggest that RORα is a novel endogenous neuroprotective receptor, and a pivotal mediator of melatonin's suppressive effects against CI/R injury.

ABCA1/ApoE/HDL Signaling Pathway Facilitates Myelination and Oligodendrogenesis after Stroke

ATP-binding cassette transporter A1 (ABCA1) plays an important role in the regulation of apolipoprotein E (ApoE) and the biogenesis of high-density lipoprotein (HDL) cholesterol in the mammalian brain. Cholesterol is a major source for myelination. Here, we investigate whether ABCA1/ApoE/HDL contribute to myelin repair and oligodendrogenesis in the ischemic brain after stroke. Specific brain ABCA1-deficient (ABCA1^-B/-B) and ABCA1-floxed (ABCA1^fl/fl) control mice were subjected to permanent distal middle-cerebral-artery occlusion (dMCAo) and were intracerebrally administered (1) artificial mouse cerebrospinal fluid (CSF) as vehicle control, (2) human plasma HDL3, and (3) recombined human ApoE2 starting 24 h after dMCAo for 14 days. All stroke mice were sacrificed 21 days after dMCAo. The ABCA1^-B/-B–dMCAo mice exhibit significantly reduced myelination and oligodendrogenesis in the ischemic brain as well as decreased functional outcome 21 days after stroke compared with ABCA1^fl/fl mice; administration of human ApoE2 or HDL3 in the ischemic brain significantly attenuates the deficits in myelination and oligodendrogenesis in ABCA1^-B/-B–dMCAo mice ( p < 0.05, n = 9/group). In vitro, ABCA1^-B/-B reduces ApoE expression and decreases primary oligodendrocyte progenitor cell (OPC) migration and oligodendrocyte maturation; HDL3 and ApoE2 treatment significantly reverses ABCA1^-B/-B-induced reduction in OPC migration and oligodendrocyte maturation. Our data indicate that the ABCA1/ApoE/HDL signaling pathway contributes to myelination and oligodendrogenesis in the ischemic brain after stroke.

Protective Effects of Antioxidant Polyphenols against Hyperglycemia-Mediated Alterations in Cerebral Endothelial Cells and a Mouse Stroke Model

SCOPE

Hyperglycemia alters cerebral endothelial cell and blood-brain barrier functions, aggravating cerebrovascular complications such as stroke during diabetes. Redox and inflammatory changes play a causal role. This study evaluates polyphenol protective effects in cerebral endothelial cells and a mouse stroke model during hyperglycemia.

METHODS AND RESULTS

Murine bEnd.3 cerebral endothelial cells and a mouse stroke model are exposed to a characterized, polyphenol-rich extract of Antirhea borbonica or its predominant constituent caffeic acid, during hyperglycemia. Polyphenol effects on redox, inflammatory and vasoactive markers, infarct volume, and hemorrhagic transformation are determined. In vitro, polyphenols improve reactive oxygen species levels, Cu/Zn superoxide dismutase activity, and both NAPDH oxidase 4 and nuclear factor erythroid 2-related factor 2 (Nrf2) gene expression deregulated by high glucose. Polyphenols reduce Nrf2 nuclear translocation and counteract nuclear factor-ĸappa B activation, interleukin-6 secretion, and the altered production of vasoactive markers mediated by high glucose. In vivo, polyphenols reduce cerebral infarct volume and hemorrhagic transformation aggravated by hyperglycemia. Polyphenols attenuate redox changes, increase vascular endothelial-Cadherin production, and decrease neuro-inflammation in the infarcted hemisphere.

CONCLUSION

Polyphenols protect against hyperglycemia-mediated alterations in cerebral endothelial cells and a mouse stroke model. It is relevant to assess polyphenol benefits to improve cerebrovascular damages during diabetes.

Alpha-pinene exerts neuroprotective effects via anti-inflammatory and anti-apoptotic mechanisms in a rat model of focal cerebral ischemia-reperfusion

BACKGROUND

Ischemic stroke is a severe neurological disorder that affected millions of people worldwide. Neuro-inflammation and apoptosis play an essential role in the pathogenesis of neuronal death during ischemic stroke. Alpha-pinene is a bicyclic terpenoid with anti-inflammatory and anti-apoptotic activities. Accordingly, the main purpose of this study was to assess the protective effect of α-pinene in ischemic stroke.

MATERIALS AND METHODS

To induce ischemic stroke in male Wistar rats, the middle cerebral artery was occluded for 60 min followed by 24 h reperfusion. Alpha-pinene was injected intraperitoneally at the beginning of reperfusion. A day after reperfusion, the neurological deficits, volume of infarct area, and blood-brain barrier (BBB) permeability were evaluated. The mRNA expression of inflammatory cytokines as well as pro- and anti-apoptotic genes was assessed by using reverse transcription-polymerase chain reaction. The protein levels of inflammatory cytokines were also measured by ELISA method.

RESULTS

The results showed that α-pinene (50 and 100 mg/kg) significantly improved sensorimotor function and decreased the volume of infarct area in the brain. The high permeability of BBB was also alleviated by α-pinene (50 and 100 mg/kg) in ischemic areas. Besides, α-pinene (100 mg/kg) attenuated neuro-inflammation through decreasing both the gene and protein expression of TNF-α and IL-1β in the hippocampus, cortex, and striatum. Besides, α-pinene (100 mg/kg) suppressed apoptosis via downregulation of the pro-apoptotic Bax mRNA expression with a concomitant upregulation of anti-apoptotic Bcl-2 gene expression.

CONCLUSIONS

Overall, it was concluded that α-pinene exerts neuroprotective effect during ischemic stroke through attenuating neuroinflammation and inhibition of apoptosis.

Hydrogen inhibits microglial activation and regulates microglial phenotype in a mouse middle cerebral artery occlusion model

Microglia participate in bi-directional control of brain repair after stroke. Previous studies have demonstrated that hydrogen protects brain after ischemia/reperfusion (I/R) by inhibiting inflammation, but the specific mechanism of anti-inflammatory effect of hydrogen is poorly understood. The goal of our study is to investigate whether inhalation of high concentration hydrogen (HCH) is able to attenuate I/R-induced microglia activation. Eighty C57B/L male mice were divided into four groups: sham, I/R, I/R + HCH and I/R + N₂/O₂ groups. Assessment of animals happened in “blind” matter. I/R was induced by occlusion of middle cerebral artery for one hour). After one hour, filament was withdrawn, which induced reperfusion. Hydrogen treated I/R animals inhaled mix of 66.7% H₂ balanced with O₂ for 90 minutes, starting immediately after initiation of reperfusion. Control animals (N₂/O₂) inhaled mix in which hydrogen was replaced with N₂ for the same time (90 minutes). The brain injury, such as brain infarction and development of brain edema, as well as neurobehavioral deficits were determined 23 hours after reperfusion. Effect of HCH on microglia activation in the ischemic penumbra was investigated by immunostaining also 23 hours after reperfusion. mRNA expression of inflammation related genes was detected by PCR. Our results showed that HCH attenuated brain injury and consequently reduced neurological dysfunction after I/R. Furthermore, we demonstrated that HCH directed microglia polarization towards anti-inflammatory M2 polarization. This study indicates hydrogen may exert neuroprotective effects by inhibiting the microglial activation and regulating microglial polarization. This study was conducted in agreement with the Animal Care and Use Committee (IACUC) and Institutional Animal Care guidelines regulation (Shanghai Jiao Tong University, China (approval No. A2015-011) in November 2015.

Combinational Approach of Genetic SHP-1 Suppression and Voluntary Exercise Promotes Corticospinal Tract Sprouting and Motor Recovery Following Brain Injury

Background. Brain injury often causes severe motor dysfunction, leading to difficulties with living a self-reliant social life. Injured neural circuits must be reconstructed to restore functions, but the adult brain is limited in its ability to restore neuronal connections. The combination of molecular targeting, which enhances neural plasticity, and rehabilitative motor exercise is an important therapeutic approach to promote neuronal rewiring in the spared circuits and motor recovery. Objective. We tested whether genetic reduction of Src homology 2-containing phosphatase-1 (SHP-1), an inhibitor of brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB) signaling, has synergistic effects with rehabilitative training to promote reorganization of motor circuits and functional recovery in a mouse model of brain injury. Methods. Rewiring of the corticospinal circuit was examined using neuronal tracers following unilateral cortical injury in control mice and in Shp-1 mutant mice subjected to voluntary exercise. Recovery of motor functions was assessed using motor behavior tests. Results. We found that rehabilitative exercise decreased SHP-1 and increased BDNF and TrkB expression in the contralesional motor cortex after the injury. Genetic reduction of SHP-1 and voluntary exercise significantly increased sprouting of corticospinal tract axons and enhanced motor recovery in the impaired forelimb. Conclusions. Our data demonstrate that combining voluntary exercise and SHP-1 suppression promotes motor recovery and neural circuit reorganization after brain injury.

Delayed recanalization after MCAO ameliorates ischemic stroke by inhibiting apoptosis via HGF/c-Met/STAT3/Bcl-2 pathway in rats

The activation of tyrosine kinase receptor c-Met by hepatocyte growth factor (HGF) showed an anti-apoptotic effect in numerous disease models. This study aimed to investigate the neuroprotective mechanism of the HGF/c-Met axis-mediated anti-apoptosis underlying the delayed recanalization in a rat model of middle cerebral artery occlusion (MCAO). Permanent MCAO model (pMCAO) was induced by intravascular filament insertion. Recanalization was induced by withdrawing the filament at 3 days after MCAO (rMCAO). HGF levels in the blood serum and brain tissue expressions of HGF, c-Met, phosphorylated-STAT3 (p-STAT3), STAT3, Bcl-2, Bax, cleaved caspase-3(CC3) were assessed using ELISA and western blot, respectively. To study the mechanism, HGF small interfering ribonucleic acid (siRNA) and c-Met inhibitor, su11274, were administered intracerebroventricularly (i.c.v.) or intranasally, respectively. The concentration of HGF in the serum was increased significantly after MCAO. Brain expression of HGF was increased after MCAO and peaked at 3 days after recanalization. HGF and c-Met were both co-localized with neurons. Compared to rats received permanent MCAO, delayed recanalization after MCAO decreased the infarction volume, inhibited neuronal apoptosis, and improved neurobehavioral function, increased expressions of p-STAT3 and its downstream Bcl-2. Mechanistic studies indicated that HGF siRNA and su11274 reversed the neuroprotection including anti-apoptotic effects provided by delayed recanalization. In conclusion, the delayed recanalization after MCAO increased the expression of HGF in the brain, and reduced the infarction and neuronal apoptosis after MCAO, partly via the activation of the HGF/c-Met/STAT3/Bcl-2 signaling pathway. The delayed recanalization may serve as a therapeutic alternative for a subset of ischemic stroke patients.

Cathodal tDCS exerts neuroprotective effect in rat brain after acute ischemic stroke

BACKGROUND

Transcranial direct current stimulation (tDCS) is a non-invasive brain modulation technique that has been proved to exert beneficial effects in the acute phase of stroke. To explore the underlying mechanism, we investigated the neuroprotective effects of cathodal tDCS on brain injury caused by middle cerebral artery occlusion (MCAO).

RESULTS

We established the MCAO model and sham MCAO model with an epicranial electrode implanted adult male Sprague-Dawley rats, and then they were randomly divided into four groups (MCAO + tDCS, MCAO + sham tDCS (Sham), Control + tDCS and Control + Sham group). In this study, the severity degree of neurological deficit, the morphology of brain damage, the apoptosis, the level of neuron-specific enolase and inflammatory factors, the activation of glial cells was detected. The results showed that cathodal tDCS significantly improved the level of neurological deficit and the brain morphology, reduced the brain damage area and apoptotic index, and increased the number of Nissl body in MCAO rats, compared with MCAO + Sham group. Meanwhile, the high level of NSE, inflammatory factors, Caspase 3 and Bax/Bcl2 ratio in MCAO rats was reduced by cathodal tDCS. Additionally, cathodal tDCS inhibited the activation of astrocyte and microglia induced by MCAO. No difference was found in two Control groups.

CONCLUSION

Our results suggested that cathodal tDCS could accelerate the recovery of neurologic deficit and brain damage caused by MCAO. The inhibition of neuroinflammation and apoptosis resulted from cathodal tDCS may be involved in the neuroprotective process.

Artesunate promotes the proliferation of neural stem/progenitor cells and alleviates Ischemia-reperfusion Injury through PI3K/Akt/FOXO-3a/p27kip1 signaling pathway

Stroke is one of the leading causes of death worldwide that also result in long-term disability. Endogenous neural stem/progenitor cells (NSPCs) within subventricular (SVZ) and dentate gyrus (DG) zone, stimulated by cerebral infarction, can promote neural function recovery. However, the proliferation of eNSPCs triggered by ischemia is not enough to induce neural repair, which may contribute to the permanent disability in stroke patients. In this study, our results showed that following the treatment with artesunate (ART, 150 mg/kg), the functional recovery was significantly improved, the infarct volume was notably reduced, and the expression of Nestin, a proliferation marker of NSPCs in the infarcted cortex, was also increased. Additionally, the proliferative activity of NSPCs with or without oxygen-glucose deprivation/reperfusion was significantly promoted by ART treatment, and the therapeutic concentration was 0.8 μmol/L (without OGD/R) or 0.4 μmol/L (with OGD/R) in the in vitro model. Furthermore, the effects of ART can be abolished by the treatment of PI3K inhibitor wortmannin. The expression levels of related molecules in PI3K/Akt/FOXO-3a/p27^kip1 signaling pathway (p-AKT, p-FOXO-3a, p27^kip1) were examined using western blotting. The results suggested ART could inhibit the transcriptional function of FOXO-3a by inducing its phosphorylation, subsequently downregulating p27^kip1 and enhancing neural stem cell proliferation in the infarcted cortex via PI3K/AKT signaling, further alleviating ischemia-reperfusion injury after ischemic stroke.

Human umbilical cord blood cells rescued traumatic brain injury-induced cardiac and neurological deficits

Background

Traumatic brain injury (TBI) evokes neurological deficits and induces cardiac dysfunction. Treatment with human umbilical cord blood cells (HUCBCs) represents a potential therapeutic strategy for TBI-induced neurological deficits. The present study aimed to determine whether HUCBCs could ameliorate the cardiac dysfunction and neurological deficits induced by TBI.

Methods

Adult male C57BL/6J mice were subjected to controlled cortical impact (CCI)-induced TBI and were treated with either HUCBCs (1×10⁶) or phosphate-buffered saline (PBS), via tail vein injections, 3 days after TBI. Neurological and cognitive functions were subsequently evaluated at multiple time points after TBI and cardiac function was assessed by echocardiography 3 and 30 days after TBI. Brain and heart tissues were paraffin-embedded 30 days after TBI. Hematoxylin and eosin (H&E) staining was performed on brain tissue sections to calculate the brain damage volume, and Picro Sirius Red (PSR) staining was performed on heart tissue sections to evaluate myocardial fibrosis. Terminal deoxynucleotide transferase dUTP nick end labeling (TUNEL) staining was employed to assess cell apoptosis 30 days after TBI. Transforming growth factor-beta (TGF-β) and NADPH oxidase-2 (NOX2) levels were assessed to evaluate inflammation and oxidative stress levels 30 days after TBI.

Results

TBI elicited acute and chronic cardiac deficits, identified by decreased left ventricular ejection fraction (LVEF) and fractional shortening (LVFS) values 3 and 30 days after TBI, in addition to neurological and cognitive deficits. TBI mice treated with HUCBCs exhibited enhanced LVEF and FS values 30 days after TBI compared with untreated TBI controls. HUCBC treatment significantly improved neurological and cognitive functions and reduced cardiomyocyte apoptosis, inflammatory response, oxidative stress, and cardiac fibrosis in heart tissues 30 days after TBI.

Conclusions

TBI induced both neurological deficits and cardiac dysfunction in mice, which were ameliorated by HUCBC treatment. The anti-inflammatory activities of HUCBCs may contribute to these observed therapeutic effects.

Transcranial direct current stimulation treated by multilead brain reflex instrument accelerates neural functional recovery in a rat model of stroke

PURPOSE

Clinical research suggests that transcranial direct current stimulation (tDCS) at bilateral supraorbital foramen and inferior orbital rim and nose intersections may facilitate rehabilitation after stroke. However, the underlying neurobiological mechanisms of tDCS remain poorly understood, impeding its clinical application. Here, we investigated the effect of tDCS applied after stroke on neural cells.

MATERIALS AND METHODS

Middle cerebral arterial occlusion (MCAO) reperfusion was induced in rats. Animals with comparable infarcts were randomly divided into MCAO group and MCAO + tDCS group. Recovery of neurological function was assessed behaviorally by modified neurological severity score (mNSS). Ischemic tissue damage verified histologically by TTC and HE staining. Immunohistochemical staining, real-time qPCR, and western blot were applied to determine the changes of neural cells in ischemic brains.

RESULTS

The results reveal that tDCS treated by multilead brain reflex instrument can promote the recovery of neurological function, remarkably reduce cerebral infarct volume, promote brain tissue rehabilitation, and can effectively inhibit astrocytosis and enhance neuronal survival and synaptic function in ischemic brains.

CONCULSIONS

Our study suggests that tDCS treated by multilead brain reflex instrument could be prospectively developed into a clinical treatment modality.

A study of optimal concentration range and time window of sevoflurane preconditioning for brain protection in MCAO rats

Background

Sevoflurane preconditioning improves brain function in MCAO rats, and there are several methods for determining appropriate concentration and time windows for preconditioning. This study investigated the brain protective effects with a single sevoflurane preconditioning at different concentrations and different time windows on MCAO rats.

Methods

Adult Sprague-dawley rats were randomly assigned to 14 groups. The rats in the sevoflurane preconditioning group inhaled 0.5 MAC, 1.0 MAC, and 1.3 MAC sevoflurane, respectively for 3 h, and then MCAO models were established at 6 h, 12 h, 24 h, and 48 h. MCAO and sham groups underwent no preconditioning with sevoflurane. The neurological severity score, cerebral infarct volume and brain water content of the rats were measured 24 h after reperfusion.

Results

After inhalation of 1.3 MAC sevoflurane for 3 h of preconditioning, the MCAO model was established after 24 h. This preconditioning improved the neurological severity score, reduce cerebral infarct volume and brain water content in MCAO rats. After inhalation of 1.0 MAC sevoflurane for 3 h of preconditioning, MCAO model established after 24 h reduced the cerebral infarct volume and brain water content of MCAO rats, but the neurological severity score showed no significant improvement, and no significant brain protective effects were observed at other concentrations and time windows.

Conclusions

These results suggested that after inhalation of 1.3 MAC sevoflurane for 3 h of preconditioning, MCAO model established after 24 h demonstrated significant brain protective effects in MCAO rats.

Remote liver ischaemic preconditioning protects rat brain against cerebral ischaemia-reperfusion injury by activation of an AKT-dependent pathway

NEW FINDINGS

What is the central question of this study? Can remote liver ischaemic preconditioning (RLIPC) protect rat brain against cerebral ischaemia-reperfusion injury? What is the main finding and its importance? Pretreatment with RLIPC reduced cerebral infarct volume, improved neurological outcomes and inhibited neuron apoptosis. RLIPC led to increased phosphorylation of AKT, while inhibition of AKT abolished the effects of RLIPC. Our data suggest that liver ischaemic preconditioning exerts a strong neuroprotective effect against cerebral ischaemia-reperfusion injury by activating an AKT-dependent pathway.

ABSTRACT

Remote limb ischaemic preconditioning has been shown to have beneficial effects in protecting brains against ischaemia-reperfusion (I/R) injury. However, little is known regarding the effect of remote liver ischaemic conditioning (RLIPC). We therefore investigated the effect of RLIPC on brain tissues suffering from I/R injury. Rats were randomly assigned to a sham group, a control group or a RLIPC group. Rats in all groups except for the sham group received middle cerebral artery occlusion (MCAO) for 1 h, followed by 48 h of reperfusion. For the RLIPC rats, four cycles of 5 min of liver ischaemia (portal vein, hepatic arterial and venous trunk occlusion) with 5 min intermittent reperfusion were carried out before cerebral ischaemia. Infarct volume was assessed after 48 h of reperfusion. Blood samples were taken for serum lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) tests. Morphological changes of cortical tissue and cellular apoptosis were determined. Right cortex tissues were taken for western blotting measurements. Our data demonstrate that RLIPC reduced cerebral I/R injury, decreased the volume of the MCAO-evoked infarct region, decreased serum levels of LDH and CK-MB, and reduced neurological deficits and apoptosis after I/R injury. Moreover, rats receiving RLIPC showed increased cortical AKT phosphorylation, but protein phosphorylation level was unchanged in the survivor activating factor enhancement (SAFE) signalling pathway. Accordingly, inhibition of AKT with wortmannin abolished the neuroprotective action of liver preconditioning. Our study showed for the first time that liver ischaemic preconditioning effectively protects brain against cerebral I/R injury by activating an AKT-dependent pathway.

Impaired Collateral Flow in Pial Arterioles of Aged Rats During Ischemic Stroke

Cerebral collateral circulation and age are critical factors in determining outcome from acute ischemic stroke. Aging may lead to rarefaction of cerebral collaterals, and thereby accelerate ischemic injury by reducing penumbral blood flow. Dynamic changes in pial collaterals after onset of cerebral ischemia may vary with age but have not been extensively studied. Here, laser speckle contrast imaging (LSCI) and two-photon laser scanning microscopy (TPLSM) were combined to monitor cerebral pial collaterals between the anterior cerebral artery (ACA) and the middle cerebral artery (MCA) in young adult and aged male Sprague Dawley rats during distal middle cerebral artery occlusion (dMCAo). Histological analysis showed that aged rats had significantly greater volumes of ischemic damage than young rats. LSCI showed that cerebral collateral perfusion declined over time after stroke in aged and young rats, and that this decline was significantly greater in aged rats. TPLSM demonstrated that pial arterioles narrowed faster after dMCAo in aged rats compared to young adult rats. Notably, while arteriole vessel narrowing was comparable 4.5 h after ischemic onset in aged and young adult rats, red blood cell velocity was stable in young adults but declined over time in aged rats. Overall, red blood cell flux through pial arterioles was significantly reduced at all time-points after 90 min post-dMCAo in aged rats relative to young adult rats. Thus, collateral failure is more severe in aged rats with significantly impaired pial collateral dynamics (reduced diameter, red blood cell velocity, and red blood cell flux) relative to young adult rats.

CD133+Exosome Treatment Improves Cardiac Function after Stroke in Type 2 Diabetic Mice

Cardiac complications post-stroke are common, and diabetes exacerbates post-stroke cardiac injury. In this study, we tested whether treatment with exosomes harvested from human umbilical cord blood derived CD133+ cells (CD133+Exo) improves cardiac function in type 2 diabetes mellitus (T2DM) stroke mice. Adult (3-4 m), male, BKS.Cg-m+/+Lepr^db/J (db/db, T2DM) and non-DM (db+) mice were randomized to sham or photothrombotic stroke groups. T2DM-stroke mice were treated with phosphate-buffered saline (PBS) or CD133+Exo (20 μg, i.v.) at 3 days after stroke. T2DM sham and T2DM+CD133+Exo treatment groups were included as controls. Echocardiography was performed, and mice were sacrificed at 28 days after stroke. Cardiomyocyte hypertrophy, myocardial capillary density, interstitial fibrosis, and inflammatory factor expression were measured in the heart. MicroRNA-126 expression and its target gene expression were measured in the heart. T2DM mice exhibit significant cardiac deficits such as decreased left ventricular ejection fraction (LVEF) and shortening fraction (LVSF), increased left ventricular diastolic dimension (LVDD), and reduced heart rate compared to non-DM mice. Stroke in non-DM and T2DM mice significantly decreases LVEF compared to non-DM and T2DM-sham, respectively. Cardiac dysfunction is worse in T2DM-stroke mice compared to non-DM-stroke mice. CD133+Exo treatment of T2DM-stroke mice significantly improves cardiac function identified by increased LVEF and decreased LVDD compared to PBS treated T2DM-stroke mice. In addition, CD133+Exo treatment significantly decreases body weight and blood glucose but does not decrease lesion volume in T2DM-stroke mice. CD133+Exo treatment of T2DM mice significantly decreases body weight and blood glucose but does not improve cardiac function. CD133+Exo treatment in T2DM-stroke mice significantly decreases myocardial cross-sectional area, interstitial fibrosis, transforming growth factor beta (TGF-β), numbers of M1 macrophages, and oxidative stress markers 4-HNE (4-hydroxynonenal) and NADPH oxidase 2 (NOX2) in heart tissue. CD133+Exo treatment increases myocardial capillary density in T2DM-stroke mice as well as upregulates endothelial cell capillary tube formation in vitro. MiR-126 is highly expressed in CD133+Exo compared to exosomes derived from endothelial cells. Compared to PBS treatment, CD133+Exo treatment significantly increases miR-126 expression in the heart and decreases its target gene expression such as Sprouty-related, EVH1 domain-containing protein 1 (Spred-1), vascular cell adhesion protein (VCAM), and monocyte chemoattractant protein 1 (MCP1) in the heart of T2DM-stroke mice. CD133+Exo treatment significantly improves cardiac function in T2DM-stroke mice. The cardio-protective effects of CD133+Exo in T2DM-stroke mice may be attributed at least in part to increasing miR-126 expression and decreasing its target protein expression in the heart, increased myocardial capillary density and decreased cardiac inflammatory factor expression.

Extended preclinical investigation of lactate for neuroprotection after ischemic stroke

Lactate has been shown to have beneficial effect both in experimental ischemia–reperfusion models and in human acute brain injury patients. To further investigate lactate’s neuroprotective action in experimental in vivo ischemic stroke models prior to its use in clinics, we tested (1) the outcome of lactate administration on permanent ischemia and (2) its compatibility with the only currently approved drug for the treatment of acute ischemic stroke, recombinant tissue plasminogen activator (rtPA), after ischemia–reperfusion. We intravenously injected mice with 1 µmol/g sodium l-lactate 1 h or 3 h after permanent middle cerebral artery occlusion (MCAO) and looked at its effect 24 h later. We show a beneficial effect of lactate when administered 1 h after ischemia onset, reducing the lesion size and improving neurological outcome. The weaker effect observed at 3 h could be due to differences in the metabolic profiles related to damage progression. Next, we administered 0.9 mg/kg of intravenous (iv) rtPA, followed by intracerebroventricular injection of 2 µL of 100 mmol/L sodium l-lactate to treat mice subjected to 35-min transient MCAO and compared the outcome (lesion size and behavior) of the combined treatment with that of single treatments. The administration of lactate after rtPA has positive influence on the functional outcome and attenuates the deleterious effects of rtPA, although not as strongly as lactate administered alone. The present work gives a lead for patient selection in future clinical studies of treatment with inexpensive and commonly available lactate in acute ischemic stroke, namely patients not treated with rtPA but mechanical thrombectomy alone or patients without recanalization therapy.

Neuroprotective Effects of Selective Inhibition of Histone Deacetylase 3 in Experimental Stroke

Histone deacetylase 3 (HDAC3) has been implicated as neurotoxic in several neurodegenerative conditions. However, the role of HDAC3 in ischemic stroke has not been thoroughly explored. We tested the hypothesis that selective inhibition of HDAC3 after stroke affords neuroprotection. Adult male Wistar rats (n = 8/group) were subjected to 2 h of middle cerebral artery occlusion (MCAO), and randomly selected animals were treated intraperitoneally twice with either vehicle (1% Tween 80) or a selective HDAC3 inhibitor (RGFP966, 10 mg/kg) at 2 and 24 h after MCAO. Long-term behavioral tests were performed up to 28 days after MCAO. Another set of rats (n = 7/group) were sacrificed at 3 days for histological analysis. Immunostaining for HDAC3, acetyl-Histone 3 (AcH3), NeuN, TNF-alpha, toll-like receptor 4 (TLR4), cleaved caspase-3, cleaved poly (ADP-ribose) polymerase (PARP), Akt, and TUNEL were performed. Selective HDAC3 inhibition improved long-term functional outcome (p < 0.05) and reduced infarct volume (p < 0.0001). HDAC3 inhibition increased levels of AcH3 in the ischemic brain (p = 0.016). Higher levels of AcH3 were significantly correlated with better neurological scores and smaller infarct volumes (r = 0.74, p = 0.002; r = 0.6, p = 0.02, respectively). The RGFP966 treatment reduced apoptosis-TUNEL+, cleaved caspase-3+, and cleaved PARP+ cells-and neuroinflammation-TNF-alpha+ and TLR4+ cells-in the ischemic border compared to vehicle control (p < 0.05). The RGFP966 treatment also increased Akt expression in the ipsilateral cortex (p < 0.001). Selective HDAC3 inhibition after stroke improves long-term neurological outcome and decreases infarct volume. The neuroprotective effects of HDAC3 inhibition are associated with a reduction in apoptosis and inflammation and upregulation of the Akt pathway.

Improvement in mitochondrial function underlies the effects of ANNAO tablets on attenuating cerebral ischemia-reperfusion injuries

ETHNOPHARMACOLOGICAL RELEVANCE

ANNAO tablets derive from Chinese classical prescriptions of Angong Niuhuang Pills with modified compositions, which have been singly or combined used for stoke associated neurological disorders. However the underlying mechanism is not yet well-defined, the present study investigated its anti-ischemic effects in rat middle cerebral artery occlusion (MCAO) model and focused on mitochondrial quality control.

MATERIALS AND METHODS

Rats were subjected to 2 h of brain ischemia followed by 1 day or up to 7 days of reperfusion. Vehicle, ANNAO tablets or Edaravone were given at 1h after the start of reperfusion for 1 day or successive 7 days in MCAO rats. For the behavior assessment, Longa test and modified Neurological Severity Scores (m NSS) test were performed. Following the behavioral assessment, we assessed the protein expressions related to mitochondrial function. Moreover, we also assessed the neuroprotective effects of ANNAO tablets by immunohistochemical analysis.

RESULTS

Compared with sham rats, ANNAO tablets improved the behavioral performance and decreased the infarction volume in the MCAO rats. Western blotting results showed that ANNAO tablets altered the expression level of multiple proteins related to mitochondrial function, elevated the ratio of Bcl-2/Bax and inhibited the apoptosis. Additionally, ANNAO tablets increased the number of NeuN positive neurons.

CONCLUSIONS

The obtained data demonstrated that ANNAO tablets exhibited an obvious anti-cerebral ischemia-reperfusion effect, which could be attributed to the improvement of mitochondrial quality control.

Modulation of brain cation-Cl- cotransport via the SPAK kinase inhibitor ZT-1a

The SLC12A cation-Cl^- cotransporters (CCC), including NKCC1 and the KCCs, are important determinants of brain ionic homeostasis. SPAK kinase (STK39) is the CCC master regulator, which stimulates NKCC1 ionic influx and inhibits KCC-mediated efflux via phosphorylation at conserved, shared motifs. Upregulation of SPAK-dependent CCC phosphorylation has been implicated in several neurological diseases. Using a scaffold-hybrid strategy, we develop a novel potent and selective SPAK inhibitor, 5-chloro-N-(5-chloro-4-((4-chlorophenyl)(cyano)methyl)-2-methylphenyl)-2-hydroxybenzamide ("ZT-1a"). ZT-1a inhibits NKCC1 and stimulates KCCs by decreasing their SPAK-dependent phosphorylation. Intracerebroventricular delivery of ZT-1a decreases inflammation-induced CCC phosphorylation in the choroid plexus and reduces cerebrospinal fluid (CSF) hypersecretion in a model of post-hemorrhagic hydrocephalus. Systemically administered ZT-1a reduces ischemia-induced CCC phosphorylation, attenuates cerebral edema, protects against brain damage, and improves outcomes in a model of stroke. These results suggest ZT-1a or related compounds may be effective CCC modulators with therapeutic potential for brain disorders associated with impaired ionic homeostasis.

Effects of neural stem cell-derived extracellular vesicles on neuronal protection and functional recovery in the rat model of middle cerebral artery occlusion

Stroke imposes a long-term neurological disability with limited effective treatments available for neuronal recovery. Transplantation of neural stem cells (NSCs) is reported to improve functional outcomes in the animal models of brain ischemia. However, the use of cell therapy is accompanied by adverse effects, so research is growing to use cell-free extracts such as extracellular vesicles (EVs) for targeting brain diseases. In the current study, male Wistar albino rats (20 months old) were subjected to middle cerebral artery occlusion (MCAO). Then, EVs (30 μg) were injected at 2 hours after stroke onset via an intracerebroventricular (ICV) route. Measurements were done at day 7 post-MCAO. EVs administration reduced lesion volume and steadily improved spontaneous locomotor activity. EVs administration also reduced microgliosis (ionized calcium-binding adaptor molecule 1 (Iba1)⁺ cells) and apoptotic (terminal-deoxynucleotidyl transferase mediated nick end labelling [TUNEL]) positive cells and increased neuronal survival (neuronal nuclear (NeuN)⁺ cells) in the ischemic boundary zone (IBZ). However, it had no effect on neurogenesis within the sub-ventricular zone (SVZ) but decreased cellular migration toward the IBZ (doublecortin (DCX)⁺ cells). The results of this study showed neuroprotective and restorative mechanisms of NSC-EVs administration, which may offer new avenues for therapeutic intervention of brain ischemia. SIGNIFICANCE OF THE STUDY: Based on our results, EVs administration can effectively reduce microglial density and neuronal apoptosis, thereby steadily improves functional recovery after MCAO. These findings provide the beneficial effect of NSC-EVs as a new biological treatment for stroke.

Cofilin-actin rod formation in experimental stroke is attenuated by therapeutic hypothermia and overexpression of the inducible 70 kD inducible heat shock protein (Hsp70)

BACKGROUND AND PURPOSE

Cofilin-actin rods are covalently linked aggregates of cofilin-1 and actin. Under ischemic conditions, these rods have been observed in neuronal dendrites and axons and may contribute to the loss of these processes. Hypothermia (Hypo) and the 70 kD inducible heat shock protein (Hsp70) are both known to improve outcomes after stroke, but the mechanisms are uncertain. Here, we evaluated the effect of these factors on cofilin-actin rod formation in a mouse model of stroke.

MATERIALS AND METHODS

Mice were subjected to distal middle cerebral artery occlusion (dMCAO) and treated with Hypo using a paradigm previously shown to be neuroprotective. We similarly studied mice that overexpressed transgenic (Tg) or were deficient knockout (Ko) in the inducible 70 kDa heat shock protein (Hsp70), also previously shown to be protective by our group and others. Cofilin-actin rod formation was assessed by histological analysis at 4 and 24 h after dMCAO. Its expression was analyzed in three different regions, namely, infarct core (the center of the infarct), middle cerebral artery (MCA) borderzone (the edge of the brain regions supplied by the MCA), and the ischemic borderzone (border of ischemic lesion). Ischemic lesion size and neurological deficits were also assessed.

RESULTS

Both Hypo-treated and Hsp70 Tg mice had smaller lesion sizes and improved neurological outcomes, whereas Hsp70 Ko mice had larger lesion sizes and worsened neurological outcomes. Cofilin-actin rods were increased after stroke, but were reduced by therapeutic Hypo and in Hsp70 Tg mice. In contrast, cofilin-actin rods were increased in ischemic brains of Hsp70 Ko mice.

CONCLUSIONS

Cofilin-actin rod formation was suppressed under the conditions of neuroprotection and increased under circumstances where outcome was worsened. This suggests that cofilin-actin rods may act to participate in or exacerbate ischemic pathology and warrants further study as a potential therapeutic target.

Triiodothyronine modulates neuronal plasticity mechanisms to enhance functional outcome after stroke

The development of new therapeutic approaches for stroke patients requires a detailed understanding of the mechanisms that enhance recovery of lost neurological functions. The efficacy to enhance homeostatic mechanisms during the first weeks after stroke will influence functional outcome. Thyroid hormones (TH) are essential regulators of neuronal plasticity, however, their role in recovery related mechanisms of neuronal plasticity after stroke remains unknown. This study addresses important findings of 3,5,3′-triiodo-L-thyronine (T₃) in the regulation of homeostatic mechanisms that adjust excitability – inhibition ratio in the post-ischemic brain. This is valid during the first 2 weeks after experimental stroke induced by photothrombosis (PT) and in cultured neurons subjected to an in vitro model of acute cerebral ischemia. In the human post-stroke brain, we assessed the expression pattern of TH receptors (TR) protein levels, important for mediating T₃ actions.

Our results show that T₃ modulates several plasticity mechanisms that may operate on different temporal and spatial scales as compensatory mechanisms to assure appropriate synaptic neurotransmission. We have shown in vivo that long-term administration of T₃ after PT significantly (1) enhances lost sensorimotor function; (2) increases levels of synaptotagmin 1&2 and levels of the post-synaptic GluR2 subunit in AMPA receptors in the peri-infarct area; (3) increases dendritic spine density in the peri-infarct and contralateral region and (4) decreases tonic GABAergic signaling in the peri-infarct area by a reduced number of parvalbumin⁺ / c-fos⁺ neurons and glutamic acid decarboxylase 65/67 levels. In addition, we have shown that T₃ modulates in vitro neuron membrane properties with the balance of inward glutamate ligand-gated channels currents and decreases synaptotagmin levels in conditions of deprived oxygen and glucose. Interestingly, we found increased levels of TRβ1 in the infarct core of post-mortem human stroke patients, which mediate T₃ actions. Summarizing, our data identify T₃ as a potential key therapeutic agent to enhance recovery of lost neurological functions after ischemic stroke.

Automated Assessment of Hematoma Volume of Rodents Subjected to Experimental Intracerebral Hemorrhagic Stroke by Bayes Segmentation Approach

Simulating a clinical condition of intracerebral hemorrhage (ICH) in animals is key to research on the development and testing of diagnostic or treatment strategies for this high-mortality disease. In order to study the mechanism, pathology, and treatment for hemorrhagic stroke, various animal models have been developed. Measurement of hematoma volume is an important assessment parameter to evaluate post-ICH outcomes. However, due to tissue preservation conditions and variables in digitization, quantification of hematoma volume is usually labor intensive and sometimes even subjective. The objective of this study is to develop an automated method that can accurately and efficiently obtain unbiased cerebral hematoma volume. We developed an application (MATLAB program) that can delineate the brain slice from the background and use the Hue information in the Hue/Saturation/Value (HSV) color space to segment the hematoma region. The segmentation threshold of Hue is calculated based on the Bayes classifier theorem so that the minimum error is mathematically ensured and automated processing is enabled. To validate the developed method, we compared the outcomes from the developed method with the hemoglobin content by the spectrophotometric assay method. The results were linearly correlated with statistical significance. The method was also validated by digital phantoms with an error less than 5% compared with the ground truth from the phantoms. Hematoma volumes yielded by the automated processing and those obtained by the operator's manual operation are highly correlated. This automated segmentation approach can be potentially used to quantify hemorrhagic outcomes in rodent stroke models in an unbiased and efficient way.

DPP-4 Inhibitor Linagliptin is Neuroprotective in Hyperglycemic Mice with Stroke via the AKT/mTOR Pathway and Anti-apoptotic Effects

Dipeptidyl peptidase 4 (DPP-4) inhibitors have been shown to have neuroprotective effects in diabetic patients suffering from stroke, but less research has focused on patients with mild hyperglycemia below the threshold for a diagnosis of diabetes. In this investigation, a hyperglycemic mouse model was generated by intraperitoneal injection of streptozotocin and then subjected to focal cerebral ischemia. We demonstrated that the DPP-4 inhibitor linagliptin significantly decreased the infarct volume, reduced neuronal cell death, decreased inflammation, and improved neurological deficit compared with control mice. Linagliptin up-regulated the expression of p-Akt and p-mTOR and regulated the apoptosis factors Bcl-2, Bax, and caspase 9. Taken together, these results suggest that linagliptin exerts a neuroprotective action likely through activation of the Akt/mTOR pathway along with anti-apoptotic and anti-inflammatory mechanisms. Therefore, linagliptin may be considered as a therapeutic treatment for stroke patients with mild hyperglycemia.

Endothelin-1-Induced Ischemic Damage and Functional Impairment Is Mediated Primarily by NR2B-Containing NMDA Receptors

Ischemic stroke accounts for 70-80% of stroke cases worldwide and survivors are frequently left with compromising sensorimotor deficits localized to one or more body regions. Most animal models of stroke involve transient or permanent occlusion of one or more major vessels such as the middle cerebral artery and are characterized by widespread damage to cortical and subcortical structures that result in deficits that can confound studies of neuroprotection and neurorehabilitation. Localized microinjections of the vasoconstricting peptide endothelin-1 (ET-1) into specific brain regions are becoming increasingly popular for such studies, but the pharmacology of endothelin-induced ischemic damage is poorly understood. To test the hypothesis that NMDA receptors, and particularly those containing the NR2B subunit, are involved in ET-1-mediated excitotoxicity and functional impairment, male CD1 rats (N = 32) were pre-treated with either the non-competitive NMDA antagonist MK-801 or the NR2B-selective antagonist Ro25-6981 (or vehicle) prior to unilateral microinjections of endothelin-1 into the somatosensory cortex and striatum. Rats were then tested using 4 established tests of sensory and/or motor function over 14 days. Lesion volumes were quantified post-mortem using standard histology and image analysis. Results confirmed reproducible lesions and significant deficits in all tests in vehicle-treated rats that were significantly reduced in both drug groups but were not different between drugs, providing evidence that endothelin-induced ischemic damage is mediated almost exclusively by NR2B-containing NMDA receptors.

Modulator of apoptosis-1 is a potential therapeutic target in acute ischemic injury

Modulator of apoptosis 1 (MOAP-1) is a Bax-associating protein highly enriched in the brain. In this study, we examined the role of MOAP-1 in promoting ischemic injuries following a stroke by investigating the consequences of MOAP-1 overexpression or deficiency in in vitro and in vivo models of ischemic stroke. MOAP-1 overexpressing SH-SY5Y cells showed significantly lower cell viability following oxygen and glucose deprivation (OGD) treatment when compared to control cells. Consistently, MOAP-1^-/- primary cortical neurons were observed to be more resistant against OGD treatment than the MOAP-1^+/+ primary neurons. In the mouse transient middle cerebral artery occlusion (tMCAO) model, ischemia triggered MOAP-1/Bax association, suggested activation of the MOAP-1-dependent apoptotic cascade. MOAP-1^-/- mice were found to exhibit reduced neuronal loss and smaller infarct volume 24 h after tMCAO when compared to MOAP-1^+/+ mice. Correspondingly, MOAP-1^-/- mice also showed better integrity of neurological functions as demonstrated by their performance in the rotarod test. Therefore, both in vitro and in vivo data presented strongly support the conclusion that MOAP-1 is an important apoptotic modulator in ischemic injury. These results may suggest that a reduction of MOAP-1 function in the brain could be a potential therapeutic approach in the treatment of acute stroke.

Biochanin A Provides Neuroprotection Against Cerebral Ischemia/Reperfusion Injury by Nrf2-Mediated Inhibition of Oxidative Stress and Inflammation Signaling Pathway in Rats

Background

Oxidative stress and neuroinflammation are 2 pivotal mechanisms in the progression of cerebral ischemia/reperfusion injury. Biochanin A, a natural phytoestrogen, has been reported to protect against ischemic brain injury in animal experiments, but the possible pharmacological mechanisms of its neuroprotection remain elusive. In this research, we sought to investigate the neuroprotective effects of biochanin A in experimental stroke rats and the probable mechanisms underlying oxidative stress and inflammation signaling pathways.

Material/Methods

An ischemic stroke model was induced by inserting thread into the middle cerebral artery. Rats were pre-administered intraperitoneally with a vehicle solution or biochanin A (10, 20, or 40 mg·kg·d⁻¹) for 14 days prior to ischemic stroke. Neurological score, infarct volume, and cerebral edema were assessed after 2 h of ischemia and 24 h of reperfusion. The activities of SOD and GSH-Px and MDA content were measured. The expressions of Nrf2, HO-1, and NF-κB and the activity of phosphor-IκBα were detected by Western blotting.

Results

Biochanin A pretreatment significantly improved neurological deficit and decreased infarct size and brain edema. Biochanin A also enhanced SOD and GSH-Px activities and suppressed the production of MDA. Additionally, biochanin A promoted Nrf2 nuclear translocation, promoted the expression of HO-1, and inhibited NF-κB activation in ischemic brain injury.

Conclusions

The results indicated that biochanin A protected the brain against ischemic injury in rats by anti-oxidative and anti-inflammatory actions. The activation of the Nrf2 pathway and the inhibition of the NF-κB pathway may contribute to the neuroprotective effects of biochanin A.

Brain-Derived Microparticles (BDMPs) Contribute to Neuroinflammation and Lactadherin Reduces BDMP Induced Neuroinflammation and Improves Outcome After Stroke

Microparticles (MPs, ~size between 0.1 and 1 mm) are lipid encased containers derived from intact cells which contain antigen from the parent cells. MPs are involved in intercellular communication and regulate inflammation. Stroke increases secretion of brain derived MP (BDMP) which activate macrophages/microglia and induce neuroinflammation. Lactadherin (Milk fat globule–EGF factor-8) binds to anionic phospholipids and extracellular matrices, promotes apoptotic cell clearance and limits pathogenic antigen cross presentation. In this study, we investigate whether BDMP affects stroke-induced neuroinflammation and whether Lactadherin treatment reduces stroke initiated BDMP-induced neuroinflammation, thereby improving functional outcome after stroke. Middle aged (8–9 months old) male C57BL/6J mice were subjected to distal middle cerebral artery occlusion (dMCAo) stroke, and BDMPs were extracted from ischemic brain 24 h after dMCAo by ultracentrifugation. Adult male C57BL/6J mice were subjected to dMCAo and treated via tail vein injection at 3 h after stroke with: (A) +PBS (n = 5/group); (B) +BDMPs (1.5 × 10⁸, n = 6/group); (C) +Lactadherin (400 μg/kg, n = 5/group); (D) +BDMP+Lactadherin (n = 6/group). A battery of neurological function tests were performed and mice sacrificed for immunostaining at 14 days after stroke. Blood plasma was used for Western blot assay. Our data indicate: (1) treatment of Stroke with BDMP significantly increases lesion volume, neurological deficits, blood brain barrier (BBB) leakage, microglial activation, inflammatory cell infiltration (CD45, microglia/macrophages, and neutrophils) into brain, inflammatory factor (TNFα, IL6, and IL1β) expression in brain, increases axon/white matter (WM) damage identified by decreased axon and myelin density, and increases inflammatory factor expression in the plasma when compared to PBS treated stroke mice; (2) when compared to PBS and BDMP treated stroke mice, Lactadherin and BDMP+Lactadherin treatment significantly improves neurological outcome, and decreases lesion volume, BBB leakage, axon/WM injury, inflammatory cell infiltration and inflammatory factor expression in the ischemic brain, respectively. Lactadherin treatment significantly increases anti-inflammatory factor (IL10) expression in ischemic brain and decreases IL1β expression in plasma compared to PBS and BDMP treated stroke mice, respectively. BDMP increases neuroinflammation and aggravates ischemic brain damage after stroke. Thus, Lactadherin exerts anti-inflammatory effects and improves the clearance of MPs to reduce stroke and BDMP induced neurological deficits.

Pharmacological hypothermia induced neurovascular protection after severe stroke of transient middle cerebral artery occlusion in mice

Therapeutic hypothermia is a potential protective strategy after stroke. The present study evaluated the neurovascular protective potential of pharmacological hypothermia induced by the neurotensin receptor 1 agonist HPI-201 after severe ischemic stroke. Adult C57BL/6 mice were subjected to filament insertion-induced occlusion of the middle cerebral artery (60 min MCAO). HPI-201 was i.p. injected 120 min after the onset of MCAO to initiate and maintain the body temperature at 32-33°C for 6 hrs. The infarct volume, cell death, integrity of the blood brain barrier (BBB) and neurovascular unit (NVU), inflammation, and functional outcomes were evaluated. The hypothermic treatment significantly suppressed the infarct volume and neuronal cell death, accompanied with reduced caspase-3 activation and BAX expression while Bcl-2 increased in the peri-infarct region. The cellular integrity of the BBB and NVU was significantly improved and brain edema was attenuated in HPI-201-treated mice compared to stroke controls. The hypothermic treatment decreased the expression of inflammatory factors including tumor necrosis factor-α (TNF-α), MMP-9, interleukin-1β (IL-1β), the M1 microglia markers IL-12 and inducible nitric oxide synthase (iNOS), while increased the M2 marker arginase-1 (Arg-1). Stroke mice received the hypothermic treatment showed lower neurological severity score (NSS), performed significantly better in functional tests, the mortality rate in the hypothermic group was noticeably lower compared with stroke controls. Taken together, HPI-201 induced pharmacological hypothermia is protective for different neurovascular cells after a severely injured brain, mediated by multiple mechanisms.

Iridoid glycosides from Radix Scrophulariae attenuates focal cerebral ischemia‑reperfusion injury via inhibiting endoplasmic reticulum stress‑mediated neuronal apoptosis in rats

Iridoid glycosides of Radix Scrophulariae (IGRS) are a group of the major bioactive components from Radix Scrophulariae with extensive pharmacological activities. The present study investigated the effects of IGRS on cerebral ischemia‑reperfusion injury (CIRI) and explored its potential mechanisms of action. A CIRI model in rats was established by occlusion of the right middle cerebral artery for 90 min, followed by 24 h of reperfusion. Prior to surgery, 30, 60 or 120 mg/kg IGRS was administered to the rats once a day for 7 days. Then, the neurological scores, brain edema and volume of the cerebral infarction were measured. The apoptosis index was determined by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling. The effects of IGRS on the histopathology of the cortex in brain tissues and the endoplasmic reticulum ultrastructure in the hippocampus were analyzed. Finally, the expression of endoplasmic reticulum stress (ERS)‑regulating mediators, endoplasmic reticulum chaperone BiP (GRP78), DNA damage‑inducible transcript 3 protein (CHOP) and caspase‑12, were detected by reverse transcription quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. The volume of cerebral infarction and brain water content in the IGRS‑treated groups treated at doses of 60 and 120 mg/kg were decreased significantly compared with the Model group. The neurological scores were also significantly decreased in the IGRS‑treated groups. IGRS treatment effectively decreased neuronal apoptosis resulting from CIRI‑induced neuron injury. In addition, the histopathological damage and the endoplasmic reticulum ultrastructure injury were partially improved in CIRI rats following IGRS treatment. RT‑qPCR and western blot analysis data indicated that IGRS significantly decreased the expression levels of GRP78, CHOP and caspase‑12 at both mRNA and protein levels. The results of the present study demonstrated that IGRS exerted a protective effect against CIRI in brain tissue via the inhibition of apoptosis and ERS.

ApoA-I Mimetic Peptide Reduces Vascular and White Matter Damage After Stroke in Type-2 Diabetic Mice

Diabetes leads to an elevated risk of stroke and worse functional outcome compared to the general population. We investigate whether L-4F, an economical ApoA-I mimetic peptide, reduces neurovascular and white-matter damage in db/db type-2 diabetic (T2DM) stroke mice. L-4F (16 mg/kg, subcutaneously administered initially 2 h after stroke and subsequently daily for 4 days) reduced hemorrhagic transformation, decreased infarct-volume and mortality, and treated mice exhibited increased cerebral arteriole diameter and smooth muscle cell number, decreased blood-brain barrier leakage and white-matter damage in the ischemic brain as well as improved neurological functional outcome after stroke compared with vehicle-control T2DM mice (p < 0.05, n = 11/group). Moreover, administration of L-4F mitigated macrophage infiltration, and reduced the level of proinflammatory mediators tumor necrosis factor alpha (TNFα), high-mobility group box-1 (HMGB-1)/advanced glycation end-product receptor (RAGE) and plasminogen activator inhibitor-1 (PAI-1) in the ischemic brain in T2DM mice (p < 0.05, n = 6/group). In vitro, L-4F treatment did not increase capillary-like tube formation in mouse-brain endothelial cells, but increased primary artery explant cell migration derived from C57BL/6-aorta 1 day after middle cerebral artery occlusion (MCAo), and enhanced neurite-outgrowth after 2 h of oxygen-glucose deprivation and axonal-outgrowth in primary cortical neurons derived from the C57BL/6-embryos subjected to high-glucose condition. This study suggests that early treatment with L-4F provides a potential strategy to reduce neuroinflammation and vascular and white-matter damage in the T2DM stroke population.

Remarkable cell recovery from cerebral ischemia in rats using an adaptive escalator-based rehabilitation mechanism

Currently, many ischemic stroke patients worldwide suffer from physical and mental impairments, and thus have a low quality of life. However, although rehabilitation is acknowledged as an effective way to recover patients’ health, there does not exist yet an adaptive training platform for animal tests so far. For this sake, this paper aims to develop an adaptive escalator (AE) for rehabilitation of rats with cerebral ischemia. Rats were observed to climb upward spontaneously, and a motor-driven escalator, equipped with a position detection feature and an acceleration/deceleration mechanism, was constructed accordingly as an adaptive training platform. The rehabilitation performance was subsequently rated using an incline test, a rotarod test, the infarction volume, the lesion volume, the number of MAP2 positive cells and the level of cortisol. This paper is presented in 3 parts as follows. Part 1 refers to the escalator mechanism design, part 2 describes the adaptive ladder-climbing rehabilitation mechanism, and part 3 discusses the validation of an ischemic stroke model. As it turned out, a rehabilitated group using this training platform, designated as the AE group, significantly outperformed a control counterpart in terms of a rotarod test. After the sacrifice of the rats, the AE group gave an average infarction volume of (34.36 ± 3.8)%, while the control group gave (66.41 ± 3.1)%, validating the outperformance of the escalator-based rehabilitation platform in a sense. An obvious difference between the presented training platform and conventional counterparts is the platform mechanism, and for the first time in the literature rats can be well and voluntarily rehabilitated at full capacity using an adaptive escalator. Taking into account the physical diversity among rats, the training strength provided was made adaptive as a reliable way to eliminate workout or secondary injury. Accordingly, more convincing arguments can be made using this mental stress-free training platform.

The effect of chronic cerebral hypoperfusion on the pathology of Alzheimer's disease: A positron emission tomography study in rats

Cerebrovascular disease is a potential risk factor for Alzheimer's disease (AD). Although acute cerebral hypoperfusion causes neuronal necrosis and infarction, chronic cerebral hypoperfusion induces apoptosis in neurons, but its effects on the cognitive impairment are not clear. The purpose of this study was to evaluate the effects of chronic cerebral hypoperfusion on AD pathology and cerebral glucose metabolism. A model of chronic cerebral hypoperfusion was established by ligating the common carotid arteries bilaterally in adult male rats (CAL group). Sham-operated rats underwent the same procedures without artery ligation (control group). At 12 weeks after ligation, expression levels of amyloid-β (Aβ) and hyperphosphorylated tau (p-tau), as well as the regional cerebral glucose metabolism, were evaluated using Western blots and positron emission tomography with fluorine-18 fluorodeoxyglucose, respectively. The expression levels of Aβ in the frontal cortex and hippocampus and of p-tau in the temporal cortex were significantly higher in the CAL group than those in the control group. The cerebral glucose metabolism of the amygdala, entorhinal cortex, and hippocampus was significantly decreased in the CAL group compared to that in the control. These results suggest that chronic cerebral hypoperfusion can induce AD pathology and may play a significant role in AD development.

Intravenous Immunoglobulin (IVIg) Induce a Protective Phenotype in Microglia Preventing Neuronal Cell Death in Ischaemic Stroke

Targeting the immune system and thereby modulating the inflammatory response in ischemic stroke has shown promising therapeutic potential in various preclinical trials. Among those, intravenous immunoglobulins (IVIg) have moved into the focus of attention. In a murine model of experimental stroke, we explored the therapeutic potential of IVIg on the neurological outcome and the inflammatory response. Further, we used an in vitro system to assess effects of IVIg-stimulated microglia on neuronal survival. Treatment with IVIg resulted in decreased lesion sizes, without significant effects on the infiltration and activation pattern of peripheral immune cells. However, in microglia IVIg induced a switch towards an upregulation of protective polarization markers, and the ablation of microglia led to the loss of neuroprotective IVIg effects. Functionally, IVIg stimulated microglia ameliorated neuronal cell death elicited by oxygen and glucose deprivation in vitro. Notably, application of IVIg in vivo led to a comparable decrease of apoptotic neurons in the penumbra area. Although neuroprotective effects of IVIg in vivo and in vitro have been established in previous studies, we were able to show for the first time, that IVIg modulates the polarization of microglia during the pathogenesis of stroke.

The Beneficial Effects of Raffinee in Permanent Occulted Stroke Mice

Ischemic stroke is a major cause of disability and mortality globally. Although thrombolytic therapy is routinely adopted in cases of ischemic stroke, various alternative natural neuroprotectants are also used as effective adjuvant therapies to recover neurofunction following ischemic stroke. Raffinee, a natural fermented product with strong antioxidant and neuroprotective activities, has antiatherogenic effects in animals and has exhibited neuroprotective effects in a clinical trial by recovering motor and sensory function following spinal cord lesion. This study reveals the advantageous effects of Raffinee on PC12 cells by decreasing hypoxia-induced apoptosis in mice with permanent middle cerebral artery occlusion (pMCAO) by increasing the levels of neurotrophic factors such as S100β, reducing serum inflammatory factors such as matrix metalloproteinases (MMP)-9/MMP-2 ratio, tumor necrosis factor-α, and interleukin (IL)-6 level, and increasing IL-10 levels. Significantly reduced brain infarct volume along with a favorable survival ratio was observed for pMCAO mice that received Raffinee, suggesting a neuroprotective potential of Raffinee in cases of acute ischemic stroke by suppressing apoptosis.

A Single Injection of Docosahexaenoic Acid Induces a Pro-Resolving Lipid Mediator Profile in the Injured Tissue and a Long-Lasting Reduction in Neurological Deficit after Traumatic Brain Injury in Mice

Traumatic brain injury (TBI) can lead to life-changing neurological deficits, which reflect the fast-evolving secondary injury post-trauma. There is a need for acute protective interventions, and the aim of this study was to explore in an experimental TBI model the neuroprotective potential of a single bolus of a neuroactive omega-3 fatty acid, docosahexaenoic acid (DHA), administered in a time window feasible for emergency services. Adult mice received a controlled cortical impact injury (CCI) and neurological impairment was assessed with the modified Neurological Severity Score (mNSS) up to 28 days post-injury. DHA (500 nmol/kg) or saline were injected intravenously at 30 min post-injury. The lipid mediator profile was assessed in the injured hemisphere at 3 h post-CCI. After completion of behavioral tests and lesion assessment using magnetic resonance imaging, over 7 days or 28 days post-TBI, the tissue was analyzed by immunohistochemistry. The single DHA bolus significantly reduced the injury-induced neurological deficit and increased pro-resolving mediators in the injured brain. DHA significantly reduced lesion size, the microglia and astrocytic reaction, and oxidation, and decreased the accumulation of beta-amyloid precursor protein (APP), indicating a reduced axonal injury at 7 days post-TBI. DHA reduced the neurofilament light levels in plasma at 28 days. Therefore, an acute single bolus of DHA post-TBI, in a time window relevant for acute emergency intervention, can induce a long-lasting and significant improvement in neurological outcome, and this is accompanied by a marked upregulation of neuroprotective mediators, including the DHA-derived resolvins and protectins.

Involvement of d-amino acid oxidase in cerebral ischaemia induced by transient occlusion of the middle cerebral artery in mice

BACKGROUND AND PURPOSE

d-Amino acid oxidase (DAAO) is a flavine adenine dinucleotide-containing flavoenzyme and specifically catalyses oxidative deamination of d-amino acids. This study aimed to explore the association between increased cerebral DAAO expression or enzymic activity and the development of cerebral ischaemia.

EXPERIMENTAL APPROACH

A mouse model of transient (90 min) middle cerebral artery occlusion (MCAO) was established, and western blotting, enzymic activity assay, and fluorescent immunostaining techniques were used.

KEY RESULTS

The expression and enzymic activity of DAAO increased over time in the cortical peri-infarct area of the mice subjected to transient MCAO. The DAAO was specifically expressed in astrocytes, and its double immunostaining with the astrocytic intracellular marker, glial fibrillary acidic protein, in the cortical peri-infarct area was up-regulated following ischaemic insult, with peak increase on Day 5 after MCAO. Single intravenous injection of the specific and potent DAAO inhibitor Compound SUN reduced the cerebral DAAO enzymic activity and attenuated neuronal infarction and neurobehavioural deficits with optimal improvement apparent immediately after the MCAO procedure. The neuroprotective effect was dose dependent, with ED50 values of 3.9-4.5 mg·kg-1 . Intracerebroventricular injection of the DAAO gene silencer siRNA/DAAO significantly reduced cerebral DAAO expression and attenuated MCAO-induced neuronal infarction and behavioural deficits.

CONCLUSIONS AND IMPLICATIONS

Our results, for the first time, demonstrated that increased cerebral astrocytic DAAO expression and enzymic activity were causally associated with the development of neuronal destruction following ischaemic insults, suggesting that targeting cerebral DAAO could be a potential approach for treatment of neurological conditions following cerebral ischaemia.

Inhibition of PI3Kγ by AS605240 Protects tMCAO Mice by Attenuating Pro-Inflammatory Signaling and Cytokine Release in Reactive Astrocytes

The intense and prolonged inflammatory response after ischemic stroke significantly contributes to the secondary neural injury. PI3Kγ, which is involved in the regulation of vascular permeability, chemotactic leukocyte migration and microglia activation, is a key target for intervention in the inflammatory response. In this study, we identified the protective effect of the PI3Kγ inhibitor AS605240 against stroke-related injury in the mouse model of transient intraluminal middle cerebral artery occlusion (tMCAO). The results showed that administration of AS605240 could improve the neurological function score, reduce the infarct size and decrease astrocyte activation in the tMCAO mice after injury. The inhibitory effect of AS605240 on microglia activation is relatively clear. Therefore, in this study, the effects of AS605240 on astrocytes were studied in cell cultures. IL-6 and its soluble receptor were used to construct the astrocyte activation model. AS605240 treatment significantly reduced the astrocyte activation markers and the morphological changes of cells. We also identified 13 inflammatory factors whose expression was significantly upregulated by IL-6/sIL-6R and significantly inhibited by AS605240 at the protein level, and seven of those factors were verified at the mRNA level. These results indicated that specific inhibition of PI3Kγ could reduce astrocyte activation induced by inflammation, which might aid the repair and remodeling of neurons in the later stage after ischemic stroke.

Inhibition of T cell immunoglobulin and mucin-1 (TIM-1) protects against cerebral ischemia-reperfusion injury

Background

The T cell Ig domain and mucin domain (TIM)-1 protein expressed on the surface of Th2 cells regulates the immune response by modulating cytokine production. The present study aimed to investigate the role and possible mechanism of TIM-1 in cerebral ischemia-reperfusion injury.

Methods

Western blot was used to detect TIM-1 and apoptosis-related protein expression, whereas TIM-1 mRNA was examined using quantitative real-time reverse transcription PCR. Flow cytometry and a TdT-mediated biotin-16-dUTP nick-end labeling (TUNEL) assay were used to detect the percentage of apoptotic cells and a pathological examination was performed. The migration of neutrophils and macrophages was analyzed by immunohistochemistry.

Results

Our results suggest that TIM-1 expression was transiently increased 24 h or 48 h following middle cerebral artery occlusion (MCAO)/reperfusion. The infarct size was markedly increased in MCAO, whereas treatment with a TIM-1-blocking mAb could reduce the infarct size. TIM-1 blocking mAb effectively reduced the number of neutrophils, macrophage functionality, cytokine (i.e., IL-6, IL-1β, and TNF-α) and chemokine (i.e., CXCL-1 and CXCL-2) production in the brain tissue. The effect of in vitro T cell damage on neurons was significantly reduced following treatment with a TIM-1 blocking mAb or the knockdown of TIM-1 in co-cultured T cells and neurons.

Conclusion

Take together, these results indicated that TIM-1 blockade ameliorated cerebral ischemia-reperfusion injury. Thus, TIM-1 disruption may serve as a novel target for therapy following MCAO.