Neuroprotective Effect of Atorvastatin Involves Suppression of TNF-α and Upregulation of IL-10 in a Rat Model of Intracerebral Hemorrhage

We evaluated the neuroprotective effects of atorvastatin (2, 5, and 10 mg/kg) on experimentally induced intracerebral hemorrhage (ICH) in adult rats; controls were administered PBS. Plasma TNF-α and IL-10 levels before and after ICH were analyzed at various time points by enzyme-linked immunosorbent assay (ELISA) and neurological behavior of rats was assessed by climbing scores. At 3-days postoperatively, brain water contents and TNF-α/IL-10 expression in brain tissue were determined. Histopathological changes and microglial cells in the brain tissue were evaluated by light-microscopy. Post-ICH neurological deficits differed significantly between sham-operated group A and experimental-ICH group B (P < 0.05). Brain water contents were significantly less in group A than in group B (P < 0.05). Significant differences (P < 0.05) between two groups were observed regarding activated microglia, TNF-α and IL-10 levels. Compared with group B, neurological deficits, brain water contents, pathological changes, and activated microglia were reduced (P < 0.05) in groups C (Experimental-ICH + atorvastatin 2 mg/kg), D (Experimental-ICH + atorvastatin 5 mg/kg) and E (Experimental-ICH + atorvastatin 10 mg/kg). Atorvastatin-induced a dose-dependent reduction of TNF-α and increase of IL-10 levels (P < 0.05). Therefore, it was concluded that atorvastatin improved neurofunctional rehabilitation in rats through the suppression of cytokines-mediated inflammatory response and attenuation of brain damage following intracerebral hemorrhage.     

Metformin Attenuates Neurological Deficit after Intracerebral Hemorrhage by Inhibiting Apoptosis,Oxidative Stress and Neuroinflammation in Rats

Intracerebral hemorrhage (ICH) can lead to brain damage and even death, and there is lack of effective therapeutic methods for treating ICH. Although recent studies have focused on the administration of metformin in treating stroke, there is no literature to support whether it can be used to treat ICH. Therefore, the aim of this study was to evaluate the possible effects of metformin on ICH and the underlying mechanisms of those effects. An ICH model was established in adult male Sprague–Dawley rats. Rats were randomly divided into three groups: sham group, ICH group, and ICH+metformin group. The neurobehavioral deficit scoring method was used to examine neurological function in rats. The levels of lipid peroxidation antioxidant enzyme and 8-iso-PGF2α were detected to evaluate oxidative stress. Survival of striatal neurons was examined by TUNEL staining, immunohistochemistry and HE staining. The levels of p-JNK, p-c-Jun and cleaved caspase-3 in the striatum were measured by western blotting. The results demonstrated that metformin protected rats from neurological deficits induced by ICH. Moreover, metformin reduced oxidative stress and preserved the survival of striatal neurons under ICH conditions. Furthermore, metformin downregulated the levels of apoptotic factors (p-JNK3, p-c-Jun and cleaved caspase-3) as well as pro-inflammatory cytokines (IL-1β, IL-4 and IL-6 and TNF-α). Collectively, we speculate that metformin may be a potential clinical treatment for ICH patients.

     

Adoptive Regulatory T-cell Therapy Attenuates Perihematomal Inflammation in a Mouse Model of Experimental Intracerebral Hemorrhage

The CD4⁺CD25⁺ regulatory T cells (Tregs), an innate immunomodulator, suppress cerebral inflammation and maintain immune homeostasis in multiple central nervous system injury, but its role in intracerebral hemorrhage (ICH) has not been fully characterized. This study investigated the effect of Tregs on brain injury using the mouse ICH model, which is established by autologous blood infusion. The results showed that tail intravenous injection of Tregs significantly reduced brain water content and Evans blue dye extravasation of perihematoma at day (1, 3 and 7), and improved short- and long-term neurological deficits following ICH in mouse model. Tregs treatment reduced the content of pro-inflammatory cytokines interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and malondialdehyde, while increasing the superoxide dismutase (SOD) enzymatic activity at day (1, 3 and 7) following ICH. Furthermore, Tregs treatment obviously reduced the number of NF-κB⁺, IL-6⁺, TUNEL⁺ and active caspase-3⁺ cells at day 3 after ICH. These results indicate that adoptive transfer of Tregs may provide neuroprotection following ICH in mouse models.     

Mechanisms of transformation of nicotinamide mononucleotides to cerebral infarction hemorrhage based on MCAO model

ObjectiveThe study aims at discussing the effect of nicotinamide mononucleotides on protecting hemorrhagic transformation of cerebral infarction in the middle cerebral artery occlusion (MCAO) model.MethodMale mice aged 4–5 weeks and weighing about 22–35 g in Shanghai Ninth People’s Hospital are divided into three groups: sham group, collagenase intracerebral hemorrhage model (cICH + Vehicle) group and collagenase nicotinamide mononucleotide (cICH + NMN) group. Then, the intervention therapy research is carried out. After 24 h, the neurological function, brain edema, hematoma volume, body weight, hemorrhage volume, RNA expression level, apoptosis, inflammatory factors and reactive oxygen species (ROS) content in surrounding tissues of mice are analyzed comprehensively.ResultsCompared with the other two groups, nicotinamide mononucleotides in MCAO model have significant effects on improving neurological function, brain edema, inflammatory factors, body weight and cell apoptosis in mice, but have no significant effect on hemorrhage volume and hematoma volume in mice.ConclusionNicotinamide mononucleotides can significantly improve the collagenase-induced intracerebral hemorrhage (ICH) model in mice under MCAO model, and they can protect the brain tissue of mice from RNA level to tissue cell level or mouse body weight and volume level.     

Umbilical cord-derived MSC and hyperbaric oxygen therapy effectively protected the brain in rat after acute intracerebral haemorrhage

This study tested the hypothesis that combined therapy with human umbilical cord-derived mesenchymal stem cells (HUCDMSCs) and hyperbaric oxygen (HBO) was superior to either one on preserving neurological function and reducing brain haemorrhagic volume (BHV) in rat after acute intracerebral haemorrhage (ICH) induced by intracranial injection of collagenase. Adult male SD rats (n = 30) were equally divided into group 1 (sham-operated control), group 2 (ICH), group 3 (ICH +HUCDMSCs/1.2 × 10⁶ cells/intravenous injection at 3h and days 1 and 2 after ICH), group 4 (ICH +HBO/at 3 hours and days 1 and 2 after ICH) and group 5 (ICH +HUCDMSCs-HBO), and killed by day 28 after ICH. By day 1, the neurological function was significantly impaired in groups 2-5 than in group 1 (P < .001), but it did not differ among groups 2 to 5. By days 7, 14 and 28, the integrity of neurological function was highest in group 1, lowest in group 2 and significantly progressively improved from groups 3 to 5 (all P < .001). By day 28, the BHV was lowest in group 1, highest in group 2 and significantly lower in group 5 than in groups 3/4 (all P < .0001). The protein expressions of inflammation (HMGB1/TLR-2/TLR-4/MyD88/TRAF6/p-NF-κB/IFN-γ/IL-1ß/TNF-α), oxidative stress/autophagy (NOX-1/NOX-2/oxidized protein/ratio of LC3B-II/LC3B-I) and apoptosis (cleaved-capspase3/PARP), and cellular expressions of inflammation (CD14+, F4/80+) in brain tissues exhibited an identical pattern, whereas cellular levels of angiogenesis (CD31+/vWF+/small-vessel number) and number of neurons (NeuN+) exhibited an opposite pattern of BHV among the groups (all P < .0001). These results indicate that combined HUCDMSC-HBO therapy offered better outcomes after rat ICH.     

Modeling Intracerebral Hemorrhage in Mice: Injection of Autologous Blood or Bacterial Collagenase

Spontaneous intracerebral hemorrhage (ICH) defines a potentially life-threatening neurological malady that accounts for 10-15% of all stroke-related hospitalizations and for which no effective treatments are available to date^1,2. Because of the heterogeneity of ICH in humans, various preclinical models are needed to thoroughly explore prospective therapeutic strategies³. Experimental ICH is commonly induced in rodents by intraparenchymal injection of either autologous blood or bacterial collagenase⁴. The appropriate model is selected based on the pathophysiology of hemorrhage induction and injury progression. The blood injection model mimics a rapidly progressing hemorrhage. Alternatively, bacterial collagenase enzymatically disrupts the basal lamina of brain capillaries, causing an active bleed that generally evolves over several hours⁵. Resultant perihematomal edema and neurofunctional deficits can be quantified from both models. In this study, we described and evaluated a modified double injection model of autologous whole blood⁶ as well as an ICH injection model of bacterial collagenase⁷, both of which target the basal ganglia (corpus striatum) of male CD-1 mice. We assessed neurofunctional deficits and brain edema at 24 and 72 hr after ICH induction. Intrastriatal injection of autologous blood (30 μl) or bacterial collagenase (0.075U) caused reproducible neurofunctional deficits in mice and significantly increased brain edema at 24 and 72 hr after surgery (p<0.05). In conclusion, both models yield consistent hemorrhagic infarcts and represent basic methods for preclinical ICH research.     

Attenuation of Acute Phase Injury in Rat Intracranial Hemorrhage by Cerebrolysin that Inhibits Brain Edema and Inflammatory Response

The outcome of intracerebral hemorrhage (ICH) is mainly determined by the volume of the hemorrhage core and the secondary brain damage to penumbral tissues due to brain swelling, microcirculation disturbance and inflammation. The present study aims to investigate the protective effects of cerebrolysin on brain edema and inhibition of the inflammation response surrounding the hematoma core in the acute stage after ICH. The ICH model was induced by administration of type VII bacterial collagenase into the stratum of adult rats, which were then randomly divided into three groups: ICH + saline; ICH + Cerebrolysin (5 ml/kg) and sham. Cerebrolysin or saline was administered intraperitoneally 1 h post surgery. Neurological scores, extent of brain edema content and Evans blue dye extravasation were recorded. The levels of pro-inflammatory factors (IL-1β, TNF-α and IL-6) were assayed by Real-time PCR and Elisa kits. Aquaporin-4 (AQP4) and tight junction proteins (TJPs; claudin-5, occludin and zonula occluden-1) expression were measured at multiple time points. The morphological and intercellular changes were characterized by Electron microscopy. It is found that cerebrolysin (5 ml/kg) improved the neurological behavior and reduced the ipsilateral brain water content and Evans blue dye extravasation. After cerebrolysin treated, the levels of pro-inflammatory factors and AQP4 in the peri-hematomal areas were markedly reduced and were accompanied with higher expression of TJPs. Electron microscopy showed the astrocytic swelling and concentrated chromatin in the ICH group and confirmed the cell junction changes. Thus, early cerebrolysin treatment ameliorates secondary injury after ICH and promotes behavioral performance during the acute phase by reducing brain edema, inflammatory response, and blood–brain barrier permeability.     

Enhanced Neuroprotection of Minimally Invasive Surgery Joint Local Cooling Lavage against ICH-induced Inflammation Injury and Apoptosis in Rats

Hypothermia treatment is one of the neuroprotective strategies that improve neurological outcomes effectively after brain damage. Minimally invasive surgery (MIS) has been an important treatment of intracerebral hemorrhage (ICH). Herein, we evaluated the neuroprotective effect and mechanism of MIS joint local cooling lavage (LCL) treatment on ICH via detecting the inflammatory responses, oxidative injury, and neuronal apoptosis around the hematoma cavity in rats. ICH model was established by type IV collagenase caudatum infusion. The rats were treated with MIS 6 h after injection, and then were lavaged by normothermic (37 °C) and hypothermic (33 °C) normal saline in brain separately. The results indicated that MIS joint LCL treatment showed enhanced therapeutic effects against ICH-induced inflammation injury and apoptosis in rats, as convinced by the decline of TUNEL-positive cells, followed by the decrease of IL-1β and LDH and increase of IL-10 and SOD. This study demonstrated that the strategy of using MIS joint LCL may achieve enhanced neuroprotection against ICH-induced inflammation injury and apoptosis in rats with potential clinic application.     

Increased IL-8 levels in HIV-infected individuals who initiated ART with CD4+ T cell counts <350 cells/mm3 – A potential hallmark of chronic inflammation

The identification of inflammatory markers in HIV+ individuals on ART is fundamental since chronic ART-controlled HIV infection is linked to an increased inflammatory state. In this context, we assessed plasma levels of pro-inflammatory cytokines (IL-1β, IL-8, and IL-12p70) of HIV+ individuals who initiated ART after immunosuppression (CD4⁺ T cell counts <350 cells/mm³). HIV+ individuals were stratified according to two extreme phenotypes: Slow Progressors (SPs; individuals with at least 8 years of infection before ART initiation) and Rapid Progressors (RPs; individuals who needed to initiate ART within 1–4 years after infection). A control group was composed of HIV-uninfected individuals. We found increased IL-8 levels (median: 5.13 pg/mL; SPs and RPs together) in HIV-infected individuals on ART as compared to controls (median: 3.2 pg/mL; p = 0.04), although no association with the progression profile (slow or rapid progressors) or CD4⁺ T cell counts at sampling was observed. This result indicates that IL-8 is a general marker of chronic inflammation in HIV+ individuals on ART, independently of CD4⁺ T cell counts at the beginning of the treatment or of the potential progression profile of the patient. In this sense, IL-8 may be considered a possible target for novel therapies focused on reducing inflammation in chronic HIV infection.     

Protection of Vascular Endothelial Growth Factor to Brain Edema Following Intracerebral Hemorrhage and Its Involved Mechanisms: Effect of Aquaporin-4

Vascular endothelial growth factor (VEGF) has protective effects on many neurological diseases. However, whether VEGF acts on brain edema following intracerebral hemorrhage (ICH) is largely unknown. Our previous study has shown aquaporin-4 (AQP4) plays an important role in brain edema elimination following ICH. Meanwhile, there is close relationship between VEGF and AQP4. In this study, we aimed to test effects of VEGF on brain edema following ICH and examine whether they were AQP4 dependent. Recombinant human VEGF165 (rhVEGF165) was injected intracerebroventricularly 1 d after ICH induced by microinjecting autologous whole blood into striatum. We detected perihemotomal AQP4 protein expression, then examined the effects of rhVEGF165 on perihemotomal brain edema at 1 d, 3 d, and 7 d after injection in wild type (AQP4^+/+) and AQP4 knock-out (AQP4^−/−) mice. Furthermore, we assessed the possible signal transduction pathways activated by VEGF to regulate AQP4 expression via astrocyte cultures. We found perihemotomal AQP4 protein expression was highly increased by rhVEGF165. RhVEGF165 alleviated perihemotomal brain edema in AQP4^+/+ mice at each time point, but had no effect on AQP4^−/− mice. Perihemotomal EB extravasation was increased by rhVEGF165 in AQP4^−/− mice, but not AQP4^+/+ mice. RhVEGF165 reduced neurological deficits and increased Nissl’s staining cells surrounding hemotoma in both types of mice and these effects were related to AQP4. RhVEGF165 up-regulated phospharylation of C-Jun amino-terminal kinase (p-JNK) and extracellular signal-regulated kinase (p-ERK) and AQP4 protein in cultured astrocytes. The latter was inhibited by JNK and ERK inhibitors. In conclusion, VEGF reduces neurological deficits, brain edema, and neuronal death surrounding hemotoma but has no influence on BBB permeability. These effects are closely related to AQP4 up-regulation, possibly through activating JNK and ERK pathways. The current study may present new insights to treatment of brain edema following ICH.     

Transplantation of Induced Pluripotent Stem Cells Alleviates Cerebral Inflammation and Neural Damage in Hemorrhagic Stroke

Background

Little is known about the effects of induced pluripotent stem cell (iPSC) treatment on acute cerebral inflammation and injuries after intracerebral hemorrhage (ICH), though they have shown promising therapeutic potentials in ischemic stoke.

Methods

An ICH model was established by stereotactic injection of collagenase VII into the left striatum of male Sprague-Dawley (SD) rats. Six hours later, ICH rats were randomly divided into two groups and received intracerebrally 10 μl of PBS with or without 1×10⁶ of iPSCs. Subsequently, neural function of all ICH rats was assessed at days 1, 3, 7, 14, 28 and 42 after ICH. Inflammatory cells, cytokines and neural apoptosis in the rats’ perihematomal regions, and brain water content were determined on day 2 or 3 post ICH. iPSC differentiation was determined on day 28 post ICH. Nissl⁺ cells and glial fibrillary acidic protein (GFAP)⁺ cells in the perihematoma and the survival rates of rats in two groups were determined on post-ICH day 42.

Results

Compared with control animals, iPSCs treatment not only improved neurological function and survival rate, but also resulted in fewer intracephalic infiltrations of neutrophils and microglia, along with decreased interleukin (IL)-1β, IL-6 and tumour necrosis factor-alpha (TNF-α), and increased IL-10 in the perihematomal tissues of ICH rats. Furthermore, brain oedema formation, apoptosis, injured neurons and glial scar formation were decreased in iPSCs-transplanted rats.

Conclusions

Our findings indicate that iPSCs transplantation attenuate cerebral inflammatory reactions and neural injuries after ICH, and suggests that multiple mechanisms including inflammation modulation, neuroprotection and functional recovery might be involved simultaneously in the therapeutic benefit of iPSC treatment against hemorrhagic stroke.     

Angiotensin II type-1 receptor antagonist attenuates LPS-induced acute lung injury

Angiotensin II is able to trigger inflammatory responses through an angiotensin II type 1 (AT1) receptor. The role of AT1 receptor in acute lung injury (ALI) is poorly understood. Mice were randomly divided into three groups (n = 40 each groups): NS group; LPS group (2 mg/kg LPS intratracheally); and LPS + ZD 7155 group, 10 mg/kg ZD 7155 (an AT1 receptor antagonist) intraperitoneally 30 min prior to LPS exposure. Samples from the lung were isolated and assayed for histopathology analyses or proinflammatory gene expressions, angiotensin II receptors expressions and nuclear factors activities. LPS exposure resulted in severe ALI, elevated levels of TNF-α and IL-1β mRNA expressions, and increased activities of NF-κB and activated protein (AP)-1. Upregulation of AT1 receptor and down-regulation of AT2 receptor were also observed after LPS challenge. Pretreatment with ZD 7155 significantly inhibited the increase of AT1 receptor expression and upregulated AT2 receptor expression. ZD 7155 also reduced the mRNA expression of TNF-α and IL-1β, inhibited the activation of NF-κB and AP-1, and improved lung histopathology. These findings suggest that antagonism of AT1 receptor inhibits the activation of NF-κB and AP-1 in the lung, which may mediate the release of TNF-α and IL-1β and contribute to LPS-induced ALI.     

Cyclooxygenase‐1 inhibition reduces amyloid pathology and improves memory deficits in a mouse model of Alzheimer's disease

Several epidemiological and preclinical studies suggest that non‐steroidal anti‐inflammatory drugs (NSAIDs), which inhibit cyclooxygenase (COX), reduce the risk of Alzheimer's disease (AD) and can lower β‐amyloid (Aβ) production and inhibit neuroinflammation. However, follow‐up clinical trials, mostly using selective cyclooxygenase (COX)‐2 inhibitors, failed to show any beneficial effect in AD patients with mild to severe cognitive deficits. Recent data indicated that COX‐1, classically viewed as the homeostatic isoform, is localized in microglia and is actively involved in brain injury induced by pro‐inflammatory stimuli including Aβ, lipopolysaccharide, and interleukins. We hypothesized that neuroinflammation is critical for disease progression and selective COX‐1 inhibition, rather than COX‐2 inhibition, can reduce neuroinflammation and AD pathology. Here, we show that treatment of 20‐month‐old triple transgenic AD (3 × Tg‐AD) mice with the COX‐1 selective inhibitor SC‐560 improved spatial learning and memory, and reduced amyloid deposits and tau hyperphosphorylation. SC‐560 also reduced glial activation and brain expression of inflammatory markers in 3 × Tg‐AD mice, and switched the activated microglia phenotype promoting their phagocytic ability. The present findings are the first to demonstrate that selective COX‐1 inhibition reduces neuroinflammation, neuropathology, and improves cognitive function in 3 × Tg‐AD mice. Thus, selective COX‐1 inhibition should be further investigated as a potential therapeutic approach for AD.     

Tetramethylpyrazine Attenuates Cognitive Impairment Via Suppressing Oxidative Stress,Neuroinflammation, and Apoptosis in Type 2 Diabetic Rats

Cognitive dysfunction is an important complication observed in type 2 diabetes mellitus (T2DM) patients. Tetramethylpyrazine (TMP) is known to exhibit anti-diabetic and neuroprotective properties. Therefore, the present study aimed to investigate the possible therapeutic effects of TMP against type 2 diabetes-associated cognitive impairment in rats. High-fat diet (HFD) followed by a low dose of streptozotocin (35 mg/kg) was used to induce diabetes in Sprague–Dawley rats. TMP (20, 40, and 80 mg/kg) and Pioglitazone (10 mg/kg) were administered for 4 weeks. The Morris water maze (MWM) and novel objective recognition task (NOR) tests were used to assess memory function. Fasting blood glucose (FBG), lipid profile, HOMA-IR, glycosylated hemoglobin (HbA1c), and glucose tolerance were measured. Acetylcholinesterase (AChE) and choline acetytransferase (ChAT) activity, acetylcholine (ACh) levels, oxidative stress, apoptotic (Bcl-2, Bax, caspase-3), and inflammatory markers (TNF-α, IL-1β, and NF-kβ) were assessed. BDNF, p-AKT, and p-CREB levels were also measured. In the present work, we observed that treatment of diabetic rats with TMP alleviated learning and memory deficits, improved insulin sensitivity, and attenuated hyperglycemia and dyslipidemia. Furthermore, treatment with TMP increased BDNF, p-Akt, and p-CREB levels, normalized cholinergic dysfunction, and suppressed oxidative, inflammatory, and apoptotic markers in the hippocampus. Collectively, our results suggest that the TMP may be an effective neuroprotective agent in alleviating type 2 diabetes-associated cognitive deficits.

     

The in vivo cytokine release profile following implantation

There has been no comprehensive study that maps the production of the range of inflammatory cytokines following implantation of a material. There is an urgent requirement for specific data on the real time production of biological markers in order to study their effects in vitro and more accurately predict the in vivo response. This study determined the production of IL-1β, IL-2, IL-4, IL-6, IL-10, IFNγ and TNF-α in response to a synthetic material implanted in a rat soft tissue model for up to 90 days. IL-1 β and TNF-α were elevated over the total experimental time course with values in the order of 500 pg/ml for IL-1β and 40 pg/ml for TNF-α. The cytokines IL-2, IL-4, IL-6 and IL-10 were also detected and their production reduced with increasing time.     

Prostaglandin E2 EP2 Receptor Deletion Attenuates Intracerebral Hemorrhage-Induced Brain Injury and Improves Functional Recovery

Intracerebral hemorrhage (ICH) is a devastating type of stroke characterized by bleeding into the brain parenchyma and secondary brain injury resulting from strong neuroinflammatory responses to blood components. Production of prostaglandin E₂ (PGE₂) is significantly upregulated following ICH and contributes to this inflammatory response in part through its E prostanoid receptor subtype 2 (EP2). Signaling through the EP2 receptor has been shown to affect outcomes of many acute and chronic neurological disorders; although, not yet explored in the context of ICH. Wildtype (WT) and EP2 receptor knockout (EP2^−/−) mice were subjected to ICH, and various anatomical and functional outcomes were assessed by histology and neurobehavioral testing, respectively. When compared with age-matched WT controls, EP2^−/− mice had 41.9 ± 4.7% smaller ICH-induced brain lesions and displayed significantly less ipsilateral hemispheric enlargement and incidence of intraventricular hemorrhage. Anatomical outcomes correlated with improved functional recovery as identified by neurological deficit scoring. Histological staining was performed to begin investigating the mechanisms involved in EP2-mediated neurotoxicity after ICH. EP2^−/− mice exhibited 45.5 ± 5.8% and 41.4 ± 8.1% less blood and ferric iron accumulation, respectively. Furthermore, significantly less striatal and cortical microgliosis, striatal and cortical astrogliosis, blood–brain barrier breakdown, and peripheral neutrophil infiltration were seen in EP2^−/− mice. This study is the first to suggest a deleterious role for the PGE₂-EP2 signaling axis in modulating brain injury, inflammation, and functional recovery following ICH. Targeting the EP2 G protein-coupled receptor may represent a new therapeutic avenue for the treatment of hemorrhagic stroke.     

Puerarin attenuates intracerebral hemorrhage-induced early brain injury possibly by PI3K/Akt signal activation-mediated suppression of NF-κB pathway

Intracerebral hemorrhage (ICH) can induce intensively oxidative stress, neuroinflammation, and brain cell apoptosis. However, currently, there is no highly effective treatment available. Puerarin (PUE) possesses excellent neuroprotective effects by suppressing the NF-κB pathway and activating the PI3K/Akt signal, but its role and related mechanisms in ICH-induced early brain injury (EBI) remain unclear. In this study, we intended to observe the effects of PUE and molecular mechanisms on ICH-induced EBI. ICH was induced in rats by collagenase IV injection. PUE was intraperitoneally administrated alone or with simultaneously intracerebroventricular injection of LY294002 (a specific inhibitor of the PI3K/Akt signal). Neurological deficiency, histological impairment, brain edema, hematoma volume, blood–brain barrier destruction, and brain cell apoptosis were evaluated. Western blot, immunohistochemistry staining, reactive oxygen species (ROS) measurement, and enzyme-linked immunosorbent assay were performed. PUE administration at 50 mg/kg and 100 mg/kg could significantly reduce ICH-induced neurological deficits and EBI. Moreover, PUE could notably restrain ICH-induced upregulation of the NF-κB pathway, pro-inflammatory cytokines, ROS level, and apoptotic pathway and activate the PI3K/Akt signal. However, LY294002 delivery could efficaciously weaken these neuroprotective effects of PUE. Overall, PUE could attenuate ICH-induced behavioral defects and EBI possibly by PI3K/Akt signal stimulation-mediated inhibition of the NF-κB pathway, and this made PUE a potential candidate as a promising therapeutic option for ICH-induced EBI.     

MRI-Based Analysis of Intracerebral Hemorrhage in Mice Reveals Relationship between Hematoma Expansion and the Severity of Symptoms

Intracerebral hemorrhage (ICH) is featured by poor prognosis such as high mortality rate and severe neurological dysfunction. In humans, several valuables including hematoma volume and ventricular expansion of hemorrhage are known to correlate with the extent of mortality and neurological dysfunction. However, relationship between hematoma conditions and the severity of symptoms in animal ICH models has not been clarified. Here we addressed this issue by using 7-tesla magnetic resonance imaging (MRI) on collagenase-induced ICH model in mice. We found that the mortality rate and the performance in behavioral tests did not correlate well with the volume of hematoma. In contrast, when hemorrhage invaded the internal capsule, mice exhibited high mortality and showed poor sensorimotor performance. High mortality rate and poor performance in behavioral tests were also observed when hemorrhage invaded the lateral ventricle, although worsened symptoms associated with ventricular hemorrhage were apparent only during early phase of the disease. These results clearly indicate that invasion of the internal capsule or the lateral ventricle by hematoma is a critical determinant of poor prognosis in experimental ICH model in mice as well as in human ICH patients. MRI assessment may be a powerful tool to refine investigations of pathogenic mechanisms and evaluations of drug effects in animal models of ICH.