Relationship between prior statin therapy and radiological features and clinical outcomes of intracerebral hemorrhage.

OBJECTIVES: A post-hoc analysis of the ICH Deferoxamine (i-DEF) trial was performed to examine any associations pre-ICH statin use may have with ICH volume, PHE volume, and clinical outcomes. MATERIALS AND METHODS: Baseline characteristics were assessed. Various ICH and PHE parameters were measured via a quantitative, semi-automated method at baseline and follow-up CT scans 72-96 h later. A multivariable logistic regression model was created, adjusting for the variables that were significantly different on univariable analyses (p < 0.05), to assess any associations between pre-ICH statin use and measures of ICH and PHE, as well as good clinical outcome (mRS ≤2), at 90 and 180 days. RESULTS: 262 of 291 i-DEF participants had complete data available for analysis. 69 (26.3 %) used statins prior to ICH onset. Pre-ICH statin users had higher prevalences of hypertension, diabetes, and prior ischemic stroke; higher concomitant use of antihypertensives and antiplatelets; and higher blood glucose level at baseline. On univariable analyses, pre-ICH statin users had smaller baseline ICH volume and PHE volume on repeat scan, as well as smaller changes in relative PHE (rPHE) volume and edema extension distance (EED) between the baseline and repeat scans. In the multivariable analysis, none of the ICH and PHE measures or good clinical outcome was significantly associated with pre-ICH statin use. CONCLUSION: Pre-ICH statin use was not associated with measures of ICH or PHE, their growth, or clinical outcomes. These findings do not lend support to either overall protective or deleterious effects from statin use before or after ICH.

Histone Deacetylase 3 Inhibition Decreases Cerebral Edema and Protects the Blood-Brain Barrier After Stroke.

We have previously shown that selective inhibition of histone deacetylase 3 (HDAC3) decreases infarct volume and improves long-term functional outcomes after stroke. In this study, we examined the effects of HDAC3 inhibition on cerebral edema and blood-brain barrier (BBB) leakage and explored its underlying mechanisms. Adult male Wistar rats were subjected to 2-h middle cerebral artery occlusion (MCAO) and randomly treated i.p. with either vehicle or a selective HDAC3 inhibitor (RGFP966) at 2 and 24 h after stroke. Modified neurological severity scores (mNSS) were calculated at 2 h, 1 day, and 3 days. H&E, Evans blue dye (EBD) assay, and fluorescein isothiocyanate (FITC)-dextran were employed to assess cerebral edema and BBB leakage. Western blot for matrix metalloproteinase-9 (MMP9), MMP-9 zymography, and immunostaining for HDAC3, GFAP, Iba-1, albumin, aquaporin-4, claudin-5, ZO-1, and NF-kB were performed. Early RGFP966 administration decreased cerebral edema (p = 0.002) and BBB leakage, as measured by EBD assay, FITC-dextran, and albumin extravasation (p < 0.01). RGFP966 significantly increased tight junction proteins (claudin-5 and ZO-1) in the peri-infarct area. RGFP966 also significantly decreased HDAC3 in GFAP + astrocytes, which correlated with better mNSS (r = 0.67, p = 0.03) and decreased cerebral edema (r = 0.64, p = 0.04). RGFP966 decreased aquaporin-4 in GFAP + astrocytes (p = 0.002), as well as, the inflammatory markers Iba-1, NF-kB, and MMP9 in the ischemic brain (p < 0.05). Early HDAC3 inhibition decreases cerebral edema and BBB leakage. BBB protection by RGFP966 is mediated in part by the upregulation of tight junction proteins, downregulation of aquaporin-4 and HDAC3 in astrocytes, and decreased neuroinflammation.

Sepsis-associated brain injury: underlying mechanisms and potential therapeutic strategies for acute and long-term cognitive impairments.

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis causes cerebral dysfunction in the short and long term and induces disruption of the blood-brain barrier (BBB), neuroinflammation, hypoperfusion, and accumulation of amyloid ß (Aß) and tau protein in the brain. White matter changes and brain atrophy can be detected using brain imaging, but unfortunately, there is no specific treatment that directly addresses the underlying mechanisms of cognitive impairments in sepsis. Here, we review the underlying mechanisms of sepsis-associated brain injury, with a focus on BBB dysfunction and Aß and tau protein accumulation in the brain. We also describe the neurological manifestations and imaging findings of sepsis-associated brain injury, and finally, we propose potential therapeutic strategies for acute and long-term cognitive impairments associated with sepsis. In the acute phase of sepsis, we suggest using antibiotics (such as rifampicin), targeting proinflammatory cytokines, and preventing ischemic injuries and hypoperfusion. In the late phase of sepsis, we suggest targeting neuroinflammation, BBB dysfunction, Aß and tau protein phosphorylation, glycogen synthase kinase-3 beta (GSK3ß), and the receptor for advanced glycation end products (RAGE). These proposed strategies are meant to bring new mechanism-based directions for future basic and clinical research aimed at preventing or ameliorating acute and long-term cognitive impairments in patients with sepsis.

Effect of Deferoxamine on Trajectory of Recovery After Intracerebral Hemorrhage: A Post Hoc Analysis of the i-DEF Trial.

BACKGROUND: There are limited data on the trajectory of recovery and long-term functional outcomes after intracerebral hemorrhage (ICH). Most ICH trials have conventionally assessed outcomes at 3 months following the footsteps of ischemic stroke. The i-DEF trial (Intracerebral Hemorrhage Deferoxamine Trial) assessed modified Rankin Scale (mRS) longitudinally at prespecified time points from day 7 through the end of the 6-month follow-up period. We evaluated the trajectory of mRS among trial participants and examined the effect of deferoxamine on this trajectory. METHODS: We performed a post hoc analysis of the i-DEF trial, a multicenter, randomized, placebo-controlled, double-blind, futility-design, phase 2 clinical trial, based on the actual treatment received. Favorable outcome was defined as mRS score of 0-2. A generalized linear mixed model was used to evaluate the outcome trajectory over time, as well as whether the trajectory was altered by deferoxamine, after adjustments for randomization variables, presence of intraventricular hemorrhage, and ICH location. RESULTS: A total of 291 subjects were included in analysis (145 placebo and 146 deferoxamine). The proportion of patients with mRS score of 0-2 continually increased from day 7 to 180 in both groups (interaction P<0.0001 for time in main effects model), but treatment with deferoxamine favorably altered the trajectory (interaction P=0.0010). Between day 90 and 180, the deferoxamine group improved (P=0.0001), whereas there was not significant improvement in the placebo arm (P=0.3005). CONCLUSIONS: A large proportion of patients continue to improve up to 6 months after ICH. Future ICH trials should assess outcomes past 90 days for a minimum of 6 months. In i-DEF, treatment with deferoxamine seemed to accelerate and alter the trajectory of recovery as assessed by mRS. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02175225.

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.

Epigenetics in Stroke Recovery.

While the death rate from stroke has continually decreased due to interventions in the hyperacute stage of the disease, long-term disability and institutionalization have become common sequelae in the aftermath of stroke. Therefore, identification of new molecular pathways that could be targeted to improve neurological recovery among survivors of stroke is crucial. Epigenetic mechanisms such as post-translational modifications of histone proteins and microRNAs have recently emerged as key regulators of the enhanced plasticity observed during repair processes after stroke. In this review, we highlight the recent advancements in the evolving field of epigenetics in stroke recovery.

Class IIa histone deacetylases affect neuronal remodeling and functional outcome after stroke.

We have previously demonstrated that stroke induces nuclear shuttling of class IIa histone deacetylase 4 (HDAC4). Stroke-induced nuclear shuttling of HDAC4 is positively and significantly correlated with improved indices of neuronal remodeling in the peri-infarct cortex. In this study, using a rat model for middle cerebral artery occlusion (MCAO), we tested the effects of selective inhibition of class IIa HDACs on functional recovery and neuronal remodeling when administered 24hr after stroke. Adult male Wistar rats (n = 15-17/group) were subjected to 2 h MCAO and orally gavaged with MC1568 (a selective class IIa HDAC inhibitor), SAHA (a non-selective HDAC inhibitor), or vehicle-control for 7 days starting 24 h after MCAO. A battery of behavioral tests was performed. Lesion volume measurement and immunohistochemistry were performed 28 days after MCAO. We found that stroke increased total HDAC activity in the ipsilateral hemisphere compared to the contralateral hemisphere. Stroke-increased HDAC activity was significantly decreased by the administration of SAHA as well as by MC1568. However, SAHA significantly improved functional outcome compared to vehicle control, whereas selective class IIa inhibition with MC1568 increased mortality and lesion volume and did not improve functional outcome. In addition, MC1568 decreased microtubule associated protein 2 (MAP2, dendrites), phosphorylated neurofilament heavy chain (pNFH, axons) and myelin basic protein (MBP, myelination) immunoreactivity in the peri-infarct cortex. Quantitative RT-PCR of cortical neurons isolated by laser capture microdissection revealed that MC1568, but not SAHA, downregulated CREB and c-fos expression. Additionally, MC1568 decreased the expression of phosphorylated CREB (active) in neurons. Taken together, these findings demonstrate that selective inhibition of class IIa HDACs impairs neuronal remodeling and neurological outcome. Inactivation of CREB and c-fos by MC1568 likely contributes to this detrimental effect.

Stroke Induces Nuclear Shuttling of Histone Deacetylase 4.

BACKGROUND AND PURPOSE: Histone deacetylases (HDACs) 4 and 5 are abundantly expressed in the brain and have been implicated in the regulation of neurodegeneration. Under physiological conditions, HDACs 4 and 5 are expressed in the cytoplasm of brain cells where they cannot directly access chromatin. In response to external stimuli, they can shuttle to the nucleus and regulate gene expression. However, the effect of stroke on nuclear shuttling of HDACs 4 and 5 remains unknown. METHODS: Using a rat model of middle cerebral artery occlusion, we examined the subcellular localization of HDACs 4 and 5 in the peri-infarct cortex during brain repair after stroke. RESULTS: Stroke significantly increased nuclear HDAC4 immunoreactivity in neurons, but not in astrocytes or in oligodendrocytes, of the peri-infarct cortex at 2, 7, and 14 days after middle cerebral artery occlusion. Neurons with nuclear HDAC4 immunoreactivity distributed across all layers of the peri-infarct cortex and were Ctip2+ excitatory and parvalbumin+ inhibitory neurons. These neurons were not TUNEL or BrdU positive. Furthermore, nuclear HDAC4 immunoreactivity was positively and significantly correlated with increased dendritic, axonal, and myelin densities as determined by microtubule-associated protein 2, phosphorylated neurofilament heavy chain, and myelin basic protein, respectively. Unlike HDAC4, stroke did not alter nuclear localization of HDAC5. CONCLUSIONS: Our data show that stroke induces nuclear shuttling of HDAC4 in neurons in the peri-infarct cortex, and that increased nuclear HDAC4 is strongly associated with neuronal remodeling but not with neuronal cell death, suggesting a role for nuclear HDAC4 in promoting neuronal recovery after ischemic injury.

Histone deacetylase expression in white matter oligodendrocytes after stroke.

Histone deacetylases (HDACs) constitute a super-family of enzymes grouped into four major classes (Class I-IV) that deacetylate histone tails leading to chromatin condensation and gene repression. Whether stroke-induced oligodendrogenesis is related to the expression of individual HDACs in the oligodendrocyte lineage has not been investigated. We found that 2 days after stroke, oligodendrocyte progenitor cells (OPCs) and mature oligodendrocytes (OLGs) were substantially reduced in the peri-infarct corpus callosum, whereas at 7 days after stroke, a robust increase in OPCs and OLGs was observed. Ischemic brains isolated from rats sacrificed 7 days after stroke were used to test levels of individual members of Class I (1 and 2) and Class II (4 and 5) HDACs in white matter oligodendrocytes during stroke-induced oligodendrogenesis. Double immunohistochemistry analysis revealed that stroke substantially increased the number of NG2+OPCs with nuclear HDAC1 and HDAC2 immunoreactivity and cytoplasmic HDAC4 which were associated with augmentation of proliferating OPCs, as determined by BrdU and Ki67 double reactive cells after stroke. A decrease in HDAC1 and an increase in HDAC2 immunoreactivity were detected in mature adenomatous polyposis coli (APC) positive OLGs, which paralleled an increase in newly generated BrdU positive OLGs in the peri-infarct corpus callosum. Concurrently, stroke substantially decreased the acetylation levels of histones H3 and H4 in both OPCs and OLGs. Taken together, these findings demonstrate that stroke induces distinct profiles of Class I and Class II HDACs in white matter OPCs and OLGs, suggesting that the individual members of Class I and II HDACs play divergent roles in the regulation of OPC proliferation and differentiation during brain repair after stroke.

Human placenta-derived adherent cell treatment of experimental stroke promotes functional recovery after stroke in young adult and older rats.

BACKGROUND: Human Placenta-Derived Adherent Cells (PDAC®) are a novel mesenchymal-like cell population derived from normal human placental tissue. PDA-001 is a clinical formulation of PDAC® developed for intravenous administration. In this study, we investigated the efficacy of PDA-001 treatment in a rat model of transient middle cerebral artery occlusion (MCAo) in young adult (2-3 month old) and older rats (10-12 months old). METHODS: To evaluate efficacy and determine the optimal number of transplanted cells, young adult Wistar rats were subjected to MCAo and treated 1 day post MCAo with 1×10(6), 4×10(6) or 8×10(6) PDA-001 cells (i.v.), vehicle or cell control. 4×10(6) or 8×10(6) PDA-001 cells were also tested in older rats after MCAo. Treatment response was evaluated using a battery of functional outcome tests, consisting of adhesive-removal test, modified Neurological Severity Score (mNSS) and foot-fault test. Young adult rats were sacrificed 56 days after MCAo, older rats were sacrificed 29 days after MCAo, and lesion volumes were measured using H&E. Immunohistochemical stainings for bromodeoxyuridine (BrdU) and von Willebrand Factor (vWF), and synaptophysin were performed. RESULTS: In young adult rats, treatment with 4×10(6) PDA-001 cells significantly improved functional outcome after stroke (p<0.05). In older rats, significant functional improvement was observed with PDA-001 cell therapy in both of the 4×10(6) and 8×10(6) treatment groups. Functional benefits in young adult and older rats were associated with significant increases in the number of BrdU immunoreactive endothelial cells, vascular density and perimeter in the ischemic brain, as well as significantly increased synaptophysin expression in the ischemic border zone (p<0.05). CONCLUSION: PDA-001 treatment significantly improved functional outcome after stroke in both young adult and older rats. The neurorestorative effects induced by PDA-001 treatment may be related to increased vascular density and synaptic plasticity.

Efficacy of single and multiple injections of human umbilical tissue-derived cells following experimental stroke in rats.

INTRODUCTION: Human umbilical tissue-derived cells (hUTC) are a promising source of cells for regenerative treatment of stroke. In this study, we tested the efficacy of hUTC in experimental stroke and whether multiple injections of hUTC provide additional therapeutic benefits as compared to a single injection. METHODS: Adult male Wistar rats were subjected to 2 hours of middle cerebral artery occlusion (MCAo), and randomly selected animals were injected (i.v) with 3×106 hUTC or with vehicle control (at day: 1, 1&3 or 1&7 after MCAo, n = 8-9/group). A battery of functional outcome tests was performed at days 1, 7, 14, 21, 28, 35, 42, 49, 56 and 63 after MCAo. Rats were sacrificed at 63 days after MCAo and lesion volumes were measured. To investigate the underlying mechanism of hUTC treatment of stroke, Von Willebrand Factor (vWF), and Synaptophysin immunostaining were performed. RESULTS: All hUTC treated groups, single or multiple injections, had better functional recovery compared to control (p<0.01). There was no statistically significant difference between a single and multiple injections of hUTC (p = 0.23) or between different multiple injections groups (p>0.07) in functional outcome. All hUTC treatment groups showed significant increases in Synaptophysin, vascular density and perimeter compared to the control group (p<0.05). There was no statistically significant difference between a single and multiple injections of hUTC or between the two groups of multiple injections in all immunohistochemical measurements (p>0.1). CONCLUSION: hUTC treatment significantly improves long term functional outcome after stroke and promotes vascular density and synaptic plasticity. At the proscribed doses, multiple injections of hUTC were not superior to single injection therapy in both functional outcome and histological assessments.

Neuroprotective effect of human placenta-derived cell treatment of stroke in rats.

UNLABELLED: Human placenta-derived adherent (PDA001) cells are mesenchymal-like stem cells isolated from postpartum placenta. In this study, we tested whether intravenously infused PDA001 improves neurological functional recovery after stroke in rats. In addition, potential mechanisms underlying the PDA001-induced neuroprotective effect were investigated. Young adult male rats (2­3 months) were subjected to 2 h of middle cerebral artery occlusion (MCAo) and treated with PDA001 (4x10(6)) or vehicle controls [dextran vehicle or phosphate buffer saline (PBS)] via intravenous (IV) administration initiated at 4 h after MCAo. A battery of functional tests and measurements of lesion volume and apoptotic cells were performed. Immunostaining and ELISA assays for vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) and brain derived neurotrophic factor (BDNF) were performed in the ischemic brain to test the potential mechanisms underlying the neuroprotective effects of PDA001 cell treatment of stroke. PDA001 cell treatment at 4 h post stroke significantly improved functional outcome and significantly decreased lesion volume, TUNEL, and cleaved caspase 3-positive cell number in the ischemic brain, compared to MCAo-vehicle and MCAo-PBS control. Treatment of stroke with PDA001 cells also significantly increased HGF and VEGF expression in the ischemic border zone (IBZ) compared to controls. Using ELISA assays, treatment of stroke with PDA001 cells significantly increased VEGF, HGF, and BDNF levels in the ischemic brain compared to controls. CONCLUSION: When administered intravenously at 4 h after MCAo, PDA001 cells promoted neuroprotective effects. These effects induced by PDA001 cell treatment may be related to the increase of VEGF, HGF, and BDNF expression,and a decrease of apoptosis. PDA001 cells may provide a viable cell source to treat stroke.

Therapeutic benefit of treatment of stroke with simvastatin and human umbilical cord blood cells: neurogenesis, synaptic plasticity, and axon growth.

The therapeutic efficacy of cell-based therapy after stroke can be enhanced by making the host brain tissue more receptive to the administered cells, which thereby facilitates brain plasticity. We hypothesized that simvastatin increases human umbilical cord blood cell (HUCBC) migration into the ischemic brain and promotes brain plasticity and neurological functional outcome after stroke. Rats were subjected to 2-h middle cerebral artery occlusion (MCAo) and administered subtherapeutic doses of simvastatin (0.5 mg/kg, gavaged daily for 7 days), HUCBCs (1 × 10(6), one time injection via tail vein), or combination simvastatin with HUCBCs starting at 24 h after stroke. Combination treatment of stroke showed an interactive effect in improvement of neurological outcome compared with simvastatin or HUCBC monotherapy groups. In addition, combination treatment significantly increased brain-derived neurotrophic factor/TrkB expression and the number of engrafted HUCBCs in the ischemic brain compared with HUCBC monotherapy. The number of engrafted HUCBCs was significantly correlated with functional outcome (modified neurological severity score). Combination treatment significantly increased neurogenesis and synaptic plasticity in the ischemic brain, and promoted neuroblast migration in cultured subventricular zone explants. Using primary cultured neurons (PCNs), we found that combination treatment enhanced neurite outgrowth compared with nontreatment control, simvastatin or HUCBC supernatant monotherapy. Inhibition of TrkB significantly attenuated combination treatment-induced neurite outgrowth. Our data indicate that combination simvastatin and HUCBC treatment of stroke increases BDNF/TrkB expression, enhances HUCBC migration into the ischemic brain, amplifies endogenous neurogenesis, synaptic plasticity and axonal growth, and thereby improves functional outcome after stroke.

Niaspan enhances vascular remodeling after stroke in type 1 diabetic rats.

We investigated the changes and the molecular mechanisms of cerebral vascular damage and tested the therapeutic effects of Niaspan in type-1 streptozotocin induced diabetic (T1DM) rats after stroke. T1DM-rats were subjected to transient middle cerebral artery occlusion (MCAo) and treated without or with Niaspan. Non-streptozotocin rats (WT) were also subjected to MCAo. Functional outcome, blood-brain-barrier (BBB) leakage, brain hemorrhage, immunostaining, and rat brain microvascular endothelial cell (RBEC) culture were performed. Compared to WT-MCAo-rats, T1DM-MCAo-rats did not show an increase lesion volume, but exhibited significantly increased brain hemorrhage, BBB leakage and vascular damage as well as decreased functional outcome after stroke. Niaspan treatment of stroke in T1DM-MCAo-rats significantly attenuated BBB damage, promoted vascular remodeling and improved functional outcome after stroke. T1DM-MCAo-rats exhibited significantly increased Angiopoietin 2 (Ang2) expression, but decreased Ang1 expression in the ischemic brain compared to WT-MCAo-rats. Niaspan treatment attenuated Ang2, but increased Ang1 expression in the ischemic brain in T1DM-MCAo-rats. In vitro data show that the capillary-like tube formation in the WT-RBECs marginally increased compared to T1DM-RBEC. Niaspan and Ang1 treatment significantly increased tube formation compared to non-treatment control. Inhibition of Ang1 attenuated Niacin-induced tube formation in T1DM-RBECs. Niaspan treatment of stroke in T1DM-rats promotes vascular remodeling and improves functional outcome. The Ang1/Ang2 pathway may contribute to Niaspan induced brain plasticity. Niaspan warrants further investigation as a therapeutic agent for the treatment of stroke in diabetics.

Combination treatment with low-dose Niaspan and tissue plasminogen activator provides neuroprotection after embolic stroke in rats.

INTRODUCTION: Niaspan, an extended-release formulation of niacin (vitamin B3), has been widely used to increase high density lipoprotein (HDL) cholesterol and to prevent cardiovascular diseases and stroke. We have previously demonstrated that Niaspan (40 mg/kg) administered at 2h after stroke induces neuroprotection, while low dose Niaspan (20mg/kg) does not reduce infarct volume. Tissue plasminogen activator (tPA) is an effective therapy for acute stroke, but its use remains limited by a narrow therapeutic window. We have previously demonstrated that intravenous administration of tPA 4h after stroke in rats does not reduce infarct volume. In this study, we tested whether combination treatment with low-dose Niaspan (20mg/kg) and tPA administered 4h after embolic stroke in a rat model reduces infarct volume and provides neuroprotection. METHODS: Adult male Wistar rats were subjected to embolic middle cerebral artery occlusion (MCAo) and treated with low-dose Niaspan (20mg/kg) alone (n = 7), tPA (10mg/kg) alone (n = 7), combination of low-dose Niaspan and tPA (n = 7), or saline control (n = 9), 4h after stroke. A battery of functional outcome tests was performed. Rats were sacrificed at 7 days after MCAo and lesion volumes were measured. To investigate the underlying mechanism of combination treatment neuroprotective effect, deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), cleaved caspase-3, tumor necrosis factor alpha (TNF-alpha), and toll-like receptor 4 (TLR-4) immunostaining were performed. RESULTS: Combination treatment with low-dose Niaspan and tPA significantly improved functional outcome compared to the saline control group (p<0.05), while treatment with Niaspan or tPA alone did not significantly improve functional outcome compared to saline control group. Additionally, combination treatment significantly reduced infarct volume compared to saline control group (p = 0.006) and infarct volume was significantly correlated with functional outcome (p = 0.0008; r = 0.63). Monotherapy with Niaspan or tPA did not significantly decrease infarct volume compared to saline control group. Combination treatment reduced apoptosis as measured by significant reduction in the number of TUNEL-positive cells and cleaved caspase-3 expression in the ischemic brain compared to saline control group (p<0.05). Combination treatment also significantly reduced the expression of TNF-alpha and TLR-4 in the ischemic brain compared to Niaspan, tPA and saline treatment groups (p<0.05). A significant interaction between Niaspan and tPA on the TNF-alpha expression was detected (p<0.05), indicating a synergy effect in the combination treatment group. CONCLUSION: Treatment of stroke with combination of low-dose Niaspan and tPA at 4h after embolic stroke reduces infarct volume, improves neurological outcome and provides neuroprotection. The neuroprotective effects of combination treatment were associated with reduction of apoptosis and attenuation of TNF-alpha and TLR-4 expression.

Niaspan treatment induces neuroprotection after stroke.

INTRODUCTION: Niaspan, an extended-release formulation of Niacin (vitamin B3), has been widely used to increase high density lipoprotein (HDL) cholesterol and to prevent cardiovascular diseases and stroke. In this study, we tested whether Niaspan administered acutely after stroke is neuroprotective. METHODS: Adult male rats (n=8/group) were subjected to 2h of middle cerebral artery occlusion (MCAo) and treated with or without different doses of Niaspan (20, 40 or 80 mg/kg) at 2 and 24h after MCAo. A battery of functional outcome tests was performed, and serum HDL and triglycerides were measured. Rats were sacrificed at 7 days after MCAo and lesion volumes were measured. The optimal dose of Niaspan treatment of stroke was chosen for immunostaining: deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), cleaved caspase-3, tumor necrosis factor alpha (TNF-alpha), vascular endothelial growth factor (VEGF) and phosphorylated phosphatidylinositol 3-kinase (p-PI3K). Another set of rats (n=4/group) were killed at 7 days after MCAo for Western blot assay. RESULTS: Niaspan dose-dependently reduced infarct volume and improved functional outcome after stroke. No significant difference in HDL and triglyceride levels was detected between Niaspan treatments and MCAo control groups. Niaspan treatment significantly decreased the number of TUNEL-positive cells (105+/-17) and cleaved caspase-3 expression (381+/-33) in the ischemic brain compared to MCAo control (165+/-18; 650+/-61, respectively; p

Combination treatment of experimental stroke with Niaspan and Simvastatin, reduces axonal damage and improves functional outcome.

In this study we examined the effect of combination treatment of experimental stroke with Niaspan, a prolonged-release formulation of Niacin (vitamin B3), and Simvastatin, a cholesterol-lowering drug, on functional outcome, axonal damage, axonal density and the of Iba-1 immunoreactive microglia expression in the ischemic brain of rats. Adult male rats were subjected to 2 h middle cerebral artery occlusion (MCAo) and treated with or without Niaspan alone, Simvastatin alone and combination Niaspan and Simvastatin starting 24 h after MCAo and daily for 14 days. Neurological functional tests were performed. Axonal damage and density were evaluated by Amyloid Precursor Protein (APP) and Bielschowsky silver, respectively. Nogo66 Receptor (NgR) expression and immunoreactive microglia (Iba-1) were also measured in the ischemic brain. Niaspan and Simvastatin monotherapy and combination treatment significantly promote functional outcome after stroke (p<0.05) compared to MCAo control animals. Combination treatment with Niaspan and Simvastatin induces additive but not synergetic effects when compared to Niaspan or Simvastatin monotherapy groups. Combination treatment significantly decreased APP expression and increased Bielschowsky silver expression. NGR and Iba-1 expression were significantly decreased in the ischemic brain. These data suggest that treatment of experimental stroke with combination of Niaspan and Simvastatin significantly improves functional outcome, reduces axonal damage and increases axonal density. Decreased expression of the NGR and reduced activated microglia may contribute to functional recovery after stroke.

Comparison of bone marrow stromal cells derived from stroke and normal rats for stroke treatment.

BACKGROUND AND PURPOSE: We compared the effect of treatment of stroke with bone marrow stromal cells from stroke rats (Isch-BMSC) and normal rats (Nor-BMSC) on functional outcome. METHODS: Isch-BMSCs and Nor-BMSCs were intravenously injected into rats 24 hours after middle cerebral artery occlusion. To test the mechanism of Isch-BMSC-enhanced neurorestoration, Isch-BMSC and Nor-BMSC cultures were used. RESULTS: Isch-BMSC significantly promoted functional outcome and enhanced angiogenesis, arterial density, and axonal regeneration compared with Nor-BMSC treatment animals. Isch-BMSCs exhibited increased Angiopoietin-1, Tie2, basic fibroblast growth factor, glial cell-derived neurotrophic factor, vascular endothelial growth factor, and Flk1 gene expression compared with Nor-BMSC. Using transwell coculture of BMSCs with brain-derived endothelial cells, Isch-BMSCs increased phosphorylated-Tie2 activity in brain-derived endothelial cells and enhanced brain-derived endothelial cells capillary tube formation compared with Nor-BMSCs. Inhibition of Tie2 gene expression in brain-derived endothelial cells using siRNA significantly attenuated BMSC-induced capillary tube formation. CONCLUSIONS: These data suggest that Isch-BMSCs are superior to Nor-BMSCs for the neurorestorative treatment of stroke, which may be mediated by the enhanced trophic factor and angiogenic characteristics of Isch-BMSCs.

Treatment of stroke with a synthetic liver X receptor agonist, TO901317, promotes synaptic plasticity and axonal regeneration in mice.

In this study, we tested the hypothesis that TO901317 promotes synapse plasticity and axonal regeneration after stroke. Adult male C57BL/6J mice were subjected to middle cerebral artery occlusion (MCAo) and treated with or without TO901317 starting 24 h after MCAo daily for 14 days. Axonal damage and regeneration were evaluated by immunostaining. TO901317 significantly increased synaptophysin expression and axonal regeneration, as well as decreased the expressions of amyloid betaA4 precursor protein and Nogo receptor (NgR) in the ischemic brain. To test whether TO901317 regulates the phosphorylation of phosphatidylinositol 3-kinase (p-PI3K) and Akt (p-Akt) activity in the ischemic brain, MCAo mice were treated with or without TO901317 starting 24 h after MCAo daily for 4 days and were then killed at 5 days after MCAo. TO901317 treatment significantly increased p-PI3K and p-Akt activity, but did not increase total PI3K expression in the ischemic brain. Using primary cortical neuron (PCN) culture, TO901317 significantly increased synaptophysin expression, p-PI3K activity, and decreased NgR expression compared with nontreated controls. TO901317 also significantly increased neurite outgrowth, and inhibition of the PI3K/Akt pathway by LY294002 decreased neurite outgrowth in both controls and TO901317-treated groups in cultured hypoxic PCN. These data indicate that TO901317 promotes synaptic plasticity and axonal regeneration, and that PI3K/Akt signaling activity contributes to neurite outgrowth.