Microglia, the resident immune cells in the central nervous system (CNS), rapidly transition from a resting to an active state in the acute phase of ischemic brain injury. This active state mediates a pro-inflammatory response that can exacerbate the injury. Targeting the pro-inflammatory response of microglia in the semi-dark band during this acute phase may effectively reduce brain injury. Shionone (SH), an active ingredient extracted from the dried roots and rhizomes of the genus Aster (Asteraceae), has been reported to regulate the inflammatory response of macrophages in sepsis-induced acute lung injury. However, its function in post-stroke neuroinflammation, particularly microglia-mediated neuroinflammation, remains uninvestigated. This study found that SH significantly inhibited lipopolysaccharide (LPS)-induced elevation of inflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS), in microglia in vitro. Furthermore, the results demonstrated that SH alleviated infarct volume and improved behavioral performance in middle cerebral artery occlusion (MCAO) mice, which may be attributed to the inhibition of the microglial inflammatory response induced by SH treatment. Mechanistically, SH potently inhibited the phosphorylation of serine-threonine protein kinase B (AKT), mammalian target of rapamycin (mTOR), and signal transducer and activator of transcription 3 (STAT3). These findings suggest that SH may be a potential therapeutic agent for relieving ischemic stroke (IS) by alleviating microglia-associated neuroinflammation.
Animals ; Microglia/immunology* ; Mice ; Male ; Mice, Inbred C57BL ; Brain Ischemia/immunology* ; Neuroinflammatory Diseases/drug therapy* ; Neuroprotective Agents/administration & dosage* ; Interleukin-1beta/genetics* ; STAT3 Transcription Factor/genetics* ; TOR Serine-Threonine Kinases/genetics* ; Tumor Necrosis Factor-alpha/genetics* ; Proto-Oncogene Proteins c-akt/immunology* ; Nitric Oxide Synthase Type II/genetics* ; Lipopolysaccharides

Salvianolic acid A (SAA) is a water-soluble component from the root of Salvia Miltiorrhiza Bge, a traditional Chinese medicine, which has been used for the treatment of cerebrovascular diseases for centuries. The present study aimed to determine the brain protective effects of SAA against cerebral ischemia reperfusion injury in rats, and to figure out whether SAA could protect the blood brain barrier (BBB) through matrix metallopeptidase 9 (MMP-9) inhibition. A focal cerebral ischemia reperfusion model was induced by middle cerebral artery occlusion (MCAO) for 1.5-h followed by 24-h reperfusion. SAA was administered intravenously at doses of 5, 10, and 20 mg·kg. SAA significantly reduced the infarct volumes and neurological deficit scores. Immunohistochemical analyses showed that SAA treatments could also improve the morphology of neurons in hippocampus CA1 and CA3 regions and increase the number of neurons. Western blotting analyses showed that SAA downregulated the levels of MMP-9 and upregulated the levels of tissue inhibitor of metalloproteinase 1 (TIMP-1) to attenuate BBB injury. SAA treatment significantly prevented MMP-9-induced degradation of ZO-1, claudin-5 and occludin proteins. SAA also prevented cerebral NF-κB p65 activation and reduced inflammation response. Our results suggested that SAA could be a promising agent to attenuate cerebral ischemia reperfusion injury through MMP-9 inhibition and anti-inflammation activities.
Animals ; Anti-Inflammatory Agents ; administration & dosage ; Blood-Brain Barrier ; drug effects ; enzymology ; immunology ; Brain ; Brain Ischemia ; drug therapy ; enzymology ; genetics ; Caffeic Acids ; administration & dosage ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Lactates ; administration & dosage ; Male ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; enzymology ; genetics ; immunology ; prevention & control ; Salvia miltiorrhiza ; chemistry ; Tissue Inhibitor of Metalloproteinase-1 ; genetics ; metabolism ; Transcription Factor RelA ; genetics ; immunology

Brazilein is reported to have immunosuppressive effect on cardiovascular and cerebral-vascular diseases. The essential roles of innate immunity in cerebral ischemia are increasingly identified, but no studies concerning the influence of brazilein on the innate immunity receptors have been reported. The present study was designed to investigate the regulation of NOD2 (Nucleotide-binding oligomerization domain-containing protein 2) by brazilein for its protection of neuron in cerebral ischemia in vivo and oxygen-glucose deprivation in vitro. The results showed that brazilein could reverse the elevated expression of NOD2 and TNFα (tumor necrosis factor alpha) elicited by cerebral ischemia and reperfusion. This reduction could also be detected in normal mice and C17.2 cells, indicating that this suppressive effect of brazilein was correlated with NOD2. The results from GFP reporter plasmid assay suggested brazilein inhibited NOD2 gene transcription. In conclusion, brazilein could attenuate NOD2 and TNFα expression in cerebral ischemia and NOD2 may be one possible target of brazilein for its immune suppressive effect in neuro-inflammation.
Animals ; Benzopyrans ; administration & dosage ; Brain Ischemia ; drug therapy ; genetics ; immunology ; metabolism ; Cells, Cultured ; Drugs, Chinese Herbal ; administration & dosage ; Glucose ; metabolism ; Humans ; Indenes ; administration & dosage ; Male ; Mice ; Mice, Inbred ICR ; Neurons ; drug effects ; immunology ; Nod2 Signaling Adaptor Protein ; genetics ; metabolism ; Oxygen ; metabolism ; Tumor Necrosis Factor-alpha ; genetics ; immunology

OBJECTIVETo investigate the dynamic changes in CD4(+)CD25(+) regulatory T cells and Foxp3 expression in peripheral blood and brain tissues of rats after acute cerebral ischemia and explore their role in the pathophysiological evolution of acute ischemic stroke.

METHODSForty-eight Wistar rats were randomized equally into ischemia and sham-operated groups, and right middle cerebral artery occlusion was induced in the former group. Flow cytometry and immunohistochemistry were employed to detect CD4(+)CD25(+) T cells and Foxp3 expression, respectively, in the peripheral blood and brain tissue at 1, 3, 7, and 14 days after modeling. The behavioral changes of the rats were evaluated using an improved NSS neurological functional scoring system.

RESULTSThe neurological function scores of the two groups both gradually declined after the operation, and showed significant differences between the two groups at all the time points of measurement (P<0.01). The CD4(+)CD25 T cells in the peripheral blood were similar between the two group at 1 and 3 days after the operation (P>0.05), but increased significantly in the ischemia group at 7 and 14 days (P<0.05) with an inverse correlation to the neurological scores (r=-0.68, P=0.01). Immunohistochemistry detected the presence of Foxp3 primarily in the ischemic region of the brain tissue 1 day after cerebral ischemia; the contralateral hemisphere also showed a small quantity of Foxp3 expression. No Foxp3 expression was detected in the brain tissue of the sham-operated group.

CONCLUSIONCD4(+)CD25 T regulatory cells participate in the inflammatory immune reactions as early as 1 day after acute cerebral ischemia in rats, which might be a protective mechanism of the brain cells.

Animals ; Brain ; metabolism ; Brain Ischemia ; immunology ; metabolism ; Forkhead Transcription Factors ; immunology ; metabolism ; Male ; Rats ; Rats, Wistar ; T-Lymphocytes, Regulatory ; immunology ; metabolism

The aim of the present study is to investigate the role of nordihydroguaiaretic acid (NDGA) on inflammatory cells accumulation after focal cerebral ischemia and the underlying mechanism. Focal cerebral ischemia was induced by 30 min of middle cerebral artery occlusion (MCAO) followed by 72 h of reperfusion. NDGA (5 and 10 mg/kg) was administered intraperitoneally 30 min, 2, 24, 48 h after reperfusion, respectively. The brain injuries were observed by neurological and histological examination. Endogenous IgG exudation, neutrophils and macrophages/microglia accumulation, and intercellular adhesion molecule-1 (ICAM-1) protein expression were determined by immunohistochemistry 72 h after reperfusion. ICAM-1 mRNA was determined by RT-PCR 72 h after reperfusion. The catalysates of 5-lipoxygenase (5-LOX), leukotriene B4 (LTB4) and cysteinyl leukotrienes (CysLTs), were evaluated by ELISA 3 h after reperfusion. The results showed that NDGA ameliorated neurological dysfunction, decreased infarct volume, and inhibited endogenous IgG exudation, neutrophils infiltration, ICAM-1 mRNA and protein expression 72 h after reperfusion. Moreover, NDGA reduced the levels of LTB4 and CysLTs 3 h after reperfusion. However, NDGA did not reduce the accumulation of macrophages/microglia 72 h after reperfusion. These results suggest that NDGA decreases neutrophil infiltration in the subacute phase of focal cerebral ischemia via inhibiting 5-LOX activation.
Animals ; Arachidonate 5-Lipoxygenase ; metabolism ; Brain Ischemia ; complications ; physiopathology ; Immunoglobulin G ; immunology ; Inflammation ; etiology ; physiopathology ; prevention & control ; Intercellular Adhesion Molecule-1 ; genetics ; metabolism ; Leukotriene B4 ; metabolism ; Lipoxygenase Inhibitors ; pharmacology ; Male ; Masoprocol ; pharmacology ; Neutrophils ; drug effects ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; prevention & control

OBJECTIVETo investigate the effect of vasoactive intestinal peptide (VIP) on angiogenesis after focal cerebral ischemia.

METHODSFocal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 120 min in adult SD rats with intracerebroventricular VIP administration at the beginning of reperfusion. Immunohistochemistry was performed to assay BrdU immunoreactive endothelial cells, expressions of VEGF, flt-1 and flk-1 in the ischemic zone, and the protein expressions of vascular endothelial growth factor (VEGF) in the brain was measured using Western blotting.

RESULTSImmunohistochemical staining revealed significantly increased BrdU immunoreactive endothelial cells on the margins of the ischemic lesion in rats treated with VIP as compared with that in the control rats (P<0.05). VIP significantly increased the number of VEGF immunoreactive cells and flt-1- and flk-1-positive endothelial cells in comparison with the control group (P<0.01). Western blotting showed that VIP treatment resulted in significantly increased VEGF protein level in the ipsilateral hemisphere (P<0.05).

CONCLUSIONSVIP enhances angiogenesis in the ischemic brain by increasing the expressions of VEGF in the brain tissue and its receptors flt-1 and flk-1 in the endothelial cells.

Animals ; Brain ; drug effects ; metabolism ; Brain Ischemia ; immunology ; metabolism ; pathology ; physiopathology ; Endothelial Cells ; drug effects ; metabolism ; Gene Expression Regulation ; drug effects ; Male ; Neovascularization, Physiologic ; drug effects ; Rats ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor A ; metabolism ; Vascular Endothelial Growth Factor Receptor-1 ; metabolism ; Vascular Endothelial Growth Factor Receptor-2 ; metabolism ; Vasoactive Intestinal Peptide ; pharmacology

OBJECTIVETo stydy the protective mechanism of Jiedu Tongluo (JDTL) injection on experimental cerebral ischemia.

METHODRadioimmunoassay (RIA) was utilized to identify the content of TNF-alpha and IL1-beta in brain tissue of rats suffered from 6 h and 24 h ischemia with MCAO, Enzyme-linked immunoadsordent assay (ELISA) was used to observe the level of MCP-1 and ICMA-1.

RESULTAfter 6 h and 24 h of ischemia, the increased contents of TNF-alpha, IL1-beta, MCP-1 as well as ICMA-1 was observed. JDTL injection dramatically inhibited the increase of TNF-alpha, IL1-beta after 6 h and 24 h of ischemia.

CONCLUSIONJDTL injection had inhibiting effect on TNF-alpha, IL1-beta, MCP-1 as well as ICMA-1 caused by cerebral ischemia, the result suggested that JDIL injection can protect cerebral tissue from ischemic injury by inhibiting inflammatory factors.

Animals ; Brain ; drug effects ; immunology ; Brain Ischemia ; drug therapy ; immunology ; prevention & control ; Cytokines ; immunology ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Inflammation Mediators ; immunology ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVENogo-A antibody IN-1 can neutralize Nogo-A, a neurite growth inhibitory protein, promoting axonal regeneration following lesions of the central nervous system (CNS) in adult rats. This study aimed to examine the effect of ventricle injection of Nogo-A antibody on neuronal regeneration in neonatal rats following hypoxic-ischemic brain damage (HIBD).

METHODSA model of neonatal HIBD was prepared by the ligation of the left common carotid artery, followed by 8% hypoxia exposure. Forty HIBD rats were randomly given a ventricle injection of 10 microL Nogo-A antibody IN-1 (IN-1 group) or 10 microL artificial cerebrospinal fluid (artificial CSF group) (n=20 each). Another 20 neonatal rats were sham-operated, without hypoxia-ischemia, and were used as the controls. The levels of Nogo-A and GAP-43 protein in the brain were measured by immunohistochemistry.

RESULTSThe number of immunohistory positive cells of Nogo-A in the brain in the IN-1 group (28.61+/-1.70) was obviously less than that in the artificial CSF (39.52 +/-1.40) and the sham-operated groups (32.78 +/- 1.87) (both P < 0.01). There were significant differences in the Nogo-A protein expression between the artificial CSF and the sham-operated groups (P < 0.01). The GAP-43 protein expression in the IN-1 group (31.14 +/- 1.88) was noticeably higher than that in the artificial CSF group (27.73 +/- 1.43 ) (P < 0.01). Both the IN-1 and the artificial CSF groups showed lower GAP-43 protein levels than the sham-operated groups (33.64 +/- 1.24) (both P < 0.01).

CONCLUSIONSNogo-A antibody can reduce the expression of Nogo-A protein in the brain and thus promote neuronal regeneration in neonatal rats following HIBD. An increased GAP-43 protein expression in the brain after Nogo-A antibody administration shows an enhanced neuronal regeneration in the neonatal rats following HIBD.

Animals ; Animals, Newborn ; Antibodies ; administration & dosage ; Brain Chemistry ; Female ; GAP-43 Protein ; analysis ; Hypoxia-Ischemia, Brain ; metabolism ; physiopathology ; therapy ; Immunohistochemistry ; Injections, Intraventricular ; Male ; Myelin Proteins ; analysis ; antagonists & inhibitors ; immunology ; Nerve Regeneration ; Nogo Proteins ; Rats ; Rats, Sprague-Dawley

BACKGROUND: Ischemic stroke is a complex condition influenced by many factors. Previous studies have demonstrated that inflammatory markers might play a role in such vascular diseases. Therefore the purpose of this study was to compare the expression of inflammatory markers in Korean ischemic stroke patients and to investigate their relationship to APOE polymorphism. METHODS: The patient group consisted of 275 patients with large artery atherosclerosis (LAA, n=169) and small artery occlusion (SAO, n=106). One hundred and nineteen age matched healthy subjects were recruited as the control group. Serum levels of three inflammatory markers (matrix metalloproteinase, MMP-9; tissue inhibitor of metalloproteinase-1, TIMP-1; and high-sensitivity C-reactive protein, hs-CRP) were measured in each patient by using commercially available kits. Comparison of clinical risk factors, inflammatory marker levels, and APOE genotypes between the stroke patient group and control group and between the two patient subgroups was assessed. RESULTS: Comparison of the stroke group to control group showed significantly elevated levels of circulating MMP-9 (P<0.01) and hs-CRP (P=0.01). Comparison between the individual subgroups revealed a significantly higher level of only TIMP-1 in the LAA subgroup compared to the SAO subgroup (P<0.01). There was no significant difference in inflammatory marker levels among each allele carrier. CONCLUSIONS: The present study revealed the obvious tendency of increased circulating inflammatory markers in the patients with acute ischemic attack, especially MMP-9 and hs-CRP. Our observations suggest that measurement of serum MMP-9, TIMP-1, and hs-CRP levels may be useful in the diagnosis of ischemic stroke patients.
Aged ; Apolipoproteins E/*genetics ; Biological Markers/blood ; Brain Ischemia/complications/*diagnosis ; C-Reactive Protein/analysis ; Carotid Artery Diseases/complications ; Female ; Genotype ; Humans ; Inflammation Mediators/*blood ; Korea ; Male ; Matrix Metalloproteinase 9/blood ; Middle Aged ; Polymorphism, Genetic ; Stroke/*diagnosis/etiology/immunology ; Tissue Inhibitor of Metalloproteinase-1/blood

OBJECTIVETo investigate the neuro-protective effect of Xuesaitong Injection (XST) on brain inflammatory response after transient focal cerebral ischemia/reperfusion in rats.

METHODSFocal cerebral ischemia/reperfusion models of male rats were induced by transient occlusion for 2 h of middle cerebral artery (MCA) which was followed by 24 h reperfusion. XST was administered through intraperitoneal injection of 25 mg/kg or 50 mg/kg at 4 h after the onset of ischemia. After reperfusion for 24 h, the neurological function score was evaluated, the brain edema was detected with dry-wet weight method, the myeloperoxidase (MPO) activity and the expression of intercellular adhesion molecule-1 (ICAM-1) of ischemic cerebral cortex and caudate putamen was determined by spectrophotometry and immunohistochemistry respectively.

RESULTSXST not only lowered neurological function score at the dose of 50 mg/kg, but reduced brain edema and inhibited MPO activity and ICAM-1 expression as compared with the ischemia/reperfusion model group (P < 0.01).

CONCLUSIONXST has a definite effect on inhibiting the expression of ICAM-1 and neutrophil infiltration in rats with cerebral ischemia/reperfusion when treatment started at 4 h after ischemia onset, and also attenuates inflammation in the infarcted cerebral area.

Animals ; Brain Edema ; drug therapy ; immunology ; Brain Ischemia ; drug therapy ; immunology ; Encephalitis ; drug therapy ; immunology ; Intercellular Adhesion Molecule-1 ; metabolism ; Male ; Neuroprotective Agents ; pharmacology ; Neutrophils ; immunology ; Peroxidase ; metabolism ; Rats ; Rats, Wistar ; Reperfusion Injury ; drug therapy ; immunology ; Saponins ; pharmacology