scholarly journals Role of Soluble Epoxide Hydrolase in the Sex-Specific Vascular Response to Cerebral Ischemia

2009 ◽  
Vol 29 (8) ◽  
pp. 1475-1481 ◽  
Author(s):  
Wenri Zhang ◽  
Jeffrey J Iliff ◽  
Caitlyn J Campbell ◽  
Ruikang K Wang ◽  
Patricia D Hurn ◽  
...  

Soluble epoxide hydrolase (sEH), a key enzyme in the metabolism of vasodilator eicosanoids called epoxyeicosatrienoic acids (EETs), is sexually dimorphic and suppressed by estrogen. We determined if the sex difference in blood flow during focal cerebral ischemia is linked to sEH. Soluble epoxide hydrolase expression in brain, hydrolase activity in cerebral vessels, and plasma 14,15-dihydroxyeicosatrienoic acid (14,15-DHET) were determined in male and female wild-type (WT) and sEH knockout (sEHKO) mice. Male, female, and ovariectomized female WT and sEHKO mice were subjected to 2-h middle cerebral artery occlusion (MCAO) and infarct size was measured at 24 h of reperfusion. Laser—Doppler cortical perfusion during MCAO was compared among groups and differences in cortical blood flow rates were confirmed using in vivo quantitative optical microangiography. Cerebrovascular expression and activity of sEH and plasma 14,15-DHET were lower in WT female than male mice, and blood flow during MCAO was higher and infarct size was smaller in WT female compared with male mice. Sex differences in cerebral blood flow and ischemic damage were abolished after ovariectomy and were absent in sEHKO mice. We conclude that sEH is an important mechanism underlying sex-linked differences in blood flow and brain damage after cerebral ischemia.

1997 ◽  
Vol 17 (10) ◽  
pp. 1057-1065 ◽  
Author(s):  
Sachiko Osuga ◽  
Matthew J. Hogan

Cell membrane depolarization and tissue acidosis occur rapidly in severely ischemic brain. Preischemic hyperglycemia is recognized to increase ischemic tissue acidosis and the present studies were undertaken to correlate depolarization and tissue acidosis during acute focal cerebral ischemia and hyperglycemia. We used a dual-label autoradiography method to simultaneously measure the in vivo distribution of [3H]nimodipine and [14C]DMO (5,5-dimethyl-2,4-oxazolidinedione) in brain to identify regions of ischemic depolarization and measure regional net tissue pH. Regional cerebral blood flow (CBF) was measured in separate studies. Measurements were made 30 minutes after combined middle cerebral artery and ipsilateral common carotid artery occlusion in normoglycemic and hyperglycemic rats. Tissue pH in the ischemic cortex was depressed to 6.76 ± 0.11 in normoglycemic rats (n = 12) and 6.57 ± 0.13 in hyperglycemic rats (n = 12), with significantly greater acidosis in the hyperglycemic group ( P < 0.001). In contrast the ratio of [3H]nimodipine uptake in the ischemic cortex relative to the contralateral nonischemic cortex was significantly greater in normoglycemic (1.83 ± 0.45) than hyperglycemic (1.40 ± 0.50) rats ( P < 0.05). Within this region of ischemic cortex CBF was 31 ± 22 mL/100 g in normoglycemic rats (n = 8) and 33 ± 22 mL/100 g/min in hyperglycemic rats (n = 9). Cerebral blood flow did not differ between these two groups in any region. Thus hyperglycemia reduced the extent of ischemic depolarization within the cortex during the first 30 minutes of focal cerebral ischemia. This effect may be related to the increased tissue acidosis or to other factors that may lessen calcium influx and preserve cellular energy stores in the ischemic cortex of the hyperglycemic rats.


2004 ◽  
Vol 24 (6) ◽  
pp. 668-676 ◽  
Author(s):  
Hiroharu Kataoka ◽  
Seong-Woong Kim ◽  
Nikolaus Plesnila

The contribution of leukocyte infiltration to brain damage after permanent focal cerebral ischemia and the underlying molecular mechanisms are still unclear. Therefore, the aim of this study was to establish a mouse model for the visualization of leukocytes in the cerebral microcirculation in vivo and to investigate leukocyte-endothelial interaction (LEI) after permanent middle cerebral artery occlusion (MCAO). Sham-operated 129/Sv mice showed physiologic LEI in pial venules as observed by intravital fluorescent microscopy. Permanent focal cerebral ischemia induced a significant increase of LEI predominantly in pial venules. The number of rolling and adherent leukocytes reached 36.5 ± 13.2/100 μm × min and 22.5 ± 7.9/100 μm × min, respectively at 120 minutes after MCAO ( P = 0.016 vs. control). Of note, rolling and adherent leukocytes were also observed in arterioles of ischemic animals (7.3 ± 3.0/100 μm × min rolling and 3.0 ± 3.6/100 μm × min adherent). Capillary density was not different between groups. These results demonstrate that leukocytes accumulate in the brain not only after transient but also after permanent focal cerebral ischemia and may therefore contribute to brain damage after stroke without reperfusion.


2007 ◽  
Vol 28 (4) ◽  
pp. 812-823 ◽  
Author(s):  
Richard Milner ◽  
Stephanie Hung ◽  
Xiaoyun Wang ◽  
Maria Spatz ◽  
Gregory J del Zoppo

During focal cerebral ischemia, the detachment of astrocytes from the microvascular basal lamina is not completely explained by known integrin receptor expression changes. Here, the impact of experimental ischemia (oxygen—glucose deprivation (OGD)) on dystroglycan expression by murine endothelial cells and astrocytes grown on vascular matrix laminin, perlecan, or collagen and the impact of middle cerebral artery occlusion on αβ-dystroglycan within cerebral microvessels of the nonhuman primate were examined. Dystroglycan was expressed on all cerebral microvessels in cortical gray and white matter, and the striatum. Astrocyte adhesion to basal lamina proteins was managed in part by α-dystroglycan, while ischemia significantly reduced expression of dystroglycan both in vivo and in vitro. Furthermore, dystroglycan and integrin α6β4 expressions on astrocyte end-feet decreased in parallel both in vivo and in vitro. The rapid loss of astrocyte dystroglycan during OGD appears protease-dependent, involving an matrix metalloproteinase-like activity. This may explain the rapid detachment of astrocytes from the microvascular basal lamina during ischemic injury, which could contribute to significant changes in microvascular integrity.


2013 ◽  
Vol 33 (12) ◽  
pp. 1967-1975 ◽  
Author(s):  
Abraham Martín ◽  
Boguslaw Szczupak ◽  
Vanessa Gómez-Vallejo ◽  
Sandra Plaza ◽  
Daniel Padró ◽  
...  

The use of selective serotonin reuptake inhibitors has shown functional improvement after stroke. Despite this, the role of serotoninergic neurotransmission after cerebral ischemia evolution and its involvement in functional recovery processes are still largely unknown. For this purpose, we performed in parallel in vivo magnetic resonance imaging and positron emission tomography (PET) with [11C]DASB and [18F]altanserin at 1, 3, 7, 14, 21, and 28 days after middle cerebral artery occlusion (MCAO) in rats. In the ischemic territory, PET with [11C]DASB and [18F]altanserin showed a dramatic decline in serotonin transporter (SERT) and 5-HT2A binding potential in the cortex and striatum after cerebral ischemia. Interestingly, a slight increase in [11C]DASB binding was observed from days 7 to 21 followed by the uppermost binding at day 28 in the ipsilateral midbrain. In contrast, no changes were observed in the contralateral hemisphere by using both radiotracers. Likewise, both functional and behavior testing showed major impaired outcome at day 1 after ischemia onset followed by a recovery of the sensorimotor function and dexterity from day 21 to day 28 after cerebral ischemia. Taken together, these results might evidence that SERT changes in the midbrain could have a key role in the functional recovery process after cerebral ischemia.


1997 ◽  
Vol 17 (5) ◽  
pp. 500-506 ◽  
Author(s):  
Wolf-R. Schäbitz ◽  
Stefan Schwab ◽  
Matthias Spranger ◽  
Werner Hacke

Brain-derived neurotrophic factor (BDNF), acting through the high-affinity receptor tyrosine kinase (TrkB), is widely distributed throughout the central nervous system and displays in vitro trophic effects on a wide range of neuronal cells, including hippocampal, cerebellar, and cortical neurons. In vivo, BDNF rescues motorneurons, hippocampal, and substantia nigral dopaminergic cells from traumatic and toxic brain injury. After transient middle cerebral artery occlusion (MCAO), upregulation of BDNF-mRNA in cortical neurons suggests that BDNF potentially plays a neuroprotective role in focal cerebral ischemia. In the current study, BDNF (2.1 μg/d) in vehicle or vehicle alone (controls) was delivered intraventricularly for 8 days, beginning 24 hours before permanent middle cerebral artery occlusion by intraluminal suture in Wistar rats (n = 13 per group). There were no differences in physiological variables recorded during surgery for the two groups. Neurological deficit (0 to 4 scale), which was assessed on a daily basis, improved in BDNF-treated animals compared with controls ( P < 0.05; analysis of variance and Scheffe's test). There were no significant differences in weight in BDNF-treated animals and controls during the experiment. After elective killing on day 7 after MCAO, brains underwent 2,3,5-triphenyltetrazolium chloride staining for calculation of the infarct volume and for histology (hematoxylin and eosin and glial fibrillary acid protein). The mean total infarct volume was 83.1 ± 27.1 mm3 in BDNF-treated animals and 139.2 ± 56.4 mm3 in controls (mean ± SD; P < 0.01, unpaired, two-tailed t-test). The cortical infarct volume was 10.8 ± 7.1 mm3 in BDNF-treated animals and 37.9 ± 19.8 mm3 in controls (mean ± SD; P < 0.05; unpaired, two-tailed t-test), whereas ischemic lesion volume in caudoputaminal infarction was not significantly different. These results show that pretreatment with intraventricular BDNF reduces infarct size after focal cerebral ischemia in rats and support the hypothesis of a neuroprotective role for BDNF in stoke.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jiao Y ◽  
◽  
Wang J ◽  

Objectives: The present study aims to investigate the effect of Limb Remote Ischemic Preconditioning (LRIP) on the expression of Nogo-A and PirB in the cortex of mice with focal cerebral ischemia, and related pathways involving in axonal regeneration and neurological function recovery after cerebral ischemia. Methods: Adult male C57/BL6 mice were divided into sham-operated (sham), transient Middle Cerebral Artery Occlusion (MCAO), LRIP and anti- PirBAb treatment group. Samples were collected 48h after cerebral ischemia. The histopathologic changes were assessed by 1,3,5-Triphenyl-2H-Tetrazolium Chloride (TTC), and Hematoxylin and Eosin (HE) staining and TUNEL method. The expression of Nogo-A and PirB were determined by immunofluorescence, RT-PCR and Western blot respectively. Results: TTC staining showed that LRIP treatment reduced the infarct size of mice and anti-PirBAb treatment further decline the infarct size, which was accompanied with the decline of neurological deficit score and reduction of neuronal damage. LRIP treatment also reduced the TUNEL positive cells induced by MCAO and anti-PirBAb treatment further strengthened the effect of LRIP. Except sham group, the expressions of Nogo-A and PirB in other three groups all increased with varying degrees, among which MCAO group was the highest, LRIP group was the second and the anti-PirBAb group was the lowest. The expressions of growth associated protein 43 (GAP43) showed opposite tendency. Conclusions: LRIP plays beneficial influence on cerebral ischemia. LRIP and PirB inhibition combination has a better protective effect on nervous system after cerebral ischemia in mice.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Ludmila Belayev ◽  
Sung-Ha Hong ◽  
Pranab K Mukherjee ◽  
Hemant Menghani ◽  
Larissa Khoutorova ◽  
...  

Introduction: Mesencephalic astrocyte-derived neurotrophic factor (MANF) has been identified as a secretion protein, which biases immune cells toward an anti-inflammatory phenotype, thereby promoting tissue repair after various injuries to neurons in vivo or in vitro. However, the function of MANF during and after brain ischemia is still not known. The purpose of our study was to examine the characteristics and implication of MANF expression induced by focal cerebral ischemia. In addition we investigated if docosahexaenoic acid (DHA) potentiates MANF mRNA expression and provides additional neuroprotection. Methods: Male SD (280-320) rats were anesthetized with isoflurane and subjected to 2 h of middle cerebral artery occlusion (MCAo) by intraluminal suture. DHA (5 mg/kg; n=13) or vehicle (saline; n=8) was administered IV at 3 h after the onset of MCAo. Neurological function was evaluated during occlusion (60 min) and on days 1, 3 and 7 after MCAo. MANF mRNA expression, protein levels, and apoptosis were measured by immunohistochemistry and Western blotting. Results: Behavioral deficit was significantly improved by treatment with DHA compared to vehicle on days 1, 3 and 7. MANF was found to be extremely upregulated in the ischemic penumbra. The expression of MANF was neuronal in the cortex and dentate gyrus. DHA administration significantly increased the number of MANF + /NeuN + cells in the cortex (by 76.6 %) and dentate gyrus (by 20.5 %) compared to saline-treated animals. The number of MANF/NeuN-positive cells was not different in the subcortex, CA1 and CA3 regions between DHA- and saline-treated groups. Treatment with DHA increased MANF + /GFAP + cells in the subcortex (by 27.7 %) and dentate gyrus (by 38.0 %) compared to the vehicle-treated brains. Total and cortical infarct volumes were attenuated by DHA treatment by 48 % and by 73 % compared to vehicle treatment at 24 h after MCAo. Conclusion: MANF mRNA expression and protein levels are increased after focal cerebral ischemia. It was found to be extremely upregulated in the ischemic penumbra and dentate gyrus. The expression of MANF was mostly neuronal and astrocytic. DHA potentiates MANF expression and provides additional neuroprotection.


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