scholarly journals Neuroprotective Effect of Chronic Intracranial Toxoplasma gondii Infection in a Mouse Cerebral Ischemia Model

2020 ◽  
Vol 58 (4) ◽  
pp. 461-466
Author(s):  
Seung Hak Lee ◽  
Bong-Kwang Jung ◽  
Hyemi Song ◽  
Han Gil Seo ◽  
Jong-Yil Chai ◽  
...  

Toxoplasma gondii is an obligate intracellular protozoan parasite that can invade various organs in the host body, including the central nervous system. Chronic intracranial T. gondii is known to be associated with neuroprotection against neurodegenerative diseases through interaction with host brain cells in various ways. The present study investigated the neuroprotective effects of chronic T. gondii infection in mice with cerebral ischemia experimentally produced by middle cerebral artery occlusion (MCAO) surgery. The neurobehavioral effects of cerebral ischemia were assessed by measurement of Garcia score and Rotarod behavior tests. The volume of brain ischemia was measured by triphenyltetrazolium chloride staining. The expression levels of related genes and proteins were determined. After cerebral ischemia, corrected infarction volume was significantly reduced in T. gondii infected mice, and their neurobehavioral function was significantly better than that of the uninfection control group. Chronic T. gondii infection induced the expression of hypoxia-inducible factor 1-alpha (HIF-1α) in the brain before MCAO. T. gondii infection also increased the expression of vascular endothelial growth factor after the cerebral ischemia. It is suggested that chronic intracerebral infection of T. gondii may be a potential preconditioning strategy to reduce neural deficits associated with cerebral ischemia and induce brain ischemic tolerance through the regulation of HIF-1α expression.

2021 ◽  
Author(s):  
Lixia Zhang ◽  
Yulong Ma ◽  
Min Liu ◽  
Miao Sun ◽  
Jin Wang ◽  
...  

Abstract Growing evidence indicates that estrogen plays a pivotal role in neuroprotection against cerebral ischemia, but the molecular mechanism of this protection is still elusive. N-myc downstream‐regulated gene 2 (Ndrg2), an estrogen-targeted gene, has been shown to exert neuroprotective effects against cerebral ischemia in male mice. However, the role of Ndrg2 in the neuroprotective effect of estrogen remains unknown. In this study, we first detected NDRG2 expression levels in the cortex and striatum in both female and male mice with western blot analyses. We then detected cerebral ischemic injury by constructing middle cerebral artery occlusion and reperfusion (MCAO-R) models in Ndrg2 knockout or conditional knockdown female mice. We further implemented estrogen, ERα or ERβ agonist replacement in the ovariectomized (OVX) Ndrg2 knockouts or conditional knockdowns female mice, then tested for NDRG2 expression, glial fibrillary acidic protein (GFAP) expression, and extent of cerebral ischemic injury. We found that NDRG2 expression was significantly higher in female than in male mice in both the cortex and striatum. Ndrg2 knockouts and conditional knockdowns showed significantly aggravated cerebral ischemic injury in female mice. Estrogen and ERβ replacement treatment (DPN) led to NDRG2 upregulation in both the cortex and striatum of OVX mice. Estrogen and DPN also led to GFAP upregulation in OVX mice. However, the effect of estrogen and DPN in activating astrocytes was lost in Ndrg2 knockouts OVX mice and primary cultured astrocytes, but partially retained in conditional knockdowns OVX mice. Most importantly, we found that the neuroprotective effects of E2 and DPN against cerebral ischemic injury were lost in Ndrg2 knockouts OVX mice but partially retained in conditional knockdowns OVX mice. These findings demonstrate that estrogen alleviated cerebral ischemic injury via ERβ upregulation of Ndrg2, which could activate astrocytes, indicating that Ndrg2 is a critical mediator of E2-induced neuroprotection against cerebral ischemic injury.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Yang Yang ◽  
Keqiang Gao ◽  
Zhiying Hu ◽  
Weiyun Li ◽  
Henry Davies ◽  
...  

It has previously been demonstrated that ischemic stroke activates autophagy pathways; however, the mechanism remains unclear. The aim of this study is to further investigate the role that autophagy plays in cerebral ischemia. 2, 4-diamino-6-hydroxy-pyrimidine (DAHP), for its nitric oxide synthase (NOS) inhibiting neuroprotective effect, and triptolide (TP), for its anti-inflammatory property, were selected to administer pre middle cerebral artery occlusion (MCAO). The drugs were administered 12 hours prior to MCAO. Both magnetic resonance imaging (MRI) and 2, 3, 5-triphenyltetrazolium chloride (TTC) staining showed that the drugs reduce the area of infarction. Immunoblotting analysis revealed increases in Beclin-1 and myeloid cell leukelia-1(Mcl-1) in treated rats. This could be a contributing factor to the reduction in autophagy induced damage. Immunochemistry and western blot showed that mTOR expression in treated rats was marginally different 24 h after injury, and this could also be significant in the mechanism. Furthermore, terminal deoxynucleotidyl transferase- (TdT-) mediated dUTP nick end labeling (TUNEL) staining proved that the drugs are effective in reducing apoptosis. The upregulation of Beclin-1 and Mcl-1 and downregulation of Bcl-2, caspase-3, and the Bcl-2/Beclin-1 ratio infer that the neuroprotective effect of DAHP and TP act via the mediation of autophagy and apoptosis pathways.


2021 ◽  
Vol 12 ◽  
Author(s):  
Li Yu ◽  
Yangyang Zhang ◽  
Xixi Zhao ◽  
Haitong Wan ◽  
Yu He ◽  
...  

Guhong injection (GHI) is a drug for ischemic stroke created by combining safflower, a traditional Chinese medicine, and aceglutamide, a Western medicine. In this study, we investigated the curative effect of GHI on cerebral ischemia–reperfusion (I/R) injury via the PKC/HIF-1α pathway in rats. Adult male Sprague Dawley rats were randomly divided into seven groups: sham-operated, middle cerebral artery occlusion (MCAO), GHI, nimodipine injection (NMDP), MCAO + LY317615 (PKC inhibitor), GHI + LY317615, and NMDP + LY317615. After establishing an MCAO rat model, we performed neurological deficit testing, 2,3,5-triphenyltetrazolium chloride staining, hematoxylin and eosin (HE) staining, enzyme-linked immunosorbent assay, Western blotting, and q-PCR to detect the brain damage in rats. Compared with the MCAO group, the GHI and GHI + LY317615 group showed neurological damage amelioration as well as decreases in serum hypoxia-inducible factor-1α (HIF-1α), protein kinase C (PKC), and erythropoietin levels; brain HIF-1α and inducible nitric oxide synthase protein expression; and brain HIF-1α and NOX-4 mRNA expression. These effects were similar to those in the positive control groups NMDP and NMDP + LY317615. Thus, our results confirmed GHI can ameliorate cerebral I/R injury in MCAO rats possibly via the PKC/HIF-1α pathway.


1997 ◽  
Vol 17 (11) ◽  
pp. 1137-1142 ◽  
Author(s):  
Kazushi Takahashi ◽  
Joel H. Greenberg ◽  
Paul Jackson ◽  
Keith Maclin ◽  
Jie Zhang

Poly(adenosine 5′-diphosphoribose) synthetase (PARS) has been described as an important candidate for mediation of neurotoxicity by nitric oxide. In the current study, we demonstrate for the first time that in vivo administration of a potent PARS inhibitor, 3,4-dihydro 5-[4-1(1-piperidinyl) butoxy]-1(2H)-isoquinolinone, leads to a significant reduction of infarct volume in a focal cerebral ischemia model in the rat. Focal cerebral ischemia was produced by cauterization of the right distal middle cerebral artery (MCA) with bilateral temporary common carotid artery occlusion for 90 minutes. 3,4-Dihydro 5[4-(1-piperidinyl) butoxy]-1(2H)-isoquinolinone was dissolved in dimethyl sulfoxide and injected intraperitoneally. Animals were treated 2 hours before MCA occlusion (control, n = 14; 5 mg/kg, n = 7; 10 mg/kg, n = 7; 20 mg/kg, n = 7; 40 mg/kg, n = 7), and 2 hours after MCA occlusion (same doses as before treatment). Twenty-four hours after MCA occlusion, the total infarct volume was measured using 2,3,5-triphenyltetrazolium chloride. Inhibition of PARS leads to a significant decrease in the damaged volume in the 5 mg/kg–treated group (106.7 ± 23.2 mm3; mean ± SD, P < 0.002), the 10 mg/kg–treated group (76.4 ± 16.8 mm3, P < 0.001), and the 20 mg/kg–treated group (110.2 ± 42.0 mm3, P < 0.02) compared with the control group (165.2 ± 34.0 mm3). The substantial reduction in infarct volume indicates that the activation of PARS may play an important role in the pathogenesis of brain damage in cerebral ischemia through intracellular energy depletion.


2011 ◽  
Vol 114 (2) ◽  
pp. 340-354 ◽  
Author(s):  
Li-bang Yuan ◽  
Hai-long Dong ◽  
Hao-Peng Zhang ◽  
Rui-ni Zhao ◽  
Gu Gong ◽  
...  

Background Recent studies suggest that the novel neuropeptide orexin-A may play an essential role during neuronal damage. However, the function of orexin-A during brain ischemia remains unclear. Recently, hypoxia-inducible factor-1α (HIF-1α) was shown to be activated by orexin-A. The aim of the current study is to test the hypothesis that administration of exogenous orexin-A can attenuate ischemia-reperfusion injury through the facilitation of HIF-1α expression. Methods Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion for 120 min. Rats were treated with different doses of orexin-A or vehicle before the ischemia and at the onset of reperfusion. To investigate the action of HIF-1α in the neuroprotective effects of orexin-A, the HIF-1α inhibitor YC-1 was used alone or combined with orexin-A. Neurologic deficit scores and infarct volume were assessed. Brains were harvested for immunohistochemical staining and western blot analysis. Results Orexin-A significantly ameliorated neurologic deficit scores and reduced infarct volume after cerebral ischemia reperfusion. Administration of 30 μg/kg orexin-A showed optimal neuroprotective effects. This effect was still present 7 days after reperfusion. Furthermore, orexin-A decreased the number of apoptotic cells and significantly enhanced HIF-1α expression after cerebral ischemia reperfusion. Moreover, the facilitation of HIF-1α expression was accompanied with inhibition of von Hippel-Lindau expression. Administration of HIF-1α inhibitor suppressed the increase of HIF-1α and reversed the neuroprotective effects of orexin-A. Conclusions Orexin-A has a neuroprotective effect against cerebral ischemia-reperfusion injury. These effects may be mediated through the HIF-1α pathway.


Author(s):  
Zahra Esfandiari ◽  
Mohammad Amin Edalatmanesh

Introduction: Uteroplacental insufficiency (UPI) causes neurodevelopmental deficits affecting the intrauterine growth restricted (IUGR) offspring. This study aimed to analyze the effects of Gallic acid (GA) on memory deficit and brain-derived neurotrophic factor (BDNF) content in entorhinal cortex of UPI rat models. Methods: In this experimental study, 40 pregnant Wistar rats were randomly divided into 5 groups, including: control, UPI, UPI+GA100, UPI+GA200and UPI+GA400. For IUGR induction, anterior uterine artery occlusion surgery was carried out on gestation day (GD) 18. From GD15, GA was administrated orally, in 100, 200 and 400 mg/kg BW doses until the birth of their neonates. Spatial and working memories are analyzed by Morris water maze and Y maze at postnatal day (PND) 30, respectively. Then, BDNF cerebral cortex level was estimated using ELISA technique.The data were analyzed through ANOVA and Tukey Post hoc in SPSS software version 16. Results: A significant decrease was observed in spatial and working memories and BDNF content in entorhinal cortex of UPI group in comparison with the control group (p˂0.05). On the other hand, GA-treated groups showed a significant increase in BDNF content and amelioration of spatial and working memories (p˂0.05). Conclusion: Fetal growth restrictionafter UPI by decreasingBDNFlevel in entorhinal cortex caused memory deficits in rat’s model. Moreover, neuroprotective effects of GA lead to increased BDNF content and ameliorate cognitive deficits in UPI model.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7849 ◽  
Author(s):  
Hiromitsu Kunimi ◽  
Yukihiro Miwa ◽  
Yusaku Katada ◽  
Kazuo Tsubota ◽  
Toshihide Kurihara

Purpose The therapeutic approach for retinal ganglion cell (RGC) degeneration has not been fully established. Recently, it has been reported that hypoxia-inducible factor (HIF) may be involved with retinal neurodegeneration. In this study, we investigated neuroprotective effects of a HIF inhibitor against RGC degeneration induced in a murine model of retinal ischemia-reperfusion (I/R). Methods Eight-weeks-old male C57/BL6J mice were treated with intraperitoneal injection of a HIF inhibitor topotecan (1.25 mg/kg) for 14 days followed by a retinal I/R procedure. Seven days after the I/R injury, the therapeutic effect was evaluated histologically and electrophysiologically. Results The increase of HIF-1α expression and the decrease of retinal thickness and RGC number in I/R were significantly suppressed by administration of topotecan. Impaired visual function in I/R was improved by topotecan evaluated with electroretinogram and visual evoked potentials. Conclusions Topotecan administration suppressed HIF-1a expression and improved RGC survival resulting in a functional protection against retinal I/R. These data indicated that the HIF inhibitor topotecan may have therapeutic potentials for RGC degeneration induced with retinal ischemia or high intraocular pressure.


2021 ◽  
Author(s):  
Taotao Lu ◽  
Huihong Li ◽  
Yangjie Zhou ◽  
Wei Wei ◽  
Linlin Ding ◽  
...  

Abstract BackgroundNeuroinflammation and apoptosis are involved in the pathogenesis of ischemic stroke. Alisol A 24-acetate (24A) has a strong inhibitory effect on inflammation and cell apoptosis. The neuroprotective effect of 24A in the global cerebral ischemia/ reperfusion (GCI/R) is still unclear. Methods GCI/R mice was used to investigated the neuroprotective effect of 24A. Modified neurological deficit scores, Morris Water Maze and object recognition test were used to evaluate behaviors. The metabolism in brain regions was detected by MRS. The changes of microglia, astrocytes and neurons was detected. The inflammation and apoptosis were measured.Results The results showed that 24A improved behavioral dysfunction and brain metabolism, alleviate neuroinflammation and apoptosis, inhibited microglia and astrocytes activation, which is associated with the activation of PI3K/AKT pathway. ConclusionsTaken together, our study demonstrated that 24A could alleviate GCI/R injury through anti-neuroinflammation and anti-apoptosis via regulating the PI3K/AKT pathway.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
George Wong ◽  

Background and purpose: Disability is common after severe stroke resulting from major cerebral artery occlusion despite adoption of prophylactic decompressive craniectomy. Experimental mesenchymal stem cell treatments are commonly administrated through systemic infusion, with limitations in dosage. In this study, the neuro-modulation effect of topical mesenchymal stem cells (MSCs) was tested in a rodent middle carotid artery occlusion (MCAO) model. Methods: Twenty-four hours after MCAO, craniotomy was made and 0.8 x 10 6 GFP-MSCs were topically applied to the ipsilateral parietal cortex (N=30). In the control group, saline were topically applied to the ipsilateral parietal cortex (N=30). Results: After topical MSC treatment, neurological assessments with Rotarod test (at days 3, 7, and 10) and Morris Water Maze test (at days 3, 7, and 14) were significantly better, as compared to the control group; the infarct volume was also smaller. MSCs were found in the penumbra of the infarct 3 days after topical application. In the PCR array analysis of the RNA extracted from penumbra cortex, topical application of MSCs changed 10 gene expressions in the penumbra at day 3 (fold change >1.25, p<0.05 after Bonferroni corrections for multiple comparisons). The seven up-regulated genes (Apoe, Ascl1, Efnb1, Mef2c,Nog,S100a6, B2m) involve neuronal migration, neuronal differentiation, neuronal cell fate determination, regulation of synaptic plasticity, axonogensis;, growth factors, and cell adhesion. Pax2, Pax3 and Th were downregulated. Pax2 and Pax3 are related to apoptosis. Both Apoe and Thl involve synaptic transmission. Conclusions: Topically applied MSCs reduced cerebral infarction volume and improved the neurological function from cerebral ischemia resulting from a major cerebral artery occlusion in a rodent experimental model.


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