scholarly journals Mir-184 Contributes to Brain Injury Through Targeting PPAP2B Following Ischemic Stroke in Male Rats

2021 ◽  
Vol 14 ◽  
Author(s):  
Huajun Yang ◽  
Yifan Zhang ◽  
Hongqun Chen ◽  
Yingwu Zhu ◽  
Yuan Li ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Infarct Volume ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Cerebral Infarct ◽  
Male Rats ◽  
Luciferase Reporter ◽  
Pcr Analysis

Our previous study revealed that miR-184 expression is significantly altered in the brain following ischemic stroke in rats. However, it is unknown whether this alteration in miR-184 expression contributes to brain injury after ischemic stroke. Here, we aim to address the potential of miR-184 to impact nerve injury following ischemia and reperfusion. Rats received ICV injection of miR-184 adenovirus or empty vector and were subjected to right middle cerebral artery occlusion (MCAO) to establish an ischemic stroke model. We cultured SH-SY5Y cells under oxygen-glucose deprivation/reoxygenation (OGD/R) and transfected them with miR-184 lentivirus to explore the primary mechanisms. To evaluate miR-184 expression, neurological function deficits, the cerebral infarct volume, cell viability, and apoptosis, qRT-PCR analysis of miR-184 expression, the modified neurological severity score (mNSS) system, TTC staining, the CCK-8 assay, flow cytometry, and dual-luciferase reporter assays were utilized. We found that miR-184 expression was downregulated and that the cerebral infarct volume and mNSSs were increased following ischemic stroke; however, increasing the level of miR-184 alleviated brain damage. Overexpression of miR-184 resulted in increased viability and reduced apoptosis of SH-SY5Y cells following OGD/R in vitro. We identified the phosphatidic acid phosphatase type 2B (PPAP2B) gene as a direct target gene of miR-184. In summary, our results reveal that attenuation of miR-184 levels in ischemic stroke contributes to ischemic injury through targeting PPAP2B mRNA-mediated apoptosis, which may be a promising therapeutic target for ischemic stroke.

Neuroprotective Effects of microRNA-140-5p on Ischemic Stroke in Mice via its Regulation on the TLR4/NF-κB Axis

2020 ◽  
Author(s):  
Song Wenjun ◽  
Tiancheng Wang ◽  
Bei Shi ◽  
Zhijun Wu ◽  
Wenjie Wang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Luciferase Reporter ◽  
Tunel Staining ◽  
Related Factors ◽  
Neuroprotective Effects ◽  
High Level

Abstract Background and aim: Ischemic stroke is one of the main causes of death worldwide and permanent global disability. On the basis of existing literature data, we carried out studies in an effort to explore how miR-140-5p affects ischemic stroke and whether the mechanism relates to toll-like receptor-4 (TLR4) and nuclear factor-kappa B (NF-κB).Methods: Middle cerebral artery occlusion (MCAO) was employed to establish a mouse model of ischemic stroke in vivo, while primary neurons were exposed to oxygen-glucose deprivation (OGD) to set up an ischemic stroke model in vitro. RT-qPCR was performed to detect the miR-140-5p expression and Western blot was employed to detect the expression TLR4, NF-κB, and apoptosis-related factors. Then, based gain-function of experiments using miR-140-5p mimic and TLR4 overexpression plasmid, neurological function score, TTC staining, TUNEL staining, as well as flow cytometry were carried out to evaluate the effects of miR-140-5p and TLR4 on MCAO mice and OGD neurons. Meanwhile, dual-luciferase reporter assay was used to validate the relationship between miR-140-5p and TLR4.Results: miR-140-5p expressed at a low level and TLR4 at a high level in ischemic stroke. It was verified that miR-140-5p targeted TLR4 and downregulated its expression. miR-140-5p overexpression was observed to inhibit the apoptosis of neurons under OGD exposure and restrain the progression of ischemic stroke, while TLR4 overexpression promoted the apoptosis and disease progression. Besides, miR-140-5p overexpression led to a decrease in NF-κB protein level, which was increased by TLR4 overexpression. Conclusion: In conclusion, from our data we conclude that miR-140-5p overexpression may be instrumental for the therapeutic targeting of ischemic stroke by alleviating neuron injury with the involvement of TLR4/NF-κB axis.

scholarly journals Modulator of apoptosis-1 is a potential therapeutic target in acute ischemic injury

2018 ◽  
Vol 39 (12) ◽  
pp. 2406-2418 ◽  
Author(s):  
Su Jing Chan ◽  
Hui Zhao ◽  
Kazuhide Hayakawa ◽  
Chou Chai ◽  
Chong Teik Tan ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Infarct Volume ◽  
Neuronal Loss ◽  
Ischemic Injury ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
In Vivo Models ◽  
The Brain

Modulator of apoptosis 1 (MOAP-1) is a Bax-associating protein highly enriched in the brain. In this study, we examined the role of MOAP-1 in promoting ischemic injuries following a stroke by investigating the consequences of MOAP-1 overexpression or deficiency in in vitro and in vivo models of ischemic stroke. MOAP-1 overexpressing SH-SY5Y cells showed significantly lower cell viability following oxygen and glucose deprivation (OGD) treatment when compared to control cells. Consistently, MOAP-1−/− primary cortical neurons were observed to be more resistant against OGD treatment than the MOAP-1+/+ primary neurons. In the mouse transient middle cerebral artery occlusion (tMCAO) model, ischemia triggered MOAP-1/Bax association, suggested activation of the MOAP-1-dependent apoptotic cascade. MOAP-1−/− mice were found to exhibit reduced neuronal loss and smaller infarct volume 24 h after tMCAO when compared to MOAP-1+/+ mice. Correspondingly, MOAP-1−/− mice also showed better integrity of neurological functions as demonstrated by their performance in the rotarod test. Therefore, both in vitro and in vivo data presented strongly support the conclusion that MOAP-1 is an important apoptotic modulator in ischemic injury. These results may suggest that a reduction of MOAP-1 function in the brain could be a potential therapeutic approach in the treatment of acute stroke.

scholarly journals Dectin-1/Syk signaling triggers neuroinflammation after ischemic stroke in mice

2019 ◽  
Author(s):  
Xin-chun Ye ◽  
Qi Hao ◽  
Wei-jing Ma ◽  
Qiu-chen Zhao ◽  
Wei-wei Wang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Infarct Volume ◽  
Inos Expression ◽  
Microglial Cells ◽  
Brain Infarct ◽  
Tnf Α ◽  
Bv2 Microglial Cells ◽  
The Brain

Abstract Dendritic cell-associated C-type lectin-1 (Dectin-1) receptor has been reported to be involved in neuroinflammation in Alzheimer's disease and traumatic brain injury. The present study was designed to investigate the role of Dectin-1 and its downstream target spleen tyrosine kinase (Syk) in early brain injury after ischemic stroke using a focal cortex ischemic stroke model. Adult male C57BL/6J mice were subjected to a cerebral focal ischemia model of ischemic stroke. The neurological score, adhesive removal test and foot-fault test were evaluated on days 1, 3, 5 and 7 after ischemic stroke. Dectin-1, Syk, phosphorylated (p)-Syk, tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) expression was analyzed via western blotting in ischemic brain tissue after ischemic stroke and in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro. The brain infarct volume and Iba1-positive cells were evaluated using Nissl’s and immunofluorescence staining, respectively. The Dectin-1 antagonist laminarin (LAM) and a selective inhibitor of Syk phosphorylation (piceatannol; PIC) were used for the intervention. Dectin-1, Syk, and p-Syk expression was significantly enhanced on days 3, 5 and 7 and peaked on day 3 after ischemic stroke. The Dectin-1 antagonist LAM or Syk inhibitor PIC decreased the number of Iba1-positive cells and TNF-α and iNOS expression, decreased the brain infarct volume and improved neurological functions on day 3 after ischemic stroke. In addition, the in vitro data revealed that Dectin-1, Syk and p-Syk expression was increased following the 3-h OGD and 0, 3 and 6 h of reperfusion in BV2 microglial cells. LAM and PIC also decreased TNF-α and iNOS expression 3 h after OGD/R induction. Dectin-1/Syk signaling plays a crucial role in inflammatory activation after ischemic stroke, and further investigation of Dectin-1/Syk signaling in stroke is warranted.

scholarly journals Ras-like Gem GTPase induced by Npas4 promotes activity-dependent neuronal tolerance for ischemic stroke

2021 ◽  
Vol 118 (32) ◽  
pp. e2018850118
Author(s):  
Hiroo Takahashi ◽  
Ryo Asahina ◽  
Masayuki Fujioka ◽  
Takeshi K. Matsui ◽  
Shigeki Kato ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cortical Neurons ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Small Gtpase ◽  
Neuroprotective Effects ◽  
Necessary And Sufficient ◽  
Activity Dependent

Ischemic stroke, which results in loss of neurological function, initiates a complex cascade of pathological events in the brain, largely driven by excitotoxic Ca2+ influx in neurons. This leads to cortical spreading depolarization, which induces expression of genes involved in both neuronal death and survival; yet, the functions of these genes remain poorly understood. Here, we profiled gene expression changes that are common to ischemia (modeled by middle cerebral artery occlusion [MCAO]) and to experience-dependent activation (modeled by exposure to an enriched environment [EE]), which also induces Ca2+ transients that trigger transcriptional programs. We found that the activity-dependent transcription factor Npas4 was up-regulated under MCAO and EE conditions and that transient activation of cortical neurons in the healthy brain by the EE decreased cell death after stroke. Furthermore, both MCAO in vivo and oxygen-glucose deprivation in vitro revealed that Npas4 is necessary and sufficient for neuroprotection. We also found that this protection involves the inhibition of L-type voltage-gated Ca2+ channels (VGCCs). Next, our systematic search for Npas4-downstream genes identified Gem, which encodes a Ras-related small GTPase that mediates neuroprotective effects of Npas4. Gem suppresses the membrane localization of L-type VGCCs to inhibit excess Ca2+ influx, thereby protecting neurons from excitotoxic death after in vitro and in vivo ischemia. Collectively, our findings indicate that Gem expression via Npas4 is necessary and sufficient to promote neuroprotection in the injured brain. Importantly, Gem is also induced in human cerebral organoids cultured under an ischemic condition, revealing Gem as a new target for drug discovery.

1,8-cineole ameliorates ischaemic brain damage via TRPC6/CREB pathways in rats

2021 ◽  
Author(s):  
Chen Meng ◽  
Wenjing Zeng ◽  
Jing Lv ◽  
Yu Wang ◽  
Meiling Gao ◽  
...  
Keyword(s):  
Brain Damage ◽  
Transient Receptor Potential ◽  
Infarct Volume ◽  
Glucose Deprivation ◽  
Neurological Dysfunction ◽  
Male Rats ◽  
Neuroprotective Effects ◽  
Ischaemic Brain

Abstract Objectives A previous in vitro study reported that the monoterpene oxide 1,8-cineole (cineole) attenuates neuronal caused by oxygen–glucose deprivation/reoxygenation in culture. However, to date, there is no in vivo evidence showing neuroprotective effects of cineole against stroke. This study aimed to investigate whether cineole attenuates cerebral ischaemic damage in rats. Methods A rat model of middle cerebral artery occlusion (MCAO) followed by 24 h reperfusion was applied. Male rats were treated with oral cineole (100 mg/kg) for 7 consecutive days, then subjected to MCAO surgery. Infarct volume, neurologic deficits, apoptosis and expression levels of all-spectrin breakdown products of 145 kDa (SBDP145), transient receptor potential canonical (subtype) 6 (TRPC6) and phosphorylated CREB (p-CREB) were measured in ischaemic brain tissues. Key findings Cineole treatment significantly reduced infarct volume, neurological dysfunction, neuronal apoptosis, SBDP145 formation and TRPC6 degradation and enhanced p-CREB expression in MCAO rats compared with vehicle treatment. These neuroprotective effects were markedly suppressed by pharmacological inhibition of MEK or CaMKIV signalling. Conclusions Our study provides in vivo evidence demonstrating that cineole pretreatment attenuates ischaemic stroke-induced brain damage, mainly through blocking calpain-induced TRPC6 degradation and activating CREB via MEK/CREB and CaMKIV/CREB signalling pathways.

Abstract 44: Hdac3i Alleviated Ischemic Stroke Injury Through Modulating Aim2 Inflammasome and Microglia Polarization

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Meijuan Zhang ◽  
Mingxu Xia ◽  
Qiuchen Zhao ◽  
Yun Xu
Keyword(s):  
Ischemic Stroke ◽  
Infarct Volume ◽  
Glucose Deprivation ◽  
Vehicle Group ◽  
Triphenyltetrazolium Chloride ◽  
Bv2 Cells ◽  
Severity Scores ◽  
Microglia Polarization

Background: Inflammasome in microglia are critical to elicit inflammatory cascades in ischemic stroke. Histone deacetylases 3 (HDAC3) regulate acetylation states of histone and non-histone proteins and could be a powerful regulator of inflammatory process in stroke. Methods: Primary microglia, BV2 cells subjected to oxygen glucose deprivation (OGD) or LPS stimulation were applied to mimic inflammatory response in vitro . Middle cerebral artery occlusion (MCAO) model were applied to mimic acute stroke in vivo . Ischemic infarct volume and neurological functions were evaluated through 2,3,5-triphenyltetrazolium chloride (TTC) staining and Neurological Severity Scores (NSS) respectively. Expression of HDAC3, AIM2 inflammasome were detected by western blotting, PCR. Immunofluorescence was used to detect M1/M2 polarization. Luciferase activity of absent in melanoma 2 (AIM2) reporter promoter constructs was measured by fluorospectrophotometer. AIM2 knockdown and over-expression leti-virus were constructed to decrease or increase AIM2 expression. HDAC3 inhibitor RGFP966 was used to inhibit acetylation activity of HDAC3. Results: HDAC3 is widely distributed in cerebral cortex, lateral ventricular , hippocampus, cerebellar cortex ; HDAC3 and AIM2 expression were enhanced in LPS stimulated-microglia and MCAO model. A marked stimulatory effect of RGFP966 on H3K9Ac was observed in nuclear extracts form BV2 cells at the dosage of 15 uM. Treatment of RGFP966 increased both IL-4-stimulated expression of Ym-1 and CD206 at 4 h, 10 h, 24 h, 48 h. AIM2, NLRP-1 and NLRP3 significantly increased in MCAO+Vehicle group compared to sham group, but decreased in MCAO+RGFP966 group. RGFP966 inhibited the elevation of circulatory IL-18 and IL-1β induced by stroke. RGFP966 decreased infracted size and alleviated neurological deficit. Conclusions: HDAC3i alleviated ischemic stroke injury through modulating AIM2 inflammasome and microglia polarization. Selective HDAC3 inhibitor-RGFP966 could be a potential medication for combating ischemic brain injury.

scholarly journals Optogenetic Inhibition of Striatal Neuronal Activity Improves the Survival of Transplanted Neural Stem Cells and Neurological Outcomes after Ischemic Stroke in Mice

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yifan Lu ◽  
Lu Jiang ◽  
Wanlu Li ◽  
Meijie Qu ◽  
Yaying Song ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Neuronal Activity ◽  
Brain Ischemia ◽  
Fluorescent Protein ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Control Group ◽  
Striatal Neurons ◽  
And Migration

Neural stem cell (NSC) transplantation is a promising treatment to improve the recovery after brain ischemia. However, how the survival, proliferation, migration, and differentiation of implanted NSC are influenced by endogenous neuronal activity remains unclear. In this work, we used optogenetic techniques to control the activity of striatal neurons and investigated how their activity affected the survival and migration of transplanted NSCs and overall neurological outcome after ischemic stroke. NSCs cultured from transgenic mice expressing fluorescent protein were transplanted into the peri-infarct region of the striatum after transient middle cerebral artery occlusion (tMCAO) surgery. The striatal neurons were excited or inhibited for 15 minutes daily via implanted optical fiber after tMCAO. The results revealed that mice which received NSC transplantation and optogenetic inhibition had smaller brain infarct volume and increased NSC migration compared to the NSC alone or PBS group (p<0.05). In contrast, mice which received NSC transplantation and optogenetic excitation showed no difference in infarct volume and neurological behavior improvement compared to the PBS control group. In vitro experiments further revealed that the conditioned media from excited GABAergic neurons reduced NSC viability through paracrine mechanisms.Conclusion. Optogenetic inhibition of striatal neuronal activity further improved neurological recovery after NSC transplantation at the subacute phase after brain ischemia.

scholarly journals Restoration of Polyamine Metabolic Patterns inIn VivoandIn VitroModel of Ischemic Stroke following Human Mesenchymal Stem Cell Treatment

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Tae Hwan Shin ◽  
Geetika Phukan ◽  
Jeom Soon Shim ◽  
Duc-Toan Nguyen ◽  
Yongman Kim ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cell Model ◽  
Glucose Deprivation ◽  
Human Mesenchymal Stem Cell ◽  
Artery Occlusion ◽  
Control Group ◽  
Stem Cell Treatment ◽  
Cerebral Artery Occlusion

We investigated changes in PA levels by the treatment of human bone-marrow-derived mesenchymal stem cells (hBM-MSCs) in ischemic stroke in rat brain model and in cultured neuronal SH-SY5Y cells exposed to oxygen-glucose deprivation (OGD). In ischemic rat model, transient middle cerebral artery occlusion (MCAo) was performed for 2 h, followed by intravenous transplantation of hBM-MSCs or phosphate-buffered saline (PBS) the day following MCAo. Metabolic profiling analysis of PAs was examined in brains from three groups: control rats, PBS-treated MCAo rats (MCAo), and hBM-MSCs-treated MCAo rats (MCAo + hBM-MSCs). In ischemic cell model, SH-SY5Y cells were exposed to OGD for 24 h, treated with hBM-MSCs (OGD + hBM-MSCs) prior to continued aerobic incubation, and then samples were collected after coculture for 72 h. In thein vivoMCAo ischemic model, levels of some PAs in brain samples of the MCAo and MCAo + hBM-MSCs groups were significantly different from those of the control group. In particular, putrescine, cadaverine, and spermidine in brain tissues of the MCAo + hBM-MSCs group were significantly reduced in comparison to those in the MCAo group. In thein vitroOGD system,N1-acetylspermidine, spermidine,N1-acetylspermine, and spermine in cells of the OGD + hBM-MSCs group were significantly reduced compared to those of OGD group.

scholarly journals Sphingosine 1-phosphate, a Novel TREM2 Ligand, Promotes Phagocytosis and Reduce Ischemic Injury

2020 ◽  
Author(s):  
Xiu-Lan Sun ◽  
Teng-Fei Xue ◽  
Juan Ji ◽  
Ruo-Bing Guo ◽  
Yu-Qin Sun ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Infarct Volume ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Endogenous Ligand ◽  
Microglial Phagocytosis ◽  
Neurological Score ◽  
Cellular Debris ◽  
Sphingosine 1 Phosphate ◽  
Cerebral Artery Occlusion

Abstract Background: Activation of TREM2 protects against brain injury in ischemic stroke via immunoregulation. However, the endogenous ligand of TREM2 remains unknown. Here, we tested the hypothesis that S1P, an immunoregulator, functions as TREM2 ligand to promote microglial phagocytosis.Methods: SD rats, C57BL/6J mice and TREM2-/- mice were subjected to transient middle cerebral artery occlusion, and primary microglia were subjected to oxygen-glucose deprivation. Phagocytosis was investigated via immunofluorescence and two-photon microscope. LC-MS/MS, microscale thermophoresis and surface plasmon resonance were used to confirm the TREM2-S1P interaction.Results: FTY720, an analog of S1P, promoted microglial phagocytosis in ischemic stroke independent of S1PRs expressed on microglia. S1P was confirmed to be a novel endogenous ligand for TREM2 and promote cellular debris clearance. The enhanced cellular debris clearance ameliorated neurological score and infarct volume, relying on TREM2. Moreover, FTY720 was demonstrated to promote hemoglobin clearance in intracerebral hemorrhage and ameliorate hemorrhagic injury.Conlusions: The present work reveals for the first time that S1P acts as a novel endogenous ligand of TREM2 to effectively promote microglial phagocytosis, and provides a new lead compound for developing TREM2 modulator.

scholarly journals Dectin-1/Syk signaling triggers neuroinflammation after ischemic stroke in mice

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Xin-Chun Ye ◽  
Qi Hao ◽  
Wei-Jing Ma ◽  
Qiu-Chen Zhao ◽  
Wei-Wei Wang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Infarct Volume ◽  
Inos Expression ◽  
Microglial Cells ◽  
Brain Infarct ◽  
Tnf Α ◽  
Bv2 Microglial Cells ◽  
The Brain

Abstract Background Dendritic cell-associated C-type lectin-1 (Dectin-1) receptor has been reported to be involved in neuroinflammation in Alzheimer’s disease and traumatic brain injury. The present study was designed to investigate the role of Dectin-1 and its downstream target spleen tyrosine kinase (Syk) in early brain injury after ischemic stroke using a focal cortex ischemic stroke model. Methods Adult male C57BL/6 J mice were subjected to a cerebral focal ischemia model of ischemic stroke. The neurological score, adhesive removal test, and foot-fault test were evaluated on days 1, 3, 5, and 7 after ischemic stroke. Dectin-1, Syk, phosphorylated (p)-Syk, tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) expression was analyzed via western blotting in ischemic brain tissue after ischemic stroke and in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro. The brain infarct volume and Iba1-positive cells were evaluated using Nissl’s and immunofluorescence staining, respectively. The Dectin-1 antagonist laminarin (LAM) and a selective inhibitor of Syk phosphorylation (piceatannol; PIC) were used for the intervention. Results Dectin-1, Syk, and p-Syk expression was significantly enhanced on days 3, 5, and 7 and peaked on day 3 after ischemic stroke. The Dectin-1 antagonist LAM or Syk inhibitor PIC decreased the number of Iba1-positive cells and TNF-α and iNOS expression, decreased the brain infarct volume, and improved neurological functions on day 3 after ischemic stroke. In addition, the in vitro data revealed that Dectin-1, Syk, and p-Syk expression was increased following the 3-h OGD and 0, 3, and 6 h of reperfusion in BV2 microglial cells. LAM and PIC also decreased TNF-α and iNOS expression 3 h after OGD/R induction. Conclusion Dectin-1/Syk signaling plays a crucial role in inflammatory activation after ischemic stroke, and further investigation of Dectin-1/Syk signaling in stroke is warranted.

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