scholarly journals Silencing of Long Noncoding RNA Nespas Aggravates Microglial Cell Death and Neuroinflammation in Ischemic Stroke

Stroke ◽  
2019 ◽  
Vol 50 (7) ◽  
pp. 1850-1858 ◽  
Author(s):  
Yiming Deng ◽  
Duanduan Chen ◽  
Luyao Wang ◽  
Feng Gao ◽  
Bo Jin ◽  
...  
Keyword(s):  
Cell Death ◽  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Noncoding Rnas ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Oxygen Glucose Deprivation ◽  
Cerebral Artery Occlusion

Background and Purpose— Ischemic stroke is one of the leading causes of morbidity and mortality worldwide and a major cause of long-term disability. Recently, long noncoding RNAs have been revealed, which are tightly associated with several human diseases. However, the functions of long noncoding RNAs in ischemic stroke still remain largely unknown. In the current study, for the first time, we investigated the role of long noncoding RNA Nespas in ischemic stroke. Methods— We used in vivo models of middle cerebral artery occlusion and in vitro models of oxygen-glucose deprivation to illustrate the effect of long noncoding RNA Nespas on ischemic stroke. Results— We found expression of Nespas was significantly increased in ischemic cerebral tissues and oxygen-glucose deprivation–treated BV2 cells in a time-dependent manner. Silencing of Nespas aggravated middle cerebral artery occlusion operation–induced IR injury and cell death. In addition, proinflammatory cytokine production and NF-κB (nuclear factor-κB) signaling activation were inhibited by Nespas overexpression. TAK1 (transforming growth factor-β–activated kinase 1) was found to directly interact with Nespas, and TAK1 activation was significantly suppressed by Nespas. At last, we found Nespas-inhibited TRIM8 (tripartite motif 8)-induced K63-linked polyubiquitination of TAK1. Conclusions— We showed that Nespas played anti-inflammatory and antiapoptotic roles in cultured microglial cells after oxygen-glucose deprivation stimulation and in mice after ischemic stroke by inhibiting TRIM8-related K63-linked polyubiquitination of TAK1.

scholarly journals Eye Opener in Stroke

Stroke ◽  
2019 ◽  
Vol 50 (8) ◽  
pp. 2197-2206 ◽  
Author(s):  
Hung Nguyen ◽  
Jea Young Lee ◽  
Paul R. Sanberg ◽  
Eleonora Napoli ◽  
Cesar V. Borlongan
Keyword(s):  
Cell Death ◽  
Mitochondrial Dysfunction ◽  
Glucose Deprivation ◽  
Retinal Ischemia ◽  
Artery Occlusion ◽  
Oxygen Glucose Deprivation ◽  
Retinal Pigmented Epithelium ◽  
Pigmented Epithelium ◽  
Cerebral Artery Occlusion ◽  
Epithelium Cells

Background and Purpose— Retinal ischemia is a major cause of visual impairment in stroke patients, but our incomplete understanding of its pathology may contribute to a lack of effective treatment. Here, we investigated the role of mitochondrial dysfunction in retinal ischemia and probed the potential of mesenchymal stem cells (MSCs) in mitochondrial repair under such pathological condition. Methods— In vivo, rats were subjected to middle cerebral artery occlusion then randomly treated with intravenous MSCs or vehicle. Laser Doppler was used to evaluate the blood flow in the brain and the eye, while immunohistochemical staining assessed cellular degeneration at days 3 and 14 poststroke. In vitro, retinal pigmented epithelium cells were exposed to either oxygen-glucose deprivation or oxygen-glucose deprivation and coculture with MSCs, and subsequently, cell death and mitochondrial function were examined immunocytochemically and with Seahorse analyzer, respectively. Results— Middle cerebral artery occlusion significantly reduced blood flow in the brain and the eye accompanied by mitochondrial dysfunction and ganglion cell death at days 3 and 14 poststroke. Intravenous MSCs elicited mitochondrial repair and improved ganglion cell survival at day 14 poststroke. Oxygen-glucose deprivation similarly induced mitochondrial dysfunction and cell death in retinal pigmented epithelium cells; coculture with MSCs restored mitochondrial respiration, mitochondrial network morphology, and mitochondrial dynamics, which likely attenuated oxygen-glucose deprivation-mediated retinal pigmented epithelium cell death. Conclusions— Retinal ischemia is closely associated with mitochondrial dysfunction, which can be remedied by stem cell-mediated mitochondrial repair.

Neuroprotective Effects of Propofol in Models of Cerebral Ischemia

2006 ◽  
Vol 104 (1) ◽  
pp. 80-89 ◽  
Author(s):  
Chiara Adembri ◽  
Luna Venturi ◽  
Alessia Tani ◽  
Alberto Chiarugi ◽  
Elena Gramigni ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Mitochondrial Swelling ◽  
Oxygen Glucose Deprivation ◽  
Neuroprotective Effects ◽  
Cerebral Artery Occlusion

Background Propofol (2,6-diisopropylphenol) has been shown to attenuate neuronal injury in a number of experimental conditions, but studies in models of cerebral ischemia have yielded conflicting results. Moreover, the mechanisms involved in its neuroprotective effects are yet unclear. Methods The authors evaluated the neuroprotective effects of propofol in rat organotypic hippocampal slices exposed to oxygen-glucose deprivation, an in vitro model of cerebral ischemia. To investigate its possible mechanism of action, the authors then examined whether propofol could reduce Ca2+-induced rat brain mitochondrial swelling, an index of mitochondrial membrane permeability, as well as the mitochondrial swelling evoked by oxygen-glucose deprivation in CA1 pyramidal cells by transmission electron microscopy. Finally, they evaluated whether propofol could attenuate the infarct size and improve the neurobehavioral outcome in rats subjected to permanent middle cerebral artery occlusion in vivo. Results When present in the incubation medium during oxygen-glucose deprivation and the subsequent 24 h recovery period, propofol (10-100 microM) attenuated CA1 injury in hippocampal slices in vitro. Ca2+-induced brain mitochondrial swelling was prevented by 30-100 microM propofol, and so were the ultrastructural mitochondrial changes in CA1 pyramidal cells exposed to oxygen-glucose deprivation. Twenty-four hours after permanent middle cerebral artery occlusion, propofol (100 mg/kg, intraperitoneal) reduced the infarct size by approximately 30% when administered immediately after and up to 30 min after the occlusion. Finally, propofol administered within 30 min after middle cerebral artery occlusion was unable to affect the global neurobehavioral score but significantly preserved spontaneous activity in ischemic rats. Conclusions These results show that propofol, at clinically relevant concentrations, is neuroprotective in models of cerebral ischemia in vitro and in vivo and that it may act by preventing the increase in neuronal mitochondrial swelling.

scholarly journals Histone Methyltransferase Dot1L Contributes to RIPK1 Kinase‐Dependent Apoptosis in Cerebral Ischemia/Reperfusion

2021 ◽  
Author(s):  
Jinghuan Wang ◽  
Wen Zhong ◽  
Haibi Su ◽  
Jie Xu ◽  
Di Yang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Promoter Region ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Oxygen Glucose Deprivation ◽  
Cerebral Artery Occlusion ◽  
Neuron Apoptosis

Background Neuron apoptosis is a pivotal process for brain damage in cerebral ischemia. Dot1L (disruptor of telomeric silencing 1‐like) is only known histone H3K79 methyltransferase. It is not clear whether the role and mechanism of Dot1L on cerebral ischemia is related to regulate neuron apoptosis. Methods and Results We use a combination of mice middle cerebral artery occlusion stroke and neurons exposed to oxygen‐glucose deprivation followed by reoxygenation to investigate the role and mechanism of Dot1L on cerebral ischemia. We find knockdown or inhibition of Dot1L reversed ischemia‐induced neuronal apoptosis and attenuated the neurons injury treated by oxygen‐glucose deprivation followed by reoxygenation. Further, blockade of Dot1L prevents RIPK1 (receptor‐interacting protein kinase 1)‐dependent apoptosis through increased RIPK1 K63‐ubiquitylation and decreased formation of RIPK1/Caspase 8 complexes. In line with this, H3K79me3 enrichment in the promoter region of deubiquitin‐modifying enzyme A20 and deubiquitinase cylindromatosis gene promotes the increasing expression in oxygen‐glucose deprivation followed by reoxygenation ‐induced neuronal cells, on the contrary, oxygen‐glucose deprivation followed by reoxygenation decreases H3K79me3 level in the promoter region of ubiquitin‐modifying enzyme cIAP1 (cellular inhibitors of apoptosis proteins), and both these factors ultimately cause K63‐deubiquitination of RIPK1. Importantly, knockdown or inhibition of Dot1L in vivo attenuates apoptosis in middle cerebral artery occlusion mice and reduces the extent of middle cerebral artery occlusion ‐induced brain injury. Conclusions These data support for the first time, to our knowledge, that Dot1L regulating RIPK1 to the apoptotic death trigger contributes to cerebral ischemia injury. Therefore, targeting Dot1L serves as a new therapeutic strategy for ischemia stroke.

scholarly journals Neuroprotective Effect of SCM-198 through Stabilizing Endothelial Cell Function

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Qiu-Yan Zhang ◽  
Zhi-Jun Wang ◽  
Lei Miao ◽  
Ying Wang ◽  
Ling-Ling Chang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Signaling Pathway ◽  
Cell Function ◽  
Neuroprotective Effect ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Oxygen Glucose Deprivation ◽  
Endothelial Cell Function ◽  
Cerebral Artery Occlusion

Leonurine, also named SCM-198, which was extracted from Herba leonuri, displayed a protective effect on various cardiovascular and brain diseases, like ischemic stroke. Ischemic stroke which is the leading cause of morbidity and mortality, ultimately caused irreversible neuron damage. This study is aimed at exploring the possible therapeutic potential of SCM-198 in the protection against postischemic neuronal injury and possible underlying mechanisms. A transient middle cerebral artery occlusion (tMCAO) rat model was utilized to measure the protective effect of SCM-198 on neurons. TEM was used to determine neuron ultrastructural changes. The brain slices were stained with Nissl staining solution for Nissl bodies. Fluoro-Jade B (FJB) was used for staining the degenerating neurons. In the oxygen-glucose deprivation and re-oxygenation (OGD/R) model of bEnd.3 cells treated with SCM-198 (0.1, 1, 10 μM). Then, the bEnd.3 cells were cocultured with SH-SY5Y cells. Cell viability, MDA level, CAT activity, and apoptosis were examined to evaluate the cytotoxicity of these treatments. Western blot and immunofluorescent assays were used to examine the expression of protein related to the p-STAT3/NOX4/Bcl-2 signaling pathway. Coimmunoprecipitation was performed to determine the interaction between p-STAT3 and NOX4. In the transient middle cerebral artery occlusion (tMCAO) rat model, we found that treatment with SCM-198 could ameliorate neuron morphology and reduce the degenerating cell and neuron loss. In the in vitro model of bEnd.3 cell oxygen-glucose deprivation and reoxygenation (OGD/R), treatment with SCM-198 restored the activity of catalase (CAT), improved the expression of Cu-Zn superoxide dismutase (SOD1), and decreased the malondialdehyde (MDA) production. SCM-198 treatment prevented OGD/R-induced cell apoptosis as indicated by increased cell viability and decreased the number of TUNEL-positive cells, accompanied with upregulation of Bcl-2 and Bcl-xl protein and downregulation Bax protein. The results were consistent with SH-SY5Y cells which coculture with bEnd.3 cells. The forthcoming study revealed that SCM-198 activated the p-STAT3/NOX4/Bcl-2 signaling pathway. All the data indicated that SCM-198 protected against oxidative stress and neuronal damage in in vivo and in vitro injury models via the p-STAT3/NOX4/Bcl-2 signaling pathway. Our results suggested that SCM-198 could be the potential drug for neuroprotective effect through stabilizing endothelial cell function.

Energy-Sensing Pathways in Ischemia: The Counterbalance Between AMPK and mTORC

2020 ◽  
Vol 25 (45) ◽  
pp. 4763-4770
Author(s):  
Angel Cespedes ◽  
Mario Villa ◽  
Irene Benito-Cuesta ◽  
Maria J. Perez-Alvarez ◽  
Lara Ordoñez ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Cause Of Death ◽  
Artery Occlusion ◽  
Brain Pathology ◽  
Common Cause ◽  
Specific Analysis ◽  
Energy Sensing ◽  
Cerebral Artery Occlusion

: Stroke is an important cause of death and disability, and it is the second leading cause of death worldwide. In humans, middle cerebral artery occlusion (MCAO) is the most common cause of ischemic stroke. The damage occurs due to the lack of nutrients and oxygen contributed by the blood flow. : The present review aims to analyze to what extent the lack of each of the elements of the system leads to damage and which mechanisms are unaffected by this deficiency. We believe that the specific analysis of the effect of lack of each component could lead to the emergence of new therapeutic targets for this important brain pathology.

scholarly journals The Key Regulator of Necroptosis, RIP1 Kinase, Contributes to the Formation of Astrogliosis and Glial Scar in Ischemic Stroke

2021 ◽  
Author(s):  
Yong-Ming Zhu ◽  
Liang Lin ◽  
Chao Wei ◽  
Yi Guo ◽  
Yuan Qin ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Glial Scar ◽  
Scar Formation ◽  
Reactive Astrocytes ◽  
Interacting Protein ◽  
Protein Levels ◽  
Endothelial Growth Factor ◽  
Cerebral Artery Occlusion

AbstractNecroptosis initiation relies on the receptor-interacting protein 1 kinase (RIP1K). We recently reported that genetic and pharmacological inhibition of RIP1K produces protection against ischemic stroke-induced astrocytic injury. However, the role of RIP1K in ischemic stroke-induced formation of astrogliosis and glial scar remains unknown. Here, in a transient middle cerebral artery occlusion (tMCAO) rat model and an oxygen and glucose deprivation and reoxygenation (OGD/Re)-induced astrocytic injury model, we show that RIP1K was significantly elevated in the reactive astrocytes. Knockdown of RIP1K or delayed administration of RIP1K inhibitor Nec-1 down-regulated the glial scar markers, improved ischemic stroke-induced necrotic morphology and neurologic deficits, and reduced the volume of brain atrophy. Moreover, knockdown of RIP1K attenuated astrocytic cell death and proliferation and promoted neuronal axonal generation in a neuron and astrocyte co-culture system. Both vascular endothelial growth factor D (VEGF-D) and its receptor VEGFR-3 were elevated in the reactive astrocytes; simultaneously, VEGF-D was increased in the medium of astrocytes exposed to OGD/Re. Knockdown of RIP1K down-regulated VEGF-D gene and protein levels in the reactive astrocytes. Treatment with 400 ng/ml recombinant VEGF-D induced the formation of glial scar; conversely, the inhibitor of VEGFR-3 suppressed OGD/Re-induced glial scar formation. RIP3K and MLKL may be involved in glial scar formation. Taken together, these results suggest that RIP1K participates in the formation of astrogliosis and glial scar via impairment of normal astrocyte responses and enhancing the astrocytic VEGF-D/VEGFR-3 signaling pathways. Inhibition of RIP1K promotes the brain functional recovery partially via suppressing the formation of astrogliosis and glial scar. Graphical Abstract

Abstract 166: Endothelial Overexpression of LOX-1 Increases Stroke Size in vivo

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Alexander Akhmedov ◽  
Remo D Spescha ◽  
Francesco Paneni ◽  
Giovani G Camici ◽  
Thomas F Luescher
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Endothelial Dysfunction ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Oxidized Ldl ◽  
Artery Occlusion ◽  
Cerebral Artery Occlusion ◽  
The Brain

Background— Stroke is one of the most common causes of death and long term disability worldwide primarily affecting the elderly population. Lectin-like oxidized LDL receptor 1 (LOX-1) is the receptor for oxidized LDL identified in endothelial cells. Binding of OxLDL to LOX-1 induces several cellular events in endothelial cells, such as activation of transcription factor NF-kB, upregulation of MCP-1, and reduction in intracellular NO. Accumulating evidence suggests that LOX-1 is involved in endothelial dysfunction, inflammation, atherogenesis, myocardial infarction, and intimal thickening after balloon catheter injury. Interestingly, a recent study demonstrated that acetylsalicylic acid (aspirin), which could prevent ischemic stroke, inhibited Ox-LDL-mediated LOX-1 expression in human coronary endothelial cells. The expression of LOX-1 was increased at a transient ischemic core site in the rat middle cerebral artery occlusion model. These data suggest that LOX-1 expression induces atherosclerosis in the brain and is the precipitating cause of ischemic stroke. Therefore, the goal of the present study was to investigate the role of endothelial LOX-1 in stroke using experimental mouse model. Methods and Results— 12-week-old male LOX-1TG generated recently in our group and wild-type (WT) mice were applied for a transient middle cerebral artery occlusion (MCAO) model to induce ischemia/reperfusion (I/R) brain injury. LOX-1TG mice developed 24h post-MCAO significantly larger infarcts in the brain compared to WT (81.51±8.84 vs. 46.41±10.13, n=7, p < 0.05) as assessed morphologically using Triphenyltetrazolium chloride (TTC) staining. Moreover, LOX-1TG showed higher neurological deficit in RotaRod (35.57±8.92 vs. 66.14±10.63, n=7, p < 0.05) and Bederson tests (2.22±0.14 vs. 1.25±0.30, n=9-12, p < 0.05) - two experimental physiological tests for neurological function. Conclusions— Thus, our data suggest that LOX-1 plays a critical role in the ischemic stroke when expressed at unphysiological levels. Such LOX-1 -associated phenotype could be due to the endothelial dysfunction. Therefore, LOX-1 may represent novel therapeutic targets for preventing ischemic stroke.

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