Resistance of isolated mammalian spinal cord white matter to oxygen-glucose deprivation

2002 ◽  
Vol 283 (3) ◽  
pp. C980-C989 ◽  
Author(s):  
Melissa A. Peasley ◽  
Riyi Shi
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Large Diameter ◽  
Membrane Damage ◽  
Glucose Deprivation ◽  
Compound Action Potential ◽  
Oxygen Glucose Deprivation ◽  
Axonal Membrane

We found that isolated guinea pig spinal cord white matter is resistant to acute oxygen-glucose deprivation. Sixty minutes of oxygen-glucose deprivation resulted in a 60% reduction of compound action potential (CAP) conductance, and there was a near complete recovery after 60 min reperfusion. Corresponding horseradish peroxidase-exclusion assay showed little axonal membrane damage. To further deprive the axons of metabolic substrate, we added 2 mM sodium cyanide or 2 mM sodium azide, both mitochondrial suppressors, to the ischemic medium, which completely abolished CAP and resulted in a 15 to ∼30% recovery postreperfusion. Both compounds preferentially reduced the conductance of large diameter axons. We suggest the residual ATP in our ischemic model can protect anatomic integrity and physiological functioning of spinal axons following ischemic insult. This further suggests that oxygen-glucose deprivation alone cannot be solely responsible for short-term functional and anatomic damage. The damaging effects of ischemia in vivo may be mediated by factors originating from the gray matter of the cord or other systemic factors; both were largely eliminated in our in vitro white matter preparation.

Effect of Ischemia In vivo and Oxygen-Glucose Deprivation In vitro on NOS Pools in the Spinal Cord: Comparative Study

2006 ◽  
Vol 26 (7-8) ◽  
pp. 1279-1292 ◽  
Author(s):  
Mária Kolesárová ◽  
Jaroslav Pavel ◽  
Nadežda Lukáčová ◽  
Dalibor Kolesár ◽  
Jozef Maršala
Keyword(s):  
Spinal Cord ◽  
Comparative Study ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation

Critical roles of decompression in functional recovery of ex vivo spinal cord white matter

2009 ◽  
Vol 10 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Hui Ouyang ◽  
Beth Galle ◽  
Jianming Li ◽  
Eric Nauman ◽  
Riyi Shi
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Ex Vivo ◽  
Membrane Damage ◽  
Compound Action Potential ◽  
Axonal Membrane ◽  
Cord Injury ◽  
Decompression Procedure ◽  
Spinal Cord Decompression ◽  
Type Of Injury

Object The correlations between functional deficits, the magnitude of compression, and the role of sustained compression during traumatic spinal cord injury remain largely unknown. Thus, the functional outcome of this type of injury with or without surgical intervention is rather unpredictable. To elucidate how severity and duration of compression affect cord function, the authors have developed a method to study electrophysiological characteristics and axonal membrane damage in white matter from guinea pig spinal cord. Methods Ventral white matter strips isolated from adult guinea pigs were compressed by a compression rod at a level of either 60 or 80% and held briefly, for 30 minutes, or for 60 minutes. In half the experimental groups, a decompression phase consisting of probe withdrawal and 30 minutes of recovery was also applied. For all cord samples, functional response was continuously monitored through compound action potential (CAP) recording. In addition, axonal membrane damage was assessed by a horseradish peroxidase (HRP) exclusion assay. Results After 30 minutes of sustained compression at levels of 60 or 80%, a spinal cord decompression procedure caused a significant CAP recovery, with specimens reaching 97.5 ± 6.84% (p < 0.05) and 56.2 ± 6.14% (p < 0.05) of preinjury amplitude, respectively. After 60 minutes of compression, the amount of CAP recovery following the decompression stage was only 65.5 ± 9.33% for 60% compression (p < 0.05) and 29.8 ± 6.31% for 80% compression (p < 0.05). Unlike the CAP response, HRP uptake did not increase during sustained compression, and the data showed that HRP staining was primarily time dependent. Conclusions The degree of axonal membrane damage is not exacerbated during sustained compression. However, the electrical conductivity of the cord white matter weakens throughout the duration of compression. Therefore, decompression is a viable procedure for preservation of neurological function following compressive injury.

scholarly journals Upregulation of miR-216a exerts neuroprotective effects against ischemic injury through negatively regulating JAK2/STAT3-involved apoptosis and inflammatory pathways

2019 ◽  
Vol 130 (3) ◽  
pp. 977-988 ◽  
Author(s):  
Yu Shuang Tian ◽  
Di Zhong ◽  
Qing Qing Liu ◽  
Xiu Li Zhao ◽  
Hong Xue Sun ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Inflammatory Mediators ◽  
Neurological Deficit ◽  
Ischemic Injury ◽  
Glucose Deprivation ◽  
Luciferase Assay ◽  
Oxygen Glucose Deprivation ◽  
Tnf Α

OBJECTIVEIschemic stroke remains a significant cause of death and disability in industrialized nations. Janus tyrosine kinase (JAK) and signal transducer and activator of transcription (STAT) of the JAK2/STAT3 pathway play important roles in the downstream signal pathway regulation of ischemic stroke–related inflammatory neuronal damage. Recently, microRNAs (miRNAs) have emerged as major regulators in cerebral ischemic injury; therefore, the authors aimed to investigate the underlying molecular mechanism between miRNAs and ischemic stroke, which may provide potential therapeutic targets for ischemic stroke.METHODSThe JAK2- and JAK3-related miRNA (miR-135, miR-216a, and miR-433) expression levels were detected by real-time quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and Western blot analysis in both oxygen-glucose deprivation (OGD)–treated primary cultured neuronal cells and mouse brain with middle cerebral artery occlusion (MCAO)–induced ischemic stroke. The miR-135, miR-216a, and miR-433 were determined by bioinformatics analysis that may target JAK2, and miR-216a was further confirmed by 3′ untranslated region (3′UTR) dual-luciferase assay. The study further detected cell apoptosis, the level of lactate dehydrogenase, and inflammatory mediators (inducible nitric oxide synthase [iNOS], matrix metalloproteinase–9 [MMP-9], tumor necrosis factor–α [TNF-α], and interleukin-1β [IL-1β]) after cells were transfected with miR-NC (miRNA negative control) or miR-216a mimics and subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) damage with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, annexin V–FITC/PI, Western blots, and enzyme-linked immunosorbent assay detection. Furthermore, neurological deficit detection and neurological behavior grading were performed to determine the infarction area and neurological deficits.RESULTSJAK2 showed its highest level while miR-216a showed its lowest level at day 1 after ischemic reperfusion. However, miR-135 and miR-433 had no obvious change during the process. The luciferase assay data further confirmed that miR-216a can directly target the 3′UTR of JAK2, and overexpression of miR-216a repressed JAK2 protein levels in OGD/R-treated neuronal cells as well as in the MCAO model ischemic region. In addition, overexpression of miR-216a mitigated cell apoptosis both in vitro and in vivo, which was consistent with the effect of knockdown of JAK2. Furthermore, the study found that miR-216a obviously inhibited the inflammatory mediators after OGD/R, including inflammatory enzymes (iNOS and MMP-9) and cytokines (TNF-α and IL-1β). Upregulating miR-216a levels reduced ischemic infarction and improved neurological deficit.CONCLUSIONSThese findings suggest that upregulation of miR-216a, which targets JAK2, could induce neuroprotection against ischemic injury in vitro and in vivo, which provides a potential therapeutic target for ischemic stroke.

scholarly journals Mechanism of antrocytic connexin-43 autophagy degradation in oxygen-glucose deprivation and its effect on neuroinflammation

2019 ◽  
Author(s):  
Xinyu Wang ◽  
Liangshu Feng ◽  
Meiying Xin ◽  
Yulei Hao ◽  
Xu Wang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Connexin 43 ◽  
Cell Communication ◽  
Glucose Deprivation ◽  
In Vivo Model ◽  
Oxygen Glucose Deprivation ◽  
Cx43 Protein ◽  
Protein Levels

Abstract Background : Connexin 43 (Cx43) are the most widely distributed gap junction proteins in the nervous system. Cx43 enables cell-to-cell communication and plays an important role in ion transport, substrate exchange and delivery of information , which have been implicated in cerebral ischemia injury. Our previous work revealed the relationships between Cx43 and glia-mediated neuroinflammation through the release of ATP in oxygen-glucose deprivation (OGD), which means degradation of Cx43 may improve neuroinflammatory damage during OGD injury . However, the roles of Cx43 degradation and neuroinflammation caused by OGD remain unclear. Methods: We used primary cultured astrocytes treated with OGD as an in vitro model of cerebral ischemia injury and we used middle cerebral artery occlusion (MCAO) model as an in vivo model of cerebral ischemia. HeLa cells were used in overexpression experiments. Cx43 protein levels were determined by western blotting. The interaction between Cx43 and related autophagy receptors was determined by co-immunoprecipitation and immunofluorescence. The gene knockdown (KD) of ATG5, OPTN, NDP52, PINK1 and Cx43 was applied by siRNA transfection. Related cytokines were detected by cytometric bead assay. Results: We found that Cx43 protein levels increased after ischemia in gene KD of ATG5, OPTN, NDP52 and PINK1 primary astrocytes. The interaction of Cx43 with OPTN, NDP52 and PINK1 was increased after cerebral ischemia injury in vitro and vivo. While the interaction was weakened after point mutation of Cx43 at Ser368, Tyr265 and Tyr247. Meanwhile, IL-10 upregulated during OGD after KD of ATG5, OPTN, NDP52 and PINK1 in astrocytes , while TNF downregulated during OGD after KD of ATG5, OPTN, NDP52 and PINK1 in astrocytes. Conclusions: Our results suggest that degradation of Cx43 is caused by selective autophagy during ischemia injury and the autophagy degradation of Cx43 plays important roles in neuroinflammation mediated by OGD injury. Treatment targeting Cx43 degradation pathway can improve neuroinflammation responses induced by OGD injury , which provide novel therapeutic strategies and crosstalk between autophagy and neuroinflammation.

scholarly journals Methylglyoxal Scavengers Attenuate Angiogenesis Dysfunction Induced by Methylglyoxal and Oxygen-Glucose Deprivation

2022 ◽  
Vol 2022 ◽  
pp. 1-18
Author(s):  
Wei Chen ◽  
Wenhui Huang ◽  
Yu Yang ◽  
Keshen Li
Keyword(s):  
Endothelial Cells ◽  
Chorioallantoic Membrane ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation ◽  
Ros Generation ◽  
Advanced Glycation ◽  
Related Factors ◽  
Cellular Apoptosis

Cerebral endothelial cells play an essential role in brain angiogenesis, and their function has been found to be impaired in diabetes. Methylglyoxal (MG) is a highly reactive dicarbonyl metabolite of glucose formed mainly during glycolysis, and its levels can be elevated in hyperglycemic conditions. MG is a potent precursor of AGEs (advanced glycation end-products). In this study, we investigated if MG can induce angiogenesis dysfunction and whether MG scavengers can ameliorate angiogenesis dysfunction induced by MG. Here, we used cultured human brain microvascular endothelial cells (HBMECs) treated with MG and oxygen-glucose deprivation (OGD) to mimic diabetic stroke in vitro. We also used the MG challenged chicken embryo chorioallantoic membrane (CAM) to study angiogenesis in vivo. Interestingly, administration of MG significantly impaired cell proliferation, cell migration, and tube formation and decreased protein expression of angiogenesis-related factors, which was rescued by three different MG scavengers, glyoxalase 1 (GLO1), aminoguanidine (AG), and N-acetyl cysteine (NAC). In cultured CAM, MG exposure significantly reduced angiogenesis and the angiogenesis-related dysfunction could be attenuated by pretreatment with AG or NAC. Treatment of cultured HBMECs with MG plus OGD increased cellular apoptosis significantly, which could be prevented by exposure to GLO1, AG, or NAC. We also noted that administration of MG increased cellular oxidative stress as measured by reactive oxygen species (ROS) generation, enhanced AGE accumulation, and receptor for advanced glycation end-product (RAGE) expression in the cultured HBMECs, which were partially reversed by GLO1, AG, or NAC. Taken together, our findings demonstrated that GLO1, AG, or NAC administration can ameliorate MG-induced angiogenesis dysfunction, and this can be mainly attributed to attenuated ROS production, reduced cellular apoptosis, and increased levels of angiogenic factors. Overall, this study suggested that GLO1, AG, or NAC may be promising candidate compounds for the treatment of angiogenesis dysfunction caused by hyperglycemia in diabetic ischemic stroke.

scholarly journals EphrinB2-EphB2 signaling for dendrite protection after neuronal ischemia in vivo and oxygen-glucose deprivation in vitro

2020 ◽  
pp. 0271678X2097311
Author(s):  
Zhanyang Yu ◽  
Wenlu Li ◽  
Jing Lan ◽  
Kazuhide Hayakawa ◽  
Xunming Ji ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Mouse Model ◽  
Therapeutic Potential ◽  
Focal Cerebral Ischemia ◽  
Ischemic Injury ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation ◽  
Neuron Soma

In order to rescue neuronal function, neuroprotection should be required not only for the neuron soma but also the dendrites. Here, we propose the hypothesis that ephrin-B2-EphB2 signaling may be involved in dendritic degeneration after ischemic injury. A mouse model of focal cerebral ischemia with middle cerebral artery occlusion (MCAO) method was used for EphB2 signaling test in vivo. Primary cortical neuron culture and oxygen-glucose deprivation were used to assess EphB2 signaling in vitro. siRNA and soluble ephrin-B2 ectodomain were used to block ephrin-B2-Ephb2 signaling. In the mouse model of focal cerebral ischemia and in neurons subjected to oxygen-glucose deprivation, clustering of ephrin-B2 with its receptor EphB2 was detected. Phosphorylation of EphB2 suggested activation of this signaling pathway. RNA silencing of EphB2 prevented neuronal death and preserved dendritic length. To assess therapeutic potential, we compared the soluble EphB2 ectodomain with the NMDA antagonist MK801 in neurons after oxygen-glucose deprivation. Both agents equally reduced lactate dehydrogenase release as a general marker of neurotoxicity. However, only soluble EphB2 ectodomain protected the dendrites. These findings provide a proof of concept that ephrin-B2-EphB2 signaling may represent a novel therapeutic target to protect both the neuron soma as well as dendrites against ischemic injury.

scholarly journals A novel therapeutic approach using peripheral blood mononuclear cells preconditioned by oxygen-glucose deprivation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Masahiro Hatakeyama ◽  
Masato Kanazawa ◽  
Itaru Ninomiya ◽  
Kaoru Omae ◽  
Yasuko Kimura ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Therapeutic Strategy ◽  
Mononuclear Cells ◽  
Focal Cerebral Ischemia ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation ◽  
Peripheral Blood Mononuclear ◽  
Novel Therapeutic

AbstractCell therapies that invoke pleiotropic mechanisms may facilitate functional recovery in patients with stroke. Based on previous experiments using microglia preconditioned by oxygen-glucose deprivation, we hypothesized that the administration of peripheral blood mononuclear cells (PBMCs) preconditioned by oxygen-glucose deprivation (OGD-PBMCs) to be a therapeutic strategy for ischemic stroke. Here, OGD-PBMCs were identified to secrete remodelling factors, including the vascular endothelial growth factor and transforming growth factor-β in vitro, while intra-arterial administration of OGD-PBMCs at 7 days after focal cerebral ischemia prompted expression of such factors in the brain parenchyma at 28 days following focal cerebral ischemia in vivo. Furthermore, administration of OGD-PBMCs induced an increasing number of stage-specific embryonic antigen-3-positive cells both in vitro and in vivo. Finally, it was found to prompt angiogenesis and axonal outgrowth, and functional recovery after cerebral ischemia. In conclusion, the administration of OGD-PBMCs might be a novel therapeutic strategy against ischemic stroke.

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