scholarly journals Cerebral Ischemia Causes Dysregulation of Synaptic Adhesion in Mouse Synaptosomes

2007 ◽  
Vol 28 (1) ◽  
pp. 99-110 ◽  
Author(s):  
Willard J Costain ◽  
Ingrid Rasquinha ◽  
Jagdeep K Sandhu ◽  
Peter Rippstein ◽  
Bogdan Zurakowski ◽  
...  

Synaptic pathology is observed during hypoxic events in the central nervous system in the form of altered dendrite structure and conductance changes. These alterations are rapidly reversible, on the return of normoxia, but are thought to initiate subsequent neuronal cell death. To characterize the effects of hypoxia on regulators of synaptic stability, we examined the temporal expression of cell adhesion molecules (CAMs) in synaptosomes after transient middle cerebral artery occlusion (MCAO) in mice. We focused on events preceding the onset of ischemic neuronal cell death (< 48 h). Synaptosome preparations were enriched in synaptically localized proteins and were free of endoplasmic reticulum and nuclear contamination. Electron microscopy showed that the synaptosome preparation was enriched in spheres (≈650 nm in diameter) containing secretory vesicles and postsynaptic densities. Forebrain mRNA levels of synaptically located CAMs was unaffected at 3 h after MCAO. This is contrasted by the observation of consistent downregulation of synaptic CAMs at 20 h after MCAO. Examination of synaptosomal CAM protein content indicated that certain adhesion molecules were decreased as early as 3 h after MCAO. For comparison, synaptosomal Agrn protein levels were unaffected by cerebral ischemia. Furthermore, a marked increase in the levels of p-Ctnnb1 in ischemic synaptosomes was observed. p-Ctnnb1 was detected in hippocampal fiber tracts and in cornu ammonis 1 neuronal nuclei. These results indicate that ischemia induces a dysregulation of a subset of synaptic proteins that are important regulators of synaptic plasticity before the onset of ischemic neuronal cell death.

2019 ◽  
Vol 35 (1) ◽  
Author(s):  
Dong-Ju Park ◽  
Ju-Bin Kang ◽  
Fawad-Ali Shah ◽  
Phil-Ok Koh

Abstract Cerebral ischemia is a major cause of neurodegenerative disease. It induces neuronal vulnerability and susceptibility, and leads to neuronal cell death. Resveratrol is a polyphenolic compound that acts as an anti-oxidant. It exerts a neuroprotective effect against focal cerebral ischemic injury. Akt signaling pathway is accepted as a representative cell survival pathway, including proliferation, growth, and glycogen synthesis. This study investigated whether resveratrol regulates Akt/glycogen synthase kinase-3β (GSK-3β) pathway in a middle cerebral artery occlusion (MCAO)-induced ischemic brain injury. Adult male rats were intraperitoneally injected with vehicle or resveratrol (30 mg/kg) and cerebral cortices were isolated 24 h after MCAO. Neurological behavior test, corner test, brain edema measurment, and 2,3,5-triphenyltetrazolium chloride staining were performed to elucidate the neuroprotective effects of resveratrol. Phospho-Akt and phospho-GSK-3β expression levels were measured using Western blot analysis. MCAO injury led to severe neurobehavioral deficit, infraction, and histopathological changes in cerebral cortex. However, resveratrol treatment alleviated these changes caused by MCAO injury. Moreover, MCAO injury induced decreases in phospho-Akt and phospho-GSK-3β protein levels, whereas resveratrol attenuated these decreases. Phosphorylations of Akt and GSK-3β act as a critical role for the suppression of apoptotic cell death. Thus, our finding suggests that resveratrol attenuates neuronal cell death in MCAO-induced cerebral ischemia and Akt/GSK-3β signaling pathway contributes to the neuroprotective effect of resveratrol.


2021 ◽  
Author(s):  
Jeong-Min Hong ◽  
Ji-Hong Moon ◽  
Jae-Won Seol ◽  
Sang-Youel Park

Abstract Background: Prion diseases are a group of prevalent and rapidly progressive neurodegenerative disorders that lead to chronic inflammation and neuronal cell death. Calcineurin and autophagy mediate prion-induced neurodegeneration, suggesting that inhibition of calcineurin and autophagy could be a target for therapy. Melatonin has been reported to exert neuroprotective effects against calcium-dependent neuronal cell death.Methods: Real-time quantitative PCR was used to detect mRNA levels of proinflammatory cytokines. Western blot was used to analysis p-nfkb, p-bcl10, calcineurin, prpc and autophagy flux pathway. Immunocytochemistry was used to analysis p-nfkb and calcineurin. Ca2+ levels were measured by fluo-4 using confocal microscope. Calcineurin activity was used to detect with calcineurin cellular activity assay kit. Transmission electron microscopy (TEM) was used to detect autophagy flux.Results: In the present study, we investigated whether melatonin attenuates prion peptide-mediated neuroinflammation and reduces calcineurin. We found that melatonin treatment inhibits prion protein-induced apoptosis. Melatonin inhibited calcium up-regulation and protected the cells against prion peptide‑induced neuron cell death by calcineurin inactivation. Furthermore, melatonin increased p62 protein levels and decrease LC3-II protein levels indicating autophagic flux inhibition and melatonin inhibited prion protein-induced neurotoxicity through autophagy flux inhibition.Conclusions: Taken together, our results illuminate that melatonin attenuated prion protein-induced neurinflammation through calcineurin inactivation and autophagic flux reduction, and also suggest that melatonin may provide effective strategy for therapy against neurodegenerative diseases, including prion diseases.


2021 ◽  
Vol 12 (1) ◽  
pp. 210-217
Author(s):  
Yibiao Wang ◽  
Min Xu

Abstract Background This study aimed to explore the role of miR-380-5p in cerebral ischemia/reperfusion (CIR) injury-induced neuronal cell death and the potential signaling pathway involved. Methodology Human neuroblastoma cell line SH-SY5Y cells were used in this study. Oxygen and glucose deprivation/reperfusion (OGD/R) model was used to mimic ischemia/reperfusion injury. CCK-8 assay and flow cytometry were used to examine cell survival. Quantitative real time PCR (RT-qPCR) assay and Western blotting were used to measure the change of RNA and protein expression, respectively. TargetScan and Luciferase assay was used to confirm the target of miR-380-5p. Malondialdehyde (MDA) superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) were measured using commercial kits. Results miR-380-5p was downregulated in SH-SY5Y cells after OGD/R. Cell viability was increased by miR-380-5p, while cell apoptosis was reduced by miR-380-5p mimics. MDA was reduced by miR-380-5p mimics, while SOD and GSHPx were increased by miR-380-5p. Results of TargetScan and luciferase assay have showed that BACH1 is the direct target of miR-380-5p. Expression of NRF2 was upregulated after OGD/R, but was not affected by miR-380-5p. mRNA expression of HO-1 and NQO1 and ARE activity were increased by miR-380-5p. Overexpression of BACH1 reversed the antioxidant and neuroprotective effects of miR-380-5p. Conclusion miR-380-5p inhibited cell death induced by CIR injury through target BACH1 which also facilitated the activation of NRF2, indicating the antioxidant and neuroprotective effects of miR-380-5p.


2004 ◽  
Vol 24 (9) ◽  
pp. 3794-3803 ◽  
Author(s):  
Cassandra L. Schlamp ◽  
Andrew T. Thliveris ◽  
Yan Li ◽  
Louis P. Kohl ◽  
Claudia Knop ◽  
...  

ABSTRACT ROSA3 mice were developed by retroviral insertion of the βGeo gene trap vector. Adult ROSA3 mice exhibit widespread expression of the trap gene in epithelial cells found in most organs. In the central nervous system the highest expression of βGeo is found in CA1 pyramidal cells of the hippocampus, Purkinje cells of the cerebellum, and ganglion cells of the retina. Characterization of the genomic insertion site for βGeo in ROSA3 mice shows that the trap vector is located in the first intron of Fem1c, a gene homologous to the sex-determining gene fem-1 of Caenorhabditis elegans. Transcription of the Rosa3 allele (R3) yields a spliced message that includes the first exon of Fem1c and the βGeo coding region. Although normal processing of the Fem1c transcript is disrupted in homozygous Rosa3 (Fem1cR3/R3 ) mice, some tissues show low levels of a partially processed transcript containing exons 2 and 3. Since the entire coding region of Fem1c is located in these two exons, Fem1cR3/R3 mice may still be able to express a putative FEM1C protein. To this extent, Fem1cR3/R3 mice show no adverse effects in their sexual development or fertility or in the attenuation of neuronal cell death, another function that has been attributed to both fem-1 and a second mouse homolog, Fem1b. Examination of βGeo expression in ganglion cells after exposure to damaging stimuli indicates that protein levels are rapidly depleted prior to cell death, making the βGeo reporter gene a potentially useful marker to study early molecular events in damaged neurons.


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