Oxygen-Glucose-Deprivation/Reoxygenation-Induced Autophagic Cell Death Depends on JNK-Mediated Phosphorylation of Bcl-2

Background/Aims: The purpose of this study was to investigate the role of autophagy in oxygen-glucose-deprivation/reoxygenation (OGD/R) injury in rat neurons. Methods and results: Cortical neurons were isolated from Sprague-Dawley rats and identified by immunofluorescence. The cortical neurons were randomly assigned to one of four groups: control group (I), experimental group (OGD/R group, II), JNK inhibitor pretreatment group (III) and JNK inhibitor pretreatment + OGD/R group (IV). Neuronal cell viability significantly decreased after 6h and 12h of reoxygenation in Group IV (P < 0.05). Electron microscopy showed the presence of many autophagic vacuoles and the formation of autolysosomes in the neurons; the number of autophagic vacuoles decreased transiently at 6h, while a new autophagic flux and a large number of empty autophagic vacuoles were observed at 12h. In Group IV, a large number of autophagic vacuoles were present at 0.5h and 2h of reoxygenation, which gradually decreased with increasing reoxygenation time. No significant differences in the expression of the LC3II protein were detected between the Group II and IV prior to 6h of reoxygenation, and LC3II expression showed an overall rise-decline pattern. However, LC3II protein expression increased in Group II at 12h of reoxygenation, whereas a continuous decline was observed in Group IV. The levels of phosphorylated JNK and Bcl-2 and the expression of Beclin-1 increased gradually as the reoxygenation time going in Group II, whereas they increased at 12h of reoxygenation in Group IV (P < 0.05). In addition, progressive dissociation of the Bcl-2/Beclin-1 complex was observed in the Group II, while JNK inhibitor suppressed this dissociation. Conclusion: The regulation of the JNK/Bcl-2/Beclin-1 signaling pathway may be one of the mechanisms underlying the OGD/R-induced autophagic cell death of neurons.

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Faculty Opinions recommendation of Regulation of an ATG7-beclin 1 program of autophagic cell death by caspase-8.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1018916.239562 ◽

2004 ◽

Author(s):

Vojo Deretic

Keyword(s):

Cell Death ◽

Autophagic Cell Death ◽

Beclin 1 ◽

Caspase 8

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Faculty Opinions recommendation of Regulation of an ATG7-beclin 1 program of autophagic cell death by caspase-8.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1018916.214487 ◽

2004 ◽

Author(s):

Sharad Kumar

Keyword(s):

Cell Death ◽

Autophagic Cell Death ◽

Beclin 1 ◽

Caspase 8

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Faculty Opinions recommendation of Oncogenic Ras-induced expression of Noxa and Beclin-1 promotes autophagic cell death and limits clonogenic survival.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.9113962.10228054 ◽

2011 ◽

Author(s):

Andreas Villunger

Keyword(s):

Cell Death ◽

Clonogenic Survival ◽

Autophagic Cell Death ◽

Beclin 1 ◽

Induced Expression ◽

Oncogenic Ras

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Different Treatment Protocols of Retained Fetal Membranes and its Effect on Serum Profile, Uterine Involution and Postpartum Fertility in Cows

THE INDIAN JOURNAL OF VETERINARY SCIENCES AND BIOTECHNOLOGY ◽

10.21887/ijvsbt.14.4.4 ◽

2019 ◽

Vol 14 (04) ◽

Author(s):

A. I. Shah ◽

D. M. Patel ◽

N. P. Sarvaiya ◽

S. P. Madhira

Keyword(s):

Group Iv ◽

Fetal Membranes ◽

Serum Progesterone ◽

Group V ◽

Manual Removal ◽

Uterine Involution ◽

Group I ◽

Medicinal Treatment ◽

Group Ii ◽

Postpartum Estrus

This study was undertaken on 36 freshly calved cows randomly divided into 6 equal groups under field conditions. Cows of group-VI that shed placenta within 8-12 hours postpartum naturally served as healthy control. The cows with retained fetal membranes (RFM, n = 18) for more than 12 hrs were managed either by manual removal of placenta without antibiotics (group-I), parenteral antibiotic (Ceftiofur 1 g i/m) for three consecutive days (group-II) or a combination of both (group-III). In group-IV and group-V, cows were administered with Inj. Oxytocin @ 50 IU i/m and Inj. Dinoprost tromethamine (PGF2α) @ 25 mg i/m, respectively, immediately after parturition and time of placental shedding was recorded. The overall prevalence of Brucellosis by RBPT was found to be 5.55 % amongst these 36 animals. The placental expulsion in groups following medicinal treatment was found to be 50 (3/6) % in Ceftiofur alone by 3 days (group-II), and 66.67 (4/6) % in Oxytocin (group-IV) and 100 (6/6) % in PGF2α inj. (group-V) groups within 12 hrs. The time of uterine involution in groups I to VI was found to be 42.00 ± 1.94, 39.50 ± 0.99, 40.67 ± 1.39, 38.33 ± 1.55, 37.50 ± 1.02 and 37.33 ± 1.76 days, respectively, while the interval for the appearance of first postpartum estrus was 54.83 ± 2.06, 51.00 ± 1.05, 52.17 ± 1.96, 50.17 ± 2.03, 48.67 ± 1.90 and 49.17 ± 1.55 days, respectively, which did not vary statistically. The mean serum progesterone profile obtained on day 0 and day 21 postpartum was statistically non-significant between groups. However, it was significantly (p less than 0.05) lower on day 0 as compared to day 21 in group-I, II and VI. The levels on day 0 coincided with the time of blood sampling after calving. The high level of serum P4 on day 0 in group-IV and V could be due to sampling immediately after calving. The serum calcium and phosphorus levels were significantly(p less than 0.05) lower on day 0 than on day 21, but not the magnesium. The group effect was however non-significant for any of three minerals. It was observed that manual removal of RFM without parenteral antibiotics, resulted in puerperal metritis, cervicitis, pyometra which ultimately resulted into delayed uterine involution, delayed first postpartum estrus and thus, reduced the postpartum reproductive efficiency. It was inferred that the PGF2α and Oxytocin injections could be used as a treatment of choice for prevention of RFMs in cattle.

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Nrf2 mediates the neuroprotective effect of isoflurane preconditioning in cortical neuron injury induced by oxygen-glucose deprivation

Human & Experimental Toxicology ◽

10.1177/0960327121989416 ◽

2021 ◽

pp. 096032712198941

Author(s):

X-S Liu ◽

X-L Bai ◽

Z-X Wang ◽

S-Y Xu ◽

Y Ma ◽

...

Keyword(s):

Oxidative Stress ◽

Cortical Neuron ◽

Cortical Neurons ◽

Glucose Deprivation ◽

Oxygen Glucose Deprivation ◽

Lactate Dehydrogenase Activity ◽

Primary Mouse ◽

Ldh Release ◽

Neuron Injury ◽

And Oxidative Stress

Objective: To investigate how nuclear factor-E2-related factor 2 (Nrf2) involved in the protective effect of isoflurane (Iso) preconditioning in oxygen glucose deprivation (OGD)-induced cortical neuron injury. Methods: Primary mouse cortical neurons were divided into Control, ML385 (an Nrf2 inhibitor), Iso, Iso + ML385, OGD, ML385 + OGD, Iso + OGD, and Iso + ML385 + OGD groups. Lactate dehydrogenase activity (LDH) release and oxidative stress indexes were quantified. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect cell viability, Annexin V-FITC/propidium iodide (PI) staining to measure cell apoptosis, dichloro-dihydro-fluorescein diacetate (DCFH-DA) method to test reactive oxygen species (ROS), and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blotting to evaluate genes and protein expression. Results: Iso preconditioning reduced LDH release and inhibited cell cytotoxicity in OGD-induced cortical neurons, which was abolished by ML385. Iso preconditioning increased the Nrf2 nuclear translocation in cortical neurons. Meanwhile, Iso decreased the OGD-induced apoptosis with the down-regulations of Bax and Caspase-3 and the up-regulation of Bcl-2, which was reversed by ML385. OGD enhanced the level of ROS and malondialdehyde (MDA) in cortical neurons, but reduced the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), which were aggravated in ML385 + OGD group and mitigated in Iso + OGD group. No observable difference was found between OGD group and Iso + ML385 + OGD group regarding apoptosis-related proteins and oxidative stress-related indexes. Conclusion: Iso preconditioning up-regulated Nrf2 level to play its protective role in OGD-induced mouse cortical neuron injury.

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Kaempferol Ameliorates Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Ferroptosis by Activating Nrf2/SLC7A11/GPX4 Axis

Biomolecules ◽

10.3390/biom11070923 ◽

2021 ◽

Vol 11 (7) ◽

pp. 923

Author(s):

Yuan Yuan ◽

Yanyu Zhai ◽

Jingjiong Chen ◽

Xiaofeng Xu ◽

Hongmei Wang

Keyword(s):

Lipid Peroxidation ◽

Cell Death ◽

Antioxidant Capacity ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Nicotinamide Adenine Dinucleotide Phosphate ◽

Glucose Deprivation ◽

Oxygen Glucose Deprivation ◽

Related Factor ◽

Protective Effects

Kaempferol has been shown to protect cells against cerebral ischemia/reperfusion injury through inhibition of apoptosis. In the present study, we sought to investigate whether ferroptosis is involved in the oxygen-glucose deprivation/reperfusion (OGD/R)-induced neuronal injury and the effects of kaempferol on ferroptosis in OGD/R-treated neurons. Western blot, immunofluorescence, and transmission electron microscopy were used to analyze ferroptosis, whereas cell death was detected using lactate dehydrogenase (LDH) release. We found that OGD/R attenuated SLC7A11 and glutathione peroxidase 4 (GPX4) levels as well as decreased endogenous antioxidants including nicotinamide adenine dinucleotide phosphate (NADPH), glutathione (GSH), and superoxide dismutase (SOD) in neurons. Notably, OGD/R enhanced the accumulation of lipid peroxidation, leading to the induction of ferroptosis in neurons. However, kaempferol activated nuclear factor-E2-related factor 2 (Nrf2)/SLC7A11/GPX4 signaling, augmented antioxidant capacity, and suppressed the accumulation of lipid peroxidation in OGD/R-treated neurons. Furthermore, kaempferol significantly reversed OGD/R-induced ferroptosis. Nevertheless, inhibition of Nrf2 by ML385 blocked the protective effects of kaempferol on antioxidant capacity, lipid peroxidation, and ferroptosis in OGD/R-treated neurons. These results suggest that ferroptosis may be a significant cause of cell death associated with OGD/R. Kaempferol provides protection from OGD/R-induced ferroptosis partly by activating Nrf2/SLC7A11/GPX4 signaling pathway.

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