17β-Estradiol prevents cell death and mitochondrial dysfunction by an estrogen receptor-dependent mechanism in astrocytes after oxygen–glucose deprivation/reperfusion

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.

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Estradiol abolishes reduction in cell death by the opioid agonist Met5-enkephalin after oxygen glucose deprivation in isolated cardiomyocytes from both sexes

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01018.2007 ◽

2008 ◽

Vol 295 (1) ◽

pp. H409-H415 ◽

Cited By ~ 3

Author(s):

Matthias J. Merkel ◽

Lijuan Liu ◽

Zhiping Cao ◽

William Packwood ◽

Patricia D. Hurn ◽

...

Keyword(s):

Cell Death ◽

Estrogen Receptor ◽

Cell Survival ◽

Glucose Deprivation ◽

Oxygen Glucose Deprivation ◽

Dependent Manner ◽

Opioid Agonist ◽

Independent Manner ◽

Increase Cell Survival

There is evidence for differences in the response to the treatment of cardiovascular disease in men and women. In addition, there are conflicting results regarding the effectiveness of pharmacologically induced protection or ischemic preconditioning in females. We investigated whether the ability of Met5-enkephalin (ME) to reduce cell death after oxygen-glucose deprivation (OGD) is influenced by the presence of 17β-estradiol (E2) in a nitric oxide (NO)- and estrogen receptor-dependent manner. On postnatal day 7 to 8, murine cardiomyocytes from wild-type or inducible NO synthase (iNOS) knockout mice were separated by sex, isolated by collagenase digestion, cultured for 24 h, and subjected to 90 min OGD and 180 min reoxygenation at 37°C ( n = 4 to 5 replicates). Cell cultures were incubated in E2 for 15 min or 24 h before OGD. ME was used to increase cell survival. Cell death was assessed by propidium iodide. More than 300 cells were examined for each treatment. Data are presented as means ± SE. As a result, in both sexes, ME-induced cell survival was lost in the presence of E2, and the ability of ME to improve cell survival was restored after treatment with the estrogen receptor antagonist ICI-182780. Furthermore, iNOS was necessary for ME to increase cell survival following OGD in vitro. We conclude that ME-induced reduction in cell death is abolished by E2 in a sex-independent manner via activation of estrogen receptors, and this interaction is dependent on iNOS.

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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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