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AIM: To investigate the occurrence and possible mechanism of blue light-induced ferroptosis in retinal pigment epithelial cells.METHODS: ARPE-19 cells cultured in vitro were irradiated by 405 nm blue light at 50 mW/cm2 irradiance with different duration and were divided into control, 16.3J/cm2, 32.6J/cm2, and 65.2J/cm2 groups; the 65.2J/cm2 group was defined as the high-level blue light irradiation group and cells were further divided into control, high-level blue light irradiation group and high-level blue light irradiation + ferroptosis inhibitor group. CCK-8 assay was used to detect cell viability, commercial kits were used to detect intracellular glutathione(GSH), ferrous iron and malondialdehyde(MDA)concentration, and Western blot was used to detect the relative expression of glutathione peroxidase 4(GPX4)and xCT proteins in cells.RESULTS: The decrease of ARPE-19 cell viability caused by blue light irradiation was dose-dependent, and the reduction of intracellular GSH concentration, the increase of ferrous iron concentration and MDA concentration were all caused by high-level blue light irradiation(all P<0.05); the ferroptosis inhibitor partially restored cell viability and recovered intracellular GSH, reduced concentrations of MDA and ferrous iron in the blue light irradiation group(all P<0.05). The relative expressions of GPX4 and xCT proteins were significantly decreased in the blue light irradiation group, and such change was alleviated by the ferroptosis inhibitor(P<0.05).CONCLUSION: Blue light irradiation may induce ferroptosis in RPE cells by targeting the xCT and GPX4-associated antioxidant pathways.
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Aim To study the inhibitory effect of ginsenoside Rgl on neuronal ferroptosis after ischemic stroke and its mechanism. Methods A model of oxygen glucose deprivation/reoxygenation (OGD/R) was established in HT22 cells, and the effect of Rgl on the viability of HT22 cells after OGD/R injury was detected by CCK-8. The effect of Rgl on ferroptosis in HT22 cells after OGD/R injury was detected by the test of ferroptosis markers GSH/GSSG, SOD, MDA, and Fe
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OBJECTIVE To investigate whether matrine exerts improvement effect on experimental autoimmune encephalomyelitis （EAE） mice by regulating ferroptosis pathway. METHODS Totally 30 female C57BL/6 mice were randomly assigned into normal group， model group and matrine group， with 10 mice in each group. Model group and matrine group were given antigen emulsion containing inactivated Mycobacterium tuberculosis and MOG35-55 to induce EAE model. Matrine group was injected with Matrine injection （50 mg/kg） intraperitoneally since the 7th day after immunization； normal group and model group were given constant volume of normal saline intraperitoneally， once a day， since 18th day after immunization. The neurofunctional score of mice was recorded， and hematoxylin and eosin staining and Luxol fast blue staining were used to observe inflammatory cell infiltration and demyelination in spinal cord tissue. The quantitative reverse transcription PCR and Western blot assay were performed to determine the mRNA expressions of transferrin receptor 1 （TFR1）， nuclear receptor coactivator 4 （NCOA4） and hephaestin （Heph）， and the protein expressions of system Xc－ （xCT） and glutathione peroxidase 4 （GPx4）. RESULTS Compared with normal group， accumulative neurofunctional score was significantly increased in model group （P＜0.01）； inflammatory cell infiltration and demyelination were obvious in spinal cord tissue， and related scores were increased significantly （P＜0.01）. The mRNA expressions of TFR1 and NCOA4 in myelin tissue were up-regulated significantly， while the mRNA expression of Heph and the protein expressions of xCT and GPx4 were down-regulated significantly （P＜0.05 or P＜0.01）. Compared with model group， above indexes of matrine group were all improved significantly （P＜0.05 or P＜0.01）. CONCLUSIONS Matrine can improve EAE mice， the mechanism of which may be associated with regulating iron metabolism pathway and xCT/GPx4 pathway in ferroptosis.
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Breast cancer is one of the most malignant tumors and is associated with high mortality rates among women. Lycium barbarum polysaccharide (LBP) is an extract from the fruits of the traditional Chinese herb, L. barbarum. LBP is a promising anticancer drug, due to its high activity and low toxicity. Although it has anticancer properties, its mechanisms of action have not been fully established. Ferroptosis, which is a novel anticancer strategy, is a cell death mechanism that relies on iron-dependent lipid reactive oxygen species (ROS) accumulation. In this study, human breast cancer cells (Michigan Cancer Foundation-7 (MCF-7) and MD Anderson-Metastatic Breast-231 (MDA-MB-231)) were treated with LBP. LBP inhibited their viability and proliferation in association with high levels of ferroptosis. Therefore, we aimed to ascertain whether LBP reduced cell viability through ferroptosis. We found that the structure and function of mitochondria, lipid peroxidation, and expression of solute carrier family 7 member 11 (SLC7A11, also known as xCT, the light-chain subunit of cystine/glutamate antiporter system Xc-) and glutathione peroxidase 4 (GPX4) were altered by LBP. Moreover, the ferroptosis inhibitor, Ferrostatin-1 (Fer-1), rescued LBP-induced ferroptosis-associated events including reduced cell viability and glutathione (GSH) production, accumulation of intracellular free divalent iron ions and malondialdehyde (MDA), and down-regulation of the expression of xCT and GPX4. Erastin (xCT inhibitor) and RSL3 (GPX4 inhibitor) inhibited the expression of xCT and GPX4, respectively, which was lower after the co-treatment of LBP with Erastin and RSL3. These results suggest that LBP effectively prevents breast cancer cell proliferation and promotes ferroptosis via the xCT/GPX4 pathway. Therefore, LBP exhibits novel anticancer properties by triggering ferroptosis, and may be a potential therapeutic option for breast cancer.
Subject(s)
Female , Humans , Breast Neoplasms/drug therapy , Drugs, Chinese Herbal/pharmacology , Ferroptosis , Glutathione/metabolism , Iron/metabolismABSTRACT
The cystine/glutamate antiporter SLC7A11 (also commonly known as xCT) functions to import cystine for glutathione biosynthesis and antioxidant defense and is overexpressed in multiple human cancers. Recent studies revealed that SLC7A11 overexpression promotes tumor growth partly through suppressing ferroptosis, a form of regulated cell death induced by excessive lipid peroxidation. However, cancer cells with high expression of SLC7A11 (SLC7A11
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Objective To investigate influences of estrogen-related receptor α(ERRα) on pulmonary vascular endothelium of rats undergoing sepsis. Methods Male Sprague-Dawley (SD) rats were divided into four groups according to the random number table method (12 in each group): normal control group (NC group), sham operation group (Sham group), sepsis model caused by cecal ligation and puncture (CLP) group (CLP group), XCT790 intervention group (XCT790 group, given the XCT790 2.5 mg/kg via intraperitoneal injection 30 minutes before CLP). After 24 hours, rats were sacrificed and the organs were harvested. The pathological changes of lung tissue were observed using hematoxylin and eosin (HE) staining, and the ultrastructural changes of lung tissue were observed by double staining of uranium citrate with lead acetate, the degree of apoptosis of pulmonary capillary endothelial cells were observed by TdT-mediated dUTP nike end labeling stain (TUNEL), the permeability of lung vascular endothelial was detected by Evans blue (EB) staining, the levels of serum cytokines were detected by enzyme linked immunosorbent assay (ELISA), and white blood cell count in bronchial alveolar lavage fluid (BALF) was detected. Results Compared with NC group and Sham group, the CLP group and XCT790 group had severe pathological damage and increased lung tissue permeability, the levels of serum cytokines and white blood cell count in BALF were increased. Compared with CLP group, the pathological changes of lung tissue, the degree of ultrastructural damage of lung tissue, the degree of apoptosis of lung capillary endothelial cells in XCT790 group further intensified, the permeability of lung endothelial barrier further increased [the content of EB (μg/g): 116.00±15.46 vs. 60.19±19.79, P < 0.05], and the level of serum cytokines further increased [interleukin-1β(IL-1β, ng/L): 71.38±4.01 vs. 56.58±2.45, interleukin-6 (IL-6, ng/L): 741.62±88.94 vs. 534.22±72.70, tumor necrosis factor-α(TNF-α, ng/L):188.55±7.41 vs. 143.33±11.27, all P < 0.05], the white blood cell count in the BALF increased further (×104/L:193.79±27.46 vs. 99.34±36.41, P < 0.05). Conclusion ERRα can aggravate inflammation in sepsis rats, destroy lung tissue and increase pulmonary permeability.
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Objective To identify the mechanisms underlying xCT deficiency by high-resolution proteomic analysis of differential protein expression in Sut and wild melanocytes .Methods The proteins,extracted from Sut and wild melano-cytes,were analyzed by two dimensional electrophoresis and PDQuest software .Subsequent MALDI-TOF mass spectrometry analysis was carried out .The protein identification was based on peptide mass fingerprint combined with the pI and the rela -tive molecular mass ( Mr) .Sequence coverage was performed with the Peptldent software on the NCBnlm website .Also,the autophagy marker protein LC3-Ⅱ, and the autophagic cell death marker protein Beclin 1 were detected by Western blotting . Results and Conclusion Twenty apparently upregulated or downregulated proteins were identified .Strikingly, important modifications in regulators of trafficking and organization of vesicles and autophagy ( Anxa3; Hist 1h2bk, NDRG1, and CaM) and in regulators of invasion and metastasis of carcinoma (S100A-4;S100A-6 and vimentin)are likely to account for dysfunctions in cell viability and cell-extracellular adhesion .These results indicate that the proteins regulating autophagy , vesicles trafficking and MAP kinase related pathways are activated and play a role in xCT-deficiency .
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Objective To investigate the mechanism of Sut melanocytes growth inhibition in response to xCT -deficiency. Methods TTotal proteins were extracted from xCT-deficient Sut melanocytes and wild melanocytes, respectively, and were separated by 2-dimensional electrophoresis. Altered expression profile of proteins of Sut melanocytes was analyzed by PDQuest software and compared with that of wild melanocytes.Proteins with significant change were chosen to be identified by mass spectrometry and database query.Results Twenty proteins in Sut melanocytes altered significantly compared with wild melanocytes. Ten of the proteins were up-regulated, while the other tens were down-regulated. Four proteins from both up-regulated and down-regulated were identified respectively: up-regulated proteins were Tubulin alpha-1b, S100-A6,Nucleoside, S-formylglutathione, and down-regulated proteins were Calumenin,NDRG1 ,DPYSL2, 14kDa unknown protein. Conclusion The identification of the xCT-deficiency related proteins may provide supporting evidence for the mechanism research of Sut melanocytes' growth inhibition caused by xCT-deficiency.
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This paper introduces X-ray intensity, absorbed dose, equivalent dose of X- CT radiation and the interaction between X-ray and human body. The theory and formulas related to the measurement of X-CT radiation dose are also involved in.