Mechanism on Banxia Xiexintang Inducing Ferroptosis in Gastric Cancer Cells Based on Nrf2/GPX4 Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo observe the effect of Banxia Xiexintang （BXT） on the proliferation of human gastric cancer HGC-27， MKN-45， and AGS cells and its mechanism. MethodCell counting kit-8 （CCK-8） was used to detect the effects of different concentrations of BXT-containing serum （5%， 10%， and 20%） on the proliferation of HGC-27， MKN-45， and AGS cells. A mitochondrial membrane potential probe （TMRE） was used to detect the expression of mitochondrial membrane potential in cells. A kit was used to detect iron ion （Fe2+） content， lipid peroxide （LPO）， and superoxide dismutase （SOD） activity. Western blot was used to detect the protein expression levels of glycogen synthase3β （GSK3β）， phosphorylated GSK3β （p-GSK3β）， nuclear factor E2 related factor 2 （Nrf2）， and glutathione peroxidase 4 （GPX4）. The real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of member 11 of the cystine/glutamic acid reverse transporter solute vector family 7 （SLC7A11）， member 2 of the heavy chain solute vector family 3 （SLC3A2）， transferrin receptor 3 （TFRC）， and tumor protein （TP）53. ResultCCK-8 results showed that BXT and capecitabine could significantly reduce the survival rate of three kinds of gastric cancer cells after treatment with drug-containing serum for 24 h （P<0.01）. After 48 h of intervention with drug-containing serum， the survival rate of three kinds of gastric cancer cells was significantly decreased in both the capecitabine group and the BXT group compared with the blank group. The BXT group was dose-dependent， with 20% BXT having the most significant effect （P<0.01）. In terms of biochemical indicators of ferroptosis， compared with the blank group， BXT and capecitabine significantly decreased the expression of mitochondrial membrane potential （P<0.01） and SOD activity （P<0.01） and significantly increased the contents of LPO and Fe2+ （P<0.01）， so as to improve the sensitivity of gastric cancer cells to ferroptosis. In terms of the Nrf2/GPX4 pathway， compared with the blank group， the BXT group could reduce the protein expressions of p-GSK3β， Nrf2， and GPX4 （P<0.01） in gastric cancer cells and increase mRNA expressions of SLC7A11 and SLC3A2 （P<0.05）. It could also increase the protein expression of GSK3β （P<0.01） and mRNA expression of TP53 and TFRC （P<0.05， P<0.01） in gastric cancer cells. Inhibition of the Nrf2/GPX4 pathway induces ferroptosis in gastric cancer cells. Compared with the capecitabine group， the 20% BXT group showed a more obvious effect. ConclusionBanxia Xiexintang can induce ferroptosis in gastric cancer cells HGC-27， MKN-45， and AGS by inhibiting the Nrf2/GPX4 pathway.

Effects of obacunone on renal interstitial fibrosis and ferroptosis in unilateral ureteral obstruction model mice / 中国药房

OBJECTVE To study the improvement effects of obacunone on renal interstitial fibrosis （RIF） in unilateral ureteral obstruction （UUO） model mice， and to investigate its mechanism based on ferroptosis mediated by nuclear factor erythroid 2- related factor 2（Nrf2）/glutathione peroxidase 4 （GPx4） signaling pathway. METHODS Thirty mice were randomly divided into sham operation group， model group， irbesartan group （positive control， 20 mg/kg）， obacunone low-dose and high-dose groups （10， 40 mg/kg）， with 6 mice in each group. Except for sham operation group， UUO model was established by ligation of unilateral ureter in other groups. After operation， administration groups were given intraperitoneal injection of relevant medicine， and sham operation group and model group were given intraperitoneal injection of constant volume of normal saline， once a day， for 7 consecutive days. The levels of creatinine （Cr） and blood urea nitrogen （BUN）， the content of malondialdehyde （MDA） and the activities of total superoxide dismutase （T-SOD） in serum and the concentration of Fe2+ in renal tissue were all detected. HE staining and Masson staining were performed to observe the morphology and the fibrosis of renal tissues. Immunohisto- chemical staining was used to determine expressions of the fibronectin （Fn）， α-smooth muscle actin （α-SMA）， GPx4 964083717@qq.com and Nrf2 in renal tissue. Western blot and real-time quantitative polymerase chain reaction （RT-qPCR） were used E-mail：834300205@qq.com to detect the protein and mRNA levels of Fn， α-SMA， Nrf2， GPx4 and SLC7A11 in the renal tissues. RESULTS Compared with sham operation group， serum levels of Cr and BUN， the concentration of Fe2+ in renal tissue， the protein and mRNA levels of Fn and α-SMA in model group were increased significantly （P＜0.05）， while the activity of T-SOD in serum， protein and mRNA expressions of Nrf2， GPx4， SLC7A11 in kidney tissue were significantly decreased （P＜0.05）； in the kidney tissue， the renal tubules were dilated， the collagen deposition was obvious， the fibrous bands were thicker and darker， and the renal interstitial inflammatory cells infiltrated significantly. After intervened with obacunone， the levels of above indexes （except for mRNA expression of SLC7A11 in obacunone low-dose group） in serum and renal tissue were reversed significantly （P＜0.05）， and pathological damage and collagen deposition of kidney tissue were alleviated. CONCLUSIONS Obacunone can improve renal interstitial fibrosis of UUO model mice， the mechanism of which may be associated with activating the Nrf2/GPx4 pathway and then inhibiting ferroptosis to relieve RIF in UUO model mice.

Novel perspective in transplantation therapy of mesenchymal stem cells: targeting the ferroptosis pathway / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Ex vivo culture-amplified mesenchymal stem cells (MSCs) have been studied because of their capacity for healing tissue injury. MSC transplantation is a valid approach for promoting the repair of damaged tissues and replacement of lost cells or to safeguard surviving cells, but currently the efficiency of MSC transplantation is constrained by the extensive loss of MSCs during the short post-transplantation period. Hence, strategies to increase the efficacy of MSC treatment are urgently needed. Iron overload, reactive oxygen species deposition, and decreased antioxidant capacity suppress the proliferation and regeneration of MSCs, thereby hastening cell death. Notably, oxidative stress (OS) and deficient antioxidant defense induced by iron overload can result in ferroptosis. Ferroptosis may inhibit cell survival after MSC transplantation, thereby reducing clinical efficacy. In this review, we explore the role of ferroptosis in MSC performance. Given that little research has focused on ferroptosis in transplanted MSCs, further study is urgently needed to enhance the in vivo implantation, function, and duration of MSCs.

Mechanism of HES1 regulating herceptin resistance in gastric cancer cells by ferroptosis / 药学学报

Drug resistance of cancer cells is the main causes of chemotherapy failure, and gene mutation or function loss is key factor to induce drug resistance. Previous studies have shown that hairy and enhancer of split 1 (HES1) is up-regulated in herceptin-resistant gastric cancer cells, and inhibition of its activity can reverse its resistance while the potential mechanism has not yet been elucidated. In this study, we employed CRISPR/Cas9 to establish HES1 knock-out cell line (△HES1/NCI N87R) to investigate the functions of HES1 in herceptin resistance of NCI N87R cells and its potential mechanisms. We investigated proteomics profiling of △HES1/NCI N87R cells based on quantitative proteomics. Gene ontology analysis was conducted by GeneSet Enrichment Analysis (GSEA) and Metascape database, and pathway enrichment analysis was done using GeneAnalytics database. The selected molecules were quantified by Western blot and some pathways were verified by using inhibitors. The results showed that the resistance to herceptin of △HES1/NCI N87R cells decreased compared to NCI N87R cells. Proteomic data demonstrated that the expression of 1 263 genes changed significantly in △HES1/NCI N87R cells, among which 761 genes were up-regulated while 502 ones down-regulated comparing with NCI N87R cells. Pathway analysis showed that ferroptosis, fatty acid β-oxidation, autophagy and glutathione metabolism, etc. exhibited notable changes in △HES1/NCI N87R cells. The functional studies showed that the levels of iron ion and malondialdehyde increased, and glutathione decreased in △HES1/NCI N87R cells. It was further found that Fer-1, a ferroptosis inhibitor, could reverse the expression of pTP53, solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) in △HES1/NCI N87R cell, and reduce the sensitivity of △HES1/NCI N87R cells to herceptin. It is suggested that HES1 regulated the resistance of NCI N87R cells to herceptin through TP53/SLC7A11/GPX4 signaling pathway, and targeting TP53/SLC7A11/GPX4 signal axis mediated by HES1 is a potential strategy to reverse herceptin resistance in gastric cancer.

Polysaccharide of Balanophora involucrata Hook. f. attenuates cell ferroptosis in rats with experimental liver injury through SLC7A11/GPX4 pathway / 药学学报

Polysaccharide of Balanophora involucrata Hook. f. (BPS), the major component of Balanophora involucrata Hook. f., was confirmed the protective effect on liver injury in our previous study. This research aimed to investigate the protective mechanism of BPS on experimental liver injury by attenuating cell ferroptosis through modulating solute carrier family 7 member 11/glutathione peroxidase 4 (SLC7A11/GPX4) pathway. The animal experiment was approved by the Experimental Animal Ethical Committee of Hubei Minzu University and all rats had received human care in compliance with the institutional animal care guidelines. Rats were given intraperitoneal injection of (D-galactosamine, D-GalN) solution (800 mg·kg-1) one time to establish the acute liver injury model. The results showed aspartate amino transferase (AST), alanine aminotransferase (ALT) and 4-hydroxynonenal (4-HNE) levels in serum were decreased, and the contents of reactive oxygen species (ROS), Fe2+, malondialdehyde (MDA) and lipid peroxide (LPO) in liver tissues also decreased and glutathione (GSH) level increased after BPS administration with 200 mg·kg-1. Besides, BPS reduced iron deposition and increased the expression of SLC7A11 and GPX4 proteins in liver tissue. In conclusion, BPS ameliorated experimental liver injury by alleviating cell ferroptosis through SLC7A11/GPX4 pathway. The present study pointed to the possibility of utilizing BPS for protection against liver injury in clinic.

Effects and mechanism of veratramine on the proliferation of human glioblastoma U251 cells / 中国药房

OBJECTIVE To explore the effects and potential mechanism of veratramine （VTM） on the proliferation of human glioblastoma U251 cells. METHODS The network pharmacology methods were adopted to screen the targets of ferroptosis related to the effects of VTM on glioblastoma， and to conduct gene ontology and Kyoto Encyclopedia of Genes and Genosomes enrichment analysis. Using U251 cells as the object， CCK-8 assay， the observation of cell morphological changes， DCFH-DA fluorescence probe method， FerroOrange fluorescence probe method and Western blot assay were used to validate the inhibitory effects of VTM on U251 cell proliferation and its possible mechanism. RESULTS Totally 462 targets of ferroptosis related to the effects of VTM on glioblastoma were screened out； they mainly enriched in biological processes such as oxidative stress and apoptosis， and cellular components such as cytoplasmic vesicles and mitochondrial membranes； they affected molecular functions such as iron ion （Fe2+） binding and DNA transcription processes， as well as iron death and phosphoinositide 3-kinase/protein kinase B signaling pathways. VTM with 40， 60， 80， 100， 120 and 140 μmol/L could significantly reduce the cell survival rate （P＜ 0.01）； VTM with 40， 80 and 120 μmol/L could cause cell atrophy and nuclear fragmentation， significantly inhibit the clone formation， increase the levels of intracellular reactive oxygen species （ROS） and Fe2+ levels， increase the expressions of nuclear factor-erythroid 2-related factor 2 （Nrf2） and heme oxygenase 1 （HO-1） protein to different extents， while down-regulate the expression of glutathione peroxidase 4 （GPX4） protein （P＜0.05 or P＜0.01）. CONCLUSIONS VTM can inhibit the proliferation of U251 cells， and promote the accumulation of intracellular ROS and Fe2+， thus inducing ferroptosis； its mechanism might be related to the regulation of the Nrf2/HO-1/GPX4 signaling pathway.

Effect and mechanism of ionizing radiation on ferroptosis in mouse hepatocytes / 中华放射肿瘤学杂志

Objective:To investigate the effect and mechanism of ionizing radiation on ferroptosis in mouse hepatocytes.Methods:Twenty-four C57BL/6J mice were divided into two groups by random number table method: healthy control group (control group, n=6) and irradiation group (whole liver was irradiated with a single dose of 30 Gy X-ray, n=18). Mice were sacrificed at 6, 24 and 72 h (6 mice per time point) after irradiation to obtain liver tissue and plasma samples. The contents of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in plasma were measured by automatic biochemical analyzer. The prothrombin time (PT) and activated partial thromboplastin time (APTT) were measured by automatic biochemical analyzer. Pathological changes of liver tissues were observed by hematoxylin-eosin (HE) staining. The iron deposition in liver tissues was detected by Prussian blue staining. The expression levels of 4-Hydroxynonenal (4HNE) and hepcidin in the liver were determined by immunohistochemical staining, and quantitative analysis was performed. Plasma malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, total antioxidant capacity (T-AOC) and glutathione (GSH) content were determined by microplate reader analysis according to the kit instructions. The expression levels of transferrin receptor 1 (TfR1), p53, solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) in the liver were measured by Western blot. Results:Compared with the control group, the plasma contents of ALT ( t=5.15, 5.47, both P<0.001) , AST at 6 and 24 h after irradiation were increased ( t=8.42, 2.50, both P<0.001), the plasma PT was prolonged ( t=3.12, P=0.011) and the APTT was shortened ( t=3.26, P=0.009) at 72 h after radiation in the irradiation group. Histopathological results showed that evident liver edema was observed at 6, 24 and 72 h after irradiation ( t=9.58, 10.09, 18.70, all P<0.001). Different degrees of iron deposition were observed ( t=8.57, 15.31, 32.11, all P<0.001). The infiltration of hepcidin positive cells was significantly increased after irradiation ( t=5.36, 13.17, 17.11, all P<0.001). The number of 4HNE positive cells was significantly increased ( t=18.86, 22.67, 9.12, all P<0.001). At the same time, ionizing radiation induced a significant increase in plasma MDA content ( t=4.36, 7.47, 8.22, all P<0.001), and a decrease in SOD ( t=4.52, 5.80, 7.60, all P<0.001), T-AOC ( t=13.24, 20.49, 24.96, all P<0.001) and GSH ( t=2.78, 6.07, 11.25, P=0.020, <0.001, <0.001), respectively. The expression level of TfR1 protein was significantly up-regulated ( t=3.46, 5.40, P=0.026, 0.006), whereas that of GPX4 protein was significantly down-regulated ( t=11.88, 30.63, both P<0.001) at 24 and 72 h after irradiation. At 6, 24 and 72 h after irradiation, the expression level of p53 protein was significantly up-regulated and maintained at a high level ( t=7.84, 4.25, 8.22, P=0.001, 0.013, 0.001), while that of SLC7A11 protein was significantly down-regulated ( t=9.29, 19.96, 9.09, all P<0.001). Conclusion:Ionizing radiation induces the ferroptosis in hepatocytes, and its mechanism may be related to the activation of p53-SLC7A11-GPX4 pathway.

Effects of ceftriaxone on Nrf2/GPX4 pathway and ferroptosis of cerebral cortex in early brain injury of rats with subarachnoid hemorrhage / 中华行为医学与脑科学杂志

Objective:To investigate the effects of ceftriaxone(CTX) on nuclear factor erythroid 2-related factor 2(Nrf2)/glutathione peroxidase 4(GPX4) pathway and ferroptosis in early brain injury in rats with subarachnoid hemorrhage(SAH).Methods:Forty-eight clean grade male SD rats were randomly divided into sham operation group (Sham group), SAH group, SAH+ CTX group and SAH+ CTX+ Nrf2 inhibitor group (SAH+ CTX+ ML385 group) according to the random number table with 12 rats in each group.Seven days before modeling, rats in SAH+ CTX+ ML385 group were injected intraperitoneally with ML385 (30 mg · kg -1) once a day for consecutive 7 days.And 5 days before modeling, rats in SAH+ CTX group and SAH+ CTX+ ML385 group were treated with CTX(200 mg · kg -1) by intraperitoneal injection once a day for five consecutive days.Rats in Sham group and SAH group were intraperitoneally injected with the same amount of 0.9% sodium chloride solution.After 24 hours of modeling, the neurological function score and brain tissue water content of rats in each group were measured.HE staining was used to observe the morphology of neurons in CA1 and CA3 regions of hippocampus.Prussian blue staining was used to observe the iron deposition in cerebral cortex.Spectrophotometer was used to determine the iron content, malonic dialdehyde(MDA) content, glutathione(GSH) content and GPX4 activity in cerebral cortex.Western blot was used to detect the expression levels of Nrf2 and GPX4 proteins in cerebral cortex.SPSS 23.0 was used for statistical analysis.One-way ANOVA was used to compare the mean of multiple groups of samples, and Dunnett- t test was used for further pairwise comparison between groups. Results:There was a statistically significant difference in the neurological function scores of rats in the four groups 24 hours after SAH ( F=48.40, P<0.001). The neurological function score of rats in the SAH group 24 hours after SAH was significantly lower than those in Sham group and SAH+ CTX group (both P<0.05). The brain water content of rats in the four groups 24 h after SAH was statistically significant ( F=49.61, P<0.001). The brain water content of rats in the SAH group 24 h after SAH was significantly higher than that in Sham group and SAH+ CTX group(both P<0.05). There was statistically significant differences in the number of neuronal necrosis in CA1 and CA3 regions of hippocampus in the four groups 24 hours after SAH ( F=17.44, 246.50, both P<0.001). The numbers of neuronal necrosis in CA1 and CA3 regions of hippocampus in SAH group were significantly higher than those in Sham group and SAH+ CTX group, and the numbers of neuronal necrosis in CA1 and CA3 regions of hippocampus in SAH+ CTX+ ML385 group were significantly higher than those in SAH+ CTX group (all P<0.05). Twenty-four hours after SAH, the amount of iron deposited in the cerebral cortex of rats in the four groups was statistically significant ( F=2 363.0, P<0.001). The iron deposition in the cerebral cortex of rats in the SAH group was significantly higher than those in Sham group and SAH+ CTX group (both P<0.05). There were significant differences in iron content, MDA content, GSH content and GPX4 activity in the cerebral cortex of the four groups 24 h after SAH( F=2 380.0, 1 322.0, 789.1, 815.5, all P<0.001). The content of iron and MDA in the cerebral cortex of rats in SAH group were significantly higher than those in Sham group, while the content of GSH and the activity of GPX4 were significantly lower than those in Sham group (all P<0.05). The content of iron and MDA in the cerebral cortex of rats in SAH+ CTX group were lower than those in SAH group, and the content of GSH and the activity of GPX4 were higher than those in SAH group (all P<0.05). At 24 h after SAH, the expression levels of Nrf2 and GPX4 protein in the cerebral cortex of the four groups were statistically significant ( F=888.7, 1 556.0, both P<0.001). The protein expression levels of Nrf2 (0.382±0.014) and GPX4 (0.329±0.019) in the cerebral cortex in SAH group were lower than those in Sham group ((0.746±0.009), (0.953±0.009)) (both P<0.05). The expression levels of Nrf2 (0.631±0.006) and GPX4 (0.833±0.008) protein in the cerebral cortex in the SAH+ CTX group were significantly higher than those in the SAH group (both P<0.05). The expression levels of Nrf2 (0.427±0.009) and GPX4 (0.525±0.011) protein in the cerebral cortex in SAH+ CTX+ ML385 group were significantly lower than those in SAH+ CTX group (both P<0.05). Conclusion:Ceftriaxone may inhibit ferroptosis during EBI in SAH rats by regulating Nrf2/GPX4 signal axis.

Triapine induces ferroptosis via ROS/GSH/GPX4 axis in A549 cells / 中国药理学通报

Aim To investigate the induction of ferroptosis of Triapine in non-small cell lung cancer cells A549, and its mechanism. Methods The effects of Triapine on the proliferation of A549 cells were assessed by MTT assay and colony formation assay; the effect of intracellular ROS levels of Triapine treated A549 cells was studied by DCFH-DA probe; the intracellular glutathione (GSH) and lipid peroxides (LPO) levels of A549 cells were detected by the kits after treating with Triapine; the effects of Triapine on the expression of glutathione peroxidase 4 (GPX4) in A549 cells were analyzed by Western blot; the changes of GPX4 level and cell viability were evaluated for the cells intervened with ROS inhibitor. Results Triapine could inhibit the proliferation of A549 cells, and the IC

Mechanism of cucurbitacin B suppresses proliferation of hepatocellular carcinoma Huh-7 cells via inducing ferroptosis / 中国药理学通报

Aim To study the effects of cucurbitacin B (Cu B) on proliferation of hepatocellular carcinoma Huh-7 cells and its mechanism. Methods CCK-8 was used to detect the survival rate of Huh-7 cells with different concentrations of Cu B. Huh-7 cells were treated with Cu B (0. 5, 1, 2 njnol; L

Ginsenoside Rgl inhibits neuronal ferroptosis caused by ischemic stroke through activating of Nrf2/xCT/GPX4 axis / 中国药理学通报

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

Shenqi Dihuang Decoction inhibits high-glucose induced ferroptosis of renal tubular epithelial cells via Nrf2/HO-1/GPX4 pathway / 中国中药杂志

This study aims to explore the effects of Shenqi Dihuang Decoction on high-glucose induced ferroptosis and the nuclear factor erythroid 2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)/glutathione peroxidase 4(GPX4) axis in human renal tubular epithelial cells(HK-2) and to clarify the underlying mechanism. The cell injury model was established by exposing HK-2 to high glucose, and the Shenqi Dihuang Decoction-medicated serum was prepared. The optimal concentration and intervention time of Shenqi Dihuang Decoction were determined. HK-2 were divided into normal, high glucose, and low-, medium-, and high-dose Shenqi Dihuang Decoction groups. After interventions, the cell proliferation rate in each group was determined and the cell morphology and mitochondrial ultrastructure were observed. Then, the levels of intracellular reactive oxygen species(ROS), ferrous ion(Fe~(2+)), glutathione(GSH), and malondialdehyde(MDA) and the protein levels of Nrf2, HO-1, GPX4, and xCT were measured. The optimal concentration and intervention time of Shenqi Dihuang Decoction-medicated serum were determined to be 10% and 24 h, respectively. Compared with the high glucose group, high-dose Shenqi Dihuang Decoction promoted the proliferation of HK-2. The cells in the low-, medium-, and high-dose Shenqi Dihuang Decoction groups presented tight arrangement, an increased cell count, improved morphology from a spindle-fiber shape to a cobblestone shape, and improved morphology and structure of mitochondrial membrane and cristae, compared with those in the high glucose group. Meanwhile, all the doses of Shenqi Dihuang Decoction inhibited ROS elevation to mitigate the peroxidation damage, lowered the Fe~(2+) and MDA levels and elevated the GSH level to inhibit lipid peroxidation, and activated the antioxidant pathway to upregulate the protein levels of Nrf2, HO-1, xCT, and GPX4. In conclusion, Shenqi Dihuang Decoction-medicated serum can inhibit high-glucose induced ferroptosis of HK-2 in vitro, which involves the antioxidant effect and the activation of the Nrf2/HO-1/GPX4 pathway.

Total triterpenes of Euphorbium alleviates rheumatoid arthritis via Nrf2/HO-1/GPX4 pathway / 中国中药杂志

This study aims to investigate the effect and mechanism of total triterpenes of Euphorbium in treating rheumatoid arthritis(RA). The rat model of RA was established with Freund's complete adjuvant(FCA). Male rats were randomly assigned into control, model, Tripterygium glycosides(7.5 mg·kg~(-1)), and low-, medium-, and high-dose total triterpenes of Euphorbium(32, 64, and 128 mg·kg~(-1), respectively) groups, with 10 rats in each group. In other groups except the control group, 0.2 mL FCA was injected into the right hind toe. Rats in the intervention groups were administrated with corresponding drugs by gavage, and the control group and the model group with the same volume of 0.5% CMC-Na solution once a day. During the treatment period, the swelling degree of the hind paw was measured and the arthritis was scored until day 30. At the end of drug administration, the pathological changes of the joint tissue were observed by hematoxylin-eosin staining. The content of malondialdehyde(MDA), glutathione(GSH), and Fe~(2+) and the activity of superoxide dismutase(SOD) in the joint tissue were measured by biochemical colorimetry. RT-PCR was performed to determine the mRNA levels of nuclear factor erythroid 2-related factor 2(Nrf2), glutathione peroxidase 4(GPX4), and acyl-CoA synthetase long chain family member 4(ACSL4) in the joint tissue. Western blot was employed to determine the protein levels of Nrf2, Kelch-like ECH-associated protein 1(Keap1), heme oxygenase-1(HO-1), NAD(P)H quinone oxidoreductase 1(NQO1), SOD2, GPX4, and ACSL4 in the joint tissue. The results showed that the treatment with Tripterygium glycosides(7.5 mg·kg~(-1)) and total triterpenes of Euphorbium(32, 64, and 128 mg·kg~(-1)) alleviated the swelling degree of bilateral hind limbs, decreased the arthritis score, reduced joint tissue lesions and the content of MDA and Fe~(2+) in the joint tissue, and increased GSH content and SOD activity. Furthermore, the interventions up-regulated the protein and mRNA levels of Nrf2 and GPX4, down-regulated the protein and mRNA levels of ACSL4, and up-regulated the protein levels of Keap1, NQO1, HO-1, and SOD2 in the Nrf2/HO-1/GPX4. In summary, the total triterpenes of Euphorbium can treat RA by inhibiting lipid peroxidation and abnormal ferroptosis, which may involve the Nrf2/HO-1/GPX4 signaling pathway.

Improvement effect and mechanism of matrine on experimental autoimmune encephalomyelitis mice / 中国药房

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.

Erianin inhibits oral cancer cell growth, migration, and invasion via the Nrf2/HO-1/ GPX4 pathway

Objective: To evaluate the effect of erianin on the viability, migration, and invasion of KB cells and elucidate its underlying mechanisms. Methods: Cell Counting Kit-8, colony formation, wound healing, and Transwell assays were used to determine the proliferation, migration, and invasion of oral cancer KB cells. Furthermore, malondialdehyde (MDA) and glutathione (GSH) levels were determined. Fluorescent probes were used to detect changes in intracellular reactive oxygen species and iron ions. Additionally, the expressions of ferroptosis-related proteins, NF-E2-related factor 2 (Nrf2), ferritin heavy chain 1 (FTH1), heme oxygenase 1 (HO-1), and glutathione peroxidase 4 (GPX4) were analyzed by Western blotting assays. Results: Erianin induced ferroptosis and inhibited the proliferation, migration, and invasion of KB cells. Moreover, erianin decreased GSH level, increased MDA level, elevated intracellular ROS and Fe

Dexmedetomidine attenuates ferroptosis through regulation of Nrf2 on HT22 cells with hypoxia/reoxyge nation / 中国药理学通报

Aim To investigate the effects of Dexmedetomidine(DEX)on HT22 cells with hypoxia/reoxygenation based on ferroptosis and the underlying mechanism.Methods HT22 cells were used to prepare H/R injury model.In order to investigate the optimal concentration of DEX, cells were divided into five groups: control group, H/R group, low concentration(H/R+DEX2.5, 2.5 μmol·L-1), medium concentration(H/R+DEX5, 5 μmol·L-1), high concentration(H/R+DEX10, 10 μmol·L-1)DEX intervention H/R group, and the survival rates of cells were detected by MTT assay.To investigate the mechanism of the protective effects on HT22 cells with H/R injury, HT22 cells were divided into four groups: control group, H/R group, H/R+DEX5 group, and H/R+DEX5 +ML385 group.The survival rates of cells were detected by MTT assay; the levels of Fe2+ were detected by FerroOrange fluorescent probe; the C11BODIPY581/591 was used to detect the change of lipid ROS on the cells; MDA and reduced glutathione kits were used to detect the content of MDA and GSH of cells respectively.The expressions of Nrf2, GPX4, TFR1 and SLC7A11 were detected by Western blot.Results Compared with control group, the survival rate of cells, the content of GSH, and the expression of Nrf2, GPX4 and SLC7A11 all significantly decreased(all P<0.05), the level of lipid ROS, the content of MDA, the level of Fe2+, and the expression of TFR1 all significantly increased in H/R group(all P<0.01).Compared with H/R group, the survival rate of cells, the content of GSH, and the expression of Nrf2, GPX4 and SLC7A11 significantly increased(all P<0.05), the level of lipid ROS, the content of MDA, the level of Fe2+, and the expression of TFR1 significantly decreased with the treatment of DEX(all P<0.05).Compared with H/R+DEX group, the survival rate of cells, the content of GSH, and the expression of Nrf2, GPX4 and SLC7A11 markedly decreased(all P<0.05), the lipid ROS, MDA and Fe2+, and the expression of TFR1 significantly increased in H/R+DEX+ML385 group(all P<0.05).Conclusions DEX can reduce H/R injury on HT22 cells by inhibiting ferroptosis, and the mechanism might be related to the promotive expression of Nrf2.

Berberine inhibits erastin-induced ferroptosis of mouse hippocampal neuronal cells possibly by activating the Nrf2-HO-1/GPX4 pathway / 南方医科大学学报

OBJECTIVE@#To explore the mechanism by which berberine inhibits ferroptosis of mouse hippocampal neuronal cells (HT22).@*METHODS@#Cultured HT22 cells were pretreated with 30 or 60 μmol/L berberine for 2 h before exposure to 0.5 μmol/L erastin for 8 h, and the cell proliferation, intracellular ferric iron level, changes in intracellular reactive oxygen species (ROS) and cell apoptosis were detected using CCK-8, Fe2+ fluorescent probe, fluorescent dye (DAPI) and fluorescent probe (H2DCFH-DA). RT-qPCR and Western blotting were used to detect the mRNA and protein expressions of Nrf2, HO-1 and GPX4 in the cells. We further tested the effects of treatments with 2 μmol/L ML385 (a Nrf2 inhibitor), 60 μmol/L berberine and erastin in the cells to explore the protective mechanism of berberine against erastin-induced ferroptosis in the neuronal cells.@*RESULTS@#Treatment with 0.5 μmol/L erastin significantly lowered the viability of HT22 cells (P < 0.05) and increased the production of ROS, cell apoptosis rate and ferric iron level (P < 0.05). Pretreatment with 30 and 60 μmol/L berberine both significantly increased the vitality of erastin-exposed cells (P < 0.05) and lowered the levels of intracellular ROS and ferric iron content (P < 0.05). RT-qPCR and Western blotting showed that berberine obviously promoted the expressions of Nrf2, HO-1 and GPX4 in the cells (P < 0.05), and treatment with ML385 significantly inhibited the Nrf2-HO-1/GPX4 pathway, increased intracellular ROS and ferric iron contents and mitigated the protective effect of berberine against erastin-induced ferroptosis (P < 0.05).@*CONCLUSION@#Berberine can inhibit erastin-induced ferroptosis in HT22 cells possibly by activating the Nrf2-HO-1/ GPX4 pathway.

A novel anticancer property of Lycium barbarum polysaccharide in triggering ferroptosis of breast cancer cells / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

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.

Ferroptosis, radiotherapy, and combination therapeutic strategies

Ferroptosis, an iron-dependent form of regulated cell death driven by peroxidative damages of polyunsaturated-fatty-acid-containing phospholipids in cellular membranes, has recently been revealed to play an important role in radiotherapy-induced cell death and tumor suppression, and to mediate the synergy between radiotherapy and immunotherapy. In this review, we summarize known as well as putative mechanisms underlying the crosstalk between radiotherapy and ferroptosis, discuss the interactions between ferroptosis and other forms of regulated cell death induced by radiotherapy, and explore combination therapeutic strategies targeting ferroptosis in radiotherapy and immunotherapy. This review will provide important frameworks for future investigations of ferroptosis in cancer therapy.