Selenium deficiency exacerbates ROS/ER stress mediated pyroptosis and ferroptosis induced by bisphenol A in chickens thymus.

Bisphenol A (BPA) is an industrial pollutant that can cause immune impairment. Selenium acts as an antioxidant, as selenium deficiency often accompanies oxidative stress, resulting in organ damage. This study is the first to demonstrate that BPA and/or selenium deficiency induce pyroptosis and ferroptosis-mediated thymic injury in chicken and chicken lymphoma cell (MDCC-MSB-1) via oxidative stress-induced endoplasmic reticulum (ER) stress. We established a broiler chicken model of BPA and/or selenium deficiency exposure and collected thymus samples as research subjects after 42 days. The results demonstrated that BPA or selenium deficiency led to a decrease in antioxidant enzyme activities (T-AOC, CAT, and GSH-Px), accumulation of peroxides (H2O2 and MDA), significant upregulation of ER stress-related markers (GRP78, IER 1, PERK, EIF-2α, ATF4, and CHOP), a significant increase in iron ion levels, significant upregulation of pyroptosis-related gene (NLRP3, ASC, Caspase1, GSDMD, IL-18 and IL-1ß), significantly increase ferroptosis-related genes (TFRC, COX2) and downregulate GPX4, HO-1, FTH, NADPH. In vitro experiments conducted in MDCC-MSB-1 cells confirmed the results, demonstrating that the addition of antioxidant (NAC), ER stress inhibitor (TUDCA) and pyroptosis inhibitor (Vx765) alleviated oxidative stress, endoplasmic reticulum stress, pyroptosis, and ferroptosis. Overall, this study concludes that the combined effects of oxidative stress and ER stress mediate pyroptosis and ferroptosis in chicken thymus induced by BPA exposure and selenium deficiency.

Auriculasin induces mitochondrial oxidative stress and drives ferroptosis by inhibiting PI3K/Akt pathway in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) accounts for the majority of cases of lung cancer with poor outcomes. Auriculasin is a prenylated isoflavone abundant in the root of F. philippinensis with multiple pharmacological effects, including anticancer role. However, its roles in NSCLC remain largely unknown. NSCLC A549 cells were treated with auriculasin in vitro, and used to induce xenograft models. Cell viability was detected via CCK-8 assay. Mitochondrial oxidative stress was analyzed by JC-1 staining, ROS staining, and levels of MDA, SOD and GSH. Ferroptosis was assessed via iron content, and levels of ACSL4, PTGS2, FSP1 and GPX4. The phosphorylation levels of PI3K and Akt were measured by western blot. Auriculasin reduced NSCLC cell viability. Auriculasin promoted mitochondrial oxidative stress by reducing mitochondrial membrane potential, SOD and GSH levels, and enhancing ROS and MDA contents. In addition, auriculasin induced ferroptosis via increasing iron, ACSL4 and PTGS3 levels, and decreasing FSP1 and GPX4 levels. Furthermore, the potential targets of auriculasin in NSCLC were enriched in PI3K/Akt signaling. Auriculasin blunted PI3K/Akt pathway activation by blocking the phosphorylation. Activated PI3K/Akt signaling by activator 740Y-P reversed the effects of auriculasin on mitochondrial oxidative stress and ferroptosis. Finally, auriculasin reduced NSCLC cell growth in xenograft models. Auriculasin facilitates mitochondrial oxidative stress and induces ferroptosis through inhibiting PI3K/Akt pathway in NSCLC.

ß-Caryophyllene Confers Cardioprotection by Scavenging Radicals and Blocking Ferroptosis.

Ferroptosis is a form of regulated cell death triggered by iron-dependent lipid peroxidation and has been associated with heart diseases. However, there are currently no approved drugs that specifically inhibit ferroptosis in clinical practice, which largely limits the translational potential of this novel target. Here, we demonstrated that ß-caryophyllene (BCP; 150 µM), a natural dietary cannabinoid, protects cardiomyocytes against ferroptotic cell death induced by cysteine deprivation or glutathione peroxidase 4 (GPX4) inactivation. Moreover, BCP preserved the mitochondrial morphology and function during ferroptosis induction. Unexpectedly, BCP supported ferroptosis resistance independent of canonical antiferroptotic pathways. Our results further suggested that BCP may terminate radical chain reactions through interactions with molecular oxygen, which also explains why its oxidation derivative failed to suppress ferroptosis. Finally, oral BCP administration (50 mg/kg, daily) significantly alleviated doxorubicin (15 mg/kg, single i.p. injection)-induced cardiac ferroptosis and cardiomyopathy in mice. In conclusion, our data revealed the role of BCP as a natural antiferroptotic compound and suggest pharmacological modification based on BCP as a promising therapeutic strategy for treating ferroptosis-associated heart disorders.

Insights from CD71 presentation and serum lipid peroxidation in myasthenia gravis - A small cohort study.

Myasthenia gravis (MG) is a multifaceted autoimmune disorder affecting the postsynaptic neuromuscular junction. In this study, we examined CD4+ and CD8+ T lymphocyte levels and ratios within peripheral blood mononuclear cells (PBMCs) in MG patients. Additionally, we assessed lymphocytes for the expression of CD71, which functions as a transferrin receptor mediating the uptake of iron into the cells. Building on recent discussions regarding CD20 depletion treatments in MG, we also scrutinized lymphocytes for CD20 expression. Comparative analyses were conducted among healthy controls, newly diagnosed MG patients, those undergoing pyridostigmine treatment alone, and MG patients receiving combination therapies. In the patients, the ratio of CD3+CD4+ T lymphocytes to CD3+ T lymphocytes was found to be decreased compared to the healthy controls, while the ratio of CD3+CD8+ cells to CD3+CD4+ cells increased. An increase in the percentage of CD71-expressing lymphocytes was observed in MG patients compared to the healthy control group, while CD20+ lymphocytes exhibited no statistical changes. Moreover, heightened serum lipid peroxidation levels were found in MG patients. These results suggest a possible relationship between iron metabolism, levels of CD71-expressing cells, and lipid peroxidation in MG. Conversely, pyridostigmine treatment reduced the levels of CD71-expressing cells and lipid peroxidation, suggesting potential immunomodulatory and antioxidant impacts of pyridostigmine in MG, either directly or indirectly.

Chronic cold stress promotes inflammation and ER stress via inhibiting GLP-1R signaling, and exacerbates the risk of ferroptosis in the liver and pancreas.

The cold climates in autumn and winter threatens human health. The aim of this study was to reveal the effects of prolonged cold exposure on the liver and pancreas based on GLP-1R signaling, oxidative stress, endoplasmic reticulum (ER) stress and ferroptosis by Yorkshire pig models. Yorkshire pigs were divided into the control group and chronic cold stress (CCS) group. The results showed that CCS induced oxidative stress injury, activated Nrf2 pathway and inhibited the expression of GLP-1R in the liver and pancreas (P<0.05). The toll-like receptor 4 (TLR4) pathway was activated in the liver and pancreas, accompanied by the enrichment of IL-1ß and TNF-α during CCS (P<0.05). Moreover, the kinase RNA-like endoplasmic reticulum kinase (PERK), inositol requiring kinase 1 (IRE1), X-box-binding protein 1 (XBP1) and eukaryotic initiation factor 2α (eIF2α) expression in the liver and pancreas was up-regulated during CCS (P<0.05). In addition, CCS promoted the prostaglandin-endoperoxide synthase 2 (PTGS2) expression and inhibited the ferritin H (FtH) expression in the liver. Summarily, CCS promotes inflammation, ER stress and apoptosis by inhibiting the GLP-1R signaling and inducing oxidative stress, and exacerbates the risk of ferroptosis in the liver and pancreas.

Targeting SMYD2 promotes ferroptosis and impacts the progression of pancreatic cancer through the c-Myc/NCOA4 axis-mediated ferritinophagy.

BACKGROUND: Pancreatic cancer (PC) is characterized by a poor prognosis and limited treatment options. Ferroptosis plays an important role in cancer, SET and MYND domain-containing protein 2 (SMYD2) is widely expressed in various cancers. However, the role of SMYD2 in regulating ferroptosis in PC remains unexplored. This study aimed to investigate the role of SMYD2 in mediating ferroptosis and its mechanistic implications in PC progression. METHODS: The levels of SMYD2, c-Myc, and NCOA4 were assessed in PC tissues, and peritumoral tissues. SMYD2 expression was further analyzed in human PC cell lines. In BxPC3 cells, the expression of c-Myc, NCOA4, autophagy-related proteins, and mitochondrial morphology, was evaluated following transfection with si-SMYD2 and treatment with autophagy inhibitors and ferroptosis inhibitors. Ferroptosis levels were quantified using flow cytometry and ELISA assays. RNA immunoprecipitation was conducted to elucidate the interaction between c-Myc and NCOA4 mRNA. A xenograft mouse model was constructed to validate the impact of SMYD2 knockdown on PC growth. RESULTS: SMYD2 and c-Myc were found to be highly expressed in PC tissues, while NCOA4 showed reduced expression. Among the PC cell lines studied, BxPC3 cells exhibited the highest SMYD2 expression. SMYD2 knockdown led to decreased c-Myc levels, increased NCOA4 expression, reduced autophagy-related protein expression, mitochondrial shrinkage, and heightened ferroptosis levels. Additionally, an interaction between c-Myc and NCOA4 was identified. In vivo, SMYD2 knockdown inhibited tumor growth. CONCLUSIONS: Targeting SMYD2 inhibits PC progression by promoting ferritinophagy-dependent ferroptosis through the c-Myc/NCOA4 axis. These findings provide insights into potential diagnostic and therapeutic strategies for PC.

Aristolochic acids-hijacked p53 promotes liver cancer cell growth by inhibiting ferroptosis.

Aristolochic acids (AAs) have been identified as a significant risk factor for hepatocellular carcinoma (HCC). Ferroptosis is a type of regulated cell death involved in the tumor development. In this study, we investigated the molecular mechanisms by which AAs enhanced the growth of HCC. By conducting bioinformatics and RNA-Seq analyses, we found that AAs were closely correlated with ferroptosis. The physical interaction between p53 and AAs in HepG2 cells was validated by bioinformatics analysis and SPR assays with the binding pocket sites containing Pro92, Arg174, Asp207, Phe212, and His214 of p53. Based on the binding pocket that interacts with AAs, we designed a mutant and performed RNA-Seq profiling. Interestingly, we found that the binding pocket was responsible for ferroptosis, GADD45A, NRF2, and SLC7A11. Functionally, the interaction disturbed the binding of p53 to the promoter of GADD45A or NRF2, attenuating the role of p53 in enhancing GADD45A and suppressing NRF2; the mutant did not exhibit the same effects. Consequently, this event down-regulated GADD45A and up-regulated NRF2, ultimately inhibiting ferroptosis, suggesting that AAs hijacked p53 to down-regulate GADD45A and up-regulate NRF2 in HepG2 cells. Thus, AAs treatment resulted in the inhibition of ferroptosis via the p53/GADD45A/NRF2/SLC7A11 axis, which led to the enhancement of tumor growth. In conclusion, AAs-hijacked p53 restrains ferroptosis through the GADD45A/NRF2/SLC7A11 axis to enhance tumor growth. Our findings provide an underlying mechanism by which AAs enhance HCC and new insights into p53 in liver cancer. Therapeutically, the oncogene NRF2 is a promising target for liver cancer.

A novel mechanism of ferroptosis inhibition-enhanced atherosclerotic plaque stability: YAP1 suppresses vascular smooth muscle cell ferroptosis through GLS1.

Atherosclerosis is a leading cause of cardiovascular diseases (CVDs), often resulting in major adverse cardiovascular events (MACEs), such as myocardial infarction and stroke due to the rupture or erosion of vulnerable plaques. Ferroptosis, an iron-dependent form of cell death, has been implicated in the development of atherosclerosis. Despite its involvement in CVDs, the specific role of ferroptosis in atherosclerotic plaque stability remains unclear. In this study, we confirmed the presence of ferroptosis in unstable atherosclerotic plaques and demonstrated that the ferroptosis inhibitor ferrostatin-1 (Fer-1) stabilizes atherosclerotic plaques in apolipoprotein E knockout (Apoe-/-) mice. Using bioinformatic analysis combining RNA sequencing (RNA-seq) with single-cell RNA sequencing (scRNA-seq), we identified Yes-associated protein 1 (YAP1) as a potential key regulator of ferroptosis in vascular smooth muscle cells (VSMCs) of unstable plaques. In vitro, we found that YAP1 protects against oxidized low-density lipoprotein (oxLDL)-induced ferroptosis in VSMCs. Mechanistically, YAP1 exerts its anti-ferroptosis effects by regulating the expression of glutaminase 1 (GLS1) to promote the synthesis of glutamate (Glu) and glutathione (GSH). These findings establish a novel mechanism where the inhibition of ferroptosis promotes the stabilization of atherosclerotic plaques through the YAP1/GLS1 axis, attenuating VSMC ferroptosis. Thus, targeting the YAP1/GLS1 axis to suppress VSMC ferroptosis may represent a novel strategy for preventing and treating unstable atherosclerotic plaques.

Acute liver failure: A clinically severe syndrome characterized by intricate mechanisms.

Acute liver failure presents as a clinical syndrome characterized by swift deterioration and significant mortality rates. Its underlying mechanisms are intricate, involving intricate interplays between various cells. Given the current scarcity of treatment options, there's a pressing need to diligently uncover the disease's core mechanisms and administer targeted therapies accordingly.

An update on the role of ferroptosis in the pathogenesis of osteoporosis.

Ferroptosis is a novel form of programmed cell death, distinguished from apoptosis, autophagy, and programmed necrosis and has received much attention since it was defined in 2012. Ferroptotic cells physiologically exhibit iron metabolism dysregulation, oxidative stress, and lipid peroxidation. Morphologically, they show plasma membrane disruption, cytoplasmic swelling, and mitochondrial condensation. Osteoporosis is taken more and more seriously as the proportion of the aging population continues to increase globally. Interestingly, ferroptosis has been demonstrated to be involved in the development and progression of osteoporosis in many extant studies. The review summarizes iron metabolism, lipid peroxidation, and the different regulatory signals in ferroptosis. Changes in signaling mechanisms within osteoblasts, osteoclasts, and osteocytes after ferroptosis occur are explained here. Studies showed ferroptosis play an important role in different osteoporosis models (diabetes osteoporosis, postmenopausal osteoporosis, glucocorticoid-induced osteoporosis). Inhibitors and EC (Exos) targeting ferroptosis could ameliorate bone loss in osteoporotic mice by protecting cells against lipid peroxidation. Shortly, we hope that more effective and appropriate clinical therapy means will be utilized in the treatment of osteoporosis.

Interference with ENO2 promotes ferroptosis and inhibits glycolysis in clear cell renal cell carcinoma by regulating Hippo­YAP1 signaling.

Glycolytic enzyme enolase 2 (ENO2) is dysregulated in various cancer types. Nevertheless, the role and underlying mechanism of ENO2 in clear cell renal cell carcinoma (ccRCC) remain unclear. Therefore, the current study investigated the effect and mechanism of ENO2 in ccRCC. ENO2 expression in a ccRCC cell line was assessed using reverse transcription-quantitative PCR and western blotting. Analysis of glycolysis was performed by estimating the extracellular acidification rate, lactic acid concentration, glucose uptake and the expression of glucose transporter 1, pyruvate kinase muscle isozyme M2 and hexokinase 2. Moreover, ferroptosis was assessed by detecting the level of total iron, lipid peroxide, reactive oxygen species and the expression of ferroptosis-related protein. In addition, mitochondrial function was assessed using JC-1 staining and detection kits. The results indicated that ENO2 is expressed at high levels in ccRCC cell lines, and interference with ENO2 expression inhibits glycolysis, promotes ferroptosis and affects mitochondrial function in ccRCC cells. Further investigation demonstrated that interference with ENO2 expression affected ferroptosis levels in ccRCC cells by inhibiting the glycolysis process. Mechanistically, the present results indicated that ENO2 may affect ferroptosis, glycolysis and mitochondrial functions by regulating Hippo-yes-associated protein 1 (YAP1) signaling in ccRCC cells. In conclusion, the present study showed that ENO2 affects ferroptosis, glycolysis and mitochondrial functions in ccRCC cells by regulating Hippo-YAP1 signaling, hence demonstrating its potential as a therapeutic target in ccRCC.

Deciphering the role of ferroptosis in rheumatoid arthritis: Synovial transcriptome analysis and immune infiltration correlation.

The pathogenesis of rheumatoid arthritis (RA) remains elusive. The initiation of joint degeneration is characterized by the loss of self-tolerance in peripheral joints. Ferroptosis, a form of regulated cell death, holds significant importance in the pathophysiology of inflammatory arthritis, primarily due to iron accumulation and the subsequent lipid peroxidation. The present study investigated the association between synovial lesions and ferroptosis-related genes using previously published data from rheumatoid patients. Transcriptome differential gene analysis was employed to identify ferroptosis-related differentially expressed genes (FRDEGs). To validate FRDEGs and screen hub genes, we used weighted gene co-expression network analysis (WGCNA) and receiver operating characteristic (ROC) curves. Subsequently, immune infiltration analysis and single cell analysis were conducted to investigate the relationship between various synovial tissues cells and FRDEGs. The findings were further confirmed through reverse transcription-quantitative polymerase chain reaction (RT-qPCR), immunohistochemical staining, and immunofluorescence techniques. Upon intersecting DEGs with ferroptosis-related genes, we identified a total of 104 FRDEGs. Through the construction of a protein-protein interaction (PPI) network, we pinpointed the top 20 most highly concentrated genes as hub genes. Subsequent analyses using ROC curve and WGCNA validated eight FRDEGs: TIMP1, JUN, EGFR, SREBF1, ADIPOQ, SCD, AR, and FABP4. Immuno-infiltration analyses revealed significant infiltration of immune cell in RA synovial tissues and their correlations with the FRDEGs. Notably, TIMP1 demonstrated a positive correlation with various immune cell populations. Single-cell sequencing date of RA synovial tissue revealed predominant expression of TIMP1 is in fibroblasts. RT-qPCR, immunohistochemistry, and immunofluorescence analyses confirmed significant upregulation of TIMP1 at both mRNA and protein levels in RA synovial tissues and fibroblast-like synoviocytes (FLS). The findings provide novel insights into pathophysiology of peripheral immune tolerance deficiency in RA. The dysregulation of TIMP1, a gene associated with ferroptosis, was significantly observed in RA patients, suggesting its potential as a promising biomarker and therapeutic target.

Nutrient vitamins enabled metabolic regulation of ferroptosis via reactive oxygen species biology.

Vitamins are dietary components necessary for cellular metabolic balance, especially redox homeostasis; deficient or excessive supply may give rise to symptoms of psychiatric disorders. Exploring the nutritional and metabolic pathways of vitamins could contribute to uncovering the underlying pathogenesis of ferroptosis-associated diseases. This mini-review aims to provide insights into vitamins closely linked to the regulation of ferroptosis from the perspective of cellular reactive oxygen species biology. The mainstream reprogramming mechanisms of ferroptosis are overviewed, focusing on unique biological processes of iron metabolism, lipid metabolism, and amino acid metabolism. Moreover, recent breakthroughs in therapeutic interventions targeting ferroptosis via fully utilizing vitamin-based pharmacological tools were overviewed, covering vitamins (B, C, E, and K). Finally, mechanism insight related to vitamin-associated nutrient signaling was provided, highlighting the pharmacological benefits of metabolically reprogramming ferroptosis-associated diseases.

Design, synthesis, and biological evaluation of RSL3-based GPX4 degraders with hydrophobic tags.

Ferroptosis is a new type of programmed cell death characterized by iron-dependent lipid peroxidation, during which glutathione peroxidase 4 (GPX4) plays an essential role and is well-recognized as a promising therapeutic target for cancer treatment. Although some GPX4 degradation molecules have been developed to induce ferroptosis, the discovery of GPX4 degraders with hydrophobic tagging (HyT) as an innovative approach is more challenging. Herein, we designed and synthesized a series of HyT degraders by linking the GPX4 inhibitor RSL3 with a hydrophobic and bulky group of adamantane. Among them, compound R8 is a potent degrader (DC50, 24h = 0.019 µM) which can effectively degrade GPX4 in a dose- and time-dependent manner. Furthermore, compound R8 exhibited superior in vitro antitumor potency against HT1080 and MDA-MB-231 cell lines with IC50 values of 24 nM and 32 nM respectively, which are 4 times more potent than parental compound RSL3. Mechanistic investigation evidenced that R8 consumes GPX4 protein mainly through the ubiquitin proteasome (UPS) and enables to induce the accumulation of LPO, thereby triggering ferroptosis. Our work presented the novel GPX4 degrader of R8 by HyT strategy, and provided a promising pathway of degradation agents for the treatment of ferroptosis relevant diseases.

CREG1 attenuates doxorubicin-induced cardiotoxicity by inhibiting the ferroptosis of cardiomyocytes.

OBJECTIVE: Doxorubicin (DOX)-induced cardiotoxicity limits the application of DOX in cancer patients. Currently, there is no effective prevention or treatment for DOX-induced cardiotoxicity. The cellular repressor of E1A-stimulated genes (CREG1) is a cardioprotective factor that plays an important role in the maintenance of cardiomyocytes differentiation and homeostasis. However, the role and mechanism of CREG1 in DOX-induced cardiotoxicity has not yet been elucidated. METHODS: In vivo, C57BL/6J mice, CREG1 transgenic and cardiac-specific CREG1 knockout mice were used to establish a DOX-induced cardiotoxicity model. H&E staining, Masson's trichrome, WGA staining, real-time PCR, and western blotting were performed to examine fibrosis and ferroptosis in the myocardium. In vitro, neonatal mouse cardiomyocytes (NMCMs) were cultured and stimulated with DOX, CREG1-overexpressed adenovirus, and small interfering RNA was used to establish CREG1 overexpression or knockdown cardiomyocytes. Transcriptomics, real-time PCR, western blotting, and immunoprecipitation were used to examine the roles and mechanisms of CREG1 in cardiomyocytes ferroptosis. RESULTS: The mRNA and protein levels of CREG1 were reduced in the hearts and NMCMs after DOX treatment. CREG1 overexpression alleviated myocardial damage and inhibited DOX-induced ferroptosis in the myocardium. CREG1 deficiency in the heart aggravated DOX-induced cardiotoxicity and ferroptosis. In vitro, CREG1 overexpression inhibited cardiomyocytes ferroptosis induced by DOX, and CREG1 knockdown aggravated DOX-induced cardiotoxicity. Mechanistically, CREG1 inhibited the mRNA and protein expression of pyruvate dehydrogenase kinase 4 (PDK4) by regulating the F-box and WD repeat domain containing 7 (FBXW7)-forkhead box O1 (FOXO1) pathway. PDK4 deficiency reversed the effects of CREG1 knockdown on cardiomyocytes ferroptosis following DOX treatment. CONCLUSION: CREG1 alleviated DOX-induced cardiotoxicity by inhibiting ferroptosis in cardiomyocytes. Our findings may help clarify the new roles of CREG1 in the development of DOX-induced cardiotoxicity.

In vivo vulnerabilities to GPX4 and HDAC inhibitors in drug-persistent versus drug-resistant BRAFV600E lung adenocarcinoma.

The current targeted therapy for BRAFV600E-mutant lung cancer consists of a dual blockade of RAF/MEK kinases often combining dabrafenib/trametinib (D/T). This regimen extends survival when compared to single-agent treatments, but disease progression is unavoidable. By using whole-genome CRISPR screening and RNA sequencing, we characterize the vulnerabilities of both persister and D/T-resistant cellular models. Oxidative stress together with concomitant induction of antioxidant responses is boosted by D/T treatment. However, the nature of the oxidative damage, the choice of redox detoxification systems, and the resulting therapeutic vulnerabilities display stage-specific differences. Persister cells suffer from lipid peroxidation and are sensitive to ferroptosis upon GPX4 inhibition in vivo. Biomarkers of lipid peroxidation are detected in clinical samples following D/T treatment. Acquired alterations leading to mitogen-activated protein kinase (MAPK) reactivation enhance cystine transport to boost GPX4-independent antioxidant responses. Similarly to BRAFV600E-mutant melanoma, histone deacetylase (HDAC) inhibitors decrease D/T-resistant cell viability and extend therapeutic response in vivo.

1,25-D3 ameliorates ischemic brain injury by alleviating endoplasmic reticulum stress and ferroptosis: Involvement of vitamin D receptor and p53 signaling.

Endoplasmic reticulum stress (ERS) and ferroptosis are linked to cerebral ischemia reperfusion injury (CIRI). The neuroprotective properties of 1α, 25-dihydroxyvitamin D3 (VitD3 or 1,25-D3) have been well established; however, the mechanism by which VitD3 treats CIRI through ERS and ferroptosis has not been examined. Hence, we developed middle cerebral artery occlusion/reperfusion (MCAO/R) model in SD rats to ascertain if VitD3 preconditioning mediates ERS and ferroptosis involving of p53 signaling. In this study, we observed that VitD3 can reduce infarction volume and cerebral edema, which leads to the improvement of nerve function. HE, Nissl and Tunel staining showed that VitD3 treatment significantly improved the morphology of neuronal cells and reduced their death. The expression and activation of Vitamin D receptor (VDR), PKR-like ER kinase (PERK), C/EBP-homologous protein (CHOP), p53, nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4) and reactive oxygen species (ROS) in the ischemic penumbral area were detected by real-time qPCR, Western-blotting and Elisa. The results showed that after VitD3 treatment, VDR increased, ERS-related indices (PERK, CHOP) significantly decreased and ferroptosis-related indices (Nrf2, GPX4) increased. As a VDRs antagonist, pyridoxal-5-phosphate (P5P) can partially block the neuroprotective effects of VitD3. Therefore, CIRI can induce ERS and ferroptosis in the ischemic penumbra area and VitD3 may ameliorate nerve damage in CIRI rats by up-regulating VDR, alleviating p53-associated ERS and ferroptosis.

Hypoxia and ferroptosis.

Ferroptosis is a novel, iron-dependent cell death characterized by the excessive accumulation of ferroptosis lipid peroxides ultimately leading to oxidative damage to the cell membrane. Iron, lipid, amino acid metabolism, and other signaling pathways all control ferroptosis. Numerous bodily tissues experience hypoxia under normal and pathological circumstances. Tissue cells can adjust to these changes by activating the hypoxia-inducible factor (HIF) signaling pathway and other mechanisms in response to the hypoxic environment. In recent years, there has been increasing evidence that hypoxia and ferroptosis are closely linked, and that hypoxia can regulate ferroptosis in specific cells and conditions through different pathways. In this paper, we review the possible positive and negative regulatory mechanisms of ferroptosis by hypoxia-inducible factors, as well as ferroptosis-associated ischemic diseases, with the intention of delivering novel therapeutic avenues for the defense and management of hypoxic illnesses linked to ferroptosis.

Dyslipidemia-induced renal fibrosis related to ferroptosis and endoplasmic reticulum stress.

Dyslipidemia may induce chronic kidney disease and trigger both ferroptosis and endoplasmic reticulum (ER) stress, but the instigating factors are incompletely understood. We tested the hypothesis that different models of dyslipidemia engage distinct kidney injury mechanisms. Wild-type (WT) or proprotein-convertase subtilisin/kexin type-9 (PCSK9)-gain-of-function (GOF) Ossabaw pigs were fed with a 6-months normal (ND) or high-fat (HFD) diet (n=5-6 each). Renal function and fat deposition were studied in-vivo using CT, and blood and kidney tissue studied ex-vivo for lipid profile, systemic and renal vein free fatty acids (FFA) levels, and renal injury mechanisms including lipid peroxidation (LPO), ferroptosis, and ER stress. Compared with WT-ND pigs, both HFD and PCSK9-GOF elevated triglyceride levels, which were highest in WT-HFD, whereas total and low-density lipoprotein (LDL) cholesterol levels rose only in PCSK9-GOF pigs, particularly in PCSK9-GOF/HFD. The HFD groups had worse kidney function than ND. The WT-HFD kidneys retained more FFA than other groups, but all kidneys developed fibrosis. Furthermore, HFD-induced ferroptosis in WT-HFD indicated by increased free iron, and LPO, and decreased glutathione peroxidase-4 mRNA expression, while PCSK9-GOF induced ER stress with upregulated GRP94 and CHOP protein expression. In vitro, PK1 cells treated with palmitic acid (PA) and oxidized-LDL to mimic HFD and PCSK9-GOF showed similar trends to those observed in vivo. Taken together, HFD-induced hypertriglyceridemia promotes renal FFA retention and ferroptosis, whereas PCSK9-GOF-induced hypercholesterolemia elicits ER stress, both resulting in renal fibrosis. These observations suggest different targets for preventing and treating renal fibrosis in subjects with specific types of dyslipidemia.

Preliminary evidence for the presence of programmed cell death in pressure injuries.

Pressure injuries (PIs) are a common healthcare problem worldwide and are considered to be the most expensive chronic wounds after arterial ulcers. Although the gross factors including ischemia-reperfusion (I/R) have been identified in the etiology of PIs, the precise cellular and molecular mechanisms contributing to PIs development remain unclear. Various forms of programmed cell death including apoptosis, autophagy, pyroptosis, necroptosis and ferroptosis have been identified in PIs. In this paper, we present a detailed overview on various forms of cell death; discuss the recent advances in the roles of cell death in the occurrence and development of PIs and found much of the evidence is novel and based on animal experiments. Herein, we also state critical evaluation of the existing data and future perspective in the field. A better understanding of the programmed cell death mechanism in PIs may have important implications in driving the development of new preventive and therapeutic strategies.