Selenium inhibits ferroptosis and ameliorates autistic-like behaviors of BTBR mice by regulating the Nrf2/GPx4 pathway

Selenium maintains intestinal epithelial cells to activate M2 macrophages against deoxynivalenol injury

Selenium (Se) is indispensable in alleviating various types of intestinal injuries. Here, we thoroughly investigated the protective effect of Se on the regulation of the epithelial cell-M2 macrophages pathway in deoxynivalenol (DON)-induced intestinal damage. In the present study, Se has positive impacts on gut health by improving gut barrier function and reducing the levels of serum DON in vivo. Furthermore, our study revealed that Se supplementation increased the abundances of GPX4, p-PI3K, and AKT, decreased the levels of 4-HNE and inhibited ferroptosis. Moreover, when mice were treated with DON and Fer-1(ferroptosis inhibitor), ferroptosis was suppressed and PI3K/AKT pathway was activated. These results indicated that GPX4-PI3K/AKT-ferroptosis was a predominant pathway in DON-induced intestinal inflammation. Interestingly, we discovered that both the number of M2 anti-inflammatory macrophages and the levels of CSF-1 decreased while the pro-inflammatory cytokine IL-6 increased in the intestine and MODE-K cells supernatant. Therefore, Se supplementation activated the CSF-1-M2 macrophages axis, resulting in a decrease in IL-6 expression and an enhancement of the intestinal anti-inflammatory capacity. This study provides novel insights into how intestinal epithelial cells regulate the CSF-1-M2 macrophage pathway, which is essential in maintaining intestinal homeostasis confer to environmental hazardous stimuli.

Ferroptosis in ulcerative colitis: Potential mechanisms and promising therapeutic targets

Ulcerative colitis (UC) is a complex immune-mediated chronic inflammatory bowel disease. It is mainly characterized by diffuse inflammation of the colonic and rectal mucosa with barrier function impairment. Identifying new biomarkers for the development of more effective UC therapies remains a pressing task for current research. Ferroptosis is a newly identified form of regulated cell death characterized by iron-dependent lipid peroxidation. As research deepens, ferroptosis has been demonstrated to be involved in the pathological processes of numerous diseases. A growing body of evidence suggests that the pathogenesis of UC is associated with ferroptosis, and the regulation of ferroptosis provides new opportunities for UC treatment. However, the specific mechanisms by which ferroptosis participates in the development of UC remain to be more fully and thoroughly investigated. Therefore, in this review, we focus on the research advances in the mechanism of ferroptosis in recent years and describe the potential role of ferroptosis in the pathogenesis of UC. In addition, we explore the underlying role of the crosslinked pathway between ferroptosis and other mechanisms such as macrophages, neutrophils, autophagy, endoplasmic reticulum stress, and gut microbiota in UC. Finally, we also summarize the potential compounds that may act as ferroptosis inhibitors in UC in the future.

Central Causation of Autism/ASDs via Excessive [Ca2+]i Impacting Six Mechanisms Controlling Synaptogenesis during the Perinatal Period: The Role of Electromagnetic Fields and Chemicals and the NO/ONOO(-) Cycle, as Well as Specific Mutations

The roles of perinatal development, intracellular calcium [Ca2+]i, and synaptogenesis disruption are not novel in the autism/ASD literature. The focus on six mechanisms controlling synaptogenesis, each regulated by [Ca2+]i, and each aberrant in ASDs is novel. The model presented here predicts that autism epidemic causation involves central roles of both electromagnetic fields (EMFs) and chemicals. EMFs act via voltage-gated calcium channel (VGCC) activation and [Ca2+]i elevation. A total of 15 autism-implicated chemical classes each act to produce [Ca2+]i elevation, 12 acting via NMDA receptor activation, and three acting via other mechanisms. The chronic nature of ASDs is explained via NO/ONOO(-) vicious cycle elevation and MeCP2 epigenetic dysfunction. Genetic causation often also involves [Ca2+]i elevation or other impacts on synaptogenesis. The literature examining each of these steps is systematically examined and found to be consistent with predictions. Approaches that may be sed for ASD prevention or treatment are discussed in connection with this special issue: The current situation and prospects for children with ASDs. Such approaches include EMF, chemical avoidance, and using nutrients and other agents to raise the levels of Nrf2. An enriched environment, vitamin D, magnesium, and omega-3s in fish oil may also be helpful.

Ligustilide inhibits Purkinje cell ferritinophagy via the ULK1/NCOA4 pathway to attenuate valproic acid-induced autistic features

BACKGROUND

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder in which social impairment is the core symptom. Presently, there are no definitive medications to cure core symptoms of ASD, and most therapeutic strategies ameliorate ASD symptoms. Treatments with proven efficacy in autism are imminent. Ligustilide (LIG), an herbal monomer extracted from Angelica Sinensis and Chuanxiong, is mainly distributed in the cerebellum and widely used in treating neurological disorders. However, there are no studies on its effect on autistic-like phenotypes and its mechanism of action.

PURPOSE

Investigate the efficacy and mechanism of LIG in treating ASD using two Valproic acid(VPA)-exposed and BTBR T + Itpr3tf/J (BTBR) mouse models of autism.

METHODS

VPA-exposed mice and BTBR mice were given LIG for treatment, and its effect on autistic-like phenotype was detected by behavioral experiments, which included a three-chamber social test. Subsequently, RNA-Sequence(RNA-Seq) of the cerebellum was performed to observe the biological changes to search target pathways. The autophagy and ferroptosis pathways screened were verified by WB(Western Blot) assay, and the cerebellum was stained by immunofluorescence and examined by electron microscopy. To further explore the therapeutic mechanism, ULK1 agonist BL-918 was used to block the therapeutic effect of LIG to verify its target effect.

RESULTS

Our work demonstrates that LIG administration from P12-P14 improved autism-related behaviors and motor dysfunction in VPA-exposed mice. Similarly, BTBR mice showed the same improvement. RNA-Seq data identified ULK1 as the target of LIG in regulating ferritinophagy in the cerebellum of VPA-exposed mice, as evidenced by activated autophagy, increased ferritin degradation, iron overload, and lipid peroxidation. We found that VPA exposure-induced ferritinophagy occurred in the Purkinje cells, with enhanced NCOA4 and Lc3B expressions. Notably, the therapeutic effect of LIG disappeared when ULK1 was activated.

CONCLUSION

LIG treatment inhibits ferritinophagy in Purkinje cells via the ULK1/NCOA4-dependent pathway. Our study reveals for the first time that LIG treatment ameliorates autism symptoms in VPA-exposed mice by reducing aberrant Purkinje ferritinophagy. At the same time, our study complements the pathogenic mechanisms of autism and introduces new possibilities for its therapeutic options.

Interaction of prenatal maternal selenium and manganese levels on child neurodevelopmental trajectories-the Shanghai birth cohort study

OBJECTIVE

The fetal brain is particularly plastic, and may be concurrently affected by chemical exposure and malnutritional factors. Selenium is essential for the developing brain, and excess manganese exposure may exert neurotoxic effects. However, few epidemiological studies have evaluated the interaction of manganese and selenium assessed in different prenatal stages on postnatal neurodevelopmental trajectories.

METHODS

This study contained 1024 mother-child pairs in the Shanghai-birth-cohort study from 2013 to 2016 recruited since early/before pregnancy with complete data on manganese and selenium levels in different prenatal stages and infant neurodevelopmental trajectories. Whole blood manganese and selenium in early pregnancy and around birth were measured by inductively-coupled-plasma-mass-spectrometry (ICP-MS), children's cognitive development was evaluated at 6, 12, and 24 months of age using Age & Stage-Questionnaire (ASQ)-3 and Bayley-III. Multiple linear regression was used to investigate the interaction of prenatal selenium and manganese on neurodevelopmental trajectories.

RESULTS

The prenatal manganese and selenium levels were 1.82 ± 0.98 μg/dL and 13.53 ± 2.70 μg/dL for maternal blood in early pregnancy, and 5.06 ± 1.67 μg/dL and 11.81 ± 3.35 μg/dL for umbilical cord blood, respectively. Higher prenatal Se levels were associated with better neurocognitive performances or the consistently-high-level trajectory (P < 0.05), with more significant associations observed in early pregnancy than around birth. However, such positive relationships became non-significant or even adverse in high (vs. low) manganese status, and the effect differences between low and high manganese were more significant in early pregnancy.

CONCLUSIONS

Prenatal Selenium was positively associated with child neurodevelopment, but prenatal high manganese may mitigate such favorable effects. The effects were mainly observed in earlier prenatal stage.

Selenomethionine alleviates decabromodiphenyl ether-induced oxidative stress and ferroptosis via the NRF2/GPX4 pathway in the chicken brain

Decabromodiphenyl ether (BDE209) is a toxic environmental pollutant that can cause neurotoxicity, behavioral abnormalities, and cognitive impairment in animals. However, the specific mechanisms of BDE209-induced neurological injury and effective preventative and therapeutic interventions are lacking. Even though selenomethionine (Se-Met) has a significant detoxification effect and protects the nervous system, it remains unclear whether Se-Met can counteract the toxic effects of BDE209. For the in vivo test, we randomly divided 60 1-week-old hy-line white variety chicks into the Con, BDE209, Se-Met, and BDE209 +Se-Met groups. In vitro experiments were performed, exposing chick embryo brain neurons to BDE209, Se-Met, N-Acetylcysteine (NAC, a ROS inhibitor), and RSL3 (a GPX4 inhibitor). We demonstrated that BDE209 induced oxidative stress and ferroptosis in the chicken brain, which mainly manifested as mitochondrial atrophy, cristae breakage, increased Fe2+ and MDA content, decreased antioxidant enzyme activity, and the inhibition of the NRF2/GPX4 signaling pathway in the brain neurons. However, Se-Met supplementation reversed these changes by activating the NRF2/GPX4 pathway, reducing mitochondrial damage, enhancing antioxidant enzyme activity, and alleviating ferroptosis. This study provides insight into the mechanism of BDE209-related neurotoxicity and suggests Se-Met as an effective preventative and control measure against BDE209 poisoning.

Sodium aescinate induces renal toxicity by promoting Nrf2/GPX4-mediated ferroptosis

Sodium aescinate (SA) is extracted from Aesculus wilsonii Rehd seeds and was first marketed as a medicament in German. With the wide application of SA in clinical practice, reports of adverse drug reactions and adverse events have gradually increased, including renal impairment. However, the pathogenic mechanisms of SA have not yet been fully elucidated. The toxic effects and underlying mechanisms of SA were explored in this study. Our data showed that SA significantly elevated the levels of blood urea nitrogen (BUN), serum creatinine (Scr) and Kidney injury molecule 1 (Kim-1), accompanied by pathologically significant changes in renal tissue. SA induced NRK-52E cell death and disrupted the integrity of the cell membrane. Moreover, SA caused significant reductions in FTH, Nrf2, xCT, GPX4, and FSP1 levels, but increased TFR1 and ACSL4 levels. SA decreased glutathione peroxidase (GPx), glutathione (GSH) and cysteine (Cys) levels, but improved Fe2+, malondialdehyde (MDA), reactive oxygen species (ROS) and lipid peroxidation levels, ultimately leading to the induction of ferroptosis. Importantly, inhibition of ferroptosis or activation of the Nrf2/GPX4 pathway prevented SA-induced nephrotoxicity. These findings indicated that SA induced oxidative damage and ferroptosis-mediated kidney injury by suppressing the Nrf2/GPX4 axis activity.

Ferroptosis and its emerging role in kidney stone formation

Kidney stone is a common and highly recurrent disease in urology, and its pathogenesis is associated with various factors. However, its precise pathogenesis is still unknown. Ferroptosis describes a form of regulated cell death that is driven by unrestricted lipid peroxidation, which does not require the activation of caspase and can be suppressed by iron chelators, lipophilic antioxidants, inhibitors of lipid peroxidation, and depletion of polyunsaturated fatty acids. Recent studies have shown that ferroptosis plays a crucial role in kidney stone formation. An increasing number of studies have shown that calcium oxalate, urate, phosphate, and selenium deficiency induce ferroptosis and promote kidney stone formation through mechanisms such as oxidative stress, endoplasmic reticulum stress, and autophagy. We also offered a new direction for the downstream mechanism of ferroptosis in kidney stone formation based on the "death wave" phenomenon. We reviewed the emerging role of ferroptosis in kidney stone formation and provided new ideas for the future treatment and prevention of kidney stones.

Puerarin attenuates valproate-induced features of ASD in male mice via regulating Slc7a11-dependent ferroptosis

Autism spectrum disorder (ASD) is a complicated, neurodevelopmental disorder characterized by social deficits and stereotyped behaviors. Accumulating evidence suggests that ferroptosis is involved in the development of ASD, but the underlying mechanism remains elusive. Puerarin has an anti-ferroptosis function. Here, we found that the administration of puerarin from P12 to P15 ameliorated the autism-associated behaviors in the VPA-exposed male mouse model of autism by inhibiting ferroptosis in neural stem cells of the hippocampus. We highlight the role of ferroptosis in the hippocampus neurogenesis and confirm that puerarin treatment inhibited iron overload, lipid peroxidation accumulation, and mitochondrial dysfunction, as well as enhanced the expression of ferroptosis inhibitory proteins, including Nrf2, GPX4, Slc7a11, and FTH1 in the hippocampus of VPA mouse model of autism. In addition, we confirmed that inhibition of xCT/Slc7a11-mediated ferroptosis occurring in the hippocampus is closely related to puerarin-exerted therapeutic effects. In conclusion, our study suggests that puerarin targets core symptoms and hippocampal neurogenesis reduction through ferroptosis inhibition, which might be a potential drug for autism intervention.

Hepatic Alterations in a BTBR T + Itpr3tf/J Mouse Model of Autism and Improvement Using Melatonin via Mitigation Oxidative Stress, Inflammation and Ferroptosis

Autism spectrum disorder (ASD) is a complicated neurodevelopmental disorder, and its etiology is not well understood. It is known that genetic and nongenetic factors determine alterations in several organs, such as the liver, in individuals with this disorder. The aims of the present study were to analyze morphological and biological alterations in the liver of an autistic mouse model, BTBR T + Itpr3tf/J (BTBR) mice, and to identify therapeutic strategies for alleviating hepatic impairments using melatonin administration. We studied hepatic cytoarchitecture, oxidative stress, inflammation and ferroptosis in BTBR mice and used C57BL6/J mice as healthy control subjects. The mice were divided into four groups and then treated and not treated with melatonin, respectively. BTBR mice showed (a) a retarded development of livers and (b) iron accumulation and elevated oxidative stress and inflammation. We demonstrated that the expression of ferroptosis markers, the transcription factor nuclear factor erythroid-related factor 2 (NFR2), was upregulated, and the Kelch-like ECH-associated protein 1 (KEAP1) was downregulated in BTBR mice. Then, we evaluated the effects of melatonin on the hepatic alterations of BTBR mice; melatonin has a positive effect on liver cytoarchitecture and metabolic functions.

Ferroptosis: a new antidepressant pharmacological mechanism

The incidence rate of depression, a mental disorder, is steadily increasing and has the potential to become a major global disability factor. Given the complex pathological mechanisms involved in depression, the use of conventional antidepressants may lead to severe complications due to their side effects. Hence, there is a critical need to explore the development of novel antidepressants. Ferroptosis, a newly recognized form of cell death, has been found to be closely linked to the onset of depression. Several studies have indicated that certain active ingredients can ameliorate depression by modulating the ferroptosis signaling pathway. Notably, traditional Chinese medicine (TCM) active ingredients and TCM prescriptions have demonstrated promising antidepressant effects in previous investigations owing to their unique advantages in antidepressant therapy. Building upon these findings, our objective was to review recent relevant research and provide new insights and directions for the development and application of innovative antidepressant strategies.

Advances on the Role of Ferroptosis in Ionizing Radiation Response

Ferroptosis is an iron-dependent programmed cell death mode that is distinct from other cell death modes, and radiation is able to stimulate cellular oxidative stress and induce the production of large amounts of reactive oxygen radicals, which in turn leads to the accumulation of lipid peroxide and the onset of ferroptosis. In this review, from the perspective of the role of ferroptosis in generating a radiation response following cellular irradiation, the relationship between ferroptosis induced by ionizing radiation stress and the response to ionizing radiation is reviewed, including the roles of MAPK and Nrf2 signaling pathways in ferroptosis, resulting from the oxidative stress response to ionizing radiation, the metabolic regulatory role of the p53 gene in ferroptosis, and regulatory modes of action of iron metabolism and iron metabolism-related regulatory proteins in promoting and inhibiting ferroptosis. It provides some ideas for the follow-up research to explore the specific mechanism and regulatory network of ferroptosis in response to ionizing radiation.

Grape seed-derived procyanidin inhibits glyphosate-induced hepatocyte ferroptosis via enhancing crosstalk between Nrf2 and FGF12

BACKGROUND

Glyphosate (GLY) exposure induces hepatocyte ferroptosis through overproduction of reactive oxygen species, regarded as an important contributor to liver damage. Grape seed-derived procyanidin (GSDP) has been reported to be an effective antioxidant, but whether and, if any, how GSDP can attenuate GLY-induced liver injury via inhibiting ferroptosis is unclear.

PURPOSE

The current study aimed to investigate the hepato-protective effects and possible mechanisms of GSDP.

METHODS

GLY-induced liver damage mice model was established to explore the hepatoprotective roles of GSPE in vivo. Subsequently, bioinformatics methodology was used to predict the key pathways and factors related to the action targets of GSPE against hepatocyte ferroptosis. Finally, we explored the roles of nuclear factor E2 related factor 2 (Nrf2) and fibroblast growth factor 21 (FGF21) in blunting GLY-induced liver damage via suppressing ferroptosis in vitro.

RESULTS

GSDP exerts hepato-protective effects in vivo and in vitro through reduced oxidative stress and inhibited ferroptosis, which was related to the activation of Nrf2. Bioinformatics analysis showed an interaction between Nrf2 and FGF21. Furthermore, Nrf2 inhibition reduced FGF21 expression in the mRNA and protein levels. Fgf21 knockdown suppressed Nrf2 expression level, but recombinant FGF21 protein increased Nrf2 expression and promoted Nrf2 translocation into nucleus, suggesting a crosstalk between Nrf2 and FGF21. Intriguingly, the decreased levels of Nrf2 and FGF21 compromised the protective roles of GSDP against GLY-induced hepatocyte ferroptosis.

CONCLUSION

These findings suggest that GSDP attenuates GLY-caused hepatocyte ferroptosis via enhancing the interplay between Nrf2 and FGF21. Thus, GSDP may be a promising natural compound to antagonize ferroptosis-related damage.

Sodium selenite (Na2SeO3) attenuates T-2 toxin-induced iron death in LMH cells through the ROS/PI3K/AKT/Nrf2 pathway

T-2 toxin, is a monotrichous mycotoxin commonly found in animal feed and agricultural products that can damage tissues and organs through oxidative stress. Selenium is a trace element with favorable antioxidant effects. However, it is unclear whether T-2 toxin-induces ferroptosis in LMH cells and whether Na2SeO3 has a protective role in this process. To investigate the process of hepatic injury by T-2 toxin and its antagonistic effect by Na2SeO3, we used 20 ng/mL T-2 toxin as well as 160 nmol/L Na2SeO3 to treat the LMH cells. The results demonstrated that exposure to the T-2 toxin induced iron death by increasing the quantity of ROS, leading to oxidative damage, decreasing the quantities of SOD, GPx, and T-AOC, and increasing the accumulation of MDA and H2O2, which resulted in the accumulation of Fe2+ and the down-regulation of the manifestation of linked genes and proteins including FTH1, Gpx4, NQO-1, and HO-1. After the addition of Na2SeO3, the PI3K/AKT/Nrf2 pathway is activated by regulating the selenoproteins gene level, and the above abnormal changes are reversed. In summary, Na2SeO3 alleviated T-2 toxin-induced iron death via the PI3K/AKT/Nrf2 pathway. These study not only broaden the cytotoxic knowledge regarding T-2 toxin, but also serve as a foundation for the use of Na2SeO3 in daily life.

Biogenic Selenium Nanoparticles Synthesized Using Alginate Oligosaccharides Attenuate Heat Stress-Induced Impairment of Breast Meat Quality via Regulating Oxidative Stress, Metabolome and Ferroptosis in Broilers

Selenium (Se) is an indispensable trace element with versatile functions in antioxidant defense in poultry. In our previous study, we synthesized a novel type of biogenic selenium nanoparticle based on alginate oligosaccharides (SeNPs-AOS), and found that the particles are sized around 80 nm with an 8% Se content, and the dietary addition of 5 mg/kg of SeNPs-AOS could effectively alleviate the deleterious effects of heat stress (HS) in broilers, but it is still unclear whether SeNPs-AOS can improve the meat quality. Therefore, the aim of this study was to evaluate the protective effects of SeNPs-AOS on breast meat quality in heat-stressed broilers, and explore the relevant mechanisms. Birds at the age of 21 days were randomly divided into four groups with six replicates per group (eight broilers per replicate) according to a 2 × 2 experimental design, using HS (33 ± 2 °C, 10 h/day vs. thermoneutral, TN, under 23 ± 1.5 °C) and SeNPs-AOS (5 mg/kg feed vs. no inclusion) as variables. The results showed that dietary SeNPs-AOS decreased the cooking loss (p < 0.05), freezing loss (p < 0.001), and shear force (p < 0.01) of breast muscle in heat-stressed broilers. The non-targeted metabolomics analysis of the breast muscle identified 78 differential metabolites between the HS and HS + SeNPs-AOS groups, mainly enriched in the arginine and proline metabolism, β-alanine metabolism, D-arginine and D-ornithine metabolism, pantothenate, and CoA biosynthesis pathways (p < 0.05). Meanwhile, supplementation with SeNPs-AOS increased the levels of the total antioxidant capacity (T-AOC), the activities of catalase (CAT) and glutathione peroxidase (GSH-Px), and decreased the content of malondialdehyde (MDA) in the breast muscle (p < 0.05) in broilers under HS exposure. Additionally, SeNPs-AOS upregulated the mRNA expression of CAT, GPX1, GPX3, heme oxygenase-1 (HO-1), masculoaponeurotic fibrosarcoma G (MafG), MafK, selenoprotein W (SELENOW), SELENOK, ferritin heavy polypeptide-1 (FTH1), Ferroportin 1 (Fpn1), and nuclear factor erythroid 2-related factor 2 (Nrf2) (p < 0.05), while it downregulated Kelch-like ECH-associated pro-36 tein 1 (Keap1) and prostaglandin-endoperoxide Synthase 2 (PTGS2) expression (p < 0.05) in broilers under HS. These findings demonstrated that the dietary addition of SeNPs-AOS mitigated HS-induced oxidative damage and metabolite changes in the breast muscle of broilers, which may be related to the regulation of the Nrf2 signaling pathway and selenoprotein synthesis. In addition, SeNPs-AOS upregulated the breast muscle gene expression of anti-ferroptosis-related molecules in broilers under HS, suggesting that SeNPs-AOS can be used as novel Se supplements against HS in broilers.

Biogenic Selenium Nanoparticles Synthesized with Alginate Oligosaccharides Alleviate Heat Stress-Induced Oxidative Damage to Organs in Broilers through Activating Nrf2-Mediated Anti-Oxidation and Anti-Ferroptosis Pathways

Selenium (Se) is an essential trace element for maintaining health due to its ideal antioxidant properties. We previously prepared a new type of biogenic selenium nanoparticles based on alginate oligosaccharides (SeNPs-AOS), and this study aimed to investigate the protective effects of SeNPs-AOS (Se particle size = 80 nm, Se content = 8%) on organ health in broilers challenged with HS. A total of 192 21-day-old Arbor Acres broilers were randomly divided into four groups according to a 2 × 2 experimental design, including a thermoneutral zone group (TN, raised under 23 ± 1.5 °C); TN + SeNPs-AOS group (TN group supplemented 5 mg/kg SeNPS-AOS); HS group (HS, raised under 33 ± 2 °C for 10 h/day); and HS + SeNPs-AOS group (HS group supplemented 5 mg/kg SeNPS-AOS). There were six replicates in each group (eight broilers per replicate). The results showed that SeNPs-AOS improved the splenic histomorphology, enhanced the activity of catalase (CAT) and glutathione peroxidase (GSH-Px) of the spleen, as well as upregulating the splenic mRNA expression of antioxidant-related genes in broilers under HS. In addition, SeNPs-AOS reversed the pathological changes in bursa caused by HS increased the activity of GST, GSH-Px, and CAT and upregulated the mRNA expression of Nrf2 and antioxidant-related genes in the bursa of heat-stressed broilers. In addition, dietary SeNPs-AOS improved the hepatic damage, increased the activity of GSH-Px in the liver, and upregulated the mRNA expression of antioxidant-related genes while downregulating the Keap1 gene expression of the liver in broilers during HS. Moreover, dietary SeNPs-AOS upregulated the anti-ferroptosis-related genes expression of liver in broilers under HS. In conclusion, dietary SeNPs-AOS could relieve HS-induced oxidative damage to the spleen, bursa of Fabricius and liver in broilers by upregulating the Nrf2-mediated antioxidant gene expression and SeNPs-AOS could also upregulate the expression of hepatic Nrf2-related anti-ferroptosis genes in heat-stressed broilers. These findings are beneficial for the development of new nano-antioxidants in broilers.

Matrine disrupts Nrf2/GPX4 antioxidant system and promotes hepatocyte ferroptosis

Matrine (MT) is an alkaloid isolated from Sophora flavescens with various bioactivities and is widely used clinically. However, the broader its clinical use, the greater its toxicity concerns. We investigate the role of ferroptosis in MT-induced liver injury caused by an imbalance in the antioxidant pathway. Our results showed that MT could cause pathological changes in liver tissues and lead to a significant reduction in L02 cell viability. MT also reduced superoxide dismutase (SOD) and glutathione (GSH), increased malondialdehyde (MDA), reactive oxygen species (ROS), and lipid peroxidation levels, and disrupted iron homeostasis, leading to ferroptosis. In addition, MT decreased the protein levels of FTH, Nrf2, xCT, GPX4, HO-1 and ferroptosis suppressor protein 1 (FSP1) and increased the protein levels of TRF1 and DMT1, characteristic indicators of ferroptosis. Interestingly, the cytotoxic effects of MT were alleviated by ferroptosis inhibitor, Nrf2 agonist, or selenium supplementation. These results revealed that MT triggers hepatocyte ferroptosis by inhibiting the Nrf2/GPX4 antioxidant system.

Selenium inhibits ferroptosis in hyperglycemic cerebral ischemia/reperfusion injury by stimulating the Hippo pathway

Hyperglycemia can exacerbate cerebral ischemia/reperfusion (I/R) injury, and the mechanism involves oxidative stress, apoptosis, autophagy and mitochondrial function. Our previous research showed that selenium (Se) could alleviate this injury. The aim of this study was to examine how selenium alleviates hyperglycemia-mediated exacerbation of cerebral I/R injury by regulating ferroptosis. Middle cerebral artery occlusion (MCAO) and reperfusion models were established in rats under hyperglycemic conditions. An in vitro model of hyperglycemic cerebral I/R injury was created with oxygen-glucose deprivation and reoxygenation (OGD/R) and high glucose was employed. The results showed that hyperglycemia exacerbated cerebral I/R injury, and sodium selenite pretreatment decreased infarct volume, edema and neuronal damage in the cortical penumbra. Moreover, sodium selenite pretreatment increased the survival rate of HT22 cells under OGD/R and high glucose conditions. Pretreatment with sodium selenite reduced the hyperglycemia mediated enhancement of ferroptosis. Furthermore, we observed that pretreatment with sodium selenite increased YAP and TAZ levels in the cytoplasm while decreasing YAP and TAZ levels in the nucleus. The Hippo pathway inhibitor XMU-MP-1 eliminated the inhibitory effect of sodium selenite on ferroptosis. The findings suggest that pretreatment with sodium selenite can regulate ferroptosis by activating the Hippo pathway, and minimize hyperglycemia-mediated exacerbation of cerebral I/R injury.

Exposure to Methylmercury at Juvenile Stage Worsens Autism-like Symptoms in Adult BTBR T+tf/J Mice Due to Lack of Nuclear Factor Erythroid 2-Related Factor 2 Signaling Upregulation in Periphery and Brain

Autism spectrum disorder (ASD) is a multifaceted developmental condition that first appears in infancy. The condition is characterized by recurrent patterns in behavior and impairments in social and vocalization abilities. Methylmercury is a toxic environmental pollutant, and its derivatives are the major source of organic mercury to human beings. Inorganic mercury, which is released from a variety of pollutants into oceans, rivers, and streams, is transformed into methylmercury by bacteria and plankton in the water, which later builds up in fish and shellfish, and then enters humans through the consumption of fish and shellfish and increases the risk of developing ASD by disturbing the oxidant-antioxidant balance. However, there has been no prior research to determine the effect of juvenile exposure of methylmercury chloride on adult BTBR mice. Therefore, the current study evaluated the effect of methylmercury chloride administered during the juvenile stage on autism-like behavior (three-chambered sociability, marble burying, self-grooming tests) and oxidant-antioxidant balance (specifically Nrf2, HO-1, SOD-1, NF-kB, iNOS, MPO, and 3-nitrotyrosine) in the peripheral neutrophils and cortex of adult BTBR and C57BL/6 (B6) mice. Our results show that exposure to methylmercury chloride at a juvenile stage results in autism-like symptoms in adult BTBR mice which are related to a lack of upregulation of the Nrf2 signaling pathway as demonstrated by no significant changes in the expression of Nrf2, HO-1, and SOD-1 in the periphery and cortex. On the other hand, methylmercury chloride administration at a juvenile stage increased oxidative inflammation as depicted by a significant increase in the levels of NF-kB, iNOS, MPO, and 3-nitrotyrosine in the periphery and cortex of adult BTBR mice. This study suggests that juvenile exposure to methylmercury chloride contributes to the worsening of autism-like behavior in adult BTBR mice through the disruption of the oxidant-antioxidant balance in the peripheral compartment and CNS. Strategies that elevate Nrf2 signaling may be useful to counteract toxicant-mediated worsening of ASD and may improve quality of life.

Maturation of nucleus accumbens synaptic transmission signals a critical period for the rescue of social deficits in a mouse model of autism spectrum disorder

Social behavior emerges early in development, a time marked by the onset of neurodevelopmental disorders featuring social deficits, including autism spectrum disorder (ASD). Although social deficits are at the core of the clinical diagnosis of ASD, very little is known about their neural correlates at the time of clinical onset. The nucleus accumbens (NAc), a brain region extensively implicated in social behavior, undergoes synaptic, cellular and molecular alterations in early life, and is particularly affected in ASD mouse models. To explore a link between the maturation of the NAc and neurodevelopmental deficits in social behavior, we compared spontaneous synaptic transmission in NAc shell medium spiny neurons (MSNs) between the highly social C57BL/6J and the idiopathic ASD mouse model BTBR T⁺Itpr3^tf/J at postnatal day (P) 4, P6, P8, P12, P15, P21 and P30. BTBR NAc MSNs display increased spontaneous excitatory transmission during the first postnatal week, and increased inhibition across the first, second and fourth postnatal weeks, suggesting accelerated maturation of excitatory and inhibitory synaptic inputs compared to C57BL/6J mice. BTBR mice also show increased optically evoked medial prefrontal cortex-NAc paired pulse ratios at P15 and P30. These early changes in synaptic transmission are consistent with a potential critical period, which could maximize the efficacy of rescue interventions. To test this, we treated BTBR mice in either early life (P4-P8) or adulthood (P60-P64) with the mTORC1 antagonist rapamycin, a well-established intervention for ASD-like behavior. Rapamycin treatment rescued social interaction deficits in BTBR mice when injected in infancy, but did not affect social interaction in adulthood.

Melatonin reduces radiation-induced ferroptosis in hippocampal neurons by activating the PKM2/NRF2/GPX4 signaling pathway

Ferroptosis is a type of regulated cell death that is dependent on iron and reactive oxygen species (ROS). Melatonin (N-acetyl-5-methoxytryptamine) reduces hypoxic-ischemic brain damage via mechanisms that involve free radical scavenging. How melatonin regulates radiation-induced ferroptosis of hippocampal neurons is yet to be elucidated. In this study, the mouse hippocampal neuronal cell line HT-22 was treated with 20μM melatonin before being stimulated with a combination of irradiation and 100 μM FeCl₃. Furthermore, in vivo experiments were performed in mice treated with melatonin via intraperitoneal injection, which was followed by radiation exposure. A series of functional assays, including CCK-8, DCFH-DA kit, flow cytometry, TUNEL staining, iron estimations, and transmission electron microscopy, were performed on cells as well as hippocampal tissues. The interactions between PKM2 and NRF2 proteins were detected using a coimmunoprecipitation (Co-IP) assay. Moreover, chromatin immunoprecipitation (ChIP), a luciferase reporter assay, and an electrophoretic mobility shift assay (EMSA) were performed to explore the mechanism by which PKM2 regulates the NRF2/GPX4 signaling pathway. The spatial memory of mice was evaluated using the Morris Water Maze test. Hematoxylin-eosin and Nissl staining were performed for histological examination. The results revealed that melatonin protected HT-22 neuronal cells from radiation-induced ferroptosis, as inferred from increased cell viability, decreased ROS production, reduced number of apoptotic cells, and less cristae, higher electron density in mitochondria. In addition, melatonin induced PKM2 nuclear transference, while PKM2 inhibition reversed the effects of melatonin. Further experiments demonstrated that PKM2 bound to and induced the nuclear translocation of NRF2, which regulated GPX4 transcription. Ferroptosis enhanced by PKM2 inhibition was also converted by NRF2 overexpression. In vivo experiments indicated that melatonin alleviated radiation-induced neurological dysfunction and injury in mice. In conclusion, melatonin suppressed ferroptosis to decrease radiation-induced hippocampal neuronal injury by activating the PKM2/NRF2/GPX4 signaling pathway.

Role of ferroptosis in pregnancy related diseases and its therapeutic potential

Ferroptosis is a form of regulated cell death characterized by iron overload, overwhelming lipid peroxidation, and disruption of antioxidant systems. Emerging evidence suggests that ferroptosis is associated with pregnancy related diseases, such as spontaneous abortion, pre-eclampsia, gestational diabetes mellitus, intrahepatic cholestasis of pregnancy, and spontaneous preterm birth. According to these findings, inhibiting ferroptosis might be a potential option to treat pregnancy related diseases. This review summarizes the mechanisms and advances of ferroptosis, the pathogenic role of ferroptosis in pregnancy related diseases and the potential medicines for its treatment.

Propofol Inhibits Ferroptotic Cell Death Through the Nrf2/Gpx4 Signaling Pathway in the Mouse Model of Cerebral Ischemia-Reperfusion Injury

Ferroptosis is characterized by excessive accumulation of iron and lipid peroxides, which are involved in ischemia, reperfusion-induced organ injury, and stroke. Propofol, an anesthetic agent, has neuroprotective effects due to its potent antioxidant, anti-ischemic, and anti-inflammatory properties. However, the relationship between propofol and ferroptosis is still unclear. In the current study, we elucidated the role of ferroptosis in the neuroprotective effect of propofol in mouse brains subjected to cerebral ischemia reperfusion injury (CIRI). Ferroptosis was confirmed by Western blotting assays, transmission electron microscopy, and glutathione assays. Propofol regulated Nrf2/Gpx4 signaling, enhanced antioxidant potential, inhibited the accumulation of lipid peroxides in CIRI-affected neurons, and significantly reversed CIRI-induced ferroptosis. Additionally, Gpx4 inhibitor RSL3 and Nrf2 inhibitor ML385 attenuated the effects of propofol on antioxidant capacity, lipid peroxidation, and ferroptosis in CIRI-affected neurons. Our data support a protective role of propofol against ferroptosis as a cause of cell death in mice with CIRI. Propofol protected against CIRI-induced ferroptosis partly by regulating the Nrf2/Gpx4 signaling pathway. These findings may contribute to the development of future therapies targeting ferroptosis induced by CIRI.

The Rationale for Vitamin, Mineral, and Cofactor Treatment in the Precision Medical Care of Autism Spectrum Disorder

Children with autism spectrum disorder may exhibit nutritional deficiencies due to reduced intake, genetic variants, autoantibodies interfering with vitamin transport, and the accumulation of toxic compounds that consume vitamins. Importantly, vitamins and metal ions are essential for several metabolic pathways and for neurotransmitter functioning. The therapeutic benefits of supplementing vitamins, minerals (Zinc, Magnesium, Molybdenum, and Selenium), and other cofactors (coenzyme Q10, alpha-lipoic acid, and tetrahydrobiopterin) are mediated through their cofactor as well as non-cofactor functions. Interestingly, some vitamins can be safely administered at levels far above the dose typically used to correct the deficiency and exert effects beyond their functional role as enzyme cofactors. Moreover, the interrelationships between these nutrients can be leveraged to obtain synergistic effects using combinations. The present review discusses the current evidence for using vitamins, minerals, and cofactors in autism spectrum disorder, the rationale behind their use, and the prospects for future use.

Downregulation of DDIT4 ameliorates abnormal behaviors in autism by inhibiting ferroptosis via the PI3K/Akt pathway

Autism spectrum disorder (ASD) is a complex disease with unclear etiology. Studies have shown that ferroptosis is also related to ASD progression, but the specific mechanism is still unclear. Valproic acid (VPA) induced neuronal ferroptosis in vitro. Mechanistic studies showed that both VPA and ferroptosis inducers promoted the expression of DDIT4 in neurons, thereby inhibiting the activation of the PI3K/Akt pathway. DDIT4 increased the accumulation of ROS, MDA and Fe²⁺, inhibited neuronal viability and downregulated GPX4 expression by inactivating the PI3K/Akt pathway. Ferroptosis inhibitors reversed the anti-survival effect of DDIT4, indicating that DDIT4 enhances ferroptosis through the PI3K/Akt pathway, thereby inhibiting neuronal viability. Further in vivo experiments found that autistic mice had high levels of ROS, MDA and Fe²⁺, increased DDIT4 expression, and downregulated expression levels of GPX4, p-PI3K and p-Akt; after downregulation of DDIT4 expression, the accumulation of ROS, MDA and Fe²⁺ was significantly reduced, while the expression levels of GPX4, p-PI3K and p-Akt were upregulated, indicating that DDIT4 knockdown reduces ferroptosis in autistic mice. In addition, DDIT4 downregulation, PI3K/Akt pathway activation, and ferroptosis inhibitors all improved social behavior deficits, repetitive stereotyped and compulsive behaviors, anxiety and exploratory behaviors in autistic mice, but PI3K/Akt pathway inhibitors significantly blocked the rescue of abnormal behaviors by DDIT4 downregulation in autistic mice. Therefore, downregulation of DDIT4 expression ameliorates abnormal behaviors in autism by inhibiting ferroptosis via the PI3K/Akt pathway, indicating that DDIT4, the PI3K/Akt pathway and ferroptosis have key roles in autism.

Recent advances in ferroptosis and therapeutic strategies for glioblastoma

Ferroptosis is an emerging form of cell death characterized by the over-accumulation of iron-dependent lipid peroxidation. Ferroptosis directly or indirectly disturbs glutathione peroxidases cycle through diverse pathways, impacting the cellular antioxidant capacities, aggravating accumulation of reactive oxygen species in lipid, and it finally causes oxidative overload and cell death. Ferroptosis plays a significant role in the pathophysiological processes of many diseases. Glioblastoma is one of the most common primary malignant brain tumors in the central nervous system in adults. Although there are many treatment plans for it, such as surgical resection, radiotherapy, and chemotherapy, they are currently ineffective and the recurrent rate is almost up to 100%. The therapies abovementioned have a strong relationship with ferroptosis at the cellular and molecular level according to the results reported by numerous researchers. The regulation of ferroptosis can significantly determine the outcome of the cells of glioblastoma. Thus ferroptosis, as a regulated form of programed cell death, has the possibility for treating glioblastoma.

Selenomethionine Alleviates DON-Induced Oxidative Stress via Modulating Keap1/Nrf2 Signaling in the Small Intestinal Epithelium

The small intestinal epithelium is regulated in response to various beneficial or harmful environmental information. Deoxynivalenol (DON), a mycotoxin widely distributed in cereal-based feeds, induces oxidative stress damage in the intestine due to the mitochondrial stress. As a functional nutrient, selenomethionine (Se-Met) is involved in synthesizing several antioxidant enzymes, yet whether it can replenish the intestinal epithelium upon DON exposure remains unknown. Therefore, the in vivo model C57BL/6 mice and the in vitro model MODE-K cells were treated with l-Se-Met and DON alone or in combination to confirm the status of intestinal stem cell (ISC)-driven epithelial regeneration. The results showed that 0.1 mg/kg body weight (BW) Se-Met reinstated the growth performance and integrity of jejunal structure and barrier function in DON-challenged mice. Moreover, Lgr5⁺ ISCs and PCNA⁺ mitotic cells in crypts were prominently increased by Se-Met in the presence of DON, concomitant with a significant increase in absorptive cells, goblet cells, and Paneth cells. Simultaneously, crypt-derived jejunal organoids from the Se-Met + DON group exhibited more significant growth advantages ex vivo. Furthermore, Se-Met-stimulated Keap1/Nrf2-dependent antioxidant system (T-AOC and GSH-Px) to inhibit the accumulation of ROS and MDA in the jejunum and serum. Moreover, Se-Met failed to rescue the DON-triggered impairment of cell antioxidant function after Nrf2 perturbation using its specific inhibitor ML385 in MODE-K cells. In conclusion, Se-Met protects ISC-driven intestinal epithelial integrity against DON-induced oxidative stress damage by modulating Keap1/Nrf2 signaling.

Inductively coupled plasma mass spectrometry based urine metallome to construct clinical decision models for autism spectrum disorder

BACKGROUND

The global prevalence of autism spectrum disorder (ASD) is on the rise, and high levels of exposure to toxic heavy metals may be associated with this increase. Urine analysis is a noninvasive method for investigating the accumulation and excretion of heavy metals. The aim of this study was to identify ASD-associated urinary metal markers.

METHODS

Overall, 70 children with ASD and 71 children with typical development (TD) were enrolled in this retrospective case-control study. In this metallomics investigation, inductively coupled plasma mass spectrometry was performed to obtain the urine profile of 27 metals.

RESULTS

Children with ASD could be distinguished from children with TD based on the urine metal profile, with ASD children showing an increased urine metal Shannon diversity. A metallome-wide association analysis was used to identify seven ASD-related metals in urine, with cobalt, aluminum, selenium, and lithium significantly higher, and manganese, mercury, and titanium significantly lower in the urine of children with ASD than in children with TD. The least absolute shrinkage and selection operator (LASSO) machine learning method was used to rank the seven urine metals in terms of their effect on ASD. On the basis of these seven urine metals, we constructed a LASSO regression model for ASD classification and found an area under the receiver operating characteristic curve of 0.913. We also constructed a clinical prediction model for ASD based on the seven metals that were different in the urine of children with ASD and found that the model would be useful for the clinical prediction of ASD risk.

CONCLUSIONS

The study findings suggest that altered urine metal concentrations may be an important risk factor for ASD, and we recommend further exploration of the mechanisms and clinical treatment measures for such alterations.

Organophosphorus flame retardant TDCPP induces neurotoxicity via mitophagy-related ferroptosis in vivo and in vitro

Tris (1,3-dichloro-2-propyl) phosphate (TDCPP) has neurotoxicity, but its mechanism remains unclear. Evidence recently showed that ferroptosis might be associated with TDCPP-induced neurotoxicity. To explore the role and underlying mechanism of ferroptosis in TDCPP-induced neurotoxicity, the occurrence of ferroptosis was examined in mice and PC12 cells upon TDCPP exposure. The mechanism of TDCPP-induced ferroptosis was clarified in vitro combined with the RNA sequencing assay. The in vivo results showed that orally TDCPP exposure (100 mg/kg, 30 d) inhibited the learning and memory ability of mice, reduced hippocampus neurons, induced malondialdehyde (MDA) accumulation, and decreased glutathione (GSH) and superoxide dismutase (SOD) levels in the hippocampus. Moreover, TDCPP exposure (100 mg/kg, 30 d) altered the ferroptosis and autophagy-related protein abundances in the hippocampus. The in vitro results showed that TDCPP exposure (0, 5, 20, 50, 100, and 200 μM) for 24 h induced dose-dependent cell death in PC12 cells, and the cell death was ameliorated by the co-treatment with ferrostatin-1 (1 μM, 24 h). Similarly, TDCPP exposure (0, 50, 100, and 200 μM) for 24 h increased the levels of MDA and LPO, but decreased the reduced GSH in PC12 cells. Furthermore, TDCPP exposure (0, 50, 100, and 200 μM) for 24 h altered the ferroptosis and autophagy-related protein abundances in PC12 cells. The RNA-sequencing revealed that TDCPP exposure (100 μM, 24 h) induced mitophagy activation in SH-SY5Y cells. Meanwhile, the in vitro experiments confirmed that TDCPP exposure (0, 50, 100, and 200 μM) for 24 h increased abundances of mitophagy-related protein phosphatase and tensin homolog induced kinase 1(PINK1), Parkinson protein 2 E3 ubiquitin-protein ligase (PARKIN), inositol 1,4,5-trisphosphate receptor type 1 (IP3R1), and voltage-dependent anion channel 1 (VDAC1) in PC12 cells. Moreover, TDCPP treatment (100 μM, 24 h) increased the mitochondrial recruitment of PARKIN, decreased the mitochondrial membrane potential (MMP) level, and increased the Fe²⁺ level in mitochondria. In addition, decreased ATP levels and increased reactive oxygen species (ROS) levels were observed in PC12 cells upon TDCPP exposure (0, 50, 100, and 200 μM) for 24 h. In summary, ferroptosis was associated with TDCPP-induced neurotoxicity, and the mechanism might be related to PINK1/PARKIN-mediated mitophagy initiated by mitochondrial damage.

Seleno-Metabolites and Their Precursors: A New Dawn for Several Illnesses?

Selenium (Se) is an essential element for human health as it is involved in different physiological functions. Moreover, a great number of Se compounds can be considered potential agents in the prevention and treatment of some diseases. It is widely recognized that Se activity is related to multiple factors, such as its chemical form, dose, and its metabolism. The understanding of its complex biochemistry is necessary as it has been demonstrated that the metabolites of the Se molecules used to be the ones that exert the biological activity. Therefore, the aim of this review is to summarize the recent information about its most remarkable metabolites of acknowledged biological effects: hydrogen selenide (HSe⁻/H₂Se) and methylselenol (CH₃SeH). In addition, special attention is paid to the main seleno-containing precursors of these derivatives and their role in different pathologies.

Identification of Ferroptosis-Related Molecular Clusters and Immune Characterization in Autism Spectrum Disorder

Introduction: Autism spectrum disorder (ASD) is a neurodevelopmental disorder with clinical presentation and prognostic heterogeneity. Ferroptosis is a regulated non-apoptotic cell death program implicated in the occurrence and progression of various diseases. Therefore, we aimed to explore ferroptosis-related molecular subtypes in ASD and further illustrate the potential mechanism.

Methods: A total of 201 normal samples and 293 ASD samples were obtained from the Gene Expression Omnibus (GEO) database. We used the unsupervised clustering analysis to identify the molecular subtypes based on ferroptosis-related genes (FRGs) and evaluate the immune characteristics between ferroptosis subtypes. Ferroptosis signatures were identified using the least absolute shrinkage and selection operator regression (LASSO) and recursive feature elimination for support vector machines (SVM-RFE) machine learning algorithms. The ferroptosis scores based on seven selected genes were constructed to evaluate the ferroptosis characteristics of ASD.

Results: We identified 16 differentially expressed FRGs in ASD children compared with controls. Two distinct molecular clusters associated with ferroptosis were identified in ASD. Analysis of immune infiltration revealed immune heterogeneity between the two clusters. Cluster2, characterized by a higher immune score and a larger number of infiltrated immune cells, exhibited a stronger immune response and was markedly enriched in immune response-related signaling pathways. Additionally, the ferroptosis scores model was capable of predicting ASD subtypes and immunity. Higher levels of ferroptosis scores were associated with immune activation, as seen in Cluster2. Lower ferroptosis scores were accompanied by relative immune downregulation, as seen in Cluster1.

Conclusion: Our study systematically elucidated the intricate correlation between ferroptosis and ASD and provided a promising ferroptosis score model to predict the molecular clusters and immune infiltration cell profiles of children with ASD.

A white paper on Phospholipid Hydroperoxide Glutathione Peroxidase (GPx4) forty years later

The purification of a protein inhibiting lipid peroxidation led to the discovery of the selenoperoxidase GPx4 forty years ago. Thus, the evidence of the enzymatic activity was reached after identifying the biological effect and unambiguously defined the relationship between the biological function and the enzymatic activity. In the syllogism where GPx4 inhibits lipid peroxidation and its inhibition is lethal, cell death is operated by lipid peroxidation. Based on this rationale, this form of cell death emerged as regulated iron-enforced oxygen toxicity and was named ferroptosis in 2012. In the last decades, we learned that reduction of lipid hydroperoxides is indispensable and, in cooperation with prooxidant systems, controls the critical steady state of lipid peroxidation. This concept defined the GPx4 reaction as both the target for possible anti-cancer therapy and if insufficient, as cause of degenerative diseases. We know the reaction mechanism, but the details of the interaction at the membrane cytosol interface are still poorly defined. We know the gene structure, but the knowledge about expression control is still limited. The same holds true for post-transcriptional modifications. Reverse genetics indicate that GPx4 has a role in inflammation, immunity, and differentiation, but the observations emerging from these studies need a more specifically addressed biochemical evidence. Finally, the role of GPx4 in spermatogenesis disclosed an area unconnected to lipid peroxidation. In its mitochondrial and nuclear form, the peroxidase catalyzes the oxidation of protein thiols in two specific aspects of sperm maturation: stabilization of the mid-piece and chromatin compaction. Thus, although available evidence converges to the notion that GPx4 activity is vital due to the inhibition of lipid peroxidation, it is reasonable to foresee other unknown aspects of the GPx4 reaction to be disclosed.