RNA-seq combined network pharmacology reveals that Fu-Gan-Wan (FGW) inhibits liver fibrosis via NF-κB/CCL2/CCR2 and lipid peroxidation via Nrf2/HMOX1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Liver fibrosis is a serious complication of liver disease characterized by excessive collagen deposition, without effective therapeutic agents in the clinic. Fu-Gan-Wan (FGW) is an empirical formula used for the clinical treatment of hepatitis and cirrhosis. It has been shown to reverse experimental liver fibrosis. However, its corresponding mechanisms remain unclear.

AIM OF THE REVIEW

This study aimed to elucidate the key pathways and target genes of FGW in attenuating liver fibrosis.

MATERIALS AND METHODS

The therapeutic effects of different doses of FGW on liver fibrosis were investigated using a 2 mL/kg 15% CCl4-induced mouse model. Then, RNA-seq combined with network pharmacology was used to analyze the key biological processes and signaling pathways underlying the anti-liver fibrosis exertion of FGW. These findings were validated in a TGF-β1-induced model of activation and proliferation of mouse hepatic stellate cell line JS-1. Finally, the key signaling pathways and molecular targets were validated using animal tissues, and the effect of FGW on tissue lipid peroxidation was additionally observed.

RESULTS

We found that 19.5 g/kg FGW significantly down-regulated CCl4-induced elevation of hepatic ALT and AST, decreased collagen deposition, and inhibited the expression of pro-fibrotic factors α-SMA, COL1α1, CTGF, TIMP-1, as well as pro-inflammatory factor TGF-β1. Additionally, FGW at doses of 62.5, 125, and 250 μg/mL dose-dependently blocked JS-1 proliferation, migration, and activation. Furthermore, RNA-seq identified the NF-κB signaling pathway as a key target molecular pathway for FGW against liver fibrosis, and network pharmacology combined with RNA-seq focused on 11 key genes. Significant changes were identified in CCL2 and HMOX1 by tissue RT-PCR, Western blot, and immunohistochemistry. We further demonstrated that FGW significantly attenuated CCl4-induced increases in p-p65, CCL2, CCR2, and HMOX1, while significantly elevating Nrf2. Finally, FGW significantly suppressed the accumulation of lipid peroxidation products MDA and 4-HNE and reconfigured the oxidation-reduction balance, including promoting the increase of antioxidants GPx, GSH, and SOD, and the decrease of peroxidation products ROS and GSSG.

CONCLUSIONS

This study demonstrated that FGW exhibits potential in mitigating CCl4-induced hepatic fibrosis, lipid peroxidation, and iron metabolism disorders in mice. This effect may be mediated through the NF-κB/CCL2/CCR2 and Nrf2/HMOX1 pathways.

Understanding the transition to viable but non-culturable state in Escherichia coli W3110: a comprehensive analysis of potential spectrochemical biomarkers

The viable but non-culturable (VBNC) state is considered a survival strategy employed by bacteria to endure stressful conditions, allowing them to stay alive. Bacteria in this state remain unnoticed in live cell counts as they cannot proliferate in standard culture media. VBNC cells pose a significant health risk because they retain their virulence and can revive when conditions normalize. Hence, it is crucial to develop fast, reliable, and cost-effective methods to detect bacteria in the VBNC state, particularly in the context of public health, food safety, and microbial control assessments. This research examined the biomolecular changes in Escherichia coli W3110 induced into the VBNC state in artificial seawater under three different stress conditions (temperature, metal, and antibiotic). Initially, confirmation of VBNC cells under various stresses was done using fluorescence microscopy and plate counts. Subsequently, lipid peroxidation was assessed through the TBARS assay, revealing a notable increase in peroxidation end-products in VBNC cells compared to controls. ATR-FTIR spectroscopy and chemomometrics were employed to analyze biomolecular changes, uncovering significant spectral differences in RNA, protein, and nucleic acid concentrations in VBNC cells compared to controls. Notably, RNA levels increased, while protein and nucleic acid amounts decreased. ROC analyses identified the 995 cm- 1 RNA band as a consistent marker across all studied stress conditions, suggesting its potential as a robust biomarker for detecting cells induced into the VBNC state under various stressors.

High-throughput synchronous erythrocyte cellular antioxidant activity and protection screening of phenolic-rich extracts: Protocol validation and applications

Oxidative/nitrosative damage takes part in chronic disease development, which generates an urgent need for intervention and better therapies to manage them. The scientific community has demanded easy-to-run, cheap, and reliable methods for cellular antioxidant activity assays. This work standardised and validated an erythrocyte cellular antioxidant activity and membrane protection/injury (HERYCA-P) protocol to study food-derive extracts. The method measures intracellular reactive oxygen species (ROS) generation, lipoperoxidation, and haemolysis induced by 2,2'-azobis(2-amidinopropane) dihydrochloride. Quercetin decreased ROS generation by 50.4% and haemolysis by 2.2%, while ascorbic acid inhibited lipid peroxidation by 40.1%. Total phenolic contents of teas were correlated with decreased ROS generation (r = -0.924), lipoperoxidation (r = -0.951), and haemolysis (r = -0.869). The erythrocyte ROS generation and lipoperoxidation were also associated with CUPRAC (r = -0.925; r = -0.951) and hydroxyl radical scavenging activity (r = -0.936; r = -0.949). The precision rates of antioxidant standards and tea samples were below 15%. HERYCA-P is feasible as a complementary antioxidant assay for food matrices.

H2S is involved in drought-mediated stomatal closure through PLDα1 in Arabidopsis

MAIN CONCLUSION

PLDα1 promoted H2S production by positively regulating the expression of LCD. Stomatal closure promoted by PLDα1 required the accumulation of H2S under drought stress. Phospholipase Dα1 (PLDα1) acting as one of the signal enzymes can respond to drought stress. It is well known that hydrogen sulfide (H2S) plays an important role in plant responding to biotic or abiotic stress. In this study, the functions and relationship between PLDα1 and H2S in drought stress resistance in Arabidopsis were explored. Our results indicated that drought stress promotes PLDα1 and H2S production by inducing the expression of PLDα1 and LCD genes. PLDα1 and LCD enhanced plant tolerance to drought by regulating membrane lipid peroxidation, proline accumulation, H2O2 content and stomatal closure. Under drought stress, the H2O2 content of PLDα1-deficient mutant (pldα1), L-cysteine desulfhydrase (LCD)-deficient mutant (lcd) was higher than that of ecotype (WT), the stomatal aperture of pldα1 and lcd was larger than that of WT. The transcriptional and translational levels of LCD were lower in pldα1 than that in WT. Exogenous application of the H2S donor NaHS or GYY reduced the stomatal aperture of WT, pldα1, PLDα1-CO, and PLDα1-OE lines, while exogenous application of the H2S scavenger hypotaurine (HT) increased the stomatal aperture. qRT-PCR analysis of stomatal movement-related genes showed that the expression of CAX1, ABCG5, SCAB1, and SLAC1 genes in pldα1 and lcd were down-regulated, while ACA1 and OST1 gene expression was significantly up-regulated. Thus, PLDα1 and LCD are required for stomatal closure to improve drought stress tolerance.

Alcohol-induced hormonal and metabolic alterations in plasma and erythrocytes-a gender-based study

PURPOSE

This study aimed to understand the gender-specific alcohol-induced biochemical changes and TBARS association with the endocrine system.

METHODS

Human male and female subjects ranging from 35 ± 10 years old with an 8-10-year drinking history were included in the study.

RESULTS

The results demonstrated that testosterone levels were lower in male alcoholics and higher in female alcoholics, as well as higher estrogen and cortisol levels in both genders. In addition, we found lower T3, T4, and thyroid-stimulating hormone (TSH) levels in alcoholics of both sexes. Furthermore, plasma TBARS, protein carbonyls, nitrite, and nitrate levels increased significantly with concomitant decrease in reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in both male and female alcoholics. Furthermore, erythrocyte lysate nitrite and nitrate levels membrane total cholesterol, phospholipid and cholesterol/phospholipid (C/P) ratio with lower total membrane proteins in both genders of alcoholics. SDS-PAGE analysis of erythrocyte membrane proteins revealed increased density of band 3, protein 4.1, 4.2, 4.9 and glycophorins, whereas decreases in spectrin (α and β) were observed in both genders of alcoholics. Besides, alcoholics of both sexes had a lower ability to resist osmotic hemolysis. Plasma TBARS was negatively correlated with testosterone, TSH, T3 and T4 in male alcoholics, moreover, estradiol and cortisol were positively correlated in males and females respectively.

CONCLUSION

Female alcoholics may be more susceptible to osmotic hemolysis due to increased erythrocyte membrane lipid peroxidation with decreased antioxidant status, which results in an altered membrane C/P ratio and membrane protein composition.

Changes in the blood redox status of horses subjected to combat training

Combat training of police horses, involving physical activity in the presence of environmental stressors, poses a risk of oxidative stress. This study compared the oxidative imbalance after combat training in horses in the regular police service and in horses that had just been schooled. Blood collection was performed immediately after training and after 16 h rest. The activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and total antioxidant status (TAS) were determined as the markers of enzymatic antioxidant defence. At the same time, lipid peroxidation (TBARS) and protein carbonylation (Carb) were assessed as oxidation biomarkers. Additionally, oxidative imbalance indexes such as SOD/CAT, SOD/GPx, TBARS/TAS and TBARS/GPx were calculated. Animals during schooling had significantly lower SOD activity in erythrocytes than those experienced. CAT activity in erythrocytes was insignificantly higher immediately after training than during recovery. The SOD/GPx ratio was higher in experienced animals, which may reflect the intra-erythrocyte imbalance between enzymes producing and degrading hydrogen peroxide towards the first one. The concentration of carbonyl groups was significantly higher after the combat training compared to the recovery period in all horses. In inexperienced animals slight increase in TBARS/TAS and TBARS/GPx indexes were observed during the recovery time after exercises, contrary to experienced horses, in which these markers decreased slightly. These results suggest that the oxidative imbalance in inexperienced horses, although less pronounced just after combat training, was more prolonged as compared to horses in regular service.

LPCAT1-mediated membrane phospholipid remodelling promotes ferroptosis evasion and tumour growth

The mechanisms underlying the dynamic remodelling of cellular membrane phospholipids to prevent phospholipid peroxidation-induced membrane damage and evade ferroptosis, a non-apoptotic form of cell death driven by iron-dependent lipid peroxidation, remain poorly understood. Here we show that lysophosphatidylcholine acyltransferase 1 (LPCAT1) plays a critical role in ferroptosis resistance by increasing membrane phospholipid saturation via the Lands cycle, thereby reducing membrane levels of polyunsaturated fatty acids, protecting cells from phospholipid peroxidation-induced membrane damage and inhibiting ferroptosis. Furthermore, the enhanced in vivo tumour-forming capability of tumour cells is closely associated with the upregulation of LPCAT1 and emergence of a ferroptosis-resistant state. Combining LPCAT1 inhibition with a ferroptosis inducer synergistically triggers ferroptosis and suppresses tumour growth. Therefore, our results unveil a plausible role for LPCAT1 in evading ferroptosis and suggest it as a promising target for clinical intervention in human cancer.

Selenoprotein I is indispensable for ether lipid homeostasis and proper myelination

Selenoprotein I (SELENOI) catalyzes the final reaction of the CDP-ethanolamine branch of the Kennedy pathway, generating the phospholipids phosphatidylethanolamine (PE) and plasmenyl-PE. Plasmenyl-PE is a key component of myelin and is characterized by a vinyl ether bond that preferentially reacts with oxidants, thus serves as a sacrificial antioxidant. In humans, multiple loss-of-function mutations in genes affecting plasmenyl-PE metabolism have been implicated in hereditary spastic paraplegia, including SELENOI. Herein, we developed a mouse model of nervous system-restricted SELENOI deficiency that circumvents embryonic lethality caused by constitutive deletion and recapitulates phenotypic features of hereditary spastic paraplegia. Resulting mice exhibited pronounced alterations in brain lipid composition, which coincided with motor deficits and neuropathology including hypomyelination, elevated reactive gliosis, and microcephaly. Further studies revealed increased lipid peroxidation in oligodendrocyte lineage cells and disrupted oligodendrocyte maturation both in vivo and in vitro. Altogether, these findings detail a critical role for SELENOI-derived plasmenyl-PE in myelination that is of paramount importance for neurodevelopment.

Sensitivity of different organs and tissues as biomarkers of oxidative stress in juvenile tambaqui (Colossoma macropomum) submitted to fasting

The present study was conducted to evaluate the effects of fasting on responses of oxidative biomarkers and antioxidant defenses using different organs and tissues of Colossoma macropomum. The fish were divided into two groups: fed (control) and fasting (7 days). After 7 days, the fish were sampled for assessment of oxidative stress biomarkers (MDA-lipid peroxidation and PCO-protein carbonyl) and antioxidant defenses (SOD-superoxide dismutase; CAT-catalase; GPX-glutathione peroxidase; and GST-glutathione-S -transferase) in the liver, intestine, gills, muscle, brain, and plasma. The results showed an increase in MDA, PCO, SOD, and GPX concentrations in the liver and intestine of fasting fish. In contrast, in the branchial tissue, there was a reduction in the activity of SOD and CAT enzymes in fasting fish. There was also a reduction in CAT activity in the muscle of fasting fish, while in the brain, there were no changes in oxidative stress biomarkers. Plasma showed a relatively low antioxidant response. In conclusion, our results confirm that a 7-day fasting period induced tissue-specific antioxidant responses, but the increase in antioxidant responses was only for the SOD and GPX enzymes of the liver and intestine. Additionally, the liver and intestine were the most responsive tissues, whereas the plasma was the least sensitive to oxidative stress.

circFAM193B interaction with PRMT6 regulates AML leukemia stem cells chemoresistance through altering the oxidative metabolism and lipid peroxidation

Most forms of chemotherapy for acute myeloid leukemia (AML) are often ineffective in eliminating leukemic stem cells (LSCs), as their underlying mechanisms remain unclear. Here, we have identified circFAM193B, which regulates the redox biology of LSCs and is associated with unfavorable outcomes in AML patients. In vitro and in vivo assays suggested that circFAM193B significantly inhibits LSCs chemotherapy resistance and AML progression. Knockdown circFAM193B enhances mitochondrial OXPHOS function and inhibits the accumulation of reactive oxygen species and lipid peroxidation mediated by chemotherapy, which protects AML cells from oxidative stress-induced cell death. Mechanistically, circFAM193B physically interacts with arginine methyltransferase PRMT6 catalytic domain and enhances the transcription efficiency of key lipid peroxidation factor ALOX15 by decreasing H3R2me2a modification. In summary, we have identified circFAM193B was downregulated in LSCs to promote the survival of LSC by modulating energy metabolism and the redox balance in the postchemotherapy persistence of LSC. Our studies provide a conceptual advance and biological insights regarding the drug resistance of LSCs via circRNA mediated PRMT6-deposited methylarginine signaling.

Adjusting ram semen preservation: Exploring the impact of oxygen exposure during liquid storage

This study investigated the effects of storage conditions on the quality of chilled ram semen stored at 4°C for 48 h, comparing aerobic and anaerobic conditions. Ejaculates from INRA180 rams were collected and stored under both conditions, with assessments at 0-, 24-, and 48-h intervals. Various sperm parameters were examined, including motility, velocity, viability, morphology, membrane integrity, and lipid peroxidation. Results showed that storage duration significantly impacted sperm quality, leading to a gradual decline from 0 to 24 h and 24 to 48 h. Notably, after the initial 24 h, progressive motility (PM) and membrane integrity (MI) demonstrated distinct responses to storage conditions. Anaerobic storage consistently improved PM and MI values compared to aerobic storage between 24 and 48 h. Anaerobic conditions also enhanced viability and reduced abnormality at the 48-h mark. Total motility remained stable throughout storage. Velocity parameters (VCL: curvilinear velocity; VSL: straight velocity and VAP: velocity average path) exhibited differences between the 24- and 48-h intervals, with anaerobic storage resulting in higher VAP and VSL values. Moreover, lipid peroxidation exhibited a progressive increase from 0 to 24 h and 24 to 48 h, independent of storage conditions. Remarkably, anaerobic storage consistently yielded lower lipid peroxidation levels compared to aerobic storage, regardless of storage duration. In conclusion, this study highlights that the anaerobic storage proved advantageous for chilled ram semen quality, particularly after the initial 24 h.

The role of warming in modulating neodymium effects on adults and sperm of Mytilus galloprovincialis

The use of rare earth elements (REEs) has been increasing and one of the most used is neodymium (Nd). Being an emergent contaminant, its negative impacts are poorly understood. Aquatic organisms are also threatened by climate change-related factors, as is the case of warming, which can change the effects of REEs. Thus, the impacts of Nd, warming, and the combination of both stressors were studied in adult mussels and sperm of the species Mytilus galloprovincialis, after an exposure period of 28 days (adults) and 30 min (sperm). The effects were evaluated through the analysis of biochemical and histopathological alterations in adults and biochemical and physiological responses given by sperm. The results showed that mussels only activated their biotransformation capacity when exposed to the stressors acting alone, which was insufficient to avoid lipid peroxidation. Furthermore, warming (alone and combined with Nd) also produces damage to proteins. The digestive gland was the most sensitive organ to Nd, presenting several histopathological alterations. In the case of sperm, all stressors induced lipid peroxidation, a higher oxygen demand, and a decrease in velocity, even if the sperm viability was maintained. It seems that warming influenced the effects of Nd to some extent. The present findings contribute significantly to the field of REEs environmental toxicology by offering valuable insights into the impacts of Nd on various biological levels of mussels. Additionally, within the context of climate change, this study sheds light on how temperature influences the effects of Nd. The obtained results indicate that both stressors can potentially compromise the overall health of mussel populations, thereby affecting other species reliant on them for food and habitat. Moreover, this study highlights impaired sperm health, which could adversely affect their reproductive capacity and ultimately lead to population decline.

Comparison of oxidative stress, lipid peroxidation and inflammatory markers between rheumatoid arthritis and ankylosing spondylitis patients

Objectives

To measure the levels of superoxide dismutase and malondialdehyde along with erythrocyte sedimentation rate and C-reactive protein in patients of rheumatoid arthritis and ankylosing spondylitis.

METHODS

The comparative, cross-sectional study was conducted from February 2 to December 30, 2022, at the Centre for Research in Experimental and Applied Medicine laboratory of the Department of Biochemistry and Molecular Biology, Army Medical College, Rawalpindi, Pakistan, in collaboration with the Department of Rheumatology, Pak Emirates Military Hospital, Rawalpindi. The sample comprised healthy controls in group 1, patients of rheumatoid arthritis in group 2 and patients of ankylosing spondylitis in group 3. Blood samples were assessed for levels of superoxide dismutase, malondialdehyde, erythrocyte sedimentation rate and C-reactive protein. Data was analysed using SPSS 25.

RESULTS

Of the 180 subjects, 60(33.3%) were in group 1; 32(53.3%) females and 28(46.7%) males with mean age 34.9±6.4 years. There were 60(33.3%) patients in group 2; 35(58.3%) females and 25(41.7%) males with mean age 46.0±11.1 years. There were 60(33.3%) patients in group 3, and all 60(100%) were males with mean age 35.9±6.9 years. Superoxide dismutase level was significantly low and malondialdehyde level was significantly high in groups 2 and 3 compared to group 1 (p<0.05). Erythrocyte sedimentation rate was the highest in group 2, followed by group 3 (p<0.05). C-reactive protein levels were the highest in group 2 and the lowest in group 3 (p<0.05). A significantly negative correlation (p<0.001) was found between superoxide dismutase and malondialdehyde.

CONCLUSIONS

Oxidative stress played a pivotal role in chronic inflammatory rheumatic diseases, like rheumatoid arthritis and ankylosing spondylitis.

Impact of changes in root biomass on the occurrence of internal browning in radish root

The purpose of this study was to investigate the effects of root biomass during the later stage of growth on fatty acid composition and lipid peroxidation, and to clarify the physiological mechanisms by which these differences affect internal browning (IB) development in radish roots. Therefore, we controlled the enlargement of roots by changing the thinning period and generated plots composed of roots with different biomass in the latter half of growth. The earlier the radish seedlings were thinned, the more vigorous the root growth from an earlier stage was achieved. Earlier thinning caused IB from the early stage of root maturation, and IB severity progressed with subsequent age progression; however, IB damage did not occur when root size during the later growth stage was kept small by later thinning. Higher levels of hydrogen peroxide, peroxidase activity, NADPH-dependent reactive oxygen species (ROS) burst-related genes, and carbonyl compounds were detected in earlier-thinned large-sized roots compared to later-thinned small-sized ones. Compared with the latter small-sized roots, the former large-sized roots had a lower ratio of linoleic acid (18:2) and a higher ratio of α-linolenic acid (α-18:3). Furthermore, in earlier-thinned large-sized roots, higher levels of phospholipase- and/or lipoxygenase-related genes were detected compared to later-thinned small-sized ones. These facts suggest the possibility that root biomass in the later stage of growth affects the desaturation of membrane fatty acids, ROS concentration, and activity of fatty acid degrading enzymes, and controls the occurrence of IB injury through membrane oxidative degradation.

A Bimetallic Polymerization Network for Effective Increase in Labile Iron Pool and Robust Activation of cGAS/STING Induces Ferroptosis-Based Tumor Immunotherapy

Due to the inherent low immunogenicity and immunosuppressive tumor microenvironment (TME) of malignant cancers, the clinical efficacy and application of tumor immunotherapy have been limited. Herein, a bimetallic drug-gene co-loading network (Cu/ZIF-8@U-104@siNFS1-HA) is developed that increased the intracellular labile iron pool (LIP) and enhanced the weakly acidic TME by co-suppressing the dual enzymatic activities of carbonic anhydrase IX (CA IX) and cysteine desulfurylase (NFS1), inducing a safe and efficient initial tumor immunogenic ferroptosis. During this process, Cu2+ is responsively released to deplete glutathione (GSH) and reduce the enzyme activity of glutathione peroxidase 4 (GPX4), achieving the co-inhibition of the three enzymes and further inducing lipid peroxidation (LPO). Additionally, the reactive oxygen species (ROS) storm in target cells promoted the generation of large numbers of double-stranded DNA breaks. The presence of Zn2+ substantially increased the expression of cGAS/STING, which cooperated with ferroptosis to strengthen the immunogenic cell death (ICD) response and remodel the immunosuppressive TME. In brief, Cu/ZIF-8@U-104@siNFS1-HA linked ferroptosis with immunotherapy through multiple pathways, including the increase in LIP, regulation of pH, depletion of GSH/GPX4, and activation of STING, effectively inhibiting cancer growth and metastasis.

Icariin, astragaloside a and puerarin mixture attenuates cognitive impairment in APP/PS1 mice via inhibition of ferroptosis-lipid peroxidation

Alzheimer's disease (AD) is a neurodegenerative disease that seriously threatens the quality of life of the elderly. Its pathogenesis has not yet been fully elucidated. Ferroptosis, a cell death caused by excessive accumulation of iron-dependent lipid peroxides, has been implicated in the pathogenesis of AD. Uncontrolled lipid peroxidation is the core process of ferroptosis, and inhibiting lipid peroxidation of ferroptosis may be an important therapeutic target for AD. Based on previous studies, we mixed standards of icariin, astragaloside IV, and puerarin, named the standard mixture YHG, and investigated the effect of YHG on ferroptosis -lipid peroxidation in APP/PS1 mice. DFX, a ferroptosis inhibitor, was used as a control drug. In this study, APP/PS1 mice were used as an AD animal model, and behavioral experiments, iron level detection, Transmission electron microscopy (TEM) observation, lipid peroxidation level detection, antioxidant capacity detection, immunofluorescence, Western blot and real-time qPCR were performed. It was found that YHG could reduce body weight, significantly improve abnormal behaviors and the ultrastructure of hippocampal neurons in APP/PS1 mice. The results of biochemical tests showed that YHG reduced the contents of iron, malondialdehyde (MDA) and lipid peroxide (LPO) in brain tissue and serum, and increased the levels of superoxide dismutase (SOD) and reduced glutathione (GSH). Immunofluorescence, WesternBlot and real-time qPCR results showed that YHG could promote the expression of solute carrier family 7 member 11 (SLC7A11), solute carrier family 3 member 2 (SLC3A2) and glutathione peroxidase 4(GPX4). Inhibited the expression of long-chain acyllipid coenzyme a synthetase 4(ACSL4) and lysophosphatidyltransferase 3 (LPCAT3). This study suggests that the mechanism by which YHG improves cognitive dysfunction in APP/PS1 mice may be related to the inhibition of ferroptosis-lipid peroxidation.

New insights on neurodegeneration triggered by iron accumulation: Intersections with neutral lipid metabolism, ferroptosis, and motor impairment

Brain iron accumulation constitutes a pathognomonic indicator in several neurodegenerative disorders. Metal accumulation associated with dopaminergic neuronal death has been documented in Parkinson's disease. Through the use of in vivo and in vitro models, we demonstrated that lipid dysregulation manifests as a neuronal and glial response during iron overload. In this study, we show that cholesterol content and triacylglycerol (TAG) hydrolysis were strongly elevated in mice midbrain. Lipid cacostasis was concomitant with the loss of dopaminergic neurons, astrogliosis and elevated expression of α-synuclein. Exacerbated lipid peroxidation and markers of ferroptosis were evident in the midbrain from mice challenged with iron overload. An imbalance in the activity of lipolytic and acylation enzymes was identified, favoring neutral lipid hydrolysis, and consequently reducing TAG and cholesteryl ester levels. Notably, these observed alterations were accompanied by motor impairment in iron-treated mice. In addition, neuronal and glial cultures along with their secretomes were used to gain further insight into the mechanism underlying TAG hydrolysis and cholesterol accumulation as cellular responses to iron accumulation. We demonstrated that TAG hydrolysis in neurons is triggered by astrocyte secretomes. Moreover, we found that the ferroptosis inhibitor, ferrostatin-1, effectively prevents cholesterol accumulation both in neurons and astrocytes. Taken together, these results indicate that lipid disturbances occur in iron-overloaded mice as a consequence of iron-induced oxidative stress and depend on neuron-glia crosstalk. Our findings suggest that developing therapies aimed at restoring lipid homeostasis may lead to specific treatment for neurodegeneration associated with ferroptosis and brain iron accumulation.

Identification of a set of genes potentially responsible for resistance to ferroptosis in lung adenocarcinoma cancer stem cells

Scientific literature supports the evidence that cancer stem cells (CSCs) retain inside low reactive oxygen species (ROS) levels and are, therefore, less susceptible to cell death, including ferroptosis, a type of cell death dependent on iron-driven lipid peroxidation. A collection of lung adenocarcinoma (LUAD) primary cell lines derived from malignant pleural effusions (MPEs) of patients was used to obtain 3D spheroids enriched for stem-like properties. We observed that the ferroptosis inducer RSL3 triggered lipid peroxidation and cell death in LUAD cells when grown in 2D conditions; however, when grown in 3D conditions, all cell lines underwent a phenotypic switch, exhibiting substantial resistance to RSL3 and, therefore, protection against ferroptotic cell death. Interestingly, this phenomenon was reversed by disrupting 3D cells and growing them back in adherence, supporting the idea of CSCs plasticity, which holds that cancer cells have the dynamic ability to transition between a CSC state and a non-CSC state. Molecular analyses showed that ferroptosis resistance in 3D spheroids correlated with an increased expression of antioxidant genes and high levels of proteins involved in iron storage and export, indicating protection against oxidative stress and low availability of iron for the initiation of ferroptosis. Moreover, transcriptomic analyses highlighted a novel subset of genes commonly modulated in 3D spheroids and potentially capable of driving ferroptosis protection in LUAD-CSCs, thus allowing to better understand the mechanisms of CSC-mediated drug resistance in tumors.

Therapeutic exploitation of ferroptosis

Pathological breakdown of membrane lipids through excessive lipid peroxidation (LPO) was first described in the mid-20th century and is now recognized as a form of regulated cell death, dubbed ferroptosis. Accumulating evidence unveils how metabolic regulation restrains peroxidation of phospholipids within cellular membranes, thereby impeding ferroptosis execution. Unleashing these metabolic breaks is currently therapeutically explored to sensitize cancers to ferroptosis inducing anti-cancer therapies. Reversely, these natural ferroptotic defense mechanisms can fail resulting in pathological conditions or diseases such as ischemia-reperfusion injury, multi-organ dysfunction, stroke, infarction, or neurodegenerative diseases. This minireview outlines current ferroptosis-inducing anti-cancer strategies and highlights the detection as well as the therapeutic targeting of ferroptosis in preclinical experimental settings. Herein, we also briefly summarize observations related to LPO, iron and redox deregulation in patients that might hint towards ferroptosis as a contributing factor.

Fatty acid-binding protein 5 is a functional biomarker and indicator of ferroptosis in cerebral hypoxia

The progression of human degenerative and hypoxic/ischemic diseases is accompanied by widespread cell death. One death process linking iron-catalyzed reactive species with lipid peroxidation is ferroptosis, which shows hallmarks of both programmed and necrotic death in vitro. While evidence of ferroptosis in neurodegenerative disease is indicated by iron accumulation and involvement of lipids, a stable marker for ferroptosis has not been identified. Its prevalence is thus undetermined in human pathophysiology, impeding recognition of disease areas and clinical investigations with candidate drugs. Here, we identified ferroptosis marker antigens by analyzing surface protein dynamics and discovered a single protein, Fatty Acid-Binding Protein 5 (FABP5), which was stabilized at the cell surface and specifically elevated in ferroptotic cell death. Ectopic expression and lipidomics assays demonstrated that FABP5 drives redistribution of redox-sensitive lipids and ferroptosis sensitivity in a positive-feedback loop, indicating a role as a functional biomarker. Notably, immunodetection of FABP5 in mouse stroke penumbra and in hypoxic postmortem patients was distinctly associated with hypoxically damaged neurons. Retrospective cell death characterized here by the novel ferroptosis biomarker FABP5 thus provides first evidence for a long-hypothesized intrinsic ferroptosis in hypoxia and inaugurates a means for pathological detection of ferroptosis in tissue.

Lipid Peroxidation-Related Redox Signaling in Osteosarcoma

Oxidative stress and lipid peroxidation play important roles in numerous physiological and pathological processes, while the bioactive products of lipid peroxidation, lipid hydroperoxides and reactive aldehydes, act as important mediators of redox signaling in normal and malignant cells. Many types of cancer, including osteosarcoma, express altered redox signaling pathways. Such redox signaling pathways protect cancer cells from the cytotoxic effects of oxidative stress, thus supporting malignant transformation, and eventually from cytotoxic anticancer therapies associated with oxidative stress. In this review, we aim to explore the status of lipid peroxidation in osteosarcoma and highlight the involvement of lipid peroxidation products in redox signaling pathways, including the involvement of lipid peroxidation in osteosarcoma therapies.

Overview of the Lipid Peroxidation Measurements in Patients by the Enzyme-Linked Immunosorbent Assay Specific for the 4-Hydroxynonenal-Protein Adducts (4-HNE-ELISA)

Oxidative stress often affects the structure and metabolism of lipids, which in the case of polyunsaturated free fatty acids (PUFAs) leads to a self-catalysed chain reaction of lipid peroxidation (LPO). The LPO of PUFAs leads to the formation of various aldehydes, such as malondialdehyde, 4-hydroxynonenal (4-HNE), 4-hydroxyhexenal, and 4-oxo-2-nonenal. Among the reactive aldehydes, 4-HNE is the major bioactive product of LPO, which has a high affinity for binding to proteins. This review briefly discusses the available information on the applicability of assessment options for 4-HNE and its protein adducts determined by immunosorbent assay (the 4-HNE-ELISA) in patients with various diseases known to be associated with oxidative stress, LPO, and 4-HNE. Despite the differences in the protocols applied and the antibodies used, all studies confirmed the usefulness of the 4-HNE-ELISA for research purposes. Since different protocols and the antibodies used could give different values when applied to the same samples, the 4-HNE-ELISA should be combined with other complementary analytical methods to allow comparisons between the values obtained in patients and in healthy individuals. Despite large variations, the studies reviewed in this paper have mostly shown significantly increased levels of 4-HNE-protein adducts in the samples obtained from patients when compared to healthy individuals. As with any other biomarker studied in patients, it is preferred to perform not only a single-time analysis but measurements at multiple time points to monitor the dynamics of the occurrence of oxidative stress and the systemic response to the disease causing it. This is especially important for acute diseases, as individual levels of 4-HNE-protein adducts in blood can fluctuate more than threefold within a few days depending on the state of health, as was shown for the COVID-19 patients.

USP8-governed GPX4 homeostasis orchestrates ferroptosis and cancer immunotherapy

Ferroptosis is an iron-dependent type of regulated cell death resulting from extensive lipid peroxidation and plays a critical role in various physiological and pathological processes. However, the regulatory mechanisms for ferroptosis sensitivity remain incompletely understood. Here, we report that homozygous deletion of Usp8 (ubiquitin-specific protease 8) in intestinal epithelial cells (IECs) leads to architectural changes in the colonic epithelium and shortens mouse lifespan accompanied by increased IEC death and signs of lipid peroxidation. However, mice with heterozygous deletion of Usp8 in IECs display normal phenotype and become resistant to azoxymethane/dextran sodium sulfate-induced colorectal tumorigenesis. Mechanistically, USP8 interacts with and deubiquitinates glutathione peroxidase 4 (GPX4), leading to GPX4 stabilization. Thus, USP8 inhibition destabilizes GPX4 and sensitizes cancer cells to ferroptosis in vitro. Notably, USP8 inhibition in combination with ferroptosis inducers retards tumor growth and enhances CD8+ T cell infiltration, which potentiates tumor response to anti-PD-1 immunotherapy in vivo. These findings uncover that USP8 counteracts ferroptosis by stabilizing GPX4 and highlight targeting USP8 as a potential therapeutic strategy to boost ferroptosis for enhancing cancer immunotherapy.

The Role of Oxidative Stress in Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Preclinical Studies

Alcoholic Fatty Liver Disease (AFLD) is characterized by the accumulation of lipids in liver cells owing to the metabolism of ethanol. This process leads to a decrease in the NAD+/NADH ratio and the generation of reactive oxygen species. A systematic review and meta-analysis were conducted to investigate the role of oxidative stress in AFLD. A total of 201 eligible manuscripts were included, which revealed that animals with AFLD exhibited elevated expression of CYP2E1, decreased enzymatic activity of antioxidant enzymes, and reduced levels of the transcription factor Nrf2, which plays a pivotal role in the synthesis of antioxidant enzymes. Furthermore, animals with AFLD exhibited increased levels of lipid peroxidation markers and carbonylated proteins, collectively contributing to a weakened antioxidant defense and increased oxidative damage. The liver damage in AFLD was supported by significantly higher activity of alanine and aspartate aminotransferase enzymes. Moreover, animals with AFLD had increased levels of triacylglycerol in the serum and liver, likely due to reduced fatty acid metabolism caused by decreased PPAR-α expression, which is responsible for fatty acid oxidation, and increased expression of SREBP-1c, which is involved in fatty acid synthesis. With regard to inflammation, animals with AFLD exhibited elevated levels of pro-inflammatory cytokines, including TNF-a, IL-1β, and IL-6. The heightened oxidative stress, along with inflammation, led to an upregulation of cell death markers, such as caspase-3, and an increased Bax/Bcl-2 ratio. Overall, the findings of the review and meta-analysis indicate that ethanol metabolism reduces important markers of antioxidant defense while increasing inflammatory and apoptotic markers, thereby contributing to the development of AFLD.

Role of ferroptosis in fibrosis: From mechanism to potential therapy

ABSTRACT

Fibrosis, which is a manifestation of the physiological response to injury characterized by excessive accumulation of extracellular matrix components, is a ubiquitous outcome of the repair process. However, in cases of repetitive or severe injury, fibrosis may become dysregulated, leading to a pathological state and organ failure. In recent years, a novel form of regulated cell death, referred to as ferroptosis, has been identified as a possible contributor to fibrosis; it is characterized by iron-mediated lipid peroxidation. It has garnered attention due to the growing body of evidence linking ferroptosis and fibrogenesis, which is believed to be driven by underlying inflammation and immune responses. Despite the increasing interest in the relationship between ferroptosis and fibrosis, a comprehensive understanding of the precise role that ferroptosis plays in the formation of fibrotic tissue remains limited. This review seeks to synthesize previous research related to the topic. We categorized the different direct and indirect mechanisms by which ferroptosis may contribute to fibrosis into three categories: (1) iron overload toxicity; (2) ferroptosis-evoked necroinflammation, with a focus on ferroptosis and macrophage interplay; and (3) ferroptosis-associated pro-fibrotic factors and pathways. Furthermore, the review considers the potential implications of these findings and highlights the utilization of ferroptosis-targeted therapies as a promising strategy for mitigating the progression of fibrosis. In conclusion, novel anti-fibrotic treatments targeting ferroptosis could be an effective treatment for fibrosis.