Ferroptosis in gut pathophysiology: Molecular mechanisms and microbial regulation of iron metabolism and oxidative stress

Gut inflammation contributes to the development of gut motility disorders in part by disrupting the function and survival of enteric neurons through mechanisms that involve oxidative stress. How enteric neurons regulate oxidative stress is still poorly understood. Importantly, how neuron autonomous antioxidant mechanisms contribute to the susceptibility of enteric neurons to oxidative stress in disease is not known. Here, we discover that sirtuin-3 (Sirt3), a key regulator of oxidative stress and mitochondrial metabolism, is expressed by neurons in the enteric nervous system (ENS) of the mouse colon. Given the important role of Sirt3 in the regulation of neuronal oxidative stress in the central nervous system (CNS), we hypothesized that Sirt3 plays an important role in the cell autonomous regulation of oxidative stress by enteric neurons and that a loss of Sirt3 increases neuronal vulnerability during intestinal inflammation. We tested our hypothesis using a combination of traditional immunohistochemistry, oxidative stress measurements and in vivo and ex vivo measures of GI motility in healthy and inflamed wild-type (wt) and Sirt3 null (Sirt3−/−) mice. Our results show that Sirt3 is widely expressed by neurons throughout the myenteric plexus of the mouse colon. However, the deletion of Sirt3 had surprisingly little effect on gut function and susceptibility to inflammation. Likewise, neither the genetic ablation of Sirt3 nor the inhibition of Sirt3 with antagonists had a significant effect on neuronal oxidative stress. Therefore, we conclude that Sirt3 contributes very little to the overall regulation of neuronal oxidative stress in the ENS. The functional relevance of Sirt3 in enteric neurons is still unclear but our data show that it is an unlikely candidate to explain neuronal vulnerability to oxidative stress during inflammation.

Response pathways of superoxide dismutase and catalase under the regulation of triclocarban-triggered oxidative stress in Eisenia foetida: Comprehensive mechanism analysis based on cytotoxicity and binding model

Background/Aims: Large-scale epidemiological studies support a correlation between obesity and breast cancer in postmenopausal women. Circulating leptin levels are increased in obese and it has been suggested to play a significant role in mammary tumor formation and progression. Moreover, regulation of oxidative stress is another important factor in both tumor development and responses to anticancer therapies. The aim of this study was to examine the relationship between oxidative stress and chronic leptin exposure. Methods: We treated MCF-7 breast cancer cells with 100 ng/mL leptin for 10 days and analyzed cell growth, ROS production and oxidative damage, as well as, some of the main antioxidant systems. Furthermore, since the hyperleptinemia has been associated with a worse pathology prognosis, we decided to test the influence of leptin in response to cisplatin anticancer treatment. Results: Leptin signalling increased cell proliferation but reduced ROS production, as well as, oxidative damage. We observed an upregulation of SIRT1 after leptin exposure, a key regulator of stress response and metabolism. Additionally, leptin counteracted cisplatin-induced cytotoxicity in tumor cells, showing a decrease in cell death. Conclusion: Chronic leptin could contribute to the effective regulation of endogenous and treatment-induced oxidative stress, and it contributes to explain in part its proliferative effects.

SGK1 is necessary to FoxO3a negative regulation, oxidative stress and cardiac fibroblast activation induced by TGF-β1

The pathogenesis of canine pyometra is multifactorial, involving hormonal imbalances, aberrant immune responses, and metabolic dysregulation includes lipid metabolism and oxidative stress. This study focuses on lipid metabolism and oxidative stress, revealing the key regulatory role of AMPK and PLIN2 in canine pyometra. Bitches with open cervix pyometra (n:8) and healthy bitches undergoing elective ovariohysterectomy (n:4) were enrolled to the study. In experiment one, the serum and tissue levels of Malondialdehyde (MDA) and Superoxide Dismutase (SOD) activity were assessed. Additionally, uterine histopathological analysis, AMPK and PLIN2 expressions were determined through immunohistochemistry. Furthermore, inflammation, oxidative stress, and lipid metabolism-related factors were evaluated using Western blot analysis. In experiment two, primary cell cultures were prepared from healthy uterine endometrial cells of the dogs in control group. Cultured canine endometrial epithelial cells were treated with lipopolysaccharide (LPS) along with oleic acid (OA) to induce an inflammatory response. Tissue and serum MDA and SOD levels were greater in dogs with pyometra. Accumulated lipid droplets were observed in the uterine tissue of bitches with pyometra. The phosphorylation of AMPK and the expression of PLIN2 significantly increased in the pyometra group. The expression of related lipid synthesis proteins such as ACC1, FASN, SREBP-1c, and PLIN2 was upregulated, while PPARα and PGC1α were downregulated in bitches with pyometra. In experiment two, activation of AMPK and PLIN2 not only restores the expression of PGC1α, but also effectively alleviates inflammation and oxidative stress. The role of lipid metabolism and oxidative stress in canine pyometra is elucidated, thus contributing to the pathogenesis of pyometra in dogs.

Extracellular vesicles are cellular secretory particles that can be used as natural drug delivery carriers. They have successfully delivered drugs including chemotherapeutics, proteins, and genes to treat various diseases. Oxidative stress is an abnormal physiological phenomenon, and it is associated with nearly all diseases. In this short review, we summarize the regulation of EVs on oxidative stress. There are direct effects and indirect effects on the regulation of oxidative stress through EVs. On the one hand, they can deliver antioxidant substances or oxides to recipient cells, directly relieving or aggravating oxidative stress. On the other hand, regulate factors of oxidative stress-related signaling pathways can be delivered to recipient cells by the mediation of EVs, realizing the indirect regulation of oxidative stress. To the best of our knowledge, however, only endogenous drugs have been delivered by EVs to regulate oxidative stress till now. And the heterogeneity of EVs may complicate the regulation of oxidative stress. Therefore, this short review aims to draw more attention to the EVs-based regulation of oxidative stress, and we hope excellent EVs-based delivery carriers that can deliver exogenous drugs to regulate oxidative stress can be exploited.

LCA, a bacterial metabolite, induces ferroptosis and senescence in triple-negative breast cancer.

Obesity is concerning because of the numerous health conditions associated with excess weight. Underlying mechanisms contributing to detrimental health outcomes are oxidative stress and inflammation. Fortunately, regulation of oxidative stress and inflammation is possible via antioxidants consumed through a diet adequate in fruits and vegetables. However, consumption of fruits and vegetables is below recommended amounts. This study evaluated the effectiveness of a nutrition education program and provision of fruits and vegetables on consumption of antioxidants and changes in inflammation and oxidative stress biomarkers. Forty‐seven adults (16 men/31 women; 45.9 ± 11.8 y; BMI 32.7 kg/m2) were randomly assigned to one of three intervention groups: control group received no intervention; education group attended weekly nutrition education lessons; fruit and vegetable group attended weekly nutrition education lessons and received one serving of fruits and two servings of vegetables daily for 10 weeks. Fasting blood draws and consumption of fruits, vegetables, and antioxidants from three‐day food records were assessed. While changes in consumption were minimally associated with improvements in biomarkers of inflammation and oxidative stress, adequate and varied consumption of fruits and vegetables is recommended to aid in regulation of inflammation and oxidative stress. Sources of research support: scholarships, department grant

Introduction Coexistence of diabetes and hypertension exacerbates morbidity of cardiovascular diseases, indicating a synergy/cooperativity between these pathophysiologies. Although multifactorial, hypertension is associated with vasoconstrictor-mediated arterial hyper-construction and remodelling via their cognate G protein-coupled receptors (GPCRs). Signalling via Gs-coupled GPCRs such as the β₂-adrenergic receptors (β₂ARs) opposes the actions of vasoconstrictors by inducing vasodilation and inhibiting vasoconstrictor-stimulated remodelling pathways such as ERK. As elevated glucose is known to affect multiple aspects of cellular physiology, we examined the effects of acute (6-day) glucose exposure on the proteome of rat aortic smooth muscle cells (RASM). Purposes To determine whether glucose affected protein expression by measuring differentially expressed proteins (DEPs) in RASM exposed to high (20 mM) and low (5 mM) glucose concentrations. The study also aimed to investigate the role of ERK-related protein interactions in vascular remodelling. Methods Cellular cultivation and glucose administration. RASM were isolated from male Wistar rats and cultured in Dulbecco's Modified Eagle Medium supplemented with 10% foetal bovine serum under low glucose (5 mM) or high glucose (20 mM) conditions for 6 days. Protein extraction and trypsin digestion for mass spectrometry-based proteomics were conducted prior to analysis, utilising liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for label-free quantification. A bespoke R pipeline utilising the Limma package was employed for statistical analysis and the creation of volcano plots. A string-based network analysis was utilised to show ERK-related signalling proteins. Results A total of 2,317 proteins were found, of which 21 were significantly upregulated under high glucose conditions (p < 0.05, log2FC > 1). RASM were cultured in high glucose showed a distinct DEP compared to those in low glucose media (Figure 1). Enrichment analysis alters targeted pathways, such as MAPK/ERK signalling, oxidative stress, and metabolic regulation (Figure 2). The main hubs of the network were MAPK1 (ERK2) and MAPK3 (ERK1), which linked to important proteins such as Hepatocyte Growth Factor (HGF), Glutathione S-Transferase Mu 1 (GSTM1), Lysine Acetyltransferase 5 (KAT5), and Y-box binding protein 3 (YBX3). These proteins all play a part in ERK-mediated cell growth and vascular remodelling. HGF strongly interacted with MAPK3, confirming its role as an upstream activator of ERK. Conclusions Short-term (6-day) exposure to high glucose (20 mM) induces massive changes in the VSMC proteome, including elevated levels of MAPK/ERK signalling proteins and oxidative stress regulators. The results point to potential molecular alterations that underlie the illness-related dysregulation of vascular physiology and provide avenues for future investigation.Volcano Plot Proteins interaction

Atherosclerosis, a leading contributor to cardiovascular diseases (CVDs), is characterized by foam cell formation driven by excessive lipid accumulation in macrophages and vascular smooth muscle cells. This study elucidates the anti-atherosclerotic potential of AWLNH (P3) and PHDL (P4) peptides by assessing their effects on foam cell formation, lipid metabolism, and oxidative stress regulation. P3 and P4 effectively suppressed intracellular lipid accumulation in RAW264.7 macrophages and human aortic smooth muscle cells (hASMCs), thereby mitigating foam cell formation. Mechanistically, both peptides modulated cholesterol homeostasis by downregulating cholesterol influx mediators, cluster of differentiation 36 (CD36), and class A1 scavenger receptor (SR-A1), while upregulating cholesterol efflux transporters ATP-binding cassette subfamily A member 1 (ABCA1) and ATP-binding cassette subfamily G member 1 (ABCG1). The activation of peroxisome proliferator-activated receptor-gamma (PPAR-γ) and liver X receptor-alpha (LXR-α) further substantiated their role in promoting cholesterol efflux and restoring lipid homeostasis. Additionally, P3 and P4 peptides exhibited potent antioxidative properties by attenuating reactive oxygen species (ROS) generation through activation of the HO-1/Nrf2 signaling axis. HO-1 silencing via siRNA transfection abolished these effects, confirming HO-1-dependent regulation of oxidative stress and lipid metabolism. Collectively, these findings highlight P3 and P4 peptides as promising therapeutic agents for atherosclerosis by concurrently targeting foam cell formation, cholesterol dysregulation, and oxidative stress, warranting further exploration for potential clinical applications.

BackgroundThe Ets-1 proto-oncogene is frequently upregulated in cancer cells, with known involvement in cancer angiogenesis, metastasis, and more recently energy metabolism. In this study we have performed various bioinformatic analyses on existing microarray data to further clarify the role of Ets-1 in ovarian cancer, and validated these results with functional assays.MethodsFunctional pathway analyses were conducted on existing microarray data comparing 2008 and 2008-Ets1 ovarian cancer cells. Methods included over-representation analysis, functional class scoring and pathway topology, and network representations were visualized in Cytoscape. Oxidative stress regulation was examined in ovarian cancer cells by measuring protein expression and enzyme activity of glutathione peroxidases, as well as intracellular reactive oxygen species using dichlorofluorescin fluorescence. A stable Ets-1 knockdown MDA-MB-231 cell line was created using short hairpin RNA, and glycolytic dependence of these cells was measured following treatment with 2-deoxy-D-glucose and Hoechst nuclear staining to determine cell number. High-resolution respirometry was performed to measure changes in basal oxygen flux between MDA-MB-231 cells and MDA-Ets1KD variants.ResultsEnrichments in oxidoreductase activity and various metabolic pathways were observed upon integration of the different analyses, suggesting that Ets-1 is important in their regulation. As oxidative stress is closely associated with these pathways, we functionally validated our observations by showing that Ets-1 overexpression resulted in decreased reactive oxygen species with increased glutathione peroxidase expression and activity, thereby regulating cellular oxidative stress. To extend our findings to another cancer type, we developed an Ets-1 knockdown breast cancer cell model, which displayed decreased glycolytic dependence and increased oxygen consumption following Ets-1 knockdown confirming our earlier findings.ConclusionsCollectively, this study confirms the important role of Ets-1 in the regulation of cancer energy metabolism in ovarian and breast cancers. Furthermore, Ets-1 is a key regulator of oxidative stress in ovarian cancer cells by mediating alterations in glutathione antioxidant capacity.

Objectivep66Shc, a 66 kDa protein isoform encoded by the proto-oncogene SHC, is an essential intracellular redox homeostasis regulatory enzyme that is involved in the regulation of cellular oxidative stress, apoptosis induction and the occurrence of multiple age-related diseases. This study investigated the expression profile and functional characteristics of p66Shc during preimplantation embryo development in sheep.MethodsThe expression pattern of p66Shc during preimplantation embryo development in sheep at the mRNA and protein levels were studied by quantitative real-time polymerase chain reaction (RT-qPCR) and immunofluorescence staining. The effect of p66Shc knockdown on the developmental potential were evaluated by cleavage rate, morula rate and blastocyst rate. The effect of p66Shc deficiency on reactive oxygen species (ROS) production, DNA oxidative damage and the expression of antioxidant enzymes (e.g., catalase and manganese superoxide dismutase [MnSOD]) were also investigated by immunofluorescence staining.ResultsOur results showed that p66Shc mRNA and protein were expressed in all stages of sheep early embryos and that p66Shc mRNA was significantly downregulated in the 4- to 8-cell stage (p<0.05) and significantly upregulated in the morula and blastocyst stages after embryonic genome activation (EGA) (p<0.05). Immunofluorescence staining showed that the p66Shc protein was mainly located in the peripheral region of the blastomere cytoplasm at different stages of preimplantation embryonic development. Notably, serine (Ser36)-phosphorylated p66Shc localized only in the cytoplasm during the 2- to 8-cell stage prior to EGA, while phosphorylated (Ser36) p66Shc localized not only in the cytoplasm but also predominantly in the nucleus after EGA. RNAi-mediated silencing of p66Shc via microinjection of p66Shc siRNA into sheep zygotes resulted in significant decreases in p66Shc mRNA and protein levels (p<0.05). Knockdown of p66Shc resulted in significant declines in the levels of intracellular ROS (p<0.05) and the DNA damage marker 8-hydroxy-2′-deoxyguanosine (p<0.05), markedly increased MnSOD levels (p<0.05) and resulted in a tendency to develop to the morula stage.ConclusionThese results indicate that p66Shc is involved in the metabolic regulation of ROS production and DNA oxidative damage during sheep early embryonic development.

Nonalcoholic fatty liver disease (NAFLD) is a prevalent liver disorder that has emerged as a significant public health concern. This study aimed to investigate the mechanisms by which Y-box binding protein-1 (YB1) knockdown influences lipid metabolism and oxidative stress in palmitic acid (PA)-induced NAFLD LO2 cells. The expression of YB1 was analyzed using the GSE89632 dataset from the Gene Expression Omnibus (GEO) database. RNA sequencing was performed, followed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, and protein-protein interaction (PPI) network analyses to identify differentially expressed genes (DEGs). Quantitative real-time PCR (QRT-PCR), Western blotting, flow cytometry, and various biochemical assays were used to evaluate gene expression, lipid accumulation, and oxidative stress. Our results demonstrated that YB1 is highly expressed in NAFLD. RNA sequencing revealed 798 DEGs between the shCtrl and shYB1 groups, with 190 genes upregulated and 608 genes downregulated. Notably, we observed an increase in Inhibin beta E (INHBE) expression, while EGR1, GDF15, NUPR1, and FOSB were decreased in NAFLD LO2 cells. YB1 knockdown, particularly when combined with INHBE suppression, significantly enhanced cell viability, improved lipid metabolism, and reduced reactive oxygen species (ROS) accumulation and malondialdehyde (MDA) content. The downstream mechanism was primarily associated with TNF-β signaling. Specifically, we observed decreased levels of TGF-β1, p-Smad2, and p-Smad3 following YB1 and INHBE knockdown. Furthermore, INHBE overexpression reversed the beneficial effects induced by YB1 knockdown. In conclusion, YB1 knockdown improves lipid metabolism and reduces oxidative stress in NAFLD LO2 cells, largely through the INHBE/TNF-β signaling pathway. These findings provide valuable insights into novel therapeutic strategies for managing NAFLD.

Introduction: Molecular chaperone and co-chaperone play important roles in maintaining cardiac function by regulating cellular proteostasis and reducing oxidative stress during hypertrophy. Bcl2 binding proteinBAG5 belongs to Bcl-2 associated anthanogene (BAG) family and acts as a co-chaperone to HSP70. Genetic mutation of BAG5 induces dilated cardiomyopathy and arrhythmia. However, the molecular mechanism of BAG5 in heart function is unclear. In this study, we explore the regulatory role of BAG5 in heart function. Hypothesis: We hypothesized that BAG5 is an important Co-chaperone of cardiomyocytes and regulates heart function through the regulation of cellular proteostasis and oxidative stress. Method: We have generated adenovirus to overexpress and knockdown the BAG5 protein in cardiomyocytes. Additionally, we have generated BAG5 knockout mice to test the effect of BAG5 deficiency on cardiac function. Further, we have conducted a proteomics study to explore the role of BAG5 in heart function. Additionally, we tested the role of BAG5 in isoproterenol-induced cardiac hypertrophy. Results: Our results show that deficiency of BAG5 induces cellular hypertrophy and induction of cellular autophagy. Cardiac function analysis by echocardiography shows that the knockdown of BAG5 compromises heart function. Further, a protein interaction study shows that BAG5 participates in several critical heart signaling, including mitochondrial oxphos and glutathione-mediated regulation of oxidative stress. Additionally, we found that the knockdown of BAG5 worsens heart function during isoproterenol treatment. Conclusion: Our study shows a novel function of BAG5 and BAG5 can be exploited in treating cardiac hypertrophy and reducing oxidative stress.

Chk2 deletion rescues bone loss and cellular senescence induced by Bmi1 deficiency via regulation of Cyp1a1.