Farnesoid X receptor activation by bile acids suppresses lipid peroxidation and ferroptosis

OTUD4 inhibits ferroptosis by stabilizing GPX4 and suppressing autophagic degradation to promote tumor progression

Ferroptosis, a regulated cell demise predicated on iron metabolism and lipid peroxidation, has increasingly become a focal point in oncological therapies. Nonetheless, its governance, particularly the role of deubiquitination, is not fully delineated. This investigation concentrates on the deubiquitinase OTUD4, scrutinizing its functional and molecular implications in ferroptosis within tumor cells. By engineering OTUD4 knockout cell lines via CRISPR-Cas9, we observed that these cells exhibit heightened sensitivity to ferroptosis inducers, augmenting ferroptotic cell death and robustly diminishing tumor growth both in vitro and in vivo. Mechanistically, OTUD4 not only sustains protein stability by directly deubiquitinating GPX4 but also impedes its degradation via RHEB-mediated autophagy, collectively stalling the ferroptosis pathway. In vivo assays substantiate that OTUD4 deletion, when combined with regorafenib, drastically reduces tumor proliferation, showcasing potent synergistic antitumor activity. This study pioneers the revelation of OTUD4's bifunctional role in modulating ferroptosis through deubiquitination and autophagy, underscoring its potential as a therapeutic target in oncology.

Bioactive natural alkaloid 6-Methoxydihydrosanguinarine exerts anti-tumor effects in hepatocellular carcinoma cells via ferroptosis

Introduction

Ferroptosis is a form of regulated cell death driven by the accumulation of iron-dependent lipid peroxides, and ferroptosis-mediated cancer therapy has gained considerable attention. Despite emerging evidence that ferroptosis induction effectively suppresses hepatocellular carcinoma (HCC) progression and enhances chemosensitivity, the development of resistance to ferroptosis-targeting therapies remains a critical challenge. Natural active compounds have great potential in cancer treatment.

Methods

The impact of 6-ME on the cell viability of HCC cells was assessed using the Cell Counting Kit-8 (CCK-8) assay and colony formation assay. Furthermore, cellular morphology of HCC cells was visualized under inverted fluorescence microscopy. Intracellular reactive oxygen species (ROS) and lipid peroxidation levels were quantified using fluorescence probes and determined by flow cytometry analysis. The expression of ferroptosis-related proteins and genes was determined via Western blot and quantitative real-time PCR analyses.

Results

Here, we demonstrate that 6-Methoxydihydrosanguinarine (6-ME), an alkaloid from Macleaya cordata, exerts anti-tumor functions in HCC cells via ferroptosis. Stimulation with 6-ME induces intracellular ROS production, cell growth inhibition, and cell death in HCC cells, and these effects can be weakened by the ROS scavenger GSH or NAC and ferroptosis inhibitors deferoxamine mesylate (DFO) or ferrostatin-1 (Fer-1). Mechanistically, 6-ME downregulates the expression of the key ferroptosis defense enzyme GPX4 at the transcriptional level, leading to excessive lipid peroxidation and ferroptosis in HCC cells. Importantly, low concentrations of 6-ME also enhanced the ferroptosis sensitivity induced by RSL3 and IKE in HCC cells.

Conclusion

These findings reveal that the natural product 6-ME exerts anti-tumor functions in HCC cells via ferroptosis and underscore the potential of 6-ME administered alone or in combination with canonical ferroptosis inducers for the treatment of HCC patients.

Ferroptosis as a key player in the pathogenesis and intervention therapy in liver injury: focusing on drug-induced hepatotoxicity

Globally, drug-induced hepatotoxicity or drug-induced liver injury (DILI) is a serious clinical concern. Knowing the processes and patterns of cell death is essential for finding new therapeutic targets since there are not many alternatives to therapy for severe liver lesions. Excessive lipid peroxidation is a hallmark of ferroptosis, an iron-reliant non-apoptotic cell death linked to various liver pathologies. When iron is pathogenic, concomitant inflammation may exacerbate iron-mediated liver injury, and the hepatocyte necrosis that results is a key element in the fibrogenic response. The idea that dysregulated metabolic pathways and compromised iron homeostasis contribute to the development of liver injury by ferroptosis is being supported by new data. Various ferroptosis-linked genes and pathways have been linked to liver injury, although the molecular processes behind ferroptosis's pathogenicity are not well known. Here, we delve into the features of ferroptosis, the processes governing ferroptosis, and our current knowledge of iron metabolism. We also provide an overview of ferroptosis's involvement in the pathophysiology of liver injury, particularly DILI. Lastly, the therapeutic possibilities of ferroptosis targeting for liver injury management have been provided. Natural products, nanoparticles (NPs), mesenchymal stem cell (MSC), and their exosomes have attracted increasing attention among such therapeutics.

The metabolites of gut microbiota: their role in ferroptosis in inflammatory bowel disease

Inflammatory bowel disease (IBD) includes chronic inflammatory conditions, such as Crohn's disease and ulcerative colitis, characterized by impaired function of the intestinal mucosal epithelial barrier. In recent years, ferroptosis, a novel form of cell death, has been confirmed to be involved in the pathological process of IBD and is related to various pathological changes, such as oxidative stress and inflammation. Recent studies have further revealed the complex interactions between the microbiome and ferroptosis, indicating that ferroptosis is an important target for the regulation of IBD by the gut microbiota and its metabolites. This article reviews the significant roles of gut microbial metabolites, such as short-chain fatty acids, tryptophan, and bile acids, in ferroptosis in IBD. These metabolites participate in the regulation of ferroptosis by influencing the intestinal microenvironment, modulating immune responses, and altering oxidative stress levels, thereby exerting an impact on the pathological development of IBD. Treatments based on the gut microbiota for IBD are gradually becoming a research hotspot. Finally, we discuss the potential of current therapeutic approaches, including antibiotics, probiotics, prebiotics, and fecal microbiota transplantation, in modulating the gut microbiota, affecting ferroptosis, and improving IBD symptoms. With a deeper understanding of the interaction mechanisms between the gut microbiota and ferroptosis, it is expected that more precise and effective treatment strategies for IBD will be developed in the future.

Pharmacological effects of bile acids on polycystic ovary syndrome via the regulation of chemerin

BACKGROUND

Polycystic ovary syndrome (PCOS) poses significant health risks for women of reproductive age, and conventional treatments typically involve anti-hormonal interventions or surgical procedures, which often lead to lifelong medication cycles and potential side effects. Bile acids have been applied in the treatment of PCOS-related conditions, including obesity and type 2 diabetes. This study aimed to investigate the effects of bile acids on a PCOS rat model and explore the underlying mechanisms involved.

METHODS

Morphological index evaluation, histopathological examination, and hormonal profiling were employed to assess the therapeutic effects of eight bile acids. A targeted proteomics was utilized to characterize and quantify highly homologous chemerin isoforms in rat serum. Network pharmacology analysis was conducted to identify potential targets and molecular mechanisms involved. Molecular docking was performed to evaluate the affinity between bile acids and farnesoid X receptor (FXR).

RESULTS

Five of the eight bile acids markedly restored morphological indices, histopathological manifestations, hormonal imbalances, and chemerin isoform dysregulation. Notably, the therapeutic effects of TDCA and GUDCA on PCOS were reported for the first time. As the severity of the disease decreased, chemerin-157S was negatively correlated with progesterone (P4), estradiol (E2), antral follicles, and corpus luteum, respectively. Several chemerin-associated pathways have been identified via network pharmacology analysis. Additionally, a 7β-hydroxy group carried on the steroid skeleton of bile acids has been found to exhibit positive therapeutic efficacy in PCOS.

CONCLUSIONS

Downregulating chemerin levels via specific bile acids may be a promising therapeutic strategy for PCOS patients.

Gut microbial metabolism in ferroptosis and colorectal cancer

Ferroptosis is programmed cell death induced by iron-driven lipid peroxidation. Numerous studies have shown that ferroptosis is implicated in the progression of colorectal cancer (CRC) and has emerged as a promising strategy to combat therapy-resistant CRC. While the intrinsic antiferroptotic and proferroptotic pathways in CRC cells have been well characterized, extrinsic metabolism pathways regulating ferroptosis in CRC pathogenesis remain less understood. Emerging evidence shows that gut microbial metabolism is tightly correlated with the progression of CRC. This review provides an overview of gut microbial metabolism and discusses how these metabolites derived from intestinal microflora contribute to cancer plasticity through ferroptosis. Targeting gut microbe-mediated ferroptosis is a potential approach for CRC treatment.

Hsa_circ_0001944 Regulates FXR/TLR4 Pathway and Ferroptosis to Alleviate Nickel Oxide Nanoparticles-Induced Collagen Formation in LX-2 Cells

Nickel oxide nanoparticles (NiONPs) can induce liver fibrosis, and their mechanism may be related to non-coding RNA, nuclear receptor signal transduction and ferroptosis, but the regulatory relationship between them is not clear. In this study, we aimed to investigate the role of hsa_circ_0001944 in regulating the Farnesol X receptor (FXR)/Toll-like receptor 4 (TLR4) pathway and ferroptosis in NiONPs-induced collagen deposition. We observed decreased FXR expression, increased TLR4 expression and alterations in ferroptosis features in both the rat liver fibrosis and the LX-2 cell collagen deposition model. To investigate the regulatory relationship among FXR, TLR4 and ferroptosis, we treated LX-2 cells with FXR agonist (GW4064), TLR4 inhibitor (TAK-242) and ferroptosis agonist (Erastin) combined with NiONPs. The results showed that TAK-242 alleviated collagen deposition by increasing ferroptosis features. Furthermore, GW4064 reduced the expression of TLR4, increased the ferroptosis features and alleviated collagen deposition. The results indicated that FXR inhibited the expression of TLR4 and enhanced the ferroptosis features, which were involved in the process of collagen deposition in LX-2 cells induced by NiONPs. Subsequently, we predicted that hsa_circ_0001944 might regulate FXR through bioinformatics analysis, and found NiONPs reduced the expression of hsa_circ_0001944 in LX-2 cells. Overexpression of hsa_circ_0001944 increased FXR level, reduced TLR4 level, increased the ferroptosis features and alleviated collagen deposition in LX-2 cells. In summary, we demonstrated that hsa_circ_0001944 regulates the FXR/TLR4 pathway and ferroptosis alleviate collagen formation induced by NiONPs.

Bile acid receptor FXR promotes intestinal epithelial ferroptosis and subsequent ILC3 dysfunction in neonatal necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a common pediatric emergency primarily afflicting preterm infants, yet its mechanisms remain to be fully understood. Here, we report that plasma fibroblast growth factor (FGF)19, a target of farnesoid X receptor (FXR), was positively correlated with the clinical parameters of NEC. NEC patients and the NEC murine model displayed abundant FXR in intestinal epithelial cells (IECs), which was restricted by microbiota-derived short-chain fatty acids (SCFAs) under homeostasis. Genetic deficiency of FXR in IECs caused remission of NEC. Mechanistically, FXR facilitated ferroptosis of IECs via targeting acyl-coenzyme A synthetase long-chain family member 4 (Acsl4). Lipid peroxides released by ferroptotic IECs suppressed interleukin (IL)-22 secretion from type 3 innate lymphoid cells (ILC3s), thereby exacerbating NEC. Intestinal FXR antagonist, ACSL4 inhibitor, and ferroptosis inhibitor ameliorated murine NEC. Furthermore, the elevated lipid peroxides in NEC patients were positively correlated with FGF19 and disease parameters. These observations demonstrate the therapeutic value of targeting intestinal FXR and ferroptosis in NEC treatment.

FXR activation reduces the formation of macrophage foam cells and atherosclerotic plaque, possibly by down regulating hepatic lipase in macrophages

Macrophages are the most important immune cells affecting the formation of atherosclerotic plaque. Nevertheless, the mechanisms that promote formation of foamy macrophages during atherogenesis remain poorly understood. This study explored the effects of Farnesoid X receptor (FXR) and hepatic lipase (HL, encoded by LIPC) on atherogenesis, particularly in foamy macrophage formation. A luciferase reporter assay indicated that FXR could bind to the LIPC promoter and inhibit LIPC transcription. FXR agonist GW4064 decreased HL expression, foam cell formation, and increased the expression of FXR downstream genes and polarization to M2 in ox-LDL-induced THP-1 and U937 foam cells. In addition, GW4064 exerted anti-atherosclerotic effects in ApoE-/- mice, manifested as decreased serum cholesterol and triglyceride levels, and alleviated atherosclerotic plaque formation. Collectively, FXR exerted anti-atherosclerotic effects, possibly by negatively regulating HL expression in macrophages.

Explore the mechanism of yishenjiangya formula in the treatment of senile hypertension based on multi-omics technology

ETHNOPHARMACOLOGICAL RELEVANCE

The Yishenjiangya formula (YSJ) is a traditional Chinese medicine (TCM) primarily composed of qi-tonifying components. This classic formula is commonly utilized to treat kidney qi deficiency in elderly patients with hypertension. According to TCM, maintaining a balance between qi and blood is crucial for stable blood pressure. Kidney qi deficiency can disrupt this balance, altering fluid shear force and, ultimately, leading to hypertension, particularly in elderly populations. Despite YSJ's efficacy in treating hypertension, its specific anti-hypertensive mechanisms remain unclear.

AIM OF THE STUDY

YSJ is commonly prescribed for elderly patients with hypertension. Earlier metabolomics studies demonstrated that YSJ exerts antihypertensive effects by influencing four key pathways: linoleic acid metabolism, glycerol phospholipid metabolism, arginine and proline metabolism, and steroid hormone biosynthesis. This study aims to combine metabolomic and proteomic analyses to thoroughly understand the molecular biological mechanisms responsible for YSJ's anti-hypertensive properties.

METHODS

Ultra-Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS) metabolomics, combined with Label-Free Quantitation (LFQ) proteomics, was employed to analyze serum samples from elderly individuals with and without hypertension pre- and post-YSJ intervention. Serum levels of candidate proteins were assessed using enzyme-linked immunosorbent assay, and receiver operating characteristic curves were used to evaluate the diagnostic performance of the target proteins.

RESULTS

Eight differentially expressed metabolites and three differentially expressed proteins were identified as potential therapeutic targets of YSJ. These substances are primarily involved in unsaturated fatty acid metabolism, fluid shear stress and atherosclerosis pathway, primary bile acid biosynthesis, proline metabolism, apoptosis, and endoplasmic reticulum stress. YSJ exerts its therapeutic effects on hypertension in the elderly by modulating these pathways.

CONCLUSIONS

YSJ effectively treats senile hypertension. By analyzing the correlation between therapeutic targets and pathways, YSJ's anti-hypertensive effect was achieved by inhibiting lipid peroxidation and matrix degeneration. Combining metabolomics and proteomics provides an effective method for uncovering YSJ's anti-hypertensive mechanisms.

Hyodeoxycholic acid inhibits colorectal cancer proliferation through the FXR/EREG/EGFR axis

Background

The high morbidity and mortality rates of colorectal cancer (CRC) have been a public health concern globally, and the search for additional therapeutic options is imminent. Hyodeoxycholic acid (HDCA) has been receiving attention in recent years and has demonstrated potent efficacy in several diseases. Nonetheless, the antitumor effects and molecular pathways of HDCA in CRC remain largely unexplored.

Methods

In this study, we investigated how HDCA influences the growth potential of CRC cells using techniques such as flow cytometry, Edu assay, CCK-8, colony formation assay, Western blot analysis, and animal experiments.

Results

It was found that HDCA treatment of CRC cells was able to significantly inhibit the proliferative capacity of the cells. Furthermore, it was discovered that HDCA primarily stimulated Farnesoid X Receptor (FXR) rather than Takeda G protein coupled receptor 5 (TGR5) to suppress CRC growth. It was also confirmed that HDCA inhibited the Epiregulin (EREG)/Epidermal Growth Factor Receptor (EGFR) pathway by activating FXR, and a negative correlation between FXR and EREG was analyzed in CRC tissue samples. Finally, in vivo animal studies confirmed that HDCA inhibited CRC proliferation without hepatotoxicity.

Conclusion

Our findings indicate that HDCA suppresses the EREG/EGFR signaling route by activating FXR, thereby hindering the growth of CRC cells and demonstrating a tumor-inhibiting effect in CRC. This study may provide a new therapeutic strategy to improve the prognosis of CRC.

Sterols in ferroptosis: from molecular mechanisms to therapeutic strategies

Ferroptosis, a novel cell death mode driven by iron-dependent phospholipid (PL) peroxidation, has emerged as a promising therapeutic strategy for the treatments of cancer, cardiovascular diseases, and ischemic-reperfusion injury (IRI). PL peroxidation, the key process of ferroptosis, requires polyunsaturated fatty acid (PUFA)-containing PLs (PL-PUFAs) as substrates, undergoing a chain reaction with iron and oxygen. Cells prevent ferroptosis by maintaining a homeostatic equilibrium among substrates, processes, and detoxification of PL peroxidation. Sterols, lipids abundant in cell membranes, directly participate in PL peroxidation and influence ferroptosis sensitivity. Sterol metabolism also plays a key role in ferroptosis, and targeting sterols presents significant potential for treating numerous ferroptosis-associated disorders. This review elucidates the fundamental mechanisms of ferroptosis, emphasizing how sterols modulate this process and their therapeutic potential.

Unraveling Ferroptosis: A New Frontier in Combating Renal Fibrosis and CKD Progression

Chronic kidney disease (CKD) is a global health concern caused by conditions such as hypertension, diabetes, hyperlipidemia, and chronic nephritis, leading to structural and functional kidney injury. Kidney fibrosis is a common outcome of CKD progression, with abnormal fatty acid oxidation (FAO) disrupting renal energy homeostasis and leading to functional impairments. This results in maladaptive repair mechanisms and the secretion of profibrotic factors, and exacerbates renal fibrosis. Understanding the molecular mechanisms of renal fibrosis is crucial for delaying CKD progression. Ferroptosis is a type of discovered an iron-dependent lipid peroxidation-regulated cell death. Notably, Ferroptosis contributes to tissue and organ fibrosis, which is correlated with the degree of renal fibrosis. This study aims to clarify the complex mechanisms of ferroptosis in renal parenchymal cells and explore how ferroptosis intervention may help alleviate renal fibrosis, particularly by addressing the gap in CKD mechanisms related to abnormal lipid metabolism under the ferroptosis context. The goal is to provide a new theoretical basis for clinically delaying CKD progression.

ACSL3 is an unfavorable prognostic marker in cholangiocarcinoma patients and confers ferroptosis resistance in cholangiocarcinoma cells

Cholangiocarcinoma (CCA) is a bile duct malignancy. Our previous comprehensive analysis showed that ferroptosis-related genes can stratify CCA patients into low-risk and high-risk groups based on survival time. Here, we explored the role of ferroptosis in CCA by analyzing mRNA expression in CCA patients from public databases. We identified acyl-CoA synthetase long chain family member 3 (ACSL3) as a potential ferroptosis suppressor in high-risk CCA patients. Using a panel of CCA cell lines, we confirmed ACSL3 upregulation in CCA cell lines associated with high-risk CCA, correlating this with resistance to the ferroptosis inducer RSL3. Lipidomic analysis revealed increased monounsaturated fatty acid (MUFA)-containing phospholipids in resistant cell lines. ACSL3 silencing sensitized these cells to RSL3. Resistance to ferroptosis was also dependent on exogenous MUFAs and was enhanced by lipid droplet biogenesis inhibition. These findings highlight ACSL3 as a promising target for therapeutic strategies aimed at overcoming ferroptosis resistance in CCA.

Pharmacological Mechanisms of Bile Acids Targeting the Farnesoid X Receptor

Bile acids (BAs), a category of amphiphilic metabolites synthesized by liver cells and released into the intestine via the bile duct, serve a vital role in the emulsification of ingested fats during the digestive process. Beyond their conventional emulsifying function, BAs, with their diverse structures, also act as significant hormones within the body. They are pivotal in facilitating nutrient absorption by interacting with the farnesoid X receptor (FXR), and they serve as key regulators of lipid and glucose metabolism, as well as immune system balance. Consequently, BAs contribute to the metabolism of glucose and lipids, enhance the digestion and absorption of lipids, and maintain the equilibrium of the bile pool. Their actions are instrumental in addressing obesity, managing cholestasis, and treating diabetes, and are involved in the onset and progression of cancer. This paper presents an updated systematic review of the pharmacological mechanisms by which BAs target the FXR, incorporating recent findings and discussing their signaling pathways in the context of novel research, including their distinct roles in various disease states and populations. The aim is to provide a theoretical foundation for the continued research and clinical application of BAs.

Essentiality of SLC7A11-mediated nonessential amino acids in MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) remains a rapidly growing global health burden. Here, we report that the nonessential amino acid (NEAA) transporter SLC7A11 plays a key role in MASLD. In patients with MASLD, we found high expression levels of SLC7A11 that were correlated directly with clinical grade. Using both loss-of-function and gain-of-function genetic models, we found that Slc7a11 deficiency accelerated MASLD progression via classic cystine/cysteine deficiency-induced ferroptosis, while serine deficiency and a resulting impairment in de novo cysteine production were attributed to ferroptosis-induced MASLD progression in mice overexpressing hepatic Slc7a11. Consistent with these findings, we found that both serine supplementation and blocking ferroptosis significantly alleviated MASLD, and the serum serine/glutamate ratio was significantly lower in these preclinical disease models, suggesting that it might serve as a prognostic biomarker for MASLD in patients. These findings indicate that defects in NEAA metabolism are involved in the progression of MASLD and that serine deficiency-triggered ferroptosis may provide a therapeutic target for its treatment.

Seratrodast inhibits ferroptosis by suppressing lipid peroxidation

Ferroptosis is a regulated and non-apoptotic form of cell death mediated by iron-dependent peroxidation of polyunsaturated fatty acyl tails in phospholipids. Research of the past years has shed light on the occurrence of ferroptosis in organ injury and degenerative diseases of the brain, kidney, heart, and other tissues. Hence, ferroptosis inhibition may prove therapeutically beneficial to treat distinct diseases. In this study, we explored the ferroptosis-modulating activity of seratrodast, an inhibitor of thromboxane A2 (TXA2) receptor, which is approved in some countries for the treatment of asthma. Interestingly, seratrodast suppressed ferroptosis, but not apoptosis and necroptosis; thus, demonstrating selective anti-ferroptotic activity. While seratrodast itself does not inhibit lipid peroxidation, it exhibits potent radical-trapping antioxidant activity upon reduction to its corresponding hydroquinone form-analogously to ubiquinone and vitamin K. Importantly, seratrodast ameliorated the severity of renal ischemia-reperfusion injury in mice. Together, this study provides a drug repurposing case, where seratrodast-a marketed drug-can undergo fast-forward preclinical/clinical development for the inhibition of ferroptosis in distinct degenerative diseases.

SAP130 mediates crosstalk between hepatocyte ferroptosis and M1 macrophage polarization in PFOS-induced hepatotoxicity

Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant widely utilized in industrial manufacturing and daily life, leading to significant environmental accumulation and various public health issues. This study aims to characterize spliceosome-associated protein 130 (SAP130) as a key mediator of crosstalk between hepatocytes and macrophages, elucidating its role in PFOS-induced liver inflammation. The data demonstrate that PFOS exposure induces ferroptosis in mouse liver and AML12 cells. During ferroptosis, SAP130 is released from injured hepatocytes into the microenvironment, binding to macrophage-inducible C-type lectin (Mincle) and activating the Mincle/Syk signaling pathway in macrophages, ultimately promoting M1 polarization and exacerbating liver injury. Treatment with the ferroptosis inhibitor Ferrostatin-1 reduces SAP130 release, inhibits Mincle/Syk signaling activation, and mitigates inflammatory response. Furthermore, siSAP130 suppresses the activation of the Mincle signaling pathway and M1 polarization in BMDM cells. Conversely, treatment with the ferroptosis agonist Erastin enhances paracrine secretion of SAP130 and exacerbates inflammation. These findings emphasize the significance of hepatocyte-macrophage crosstalk as a critical pathway for PFOS-induced liver injury in mice while highlighting SAP130 as a pivotal regulator of ferroptosis and inflammation, thereby elucidating the potential mechanism of PFOS-induced liver injury.

Insights into the pathogenesis of gestational and hepatic diseases: the impact of ferroptosis

Ferroptosis, a distinct form of non-apoptotic cell death characterized by iron dependency and lipid peroxidation, is increasingly linked to various pathological conditions in pregnancy and liver diseases. It plays a critical role throughout pregnancy, influencing processes such as embryogenesis, implantation, and the maintenance of gestation. A growing body of evidence indicates that disruptions in these processes can precipitate pregnancy-related disorders, including pre-eclampsia (PE), gestational diabetes mellitus (GDM), and intrahepatic cholestasis of pregnancy (ICP). Notably, while ICP is primarily associated with elevated maternal serum bile acid levels, its precise etiology remains elusive. Oxidative stress induced by bile acid accumulation is believed to be a significant factor in ICP pathogenesis. Similarly, the liver's susceptibility to oxidative damage underscores the importance of lipid metabolism dysregulation and impaired iron homeostasis in the progression of liver diseases such as alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), cholestatic liver injury, autoimmune hepatitis (AIH), acute liver injury, viral hepatitis, liver fibrosis, and hepatocellular carcinoma (HCC). This review discusses the shared signaling mechanisms of ferroptosis in gestational and hepatic diseases, and explores recent advances in understanding the mechanisms of ferroptosis and its potential role in the pathogenesis of gestational and hepatic disorders, with the aim of identifying viable therapeutic targets.

Tellurium-Doped Bioactive Glass Induces Ferroptosis in Osteosarcoma Cells Regardless of FSP1

Human osteosarcoma (OS) is a rare tumor predominantly affecting long bones and characterized by a poor prognosis. Currently, the first line of intervention consists of the surgical resection of primary tumors combined with radiotherapy and chemotherapy, with a profound impact on the patient's life. Since the surgical removal of OS frequently results in a large resection of bones, the use of biomaterials to sustain the stability of the remaining tissue and to stimulate bone regeneration is challenging. Moreover, residual neoplastic cells might be responsible for tumor recurrence. Here, we explored the potential of tellurium-ion-doped bioactive glass as a novel therapeutic intervention to both eradicate residual malignant cells and promote bone regeneration. Bioactive glass (BAG) has been extensively studied and employed in the field of regenerative medicine due to its osseointegration properties and ability to improve bone tissue regeneration. We found that the incorporation of tellurium (Te) in BAG selectively kills OS cells through ferroptosis while preserving the viability of hBMSCs and stimulating their osteodifferentiation. However, the mechanism of Te toxicity is still unclear: (i) Te-BAG generates lipid-ROS through LOXs activity but not iron overload; (ii) Te-dependent ferroptosis is mediated by GPX4 down-regulation; and (iii) the anti-ferroptotic activity of FSP1 is abrogated, whose expression confers the resistance of OS to the canonical induction of ferroptosis. Overall, our data show that Te-doped bioglass could represent an interesting biomaterial with both pro-ferroptotic activity towards residual cancer cells and pro-osteoregenerative activity.

Targeting ACSLs to modulate ferroptosis and cancer immunity

Five acyl-CoA synthetase long-chain family members (ACSLs) are responsible for catalyzing diverse long-chain fatty acids (LCFAs) into LCFA-acyl-coenzyme A (CoA) for their subsequent metabolism, including fatty acid oxidation (FAO), lipid synthesis, and protein acylation. In this review, we focus on ACSLs and their LCFA substrates and introduce their involvement in regulation of cancer proliferation, metastasis, and therapeutic resistance. Along with the recognition of the decisive role of ACSL4 in ferroptosis - an immunogenic cell death (ICD) initiated by lipid peroxidation - we review the functions of ACSLs on regulating ferroptosis sensitivity. Last, we discuss the current understanding of ACSL on the antitumor immune response. We emphasize the necessity to explore the functions of immune cells expressing ACSLs for developing novel strategies to augment immunotherapy by targeting ACSL.

Taurolithocholic acid protects against viral haemorrhagic fever via inhibition of ferroptosis

Bile acids are microbial metabolites that can impact infection of enteric and hepatitis viruses, but their functions during systemic viral infection remain unclear. Here we show that elevated levels of the secondary bile acid taurolithocholic acid (TLCA) are associated with reduced fatality rates and suppressed viraemia in patients infected with severe fever with thrombocytopenia syndrome virus (SFTSV), an emerging tick-borne haemorrhagic fever virus. TLCA inhibits viral replication and mitigates host inflammation during SFTSV infection in vitro, and indirectly suppresses SFTSV-mediated induction of ferroptosis by upregulating fatty acid desaturase 2 via the TGR5-PI3K/AKT-SREBP2 axis. High iron and ferritin serum levels during early infection were correlated with decreased TLCA levels and fatal outcomes in SFTSV-infected patients, indicating potential biomarkers. Furthermore, treatment with either ferroptosis inhibitors or TLCA protected mice from lethal SFTSV infection. Our findings highlight the therapeutic potential of bile acids to treat haemorrhagic fever viral infection.

Comparative analysis of bile acid composition and metabolism in the liver of Bufo gargarizans aquatic larvae and terrestrial adults

Bile acids are crucial for lipid metabolism and their composition and metabolism differ among species. However, there have been no data on the differences in the composition and metabolism of bile acids between aquatic larvae and terrestrial adults of amphibians. This study explored the differences in composition and metabolism of bile acid between Bufo gargarizans larvae and adults. The results demonstrated that adult liver had a lower total bile acid level and a higher conjugated/total bile acid ratio than larval liver. Meanwhile, histological analysis revealed that the larvae showed a larger cross-sectional area of bile canaliculi lumen compared with the adults. The transcriptomic analysis showed that B. gargarizans larvae synthesized bile acids through both the alternative and the 24-hydroxylase pathway, while adults only synthesized bile acids through the 24-hydroxylase pathway. Moreover, bile acid regulator-related genes FXR and RXRα were highly expressed in adult, whereas genes involved in bile acid synthesis (CYP27A1 and CYP46A1) were highly expressed in larvae. The present study will provide valuable insights into understanding metabolic disorders and exploring novel bile acid-based therapeutics.

Galangin attenuates chlorpyrifos-induced kidney injury by mitigating oxidative stress and inflammation and upregulating Nrf2 and farnesoid-X-receptor in rats

Chlorpyrifos (CPF) is a highly toxic commonly used pesticide and can seriously harm human health. This study assessed the potential of galangin (GAL), an antioxidant flavonoid, to attenuate oxidative stress, inflammation and kidney injury caused by CPF, emphasizing the role of farnesoid-x-receptor (FXR) and Nrf2. Rats were supplemented with CPF and GAL for 28 days. CPF increased serum creatinine, urea and Kim-1, provoked several tissue alterations, and increased kidney ROS, malondialdehyde (MDA), NF-κB p65, TNF-α, iNOS, and caspase-3. GAL effectively ameliorated serum kidney injury markers, ROS, MDA, and TNF-α, suppressed NF-κB p65, iNOS, and caspase-3, and enhanced antioxidants. GAL suppressed Keap1 and upregulated FXR, Nrf2, HO-1 and NQO-1 in CPF-administered rats. GAL exhibited binding affinity with Keap1, FXR, caspase-3, iNOS, HO-1, and NF-κB. In conclusion, GAL is effective in preventing CPF nephrotoxicity by attenuating oxidative stress and inflammation. This protection is linked to upregulation of antioxidants, Nrf2/HO-1 signaling and FXR.

Suppression of ferroptosis by vitamin A or radical-trapping antioxidants is essential for neuronal development

The development of functional neurons is a complex orchestration of multiple signaling pathways controlling cell proliferation and differentiation. Because the balance of antioxidants is important for neuronal survival and development, we hypothesized that ferroptosis must be suppressed to gain neurons. We find that removal of antioxidants diminishes neuronal development and laminar organization of cortical organoids, which is fully restored when ferroptosis is inhibited by ferrostatin-1 or when neuronal differentiation occurs in the presence of vitamin A. Furthermore, iron-overload-induced developmental growth defects in C. elegans are ameliorated by vitamin E and A. We determine that all-trans retinoic acid activates the Retinoic Acid Receptor, which orchestrates the expression of anti-ferroptotic genes. In contrast, retinal and retinol show radical-trapping antioxidant activity. Together, our study reveals an unexpected function of vitamin A in coordinating the expression of essential cellular gatekeepers of ferroptosis, and demonstrates that suppression of ferroptosis by radical-trapping antioxidants or by vitamin A is required to obtain mature neurons and proper laminar organization in cortical organoids.

Regulation of gut microbiota on immune cell ferroptosis: A novel insight for immunotherapy against tumor

Gut microbiota contributes to the homeostasis of immune system and is related to various diseases such as tumorigenesis. Ferroptosis, a new type of cell death, is also involved in the disease pathogenesis. Recent studies have found the correlations of gut microbiota mediated ferroptosis and immune cell death. Gut microbiota derived immunosuppressive metabolites, which can promote differentiation and function of immune cells, tend to inhibit ferroptosis through their receptors, whereas inflammatory metabolites from gut microbiota also affect the differentiation and function of immune cells and their ferroptosis. Thus, it is possible for gut microbiota to regulate immune cell ferroptosis. Indeed, gut microbiota metabolite receptor aryl hydrocarbon receptor (AhR) can affect ferroptosis of intestinal intraepithelial lymphocytes, leading to disease pathogenesis. Since immune cell ferroptosis in tumor microenvironment (TME) affects the occurrence and development of tumor, the modulation of gut microbiota in these cell ferroptosis might influence on the tumorigenesis, and also immunotherapy against tumors. Here we will summarize the recent advance of ferroptosis mediated by gut microbiota metabolites, which potentially acts as regulator(s) on immune cells in TME for therapy against tumor.

Team players in the pathogenesis of metabolic dysfunctions-associated steatotic liver disease: The basis of development of pharmacotherapy

Nutrient metabolism is regulated by several factors. Social determinants of health with or without genetics are the primary regulator of metabolism, and an unhealthy lifestyle affects all modulators and mediators, leading to the adaptation and finally to the exhaustion of cellular functions. Hepatic steatosis is defined by presence of fat in more than 5% of hepatocytes. In hepatocytes, fat is stored as triglycerides in lipid droplet. Hepatic steatosis results from a combination of multiple intracellular processes. In a healthy individual nutrient metabolism is regulated at several steps. It ranges from the selection of nutrients in a grocery store to the last step of consumption of ATP as an energy or as a building block of a cell as structural component. Several hormones, peptides, and genes have been described that participate in nutrient metabolism. Several enzymes participate in each nutrient metabolism as described above from ingestion to generation of ATP. As of now several publications have revealed very intricate regulation of nutrient metabolism, where most of the regulatory factors are tied to each other bidirectionally, making it difficult to comprehend chronological sequence of events. Insulin hormone is the primary regulator of all nutrients' metabolism both in prandial and fasting states. Insulin exerts its effects directly and indirectly on enzymes involved in the three main cellular function processes; metabolic, inflammation and repair, and cell growth and regeneration. Final regulators that control the enzymatic functions through stimulation or suppression of a cell are nuclear receptors in especially farnesoid X receptor and peroxisome proliferator-activated receptor/RXR ligands, adiponectin, leptin, and adiponutrin. Insulin hormone has direct effect on these final modulators. Whereas blood glucose level, serum lipids, incretin hormones, bile acids in conjunction with microbiota are intermediary modulators which are controlled by lifestyle. The purpose of this review is to overview the key players in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) that help us understand the disease natural course, risk stratification, role of lifestyle and pharmacotherapy in each individual patient with MASLD to achieve personalized care and target the practice of precision medicine. PubMed and Google Scholar databases were used to identify publication related to metabolism of carbohydrate and fat in states of health and disease states; MASLD, cardiovascular disease and cancer. More than 1000 publications including original research and review papers were reviewed.

Graphene Quantum Dots Inhibit Lipid Peroxidation in Biological Membranes

Excessive reactive oxygen species (ROS) in cellular environments leads to oxidative stress, which underlies numerous diseases, including inflammatory diseases, neurodegenerative diseases, cardiovascular diseases, and cancer. Oxidative stress can be particularly damaging to biological membranes such as those found in mitochondria, which are abundant with polyunsaturated fatty acids (PUFAs). Oxidation of these biological membranes results in concomitant disruption of membrane structure and function, which ultimately leads to cellular dysfunction. Graphene quantum dots (GQDs) have garnered significant interest as a therapeutic agent for numerous diseases that are linked to oxidative stress. Specifically, GQDs have demonstrated an ability to protect mitochondrial structure and function under oxidative stress conditions. However, the fundamental mechanisms by which GQDs interact with membranes in oxidative environments are poorly understood. Here, we used C11-BODIPY, a fluorescent lipid oxidation probe, to develop quantitative fluorescence assays that determine both the extent and rate of oxidation that occurs to PUFAs in biological membranes. Based on kinetics principles, we have developed a generalizable model that can be used to assess the potency of antioxidants that scavenge ROS in the presence of biological membranes. By augmenting our fluorescence assays with 1H NMR spectroscopy, the results demonstrate that GQDs scavenge nascent hydroxyl and peroxyl ROS that interact with membranes and that GQDs are potent inhibitors of ROS-induced lipid oxidation in PUFA-containing biological membranes. The antioxidant potency of GQDs is comparable to or even greater than established antioxidant molecules, such as ascorbic acid and Trolox. This work provides mechanistic insights into the mitoprotective properties of GQDs under oxidative stress conditions, as well as a quantitative framework for assessing antioxidant interactions in biological membrane systems.

The role of botanical triterpenoids and steroids in bile acid metabolism, transport, and signaling: Pharmacological and toxicological implications

Bile acids (BAs) are synthesized by the host liver from cholesterol and are delivered to the intestine, where they undergo further metabolism by gut microbes and circulate between the liver and intestines through various transporters. They serve to emulsify dietary lipids and act as signaling molecules, regulating the host's metabolism and immune homeostasis through specific receptors. Therefore, disruptions in BA metabolism, transport, and signaling are closely associated with cholestasis, metabolic disorders, autoimmune diseases, and others. Botanical triterpenoids and steroids share structural similarities with BAs, and they have been found to modulate BA metabolism, transport, and signaling, potentially exerting pharmacological or toxicological effects. Here, we have updated the research progress on BA, with a particular emphasis on new-found microbial BAs. Additionally, the latest advancements in targeting BA metabolism and signaling for disease treatment are highlighted. Subsequently, the roles of botanical triterpenoids in BA metabolism, transport, and signaling are examined, analyzing their potential pharmacological, toxicological, or drug interaction effects through these mechanisms. Finally, a research paradigm is proposed that utilizes the gut microbiota as a link to interpret the role of these important natural products in BA signaling.

Farnesol prevents chlorpyrifos nephrotoxicity by modulating inflammatory mediators, Nrf2 and FXR and attenuating oxidative stress

Chlorpyrifos (CPF) is a broad-spectrum insecticide widely employed in agricultural field for pest control. Exposure to CPF is associated with serious effects to the main organs, including kidneys. Significant evidence denotes that oxidative stress (OS) and inflammation are implicated in CPF toxicity. This study aimed to evaluate the potential of farnesol (FAR) to modulate inflammatory mediators and farnesoid-X-receptor (FXR) and Nrf2 in a rat model of CPF nephrotoxicity. CPF and FAR were orally supplemented for 28 days and blood and kidney samples were collected for investigations. CPF administration elevated blood creatinine and urea, kidney MDA and NO, and upregulated NF-κB p65, IL-1β, TNF-α, iNOS, and caspase-3. In addition, CPF upregulated kidney Keap1, and decreased GSH, antioxidant enzymes, and Nrf2, FXR, HO-1 and NQO-1. FAR ameliorated creatinine and urea, prevented histopathological alterations, decreased MDA and NO, and enhanced antioxidants in CPF-administered rats. FAR modulated NF-κB p65, iNOS, TNF-α, IL-1β, caspase-3, Keap1, HO-1, NQO-1, Nrf2 and FXR. In silico investigations revealed the binding affinity of FAR towards Keap1 and FXR, as well as NF-κB, caspase-3, iNOS, and HO-1. In conclusion, FAR prevents CPF-induced kidney injury by attenuating OS, inflammation, and apoptosis, effects associated with modulation of FXR, Nrf2/HO-1 signaling and antioxidants.

Let food be your medicine - dietary fiber

Dietary fiber (DF) cannot be digested and absorbed by the digestive tract, nor can it provide the energy needed to be burned for metabolic activities. Therefore, from the 1950s to the 1980s, DF received little attention in nutrition studies. With in-depth research and developments in global nutrition, people have gradually paid attention to the fact that DF occupies an essential position in the structure of nutrition, and it can ensure the healthy development of human beings. As early as 390 B.C., the ancient Greek physician Hippocrates proposed, "Let your food be your medicine, and your medicine be your food". This concept has been more systematically validated in modern scientific research, with numerous epidemiological studies showing that the dietary intake of DF-rich foods such as whole grains, root vegetables, legumes, and fruits has the potential to regulate the balance of the gut microbiota and thereby prevent diseases. However, the crosstalk between different types of DF and the gut microbiota is quite complex, and the effects on the organism vary. In this paper, we discuss research on DF and the gut microbiota and related diseases, aiming to understand the relationship between all three better and provide a reference basis for the risk reduction of related diseases.

Aging promotes metabolic dysfunction-associated steatotic liver disease by inducing ferroptotic stress

Susceptibility to the biological consequences of aging varies among organs and individuals. We analyzed hepatocyte transcriptomes of healthy young and aged male mice to generate an aging hepatocyte gene signature, used it to deconvolute transcriptomic data from humans and mice with metabolic dysfunction-associated liver disease, validated findings with functional studies in mice and applied the signature to transcriptomic data from other organs to determine whether aging-sensitive degenerative mechanisms are conserved. We discovered that the signature enriches in diseased livers in parallel with degeneration. It is also enriched in failing human hearts, diseased kidneys and pancreatic islets from individuals with diabetes. The signature includes genes that control ferroptosis. Aged mice develop more hepatocyte ferroptosis and liver degeneration than young mice when fed diets that induce metabolic stress. Inhibiting ferroptosis shifts the liver transcriptome of old mice toward that of young mice and reverses aging-exacerbated liver damage, identifying ferroptosis as a tractable, conserved mechanism for aging-related tissue degeneration.

Astragaloside IV ameliorates cisplatin-induced liver injury by modulating ferroptosis-dependent pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The use of antineoplastic drugs, such as cisplatin, in clinical practice can cause adverse effects in patients, such as liver injury, which limits their long-term use. Therefore, there is an urgent need to develop alternative therapeutic strategies or drugs to minimize cisplatin-induced liver injury. Huangqi, the root of Astragalus membranaceus, is extensively used in traditional Chinese medicine (TCM) and has been employed in treating diverse liver injuries. Astragalus membranaceus contains several bioactive constituents, including triterpenoid saponins, one of which, astragaloside IV (ASIV), has been reported to have anti-inflammatory and antioxidant stress properties. However, its potential in ameliorating cisplatin-induced liver injury has not been explored.

AIM OF THE STUDY

The objective of this study was to examine the mechanism by which ASIV protects against cisplatin-induced liver injury.

MATERIALS AND METHODS

This study established a model of cisplatin-induced liver injury in mice, followed by treatment with various doses of astragaloside IV (40 mg/kg, 80 mg/kg). In addition, a model of hepatocyte ferroptosis in AML-12 cells was established using RSL3. The mechanism of action of astragaloside IV was investigated using a range of methods, including Western blot assay, qPCR, immunofluorescence, histochemistry, molecular docking, and high-content imaging system.

RESULTS

The findings suggested a significant improvement in hepatic injury, inflammation and oxidative stress phenotypes with the administration of ASIV. Furthermore, network pharmacological analyses provided evidence that a major pathway for ASIV to attenuate cisplatin-induced hepatic injury entailed the cell death cascade pathway. It was observed that ASIV effectively inhibited ferroptosis both in vivo and in vitro. Subsequent experimental outcomes provided further validation of ASIV's ability to hinder ferroptosis through the inhibition of PPARα/FSP1 signaling pathway. The current findings suggest that ASIV could function as a promising phytotherapy composition to alleviate cisplatin-induced liver injury.

CONCLUSIONS

The current findings suggest that astragaloside IV could function as a promising phytotherapy composition to alleviate cisplatin-induced liver injury.

Ferroptosis: Iron-mediated cell death linked to disease pathogenesis

Ferroptosis is an iron-mediated regulatory cell death pattern characterized by oxidative damage. The molecular regulating mechanisms are related to iron metabolism, lipid peroxidation, and glutathione metabolism. Additionally, some immunological signaling pathways, such as the cyclic GMP-AMP synthase-stimulator ofinterferon genes axis, Janus kinase-signal transducer and activator of transcription 1 axis, and transforming growth factor beta 1-Smad3 axis may also participate in the regulation of ferroptosis. Studies have shown that ferroptosis is closely related to many diseases such as cancer, neurodegenerative diseases, inflammatory diseases, and autoimmune diseases. Considering the pivotal role of ferroptosis-regulating signaling in the pathogenesis of diverse diseases, the development of ferroptosis inducers or inhibitors may have significant clinical potential for the treatment of the aforementioned conditions.