The lipid peroxidation product EKODE exacerbates colonic inflammation and colon tumorigenesis

Matrix metalloproteinase 9 implication during colorectal carcinogenesis. Effect of doxycycline

BACKGROUND

Matrix metalloproteinases (MMPs), including MMP9, play a significant role in colorectal cancer (CRC) progression, mainly by extracellular matrix remodeling. However, little is known about MMP9 role in aberrant crypt foci (ACF) cluster formation, the earliest colon preneoplastic lesions.

AIMS AND METHODS

We conducted a bioinformatics analysis of MMPs expression in CRC using Gene Expression Profiling Interactive Analysis2 (GEPIA2). Subsequently, we investigated MMP9 expression during the early stage of colon carcinogenesis in mice and assessed the effect of doxycycline (DOX), a global inhibitor of MMPs, on ACF cluster formation. Thus, NMRI mice received two weekly injections of 1,2-Dimethylhydrazine (DMH, 20 mg/kg, subcutaneously), followed or not by DOX (100 mg/kg, orally, from the 4th to the 6th week).

RESULTS

GEPIA2 analysis indicated that among the 28 identified MMPs with collagenase and doxycycline-sensitive activities, MMPs 1, 3, 7, 9, and 13 were overexpressed in CRC tissues. Moreover, only MMP1 and MMP9 correlated well with collagen expression in colorectal tumors. In vivo, methylene blue-stained DMH-treated colons revealed multiple ACF clusters at week 6, associated with mucosa remodeling and sustained nitrosative stress as attested by enhanced collagen fibers, malondialdehyde level, and nitrotyrosine deposits. Pyrosequencing showed increased methylation at the tenth CpG site of the MMP9 promoter, which was associated with increased MMP9 expression. Interestingly, DOX attenuated the number and size of ACF clusters and mucosa remodeling without rebalancing nitrosative stress.

CONCLUSION

Overexpression of MMP9 occurs early during colorectal carcinogenesis, and doxycycline may control the pathological remodeling of colon mucosa into ACF clusters by attenuating MMP9 activity.

Chlorogenic acid simultaneously enhances the oxidative protection and anti-digestibility of porous starch

Porous starch (PS) has been utilized as an oral protective carrier to enhance the oxidative stability of liposoluble nutrients. However, PS releases more glucose during digestion, thereby increasing the risk of chronic diseases. Chlorogenic acid (CA) has excellent antioxidant properties and enhances the starch digestion resistance. To simultaneously enhance the oxidative protection and anti-digestibility, PS was blended with CA. Morphological analysis revealed that PSs with pores absorbed liposoluble substances. Surface area, total pore volume, and oxidative stability analyses demonstrated that rice starch (RS) enzymatically hydrolyzed for 12 h (PS12) loaded more substances and exerted a better protective effect in cooperation with CA. Simulated digestion confirmed that PS12-CA1 had the best anti-digestibility among PS12-CAs and a similar digestibility as RS. Additionally, CA treatment resulted in more anti-digestive V-type crystals in PSs, which resisted digestion. This study showed that the combination of PS and CA simultaneously enhanced oxidative protection and reduced the digestibility of PS. Thus, CA treatment makes PS a better oral nutrient delivery.

Lipotoxicity, lipid peroxidation and ferroptosis: a dilemma in cancer therapy

The vulnerability of tumor cells to lipid peroxidation, driven by redox imbalance and lipid overabundance within the tumor microenvironment (TME), has become a focal point for novel antitumor strategies. Ferroptosis, a form of regulated cell death predicated on lipid peroxidation, is emerging as a promising approach. Beyond their role in directly eliminating tumor cells, lipid peroxidation and its products, such as 4-hydroxynonenal (HNE), exert an additional influence by damaging DNA and shaping an environment conducive to tumor growth and metastasis. This process polarizes macrophages towards a pro-inflammatory phenotype, dampens the antigen-presenting capacity of dendritic cells (DCs), and undermines the cytotoxic functions of T and NK cells. Furthermore, it transforms neutrophils into pro-tumorigenic polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). The lipid peroxidation of stroma cells also contributes to tumor progression. Although advanced nanotherapies have shown the ability to target tumor cells precisely, they often overlook the nuanced effects of lipid peroxidation products. In this review, we highlight a synergistic mechanism in which lipid peroxidation products and ferroptosis contribute to an immunosuppressive state that is temporally distinct from cell death. This insight broadens our understanding of ferroptosis-derived immunosuppression, encompassing all types of immune cells within the TME. This review aims to catalyze further research in this underexplored area, emphasizing the potential of lipid peroxidation products to hinder the clinical translation of ferroptosis-based therapies.

Oxidized Polyunsaturated Fatty Acid Promotes Colitis and Colitis-Associated Tumorigenesis in Mice

BACKGROUND AND AIMS

Human studies suggest that a high intake of polyunsaturated fatty acid (PUFA) is associated with an increased risk of inflammatory bowel disease (IBD). PUFA is highly prone to oxidation. To date, it is unclear whether unoxidized or oxidized PUFA is involved in the development of IBD. Here, we aim to compare the effects of unoxidized PUFA vs oxidized PUFA on the development of IBD and associated colorectal cancer.

METHODS

We evaluated the effects of unoxidized and oxidized PUFA on dextran sodium sulfate (DSS)-induced and IL-10 knockout-induced colitis, and azoxymethane/DSS-induced colon tumorigenesis in mice. Additionally, we studied the roles of gut microbiota and Toll-like receptor 4 (TLR4) signaling involved.

RESULTS

Administration of a diet containing oxidized PUFA, at human consumption-relevant levels, increases the severity of colitis and exacerbates the development of colitis-associated colon tumorigenesis in mice. Conversely, a diet rich in unoxidized PUFA does not promote colitis. Furthermore, oxidized PUFA worsens colitis-associated intestinal barrier dysfunction and leads to increased bacterial translocation, and it fails to promote colitis in TLR4 knockout mice. Finally, oxidized PUFA alters the diversity and composition of gut microbiota, and it fails to promote colitis in mice lacking the microbiota.

CONCLUSIONS

These results support that oxidized PUFA promotes the development of colitis and associated tumorigenesis in mouse models via TLR4- and gut microbiota-dependent mechanisms. Our findings highlight the potential need to update regulation policies and industrial standards for oxidized PUFA levels in food.

Integrating widely targeted and oxylipin-targeted lipidomics unravels lipid characteristic evolution and oxidation markers in walnuts during deterioration

The susceptibility of walnut lipids to deterioration constitutes challenges for industry development, and the oxylipins formed during this process remain to be explored. This study employed lipidomics to reveal the dynamic evolution of lipid characteristics and identify oxidation markers from oxylipins in walnuts during accelerated storage. Glycerophospholipid (GP) content continuously declined in the initial and severe deterioration stages. The accumulation of diglycerides and partial lysophospholipids characterized initial deterioration. Triglycerides were prone to direct oxidation, while GPs tended to be first hydrolyzed. GP metabolism especially phosphatidylethanolamine degradation triggered walnut deterioration. Moreover, ten oxylipins derived from linoleic acids were identified in walnuts. Trans-EKODE-(E)-Ib, 13-HODE, 9-HODE, and 9(S),12(S),13(S)-TriHOME were screened as oxidation markers. The cellular structure exhibited the cell membrane and oil body membrane rupture during deterioration. Potential mechanisms of lipid deterioration were proposed, providing a scientific basis and guidance in optimizing quality control strategies and assessing practical deterioration degrees of walnuts.

Understanding the physiological mechanisms and therapeutic targets of diseases: Lipidomics strategies

As a pivotal branch of metabolomics, lipidomics studies global changes in lipid metabolism under different physiological and pathological conditions or drug interventions, discovers key lipid markers, and elaborates the associated lipid metabolism network. There are a considerable number of lipids in the host, which act on various functional networks such as metabolism and immune regulation. As an indispensable research method, lipidomics plays a key character in the analysis of lipid composition in organisms, the elaboration of the physiological mechanism of lipids, and the decoding of their character in the occurrence and development of diseases by exploring the character of lipids in the host environmental network. As an essential means of driving lipidomics research, High-throughput and High-resolution mass spectrometry is helpful in exploring disease phenotypic characteristics, diagnosing disease biomarkers, regulating related metabolic pathways, and discovering related active components. In this paper, we discuss the specific role of lipidomics in the analysis of disease diagnosis, prognosis and treatment, which is conducive to the realization of accurate and personalized medicine.

DS0384 Alleviates Necrotizing Enterocolitis: Secretes N-carbamyl glutamic Acid and Participates in Lipid Metabolism and Lipid Peroxidation Processes

Necrotizing enterocolitis (NEC) is a life-threatening inflammatory bowel disease linked to gut microbiome dysbiosis. This study evaluates the efficacy of Limosilactobacillus reuteri strain DS0384, which secretes N-carbamyl glutamic acid (NCG), in modulating lipid peroxidation and inflammatory pathways in NEC. After pretreatment with DS0384, NEC mouse model was induced by gavage with bacteria-containing formula. NCG levels in the ileum were measured via CE-TOFMS metabolomic analysis. Additionally, rat small intestinal epithelial IEC-6 cells were exposed to lipopolysaccharide (LPS), treated with DS0384 DNA (D-DNA), and/or transfected to overexpress fatty acid synthase (FASN) and Toll-like receptor 4 (TLR4). Lipid peroxidation, peroxidation and inflammatory factors and NF-κB pathways were analysed. Immunofluorescence was used to measure the expression levels of ZO-1 and TLR4 in the ileum. DS0384 treatment significantly reduced more histological abnormalities, apoptosis, and TLR4 expression in NEC mice, while restoring NCG levels, downregulating FASN and inhibiting lipid peroxidation and inflammation. Pre-treatment with D-DNA maintained cell vitality, reduced apoptosis, and suppressed TLR4/NF-κB-mediated inflammasome activation. Overexpression of FASN or TLR4 reversed these effects. DS0384 is a promising therapeutic against NEC, enhancing gut barrier integrity and modulating inflammatory and oxidative responses, suggesting potential clinical benefits in preventing NEC progression.

The role of ALDHs in lipid peroxidation-related diseases

Lipid peroxidation presents the oxidative degradation of polyunsaturated fatty acids lincited by reactive species. Excessive accumulation of lipid peroxidation byproducts, including 4-hydroxy-2-nonenal (4-HNE) and malondialdehyde (MDA), causes protein dysfunction and various illnesses. Aldehyde dehydrogenases (ALDHs) catalyze the metabolism of both endogenous and exogenous aldehydes. These enzymes participate in detoxification and intermediary metabolism. Contemporary research has affirmed the involvement of both enzymatic and non-enzymatic pathways of ALDHs in modulating the evolution of diseases associated with lipid peroxidation. This review provides an overview of the biological functions and clinical implications concerning the enzymatic and non-enzymatic pathways of ALDHs in diseases related to lipid peroxidation, such as, non-alcoholic fatty liver disease (NAFLD), atherosclerosis, and type 2 diabetes (T2DM). Furthermore, the activators or inhibitors of ALDHs represent a promising therapeutic strategy for lipid peroxidation-related diseases.

Wolfberry (Lycium barbarum) glycopeptide attenuates dopaminergic neurons loss by inhibiting lipid peroxidation in Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a common neurodegenerative disorder characterized clinically by motor dysfunction due to gradual loss of dopaminergic neurons in the nigrostriatal system. Currently, medications such as levodopa preparations, offer only temporary symptomatic relief without preventing neuronal loss or halting disease progression. In traditional Chinese medicine (TCM), a particular type of wolfberry or goji berry, the fruit of Lycium barbarum L., has been historically regarded for its neuroprotective properties, potentially offering therapeutic benefits for PD. However, scientific validation of these effects remains limited.

PURPOSE

This study aims to investigate the neuroprotective effects of wolfberry glycopeptide (WGP) on PD progression in various animal models, and to elucidate the underlying mechanisms responsible for its therapeutic action.

STUDY DESIGN

Diverse canonical animal models, including 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, 6-hydroxydopamine (6-OHDA)-treated rats, and α-synuclein overexpressed hSNCAA53T mice, were used to evaluate WGP's anti-PD efficacy. Behavioral deficits and pathological damage to dopaminergic neurons were assessed to determine WGP's neuroprotective potential.

METHODS

After establishing the animal models and administering WGP treatment, PD-like behaviors were assessed using pole test, rotarod test and gait analysis. Dopaminergic neurons loss in the midbrain and striatum was detected by means of immunohistochemistry, immunofluorescence and Western blot analysis. Inflammatory markers in these brain regions were measured by ELISA.

RESULTS

WGP treatment significantly alleviated motor deficits as well as progressive dopaminergic neurons loss. Mechanistically, WGP exerted its neuroprotective effects by regulating iron homeostasis, specifically through the modulation of key proteins such as TFRC, FTH1, and FPN. This function contributed to reducing the accumulation of lipid peroxidation in nigrostriatal system, thereby mitigating neuroinflammation and neuronal degeneration.

CONCLUSION

Our findings underscore the innovative potential of WGP as a neuroprotective agent in PD, with a unique mechanism of action targeting iron homeostasis and lipid peroxidation-driven neurodegeneration. This study advances the understanding of TCM's therapeutic contributions to neurodegeneration and positions WGP as a strong candidate for further clinical development in PD treatment.

Antioxidant Role of Probiotics in Inflammation-Induced Colorectal Cancer

Colorectal cancer (CRC) continues to be a significant contributor to global morbidity and mortality. Emerging evidence indicates that disturbances in gut microbial composition, the formation of reactive oxygen species (ROS), and the resulting inflammation can lead to DNA damage, driving the pathogenesis and progression of CRC. Notably, bacterial metabolites can either protect against or contribute to oxidative stress by modulating the activity of antioxidant enzymes and influencing signaling pathways that govern ROS-induced inflammation. Additionally, microbiota byproducts, when supplemented through probiotics, can affect tumor microenvironments to enhance treatment efficacy and selectively mediate the ROS-induced destruction of CRC cells. This review aims to discuss the mechanisms by which taxonomical shifts in gut microbiota and related metabolites such as short-chain fatty acids, secondary bile acids, and trimethylamine-N-oxide influence ROS concentrations to safeguard or promote the onset of inflammation-mediated CRC. Additionally, we focus on the role of probiotic species in modulating ROS-mediated signaling pathways that influence both oxidative status and inflammation, such as Nrf2-Keap1, NF-κB, and NLRP3 to mitigate carcinogenesis. Overall, a deeper understanding of the role of gut microbiota on oxidative stress may aid in delaying or preventing the onset of CRC and offer new avenues for adjunct, CRC-specific therapeutic interventions such as cancer immunotherapy.

The emerging role of oxidative stress in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic immune-mediated condition that affects the digestive system and includes Crohn's disease (CD) and ulcerative colitis (UC). Although the exact etiology of IBD remains uncertain, dysfunctional immunoregulation of the gut is believed to be the main culprit. Amongst the immunoregulatory factors, reactive oxygen species (ROS) and reactive nitrogen species (RNS), components of the oxidative stress event, are produced at abnormally high levels in IBD. Their destructive effects may contribute to the disease's initiation and propagation, as they damage the gut lining and activate inflammatory signaling pathways, further exacerbating the inflammation. Oxidative stress markers, such as malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and serum-free thiols (R-SH), can be measured in the blood and stool of patients with IBD. These markers are elevated in patients with IBD, and their levels correlate with the severity of the disease. Thus, oxidative stress markers can be used not only in IBD diagnosis but also in monitoring the response to treatment. It can also be targeted in IBD treatment through the use of antioxidants, including vitamin C, vitamin E, glutathione, and N-acetylcysteine. In this review, we summarize the role of oxidative stress in the pathophysiology of IBD, its diagnostic targets, and the potential application of antioxidant therapies to manage and treat IBD.

Metabolic trade-offs in Neonatal sepsis triggered by TLR4 and TLR1/2 ligands result in unique dysfunctions in neural breathing circuits

Neonatal sepsis remains one of the leading causes of mortality in newborns. Several brainstem-regulated physiological processes undergo disruption during neonatal sepsis. Mechanistic knowledge gaps exist at the interplay between metabolism and immune activation to brainstem neural circuits and pertinent physiological functions in neonates. To delineate this association, we induced systemic inflammation either by TLR4 (LPS) or TLR1/2 (PAM3CSK4) ligand administration in postnatal day 5 mice (PD5). Our findings show that LPS and PAM3CSK4 evoke substantial changes in respiration and metabolism. Physiological trade-offs led to hypometabolic-hypothermic responses due to LPS, but not PAM3CSK4, whereas to both TLR ligands blunted respiratory chemoreflexes. Neuroinflammatory pathways modulation in brainstem showed more robust effects in LPS than PAM3CSK4. Brainstem neurons, microglia, and astrocyte gene expression analyses showed unique responses to TLR ligands. PAM3CSK4 did not significantly modulate gene expression changes in GLAST-1 positive brainstem astrocytes. PD5 pups receiving PAM3CSK4 failed to maintain a prolonged metabolic state repression, which correlated to enhanced gasping latency and impaired autoresuscitation during anoxic chemoreflex challenges. In contrast, LPS administered pups showed no significant changes in anoxic chemoreflex. Electrophysiological studies from brainstem slices prepared from pups exposed to either TLR4 or PAM3CSK4 showed compromised transmission between preBötzinger complex and Hypoglossal as an exclusive response to the TLR1/2 ligand. Spatial gene expression analysis demonstrated a region-specific modulation of PAM3CSK4 within the raphe nucleus relative to other anatomical sites evaluated. Our findings suggest that metabolic changes due to inflammation might be a crucial tolerance mechanism for neonatal sepsis preserving neural control of breathing.

Magnolol ameliorates fumonisin B1-induced oxidative damage and lipid metabolism dysfunction in astrocyte-like C6 cells

The neurotoxicity of fumonisin B1 (FB1), a commonly detected mycotoxin in crops and the environment, has attracted considerable attention in recent years. However, no effective method for eliminating FB1 completely exists due to the thermal stability and water solubility of this mycotoxin. Magnolol (MAG) is a neolignane with antioxidative and neuroprotective effects. It has been applied in neurotoxicity treatment. However, the application of MAG to attenuate FB1-induced toxicity has not been reported. This study explored the protective mechanism of MAG against FB1-induced damage in C6 cells through antioxidant and lipid metabolism modulation. Results showed that exposure to 15 μM FB1 caused oxidative stress by changing the levels of malondialdehyde, reactive oxygen species, total superoxide dismutase, catalase, and total glutathione. These changes were reversed by MAG addition, especially at the concentration of 80 μM. The protective effects of MAG were further confirmed by the reduction in the phosphorylation levels of proteins in the MAPK signaling pathway. Lipidomics analysis identified 263 lipids, which belong to 24 lipid classes. Among all of the identified lipids, triglycerides (TGs), diglycerides (DGs), phosphatidylcholines (PCs), wax monoesters (WEs), Cers, and phosphatidylethanolamines (PEs) were major categories. Moreover, nine categories of lipids showed the opposite change trend in the FB1 exposure and MAG 80 groups. A further investigation of the 34 co-occurring differential lipids with remarkable changes (P value < 0.05 and VIP value > 1) in the control, FB1 exposure, and MAG 80 groups was performed. Therein, nine lipids (PCs, LPCs, and SM) were screened out as potential biomarkers to reveal the cytoprotective effects of MAG. This work is the first to investigate the rescue mechanism of MAG in FB1-induced cytotoxicity. The obtained results may expand the application of MAG to alleviate the toxicity of mycotoxins.

Highly Effective Nobiletin-MPN in Yeast Microcapsules for Targeted Modulation of Oxidative Stress, NLRP3 Inflammasome Activation, and Immune Responses in Ulcerative Colitis

Inflammatory bowel disease (IBD) etiology is intricately linked to oxidative stress and inflammasome activation. Natural antioxidant nobiletin (NOB) contains excellent anti-inflammatory properties in alleviating intestinal injury. However, the insufficient water solubility and low bioavailability restrict its oral intervention for IBD. Herein, we constructed a highly efficient NOB-loaded yeast microcapsule (YM, NEFY) exhibiting marked therapeutic efficacy for dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) at a low oral dose of NOB (20 mg/kg). We utilized the metal polyphenol network (MPN) formed by self-assembly of epigallocatechin gallate (EGCG) and FeCl3 as the intermediate carrier to improve the encapsulation efficiency (EE) of NOB by 4.2 times. These microcapsules effectively alleviated the inflammatory reaction and oxidative stress of RAW264.7 macrophages induced by lipopolysaccharide (LPS). In vivo, NEFY with biocompatibility enabled the intestinal enrichment of NOB through controlled gastrointestinal release and macrophage targeting. In addition, NEFY could inhibit NLRP3 inflammasome and balance the macrophage polarization, which favors the complete intestinal mucosal barrier and recovery of colitis. Based on the oral targeted delivery platform of YM, this work proposes a novel strategy for developing and utilizing the natural flavone NOB to intervene in intestinal inflammation-related diseases.

Black rice anthocyanins nanoparticles based on bovine serum albumin and hyaluronic acid: Preparation, characterization, absorption and intestinal barrier function protection in Caco-2 monolayers

Black rice anthocyanins (BRA) nanoparticles (NPs) were prepared using hyaluronic acid (HA), oxidized hyaluronic acid (OHA) and bovine serum albumin (BSA) to enhance the absorption and bioactivity of anthocyanins (ACNs). Results showed that HA/OHA-BSA-BRA NPs had a spherical morphology and excellent dispensability, with hydrated radius ~ 500 nm, zeta potential ~ - 30 mV, and encapsulation efficiency ~21 %. Moreover, using in vitro gastrointestinal release assay, we demonstrated that both BRA-loaded NPs exhibited effective controlled release properties of ACNs, significantly enhancing the accessibility of ACNs to the intestine. Cellular experiments showed that both two NPs had good biocompatibility and increased uptake of BRA. Furthermore, in comparison to the free BRA group, both BRA NPs groups significantly decreased the TEER value and increased the expression of tight junction proteins (Claudin 1, Occludin and ZO-1) in Caco-2 cell monolayers with LPS-induced damage. Therefore, our study demonstrated that HA/OHA-BSA-BRA NPs are promising carriers of ACNs and can effectively prevent the LPS-induced intestinal barrier injury in vitro.

Phosphatidylethanolamine Improves Postnatal Growth Retardation by Regulating Mucus Secretion of Intestinal Goblet Cells in Piglets

Phosphatidylethanolamine (PE), a multifunctional phospholipid, is necessary for neonate development. This study aimed to explore the impact of the regulation of exogenous PE on postnatal growth retardation (PGR) by improving intestinal barrier function. Thirty-two neonatal pigs were divided into four groups according to their body weight (BW 2.79 ± 0.50 kg or 1.88 ± 0.40 kg) at 7 days old, CON-NBW, PE-NBW, CON-PGR, and PE-PGR. PE was supplemented to NBW piglets and PGR piglets during lactation and post-weaning periods. Compared with the NBW piglets, the growth performance of PGR piglets was lower, while PE improved the poor growth performance. PGR piglets showed injured intestinal morphology, as evidenced by the reduced ratio of villus height to crypt depth (VH/CD) and goblet cell numbers in the jejunum and ileum. PE recovered the intestinal barrier injury by increasing VH/CD and goblet cell numbers. The decreased MUC2 mRNA and protein expressions were observed in the small intestine of PGR piglets, and PE remarkably increased the expression of MUC2. Mechanistically, PE increased the goblet cell differentiation promoting gene spdef mRNA levels and reduced the mRNA expressions involved in endoplasmic reticulum stress in the jejunal and ileal mucosa of PGR piglets. Overall, we found that PE alleviated growth retardation by regulating intestinal health and generalized its application in neonates.

Glutathione peroxidase 4 suppresses manganese-dependent oxidative stress to reduce colorectal tumorigenesis

The role of glutathione peroxidase 4 (GPX4) in ferroptosis and various cancers is well-established; however, its specific contribution to colorectal cancer has been unclear. Surprisingly, in a genetic mouse model of colon tumors, the deletion of GPX4 specifically in colon epithelial cells increased tumor burden but decreased oxidized glutathione. Notably, this specific GPX4 deletion did not enhance susceptibility to dextran sodium sulfate (DSS)-induced colitis in mice with varied iron diets but showed vulnerability in mice with a vitamin E-deficient diet. Additionally, a high manganese diet heightened susceptibility, while a low manganese diet reduced DSS-induced colitis in colon epithelial-specific GPX4-deficient mice. Strikingly, the low manganese diet also significantly reduced colorectal cancer formation in both colon epithelial-specific GPX4-deficient and wildtype mice. Mechanistically, antioxidant proteins, especially manganese-dependent superoxide dismutase (MnSOD or SOD2), correlated with disease severity. Treatment with tempol, a superoxide dismutase mimetic radical scavenger, suppressed GPX4 deficiency-induced colorectal tumors. In conclusion, the study elucidates the critical role of GPX4 in inhibiting colorectal cancer progression by regulating oxidative stress in a manganese-dependent manner. The findings underscore the intricate interactions between GPX4, dietary factors, and their collective influence on colorectal cancer development, providing potential insights for personalized therapeutic strategies.

PPARs/macrophages: A bridge between the inflammatory response and lipid metabolism in autoimmune diseases

Autoimmune diseases (AIDs) are a collection of pathologies that arise from autoimmune reactions and lead to the destruction and damage of the body's tissues and cellular components, ultimately resulting in tissue damage and organ dysfunction. The anti-inflammatory effects of the peroxisome proliferator-activated receptor (PPAR), a pivotal regulator of lipid metabolism, are crucial in the context of AIDs. PPAR mitigates AIDs by modulating macrophage polarization and suppressing the inflammatory response. Numerous studies have demonstrated the crucial involvement of lipid metabolism and phenotypic switching in classically activated (M1)/alternatively activated (M2)-like macrophages in the inflammatory pathway of AIDs. However, the precise mechanism by which PPAR, a critical mediator between of lipid metabolism and macrophage polarization, regulates macrophage polarization remains unclear. This review aimed to clarify the role of PPAR and macrophages in the triangular relationship among AIDs, lipid metabolism, and inflammatory response, and aims to summarize the mechanism of the PPAR-mediated macrophage activation and polarization, which impacts the progression and development of AIDs.

Prognostic modelling of colorectal cancer based on oxidative stress-related genes

BACKGROUND

Colon cancer is one of the most prevalent cancers of the digestive tract. There is mounting evidence that genes associated with oxidative stress might affect the tumour immune microenvironment during tumour growth, maintenance, and treatment response. However, how oxidative stress-related genes affect prognostic importance, tumour microenvironment features, and treatment outcomes in colon cancer patients has not been fully elucidated.

METHODS

The Cancer Genome Atlas (TCGA) dataset was used to construct a signature model and nomogram using step and Cox regression approaches to investigate how gene expression affected immunological responses to colon cancer, including the degree of immune infiltration, MSI, and drug sensitivity.

RESULTS AND CONCLUSIONS

The nomogram and the signature model had strong prognostic potential for colon cancer, with gene expression highly correlated with multiple immune cells. The first signature model and nomogram including oxidative stress-related genes were constructed for use in clinical decision-making. In addition, SRD5A1, GSR, TXN, TRAF2 and TRAP1 were identified as potential biomarkers for colon cancer diagnosis and indicators for immunotherapy.

An Adverse Outcome Pathway Network for Chemically Induced Oxidative Stress Leading to (Non)genotoxic Carcinogenesis

Nongenotoxic (NGTX) carcinogens induce cancer via other mechanisms than direct DNA damage. A recognized mode of action for NGTX carcinogens is induction of oxidative stress, a state in which the amount of oxidants in a cell exceeds its antioxidant capacity, leading to regenerative proliferation. Currently, carcinogenicity assessment of environmental chemicals primarily relies on genetic toxicity end points. Since NGTX carcinogens lack genotoxic potential, these chemicals may remain undetected in such evaluations. To enhance the predictivity of test strategies for carcinogenicity assessment, a shift toward mechanism-based approaches is required. Here, we present an adverse outcome pathway (AOP) network for chemically induced oxidative stress leading to (NGTX) carcinogenesis. To develop this AOP network, we first investigated the role of oxidative stress in the various cancer hallmarks. Next, possible mechanisms for chemical induction of oxidative stress and the biological effects of oxidative damage to macromolecules were considered. This resulted in an AOP network, of which associated uncertainties were explored. Ultimately, development of AOP networks relevant for carcinogenesis in humans will aid the transition to a mechanism-based, human relevant carcinogenicity assessment that involves a substantially lower number of laboratory animals.

Electrophilic reactive aldehydes as a therapeutic target in colorectal cancer prevention and treatment

Colorectal cancer (CRC) is a major health problem worldwide. Dicarbonyl electrophiles, such as isolevuglandins (isoLGs), are generated from lipid peroxidation and form covalent adducts with amine-containing macromolecules. We have shown high levels of adducts of isoLGs in colonic epithelial cells of patients with CRC. We thus investigated the role of these reactive aldehydes in colorectal cancer development. We found that 2-hydroxybenzylamine (2-HOBA), a natural compound derived from buckwheat seeds that acts as a potent scavenger of electrophiles, is bioavailable in the colon of mice after supplementation in the drinking water and does not affect the colonic microbiome. 2-HOBA reduced the level of isoLG adducts to lysine as well as tumorigenesis in models of colitis-associated carcinogenesis and of sporadic CRC driven by specific deletion of the adenomatous polyposis coli gene in colonic epithelial cells. In parallel, we found that oncogenic NRF2 activation and signaling were decreased in the colon of 2-HOBA-treated mice. Additionally, the growth of xenografted human HCT116 CRC cells in nude mice was significantly attenuated by 2-HOBA supplementation. In conclusion, 2-HOBA represents a promising natural compound for the prevention and treatment of CRC.

Synthesis, Characterization of Low Molecular Weight Chitosan Selenium Nanoparticles and Its Effect on DSS-Induced Ulcerative Colitis in Mice

Selenium nanoparticles have attracted extensive attention due to their good bioavailability and activity. In the present study, a new form of selenium nanoparticle (Low molecular weight chitosan selenium nanoparticles (LCS-SeNPs)) were synthesized in a system of sodium selenite and acetic acid. The size, element state, morphology and elementary composition of LCS-SeNPs were characterized by using various spectroscopic and microscopic measurements. The protection of LCS-SeNPs against dextran sulfate sodium (DSS)-induced intestinal barrier dysfunction and the inherent mechanisms of this process were investigated. The results showed that LCS-SeNPs, with an average diameter of 198 nm, zero-valent and orange-red relatively uniform spherical particles were prepared. LCS-SeNPs were mainly composed of C, N, O and Se elements, of which Se accounted for 39.03% of the four elements C, N, O and Se. LCS-SeNPs reduced colon injury and inflammation symptoms and improved intestinal barrier dysfunction. LCS-SeNPs significantly reduced serum and colonic inflammatory cytokines TNF-α and IL-6 levels. Moreover, LCS-SeNPs remarkably increased antioxidant enzyme GSH-Px levels in serum and colonic tissue. Further studies on inflammatory pathways showed that LCS-SeNPs alleviated DSS-induced colitis through the NF-κB signaling pathway, and relieved inflammatory associated oxidative stress through the Nrf2 signaling pathway. Our findings suggested that LCS-SeNPs are a promising selenium species with potential applications in the treatment of oxidative stress related inflammatory intestinal diseases.

Multi-omics profiling reveals Chitinase-3-like protein 1 as a key mediator in the crosstalk between sarcopenia and liver cancer

Sarcopenia is prevalent in patients with hepatocellular carcinoma (HCC), and can adversely affect their outcomes. This study aims to explore the key mechanisms in the crosstalk between sarcopenia and HCC based on multi-omics profiling. A total of 136 male patients with HCC were enrolled. Sarcopenia was an independent risk factor for poor outcomes after liver transplantation (p < 0.05). Inflammatory cytokine and metabolomic profiling on these patients identified elevated plasma sTNF-R1/CHI3L1 and dysregulated lipid metabolism as related to sarcopenia and tumor recurrence risk concurrently (p < 0.05). Integrated analysis revealed close relationship between CHI3L1 and fatty acid metabolism. In mouse cachectic models by intraperitoneal injection of H22 cells, CHI3L1 was significantly elevated in the atrophic muscle tissue, as well as in circulation. In-vitro, CHI3L1 was up-regulated in muscle cells to protect itself from inflammatory damage through TNF-α/TNF-R1 signaling. CHI3L1 secreted by the muscle cells promoted the invasion of co-cultured HCC cells. Tumor tissue transcriptome data for 73 out of the 136 patients revealed that CHI3L1 may regulate fatty acid metabolism and oxidative stress. In vitro, CHI3L1 caused ROS and lipid accumulation. Targeted lipid profiling further proved that CHI3L1 was able to activate arachidonic acid metabolism, leading to lipid peroxide (LPO) accumulation. Meanwhile, LPO inhibition could compromise the remarkable pro-cancerous effects of CHI3L1. In conclusion, sarcopenia adversely affects the outcomes of liver transplantation for HCC. In sarcopenic patients, CHI3L1 was up-regulated and secreted by the skeletal muscle to protect itself through TNF-α/TNF-R1 signaling, which, in turn, can promote HCC tumor progression by inducing LPO accumulation.

Mechanism investigation and experiment validation of capsaicin on uterine corpus endometrial carcinoma

Background: Using bioinformatics analysis and experimental operations, we intend to analyze the potential mechanism of action of capsaicin target gene GATA1 in the treatment of uterine corpus endometrial carcinoma (UCEC) and develop a prognostic model for the disease to validate this model.

Methods: By obtaining capsaicin and UCEC-related DR-DEGs, the prognosis-related gene GATA1 was screened. The survival analysis was conducted via establishing high and low expression groups of GATA1. Whether the GATA1 could be an independent prognostic factor for UCEC, it was also validated. The therapeutic mechanism of capsaicin-related genes in UCEC was further investigated using enrichment analysis and immune methods as well as in combination with single-cell sequencing data. Finally, it was validated by cell experiments.

Results: GATA1, a high-risk gene associated with prognosis, was obtained by screening. Kaplan-Meier analysis showed that the survival of the high expression group was lower than that of low expression group. ROC curves showed that the prediction effect of the model was good and stable (1-year area under curve (AUC): 0.601; 2-years AUC: 0.575; 3-years AUC: 0.610). Independent prognosis analysis showed that the GATA1 can serve as an independent prognostic factor for UCEC. Enrichment analysis showed that “neuroactive Ligand - receptor interaction and TYPE I DIABETES MELLITUS” had a significant enrichment effect. Single-cell sequencing showed that the GATA1 was significantly expressed in mast cells. Cell experiments showed that the capsaicin significantly reduced the UCEC cell activity and migration ability, as well as inhibited the expression of GATA1.

Conclusion: This study suggests that the capsaicin has potential value and application prospect in the treatment of UCEC. It provides new genetic markers for the prognosis of UCEC patients.

Comparative Effects of Traditional Versus Genetically Modified Soybean Oils on Colon Tumorigenesis in Mice

Soybean oil, which has high abundance of linoleic acid (LA, 18:2ω-6), is the most commonly consumed edible oil. Recent studies support that a high dietary intake of LA is linked with increased risks of developing colonic inflammation and colon cancer. Here we studied the effects of the genetically modified Plenish^® soybean oil, which has low abundance of LA as well as α-linolenic acid (ALA, 18:3ω-3), on development of azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colon tumorigenesis in mice. Compared with a diet rich in traditional soybean oil, administration of a diet enriched with the Plenish oil has little impact on AOM/DSS-induced colon tumorigenesis, colonic infiltration of immune cells, expressions of inflammatory genes, and tumor markers. These results suggest that the traditional and the Plenish soybean oils have similar effects on development of AOM/DSS-induced colon cancer in mice.

Probiotics Interact With Lipids Metabolism and Affect Gut Health

Probiotics have attracted much attention due to their ability to modulate host intestinal microbe, participate in nutrient metabolism or immunomodulatory. Both inflammatory bowel disease (IBD) and bowel cancer are digestive system disease, which have become a global public health problem due to their unclear etiology, difficult to cure, and repeated attacks. Disturbed gut microbiota and abnormal lipid metabolism would increase the risk of intestinal inflammation. However, the link between lipid metabolism, probiotics, and IBD is unclear. In this review, we found that different lipids and their derivatives have different effects on IBD and gut microbes. ω-3 polyunsaturated fatty acids (PUFAs) docosahexaenoic acid, eicosapentaenoic acid, and their derivatives resolvin E1, resolvin D can inhibit oxidative stress and reactive oxygen species activate NFκB and MAPk pathway. While ω-6 PUFAs linoleic acid and arachidonic acid can be derived into leukotrienes and prostaglandins, which will aggravate IBD. Cholesterol can be converted into bile acids to promote lipid absorption and affect microbial survival and colonization. At the same time, it is affected by microbial bile salt hydrolase to regulate blood lipids. Low denstiy lipoprotein (LDL) is easily converted into oxidized LDL, thereby promoting inflammation, while high denstiy lipoprotein (HDL) has the opposite effect. Probiotics compete with intestinal microorganisms for nutrients or ecological sites and thus affect the structure of intestinal microbiota. Moreover, microbial short chain fatty acids, bile salt hydrolase, superoxide dismutase, glutathione, etc. can affect lipid metabolism and IBD. In conclusion, probiotics are directly or indirectly involved in lipids metabolism and their impact on IBD, which provides the possibility to explore the role of probiotics in improving gut health.

An age stratified analysis of the biomarkers in patients with colorectal cancer

Colorectal cancer (CRC), a common malignant tumor of the digestive tract, has a high incidence and mortality rate. Several recent studies have found that aging is associated with the increasing risk of cancer. Nevertheless, the expression status and function of age-related genes in CRC is still not well understood. In the study, we comprehensively analyzed the gene expression data of CRC patients from The Cancer Genome Atlas (TCGA) database. Age-related differential expression genes (age-related DEGs) in tumor tissues compared with normal tissues of CRC were further identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of age-related DEGs were performed by clusterProfiler of R. Afterwards, we used the STRING database to map the protein-protein interaction network of DEGs. We constructed prognostic model through univariate and multivariate COX regression analyses, and further evaluated their predictive power. The prognostic gene signature-related functional pathways were explored by gene set enrichment analysis (GSEA). The weighted gene co-expression network analysis (WGCNA) was used to identify key module associated with two prognostic gene signatures. Finally, we used the Metascape to perform functional enrichment analysis of genes in the key module. A total of 279 age-related DEGs were identified from the TCGA database. GO and KEGG enrichment analysis showed that the age-related DEGs were enriched in the Modulation of chemical synaptic transmission and Neuroactive ligand-receptor interaction. Moreover, we established a novel age-related gene signature (DLX2 and PCOLCE2) for overall survival in CRC, which was further predicted in both the training and validation sets. The results of GSEA demonstrated that numerous disease-related pathways were enriched in the high-risk group. We identified 43 genes related to the DLX2 and PCOLCE2 by the WGCNA co-expression network. We also found that these 43 genes were enriched in the cancer-related pathways. To sum up, the study identified an age-related gene signature for predicting the prognosis of CRC patients, which is conducive to the identification of novel prognostic molecular markers.

Dietary supplementation with Yucca schidigera extract alleviated heat stress-induced unfolded protein response and oxidative stress in the intestine of Nile tilapia (Oreochromis niloticus)

Heat stress due to global warming exerts deleterious effects on both humans and animals. However, nutritional strategies to reduce heat stress-induced intestinal mucosal barrier dysfunction and the underlying mechanisms remain largely unknown. In the present study, 240 tilapia were distributed into four treatment groups that were fed a basal diet supplemented with or without 0.1% Yucca schidigera extract under normal (28 °C) temperature or heat stress (36 °C) conditions for 2 weeks. Our results showed that tilapia exposed to heat stress resulted in growth arrest, intestinal dysfunction, oxidative damage, endoplasmic reticulum stress, and pro-inflammatory response, which were significantly relieved by yucca supplementation. The alleviative effect of Yucca schidigera extract was related to the down-regulation of mRNA expression of ubiquitin-proteasome system (Polyubiquitin, Proteasome 26S, Proteasome α5, Proteasome β3, and Ubiquitin-like 3) and inflammatory factors (tumor necrosis factor α, interleukin 1β, and interleukin 8), as well as the improved histological structure and activation of Hsp70, nuclear factor erythroid 2-related factor 2 signaling, interleukin 10, lysozyme, complement 3, and acid phosphatase in the intestine of tilapia. Collectively, these results indicated that heat stress-induced growth arrest, intestinal dysfunction, and oxidative damage were alleviated by dietary supplementation with Yucca schidigera extract. This offers a nutritional way of improving the growth and intestinal health of tilapia exposed to a hot environment.

Roles of Lipid Peroxidation-Derived Electrophiles in Pathogenesis of Colonic Inflammation and Colon Cancer

Redox stress is a common feature of gut disorders such as colonic inflammation (inflammatory bowel disease or IBD) and colorectal cancer (CRC). This leads to increased colonic formation of lipid-derived electrophiles (LDEs) such as 4-hydroxynonenal (4-HNE), malondialdehyde (MDA), trans, trans-2,4-decadienal (tt-DDE), and epoxyketooctadecenoic acid (EKODE). Recent research by us and others support that treatment with LDEs increases the severity of colitis and exacerbates the development of colon tumorigenesis in vitro and in vivo, supporting a critical role of these compounds in the pathogenesis of IBD and CRC. In this review, we will discuss the effects and mechanisms of LDEs on development of IBD and CRC and lifestyle factors, which could potentially affect tissue levels of LDEs to regulate IBD and CRC development.