Recent research has highlighted the pivotal role of lipoxygenases in modulating ferroptosis and immune responses by catalyzing the generation of lipid peroxides. However, the limitations associated with protein enzymes, such as poor stability, low bioavailability, and high production costs, have motivated researchers to explore biomimetic materials with lipoxygenase-like activity. Here, we report the discovery of lipoxygenase-like two-dimensional (2D) MoS2nanosheets capable of catalyzing lipid peroxidation and inducing ferroptosis. The resulting catalytic products were successfully identified using mass spectrometry and a luminescent substrate. Unlike native lipoxygenases, MoS2 nanosheets exhibited exceptional catalytic activity at extreme pH, high temperature, high ionic strength, and organic solvent conditions. Structure-activity relationship analysis indicates that sulfur atomic vacancy sites on MoS2 nanosheets are responsible for their catalytic activity. Furthermore, the lipoxygenase-like activity of MoS2 nanosheets was demonstrated within mammalian cells and animal tissues, inducing distinctive ferroptotic cell death. In summary, this research introduces an alternative to lipoxygenase to regulate lipid peroxidation in cells, offering a promising avenue for ferroptosis induction.
- MeSH
- Biomimetic Materials chemistry pharmacology metabolism MeSH
- Disulfides * chemistry metabolism MeSH
- Ferroptosis * drug effects MeSH
- Catalysis MeSH
- Humans MeSH
- Lipoxygenase * metabolism chemistry MeSH
- Molybdenum chemistry metabolism MeSH
- Mice MeSH
- Nanostructures chemistry MeSH
- Lipid Peroxidation MeSH
- Structure-Activity Relationship MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- MeSH
- Acyltransferases MeSH
- Arachidonate 12-Lipoxygenase genetics MeSH
- Epidermis * MeSH
- Phospholipases MeSH
- Skin MeSH
- Ichthyosis, Lamellar * MeSH
- Lipids MeSH
- Mice MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Letter MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
Leukotrienes (LTs) and sphingolipids are critical lipid mediators participating in numerous cellular signal transduction events and developing various disorders, such as bronchial hyperactivity leading to asthma. Enzymatic reactions initiating production of these lipid mediators involve 5-lipoxygenase (5-LO)-mediated conversion of arachidonic acid to LTs and serine palmitoyltransferase (SPT)-mediated de novo synthesis of sphingolipids. Previous studies have shown that endoplasmic reticulum membrane protein ORM1-like protein 3 (ORMDL3) inhibits the activity of SPT and subsequent sphingolipid synthesis. However, the role of ORMDL3 in the synthesis of LTs is not known. In this study, we used peritoneal-derived mast cells isolated from ORMDL3 KO or control mice and examined their calcium mobilization, degranulation, NF-κB inhibitor-α phosphorylation, and TNF-α production. We found that peritoneal-derived mast cells with ORMDL3 KO exhibited increased responsiveness to antigen. Detailed lipid analysis showed that compared with WT cells, ORMDL3-deficient cells exhibited not only enhanced production of sphingolipids but also of LT signaling mediators LTB4, 6t-LTB4, LTC4, LTB5, and 6t-LTB5. The crosstalk between ORMDL3 and 5-LO metabolic pathways was supported by the finding that endogenous ORMDL3 and 5-LO are localized in similar endoplasmic reticulum domains in human mast cells and that ORMDL3 physically interacts with 5-LO. Further experiments showed that 5-LO also interacts with the long-chain 1 and long-chain 2 subunits of SPT. In agreement with these findings, 5-LO knockdown increased ceramide levels, and silencing of SPTLC1 decreased arachidonic acid metabolism to LTs to levels observed upon 5-LO knockdown. These results demonstrate functional crosstalk between the LT and sphingolipid metabolic pathways, leading to the production of lipid signaling mediators.
- MeSH
- Arachidonate 5-Lipoxygenase metabolism MeSH
- Eicosanoids analysis metabolism MeSH
- Membrane Proteins metabolism MeSH
- Mice, Inbred C57BL MeSH
- Mice, Knockout MeSH
- Mice MeSH
- Serine C-Palmitoyltransferase metabolism MeSH
- Sphingolipids analysis metabolism MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Stilbenoids are important components of foods (e.g., peanuts, grapes, various edible berries), beverages (wine, white tea), and medicinal plants. Many publications have described the anti-inflammatory potential of stilbenoids, including the widely known trans-resveratrol and its analogues. However, comparatively little information is available regarding the activity of their prenylated derivatives. One new prenylated stilbenoid (2) was isolated from Artocarpus altilis and characterized structurally based on 1D and 2D NMR analysis and HRMS. Three other prenylated stilbenoids were prepared synthetically (9-11). Their antiphlogistic potential was determined by testing them together with known natural prenylated stilbenoids from Macaranga siamensis and Artocarpus heterophyllus in both cell-free and cell assays. The inhibition of 5-lipoxygenase (5-LOX) was also shown by simulated molecular docking for the most active stilbenoids in order to elucidate the mode of interaction between these compounds and the enzyme. Their effects on the pro-inflammatory nuclear factor-κB (NF-κB) and the activator protein 1 (AP-1) signaling pathway were also analyzed. The THP1-XBlue-MD2-CD14 cell line was used as a model for determining their anti-inflammatory potential, and lipopolysaccharide (LPS) stimulation of Toll-like receptor 4 induced a signaling cascade leading to the activation of NF-κB/AP-1. The ability of prenylated stilbenoids to attenuate the production of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) was further evaluated using LPS-stimulated THP-1 macrophages.
- MeSH
- Cell Line MeSH
- Prostaglandin-Endoperoxide Synthases metabolism MeSH
- Enzyme Inhibitors pharmacology MeSH
- Humans MeSH
- Lipoxygenases metabolism MeSH
- NF-kappa B antagonists & inhibitors MeSH
- Prenylation * MeSH
- Signal Transduction drug effects MeSH
- Stilbenes pharmacology MeSH
- Transcription Factor AP-1 antagonists & inhibitors MeSH
- Inflammation prevention & control MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Plant oxylipins form a constantly growing group of signaling molecules that comprise oxygenated fatty acids and metabolites derived therefrom. In the last decade, the understanding of biosynthesis, metabolism, and action of oxylipins, especially jasmonates, has dramatically improved. Additional mechanistic insights into the action of enzymes and insights into signaling pathways have been deepened for jasmonates. For other oxylipins, such as the hydroxy fatty acids, individual signaling properties and cross talk between different oxylipins or even with additional phytohormones have recently been described. This review summarizes recent understanding of the biosynthesis, regulation, and function of oxylipins.
A new series of 1,2-diaryl-4-substituted-benzylidene-5(4H)-imidazolone derivatives 4a-l was synthesized. Their structures were confirmed by different spectroscopic techniques (IR, 1 H NMR, DEPT-Q NMR, and mass spectroscopy) and elemental analyses. Their cytotoxic activities in vitro were evaluated against breast, ovarian, and liver cancer cell lines and also normal human skin fibroblasts. Cyclooxygenase (COX)-1, COX-2 and lipoxygenase (LOX) inhibitory activities were measured. The synthesized compounds showed selectivity toward COX-2 rather than COX-1, and the IC50 values (0.25-1.7 µM) were lower than that of indomethacin (IC50 = 9.47 µM) and somewhat higher than that of celecoxib (IC50 = 0.071 µM). The selectivity index for COX-2 of the oxazole derivative 4e (SI = 3.67) was nearly equal to that of celecoxib (SI = 3.66). For the LOX inhibitory activity, the new compounds showed IC50 values of 0.02-74.03 µM, while the IC50 of the reference zileuton was 0.83 µM. The most active compound 4c (4-chlorobenzoxazole derivative) was found to have dual COX-2/LOX activity. All the synthesized compounds were docked inside the active site of the COX-2 and LOX enzymes. They linked to COX-2 through the N atom of the azole scaffold, while CO of the oxazolone moiety was responsible for the binding to amino acids inside the LOX active site.
- MeSH
- Anti-Inflammatory Agents, Non-Steroidal chemical synthesis chemistry pharmacology MeSH
- Arachidonate 5-Lipoxygenase metabolism MeSH
- Cyclooxygenase 2 metabolism MeSH
- Imidazoles chemical synthesis chemistry pharmacology MeSH
- Cyclooxygenase 2 Inhibitors chemical synthesis chemistry pharmacology MeSH
- Lipoxygenase Inhibitors chemical synthesis chemistry pharmacology MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Molecular Structure MeSH
- Drug Design * MeSH
- Molecular Docking Simulation MeSH
- Cell Survival drug effects MeSH
- Dose-Response Relationship, Drug MeSH
- Structure-Activity Relationship MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Lipoxygenases (LOX) constitute a heterogeneous family of lipid peroxidizing enzymes which catalyze the stereospecific insertion of molecular oxygen into polyunsaturated fatty acids. The primary products of LOX reaction are hydroperoxy fatty acids, which are rapidly reduced to the corresponding hydroxy derivatives. In mammalian organisms, there are 4 main LOX isoforms, 5-LOX, 8-LOX, 12-LOX, 15-LOX, constituting hydroperoxides with positional and stereo specificity. In the subsequent metabolic processes they provide significant cell signaling molecules and secondary messengers taking part in the development of inflammatory, tumorous and other diseases. Recent studies clarified the role of lipoxygenases in various diseases. The study of the structure and the active site of enzyme, preparation of recombinant forms with the targeted gene mutations have shown possibilities for better understanding the lipoxygenase role in various pathological processes. Searching for selective inhibitors of LOX isoenzymes is an active area of investigation. They can represent an important research tool or become a promising targeted therapy of a wide range of human diseases.
- MeSH
- Isoenzymes genetics classification MeSH
- Arachidonic Acid metabolism MeSH
- Humans MeSH
- Lipoxygenases * pharmacology chemistry classification MeSH
- Molecular Conformation MeSH
- Mutation MeSH
- Fatty Acids, Unsaturated metabolism MeSH
- Mammals MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
Wounding, one of the most intensive stresses influencing plants ontogeny and lifespan, can be induced by herbivory as well as by physical factors. Reactive oxygen species play indispensable role both in the local and systemic defense reactions which enable "reprogramming" of metabolic pathways to set new boundaries and physiological equilibrium suitable for survival. In our current study, we provide experimental evidence on the formation of singlet oxygen (1O2) after wounding of Arabidopsis leaves. It is shown that 1O2 is formed by triplet-triplet energy transfer from triplet carbonyls to molecular oxygen. Using lipoxygenase inhibitor catechol, it is demonstrated that lipid peroxidation is initiated by lipoxygenase. Suppression of 1O2 formation in lox2 mutant which lacks chloroplast lipoxygenase indicates that lipoxygenase localized in chloroplast is predominantly responsible for 1O2 formation. Interestingly, 1O2 formation is solely restricted to chloroplasts localized at the wounding site. Data presented in this study might provide novel insight into wound-induced signaling in the local defense reaction.
- MeSH
- Arabidopsis MeSH
- Phenotype MeSH
- Fluorescent Antibody Technique MeSH
- Microscopy, Confocal MeSH
- Lipoxygenase metabolism MeSH
- Lipoxygenases genetics MeSH
- Fatty Acids metabolism MeSH
- Molecular Imaging MeSH
- Mutation MeSH
- Arabidopsis Proteins genetics MeSH
- Wounds and Injuries metabolism MeSH
- Singlet Oxygen metabolism MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Geranyl flavones have been studied as compounds that potentially can be developed as anti-inflammatory agents. A series of natural geranylated flavanones was isolated from Paulownia tomentosa fruits, and these compounds were studied for their anti-inflammatory activity and possible mechanism of action. Two new compounds were characterized [paulownione C (17) and tomentodiplacone O (20)], and all of the isolated derivatives were assayed for their ability to inhibit cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX). The compounds tested showed variable degrees of activity, with several of them showing activity comparable to or greater than the standards used in COX-1, COX-2, and 5-LOX assays. However, only the compound tomentodiplacone O (20) showed more selectivity against COX-2 versus COX-1 when compared with ibuprofen. The ability of the test compounds to interact with the above-mentioned enzymes was supported by docking studies, which revealed the possible incorporation of selected test substances into the active sites of these enzymes. Furthermore, one of the COX/LOX dual inhibitors, diplacone (14) (a major geranylated flavanone of P. tomentosa), was studied in vitro to obtain a proteomic overview of its effect on inflammation in LPS-treated THP-1 macrophages, supporting its previously observed anti-inflammatory activity and revealing the mechanism of its anti-inflammatory effect.
- MeSH
- Anti-Inflammatory Agents chemistry isolation & purification pharmacology MeSH
- Arachidonate 5-Lipoxygenase metabolism MeSH
- Cyclooxygenase 1 metabolism MeSH
- Cyclooxygenase 2 metabolism MeSH
- Flavonoids chemistry isolation & purification pharmacology MeSH
- Cyclooxygenase 2 Inhibitors chemistry isolation & purification pharmacology MeSH
- Lipoxygenase Inhibitors chemistry isolation & purification pharmacology MeSH
- Magnoliopsida chemistry MeSH
- Molecular Structure MeSH
- Fruit chemistry MeSH
- Proteomics * MeSH
- Publication type
- Journal Article MeSH
Two new series of N-substituted indole derivatives 4a-l and 5a-h were synthesized. Their chemical structures were confirmed using spectroscopic tools including IR, (1)H NMR, (13)C NMR mass spectroscopy and elemental analyses. The results showed no significant cytotoxic activity on either cancer or normal human cells. Anti-inflammatory activity for all target compounds was evaluated in vitro. Compounds 5a-h were found to have better anti-inflammatory activity than 4a-l. The inhibitory activity of COX-2 and 5-LOX were tested for 5a-h. Three compounds, 5c, 5d and 5f showed excellent COX-2 inhibitory activity with IC50 ranging from 0.98 to 1.23 μM compared to the reference celecoxib (1.54 μM). These compounds had a reasonable selectivity index between 7.03 and 8.05. Additionally, p-methylbenzoyl derivative 5g (IC50 = 5.78 μM) had superior 5-LOX inhibitory activity, higher than quercetin. 5e was close to quercetin in its LOX inhibitory activity. Compounds 5a-h were docked inside the active site of COX-2 and 5-LOX enzymes.
- MeSH
- Anti-Inflammatory Agents chemical synthesis chemistry metabolism pharmacology MeSH
- Arachidonate 5-Lipoxygenase chemistry metabolism MeSH
- Cyclooxygenase 1 metabolism MeSH
- Cyclooxygenase 2 metabolism MeSH
- Indoles chemical synthesis chemistry metabolism pharmacology MeSH
- Cyclooxygenase 2 Inhibitors chemical synthesis chemistry metabolism pharmacology MeSH
- Lipoxygenase Inhibitors chemical synthesis chemistry metabolism pharmacology MeSH
- Catalytic Domain MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Antineoplastic Agents chemical synthesis chemistry metabolism pharmacology MeSH
- Drug Design * MeSH
- Schiff Bases chemistry MeSH
- Molecular Docking Simulation * MeSH
- Chemistry Techniques, Synthetic MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
