5-Lipoxygenase (5-LO) catalyzes the early steps of leukotriene (LT) biosynthesis, making it an attractive target for anti-inflammatory drug development. This study provides a more detailed evaluation of the molecular mechanisms and pharmacological effects of litreol (CI), a natural compound from the Anacardiaceae family, along with its synthetic derivatives (CS, AS, and AI). The synthesis and biological evaluation of litreol analogs have already been previously published. Therefore, the aim of this article is to further explore their mechanisms of action, providing a more thorough investigation into their effects on 5-LO. Using both isolated human recombinant 5-LO in cell-free systems and cell-based assays, we evaluated the impact of the synthesized compounds on 5-LO product formation. Among them, CI and CS emerged as potent inhibitors, exhibiting IC50 values of 0.26 μM and 0.80 μM in neutrophils, and 0.06 μM and 0.15 μM in cell-free assays, respectively. Notably, CI exhibited 2.5- to 3-fold greater potency compared to its hydrogenated analogue, CS. Both compounds also showed inhibitory activity against 12-lipoxygenase (12-LO) with IC50 of 3.15 and 5.10 μM, respectively. Moreover, CI prevented the 5-LO/FLAP protein interaction and blocked both ERK-1/2 and p38 MAP kinase-dependent pathways required for 5-LO activation. Conversely, AS and AI derivatives did not show significant 5-LO inhibitory effects. Computational studies revealed that the differing binding modes and stability of CI and CS at the allosteric site of 5-LO explain their varying inhibitory effects. CI forms a stronger interaction network, supporting its higher potency, while CS shows greater flexibility and weaker interactions, correlating with lower activity. Additionally, the free catechol group is essential for activity, as its acetylation leads to loss of function. Overall, our findings highlight CI as a promising 5-LO inhibitor, in intact human leukocytes accounting for a novel potent anti-inflammatory compound.

Inflammation resolution is governed by specialized pro-resolving mediators (SPM), mainly formed from omega-3 polyunsaturated fatty acids (n-3 PUFA) by lipoxygenases (LOX), which terminate inflammatory processes and facilitate healing and tissue repair. Promoting endogenous SPM formation, besides therapeutic SPM application, is an innovative concept for intervention in inflammatory diseases, achievable by allosteric 15-LOX activation. Here, targeted screening of the 29 most frequently applied anti-inflammatory natural products using lipid mediator metabololipidomics uncovered the acylphloroglucinols hyperforin, arzanol, garcinol, Myrtucommulone A and the lignan magnolol as potent 15-LOX activators to elicit robust SPM production in resting human M2-like macrophages. Simultaneous n-3 PUFA supplementation synergistically enhanced SPM formation in these M2-like macrophages, most strikingly with magnolol. Comprehensive targeted metabololipidomics in activated human polymorphonuclear leukocytes, monocytes, and M1-/M2-like macrophages revealed shifts from pro-inflammatory cyclooxygenase (COX) and 5-LOX products to pro-resolving 15-LOX products by magnolol and acylphloroglucinols. Finally, using zymosan-induced peritonitis in mice, application of a magnolol/n-3 PUFA combination confirmed synergistic SPM elevation in vivo. Together, we established an approach based on synergism of natural allosteric 15-LOX activators and supplemented n-3 PUFA to accomplish SPM-based resolution pharmacology.

Since the discovery of graphene in 2004, there has been rapid progress in research on two-dimensional (2D) material’s potential applications with significant impact. Efforts to bring 2D materials closer to industrial production, quality assessment, and standardization still need to be expanded upon. This remains challenging because sophisticated analytics techniques are required to analyze a limited amount of material with high variability due to differences in the synthesis process and the lack of a clear standard for comparing results. Modern methods can evaluate domain size, surface coverage, defects, dopants, mobility, and photoluminescence parameters. Still, it is challenging to understand the structure–property relationship due to external influences such as adsorbates and strain, which can alter results. To address this problem, the Graphene Flagship project conducted an extensive benchmarking study of monolayer molybdenum disulfide grown through chemical vapor deposition by various groups. The study employed a variety of techniques to characterize the material, including optical and transmission electron microscopy, Raman spectroscopy, photoluminescence, X-ray photoelectron spectroscopy, and capacitance-voltage measurements. Herein, we present the results of this comprehensive study and the correlation between various methods

Unresolved inflammation, due to unfavorable imbalances between pro-inflammatory and pro-resolving mediators, leads to chronic inflammatory pathologies that are often sex-biased and regulated by sex hormones, including inflammatory bowel disease. Lipid mediators (LM) produced from polyunsaturated fatty acids by various lipoxygenases (LOX) and cyclooxygenases govern all stages of inflammation, i.e., the initiation and progression by pro-inflammatory eicosanoids and its resolution by specialized pro-resolving mediators (SPM). Here, we reveal sex-specific differences in murine experimental colitis with male preponderance, which was abolished by sex hormone deprivation using gonadectomy, and this correlated to the levels of inflammation-relevant mediators in the colon. Oral dextran sodium sulfate administration caused more severe colon inflammation in male CD-1 mice than in female counterparts during the acute phase. Colitis in males yielded higher colonic cytokine/chemokine levels but lower 12-/15-LOX-derived LM including SPM compared to female animals in the resolving phase. Sex hormone deprivation in male mice by orchidectomy ameliorated colitis and impaired pro-inflammatory cytokine/chemokine levels but elevated 12-/15-LOX products including SPM, thus abolishing the observed sex differences. Conversely, ovariectomy impaired the levels of those LM that dominated in females and that were increased in males after gonadectomy. Our findings suggest that male sex hormones promote the development of colitis connected to the biosynthesis of inflammatory cytokines, chemokines, and certain LM, especially pro-resolving 12-/15-LOX products that appear to be suppressed in the male colon due to androgens.

Haspin is an emerging, but rather unexplored, divergent kinase involved in tumor growth by regulating the mitotic phase. In this paper, the in-silico design, synthesis, and biological characterization of a new series of substituted indoles acting as potent Haspin inhibitors are reported. The synthesized derivatives have been evaluated by FRET analysis, showing very potent Haspin inhibition. Then, a comprehensive in-cell investigation highlighted compounds 47 and 60 as the most promising inhibitors. These compounds were challenged for their synergic activity with paclitaxel in 2D and 3D cellular models, demonstrating a twofold improvement of the paclitaxel antitumor activity. Compound 60 also showed remarkable selectivity when tested in a panel of 70 diverse kinases. Finally, in-silico studies provided new insight about the chemical requirements useful to develop new Haspin inhibitors. Biological results, together with the drug-likeness profile of 47 and 60, make these derivatives deserving further studies.

5-Lipoxygenase (LO) catalyzes the first steps in the formation of pro-inflammatory leukotrienes (LT) that are pivotal lipid mediators contributing to allergic reactions and inflammatory disorders. Based on its key role in LT biosynthesis, 5-LO is an attractive drug target, demanding for effective and selective inhibitors with efficacy in vivo, which however, are still rare. Encouraged by the recent identification of the catechol 4-(3,4-dihydrox-yphenyl)dibenzofuran 1 as 5-LO inhibitor, simple structural modifications were made to yield even more effective and selective catechol derivatives. Within this new series, the two most potent compounds 3,4-dihy-droxy-3 '-phenoxybiphenyl (6b) and 2-(3,4-dihydroxyphenyl)benzo[b]thiophene (6d) potently inhibited human 5-LO in cell-free (IC50 6b and 6d = 20 nM) and cell-based assays (IC50 6b = 70 nM, 6d = 60 nM). Inhibition of 5 -LO was reversible, unaffected by exogenously added substrate arachidonic acid, and not primarily mediated via radical scavenging and antioxidant activities. Functional 5-LO mutants expressed in HEK293 cells were still prone to inhibition by 6b and 6d, and docking simulations revealed distinct binding of the catechol moiety to 5 -LO at an allosteric site. Analysis of 5-LO nuclear membrane translocation and intracellular Ca2+ mobilization revealed that these 5-LO-activating events are hardly affected by the catechols. Importantly, the high inhibitory potency of 6b and 6d was confirmed in human blood and in a murine zymosan-induced peritonitis model in vivo. Our results enclose these novel catechol derivatives as highly potent, novel type inhibitors of 5-LO with high selectivity and with marked effectiveness under pathophysiological conditions.

The application of a multi-step scientific workflow revealed an unprecedented class of PGE2/leukotriene biosynthesis inhibitors with in vivo activity. Specifically, starting from a combinatorial virtual library of ∼4.2 × 105 molecules, a small set of compounds was identified for the synthesis. Among these, four novel 2-aminoacyl-1,3,4-thiadiazole derivatives (3, 6, 7, and 9) displayed marked anti-inflammatory properties in vitro by strongly inhibiting PGE2 biosynthesis, with IC50 values in the nanomolar range. The hit compounds also efficiently interfered with leukotriene biosynthesis in cell-based systems and modulated IL-6 and PGE2 biosynthesis in a lipopolysaccharide-stimulated J774A.1 macrophage cell line. The most promising compound 3 showed prominent in vivo anti-inflammatory activity in a mouse model, with efficacy comparable to that of dexamethasone, attenuating zymosan-induced leukocyte migration in mouse peritoneum with considerable modulation of the levels of typical pro-/anti-inflammatory cytokines.

The study of two-dimensional (2D) materials has gained significant attention due to their potential use in electronic, spintronic, and optoelectronics applications. Transition metal dichalcogenides (TMDs)[1], a type of 2D material, are particularly interesting because they have a bandgap that changes from indirect to direct as their thickness decreases from bulk to monolayer[2]. Tungsten disulphide (WS 2 )[3] is of particular interest due to its direct bandgap in the visible range, making it suitable for electronics and optoelectronics applications. Therefore, it is important to control the growth process to obtain high-quality WS 2 with desirable electronic and optical properties using chemical vapor deposition (CVD) growth for mass production of commercial devices.

Tungsten disulfide (WS 2 ) possesses attractive optical and electronic properties, which make it a promising candidate for a wide range of applications. However, upon growth it exhibits an intrinsic variety of defects, affecting its electronic and optical characteristics. This study focuses on the control of dielectric properties of WS 2 via defect density engineering. In particular, we investigate atomically thin WS 2 , grown via liquid phase chemical vapour deposition (LiP-CVD). By tuning the growth parameters, we can obtain WS 2 in different shapes and defect distribution, that are characterized by using optical spectroscopy, photoelectron spectroscopy, and Kelvin probe force microscopy. Our findings reveal the chemical nature of defects in WS 2 and their significant impact on the crystal’s optical properties. By gaining a deeper understanding of the microscopic nature of defects in WS 2 , this research provides a crucial contribution towards the development of a defect-controlled technology to tailor the dielectric environment in 2D crystals.

Single-layer molybdenum ditelluride (MoTe2) has attracted attention due to the smaller energy difference between the semiconducting (1H) and semimetallic (1T') phases with respect to other two-dimensional transition metal dichalcogenides (TMDs). Understanding the phenomenon of polymorphism between these structural phases is of great fundamental and practical importance. In this paper, we report a 1H to 1T' phase transition occurring during the chemical vapor deposition (CVD) synthesis of single-layer MoTe2 at 730 °C. The transformation originates at the heterocontact between monoclinic and hexagonal crystals and progresses to either yield a partial or complete 1H to 1T' phase transition. Microscopic and spectroscopic analyses of the MoTe2 crystals reveal the presence of Te vacancies and mirror twin boundaries (MTB) domains in the hexagonal phase. The experimental observations and theoretical simulations indicate that the combination of heterocontact formation and Te vacancies are relevant triggering mechanisms in the observed transformation. By advancing in the understanding and controlling of the direct synthesis of lateral 1T'/1H heterostructures, this work contributes to the development of MoTe2-based electronic and optoelectronic devices with low contact resistance.

The opto‐electronic properties of semiconducting 2D materials can be flexibly manipulated by engineering the atomic‐scale environment. This can be done by including 2D materials in tailored van der Waals (vdW) stacks, whose optical response is a function of the number and the type of adjacent 2D layers. This work reports a systematic investigation of the dielectric function of 2D semiconducting WS 2 in various stacking configurations: monolayer, 3R/2H homobilayer, and WS 2 /MoS 2 heterobilayer. Reliable, Kramers–Kronig‐consistent dielectric functions are obtained for WS 2 in each configuration by means of spectroscopic ellipsometry (SE) and related parametric optical modeling in a wide spectral range (1.55–3.10 eV). The results of SE are combined with photoluminescence and absorbance spectra to identify the spectral position of the main excitonic features in WS 2 , which manifest sizable redshifts depending on the stacking configuration. These results represent a consistent reference set for the dielectric function of WS 2 in vdW stacking configurations of particular interest for the scientific and technological field, and can be fruitfully exploited for reliable predictions of the optical response of WS 2 ‐containing systems.

Hexagonal boron nitride (hBN), sometimes referred to as white graphene, receives growing interest in the scientific community, especially when combined into van der Waals (vdW) homo- and heterostacks, in which novel and interesting phenomena may arise. hBN is also commonly used in combination with two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDCs). The realization of hBN-encapsulated TMDC homo- and heterostacks can indeed offer opportunities to investigate and compare TMDC excitonic properties in various stacking configurations. In this work, we investigate the optical response at the micrometric scale of mono- and homo-bilayer WS2grown by chemical vapor deposition and encapsulated between two single layers of hBN. Imaging spectroscopic ellipsometry is exploited to extract the local dielectric functions across one single WS2flake and detect the evolution of excitonic spectral features from monolayer to bilayer regions. Exciton energies undergo a redshift by passing from hBN-encapsulated single layer to homo-bilayer WS2, as also confirmed by photoluminescence spectra. Our results can provide a reference for the study of the dielectric properties of more complex systems where hBN is combined with other 2D vdW materials into heterostructures and are stimulating towards the investigation of the optical response of other technologically-relevant heterostacks.

Cannabinoids are phytochemicals from cannabis with anti-inflammatory actions in immune cells. Lipid mediators (LM), produced from polyunsaturated fatty acids (PUFA), are potent regulators of the immune response and impact all stages of inflammation. How cannabinoids influence LM biosynthetic networks is unknown. Here, we reveal cannabidiol (CBD) as a potent LM class-switching agent that stimulates the production of specialized pro-resolving mediators (SPMs) but suppresses pro-inflammatory eicosanoid biosynthesis. Detailed metabololipidomics analysis in human monocyte-derived macrophages showed that CBD (i) upregulates exotoxin-stimulated generation of SPMs, (ii) suppresses 5-lipoxygenase (LOX)-mediated leukotriene production, and (iii) strongly induces SPM and 12/15-LOX product formation in resting cells by stimulation of phospholipase A2-dependent PUFA release and through Ca2+-independent, allosteric 15-LOX-1 activation. Finally, in zymosan-induced murine peritonitis, CBD increased SPM and 12/15-LOX products and suppressed pro-inflammatory eicosanoid levels in vivo. Switching eicosanoid to SPM production is a plausible mode of action of CBD and a promising inflammation-resolving strategy.

Glucocorticoids (GC) are potent anti- inflammatory agents, broadly used to treat acute and chronic inflammatory diseases, e.g., critically ill COVID-19 patients or patients with chronic inflammatory bowel diseases. GC not only limit inflammation but also promote its resolution although the underlying mechanisms are obscure. Here, we reveal reciprocal regulation of 15- lipoxygenase (LOX) isoform expression in human monocyte/ macrophage lineages by GC with respective consequences for the biosynthesis of special-ized proresolving mediators (SPM) and their 15- LOX- derived monohydroxylated pre-cursors (mono- 15 -OH). Dexamethasone robustly up- regulated pre-mRNA, mRNA, and protein levels of ALOX15B/15-LOX-2 in blood monocyte-derived macrophage (MDM) phenotypes, causing elevated SPM and mono-15-OH production in inflammatory cell types. In sharp contrast, dexamethasone blocked ALOX15/15-LOX-1 expression and impaired SPM formation in proresolving M2-MDM. These dexamethasone actions were mimicked by prednisolone and hydrocortisone but not by progesterone, and they were counteracted by the GC receptor (GR) antagonist RU486. Chromatin immu-noprecipitation (ChIP) assays revealed robust GR recruitment to a putative enhancer region within intron 3 of the ALOX15B gene but not to the transcription start site. Knockdown of 15-LOX-2 in M1-MDM abolished GC- induced SPM formation and mono-15-OH production. Finally, ALOX15B/15-LOX-2 upregulation was evident in human monocytes from patients with GC- treated COVID-19 or patients with IBD. Our findings may explain the proresolving GC actions and offer opportunities for optimizing GC pharmacotherapy and proresolving mediator production.

Background and Purpose Celastrol (CS) is a major active ingredient of the Chinese/Asian herb Tripterygium wilfordii that is frequently used as phytomedicine to treat inflammation and autoimmune diseases. We showed before that short-term exposure to CS (1 µM) favorably impacts the biosynthesis of inflammation-related lipid mediators (LM) in human polarized macrophages by modulating the activities of different lipoxygenases (LOXs). However, whether CS regulates the expression of LOXs and other related LM-biosynthetic enzymes during macrophage polarization is unknown. Here, we investigated how CS affects LM-biosynthetic enzyme expression on the protein level and studied concomitant LM signature profiles during polarization of human monocyte-derived macrophages (MDM) towards M1- and M2-like phenotypes. Methods and Results We used LM metabololipidomics to study the long-term effects of CS on LM profile signatures after manipulation of human monocyte-derived macrophages (MDM) during polarization. Exposure of MDM to low concentrations of CS (ie, 0.2 µM) during polarization to an inflammatory M1 phenotype potently suppressed the formation of pro-inflammatory cyclooxygenase (COX)- and 5-LOX-derived LM, especially prostaglandin (PG)E2. Notably, gene and enzyme expression of COX-2 and microsomal PGE2 synthase (mPGES)-1 as well as M1 markers were strongly decreased by CS during M1-MDM polarization, along with impaired activation of nuclear factor-κB and p38 mitogen-activated protein kinase. During IL-4-induced M2 polarization, CS decreased the capacity of the resulting M2-MDM to generate pro-inflammatory COX and 5-LOX products as well but it also reduced the formation of 12/15-LOX products and specialized pro-resolving mediators, without affecting the levels of liberated fatty acid substrates. Conclusion Depending on the timing and concentration, CS not only favorably affects LOX activities in macrophages but also the expression of LM-biosynthetic enzymes during macrophage polarization connected to changes of inflammation-related LM which might be of relevance for potential application of CS to treat inflammatory disorders.

The design of multitarget drugs represents a promising strategy in medicinal chemistry and seems particularly suitable for the discovery of anti-inflammatory drugs. Here, we describe the identification of an indoline-based compound inhibiting both 5-lipoxygenase (5-LOX) and soluble epoxide hydrolase (sEH). In silico analysis of an in-house library identified nine compounds as potential 5-LOX inhibitors. Enzymatic and cellular assays revealed the indoline derivative 43 as a notable 5-LOX inhibitor, guiding the design of new analogues. These compounds underwent extensive in vitro investigation revealing dual 5-LOX/sEH inhibitors, with 73 showing the most promising activity (IC50s of 0.41 ± 0.01 and 0.43 ± 0.10 μM for 5-LOX and sEH, respectively). When challenged in vivo in zymosan-induced peritonitis and experimental asthma in mice, compound 73 showed remarkable anti-inflammatory efficacy. These results pave the way for the rational design of 5-LOX/sEH dual inhibitors and for further investigation of their potential use as anti-inflammatory agents.

The combination of metallic nanostructures with two-dimensional transition metal dichalcogenides is an efficient way to make the optical properties of the latter more appealing for opto-electronic applications. In this work, we investigate the optical properties of monolayer WS2 flakes grown by chemical vapour deposition and transferred onto a densely-packed array of plasmonic Au nanoparticles (NPs). The optical response was measured as a function of the thickness of a dielectric spacer intercalated between the two materials and of the system temperature, in the 75–350 K range. We show that a weak interaction is established between WS2 and Au NPs, leading to temperature- and spacer-thickness-dependent coupling between the localized surface plasmon resonance of Au NPs and the WS2 exciton. We suggest that the closely-packed morphology of the plasmonic array promotes a high confinement of the electromagnetic field in regions inaccessible by the WS2 deposited on top. This allows the achievement of direct contact between WS2 and Au while preserving a strong connotation of the properties of the two materials also in the hybrid system.

Macrophages are the primary human host cells of intracellular Mycobacterium tuberculosis (M.tb) infection, where the magnitude of inflammatory reactions is crucial for determining the outcome of infection. Previously, we showed that the anti-inflammatory drug sulfasalazine (SASP) significantly reduced the M.tb bactericidal burden and histopathological inflammation in mice. Here, we asked which genes in human inflammatory macrophages are affected upon infection with M.tb and how would potential changes impact the functional state of macrophages. We used a flow cytometry sorting system which can distinguish the dead and alive states of M.tb harbored in human monocyte-derived macrophages (MDM). We found that the expression of cyclooxygenase-2 and microsomal prostaglandin E2 synthase (mPGES)-1 increased significantly in tagRFP+ MDM which were infected with alive M.tb. After exposure of polarized M1-MDM to M.tb (H37Rv strain)-conditioned medium (MTB-CM) or to the M.tb-derived 19-kD antigen, the production of PGE2 and pro-inflammatory cytokines increased 3- to 4-fold. Upon treatment of M1-MDM with SASP, the MTB-CM-induced expression of COX-2 and the release of COX products and cytokines decreased. Elevation of PGE2 in M1-MDM upon MTB-CM stimulation and modulation by SASP correlated with the activation of the NF-κB pathway. Together, infection of human macrophages by M.tb strongly induces COX-2 and mPGES-1 expression along with massive PGE2 formation which is abrogated by the anti-inflammatory drug SASP.

Specialized pro‐resolving mediators (SPM), primarily produced in innate immune cells, exert crucial bioactions for resolving inflammation. Among various lipoxygenases (LOX), 15‐LOX‐1 is key for SPM biosynthesis, but cellular activation principles of 15‐LOX‐1 are unexplored. It was shown that 3‐ O ‐acetyl‐11‐keto‐ β ‐boswellic acid (AKBA) shifts 5‐LOX regiospecificity from 5‐ to 12‐lipoxygenation products. Here, it is demonstrated that AKBA additionally activates cellular 15‐LOX‐1 via an allosteric site accomplishing robust SPM formation in innate immune cells, particularly in M2 macrophages. Compared to ionophore, AKBA‐induced LOX activation is Ca 2+ ‐ and phosphorylation‐independent, with modest induction of 5‐LOX products. AKBA docks into a groove between the catalytic and regulatory domains of 15‐LOX‐1 interacting with R98; replacement of R98 by alanine abolishes AKBA‐induced 15‐LOX product formation in HEK293 cells. In zymosan‐induced murine peritonitis, AKBA strikingly elevates SPM levels and promotes inflammation resolution. Together, targeted allosteric modulation of LOX activities governs SPM formation and offers new concepts for inflammation resolution pharmacotherapy.