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Scientific Data Nov 2020Structural studies of challenging targets such as G protein-coupled receptors (GPCRs) have accelerated during the last several years due to the development of new...
Structural studies of challenging targets such as G protein-coupled receptors (GPCRs) have accelerated during the last several years due to the development of new approaches, including small-wedge and serial crystallography. Here, we describe the deposition of seven datasets consisting of X-ray diffraction images acquired from lipidic cubic phase (LCP) grown microcrystals of two human GPCRs, Cysteinyl leukotriene receptors 1 and 2 (CysLTR and CysLTR), in complex with various antagonists. Five datasets were collected using small-wedge synchrotron crystallography (SWSX) at the European Synchrotron Radiation Facility with multiple crystals under cryo-conditions. Two datasets were collected using X-ray free electron laser (XFEL) serial femtosecond crystallography (SFX) at the Linac Coherent Light Source, with microcrystals delivered at room temperature into the beam within LCP matrix by a viscous media microextrusion injector. All seven datasets have been deposited in the open-access databases Zenodo and CXIDB. Here, we describe sample preparation and annotate crystallization conditions for each partial and full datasets. We also document full processing pipelines and provide wrapper scripts for SWSX and SFX data processing.
Topics: Crystallization; Cysteine; Humans; Leukotrienes; Receptors, G-Protein-Coupled; Synchrotrons; X-Ray Diffraction
PubMed: 33184270
DOI: 10.1038/s41597-020-00729-2 -
Drug Discovery Today Feb 2019The underlying pathology of Alzheimer's disease (AD) is complex and includes, besides amyloid beta (Aβ) plaque depositions and neurofibrillary tangles, brain atrophy... (Review)
Review
The underlying pathology of Alzheimer's disease (AD) is complex and includes, besides amyloid beta (Aβ) plaque depositions and neurofibrillary tangles, brain atrophy and neurodegeneration, neuroinflammation, impaired neurogenesis, vascular and blood-brain barrier (BBB) disruptions, neurotransmitter disbalances, and others. Here, we hypothesize that such complex pathologies can only be targeted efficiently through pleiotropic approaches. One interesting drug target is the leukotriene pathway, which mediates various aspects of AD pathology. Approaching this pathway at different levels with genetic and pharmacological tools demonstrated beneficial outcomes in several in vivo studies using different mouse models of AD. Here, we review the current literature on the leukotriene signaling pathway as a target for drug development in AD.
Topics: Alzheimer Disease; Animals; Blood-Brain Barrier; Cell Death; Drug Repositioning; Humans; Leukotrienes; Neurogenesis; Neurons; Signal Transduction
PubMed: 30240876
DOI: 10.1016/j.drudis.2018.09.008 -
The American Journal of Clinical... Jan 2005Cocoa products are sources of flavan-3-ols, which have attracted interest regarding cardiovascular health. This review provides a survey of our research on the effects... (Review)
Review
Cocoa products are sources of flavan-3-ols, which have attracted interest regarding cardiovascular health. This review provides a survey of our research on the effects of cocoa polyphenols on leukotriene and nitric oxide (NO) metabolism and on myeloperoxidase-induced modification of LDL. Because intake of flavonoid-rich chocolate by human subjects was reported to decrease the plasma concentrations of proinflammatory cysteinyl leukotrienes, we assessed whether cocoa polyphenols inhibited human 5-lipoxygenase, the key enzyme of leukotriene synthesis. (-)-Epicatechin and other cocoa flavan-3-ols proved to be inhibitory at the enzyme level. This action may confer antileukotriene action in vivo. In a double-blind crossover study, 20 individuals at risk for cardiovascular diseases received cocoa beverages with high or low contents of flavan-3-ols. NO-dependent, flow-mediated dilation of the brachial artery and concentrations of nitroso compounds in plasma were measured, and it was shown that ingestion of the high-flavanol coca drink but not the low-flavanol cocoa drink significantly increased plasma concentrations of nitroso compounds and flow-mediated dilation of the brachial artery. Therefore, ingested flavonoids may reverse endothelial dysfunction through enhancement of NO bioactivity. Oxidative modification of LDL appears to be crucial for atherogenesis, and one of the mediators is the proinflammatory proatherogenic enzyme myeloperoxidase. Micromolar concentrations of (-)-epicatechin or other flavonoids were found to suppress lipid peroxidation in LDL induced by myeloperoxidase in the presence of physiologically relevant concentrations of nitrite, an NO metabolite. Adverse effects of NO metabolites, such as nitrite and peroxynitrite, were thus attenuated.
Topics: Animals; Antioxidants; Cacao; Enzyme Inhibitors; Flavonoids; Humans; Leukotrienes; Lipid Peroxidation; Lipoxygenase; Nitric Oxide; Peroxidase
PubMed: 15640495
DOI: 10.1093/ajcn/81.1.304S -
Allergy Oct 2011Leukotriene B(4) (LTB(4)) and cysteinyl leukotrienes (cysLTs) are important immune mediators, often found concomitantly at sites of inflammation. Although some of the...
BACKGROUND
Leukotriene B(4) (LTB(4)) and cysteinyl leukotrienes (cysLTs) are important immune mediators, often found concomitantly at sites of inflammation. Although some of the leukotriene-mediated actions are distinctive (e.g., bronchial constriction for cysLTs), many activities such as leukocyte recruitment to tissues and amplification of inflammatory responses are shared by both classes of leukotrienes.
OBJECTIVE
We used human monocytes to characterize leukotriene-specific signaling, gene expression signatures, and functions and to identify interactions between LTB(4)- and cysLTs-induced pathways.
METHODS
Responsiveness to leukotrienes was assessed using oligonucleotide microarrays, real-time PCR, calcium mobilization, kinase activation, and chemotaxis assays.
RESULTS
Human monocytes were found to express mRNA for high- and low-affinity LTB(4) receptors, BLT(1) and BLT(2), but signal predominantly through BLT(1) in response to LTB(4) stimulation as shown using selective agonists, inhibitors, and gene knock down experiments. LTB(4) acting through BLT(1) coupled to G-protein α inhibitory subunit activated calcium signaling, p44/42 mitogen-activated protein kinase, gene expression, and chemotaxis. Twenty-seven genes, including immediate early genes (IEG), transcription factors, cytokines, and membrane receptors were significantly up-regulated by LTB(4). LTB(4) and LTD(4) had similar effects on signaling, gene expression, and chemotaxis indicating redundant cell activation pathways but costimulation with both lipid mediators was additive for many monocyte functions.
CONCLUSION
Leukotriene B(4) and LTD(4) display both redundant and cooperative effects on intracellular signaling, gene expression, and chemotaxis in human monocytes. These findings suggest that therapies targeting either leukotriene alone may be less effective than approaches directed at both.
Topics: Calcium; Chemotaxis; GTP-Binding Protein alpha Subunits, Gi-Go; Gene Expression Regulation; Humans; Leukotriene B4; Leukotriene D4; Mitogen-Activated Protein Kinases; Monocytes; Receptors, Leukotriene B4; Signal Transduction
PubMed: 21605126
DOI: 10.1111/j.1398-9995.2011.02647.x -
Journal of Bone and Mineral Research :... Aug 2023Leukotrienes (LTs) are derived from arachidonic acid metabolism by the 5-lipoxygenase (5-LO) enzyme. The production of LTs is stimulated in the pathogenesis of...
Leukotrienes (LTs) are derived from arachidonic acid metabolism by the 5-lipoxygenase (5-LO) enzyme. The production of LTs is stimulated in the pathogenesis of rheumatoid arthritis (RA), osteoarthritis, and periodontitis, with a relevant contribution to bone resorption. However, its role in bone turnover, particularly the suppression of bone formation by modulating the function of osteoclasts and osteoblasts, remains unclear. We investigated the effects of LTs on bone metabolism and their impact on osteogenic differentiation and osteoclastogenesis using a 5-LO knockout (KO) mouse model. Results from micro-computed tomography (μCT) analysis of femur from 8-week-old 5-LO-deficient mice showed increased cortical bone and medullary region in females and males and decreased trabecular bone in females. In the vertebra, we observed increased marrow area in both females and males 5-LO KO and decreased trabecular bone only in females 5-LO KO. Immunohistochemistry (IHC) analysis showed higher levels of osteogenic markers tissue-nonspecific alkaline phosphatase (TNAP) and osteopontin (OPN) and lower expression of osteoclastogenic marker tartrate-resistant acid phosphatase (TRAP) in the femurs of 5-LO KO mice versus wild-type (WT). Alkaline phosphatase activity and mineralization assay results showed that the 5-LO absence enhances osteoblasts differentiation and mineralization but decreases the proliferation. Alkaline phosphatase (ALP), Bglap, and Sp7 gene expression were higher in 5-LO KO osteoblasts compared to WT cells. Eicosanoids production was higher in 5-LO KO osteoblasts except for thromboxane 2, which was lower in 5-LO-deficient mice. Proteomic analysis identified the downregulation of proteins related to adenosine triphosphate (ATP) metabolism in 5-LO KO osteoblasts, and the upregulation of transcription factors such as the adaptor-related protein complex 1 (AP-1 complex) in long bones from 5-LO KO mice leading to an increased bone formation pattern in 5-LO-deficient mice. We observed enormous differences in the morphology and function of osteoclasts with reduced bone resorption markers and impaired osteoclasts in 5-LO KO compared to WT osteoclasts. Altogether, these results demonstrate that the absence of 5-LO is related to the greater osteogenic profile. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
Topics: Male; Female; Mice; Animals; Osteogenesis; Alkaline Phosphatase; X-Ray Microtomography; Proteomics; Osteoclasts; Osteoblasts; Bone Resorption; Cell Differentiation; Mice, Knockout; Leukotrienes
PubMed: 37314430
DOI: 10.1002/jbmr.4867 -
PloS One 2022Cysteinyl leukotriene receptor 1 (CysLTR1) is a G protein-coupled receptor for the inflammatory lipid mediators cysteinyl leukotrienes, which are involved in smooth...
Cysteinyl leukotriene receptor 1 (CysLTR1) is a G protein-coupled receptor for the inflammatory lipid mediators cysteinyl leukotrienes, which are involved in smooth muscle constriction, vascular permeability, and macrophage chemokine release. The Cysltr1 gene encoding CysLTR1 is expressed in the macrophage lineage, including osteoclasts, and the CysLTR1 antagonist Montelukast has been shown to suppress the formation of osteoclasts. However, it currently remains unclear whether CysLTR1 is involved in osteoclast differentiation and bone loss. Therefore, to clarify the role of CysLTR1 in osteoclastogenesis and pathological bone loss, we herein generated CysLTR1 loss-of-function mutant mice by disrupting the cysltr1 gene using the CRISPR-Cas9 system. These mutant mice had a frameshift mutation resulting in a premature stop codon (Cysltr1 KO) or an in-frame mutation causing the deletion of the first extracellular loop (Cysltr1Δ105). Bone marrow macrophages (BMM) from these mutant mice lost the intracellular flux of calcium in response to leukotriene D4, indicating that these mutants completely lost the activity of CysLTR1 without triggering genetic compensation. However, disruption of the Cysltr1 gene did not suppress the formation of osteoclasts from BMM in vitro. We also demonstrated that the CysLTR1 antagonist Montelukast suppressed the formation of osteoclasts without functional CysLTR1. On the other hand, disruption of the Cysltr1 gene partially suppressed the formation of osteoclasts stimulated by leukotriene D4 and did not inhibit that by glutathione, functioning as a substrate in the synthesis of cysteinyl leukotrienes. Disruption of the Cysltr1 gene did not affect ovariectomy-induced osteoporosis or lipopolysaccharide-induced bone resorption. Collectively, these results suggest that the CysLT-CysLTR1 axis is dispensable for osteoclast differentiation in vitro and pathological bone loss, while the leukotriene D4-CysTR1 axis is sufficient to stimulate osteoclast formation. We concluded that the effects of glutathione and Montelukast on osteoclast formation were independent of CysLTR1.
Topics: Female; Mice; Animals; Osteoclasts; Leukotriene D4; Bone Resorption; Leukotrienes; Glutathione
PubMed: 36395281
DOI: 10.1371/journal.pone.0277307 -
Frontiers in Cellular and Infection... 2023Leishmaniasis is a neglected tropical parasitic disease with few approved medications. Cutaneous leishmaniasis (CL) is the most frequent form, responsible for 0.7 - 1.0...
Leishmaniasis is a neglected tropical parasitic disease with few approved medications. Cutaneous leishmaniasis (CL) is the most frequent form, responsible for 0.7 - 1.0 million new cases annually worldwide. Leukotrienes are lipid mediators of inflammation produced in response to cell damage or infection. They are subdivided into leukotriene B4 (LTB) and cysteinyl leukotrienes LTC4 and LTD4 (Cys-LTs), depending on the enzyme responsible for their production. Recently, we showed that LTB could be a target for purinergic signaling controlling infection; however, the importance of Cys-LTs in the resolution of infection remained unknown. Mice infected with are a model of CL infection and drug screening. We found that Cys-LTs control infection in susceptible (BALB/c) and resistant (C57BL/6) mouse strains. , Cys-LTs significantly diminished the infection index in peritoneal macrophages of BALB/c and C57BL/6 mice. , intralesional treatment with Cys-LTs reduced the lesion size and parasite loads in the infected footpads of C57BL/6 mice. The anti-leishmanial role of Cys-LTs depended on the purinergic P2X7 receptor, as infected cells lacking the receptor did not produce Cys-LTs in response to ATP. These findings suggest the therapeutic potential of LTB4 and Cys-LTs for CL treatment.
Topics: Mice; Animals; Mice, Inbred C57BL; Leukotrienes; Leishmaniasis, Cutaneous; Cysteine; Leukotriene B4; Leishmaniasis
PubMed: 37377641
DOI: 10.3389/fcimb.2023.1192800 -
The Journal of Allergy and Clinical... Jul 2021The 3 cysteinyl leukotrienes (cysLTs), leukotriene (LT) C (LTC), LTD, and LTE, have different biologic half-lives, cellular targets, and receptor specificities. CysLTR...
BACKGROUND
The 3 cysteinyl leukotrienes (cysLTs), leukotriene (LT) C (LTC), LTD, and LTE, have different biologic half-lives, cellular targets, and receptor specificities. CysLTR binds LTC and LTDin vitro with similar affinities, but it displays a marked selectivity for LTCin vivo. LTC, but not LTD, strongly potentiates allergen-induced pulmonary eosinophilia in mice through a CysLTR-mediated, platelet- and IL-33-dependent pathway.
OBJECTIVE
We sought to determine whether LTD functionally antagonizes LTC signaling at CysLTR.
METHODS
We used 2 different in vivo models of CysLTR-dependent immunopathology, as well as ex vivo activation of mouse and human platelets.
RESULTS
LTC-induced CD62P expression; HMGB1 release; and secretions of thromboxane A, CXCL7, and IL-33 by mouse platelets were all were blocked by a selective CysLTR antagonist and inhibited by LTD. These effects did not depend on CysLTR. Inhaled LTD blocked LTC-mediated potentiation of ovalbumin-induced eosinophilic inflammation; recruitment of platelet-adherent eosinophils; and increases in IL-33, IL-4, IL-5, and IL-13 levels in lung tissue. In contrast, the effect of administration of LTE, the preferred ligand for CysLTR, was additive with LTC. The administration of LTD to Ptges mice, which display enhanced LTC synthesis similar to that in aspirin-exacerbated respiratory disease, completely blocked the physiologic response to subsequent lysine-aspirin inhalation challenges, as well as increases in levels of IL-33, type 2 cytokines, and biochemical markers of mast cell and platelet activation.
CONCLUSION
The conversion of LTC to LTD may limit the duration and extent of potentially deleterious signaling through CysLTR, and it may contribute to the therapeutic properties of desensitization to aspirin in aspirin-exacerbated respiratory disease.
Topics: Animals; Asthma; Blood Platelets; Cysteine; Cytokines; Leukotriene C4; Leukotriene D4; Leukotriene E4; Leukotrienes; Lung; Male; Mice; Mice, Inbred C57BL; Platelet Activation; Pulmonary Eosinophilia; Receptors, Leukotriene
PubMed: 33285161
DOI: 10.1016/j.jaci.2020.10.041 -
Mediators of Inflammation 2017Cysteinyl leukotrienes (CysLTs) are potent lipid mediators widely known for their actions in asthma and in allergic rhinitis. Accumulating data highlights their... (Review)
Review
Cysteinyl leukotrienes (CysLTs) are potent lipid mediators widely known for their actions in asthma and in allergic rhinitis. Accumulating data highlights their involvement in a broader range of inflammation-associated diseases such as cancer, atopic dermatitis, rheumatoid arthritis, and cardiovascular diseases. The reported elevated levels of CysLTs in acute and chronic brain lesions, the association between the genetic polymorphisms in the LTs biosynthesis pathways and the risk of cerebral pathological events, and the evidence from animal models link also CysLTs and brain diseases. This review will give an overview of how far research has gone into the evaluation of the role of CysLTs in the most prevalent neurodegenerative disorders (ischemia, Alzheimer's and Parkinson's diseases, multiple sclerosis/experimental autoimmune encephalomyelitis, and epilepsy) in order to understand the underlying mechanism by which they might be central in the disease progression.
Topics: Animals; Arthritis, Rheumatoid; Cardiovascular Diseases; Central Nervous System Diseases; Cysteine; Dermatitis, Atopic; Humans; Leukotrienes; Neurodegenerative Diseases
PubMed: 28607533
DOI: 10.1155/2017/3454212 -
Clinical Cancer Research : An Official... Nov 2019Here, we examined the role of leukotrienes, well-known inflammatory mediators, in the tumorigenesis of hedgehog pathway-associated medulloblastoma, and tested the...
PURPOSE
Here, we examined the role of leukotrienes, well-known inflammatory mediators, in the tumorigenesis of hedgehog pathway-associated medulloblastoma, and tested the efficacies of antagonists of leukotriene biosynthesis in medulloblastoma treatment. We examined the leukotriene levels in medulloblastoma cells by ELISA. We next tested whether leukotriene synthesis in medulloblastoma cells relied on activation of hedgehog pathway, or the presence of hedgehog ligand secreted by astrocytes. We then investigated whether leukotriene mediated hedgehog-induced Nestin expression in tumor cells. The functions of leukotriene in tumor cell proliferation and tumor growth in medulloblastoma were determined through knocking down 5-lipoxygenase (a critical enzyme for leukotriene synthesis) by shRNAs, or using 5-lipoxygenase-deficient mice. Finally, the efficacies of antagonists of leukotriene synthesis in medulloblastoma treatment were tested and .
RESULTS
Leukotriene was significantly upregulated in medulloblastoma cells. Increased leukotriene synthesis relied on hedgehog ligand secreted by astrocytes, a major component of medulloblastoma microenvironment. Leukotriene stimulated tumor cells to express Nestin, a cytoskeletal protein essential for medulloblastoma growth. Genetic blockage of leukotriene synthesis dramatically suppressed medulloblastoma cell proliferation and tumor growth . Pharmaceutical inhibition of leukotriene synthesis markedly repressed medulloblastoma cell proliferation, but had no effect on proliferation of normal neuronal progenitors. Moreover, antagonists of leukotriene synthesis exhibited promising tumor inhibitory efficacies on drug-resistant medulloblastoma.
CONCLUSIONS
Our findings reveal a novel signaling pathway that is critical for medulloblastoma cell proliferation and tumor progression, and that leukotriene biosynthesis represents a promising therapeutic target for medulloblastoma treatment.
Topics: Animals; Arachidonate 5-Lipoxygenase; Astrocytes; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Disease Progression; Gene Expression Regulation, Neoplastic; Hedgehog Proteins; Humans; Leukotrienes; Medulloblastoma; Mice; Mice, Knockout; RNA, Small Interfering; Signal Transduction
PubMed: 31300449
DOI: 10.1158/1078-0432.CCR-18-3549