scholarly journals Metabolic control of histone demethylase activity involved in plant response to high temperature

2021 ◽  
Author(s):  
Xiaoyun Cui ◽  
Yu Zheng ◽  
Yue Lu ◽  
Emmanuelle Issakidis-Bourguet ◽  
Dao-Xiu Zhou
Keyword(s):  
Metabolic Pathways ◽  
Gene Activation ◽  
Plant Response ◽  
Histone Demethylases ◽  
Loss Of Function ◽  
Oxidative Demethylation ◽  
Histone Lysine ◽  
Demethylase Activity ◽  
Histone H3k4 ◽  
The Impact

Abstract Jumonji (Jmj)-C domain proteins are histone lysine demethylases that require ferrous iron and alpha-ketoglutarate (or α-KG) as cofactors in the oxidative demethylation reaction. In plants, α-KG is produced by isocitrate dehydrogenases (ICDH) in different metabolic pathways. It remains unclear whether fluctuation of α-KG levels affects JmjC demethylase activity and epigenetic regulation of plant gene expression. In this work, we studied the impact of loss of function of the cytosolic ICDH (or cICDH) gene on the function of histone demethylases in Arabidopsis thaliana. Loss of cICDH resulted in increases of overall histone H3 lysine 4 trimethylation (H3K4me3) and enhanced mutation defects of the H3K4me3 demethylase gene JMJ14. Genetic analysis suggested that the cICDH mutation may affect the activity of other demethylases, including JMJ15 and JMJ18 that function redundantly with JMJ14 in the plant thermosensory response. Furthermore, we show that mutation of JMJ14 affected both the gene activation and repression programs of the plant thermosensory response and that JMJ14 and JMJ15 repressed a set of genes that are likely to play negative roles in the process. The results provide evidence that histone H3K4 demethylases are involved in the plant response to elevated ambient temperature.

scholarly journals A Gain-of-Function Screen Reveals Redundant ERF Transcription Factors Providing Opportunities for Resistance Breeding Toward the Vascular Fungal Pathogen Verticillium longisporum

2019 ◽  
Vol 32 (9) ◽  
pp. 1095-1109 ◽  
Author(s):  
Christian Fröschel ◽  
Tim Iven ◽  
Elisabeth Walper ◽  
Vanessa Bachmann ◽  
Christoph Weiste ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Fungal Pathogen ◽  
Gene Activation ◽  
Fungal Colonization ◽  
Ethylene Response Factor ◽  
Loss Of Function ◽  
Gain Of Function ◽  
P450 Monooxygenase ◽  
Verticillium Longisporum ◽  
The Impact

Verticillium longisporum is a vascular fungal pathogen leading to severe crop loss, particular in oilseed rape. Transcription factors (TF) are highly suited for genetic engineering of pathogen-resistant crops, as they control sets of functionally associated genes. Applying the AtTORF-Ex (Arabidopsis thaliana transcription factor open reading frame expression) collection, a simple and robust screen of TF-overexpressing plants was established displaying reduced fungal colonization. Distinct members of the large ethylene response factor (ERF) family, namely ERF96 and the six highly related subgroup IXb members ERF102 to ERF107, were identified. Whereas overexpression of these ERF significantly reduces fungal propagation, single loss-of-function approaches did not reveal altered susceptibility. Hence, this gain-of-function approach is particularly suited to identify redundant family members. Expression analyses disclosed distinct ERF gene activation patterns in roots and leaves, suggesting functional differences. Transcriptome studies performed on chemically induced ERF106 expression revealed an enrichment of genes involved in the biosynthesis of antimicrobial indole glucosinolates (IG), such as CYP81F2 (CYTOCHROME P450-MONOOXYGENASE 81F2), which is directly regulated by IXb-ERF via two GCC-like cis-elements. The impact of IG in restricting fungal propagation was further supported as the cyp81f2 mutant displayed significantly enhanced susceptibility. Taken together, this proof-of-concept approach provides a novel strategy to identify candidate TF that are valuable genetic resources for engineering or breeding pathogen-resistant crop plants.

scholarly journals ATP13A2 Regulates Cellular α-Synuclein Multimerization, Membrane Association, and Externalization

2021 ◽  
Vol 22 (5) ◽  
pp. 2689
Author(s):  
Jianmin Si ◽  
Chris Van den Haute ◽  
Evy Lobbestael ◽  
Shaun Martin ◽  
Sarah van Veen ◽  
...  
Keyword(s):  
Membrane Integrity ◽  
Ubiquitin Proteasome System ◽  
Regulatory Function ◽  
Membrane Association ◽  
Loss Of Function ◽  
Atypical Form ◽  
Polyamine Transport ◽  
Independent Functions ◽  
Ubiquitin Proteasome ◽  
The Impact

ATP13A2, a late endo-/lysosomal polyamine transporter, is implicated in a variety of neurodegenerative diseases, including Parkinson’s disease and Kufor–Rakeb syndrome, an early-onset atypical form of parkinsonism. Loss-of-function mutations in ATP13A2 result in lysosomal deficiency as a consequence of impaired lysosomal export of the polyamines spermine/spermidine. Furthermore, accumulating evidence suggests the involvement of ATP13A2 in regulating the fate of α-synuclein, such as cytoplasmic accumulation and external release. However, no consensus has yet been reached on the mechanisms underlying these effects. Here, we aimed to gain more insight into how ATP13A2 is linked to α-synuclein biology in cell models with modified ATP13A2 activity. We found that loss of ATP13A2 impairs lysosomal membrane integrity and induces α-synuclein multimerization at the membrane, which is enhanced in conditions of oxidative stress or exposure to spermine. In contrast, overexpression of ATP13A2 wildtype (WT) had a protective effect on α-synuclein multimerization, which corresponded with reduced αsyn membrane association and stimulation of the ubiquitin-proteasome system. We also found that ATP13A2 promoted the secretion of α-synuclein through nanovesicles. Interestingly, the catalytically inactive ATP13A2 D508N mutant also affected polyubiquitination and externalization of α-synuclein multimers, suggesting a regulatory function independent of the ATPase and transport activity. In conclusion, our study demonstrates the impact of ATP13A2 on α-synuclein multimerization via polyamine transport dependent and independent functions.

A Melanocortin-4 Receptor Agonist Induces Skin and Hair Pigmentation in Patients with Monogenic Mutations in the Leptin-Melanocortin Pathway

2021 ◽  
pp. 1-10
Author(s):  
Varvara Kanti ◽  
Lia Puder ◽  
Irina Jahnke ◽  
Philipp Maximilian Krabusch ◽  
Jan Kottner ◽  
...  
Keyword(s):  
Leptin Receptor ◽  
Skin Pigmentation ◽  
Gene Mutations ◽  
Continuous Treatment ◽  
Whole Body ◽  
Hair Color ◽  
Phase 2 ◽  
Loss Of Function ◽  
The Impact ◽  
Over Time

<b><i>Background and Objectives:</i></b> Gene mutations within the leptin-melanocortin signaling pathway lead to severe early-onset obesity. Recently, a phase 2 trial evaluated new pharmacological treatment options with the MC4R agonist <i>setmelanotide</i> in patients with mutations in the genes encoding proopiomelanocortin (POMC) and leptin receptor (LEPR). During treatment with <i>setmelanotide,</i> changes in skin pigmentation were observed, probably due to off-target effects on the closely related melanocortin 1 receptor (MC1R). Here, we describe in detail the findings of dermatological examinations and measurements of skin pigmentation during this treatment over time and discuss the impact of these changes on patient safety. <b><i>Methods:</i></b> In an investigator-initiated, phase 2, open-label pilot study, 2 patients with loss-of-function POMC gene mutations and 3 patients with loss-of-function variants in LEPR were treated with the MC4R agonist <i>setmelanotide</i>. Dermatological examination, dermoscopy, whole body photographic documentation, and spectrophotometric measurements were performed at screening visit and approximately every 3 months during the course of the study. <b><i>Results:</i></b> We report the results of a maximum treatment duration of 46 months. Skin pigmentation increased in all treated patients, as confirmed by spectrophotometry. During continuous treatment, the current results indicate that elevated tanning intensity levels may stabilize over time. Lips and nevi also darkened. In red-haired study participants, hair color changed to brown after initiation of <i>setmelanotide</i> treatment. <b><i>Discussion:</i></b> <i>Setmelanotide</i> treatment leads to skin tanning and occasionally hair color darkening in both POMC- and LEPR-deficient patients. No malignant skin changes were observed in the patients of this study. However, the results highlight the importance of regular skin examinations before and during MC4R agonist treatment.

scholarly journals Preservation of epoxyeicosatrienoic acid bioavailability prevents renal allograft dysfunction and cardiovascular alterations in kidney transplant recipients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thomas Duflot ◽  
Charlotte Laurent ◽  
Anne Soudey ◽  
Xavier Fonrose ◽  
Mouad Hamzaoui ◽  
...  
Keyword(s):  
Endothelial Function ◽  
Kidney Transplant ◽  
Plasma Levels ◽  
Renal Allograft ◽  
Transplant Recipients ◽  
Loss Of Function ◽  
Kidney Transplant Recipients ◽  
Allograft Dysfunction ◽  
Allograft Function ◽  
The Impact

AbstractThis study addressed the hypothesis that epoxyeicosatrienoic acids (EETs) synthesized by CYP450 and catabolized by soluble epoxide hydrolase (sEH) are involved in the maintenance of renal allograft function, either directly or through modulation of cardiovascular function. The impact of single nucleotide polymorphisms (SNPs) in the sEH gene EPHX2 and CYP450 on renal and vascular function, plasma levels of EETs and peripheral blood monuclear cell sEH activity was assessed in 79 kidney transplant recipients explored at least one year after transplantation. Additional experiments in a mouse model mimicking the ischemia–reperfusion (I/R) injury suffered by the transplanted kidney evaluated the cardiovascular and renal effects of the sEH inhibitor t-AUCB administered in drinking water (10 mg/l) during 28 days after surgery. There was a long-term protective effect of the sEH SNP rs6558004, which increased EET plasma levels, on renal allograft function and a deleterious effect of K55R, which increased sEH activity. Surprisingly, the loss-of-function CYP2C9*3 was associated with a better renal function without affecting EET levels. R287Q SNP, which decreased sEH activity, was protective against vascular dysfunction while CYP2C8*3 and 2C9*2 loss-of-function SNP, altered endothelial function by reducing flow-induced EET release. In I/R mice, sEH inhibition reduced kidney lesions, prevented cardiac fibrosis and dysfunction as well as preserved endothelial function. The preservation of EET bioavailability may prevent allograft dysfunction and improve cardiovascular disease in kidney transplant recipients. Inhibition of sEH appears thus as a novel therapeutic option but its impact on other epoxyfatty acids should be carefully evaluated.

scholarly journals OP0277-PARE METABERN, THE EUROPEAN REFERENCE NETWORK FOR RARE HEREDITARY DISEASES: STRUCTURE, OBJECTIVES, METABOLIC RMDS AND THE ROLES OF EUROPEAN PATIENT ADVOCACY GROUPS (EPAGS)

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 168.2-168
Author(s):  
L. Wagner ◽  
S. Sestini ◽  
C. Brown ◽  
A. Finglas ◽  
R. Francisco ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Health Care ◽  
Social Science ◽  
Metabolic Pathways ◽  
Metabolic Disorders ◽  
Clinical Care ◽  
Single Point ◽  
Link Type ◽  
The Impact

Background:Inborn metabolic disorders (IMDs) currently encompass more than 1,500 diseases with new ones still to be identified1. Each of them is characterised by a genetic defect affecting a metabolic pathway. Only few of them have curative treatments, that target the respective metabolic pathway. Commonly, treatment examples include diet, substrate reduction therapies, enzyme replacement therapies, gene therapy and biologicals, enabling IMD-patient now to survive to adulthood. About 30 % of all IMDs involve the musculoskeletal system and are here referred to as rare metabolic RMDs. Generally, IMDs are very heterogenous with respect to symptoms and severity, often being systemic and affecting more children than adults. Thus, challenges include certified advanced training of adult metabolic experts, standardised transition plans, social support and development of therapies for diseases that do not have any cure yet.Objectives:Introduction of MetabERN, its structure and objectives, highlighting on the unique features and challenges of metabolic RMDs and describing the involvement of patient representation in MetabERN.Methods:MetabERN is stratified in 7 subnetworks (SNW) according to the respective metabolic pathways and 9 work packages (WP), including administration, dissemination, guidelines, virtual counselling framework, research/clinical trials, continuity of care, education and patient involvement. The patient board involves a steering committee and single point of contacts for each subnetwork and work package, respectively2. Projects include identifying the need of implementing social science to assess the psycho-socio-economic burden of IMDs, webinars on IMDs and their transition as well as surveys on the impact of COVID-193 on IMD-patients and health care providers (HCPs), social assistance for IMD-patients and analysing the transition landscape within Europe.Results:The MetabERN structure enables bundling of expertise, capacity building and knowledge transfer for faster diagnosis and better health care. Rare metabolic RMDs are present in all SNWs that require unique treatments according to their metabolic pathways. Implementation of social science to assess the psycho-socio-economic burden of IMDs is still underused. Involvement of patient representatives is essential for a holistic healthcare not only focusing on clinical care, but also on the quality of life for IMD-patients. Surveys identified unmet needs of patient care, patients having little information on national support systems and structural deficits of healthcare systems to ensure HCP can provide adequate clinical care during transition phases. These results are collected by MetabERN and forwarded to the Directorate-General for Health and Food Safety (DG SANTE) of the European Commission (EC) to be addressed further.Conclusion:MetabERN offers an infrastructure of virtual healthcare for patients with IMDs. Thus, in collaboration with ERN ReCONNET, MetabERN can assist in identifying rare metabolic disorders of RMDs to shorten the odyssey of diagnosis and advise on their respective therapies. On the other hand, MetabERN can benefit from EULAR’s longstanding experience regarding issues affecting the quality of life, all RMD patients are facing, such as pain, stiffness, fatigue, rehabilitation, maintaining work and disability claims.References:[1]IEMbase - Inborn Errors of Metabolism Knowledgebase http://www.iembase.org/ (accessed Jan 29, 2021).[2]MetabERN: European Refence Network for Hereditary Metabolic Disorders https://metab.ern-net.eu/ (accessed Jan 29, 2021).[3]Lampe, C.; Dionisi-Vici, C.; Bellettato, C. M.; Paneghetti, L.; van Lingen, C.; Bond, S.; Brown, C.; Finglas, A.; Francisco, R.; Sestini, S.; Heard, J. M.; Scarpa, M.; MetabERN collaboration group. The Impact of COVID-19 on Rare Metabolic Patients and Healthcare Providers: Results from Two MetabERN Surveys. Orphanet J. Rare Dis.2020, 15 (1), 341. https://doi.org/10.1186/s13023-020-01619-x.Acknowledgements:The authors thank the MetabERN collaboration group, the single point of contacts (SPOC) of the MetabERN patient board and the Transition Project Working Group (TPWG)Disclosure of Interests:None declared

scholarly journals Codon harmonization reduces amino acid misincorporation in bacterially expressed P. falciparum proteins and improves their immunogenicity

AMB Express ◽  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Neeraja Punde ◽  
Jennifer Kooken ◽  
Dagmar Leary ◽  
Patricia M. Legler ◽  
Evelina Angov
Keyword(s):  
Protein Structure ◽  
Amino Acid ◽  
Codon Usage ◽  
Dna Sequences ◽  
Structural Integrity ◽  
Host Cells ◽  
Loss Of Function ◽  
Species Specific ◽  
And Function ◽  
The Impact

Abstract Codon usage frequency influences protein structure and function. The frequency with which codons are used potentially impacts primary, secondary and tertiary protein structure. Poor expression, loss of function, insolubility, or truncation can result from species-specific differences in codon usage. “Codon harmonization” more closely aligns native codon usage frequencies with those of the expression host particularly within putative inter-domain segments where slower rates of translation may play a role in protein folding. Heterologous expression of Plasmodium falciparum genes in Escherichia coli has been a challenge due to their AT-rich codon bias and the highly repetitive DNA sequences. Here, codon harmonization was applied to the malarial antigen, CelTOS (Cell-traversal protein for ookinetes and sporozoites). CelTOS is a highly conserved P. falciparum protein involved in cellular traversal through mosquito and vertebrate host cells. It reversibly refolds after thermal denaturation making it a desirable malarial vaccine candidate. Protein expressed in E. coli from a codon harmonized sequence of P. falciparum CelTOS (CH-PfCelTOS) was compared with protein expressed from the native codon sequence (N-PfCelTOS) to assess the impact of codon usage on protein expression levels, solubility, yield, stability, structural integrity, recognition with CelTOS-specific mAbs and immunogenicity in mice. While the translated proteins were expected to be identical, the translated products produced from the codon-harmonized sequence differed in helical content and showed a smaller distribution of polypeptides in mass spectra indicating lower heterogeneity of the codon harmonized version and fewer amino acid misincorporations. Substitutions of hydrophobic-to-hydrophobic amino acid were observed more commonly than any other. CH-PfCelTOS induced significantly higher antibody levels compared with N-PfCelTOS; however, no significant differences in either IFN-γ or IL-4 cellular responses were detected between the two antigens.

scholarly journals Clinical, Genetics, and Bioinformatic Characterization of Mutations Affecting an Essential Region of PLS3 in Patients with BMND18

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Ting Chen ◽  
Haiying Wu ◽  
Chenxi Zhang ◽  
Jiarong Feng ◽  
Linqi Chen ◽  
...  
Keyword(s):  
Novel Mutation ◽  
Homology Modelling ◽  
Gene Sequencing ◽  
Bioinformatic Analysis ◽  
Actin Binding ◽  
Clinical Genetics ◽  
Loss Of Function ◽  
Mineral Density ◽  
Trait Locus ◽  
The Impact

Background. Bone mineral density quantitative trait locus 18 (BMND18, OMIM #300910) is a type of early-onset osteogenesis imperfecta (OI) caused by loss-of-function mutations in the PLS3 gene, which encodes plastin-3, a key protein in the formation of actin bundles throughout the cytoskeleton. Here, we report a patient with PLS3 mutation caused BMND18 and evaluated all the reported disease-causing mutations by bioinformatic analysis. Methods. Targeted gene sequencing was performed to find the disease-causing mutation in our patient. Bioinformatic analyses mainly including homology modelling and molecular dynamics stimulation were conducted to explore the impact of the previously reported mutations on plastin-3. Results. Gene sequencing showed a novel nonsense mutation (c.745G > T, p.E249X), which locates at a highly conserved region containing residues p.240–266 (LOOP-1) in the PLS3 gene. Further bioinformatic analyses of the previously reported mutations revealed that LOOP-1 is predicted to physically connect the calponin-homology 1 (CH1) and CH2 domains of the ABD1 fragment and spatially locates within the interface of ABD1 and ABD2. It is crucial to the conformation transition and actin-binding function of plastin-3. Conclusions. This report identified a novel mutation that truncates the PLS3 gene. Moreover, bioinformatic analyses of the previous reported mutations in PLS3 gene lead us to find a critical LOOP-1 region of plastin-3 mutations at which may be detrimental to the integral conformation of plastin-3 and thus affect its binding to actin filament.

SARS-Coronavirus 2, A Metabolic Reprogrammer: A Review in the Context of the Possible Therapeutic Strategies

2021 ◽  
Vol 22 ◽  
Author(s):  
Poornima Gopi ◽  
TR Anju ◽  
Vinod Soman Pillai ◽  
Mohanan Veettil
Keyword(s):  
Virus Infection ◽  
Host Cell ◽  
Metabolic Pathways ◽  
Inflammatory Responses ◽  
Membrane Lipid ◽  
Therapeutic Strategies ◽  
Metabolic Reprogramming ◽  
Multiple Organs ◽  
The Cross ◽  
The Impact

: Novel coronavirus, SARS-CoV-2 is advancing at a staggering pace to devastate the health care system and foster the concerns over public health. In contrast to the past outbreaks, coronaviruses aren’t clinging themselves as a strict respiratory virus. Rather, becoming a multifaceted virus, it affects multiple organs by interrupting a number of metabolic pathways leading to significant rates of morbidity and mortality. Following infection they rigorously reprogram multiple metabolic pathways of glucose, lipid, protein, nucleic acid and their metabolites to extract adequate energy and carbon skeletons required for their existence and further molecular constructions inside a host cell. Although the mechanism of these alterations are yet to be known, the impact of these reprogramming is reflected in the hyper inflammatory responses, so called cytokine storm and the hindrance of host immune defence system. The metabolic reprogramming during SARS-CoV-2 infection needs to be considered while devising therapeutic strategies to combat the disease and its further complication. The inhibitors of cholesterol and phospholipids synthesis and cell membrane lipid raft of the host cell can, to a great extent, control the viral load and further infection. Depletion of energy source by inhibiting the activation of glycolytic and hexoseamine biosynthetic pathway can also augment the antiviral therapy. The cross talk between these pathways also necessitates the inhibition of amino acid catabolism and tryptophan metabolism. A combinatorial strategy which can address the cross talks between the metabolic pathways might be more effective than a single approach and the infection stage and timing of therapy will also influence the effectiveness of the antiviral approach. We herein focus on the different metabolic alterations during the course of virus infection that help to exploit the cellular machinery and devise a therapeutic strategy which promotes resistance to viral infection and can augment body’s antivirulence mechanisms. This review may cast the light into the possibilities of targeting altered metabolic pathways to defend virus infection in a new perspective.

Abstract 14849: Gender Differences in Impact of CYP2C19 Polymorphism and Low Grade Inflammation on Coronary Spasm in Patients with Vasospastic Angina (VSA)

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Tomonori Akasaka ◽  
Seiji Hokimoto ◽  
Noriaki Tabata ◽  
Kenji Sakamoto ◽  
Kenichi Tsujita ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Artery Spasm ◽  
Coronary Spasm ◽  
Control Group ◽  
Low Grade ◽  
Cyp2c19 Genotype ◽  
Loss Of Function ◽  
Hs Crp ◽  
The Impact ◽  
Low Grade Inflammation

Background: Several cytochrome P450 (CYP) enzyme families have been identified in extra hepatic tissues such as heart, vasculature, kidney, and lung. CYP2C19 localized in vascular smooth muscle and endothelium contributes to the regulation of vascular tone and homeostasis. However, it is unknown whether CYP2C19 genotype is associated with the vascular tonus in patients with VSA. The aim of this study was to examine the impact of CYP2C19 genotype on coronary artery spasm in patients with VSA. Methods: We examined the distribution of CYP2C19 genotype in patients with VSA (n=129) who were diagnosed by intra-coronary acetylcholine infusion test and healthy subjects (n=455) as control group. CYP2C19 genotypes were divided into 3 groups; (1) CYP2C19*1/*1: EM, (2) one loss-of-function allele (*1/*2, *1/*3: IM), and (3) two loss-of-function alleles (*2/*2, *2/*3, *3/*3: PM). Moreover, we measured the level of high-sensitive CRP (hs-CRP) as a degree of low glade inflammation in each group. Results: The ratios of CYP2C19 genotype (EM, IM, and PM) were 30, 42, and 28% in VSA group, and 32, 49, and 19% in control group. In short, PM frequency was significantly higher in VSA than in control (28% vs 19%, P=0.026). In VSA group, the ratios of CYP2C19 genotype were 36, 44, and 20% in male, and 20, 39, and 41% in female, respectively. Briefly, the PM frequency was significantly higher in female than in male (41% vs 20%, P<0.001). Moreover, the level of hs-CRP was significantly higher in VSA group than in control group (0.17±0.367 vs 0.10.±0.240, P=0.02). When patients were stratified by gender, the level of hs-CRP was significantly higher in VSA group in female (0.11±0.198 vs 0.06±0.105, P=0.031) and male (0.20±0.438 vs 0.12±0.277, P=0.044). Multivariate analysis for coronary spasm indicated high age, hypertension, and high level of hs-CRP as predictive factors among all subjects. PM is a predictive factor for coronary spasm in female group only (OR3.1, 95%RI 1.525-6.317, P=0.002), but not in male (OR0.829, 95%RI 0.453-1.518, P=0.543). Conclusion: The CYP2C19 two loss-of-function alleles (PM) and low grade inflammation may be associated with pathophysiology of coronary artery spasm and the regulation of coronary tonus, especially in female.

scholarly journals Liver X Receptor Nuclear Receptors Are Transcriptional Regulators of Dendritic Cell Chemotaxis

2018 ◽  
Vol 38 (10) ◽  
Author(s):  
Susana Beceiro ◽  
Attila Pap ◽  
Zsolt Czimmerer ◽  
Tamer Sallam ◽  
Jose A. Guillén ◽  
...  
Keyword(s):  
Nuclear Receptors ◽  
Low Density Lipoprotein ◽  
Myeloid Cells ◽  
Density Lipoprotein ◽  
Loss Of Function ◽  
Transcriptional Responses ◽  
Cd38 Expression ◽  
The Impact

ABSTRACTThe liver X receptors (LXRs) are ligand-activated nuclear receptors with established roles in the maintenance of lipid homeostasis in multiple tissues. LXRs exert additional biological functions as negative regulators of inflammation, particularly in macrophages. However, the transcriptional responses controlled by LXRs in other myeloid cells, such as dendritic cells (DCs), are still poorly understood. Here we used gain- and loss-of-function models to characterize the impact of LXR deficiency on DC activation programs. Our results identified an LXR-dependent pathway that is important for DC chemotaxis. LXR-deficient mature DCs are defective in stimulus-induced migrationin vitroandin vivo. Mechanistically, we show that LXRs facilitate DC chemotactic signaling by regulating the expression of CD38, an ectoenzyme important for leukocyte trafficking. Pharmacological or genetic inactivation of CD38 activity abolished the LXR-dependent induction of DC chemotaxis. Using the low-density lipoprotein receptor-deficient (LDLR−/−) LDLR−/−mouse model of atherosclerosis, we also demonstrated that hematopoietic CD38 expression is important for the accumulation of lipid-laden myeloid cells in lesions, suggesting that CD38 is a key factor in leukocyte migration during atherogenesis. Collectively, our results demonstrate that LXRs are required for the efficient emigration of DCs in response to chemotactic signals during inflammation.

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