scholarly journals The glycosyltransferase UGT76E1 significantly contributes to 12-O-glucopyranosyl-jasmonic acid formation in wounded Arabidopsis thaliana leaves

2019 ◽  
Vol 294 (25) ◽  
pp. 9858-9872 ◽  
Author(s):  
Sven Haroth ◽  
Kirstin Feussner ◽  
Amélie A. Kelly ◽  
Krzysztof Zienkiewicz ◽  
Alaa Shaikhqasem ◽  
...  

Jasmonoyl-isoleucine (JA-Ile) is a phytohormone that orchestrates plant defenses in response to wounding, feeding insects, or necrotrophic pathogens. JA-Ile metabolism has been studied intensively, but its catabolism as a potentially important mechanism for the regulation of JA-Ile–mediated signaling is not well-understood. Especially the enzyme(s) responsible for specifically glycosylating 12-hydroxy-jasmonic acid (12-OH-JA) and thereby producing 12-O-glucopyranosyl-jasmonic acid (12-O-Glc-JA) is still elusive. Here, we used co-expression analyses of available Arabidopsis thaliana transcriptomic data, identifying four UDP-dependent glycosyltransferase (UGT) genes as wound-induced and 12-OH-JA–related, namely, UGT76E1, UGT76E2, UGT76E11, and UGT76E12. We heterologously expressed and purified the corresponding proteins to determine their individual substrate specificities and kinetic parameters. We then used an ex vivo metabolite-fingerprinting approach to investigate these proteins in conditions as close as possible to their natural environment, with an emphasis on greatly extending the range of potential substrates. As expected, we found that UGT76E1 and UGT76E2 are 12-OH-JA-UGTs, with UGT76E1 contributing a major in vivo UGT activity, as deduced from Arabidopsis mutants with abolished or increased UGT gene expression. In contrast, recombinant UGT76E11 acted on an unidentified compound and also glycosylated two other oxylipins, 11-hydroxy-7,9,13-hexadecatrienoic acid (11-HHT) and 13-hydroxy-9,11,15-octadecatrienoic acid (13-HOT), which were also accepted by recombinant UGT76E1, UGT76E2, and UGT76E12 enzymes. UGT76E12 glycosylated 12-OH-JA only to a low extent, but also accepted an artificial hydroxylated fatty acid and low amounts of kaempferol. In conclusion, our findings have elucidated the missing step in the wound-induced synthesis of 12-O-glucopyranosyl-jasmonic acid in A. thaliana.

2021 ◽  
pp. 2004149
Author(s):  
Sara Rolandsson Enes ◽  
Thomas H. Hampton ◽  
Jayita Barua ◽  
David H. McKenna ◽  
Claudia C. dos Santos ◽  
...  

BackgroundDespite increased interest in MSC-based cell therapies for the acute respiratory distress syndrome (ARDS), clinical investigations have not yet been successful and understanding of the potential in vivo mechanisms of MSC actions in ARDS remain limited. ARDS is driven by an acute severe innate immune dysregulation, often characterised by inflammation, coagulation, and cell injury. How this inflammatory microenvironment influences MSC functions remains to be determined.AimTo comparatively assess how the inflammatory environment present in ARDS lungs versus the lung environment present in healthy volunteers alters MSC behaviors.MethodsClinical grade human bone marrow-derived MSCs (hMSCs) were exposed to bronchoalveolar lavage fluid (BALF) samples obtained from ARDS patients or from healthy volunteers. Following exposure, hMSCs and their conditioned media were evaluated for a broad panel of relevant properties including viability, levels of expression of inflammatory cytokines, gene expression, cell surface HLA expression, and activation of coagulation and complement pathways.ResultsPro-inflammatory, pro-coagulant, and major histocompatibility complex (self recognition) related gene expression was markedly up-regulated in hMSCs exposed ex vivo to BALF obtained from healthy volunteers. In contrast, these changes were less apparent and often opposite in hMSCs exposed to ARDS BALF samples.ConclusionThese data provide new insights into how hMSCs behave in healthy versus inflamed lung environments strongly suggesting that the inflamed environment in ARDS induces hMSC responses potentially benefical for cell survival and actions. This further highlights the need to understand how different disease environments affect hMSC functions.


2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Liang Du ◽  
Jingwan Zhang ◽  
Alexander Clowes ◽  
David Dichek

Background Autogenous vein grafts are effective therapies for obstructive arterial disease. However, their long-term utility is limited by stenosis and occlusion. Genetic engineering of veins that prevents intimal hyperplasia and atherosclerosis could significantly improve the clinical utility of vein grafts. We recently reported that a helper-dependent adenoviral vector (HDAd) reduces atherosclerosis 4 wks after gene transfer in fat-fed rabbits and can express a therapeutic transgene (apo AI) in normal rabbit carotids for at least 48 wks. Use of HDAd for vein graft gene therapy will depend on achievement of similarly high and persistent transgene expression in grafted veins. Hypothesis We tested the hypothesis that Ad-mediated transgene expression in grafted veins (at an early time point) can be increased by varying the timing of gene transfer. Methods Rabbit external jugular veins were transduced by exposure to a beta galactosidase (b-gal)-expressing Ad: in situ either without (a) or with (b) immediate arterial grafting; c) ex vivo with grafting after overnight incubation with Ad; d) in vivo immediately after grafting and e) in vivo 4 wks after grafting (n = 6 - 19 veins/group). Transgene expression was measured in veins removed 3 d after Ad exposure by PCR quantitation of b-gal mRNA and by en-face planimetry of blue-stained area. Results B-gal transgene expression was higher in ungrafted veins than in veins grafted immediately after gene transfer (84 ± 17 vs 9.4 ± 2.0 arbitrary units (AU); P < 0.0001). Overnight incubation of veins with Ad increased gene expression ex vivo by 10-fold but neither this nor performing vector infusion immediately after grafting improved gene expression (11 ± 4.7 and 9.1 ± 1.8 AU; P > 0.9 for both vs immediately grafted veins). Delaying gene transfer until 4 wks after grafting significantly increased gene expression, to a level equivalent to transgene expression in ungrafted veins (61 ± 11 AU; P = 0.3 vs ungrafted veins). En face planimetry yielded similar results. Conclusions Exposure of a transduced vein to arterial blood flow is associated with significant loss of transgene expression. Transgene expression in grafted veins is significantly higher when gene transfer is performed 4 wks after exposure of the vein to arterial blood flow.


2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S9-S10
Author(s):  
Brooklyn McGrew ◽  
Aman Shrivastava ◽  
Philip Fernandes ◽  
Lubaina Ehsan ◽  
Yash Sharma ◽  
...  

Abstract Background Candidate markers for Crohn’s Disease (CD) may be identified via gene expression-based construction of metabolic networks (MN). These can computationally describe gene-protein-reaction associations for entire tissues and also predict the flux of reactions (rate of turnover of specific molecules via a metabolic pathway). Recon3D is the most comprehensive human MN to date. We used publicly available CD transcriptomic data along with Recon3D to identify metabolites as potential diagnostic and prognostic biomarkers. Methods Terminal ileal gene expression profiles (36,372 genes; 218 CD. 42 controls) from the RISK cohort (Risk Stratification and Identification of Immunogenetic and Microbial Markers of Rapid Disease Progression in Children with Crohn’s Disease) and their transcriptomic abundances were used. Recon3D was pruned to only include RISK dataset transcripts which determined metabolic reaction linkage with transcriptionally active genes. Flux balance analysis (FBA) was then run using RiPTiDe with context specific transcriptomic data to further constrain genes (Figure 1). RiPTiDe was independently run on transcriptomic data from both CD and controls. From the pruned and constricted MN obtained, reactions were extracted for further analysis. Results After applying the necessary constraints to modify Recon3D, 527 CD and 537 control reactions were obtained. Reaction comparison with a publicly available list of healthy small intestinal epithelial reactions (n=1282) showed an overlap of 80 CD and 84 control reactions. These were then further grouped based on their metabolic pathways. RiPTiDe identified context specific metabolic pathway activity without supervision and the percentage of forward, backward, and balanced reactions for each metabolic pathway (Figure 2). The metabolite concentrations in the small intestine was altered among CD patients. Notably, the citric acid cycle and malate-aspartate shuttle were affected, highlighting changes in mitochondrial metabolic pathways. This is illustrated by changes in the number of reactions at equilibrium between CD and control. Conclusions The results are relevant as cytosolic acetyl-CoA is needed for fatty acid synthesis and is obtained by removing citrate from the citric acid cycle. An intermediate removal from the cycle has significant cataplerotic effects. The malate-aspartate shuttle also allows electrons to move across the impermeable membrane in the mitochondria (fatty acid synthesis location). These findings are reported by previously published studies where gene expression for fatty acid synthesis is altered in CD patients along with mitochondrial metabolic pathway changes, resulting in altered cell homeostasis. In-depth analysis is currently underway with our work supporting the utility of potential metabolic biomarkers for CD diagnosis, management and improved care.


Author(s):  
Christian U Oeing ◽  
Seungho Jun ◽  
Sumita Mishra ◽  
Brittany Dunkerly-Eyring ◽  
Anna Chen ◽  
...  

Rationale: The mechanistic target of rapamycin complex-1 (mTORC1) controls metabolism and protein homeostasis, and is activated following ischemic reperfusion (IR) injury and by ischemic preconditioning (IPC). However, studies vary as to whether this activation is beneficial or detrimental, and its influence on metabolism after IR is little studied. A limitation of prior investigations is their use of broad gain/loss of mTORC1 function, mostly applied prior to ischemic stress. This can be circumvented by regulating one serine (S1365) on tuberous sclerosis complex (TSC2) to achieve bi-directional mTORC1 modulation but only with TCS2-regulated co-stimulation. Objective: We tested the hypothesis that reduced TSC2 S1365 phosphorylation protects the myocardium against IR and IPC by amplifying mTORC1 activity to favor glycolytic metabolism. Methods and Results: Mice with either S1365A (TSC2 SA ; phospho-null) or S1365E (TSC2 SE ; phosphomimetic) knock-in mutations were studied ex vivo and in vivo. In response to IR, hearts from TSC2 SA mice had amplified mTORC1 activation and improved heart function compared to WT and TSC2 SE hearts. The magnitude of protection matched IPC. IPC requited less S1365 phosphorylation, as TSC2 SE hearts gained no benefit and failed to activate mTORC1 with IPC. IR metabolism was altered in TSC2 SA , with increased mitochondrial oxygen consumption rate and glycolytic capacity (stressed/maximal extracellular acidification) after myocyte hypoxia-reperfusion. In whole heart, lactate increased and long-chain acyl-carnitine levels declined during ischemia. The relative IR protection in TSC2 SA was lost by lowering glucose in the perfusate by 36%. Adding fatty acid (palmitate) compensated for reduced glucose in WT and TSC2 SE but not TSC2 SA which had the worst post-IR function under these conditions. Conclusions: TSC2-S1365 phosphorylation status regulates myocardial substrate utilization, and its decline activates mTORC1 biasing metabolism away from fatty acid oxidation to glycolysis to confer protection against IR. This pathway is also engaged and reduced TSC2 S1365 phosphorylation required for effective IPC.


2004 ◽  
Vol 286 (4) ◽  
pp. H1461-H1470 ◽  
Author(s):  
Maya Khairallah ◽  
François Labarthe ◽  
Bertrand Bouchard ◽  
Gawiyou Danialou ◽  
Basil J. Petrof ◽  
...  

The availability of genetically modified mice requires the development of methods to assess heart function and metabolism in the intact beating organ. With the use of radioactive substrates and ex vivo perfusion of the mouse heart in the working mode, previous studies have documented glucose and fatty acid oxidation pathways. This study was aimed at characterizing the metabolism of other potentially important exogenous carbohydrate sources, namely, lactate and pyruvate. This was achieved by using 13C-labeling methods. The mouse heart perfusion setup and buffer composition were optimized to reproduce conditions close to the in vivo milieu in terms of workload, cardiac functions, and substrate-hormone supply to the heart (11 mM glucose, 0.8 nM insulin, 50 μM carnitine, 1.5 mM lactate, 0.2 mM pyruvate, 5 nM epinephrine, 0.7 mM oleate, and 3% albumin). The use of three differentially 13C-labeled carbohydrates and a 13C-labeled long-chain fatty acid allowed the quantitative assessment of the metabolic origin and fate of tissue pyruvate as well as the relative contribution of substrates feeding acetyl-CoA (pyruvate and fatty acids) and oxaloacetate (pyruvate) for mitochondrial citrate synthesis. Beyond concurring with the notion that the mouse heart preferentially uses fatty acids for energy production (63.5 ± 3.9%) and regulates its fuel selection according to the Randle cycle, our study reports for the first time in the mouse heart the following findings. First, exogenous lactate is the major carbohydrate contributing to pyruvate formation (42.0 ± 2.3%). Second, lactate and pyruvate are constantly being taken up and released by the heart, supporting the concept of compartmentation of lactate and glucose metabolism. Finally, mitochondrial anaplerotic pyruvate carboxylation and citrate efflux represent 4.9 ± 1.8 and 0.8 ± 0.1%, respectively, of the citric acid cycle flux and are modulated by substrate supply. The described 13C-labeling strategy combined with an experimental setup that enables continuous monitoring of physiological parameters offers a unique model to clarify the link between metabolic alterations, cardiac dysfunction, and disease development.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2360-2360
Author(s):  
Agata A Filip ◽  
Dorota Koczkodaj ◽  
Tomasz Kubiatowski ◽  
Ewa Wasik-Szczepanek ◽  
Anna Dmoszynska

Abstract Abstract 2360 Poster Board II-337 Introduction: Despite their longevity in vivo, CLL lymphocytes die rapidly when put to in vitro cultures, what proves that the resistance to apoptosis is not an intrinsic feature of leukemic cells, but depends on environmental signals. Recently it was shown that mononuclear cells from peripheral blood of CLL patients differentiate in vitro into large, adherent cells that grow in close contact with CLL lymphocytes. They were termed “nurselike cells” (NLCs), because they support leukemic lymphocyte survival in culture. The presence of the cells morphologically and phenotypically similar to NLCs was demonstrated in peripheral lymphatic organs of CLL patients. It may suggest their role in CLL lymphocytes protection in vivo and, as a consequence, point the new target in CLL treatment. Patients and Methods: The study included the group of 65 previously untreated CLL patients, 24 women and 41 men, aged from 36 to 86 yrs. 12 patients (18%) were diagnosed with stage 0 according to Rai, 15 patients (23%) with stage I, 30 patients (46%) with stage II, 5 patients (8%) with stage III and 3 patients (5%) with stage IV. Peripheral blood lymphocytes ex vivo were examined for CD14, CD38, BCL2 and ZAP70 expression by flow cytometry and for BCL2, SURVIVIN and ZAP70 gene expression by RT-PCR. TP53 gene status was assessed by FISH. Lymphocytes of 20 patients were assayed for apoptosis-related gene expression by means of cDNA macroarrays (Clontech). To generate NLCs, PB leukemic cells were cultured in vitro for 14 days on standard medium (RPMI 1640 with L-glutamine, 15% FCS, antibiotics/antimycotics; cell density 3 × 106/ml) and the outgrowth and number of NLCs was assessed in relation to clinical and hematological parameters. NLCs were identified morphologically and by CD31/VIMENTIN protein expression. Results: In 58 cases (89%) the outgrowth of NLCs was observed, while their number differed in cultures of the cells of different patients: in 49 cultures (84.5%) there were over 20 NLCs/mm2 (up to 52 NLCs/mm2), and in 9 cases (15.5%) less than 20 NLCs/mm2. Positive correlation was shown between NLC number and B2M serum level (p=0.044) and absolute monocyte count (p=0.019). Significantly higher NLC number was observed in case of patients with higher CD14+ cell number (p<0.0001) and higher SURVIVIN gene expression assessed by RT-PCR (p<0.0001) and macroarrays (p=0.013). We found no statistically significant relation of NLCs number and: the Rai stage of the disease, WBC, lymphocyte count, LDH serum level, BCL2, CD38 and ZAP70 expression and TP53 gene status. During the follow-up period of 6 years we observed the tendency for longer overall survival in patients that produce less than 20 NLCs/mm2 (fig. 1), but it was not statistically significant. Conclusions: The number of NLC cells obtained in vitro from PBL of CLL patients correlates with B2M serum level and SURVIVIN gene expression in CLL cells ex vivo. High B2M level is a marker of poor prognosis. SURVIVIN represents a family of IAP (Inhibitor of APoptosis) proteins. While rare in PBL of CLL patients, its expression is typical for proliferating leukemic cells pool in pseudofollicle microenvironment. SURVIVIN inhibits apoptosis by blocking caspase-3 and -7. Considering the protective role of NLC cells towards CLL lymphocytes in vitro, these results altogether with observed tendency to shorter survival of patients generating high NLCs number may prove the presence of supportive mechanisms exerted by NLCs in vivo. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2002 ◽  
Vol 100 (13) ◽  
pp. 4640-4648 ◽  
Author(s):  
Betty S. Pace ◽  
Gary L. White ◽  
George J. Dover ◽  
Michael S. Boosalis ◽  
Douglas V. Faller ◽  
...  

Orally bioactive compounds that induce γ globin gene expression at tolerable doses are needed for optimal treatment of the β-hemoglobinopathies. Short-chain fatty acids (SCFAs) of 2 to 6 carbons in length induce γ globin expression in animal models, and butyrate, phenylbutyrate, and valproate induce γ globin in human patients. The usefulness of these compounds, however, is limited by requirements for large doses because of their rapid metabolism and their tendency to inhibit cell proliferation, which limits the pool of erythroid progenitors in which γ globin can be induced. Selected short-chain fatty acid derivatives (SCFADs) were recently found to induce γ globin and to stimulate the proliferation of hematopoietic cells in vitro. These SCFADs are now evaluated in vivo in nonanemic transgenic mice containing the human β globin gene locus and in anemic phlebotomized baboons. In mice treated with a SCFAD once daily for 5 days, γ globin mRNA increased 2-fold, reticulocytes increased 3- to 7-fold, and hematocrit levels increased by 27%. Administration of 3 SCFADs in anemic baboons increased F-reticulocytes 2- to 15-fold over baseline and increased total hemoglobin levels by 1 to 2 g/dL per week despite ongoing significant daily phlebotomy. Pharmacokinetic studies demonstrated 90% oral bioavailability of 2 SCFADs, and targeted plasma levels were maintained for several hours after single oral doses equivalent to 10% to 20% of doses required for butyrate. These findings identify SCFADs that stimulate γ globin gene expression and erythropoiesis in vivo, activities that are synergistically beneficial for treatment of the β hemoglobinopathies and useful for the oral treatment of other anemias.


2017 ◽  
Vol 216 (7) ◽  
pp. 2217-2230 ◽  
Author(s):  
Gregoire Stik ◽  
Simon Crequit ◽  
Laurence Petit ◽  
Jennifer Durant ◽  
Pierre Charbord ◽  
...  

Extracellular vesicles (EVs) have been recently reported as crucial mediators in cell-to-cell communication in development and disease. In this study, we investigate whether mesenchymal stromal cells that constitute a supportive microenvironment for hematopoietic stem and progenitor cells (HSPCs) released EVs that could affect the gene expression and function of HSPCs. By taking advantage of two fetal liver–derived stromal lines with widely differing abilities to maintain HSPCs ex vivo, we demonstrate that stromal EVs play a critical role in the regulation of HSPCs. Both supportive and nonsupportive stromal lines secreted EVs, but only those delivered by the supportive line were taken up by HSPCs ex vivo and in vivo. These EVs harbored a specific molecular signature, modulated the gene expression in HSPCs after uptake, and maintained the survival and clonogenic potential of HSPCs, presumably by preventing apoptosis. In conclusion, our study reveals that EVs are an important component of the HSPC niche, which may have major applications in regenerative medicine.


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