Expression profiles of organogenesis-related genes over the time course of one-step de novo shoot organogenesis from intact seedlings of kohlrabi

AbstractCross-talk between phytohormones and sugars is intensely involved in plant metabolism, growth and regeneration. We documented alterations in cytokinin (CK) homeostasis in four developmental stages during de novo shoot organogenesis (DNSO) of kohlrabi (Brassica oleracea var. gongylodes cv. Vienna Purple) seedlings induced by exogenous CKs, trans-zeatin (transZ) and thidiazuron (TDZ), added together with elevated sucrose concentration (6% and 9%). Significant impact of CK and sucrose treatment and their interaction was recorded in all investigated stages, including plantlet development before calli formation (T1 and T2), calli formation (T3) and shoot regeneration (T4). Results showed remarkable increase in total CK levels for transZ treatment, particularly with 9% sucrose. This trend was observed for all physiological and structural groups of CKs. Application of TDZ contributed to little or no increase in CK levels regardless of sucrose concentration. Analysis of expression profiles of organogenesis-related genes involved in auxin transport, CK response, shoot apical meristem formation and cell division revealed that higher sugar concentration significantly downregulated the analysed genes, particularly in T3. This continued on TDZ, but transZ induced an opposite effect with 9% sucrose in T4, increasing gene activity. Our results demonstrated that phytohormone metabolism might be triggered by sucrose signalling in kohlrabi DNSO.

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Arabidopsis 4-COUMAROYL-COA LIGASE 8 contributes to the biosynthesis of the benzenoid ring of coenzyme Q in peroxisomes

Biochemical Journal ◽

10.1042/bcj20190688 ◽

2019 ◽

Vol 476 (22) ◽

pp. 3521-3532

Author(s):

Eric Soubeyrand ◽

Megan Kelly ◽

Shea A. Keene ◽

Ann C. Bernert ◽

Scott Latimer ◽

...

Keyword(s):

Oxidative Metabolism ◽

Time Course ◽

Reverse Genetics ◽

De Novo ◽

Coenzyme Q ◽

Control Level ◽

Wild Type ◽

Fluorescent Reporters ◽

Coa Ligase ◽

Peroxisomal Targeting

Plants have evolved the ability to derive the benzenoid moiety of the respiratory cofactor and antioxidant, ubiquinone (coenzyme Q), either from the β-oxidative metabolism of p-coumarate or from the peroxidative cleavage of kaempferol. Here, isotopic feeding assays, gene co-expression analysis and reverse genetics identified Arabidopsis 4-COUMARATE-COA LIGASE 8 (4-CL8; At5g38120) as a contributor to the β-oxidation of p-coumarate for ubiquinone biosynthesis. The enzyme is part of the same clade (V) of acyl-activating enzymes than At4g19010, a p-coumarate CoA ligase known to play a central role in the conversion of p-coumarate into 4-hydroxybenzoate. A 4-cl8 T-DNA knockout displayed a 20% decrease in ubiquinone content compared with wild-type plants, while 4-CL8 overexpression boosted ubiquinone content up to 150% of the control level. Similarly, the isotopic enrichment of ubiquinone's ring was decreased by 28% in the 4-cl8 knockout as compared with wild-type controls when Phe-[Ring-13C6] was fed to the plants. This metabolic blockage could be bypassed via the exogenous supply of 4-hydroxybenzoate, the product of p-coumarate β-oxidation. Arabidopsis 4-CL8 displays a canonical peroxisomal targeting sequence type 1, and confocal microscopy experiments using fused fluorescent reporters demonstrated that this enzyme is imported into peroxisomes. Time course feeding assays using Phe-[Ring-13C6] in a series of Arabidopsis single and double knockouts blocked in the β-oxidative metabolism of p-coumarate (4-cl8; at4g19010; at4g19010 × 4-cl8), flavonol biosynthesis (flavanone-3-hydroxylase), or both (at4g19010 × flavanone-3-hydroxylase) indicated that continuous high light treatments (500 µE m−2 s−1; 24 h) markedly stimulated the de novo biosynthesis of ubiquinone independently of kaempferol catabolism.

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BioMime – A Sirolimus-eluting Coronary Stent System for the Treatment of Patients with De Novo Coronary Lesions – meriT-1 Report

Interventional Cardiology Review ◽

10.15420/icr.2011.6.1.39 ◽

2011 ◽

Vol 6 (1) ◽

pp. 39

Author(s):

Keyword(s):

Stent Thrombosis ◽

Time Course ◽

De Novo ◽

Drug Eluting Stent ◽

Cobalt Chromium ◽

Cardiac Events ◽

End Points ◽

Safety And Efficacy ◽

Binary Restenosis

Background:Since the first reported use of percutaneous transluminal coronary angioplasty, advances in the interventional cardiology arena have been fast paced. Developers and clinicians are adapting from the learning curve awarded by the time-course of drug-eluting stent (DES) evolution. BioMime™ sirolimus-eluting stent (SES) is a step towards biomimicry. The stent is built on a strut of ultra-low thickness (65μm), a cobalt–chromium platform using an intelligent hybrid of closed and open cells allowing for morphology-mediated expansion. It employs a well-known antiproliferative – sirolimus – that elutes from a known biodegradable copolymer formulation within 30 days. The resultant stent demonstrates almost 100% endothelialisation at 30 days in preclinical models.Methods:The meriT-1 was a prospective, single-arm, single-centre trial to evaluate the safety and efficacy of BioMime SES in 30 patients with a single de novo lesion in native coronary arteries. The primary safety and efficacy end-points were major adverse cardiac events (MACE) at 30 days and in-stent late lumen loss at eight months, as measured using quantitative coronary angiographic (QCA) method. Secondary safety and efficacy end-points included MACE at one and two years and angiographic binary restenosis at eight-month angiographic follow-up. Other end-points included the occurrence of stent thrombosis at acute, subacute, late and very late periods and the percentage of diameter stenosis by QCA.Results:No MACE were observed and the median in-stent late luminal loss in 20 (67%) subjects studied by QCA was 0.15mm, with 0% binary restenosis at eight-month follow-up. No stent thrombosis was observed up to one-year follow-up.Conclusions:In comparison to currently available DES, BioMime SES appears to have a considerable scientific basis for prevention of neointimal proliferation, restenosis and associated clinical events.

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Lipid Metabolism Is Dysregulated before, during and after Pregnancy in a Mouse Model of Gestational Diabetes

International Journal of Molecular Sciences ◽

10.3390/ijms22147452 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7452

Author(s):

Samuel Furse ◽

Denise S. Fernandez-Twinn ◽

Davide Chiarugi ◽

Albert Koulman ◽

Susan E. Ozanne

Keyword(s):

Lipid Metabolism ◽

Gestational Diabetes ◽

Glucose Tolerance ◽

Mouse Model ◽

Time Course ◽

De Novo ◽

Lipid Analysis ◽

Temporal Distribution ◽

De Novo Lipogenesis ◽

Analysis Tool

The aim of the current study was to test the hypothesis that maternal lipid metabolism was modulated during normal pregnancy and that these modulations are altered in gestational diabetes mellitus (GDM). We tested this hypothesis using an established mouse model of diet-induced obesity with pregnancy-associated loss of glucose tolerance and a novel lipid analysis tool, Lipid Traffic Analysis, that uses the temporal distribution of lipids to identify differences in the control of lipid metabolism through a time course. Our results suggest that the start of pregnancy is associated with several changes in lipid metabolism, including fewer variables associated with de novo lipogenesis and fewer PUFA-containing lipids in the circulation. Several of the changes in lipid metabolism in healthy pregnancies were less apparent or occurred later in dams who developed GDM. Some changes in maternal lipid metabolism in the obese-GDM group were so late as to only occur as the control dams’ systems began to switch back towards the non-pregnant state. These results demonstrate that lipid metabolism is modulated in healthy pregnancy and the timing of these changes is altered in GDM pregnancies. These findings raise important questions about how lipid metabolism contributes to changes in metabolism during healthy pregnancies. Furthermore, as alterations in the lipidome are present before the loss of glucose tolerance, they could contribute to the development of GDM mechanistically.

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Bayesian approach for predicting responses to therapy from high-dimensional time-course gene expression profiles

BMC Bioinformatics ◽

10.1186/s12859-021-04052-4 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Arika Fukushima ◽

Masahiro Sugimoto ◽

Satoru Hiwa ◽

Tomoyuki Hiroyasu

Keyword(s):

Gene Expression ◽

Time Course ◽

Expression Profiles ◽

Gene Expression Profiles ◽

Response To Therapy ◽

Hcv Infection ◽

Entire Treatment Period ◽

Time Points ◽

Time Course Data ◽

Conventional Methods

Abstract Background Historical and updated information provided by time-course data collected during an entire treatment period proves to be more useful than information provided by single-point data. Accurate predictions made using time-course data on multiple biomarkers that indicate a patient’s response to therapy contribute positively to the decision-making process associated with designing effective treatment programs for various diseases. Therefore, the development of prediction methods incorporating time-course data on multiple markers is necessary. Results We proposed new methods that may be used for prediction and gene selection via time-course gene expression profiles. Our prediction method consolidated multiple probabilities calculated using gene expression profiles collected over a series of time points to predict therapy response. Using two data sets collected from patients with hepatitis C virus (HCV) infection and multiple sclerosis (MS), we performed numerical experiments that predicted response to therapy and evaluated their accuracies. Our methods were more accurate than conventional methods and successfully selected genes, the functions of which were associated with the pathology of HCV infection and MS. Conclusions The proposed method accurately predicted response to therapy using data at multiple time points. It showed higher accuracies at early time points compared to those of conventional methods. Furthermore, this method successfully selected genes that were directly associated with diseases.

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Natural Variation in Plant Pluripotency and Regeneration

Plants ◽

10.3390/plants9101261 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1261

Author(s):

Robin Lardon ◽

Danny Geelen

Keyword(s):

De Novo ◽

Shoot Organogenesis ◽

In Vitro Regeneration ◽

Relative Role ◽

Root Explants ◽

Experimental Systems ◽

Complex Process ◽

Insight Into ◽

Molecular Framework

Plant regeneration is essential for survival upon wounding and is, hence, considered to be a strong natural selective trait. The capacity of plant tissues to regenerate in vitro, however, varies substantially between and within species and depends on the applied incubation conditions. Insight into the genetic factors underlying this variation may help to improve numerous biotechnological applications that exploit in vitro regeneration. Here, we review the state of the art on the molecular framework of de novo shoot organogenesis from root explants in Arabidopsis, which is a complex process controlled by multiple quantitative trait loci of various effect sizes. Two types of factors are distinguished that contribute to natural regenerative variation: master regulators that are conserved in all experimental systems (e.g., WUSCHEL and related homeobox genes) and conditional regulators whose relative role depends on the explant and the incubation settings. We further elaborate on epigenetic variation and protocol variables that likely contribute to differential explant responsivity within species and conclude that in vitro shoot organogenesis occurs at the intersection between (epi) genetics, endogenous hormone levels, and environmental influences.

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Differential expression of TNF-α, IL-6, and IGF-1 by graded mechanical stress in normal rat myocardium

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00436.2001 ◽

2002 ◽

Vol 282 (3) ◽

pp. H926-H934 ◽

Cited By ~ 31

Author(s):

Emiliano A. Palmieri ◽

Giulio Benincasa ◽

Francesca Di Rella ◽

Cosma Casaburi ◽

Maria G. Monti ◽

...

Keyword(s):

Time Course ◽

De Novo ◽

Mechanical Stretch ◽

Progressive Increase ◽

Compensatory Hypertrophy ◽

Current Data ◽

Rat Myocardium ◽

Tnf Α ◽

Normal Rat ◽

Necrosis Factor

An isovolumic normal rat heart Langendorff model was used to examine the effects of moderate (15 mmHg) and severe (35 mmHg) mechanical stretch on the time course (from 0 to 60 min) of myocardial expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and insulin-like growth factor (IGF)-1 and their cognate receptors. After 10 min of moderate stretch, TNF-α was de novo expressed, whereas constitutive IL-6 and IGF-1 levels were slightly upregulated; no further changes occurred up to 60 min. In comparison, severe stretch resulted in a higher and progressive increase in TNF-α, IL-6, and IGF-1 expression up to 20 min. After 20 min, whereas TNF-α expression further increased, IL-6 and IGF-1 levels progressively reduced to values lower than those observed under moderate stretch and in unstretched (5 mmHg) control myocardium (IL-6). Mechanical stretch did not significantly alter the expression of the cognate receptors. Indeed, the TNF-α receptor (p55) tended to be progressively upregulated under severe stretch over time. The current data provide the first demonstration that TNF-α, IL-6, and IGF-1 ligand-receptor systems are differentially expressed within the normal rat myocardium in response to graded mechanical stretch. Such findings may have potential implications with regard to compensatory hypertrophy and failure.

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Inference of gene regulatory networks and compound mode of action from time course gene expression profiles

Bioinformatics ◽

10.1093/bioinformatics/btl003 ◽

2006 ◽

Vol 22 (7) ◽

pp. 815-822 ◽

Cited By ~ 254

Author(s):

M. Bansal ◽

G. D. Gatta ◽

D. di Bernardo

Keyword(s):

Gene Expression ◽

Gene Regulatory Networks ◽

Mode Of Action ◽

Regulatory Networks ◽

Time Course ◽

Expression Profiles ◽

Gene Expression Profiles ◽

Gene Regulatory

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Distinct Biphasic mRNA Changes in Response to Asian Soybean Rust Infection

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-20-8-0887 ◽

2007 ◽

Vol 20 (8) ◽

pp. 887-899 ◽

Cited By ~ 84

Author(s):

Martijn van de Mortel ◽

Justin C. Recknor ◽

Michelle A. Graham ◽

Dan Nettleton ◽

Jaime D. Dittman ◽

...

Keyword(s):

Gene Expression ◽

Time Course ◽

Expression Profiles ◽

Fungal Growth ◽

Initial Response ◽

Soybean Rust ◽

Specific Response ◽

Susceptible Genotype ◽

Rust Infection ◽

Asian Soybean Rust

Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, is now established in all major soybean-producing countries. Currently, there is little information about the molecular basis of ASR–soybean interactions, which will be needed to assist future efforts to develop effective resistance. Toward this end, abundance changes of soybean mRNAs were measured over a 7-day ASR infection time course in mock-inoculated and infected leaves of a soybean accession (PI230970) carrying the Rpp2 resistance gene and a susceptible genotype (Embrapa-48). The expression profiles of differentially expressed genes (ASR-infected compared with the mock-inoculated control) revealed a biphasic response to ASR in each genotype. Within the first 12 h after inoculation (hai), which corresponds to fungal germination and penetration of the epidermal cells, differential gene expression changes were evident in both genotypes. mRNA expression of these genes mostly returned to levels found in mock-inoculated plants by 24 hai. In the susceptible genotype, gene expression remained unaffected by rust infection until 96 hai, a time period when rapid fungal growth began. In contrast, gene expression in the resistant genotype diverged from the mock-inoculated control earlier, at 72 h, demonstrating that Rpp2-mediated defenses were initiated prior to this time. These data suggest that ASR initially induces a non-specific response that is transient or is suppressed when early steps in colonization are completed in both soybean genotypes. The race-specific resistance phenotype of Rpp2 is manifested in massive gene expression changes after the initial response prior to the onset of rapid fungal growth that occurs in the susceptible genotype.

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Glucocorticoid-regulated compartmentalization of cell surface-associated glycoproteins in rat hepatoma cells: evidence for an independent response that requires receptor function and de novo RNA synthesis

Molecular and Cellular Biology ◽

10.1128/mcb.7.4.1508-1517.1987 ◽

1987 ◽

Vol 7 (4) ◽

pp. 1508-1517

Author(s):

O K Haffar ◽

A K Vallerga ◽

S A Marenda ◽

H J Witchel ◽

G L Firestone

Keyword(s):

Cell Surface ◽

Time Course ◽

Rna Synthesis ◽

De Novo ◽

Receptor Occupancy ◽

Receptor Function ◽

Intracellular Fraction ◽

Culture Cells ◽

Viral Glycoproteins ◽

Rat Hepatoma

The role of glucocorticoid hormones in the compartmentalization of cell surface-associated mouse mammary tumor virus (MMTV) glycoproteins was examined in M1.54, a cloned line of MMTV-infected rat hepatoma tissue culture cells. The expression of cellular [2-3H]mannose-labeled and cell surface 125I-labeled MMTV glycoproteins was examined throughout a time course of exposure to dexamethasone, a synthetic glucocorticoid. Posttranslational localization of cell surface MMTV glycoproteins required 6 h of exposure to hormone and occurred approximately 4 h after their initial production in an intracellular fraction. This regulated localization to the cell surface correlated with glucocorticoid receptor occupancy and was inhibited by exposure to RU 38486, a powerful antagonist of glucocorticoid-mediated responses. Cell surface immunoprecipitation demonstrated that actinomycin D, an inhibitor of de novo RNA synthesis, prevented regulated expression of cell surface viral glycoproteins, suggesting that newly synthesized cellular components mediate this process. The localization of cell surface MMTV glycoproteins appeared normal in a transcriptional variant (CR1) that produces basal levels of MMTV RNA and glycoprotein precursors in the presence of dexamethasone. Thus, regulated compartmentalization of viral glycoproteins is not an obligate consequence of a critical precursor concentration. Taken together, our results suggest that posttranslational trafficking of cell surface-destined MMTV glycoproteins resulted from an independent glucocorticoid hormone response that required receptor function and de novo RNA synthesis.

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