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result(s) for
"Julia C. Engelmann"
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Zygotic Genome Activation Occurs Shortly after Fertilization in Maize
by
Dresselhaus, Thomas
,
Engelmann, Julia C.
,
Sprunck, Stefanie
in
Activation
,
Body Patterning - genetics
,
Cell Cycle - genetics
2017
The formation of a zygote via the fusion of an egg and sperm cell and its subsequent asymmetric division herald the start of the plant’s life cycle. Zygotic genome activation (ZGA) is thought to occur gradually, with the initial steps of zygote and embryo development being primarily maternally controlled, and subsequent steps being governed by the zygotic genome. Here, using maize (Zea mays) as a model plant system, we determined the timing of zygote development and generated RNA-seq transcriptome profiles of gametes, zygotes, and apical and basal daughter cells. ZGA occurs shortly after fertilization and involves ~10% of the genome being activated in a highly dynamic pattern. In particular, genes encoding transcriptional regulators of various families are activated shortly after fertilization. Further analyses suggested that chromatin assembly is strongly modified after fertilization, that the egg cell is primed to activate the translational machinery, and that hormones likely play a minor role in the initial steps of early embryo development in maize. Our findings provide important insights into gamete and zygote activity in plants, and our RNA-seq transcriptome profiles represent a comprehensive, unique RNA-seq data set that can be used by the research community.
Journal Article
FastqPuri: high-performance preprocessing of RNA-seq data
2019
Background
RNA sequencing (RNA-seq) has become the standard means of analyzing gene and transcript expression in high-throughput. While previously sequence alignment was a time demanding step, fast alignment methods and even more so transcript counting methods which avoid mapping and quantify gene and transcript expression by evaluating whether a read is compatible with a transcript, have led to significant speed-ups in data analysis. Now, the most time demanding step in the analysis of RNA-seq data is preprocessing the raw sequence data, such as running quality control and adapter, contamination and quality filtering before transcript or gene quantification. To do so, many researchers chain different tools, but a comprehensive, flexible and fast software that covers all preprocessing steps is currently missing.
Results
We here present
FastqPuri
, a light-weight and highly efficient preprocessing tool for fastq data.
FastqPuri
provides sequence quality reports on the sample and dataset level with new plots which facilitate decision making for subsequent quality filtering. Moreover,
FastqPuri
efficiently removes adapter sequences and sequences from biological contamination from the data. It accepts both single- and paired-end data in uncompressed or compressed fastq files.
FastqPuri
can be run stand-alone and is suitable to be run within pipelines. We benchmarked
FastqPuri
against existing tools and found that
FastqPuri
is superior in terms of speed, memory usage, versatility and comprehensiveness.
Conclusions
FastqPuri
is a new tool which covers all aspects of short read sequence data preprocessing. It was designed for RNA-seq data to meet the needs for fast preprocessing of fastq data to allow transcript and gene counting, but it is suitable to process any short read sequencing data of which high sequence quality is needed, such as for genome assembly or SNV (single nucleotide variant) detection.
FastqPuri
is most flexible in filtering undesired biological sequences by offering two approaches to optimize speed and memory usage dependent on the total size of the potential contaminating sequences.
FastqPuri
is available at
https://github.com/jengelmann/FastqPuri
. It is implemented in C and R and licensed under GPL v3.
Journal Article
Adaptation of methane-oxidizing bacteria to environmental changes: implications for coastal methane dynamics
by
van Bleijswijk, Judith
,
Ramond, Pierre
,
Engelmann, Julia C.
in
Abundance
,
Adaptability
,
Adaptation
2025
Global warming induces alterations in ocean temperature regimes, as well as in precipitation patterns. This leads to shifts in water column properties, which will increasingly impact coastal ecosystems. These changes may have profound implications for microbial communities such as methane-oxidizing bacteria (MOBs), which play a critical role in regulating methane fluxes and ecosystem dynamics. In this study, we investigate the resilience and adaptability of aerobic MOBs in response to changing environmental conditions. Microcosm incubations with waters from the North Sea and the Wadden Sea collected across different seasons and adjusted for methane availability, temperature, and salinity were used to assess how these factors shape MOB community structure and functional capacity. Our results reveal an increase in the relative abundance of MOBs to up to 57 % in experiments with elevated methane concentrations, highlighting the primary role of methane availability in MOB community development. Temperature and salinity variations, on the other hand, exerted lesser effects on MOB composition and relative abundance. A strong effect on MOB community development was furthermore caused by the origin of the inoculum (location and season). Our results thus suggest a functional redundancy in the variable pools of microbial inocula, enabling multiple MOB clades to cope with drastic changes in environmental parameters. The adaptability of MOB communities is key to understanding their role in mitigating methane emissions from coastal regions in a future ocean with potentially elevated methane and temperature and variable salinity levels.
Journal Article
Cooperative STAT/NF-κB signaling regulates lymphoma metabolic reprogramming and aberrant GOT2 expression
2018
Knowledge of stromal factors that have a role in the transcriptional regulation of metabolic pathways aside from c-Myc is fundamental to improvements in lymphoma therapy. Using a
MYC
-inducible human B-cell line, we observed the cooperative activation of STAT3 and NF-κB by IL10 and CpG stimulation. We show that IL10 + CpG-mediated cell proliferation of MYC
low
cells depends on glutaminolysis. By
13
C- and
15
N-tracing of glutamine metabolism and metabolite rescue experiments, we demonstrate that GOT2 provides aspartate and nucleotides to cells with activated or aberrant Jak/STAT and NF-κB signaling. A model of GOT2 transcriptional regulation is proposed, in which the cooperative phosphorylation of STAT3 and direct joint binding of STAT3 and p65/NF-κB to the proximal
GOT2
promoter are important. Furthermore, high aberrant
GOT2
expression is prognostic in diffuse large B-cell lymphoma underscoring the current findings and importance of stromal factors in lymphoma biology.
Metabolic rewiring of cancer cells can be driven by both extrinsic and intrinsic factors. Here the authors show that microenvironmental factors induce metabolic rewiring of B-cell lymphoma through activation of STAT3 and NF-ΚB resulting in upregulation of the aminotransferase GOT2 and glutamine addiction.
Journal Article
Organic matter degradation in the deep, sulfidic waters of the Black Sea: insights into the ecophysiology of novel anaerobic bacteria
by
Damsté, Jaap S. Sinninghe
,
Engelmann, Julia C.
,
Bale, Nicole J.
in
Amino acids
,
Anopheles
,
Bacteria
2024
Background
Recent studies have reported the identity and functions of key anaerobes involved in the degradation of organic matter (OM) in deep (> 1000 m) sulfidic marine habitats. However, due to the lack of available isolates, detailed investigation of their physiology has been precluded. In this study, we cultivated and characterized the ecophysiology of a wide range of novel anaerobes potentially involved in OM degradation in deep (2000 m depth) sulfidic waters of the Black Sea.
Results
We have successfully cultivated a diverse group of novel anaerobes belonging to various phyla, including
Fusobacteriota
(strain S5),
Bacillota
(strains A1
T
and A2),
Spirochaetota
(strains M1
T
, M2, and S2),
Bacteroidota
(strains B1
T
, B2, S6, L6, SYP, and M2P),
Cloacimonadota
(Cloa-SY6),
Planctomycetota
(Plnct-SY6),
Mycoplasmatota
(Izemo-BS),
Chloroflexota
(Chflx-SY6), and
Desulfobacterota
(strains S3
T
and S3-i). These microorganisms were able to grow at an elevated hydrostatic pressure of up to 50 MPa.
Moreover, this study revealed that different anaerobes were specialized in degrading specific types of OM. Strains affiliated with the phyla
Fusobacteriota
,
Bacillota
,
Planctomycetota
, and
Mycoplasmatota
were found to be specialized in the degradation of cellulose, cellobiose, chitin, and DNA, respectively, while strains affiliated with
Spirochaetota
,
Bacteroidota
,
Cloacimonadota
, and
Chloroflexota
preferred to ferment less complex forms of OM. We also identified members of the phylum
Desulfobacterota
as terminal oxidizers, potentially involved in the consumption of hydrogen produced during fermentation. These results were supported by the identification of genes in the (meta)genomes of the cultivated microbial taxa which encode proteins of specific metabolic pathways. Additionally, we analyzed the composition of membrane lipids of selected taxa, which could be critical for their survival in the harsh environment of the deep sulfidic waters and could potentially be used as biosignatures for these strains in the sulfidic waters of the Black Sea.
Conclusions
This is the first report that demonstrates the cultivation and ecophysiology of such a diverse group of microorganisms from any sulfidic marine habitat. Collectively, this study provides a step forward in our understanding of the microbes thriving in the extreme conditions of the deep sulfidic waters of the Black Sea.
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Video Abstract
Journal Article
A Least Angle Regression Model for the Prediction of Canonical and Non-Canonical miRNA-mRNA Interactions
2012
microRNAs (miRNAs) are short non-coding RNAs with regulatory functions in various biological processes including cell differentiation, development and oncogenic transformation. They can bind to mRNA transcripts of protein-coding genes and repress their translation or lead to mRNA degradation. Conversely, the transcription of miRNAs is regulated by proteins including transcription factors, co-factors, and messenger molecules in signaling pathways, yielding a bidirectional regulatory network of gene and miRNA expression. We describe here a least angle regression approach for uncovering the functional interplay of gene and miRNA regulation based on paired gene and miRNA expression profiles. First, we show that gene expression profiles can indeed be reconstructed from the expression profiles of miRNAs predicted to be regulating the specific gene. Second, we propose a two-step model where in the first step, sequence information is used to constrain the possible set of regulating miRNAs and in the second step, this constraint is relaxed to find regulating miRNAs that do not rely on perfect seed binding. Finally, a bidirectional network comprised of miRNAs regulating genes and genes regulating miRNAs is built from our previous regulatory predictions. After applying the method to a human cancer cell line data set, an analysis of the underlying network reveals miRNAs known to be associated with cancer when dysregulated are predictors of genes with functions in apoptosis. Among the predicted and newly identified targets that lack a classical miRNA seed binding site of a specific oncomir, miR-19b-1, we found an over-representation of genes with functions in apoptosis, which is in accordance with the previous finding that this miRNA is the key oncogenic factor in the mir-17-92 cluster. In addition, we found genes involved in DNA recombination and repair that underline its importance in maintaining the integrity of the cell.
Journal Article
Increased expression of c-Jun in nonalcoholic fatty liver disease
by
Hartmann, Arndt
,
Dorn, Christoph
,
Engelmann, Julia C
in
631/208/199
,
692/699/1503/1607/2750
,
692/699/1503/1607/2751
2014
Overnutrition is the major cause of nonalcoholic fatty liver disease (NAFLD) and its advanced form nonalcoholic steatohepatitis (NASH). We aimed to develop and characterize a murine model, which resembles both the pathology and nutritional situation, of NASH patients in Western societies. Mice were fed with a NASH-inducing diet (ND) containing sucrose, cholesterol and fats rich in saturated fatty acids in a composition, which mimics Western food. After 12 weeks, ND-fed mice revealed obesity and impaired glucose tolerance. In the liver, ND-feeding led to marked steatosis, hepatocellular damage, inflammation and beginning fibrosis. Transcriptome-wide gene expression analysis and search for over-represented transcription factor target sites among the differentially expressed genes identified activator protein-1 (AP-1) as the most likely factor to cause the transcriptional changes in ND livers. Combining differentially expressed gene and protein–protein interaction network analysis identified c-Jun as hub in the largest connected deregulated sub-network in ND livers. Accordingly, ND livers revealed c-Jun-phosphorylation and nuclear translocation. Moreover, hepatic c-Jun expression was enhanced in ND-fed mice. Combined tissue microarray technology and immunohistochemical analysis confirmed enhanced hepatic c-Jun levels in NAFLD patients, which correlated with inflammation, and notably, with the degree of hepatic steatosis. In summary, our new mouse model shows important pathological changes also found in human NASH and indicates c-Jun/AP-1 activation as critical regulator of hepatic alterations. Abundance of c-Jun in NAFLD likely facilitates development and progression of NASH.
Journal Article
Early Senescence and Cell Death in Arabidopsis saul1 Mutants Involves the PAD4-Dependent Salicylic Acid Pathway
by
Philippar, Katrin
,
Subert, Christa
,
Soll, Jürgen
in
Arabidopsis - cytology
,
Arabidopsis - drug effects
,
Arabidopsis - genetics
2012
Age-dependent leaf senescence and cell death in Arabidopsis (Arabidopsis thaliana) requires activation of the transcription factor ORESARA1 (ORE1) and is not initiated prior to a leaf age of 28 d. Here, we investigate the conditional execution of events that regulate early senescence and cell death in senescence-associated ubiquitin ligase1 (saul1) mutants, deficient in the PLANT U-BOX-ARMADILLO E3 ubiquitin ligase SAUL1. In saul1 mutants challenged with low light, the switch of age-dependent cell death was turned on prematurely, as indicated by the accumulation of ORE1 transcripts, induction of the senescence marker gene SENESCENCE-ASSOCIATED GENE12, and cell death. However, ORE1 accumulation by itself was not sufficient to cause saul1 phenotypes, as demonstrated by double mutant analysis. Exposure of saul1 mutants to low light for only 24 h did not result in visible symptoms of senescence; however, the senescence-promoting transcription factor genes WRKY53, WRKY6, and NAC-LIKE ACTIVATED BY AP3/PI were up-regulated, indicating that senescence in saul1 seedlings was already initiated. To resolve the time course of gene expression, microarray experiments were performed at narrow intervals. Differential expression of the genes involved in salicylic acid and defense mechanisms were the earliest events detected, suggesting a central role for salicylic acid in saul1 senescence and cell death. The salicylic acid content increased in low-light-treated saul1 mutants, and application of exogenous salicylic acid was indeed sufficient to trigger saul1 senescence in permissive light conditions. Double mutant analyses showed that PHYTOALEXIN DEFICIENT4 (PAD4) but not NONEXPRESSER OF PR GENES1 (NPR1) is essential for saul1 phenotypes. Our results indicate that saul1 senescence depends on the PAD4-dependent salicylic acid pathway but does not require NPR1 signaling.
Journal Article
High CD206 levels in Hodgkin lymphoma‐educated macrophages are linked to matrix‐remodeling and lymphoma dissemination
by
Specht, Rieke
,
Engelmann, Julia C.
,
Bonin, Frederike
in
Animals
,
Antigens
,
Antigens, CD - metabolism
2020
Macrophages (Mφ) are abundantly present in the tumor microenvironment and may predict outcome in solid tumors and defined lymphoma subtypes. Mφ heterogeneity, the mechanisms of their recruitment, and their differentiation into lymphoma‐promoting, alternatively activated M2‐like phenotypes are still not fully understood. Therefore, further functional studies are required to understand biological mechanisms associated with human tumor‐associated Mφ (TAM). Here, we show that the global mRNA expression and protein abundance of human Mφ differentiated in Hodgkin lymphoma (HL)‐conditioned medium (CM) differ from those of Mφ educated by conditioned media from diffuse large B‐cell lymphoma (DLBCL) cells or, classically, by macrophage colony‐stimulating factor (M‐CSF). Conditioned media from HL cells support TAM differentiation through upregulation of surface antigens such as CD40, CD163, CD206, and PD‐L1. In particular, RNA and cell surface protein expression of mannose receptor 1 (MRC1)/CD206 significantly exceed the levels induced by classical M‐CSF stimulation in M2‐like Mφ; this is regulated by interleukin 13 to a large extent. Functionally, high CD206 enhances mannose‐dependent endocytosis and uptake of type I collagen. Together with high matrix metalloprotease9 secretion, HL‐TAMs appear to be active modulators of the tumor matrix. Preclinical in ovo models show that co‐cultures of HL cells with monocytes or Mφ support dissemination of lymphoma cells via lymphatic vessels, while tumor size and vessel destruction are decreased in comparison with lymphoma‐only tumors. Immunohistology of human HL tissues reveals a fraction of cases feature large numbers of CD206‐positive cells, with high MRC1 expression being characteristic of HL‐stage IV. In summary, the lymphoma‐TAM interaction contributes to matrix‐remodeling and lymphoma cell dissemination.
The study highlights the ability of Hodgkin lymphoma cells to attract and to differentiate monocytes into M2‐like Mφ and the role of IL13 in regulating CD206 but also that CD206 contributes to the remodeling of the tumor microenvironment via take up glycoconjugates as well as type‐I collagen and immunosuppression by PD‐L1 upregulation.
Journal Article
Identification of ADGRE5 as discriminating MYC target between Burkitt lymphoma and diffuse large B-cell lymphoma
by
Tomaszewski, Nancy
,
Kleo, Karsten
,
Engelmann, Julia C.
in
ADGRE5
,
Antigens, CD - genetics
,
B-cell lymphoma
2019
Background
MYC is a heterogeneously expressed transcription factor that plays a multifunctional role in many biological processes such as cell proliferation and differentiation. It is also associated with many types of cancer including the malignant lymphomas. There are two types of aggressive B-cell lymphoma, namely Burkitt lymphoma (BL) and a subgroup of diffuse large cell lymphoma (DLBCL), which both carry
MYC
translocations and overexpress MYC but both differ significantly in their clinical outcome. In DLBCL,
MYC
translocations are associated with an aggressive behavior and poor outcome, whereas MYC-positive BL show a superior outcome.
Methods
To shed light on this phenomenon, we investigated the different modes of actions of MYC in aggressive B-cell lymphoma cell lines subdivided into three groups: (i) MYC-positive BL, (ii) DLBCL with MYC translocation (DLBCLpos) and (iii) DLBCL without MYC translocation (DLBCLneg) for control. In order to identify genome-wide MYC-DNA binding sites a chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-Seq) was performed. In addition, ChIP-Seq for H3K4me3 was used for determination of genomic regions accessible for transcriptional activity. These data were supplemented with gene expression data derived from RNA-Seq.
Results
Bioinformatics integration of all data sets revealed different MYC-binding patterns and transcriptional profiles in MYC-positive BL and DLBCL cell lines indicating different functional roles of MYC for gene regulation in aggressive B-cell lymphomas. Based on this multi-omics analysis we identified
ADGRE5
(alias
CD97
) - a member of the EGF-TM7 subfamily of adhesion G protein-coupled receptors - as a MYC target gene, which is specifically expressed in BL but not in DLBCL regardless of
MYC
translocation.
Conclusion
Our study describes a diverse genome-wide MYC-DNA binding pattern in BL and DLBCL cell lines with and without MYC translocations. Furthermore, we identified ADREG5 as a MYC target gene able to discriminate between BL and DLBCL irrespectively of the presence of
MYC
breaks in DLBCL. Since ADGRE5 plays an important role in tumor cell formation, metastasis and invasion, it might also be instrumental to better understand the different pathobiology of BL and DLBCL and help to explain discrepant clinical characteristics of BL and DLBCL.
Journal Article