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"Ast, Volker"
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Transcriptomic alterations during ageing reflect the shift from cancer to degenerative diseases in the elderly
2018
Disease epidemiology during ageing shows a transition from cancer to degenerative chronic disorders as dominant contributors to mortality in the old. Nevertheless, it has remained unclear to what extent molecular signatures of ageing reflect this phenomenon. Here we report on the identification of a conserved transcriptomic signature of ageing based on gene expression data from four vertebrate species across four tissues. We find that ageing-associated transcriptomic changes follow trajectories similar to the transcriptional alterations observed in degenerative ageing diseases but are in opposite direction to the transcriptomic alterations observed in cancer. We confirm the existence of a similar antagonism on the genomic level, where a majority of shared risk alleles which increase the risk of cancer decrease the risk of chronic degenerative disorders and vice versa. These results reveal a fundamental trade-off between cancer and degenerative ageing diseases that sheds light on the pronounced shift in their epidemiology during ageing.
Ageing is associated with a pronounced shift in mortality from cancer to degenerative diseases. Here, the authors show that in concordance with this shift, conserved transcriptional alterations during ageing across four vertebrates align with degenerative diseases but are opposite to those in cancer.
Journal Article
Sphingosine-1-Phosphate-derived 2-Hexadecenal is a central mediator of ocular neovascularization by inhibiting Sphingosine-1-Phosphate receptor 5
2026
Sphingosine-1-phosphate (S1P) is a crucial sphingolipid mediator in vasculature and neovascular eye diseases by controlling angiogenesis, inflammation and fibrosis. Five S1P receptors (S1PRs) are key therapeutic targets, with several S1PR-targeted drugs already in clinical use or trials. However, the vascular function of its major metabolic product, the reactive lipid aldehyde 2-hexadecenal (2-HD), remains unexplored. Here, we show that loss of the aldehyde dehydrogenase ALDH3B1 impairs 2-HD detoxification and leads to retinal vascular abnormalities in zebrafish, without affecting the trunk vasculature. Mechanistically, multi-omics analyses reveal that 2-HD accumulation disrupts iron homeostasis and induces ferroptosis by directly interacting with S1PR5. This finding is supported by integrative analyses of single-cell RNA sequencing and RNA sequencing from human neovascular retinal samples, identifying S1PR5 as a clinically relevant target. These findings uncover a previously unrecognized role of S1P derived 2-HD in vasculature and retinal vascular homeostasis, suggesting that targeting S1PR5 could offer a therapeutic strategy for diabetic retinopathy.
Sphingolipids mediate inflammation, although the role of lipid aldehyde 2-HD is poorly understood. Here, the authors show ALDH3B1 detoxifies 2-HD to protect retinal vasculature, with 2HD accumulation causing vascular abnormalities.
Journal Article
S100A9 and HMGB1 orchestrate MDSC-mediated immunosuppression in melanoma through TLR4 signaling
by
Wohlfeil, Sebastian A
,
Tavukcuoglu, Ece
,
Utikal, Jochen
in
Basic Tumor Immunology
,
Biomarkers
,
Calgranulin B - metabolism
2024
BackgroundImmunotherapies for malignant melanoma are challenged by the resistance developed in a significant proportion of patients. Myeloid-derived suppressor cells (MDSC), with their ability to inhibit antitumor T-cell responses, are a major contributor to immunosuppression and resistance to immune checkpoint therapies in melanoma. Damage-associated molecular patterns S100A8, S100A9, and HMGB1, acting as toll like receptor 4 (TLR4) and receptor for advanced glycation endproducts (RAGE) ligands, are highly expressed in the tumor microenvironment and drive MDSC activation. However, the role of TLR4 and RAGE signaling in the acquisition of MDSC immunosuppressive properties remains to be better defined. Our study investigates how the signaling via TLR4 and RAGE as well as their ligands S100A9 and HMGB1, shape MDSC-mediated immunosuppression in melanoma.MethodsMDSC were isolated from the peripheral blood of patients with advanced melanoma or generated in vitro from healthy donor-derived monocytes. Monocytes were treated with S100A9 or HMGB1 for 72 hours. The immunosuppressive capacity of treated monocytes was assessed in the inhibition of T-cell proliferation assay in the presence or absence of TLR4 and RAGE inhibitors. Plasma levels of S100A8/9 and HMGB1 were quantified by ELISA. Single-cell RNA sequencing (scRNA-seq) was performed on monocytes from patients with melanoma and healthy donors.ResultsWe showed that exposure to S100A9 and HMGB1 converted healthy donor-derived monocytes into MDSC through TLR4 signaling. Our scRNA-seq data revealed in patient monocytes enriched inflammatory genes, including S100 and those involved in NF-κB and TLR4 signaling, and a reduced major histocompatibility complex II gene expression. Furthermore, elevated plasma S100A8/9 levels correlated with shorter progression-free survival in patients with melanoma.ConclusionsThese findings highlight the critical role of TLR4 and, to a lesser extent, RAGE signaling in the conversion of monocytes into MDSC-like cells, underscore the potential of targeting S100A9 to prevent this conversion, and highlight the prognostic value of S100A8/9 as a plasma biomarker in melanoma.
Journal Article
Results of a European-Wide External Quality Assessment (EQA) Scheme for Serological Detection of Anti-SARS-CoV-2 (CoVimm)—Pitfalls of Routine Application
2022
Background: During the last two years, a variety of assays for the serological detection of antibodies to the new SARS-CoV-2 virus have been launched and used as part of standard care in many laboratories. The pace with which these tests have been introduced into routine care emphasizes the importance of quality measures for analytical methods, particularly with regard to the implications of results for clinical and epidemiologic decisions. Accuracy, reliability and comparability of analytical test results are thus essential, and here external quality assessment (EQA) is the most important quality assurance tool. It allows us to achieve harmonization of test methods as a prerequisite for a high standard of performance for laboratory and analytical techniques and their interpretation. Methods: This EQA scheme consisted of pre-characterized clinical biospecimens dedicated to the analysis of anti-SARS-CoV-2 IgG total antibodies and differentiation into spike protein-specific IgG antibodies against SARS-CoV-2 (anti-S-SARS-CoV-2) and nucleocapsid-specific IgG antibodies against SARS-CoV-2 (anti-N-SARS-CoV-2). Results: A total of 239 laboratories across Europe participated in this scheme, called CoVimm. In detail, 536 results for anti-SARS-CoV-2 IgG, 431 results for anti-S-SARS-CoV-2 IgG, and 200 results for anti-N-SARS-CoV-2 IgG were reported. Based on the pre-defined thresholds, the success rates for the determination of anti-S-SARS-CoV-2 IgG and anti-N-SARS-CoV-2 IgG were 96% and 90%, respectively. Interestingly, only 64% of the participating laboratories successfully passed the EQA scheme for the determination of total anti-SARS-CoV-2 IgG. Conclusions: This EQA revealed serious concerns regarding the reliability and appropriate use of anti-SARS-CoV-2 antibody assays in routine care. In addition to the wide heterogeneity of different assays used by participating laboratories, a lack of standardization and harmonization is also evident. This is of particular importance for reliable and clinically meaningful interpretation of test results.
Journal Article
Humoral SARS-CoV-2 Immune Response in COVID-19 Recovered Vaccinated and Unvaccinated Individuals Related to Post-COVID-Syndrome
by
Neumaier, Michael
,
Hetjens, Michael
,
Ast, Volker
in
anti-SARS-CoV-2 antibodies
,
Antibodies
,
Antibodies, Viral
2023
Background: The duration of anti-SARS-CoV-2-antibody detectability up to 12 months was examined in individuals after either single convalescence or convalescence and vaccination. Moreover, variables that might influence an anti-RBD/S1 antibody decline and the existence of a post-COVID-syndrome (PCS) were addressed. Methods: Forty-nine SARS-CoV-2-qRT-PCR-confirmed participants completed a 12-month examination of anti-SARS-CoV-2-antibody levels and PCS-associated long-term sequelae. Overall, 324 samples were collected. Cell-free DNA (cfDNA) was isolated and quantified from EDTA-plasma. As cfDNA is released into the bloodstream from dying cells, it might provide information on organ damage in the late recovery of COIVD-19. Therefore, we evaluated cfDNA concentrations as a biomarker for a PCS. In the context of antibody dynamics, a random forest-based logistic regression with antibody decline as the target was performed and internally validated. Results: The mean percentage dynamic related to the maximum measured value was 96 (±38)% for anti-RBD/S1 antibodies and 30 (±26)% for anti-N antibodies. Anti-RBD/S1 antibodies decreased in 37%, whereas anti-SARS-CoV-2-anti-N antibodies decreased in 86% of the subjects. Clinical anti-RBD/S1 antibody decline prediction models, including vascular and other diseases, were cross-validated (highest AUC 0.74). Long-term follow-up revealed no significant reduction in PCS prevalence but an increase in cognitive impairment, with no indication for cfDNA as a marker for a PCS. Conclusion: Long-term anti-RBD/S1-antibody positivity was confirmed, and clinical parameters associated with declining titers were presented. A fulminant decrease in anti-SARS-CoV-2-anti-N antibodies was observed (mean change to maximum value 30 (±26)%). Anti-RBD/S1 antibody titers of SARS-CoV-2 recovered subjects boosted with a vaccine exceeded the maximum values measured after single infection by 235 ± 382-fold, with no influence on preexisting PCS. PCS long-term prevalence was 38.6%, with an increase in cognitive impairment compromising the quality of life. Quantified cfDNA measured in the early post-COVID-19 phase might not be an effective marker for PCS identification.
Journal Article
Modelling TERT regulation across 19 different cancer types based on the MIPRIP 2.0 gene regulatory network approach
2019
Background
Reactivation of the telomerase reverse transcriptase gene
TERT
is a central feature for unlimited proliferation of the majority of cancers. However, the underlying regulatory processes are only partly understood.
Results
We assembled regulator binding information from serveral sources to construct a generic human and mouse gene regulatory network. Advancing our “Mixed Integer linear Programming based Regulatory Interaction Predictor” (MIPRIP) approach, we identified the most common and cancer-type specific regulators of
TERT
across 19 different human cancers. The results were validated by using the well-known
TERT
regulation by the ETS1 transcription factor in a subset of melanomas with mutations in the
TERT
promoter.
Our improved MIPRIP2 R-package and the associated generic regulatory networks are freely available at
https://github.com/KoenigLabNM/MIPRIP
.
Conclusion
MIPRIP 2.0 identified common as well as tumor type specific regulators of
TERT
. The software can be easily applied to transcriptome datasets to predict gene regulation for any gene and disease/condition under investigation.
Journal Article
Molecular characterization of cell decay in inflammation and topological assignment of released cfDNA for integrative laboratory and radiological outcome assessment
2026
Integrative biomarkers could aid in the efficient triage of vulnerable patients with systemic infectious diseases. Thus, we investigated cfDNA integrity, cfDNA epigenetics, and radiomics for their potential as prognostic biomarkers for clinical courses in ARDS and systemic involvement.
The cfDNA integrity index was established using automated gel electrophoresis (TapeStation) based on the release of cfDNA induced by apoptosis and necrosis in HEK293 and Jurkat cells (discovery cohort). This method was then used to evaluate cfDNA fragmentation patterns in blood samples from participants with COVID-19 or other acute diseases (validation cohort). In this analysis, various cfDNA size intervals (50-130 bp, 130-270 bp, 270-450 bp, 450-640 bp, 640-800 bp) were considered, and both the classic DNA integrity index (247/50-800 bp) and an adjusted index (450/50-800 bp) were assessed for their clinical potential in respiratory diseases. Infinium Methylation 850K assay was utilized for topological assignment of secondary organ damage via epigenetic analysis of cfDNA via deconvolution. In total, 122 samples, including cell culture and patient samples, were analysed.
Participants with ARDS exhibited higher cfDNA concentrations with fragment sizes above 247 bp (p = 0.016). Increased cfDNA fragment sizes were observed in association with ICU admission (p = 0.009) and mortality (p = 0.017). The predominant origin of cfDNA was hematopoietic cells. An elevated epigenetic hepatocyte signal showed a strong correlation with GGT levels (r = 0.79). Hepatocyte-derived cfDNA anticipated later ALT elevation (p = 0.008). ECMO was correlated with selected radiomics parameters (r = -0.84).
Implementing the cfDNA integrity index on an automated gel electrophoresis demonstrated promising results in predicting clinical outcomes like ARDS occurrence and mortality. Therefore, integrating laboratory and imaging resources could enhance the allocation of optimal care and may identify secondary systemic complications, especially liver involvement, as our results suggest reduced lead-time for detecting liver injury.
Journal Article
Liquid profiling of circulating tumor DNA in colorectal cancer: steps needed to achieve its full clinical value as standard care
by
Neumaier, Michael
,
Duda, Angelika
,
Costina, Victor
in
Accreditation
,
Biomarkers
,
Biomarkers, Tumor - genetics
2022
The analysis of circulating tumor DNA (ctDNA) is at the threshold of implementation into standard care for colorectal cancer (CRC) patients. However, data about the clinical utility of liquid profiling (LP), its acceptance by clinicians, and its integration into clinical workflows in real‐world settings remain limited. Here, LP tests requested as part of routine care since 2016 were retrospectively evaluated. Results show restrained request behavior that improved moderately over time, as well as reliable diagnostic performance comparable to translational studies, with an overall agreement of 91.7%. Extremely low ctDNA levels at < 0.1% in over 20% of cases, a high frequency of concomitant driver mutations (in up to 14% of cases), and ctDNA levels reflecting the clinical course of disease were revealed. However, certain limitations hampering successful translation of ctDNA into clinical practice were uncovered, including the lack of clinically relevant ctDNA thresholds, appropriate time points of LP requests, and integrative evaluation of ctDNA, imaging, and clinical findings. In conclusion, these results highlight the potential clinical value of LP for CRC patient management and demonstrate issues that need to be addressed for successful long‐term implementation in clinical workflows. Liquid profiling (LP) is a promising approach for real‐time assessment of the cumulative tumor mutational profile from a single blood draw. Currently, the workflow is about to be implemented into standard of care for the management of patients with colorectal cancer (CRC), with the aim to better guide CRC diagnostics and optimize therapeutic decisions. Here we report our 5‐year, single medical center clinical experience in LP for CRC patient management.
Journal Article
Publisher Correction: Transcriptomic alterations during ageing reflect the shift from cancer to degenerative diseases in the elderly
2019
The original version of this Article contained an error in the spelling of the author Jule Müller, which was incorrectly given as Julia Müller. Additionally, in Fig. 4a, the blue-red colour scale for fold change in ageing/disease regulation included a blue stripe in place of a red stripe at the right-hand end of the scale. These errors have been corrected in both the PDF and HTML versions of the Article.
Journal Article
Lack of CD45 in FLT3-ITD mice results in a myeloproliferative phenotype, cortical porosity, and ectopic bone formation
2019
The receptor tyrosine kinase FLT3 is expressed in myeloid and lymphoid progenitor cells. Activating mutations in FLT3 occur in 25–30% of acute myeloid leukaemia (AML) patients. Most common are internal tandem duplications of sequence (ITD) leading to constitutive FLT3-ITD kinase activity with an altered signalling quality promoting leukaemic cell transformation. Here, we observed the attenuating role of the receptor-like protein tyrosine phosphatase (RPTP) CD45/Ptprc in FLT3 signalling in vivo. Low level expression of this abundant RPTP correlates with a poor prognosis of FLT3-ITD-positive AML patients. To get a further insight into the regulatory role of Ptprc in FLT3-ITD activity in vivo,
Ptprc
knock-out mice were bred with FLT3-ITD knock-in mice. Inactivation of the
Ptprc
gene in FLT3-ITD mice resulted in a drastically shortened life span and development of severe monocytosis, a block in B-cell development and anaemia. The myeloproliferative phenotype was associated with extramedullary haematopoiesis, splenohepatomegaly and severe alterations of organ structures. The phenotypic alterations were associated with increased transforming signalling of FLT3-ITD, including activation of its downstream target STAT5. These data reveal the capacity of Ptprc for the regulation of FLT3-ITD signalling activity in vivo. In addition, histopathology and computed tomography (CT) revealed an unexpected bone phenotype; the FLT3-ITD
Ptprc
-/-
mice, but none of the controls, showed pronounced alterations in bone morphology and, in part, apparent features of osteoporosis. In the spleen, ectopic bone formation was observed. The observed bone phenotypes suggest a previously unappreciated capacity of FLT3-ITD (and presumably FLT3) to regulate bone development/remodelling, which is under negative control of CD45/Ptprc.
Key points
Low
PTPRC
expression of FLT3-ITD-positive AML patients correlates with poor prognosis
FLT3-ITD/
Ptprc
-/-
mice develop severe monocytosis, a block in B-cell formation and anaemia
FLT3-ITD/
Ptprc
-/-
mice develop myeloproliferative neoplasm with extramedullary haematopoiesis and splenohepatomegaly
Inactivation of
Ptprc
in the presence of FLT3-ITD results in cortical porosity and ectopic bone formation
Ptprc is negatively regulating transforming FLT3-ITD signalling in vivo
Journal Article