0000000000372299
AUTHOR
Sven Danckwardt
Dermal CD207-Negative Migratory Dendritic Cells Are Fully Competent to Prime Protective, Skin Homing Cytotoxic T-Lymphocyte Responses
Dendritic cells (DCs) are important inducers and regulators of T-cell responses. They are able to activate and modulate the differentiation of CD4+ and CD8+ T cells. In the skin, there are at least five phenotypically distinct DC subpopulations that can be distinguished by differential expression of the cell surface markers CD207, CD103, and CD11b. Previous studies have suggested that dermal CD11b−CD207+ conventional type 1 DCs are indispensable for the priming of a skin homing cytotoxic T-lymphocyte response. However, conventional type 1 DCs are also the only skin DC subset capable of cross-presenting exogenous antigens on major histocompatibility complex class I. Thus, it remained unclear…
Glucagon-like peptide-1 receptor signalling reduces microvascular thrombosis, nitro-oxidative stress and platelet activation in endotoxaemic mice
Background and purpose Excessive inflammation in sepsis causes microvascular thrombosis and thrombocytopenia associated with organ dysfunction and high mortality. The present studies aimed to investigate whether inhibition of dipeptidyl peptidase-4 (DPP-4) and supplementation with glucagon-like peptide-1 (GLP-1) receptor agonists improved endotoxaemia-associated microvascular thrombosis via immunomodulatory effects. Experimental approach Endotoxaemia was induced in C57BL/6J mice by a single injection of LPS (17.5 mg kg-1 for survival and 10 mg kg-1 for all other studies). For survival studies, treatment was started 6 h after LPS injection. For all other studies, drugs were injected 48 h bef…
Macrophage protease-activated receptor 2 regulates fetal liver erythropoiesis in mice.
AbstractDeficiencies in many coagulation factors and protease-activated receptors (PARs) affect embryonic development. We describe a defect in definitive erythropoiesis in PAR2-deficient mice. Embryonic PAR2 deficiency increases embryonic death associated with variably severe anemia in comparison with PAR2-expressing embryos. PAR2-deficient fetal livers display reduced macrophage densities, erythroblastic island areas, and messenger RNA expression levels of markers for erythropoiesis and macrophages. Coagulation factor synthesis in the liver coincides with expanding fetal liver hematopoiesis during midgestation, and embryonic factor VII (FVII) deficiency impairs liver macrophage development…
p38 MAPK Controls Prothrombin Expression by Regulated RNA 3′ End Processing
Thrombin is a key protease involved in blood coagulation, complement activation, inflammation, angiogenesis, and tumor invasion. Although induced in many (patho-)physiological conditions, the underlying mechanisms controlling prothrombin expression remained enigmatic. We have now discovered that prothrombin expression is regulated by a posttranscriptional regulatory mechanism responding to stress and inflammation. This mechanism is triggered by external stimuli that activate p38 MAPK. In turn, p38 MAPK upmodulates canonical 3' end processing components and phosphorylates the RNA-binding proteins FBP2 and FBP3, which inhibit 3' end processing of mRNAs, such as prothrombin mRNA, that bear a d…
Microbiota-Induced Type I Interferons Instruct a Poised Basal State of Dendritic Cells
Summary Environmental signals shape host physiology and fitness. Microbiota-derived cues are required to program conventional dendritic cells (cDCs) during the steady state so that they can promptly respond and initiate adaptive immune responses when encountering pathogens. However, the molecular underpinnings of microbiota-guided instructive programs are not well understood. Here, we report that the indigenous microbiota controls constitutive production of type I interferons (IFN-I) by plasmacytoid DCs. Using genome-wide analysis of transcriptional and epigenetic regulomes of cDCs from germ-free and IFN-I receptor (IFNAR)-deficient mice, we found that tonic IFNAR signaling instructs a spec…
A novel rationale for targeting FXI: Insights from the hemostatic microRNA targetome for emerging anticoagulant strategies
Therapeutic targeting of blood coagulation is a challenging task as it interferes with the delicate balance of pro- and anticoagulant activities. Anticoagulants are employed in millions of thrombophilic patients worldwide each year. The treatment and prevention of venous thromboembolism has changed drastically. Traditional vitamin K antagonists are being replaced by direct oral anticoagulants (DOACs), which selectively target coagulation factors Xa or IIa. However for a growing population with comorbidities satisfying therapeutic options are still lacking and the quest for novel therapeutics continues. Recently, targeting factors XI or XII have emerged as new therapeutic strategies. As thes…
Emerging Roles of RNA 3′-end Cleavage and Polyadenylation in Pathogenesis, Diagnosis and Therapy of Human Disorders
A crucial feature of gene expression involves RNA processing to produce 3′ ends through a process termed 3′ end cleavage and polyadenylation (CPA). This ensures the nascent RNA molecule can exit the nucleus and be translated to ultimately give rise to a protein which can execute a function. Further, alternative polyadenylation (APA) can produce distinct transcript isoforms, profoundly expanding the complexity of the transcriptome. CPA is carried out by multi-component protein complexes interacting with multiple RNA motifs and is tightly coupled to transcription, other steps of RNA processing, and even epigenetic modifications. CPA and APA contribute to the maintenance of a multitude of dive…
A novel rationale for targeting FXI: Insights from the hemostatic miRNA targetome for emerging anticoagulant strategies
Abstract The treatment and prevention of thrombosis is currently under a period of rapid change with the replacement of traditional anticoagulant vitamin K antagonists, which impair the biosynthesis of a wide range of blood coagulation factors, with direct oral anticoagulants (DOACs), which specifically target factors FXa or FIIa. Nevertheless therapeutic targeting of blood coagulation is an inherently difficult task as it interferes with the delicate balance of pro- and anticoagulant activities. Although anticoagulants are employed in millions of thrombophilic patients worldwide each year, for a growing population with comorbidities who exhibit an increased risk of bleeding with DOAC treat…
Cluster of differentiation 44 promotes osteosarcoma progression in mice lacking the tumor suppressor Merlin.
Merlin is a versatile tumor suppressor protein encoded by the NF2 gene. Several lines of evidence suggest that Merlin exerts its tumor suppressor activity, at least in part, by forming an inhibitory complex with cluster of differentiation 44 (CD44). Consistently, numerous NF2 mutations in cancer patients are predicted to perturb the interaction of Merlin with CD44. We hypothesized that disruption of the Merlin-CD44 complex through loss of Merlin, unleashes putative tumor- or metastasis-promoting functions of CD44. To evaluate the relevance of the Merlin-CD44 interaction in vivo, we compared tumor growth and progression in Cd44-positive and Cd44-negative Nf2-mutant mice. Heterozygous Nf2-mut…
TREND-DB—a transcriptome-wide atlas of the dynamic landscape of alternative polyadenylation
AbstractAlternative polyadenylation (APA) profoundly expands the transcriptome complexity. Perturbations of APA can disrupt biological processes, ultimately resulting in devastating disorders. A major challenge in identifying mechanisms and consequences of APA (and its perturbations) lies in the complexity of RNA 3’end processing, involving poorly conserved RNA motifs and multi-component complexes consisting of far more than 50 proteins. This is further complicated in that RNA 3’end maturation is closely linked to transcription, RNA processing, and even epigenetic (histone/DNA/RNA) modifications. Here we present TREND-DB (http://shiny.imbei.uni-mainz.de:3838/trend-db), a resource cataloging…
PCF11 links alternative polyadenylation to formation and spontaneous regression of neuroblastoma
AbstractDiversification at the transcriptome 3’end is an important and evolutionarily conserved layer of gene regulation associated with differentiation and dedifferentiation processes. However the underlying mechanisms and functional consequences are poorly defined. Here, we identify extensive transcriptome-3’end-alterations in neuroblastoma, a tumour entity with a paucity of recurrent somatic mutations and an unusually high frequency of spontaneous regression. Utilising extensive RNAi-screening we reveal the landscape and drivers of transcriptome-3’end-diversification, discovering PCF11 as critical regulator, directing alternative polyadenylation (APA) of hundreds of transcripts including…
Large-scale identification of functional microRNA targeting reveals cooperative regulation of the hemostatic system.
Essentials MicroRNAs (miRNAs) regulate the molecular networks controlling biological functions such as hemostasis. We utilized novel methods to analyze miRNA-mediated regulation of the hemostatic system. 52 specific miRNA interactions with 11 key hemostatic associated genes were identified. Functionality and drugability of miRNA-19b-3p against antithrombin were demonstrated in vivo. SUMMARY: Background microRNAs (miRNAs) confer robustness to complex molecular networks regulating biological functions. However, despite the involvement of miRNAs in almost all biological processes, and the importance of the hemostatic system for a multitude of actions in and beyond blood coagulation, the role o…
No Evidence for Classic Thrombotic Microangiopathy in COVID-19
Background: Coronavirus disease-2019 (COVID-19) triggers systemic infection with involvement of the respiratory tract. There are some patients developing haemostatic abnormalities during their infection with a considerably increased risk of death. Materials and Methods: Patients (n = 85) with SARS-CoV-2 infection attending the University Medical Center, Mainz, from 3 March to 15 May 2020 were retrospectively included in this study. Data regarding demography, clinical features, treatment and laboratory parameters were analyzed. Twenty patients were excluded for assessment of disseminated intravascular coagulation (DIC) and thrombotic microangiopathy (TMA) due to lack of laboratory data. Resu…