Refine
Has Fulltext
- yes (5)
Is part of the Bibliography
- yes (5)
Document Type
- Journal article (4)
- Doctoral Thesis (1)
Language
- English (5)
Keywords
- Entzündung (1)
- Glykomodifizierung (1)
- Glykosylierung (1)
- Inhibitor (1)
- Interleukin (1)
- Interleukin-4 Antagonist (1)
- MGL (1)
- Modifizierung (1)
- Proteinmodifizierung (1)
- Rezeptorblocker (1)
- TH2 Immunantwort (1)
- air-liquid interface (1)
- artificial membrane-permeability (1)
- asthmatic bronchial epithelium (1)
- cytotoxicity (1)
- embryonic stem cells (1)
- epithelial cell culture (1)
- extracellular vesicle (1)
- flippase (1)
- in vitro and in vivo thrombus formation (1)
- in vitro models (1)
- incidence (1)
- lipid asymmetry (1)
- mental disorders (1)
- mental health (1)
- mental illness (1)
- on-a-chip (1)
- permeability (1)
- phagocytosis (1)
- phosphatidylethanolamine (1)
- phosphatidylserine (1)
- platelet activation (1)
- platelet aggregation (1)
- platelets (1)
- prevalence (1)
- pulmonary drug-delivery (1)
- reconstructed human epidermis (1)
- respiratory syncytial virus (1)
- self-employed (1)
- small business (1)
- systematic review (1)
- transport studies (1)
- vesicle-based barrier (1)
Institute
- Rudolf-Virchow-Zentrum (2)
- Graduate School of Life Sciences (1)
- Institut für Experimentelle Biomedizin (1)
- Institut für Klinische Epidemiologie und Biometrie (1)
- Julius-von-Sachs-Institut für Biowissenschaften (1)
- Klinik und Poliklinik für Psychiatrie, Psychosomatik und Psychotherapie (1)
- Lehrstuhl für Tissue Engineering und Regenerative Medizin (1)
- Theodor-Boveri-Institut für Biowissenschaften (1)
Sonstige beteiligte Institutionen
Occurrence of mental illness and mental health risks among the self-employed: a systematic review
(2021)
We aimed to systematically identify and evaluate all studies of good quality that compared the occurrence of mental disorders in the self-employed versus employees. Adhering to the Cochrane guidelines, we conducted a systematic review and searched three major medical databases (MEDLINE, Web of Science, Embase), complemented by hand search. We included 26 (three longitudinal and 23 cross-sectional) population-based studies of good quality (using a validated quality assessment tool), with data from 3,128,877 participants in total. The longest of these studies, a Swedish national register evaluation with 25 years follow-up, showed a higher incidence of mental illness among the self-employed compared to white-collar workers, but a lower incidence compared to blue-collar workers. In the second longitudinal study from Sweden the self-employed had a lower incidence of mental illness compared to both blue- and white-collar workers over 15 years, whereas the third longitudinal study (South Korea) did not find a difference regarding the incidence of depressive symptoms over 6 years. Results from the cross-sectional studies showed associations between self-employment and poor general mental health and stress, but were inconsistent regarding other mental outcomes. Most studies from South Korea found a higher prevalence of mental disorders among the self-employed compared to employees, whereas the results of cross-sectional studies from outside Asia were less consistent. In conclusion, we found evidence from population-based studies for a link between self-employment and increased risk of mental illness. Further longitudinal studies are needed examining the potential risk for the development of mental disorders in specific subtypes of the self-employed.
Monoglyceride lipase (MGL) hydrolyzes monoacylglycerols (MG) to glycerol and one fatty acid. Among the various MG species, MGL also degrades 2-arachidonoylglycerol, the most abundant endocannabinoid and potent activator of the cannabinoid receptors 1 and 2. We investigated the consequences of MGL deficiency on platelet function using systemic (Mgl\(^{−/−}\)) and platelet-specific Mgl-deficient (platMgl\(^{−/−}\)) mice. Despite comparable platelet morphology, loss of MGL was associated with decreased platelet aggregation and reduced response to collagen activation. This was reflected by reduced thrombus formation in vitro, accompanied by a longer bleeding time and a higher blood volume loss. Occlusion time after FeCl\(_3\)-induced injury was markedly reduced in Mgl\(^{−/−}\) mice, which is consistent with contraction of large aggregates and fewer small aggregates in vitro. The absence of any functional changes in platelets from platMgl\(^{−/−}\) mice is in accordance with lipid degradation products or other molecules in the circulation, rather than platelet-specific effects, being responsible for the observed alterations in Mgl\(^{−/−}\) mice. We conclude that genetic deletion of MGL is associated with altered thrombogenesis.
Design of novel IL-4 antagonists employing site-specific chemical and biosynthetic glycosylation
(2021)
The cytokines interleukin 4 (IL-4) and IL-13 are important mediators in the humoral immune response and play a crucial role in the pathogenesis of chronic inflammatory diseases, such as asthma, allergies, and atopic dermatitis. Hence, IL-4 and IL-13 are key targets for treatment of such atopic diseases.
For cell signalling IL-4 can use two transmembrane receptor assemblies, the type I receptor consisting of receptors IL-4R and γc, and type II receptor consisting of receptors IL-4R and IL-13R1. The type II receptor is also the functional receptor of IL-13, receptor sharing being the molecular basis for the partially overlapping effects of IL-4 and IL-13. Since both cytokines require the IL-4R receptor for signal transduction, this allows the dual inhibition of both IL-4 and IL-13 by specifically blocking the receptor IL-4R.
This study describes the design and synthesis of novel antagonistic variants of human IL-4. Chemical modification was used to target positions localized in IL-4 binding sites for γc and IL-13R1 but outside of the binding epitope for IL-4R. In contrast to existing studies, which used synthetic chemical compounds like polyethylene glycol for modification of IL-4, we employed glycan molecules as a natural alternative. Since glycosylation can improve important pharmacological parameters of protein therapeutics, such as immunogenicity and serum half-life, the introduced glycan molecules thus would not only confer a steric hindrance based inhibitory effect but simultaneously might improve the pharmacokinetic profile of the IL-4 antagonist.
For chemical conjugation of glycan molecules, IL-4 variants containing additional cysteine residues were produced employing prokaryotic, as well as eukaryotic expression systems. The thiol-groups of the engineered cysteines thereby allow highly specific modification. Different strategies were developed enabling site-directed coupling of amine- or thiol- functionalized monosaccharides to introduced cysteine residues in IL-4. A linker-based coupling procedure and an approach requiring phenylselenyl bromide activation of IL-4 thiol-groups were hampered by several drawbacks, limiting their feasibility. Surprisingly, a third strategy, which involved refolding of IL-4 cysteine variants in the presence of thiol- glycans, readily allowed synthesis of IL-4 glycoconjugates in form of mixed disulphides in milligram amount. This approach, therefore, has the potential for large-scale synthesis of IL-4 antagonists with highly defined glycosylation. Obtaining a homogenous glycoconjugate with exactly defined glycan pattern would allow using the attached glycan structures for fine-tuning of pharmacokinetic properties of the IL-4 antagonist, such as absorption and metabolic stability.
The IL-4 glycoconjugates generated in this work proved to be highly effective antagonists inhibiting IL-4 and/or IL-13 dependent responses in cell-based experiments and in in vitro binding studies. Glycoengineered IL-4 antagonists thus present valuable alternatives to IL-4 inhibitors used for treatment of atopic diseases such as the neutralizing anti-IL-4R antibody Dupilumab.
Models of the outer epithelia of the human body namely the skin, the intestine and the lung have found valid applications in both research and industrial settings as attractive alternatives to animal testing. A variety of approaches to model these barriers are currently employed in such fields, ranging from the utilization of ex vivo tissue to reconstructed in vitro models, and further to chip-based technologies, synthetic membrane systems and, of increasing current interest, in silico modeling approaches. An international group of experts in the field of epithelial barriers was convened from academia, industry and regulatory bodies to present both the current state of the art of non-animal models of the skin, intestinal and pulmonary barriers in their various fields of application, and to discuss research-based, industry-driven and regulatory-relevant future directions for both the development of new models and the refinement of existing test methods. Issues of model relevance and preference, validation and standardization, acceptance, and the need for simplicity versus complexity were focal themes of the discussions. The outcomes of workshop presentations and discussions, in relation to both current status and future directions in the utilization and development of epithelial barrier models, are presented by the attending experts in the current report.
The lipids phosphatidylserine (PtdSer) and phosphatidylethanolamine (PtdEth) are normally asymmetrically localized to the cytosolic face of membrane bilayers, but can both be externalized during diverse biological processes, including cell division, cell fusion, and cell death. Externalized lipids in the plasma membrane are recognized by lipid-binding proteins to regulate the clearance of cell corpses and other cell debris. However, it is unclear whether PtdSer and PtdEth contribute in similar or distinct ways to these processes. We discovered that disruption of the lipid flippases that maintain PtdSer or PtdEth asymmetry in the plasma membrane have opposite effects on phagocytosis in Caenorhabditis elegans embryos. Constitutive PtdSer externalization caused by disruption of the major PtdSer flippase TAT-1 led to increased phagocytosis of cell debris, sometimes leading to two cells engulfing the same debris. In contrast, PtdEth externalization caused by depletion of the major PtdEth flippase TAT-5 or its activator PAD-1 disrupted phagocytosis. These data suggest that PtdSer and PtdEth externalization have opposite effects on phagocytosis. Furthermore, externalizing PtdEth is associated with increased extracellular vesicle release, and we present evidence that the extent of extracellular vesicle accumulation correlates with the extent of phagocytic defects. Thus, a general loss of lipid asymmetry can have opposing impacts through different lipid subtypes simultaneously exerting disparate effects.