17 research outputs found
ANGI-12EFFICACY OF THE PENTRA®BODY DLX1008, A MONOVALENT ANTIBODY FRAGMENT WITH LOW PICOMOLAR AFFINITY TO VEGF-A, IN HUMAN GLIOMA MODELS IN VITRO AND IN VIVO
Acute mental stress drives vascular inflammation and promotes plaque destabilization in mouse atherosclerosis
Publisher Copyright: © 2021 The Author(s). Published by Oxford University Press on behalf of the European Society of Cardiology.Aims: Mental stress substantially contributes to the initiation and progression of human disease, including cardiovascular conditions. We aim to investigate the underlying mechanisms of these contributions since they remain largely unclear. Methods and results: Here, we show in humans and mice that leucocytes deplete rapidly from the blood after a single episode of acute mental stress. Using cell-tracking experiments in animal models of acute mental stress, we found that stress exposure leads to prompt uptake of inflammatory leucocytes from the blood to distinct tissues including heart, lung, skin, and, if present, atherosclerotic plaques. Mechanistically, we found that acute stress enhances leucocyte influx into mouse atherosclerotic plaques by modulating endothelial cells. Specifically, acute stress increases adhesion molecule expression and chemokine release through locally derived norepinephrine. Either chemical or surgical disruption of norepinephrine signalling diminished stress-induced leucocyte migration into mouse atherosclerotic plaques. Conclusion: Our data show that acute mental stress rapidly amplifies inflammatory leucocyte expansion inside mouse atherosclerotic lesions and promotes plaque vulnerability.publishersversionPeer reviewe
Loyalität, Overperforming und aufgezwungene Expertise: LSBTQ* – Identitäten und Arbeitsalltag in der Polizei
Molitor V, Zimenkova T. Loyalität, Overperforming und aufgezwungene Expertise: LSBTQ* – Identitäten und Arbeitsalltag in der Polizei. In: Seeliger M, Gruhlich J, eds. Intersektionalität, Arbeit und Organisation. Arbeitsgesellschaft im Wandel . Weinheim: Beltz Juventa; 2019: 210
E. coli HMS174(DE3) is a sustainable alternative to BL21(DE3)
Abstract Background Escherichia coli is one of the most widely used hosts for recombinant protein production in academia and industry. Strain BL21(DE3) is frequently employed due to its advantageous feature of lacking proteases which avoids degradation of target protein. Usually it is used in combination with the T7-pET system where induction is performed by one point addition of IPTG. We recently published a few studies regarding lactose induction in BL21(DE3) strains. BL21(DE3) can only take up the glucose-part of the disaccharide when fed with lactose. However, initially additional glucose has to be supplied as otherwise the ATP-related lactose uptake barely happens. Yet, as lactose is an inexpensive compound compared to glucose and IPTG, a new induction strategy by a lactose-only feed during induction seems attractive. Thus, we investigated this idea in the galactose metabolizing strain HMS174(DE3). Results We show that strain HMS174(DE3) can be cultivated on lactose as sole carbon source during induction. We demonstrate that strain HMS174(DE3) exhibits higher product and biomass yields compared to BL21(DE3) when cultivated in a lactose fed-batch. More importantly, HMS174(DE3) cultivated on lactose even expresses more product than BL21(DE3) in a standard IPTG induced glucose fed-batch at the same growth rate. Finally, we demonstrate that productivity in HMS174(DE3) lactose-fed batch cultivations can easily be influenced by the specific lactose uptake rate (qs,lac). This is shown for two model proteins, one expressed in soluble form and one as inclusion body. Conclusions As strain HMS174(DE3) expresses even slightly higher amounts of target protein in a lactose fed-batch than BL21(DE3) in a standard cultivation, it seems a striking alternative for recombinant protein production. Especially for large scale production of industrial enzymes cheap substrates are essential. Besides cost factors, the strategy allows straight forward adjustment of specific product titers by variation of the lactose feed rate
Selective Dehydrocoupling of Phosphines by Lithium Chloride Carbenoids
The
development of a simple, transition-metal-free approach for
the formation of phosphorus–phosphorus bonds through dehydrocoupling
of phosphines is presented. The reaction is mediated by electronically
stabilized lithium chloride carbenoids and affords a variety of different
diphosphines under mild reaction conditions. The developed protocol
is simple and highly efficient and allows the isolation of novel functionalized
diphosphines in high yields
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The Influence of Negative Pressure and of the Harvesting Site on the Characteristics of Human Adipose Tissue-Derived Stromal Cells from Lipoaspirates.
BACKGROUND: Adipose tissue-derived stromal cells (ADSCs) have great potential for cell-based therapies, including tissue engineering. However, various factors can influence the characteristics of isolated ADSCs. METHODS: We studied the influence of the harvesting site, i.e., inner thigh (n = 3), outer thigh (n = 3), outer thigh (n = 3), outer thigh (. RESULTS: We revealed higher initial cell yields from the outer thigh region than from the abdomen region. Negative pressure did not influence the cell yields from the outer thigh region, whereas the yields from the abdomen region were higher under high negative pressure than under low negative pressure. In the subsequent passage, in general, no significant relationship was identified between the different negative pressure and ADSC characteristics. No significant difference was observed in the characteristics of thigh ADSCs and abdomen ADSCs. Only on day 1, the diameter was significantly bigger in outer thigh ADSCs than in abdomen ADSCs. Moreover, we noted a tendency of thigh ADSCs (i.e., inner thigh+outer thigh) to reach a higher cell number on day 7. Discussion. The harvesting site and negative pressure can potentially influence initial cell yields from lipoaspirates. However, for subsequent in vitro culturing and for use in tissue engineering, it seems that the harvesting site and the level of negative pressure do not have a crucial or limiting effect on basic ADSC characteristics.in vitro culturing and for use in tissue engineering, it seems that the harvesting site and the level of negative pressure do not have a crucial or limiting effect on basic ADSC characteristics
Valorisation of cheese whey as substrate and inducer for recombinant protein production in E. coli HMS174(DE3)
Every year worldwide around 190 million tons of cheese whey are generated resulting in a huge environmental burden. We recently published a study where we showed that E. coli strain HMS174(DE3) can be cultivated using only lactose as C-source and inducer. Motivated by the results we investigated using a concentrated whey feed instead of the lactose feed. Spray drying whey and dissolving the powder allowed preparation of a 40-fold concentrated whey containing 91% lactose and 81% protein of the original whey. Cultivations using the concentrated whey feed instead of a defined lactose feed revealed 39% higher growth rates, 24% higher biomass yields and even higher specific product titers for the model enzymes, flavanone 3-hydroxylase and chalcone 3- hydroxylase. Our strategy simultaneously provides a cheap substrate for large-scale production of technical enzymes and an excellent opportunity for cheese whey valorization, reducing the biological burden resulting from whey wastewaters.Fonds zur Förderung der Wissenschaftlichen Forschung
Molecular and Enzymatic Characterization of Flavonoid 3′-Hydroxylase of Malus × domestica
Malus × domestica (apple) accumulates particularly high amounts of dihydrochalcones in various tissues, with phloridzin (phloretin 2′-O-glucoside) being prevalent, although small amounts of 3-hydroxyphloretin and 3-hydroxyphloridzin are also constitutively present. The latter was shown to correlate with increased disease resistance of transgenic M. × domestica plants. Two types of enzymes could be involved in 3-hydroxylation of dihydrochalcones: polyphenol oxidases or the flavonoid 3′-hydroxylase (F3′H), which catalyzes B-ring hydroxylation of flavonoids. We isolated two F3′H cDNA clones from apple leaves and tested recombinant Malus F3′Hs for their substrate specificity. From the two isolated cDNA clones, only F3′HII encoded a functionally active enzyme. In the F3′HI sequence, we identified two putatively relevant amino acids that were exchanged in comparison to that of a previously published F3′HI. Site directed mutagenesis, which exchanged an isoleucine into methionine in position 211 restored the functional activity, which is probably because it is located in an area involved in interaction with the substrate. In contrast to high activity with various flavonoid substrates, the recombinant enzymes did not accept phloretin under assay conditions, making an involvement in the dihydrochalcone biosynthesis unlikely
An archaeal lid-containing feruloyl esterase degrades polyethylene terephthalate
Abstract Polyethylene terephthalate (PET) is a commodity polymer known to globally contaminate marine and terrestrial environments. Today, around 80 bacterial and fungal PET-active enzymes (PETases) are known, originating from four bacterial and two fungal phyla. In contrast, no archaeal enzyme had been identified to degrade PET. Here we report on the structural and biochemical characterization of PET46 (RLI42440.1), an archaeal promiscuous feruloyl esterase exhibiting degradation activity on semi-crystalline PET powder comparable to IsPETase and LCC (wildtypes), and higher activity on bis-, and mono-(2-hydroxyethyl) terephthalate (BHET and MHET). The enzyme, found by a sequence-based metagenome search, is derived from a non-cultivated, deep-sea Candidatus Bathyarchaeota archaeon. Biochemical characterization demonstrated that PET46 is a promiscuous, heat-adapted hydrolase. Its crystal structure was solved at a resolution of 1.71 Å. It shares the core alpha/beta-hydrolase fold with bacterial PETases, but contains a unique lid common in feruloyl esterases, which is involved in substrate binding. Thus, our study widens the currently known diversity of PET-hydrolyzing enzymes, by demonstrating PET depolymerization by a plant cell wall-degrading esterase