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Renata Zuber, Michaela Norum, Yiwen Wang, Kathrin Oehl, Nicole Gehring, Davide Accardi, Slawomir Bartozsewski, Jürgen Berger, Matthias Flötenmeyer, Bernard Moussian
The ABC transporter Snu and the extracellular protein Snsl cooperate in the formation of the lipid-based inward and outward barrier in the skin of Drosophila.
Eur J Cell Biol, Art. No. doi: 10.1016/j.ejcb.2017.12.003 (2018)
PubMed Source   

Lipids in extracellular matrices (ECM) contribute to barrier function and stability of epithelial tissues such as the pulmonary alveoli and the skin. In insects, skin waterproofness depends on the outermost layer of the extracellular cuticle termed envelope that contains cuticulin, an unidentified water-repellent complex molecule composed of proteins, lipids and catecholamines. Based on live-imaging analyses of fruit fly larvae, we find that initially envelope units are assembled within putative vesicles harbouring the ABC transporter Snu and the extracellular protein Snsl. In a second step, the content of these vesicles is distributed to cuticular lipid-transporting nanotubes named pore canals and to the cuticle surface in dependence of Snu function. Consistently, the surface of snu and snsl mutant larvae is depleted from lipids and cuticulin. By consequence, these animals suffer uncontrolled water loss and penetration of xenobiotics. Our data allude to a two-step model of envelope i.e. barrier formation. The proposed mechanism in principle parallels the events occurring during differentiation of the lipid-based ECM by keratinocytes in the vertebrate skin suggesting establishment of analogous mechanisms of skin barrier formation in vertebrates and invertebrates.
@article{Zuber7027,
author={Renata Zuber, Michaela Norum, Yiwen Wang, Kathrin Oehl, Nicole Gehring, Davide Accardi, Slawomir Bartozsewski, Jürgen Berger, Matthias Flötenmeyer, Bernard Moussian},
title={The ABC transporter Snu and the extracellular protein Snsl cooperate in the formation of the lipid-based inward and outward barrier in the skin of Drosophila.},
journal={European journal of cell biology},
volume={},
pages={1--1},
year=2018
}

Matthias Kaiser, Florian Jug, Thomas Julou, Siddharth Deshpande, Thomas Pfohl, Olin Silander, Gene Myers, Erik van Nimwegen
Monitoring single-cell gene regulation under dynamically controllable conditions with integrated micro fl uidics and software
Nat Commun, Art. No. doi: 10.1038/s41467-017-02505-0 (2018)
Source  

@article{Kaiser7024,
author={Matthias Kaiser, Florian Jug, Thomas Julou, Siddharth Deshpande, Thomas Pfohl, Olin Silander, Gene Myers, Erik van Nimwegen},
title={Monitoring single-cell gene regulation under dynamically controllable conditions with integrated micro fl uidics and software},
journal={Nature communications},
volume={},
pages={1--1},
year=2018
}

Catarina Oliveira, Regis P. Lemaitre, Prayag Murawala, Akira Tazaki, David N. Drechsel, Elly M. Tanaka
Pseudotyped baculovirus is an effective gene expression tool for studying molecular function during axolotl limb regeneration.
Dev Biol, 433(2) 262-275 (2018)
PubMed Source   

Axolotls can regenerate complex structures through recruitment and remodeling of cells within mature tissues. Accessing the underlying mechanisms at a molecular resolution is crucial to understand how injury triggers regeneration and how it proceeds. However, gene transformation in adult tissues can be challenging. Here we characterize the use of pseudotyped baculovirus (BV) as an effective gene transfer method both for cells within mature limb tissue and within the blastema. These cells remain competent to participate in regeneration after transduction. We further characterize the effectiveness of BV for gene overexpression studies by overexpressing Shh in the blastema, which yields a high penetrance of classic polydactyly phenotypes. Overall, our work establishes BV as a powerful tool to access gene function in axolotl limb regeneration.
@article{Oliveira6995,
author={Catarina Oliveira, Regis P. Lemaitre, Prayag Murawala, Akira Tazaki, David N. Drechsel, Elly M. Tanaka},
title={Pseudotyped baculovirus is an effective gene expression tool for studying molecular function during axolotl limb regeneration.},
journal={Developmental biology},
volume={433},
issue ={2},
pages={262--275},
year=2018
}

Franziska Decker, David Oriola, Benjamin Dalton, Jan Brugues
Autocatalytic microtubule nucleation determines the size and mass of Xenopus laevis egg extract spindles.
Elife, 7 Art. No. e31149 (2018)
PubMed Source   

Regulation of size and growth is a fundamental problem in biology. A prominent example is the formation of the mitotic spindle, where protein concentration gradients around chromosomes are thought to regulate spindle growth by controlling microtubule nucleation. Previous evidence suggests that microtubules nucleate throughout the spindle structure. However, the mechanisms underlying microtubule nucleation and its spatial regulation are still unclear. Here, we developed an assay based on laser ablation to directly probe microtubule nucleation events in Xenopuslaevis egg extracts. Combining this method with theory and quantitative microscopy, we show that the size of a spindle is controlled by autocatalytic growth of microtubules, driven by microtubule-stimulated microtubule nucleation. The autocatalytic activity of this nucleation system is spatially regulated by the limiting amounts of active microtubule nucleators, which decrease with distance from the chromosomes. This mechanism provides an upper limit to spindle size even when resources are not limiting.
@article{Decker7023,
author={Franziska Decker, David Oriola, Benjamin Dalton, Jan Brugues},
title={Autocatalytic microtubule nucleation determines the size and mass of Xenopus laevis egg extract spindles.},
journal={eLife},
volume={7},
pages={1--1},
year=2018
}

Ioannis Mitroulis, Klara Ruppova, Baomei Wang, Lan-Sun Chen, Michal Grzybek, Tatyana Grinenko, Anne Eugster, Maria Troullinaki, Alessandra Palladini, Ioannis Kourtzelis, Antonios Chatzigeorgiou, Andreas Schlitzer, Marc Beyer, Leo A B Joosten, Berend Isermann, Mathias Lesche, Andreas Petzold, Kai Simons, Ian Henry, Andreas Dahl, Joachim L Schultze, Ben Wielockx, Nicola Zamboni, Peter Mirtschink, Ünal Coskun, George Hajishengallis, Mihai G Netea, Trian Chavakis
Modulation of Myelopoiesis Progenitors Is an Integral Component of Trained Immunity.
Cell, 172(1-2) 147-161 (2018)
PubMed Source   

Trained innate immunity fosters a sustained favorable response of myeloid cells to a secondary challenge, despite their short lifespan in circulation. We thus hypothesized that trained immunity acts via modulation of hematopoietic stem and progenitor cells (HSPCs). Administration of β-glucan (prototypical trained-immunity-inducing agonist) to mice induced expansion of progenitors of the myeloid lineage, which was associated with elevated signaling by innate immune mediators, such as IL-1β and granulocyte-macrophage colony-stimulating factor (GM-CSF), and with adaptations in glucose metabolism and cholesterol biosynthesis. The trained-immunity-related increase in myelopoiesis resulted in a beneficial response to secondary LPS challenge and protection from chemotherapy-induced myelosuppression in mice. Therefore, modulation of myeloid progenitors in the bone marrow is an integral component of trained immunity, which to date, was considered to involve functional changes of mature myeloid cells in the periphery.
@article{Mitroulis7033,
author={Ioannis Mitroulis, Klara Ruppova, Baomei Wang, Lan-Sun Chen, Michal Grzybek, Tatyana Grinenko, Anne Eugster, Maria Troullinaki, Alessandra Palladini, Ioannis Kourtzelis, Antonios Chatzigeorgiou, Andreas Schlitzer, Marc Beyer, Leo A B Joosten, Berend Isermann, Mathias Lesche, Andreas Petzold, Kai Simons, Ian Henry, Andreas Dahl, Joachim L Schultze, Ben Wielockx, Nicola Zamboni, Peter Mirtschink, Ünal Coskun, George Hajishengallis, Mihai G Netea, Trian Chavakis},
title={Modulation of Myelopoiesis Progenitors Is an Integral Component of Trained Immunity.},
journal={Cell},
volume={172},
issue ={1-2},
pages={147--161},
year=2018
}

Samata Chaudhuri, Till Korten, Slobodanka Korten, Gloria Milani, Tobia Lana, Geertruy Te Kronnie, Stefan Diez
Label-Free Detection of Microvesicles and Proteins by the Bundling of Gliding Microtubules.
Nano Lett, 18(1) 117-123 (2018)
PubMed Source   

Development of miniaturized devices for the rapid and sensitive detection of analyte is crucial for various applications across healthcare, pharmaceutical, environmental, and other industries. Here, we report on the detection of unlabeled analyte by using fluorescently labeled, antibody-conjugated microtubules in a kinesin-1 gliding motility assay. The detection principle is based on the formation of fluorescent supramolecular assemblies of microtubule bundles and spools in the presence of multivalent analytes. We demonstrate the rapid, label-free detection of CD45+ microvesicles derived from leukemia cells. Moreover, we employ our platform for the label-free detection of multivalent proteins at subnanomolar concentrations, as well as for profiling the cross-reactivity between commercially available secondary antibodies. As the detection principle is based on the molecular recognition between antigen and antibody, our method can find general application where it identifies any analyte, including clinically relevant microvesicles and proteins.
@article{Chaudhuri7017,
author={Samata Chaudhuri, Till Korten, Slobodanka Korten, Gloria Milani, Tobia Lana, Geertruy Te Kronnie, Stefan Diez},
title={Label-Free Detection of Microvesicles and Proteins by the Bundling of Gliding Microtubules.},
journal={Nano letters},
volume={18},
issue ={1},
pages={117--123},
year=2018
}

Alf Honigmann, André Nadler
The Next Frontier: Quantitative Biochemistry in Living Cells.
Biochemistry, 57(1) 47-55 (2018)
PubMed Source   

Researchers striving to convert biology into an exact science foremost rely on structural biology and biochemical reconstitution approaches to obtain quantitative data. However, cell biological research is moving at an ever-accelerating speed into areas where these approaches lose much of their edge. Intrinsically unstructured proteins and biochemical interaction networks composed of interchangeable, multivalent, and unspecific interactions pose unique challenges to quantitative biology, as do processes that occur in discrete cellular microenvironments. Here we argue that a conceptual change in our way of conducting biochemical experiments is required to take on these new challenges. We propose that reconstitution of cellular processes in vitro should be much more focused on mimicking the cellular environment in vivo, an approach that requires detailed knowledge of the material properties of cellular compartments, essentially requiring a material science of the cell. In a similar vein, we suggest that quantitative biochemical experiments in vitro should be accompanied by corresponding experiments in vivo, as many newly relevant cellular processes are highly context-dependent. In essence, this constitutes a call for chemical biologists to convert their discipline from a proof-of-principle science to an area that could rightfully be called quantitative biochemistry in living cells. In this essay, we discuss novel techniques and experimental strategies with regard to their potential to fulfill such ambitious aims.
@article{Honigmann7007,
author={Alf Honigmann, André Nadler},
title={The Next Frontier: Quantitative Biochemistry in Living Cells.},
journal={Biochemistry},
volume={57},
issue ={1},
pages={47--55},
year=2018
}

Martina Ugrinic, Adrian Zambrano, Simon Berger, Stephen Mann, T-Y Dora Tang, Andrew deMello
Microfluidic formation of proteinosomes.
Chem. Commun. (Camb.), 54(3) 287-290 (2018)
PubMed Source   

Herein we describe a novel microfluidic method for the generation of proteinosome micro-droplets, based on bovine serum albumin and glucose oxidase conjugated to PNIPAAm chains. The size of such water-in-oil droplets is regulated via control of the input reagent flow rate, with generated proteinosome populations exhibiting narrower size distributions than those observed when using standard bulk methodologies. Importantly, proteinosomes transferred from an oil to an aqueous-environment remain intact, become fully hydrated and exhibit an increase in average size. Moreover, functional proteinosomes prepared via microfluidics exhibit lower Km values and higher enzymatic activities than proteinosomes produced by bulk methodologies.
@article{Ugrinic7002,
author={Martina Ugrinic, Adrian Zambrano, Simon Berger, Stephen Mann, T-Y Dora Tang, Andrew deMello},
title={Microfluidic formation of proteinosomes.},
journal={Chemical communications (Cambridge, England)},
volume={54},
issue ={3},
pages={287--290},
year=2018
}

Milan Esner, Felix Meyenhofer, Marc Bickle
Live-Cell High Content Screening in Drug Development.
Methods Mol Biol, 1683 149-164 (2018)
PubMed Source   

In the past decade, automated microscopy has become an important tool for the drug discovery and development process. The establishment of imaging modalities as screening tools depended on technological breakthroughs in the domain of automated microscopy and automated image analysis. These types of assays are often referred to as high content screening or high content analysis (HCS/HCA). The driving force to adopt imaging for drug development is the quantity and quality of cellular information that can be collected and the enhanced physiological relevance of cellular screening compared to biochemical screening. Most imaging in drug development is performed on fixed cells as this allows uncoupling the preparation of the cells from the acquisition of the images. Live-cell imaging is technically challenging, but is very useful for many aspects of the drug development pipeline such as kinetic studies of compound mode of action or to analyze the motion of cellular components. Most vendors of HCS microscopy systems offer the option of environmental chambers and onboard pipetting on their platforms. This reflects the wish and desire of many customers to have the ability to perform live-cell assays on their HCS automated microscopes. This book chapter summarizes the challenges and advantages of live-cell imaging in drug discovery. Examples of applications are presented and the motivation to perform these assays in kinetic mode is discussed.
@article{Esner6982,
author={Milan Esner, Felix Meyenhofer, Marc Bickle},
title={Live-Cell High Content Screening in Drug Development.},
journal={Methods in molecular biology (Clifton, N.J.)},
volume={1683},
pages={149--164},
year=2018
}

Titus Franzmann, Marcus Jahnel, Andrei I. Pozniakovsky, J. Mahamid, Alex S Holehouse, Elisabeth Nüske, Doris Richter, W. Baumeister, Stephan W. Grill, Rohit V Pappu, Anthony A. Hyman, Simon Alberti
Phase separation of a yeast prion protein promotes cellular fitness.
Science, 359(6371) Art. No. eaao5654 (2018)
PubMed Source   

Despite the important role of prion domains in neurodegenerative disease, their physiological function has remained enigmatic. Previous work with yeast prions has defined prion domains as sequences that form self-propagating aggregates. Here, we uncovered an unexpected function of the canonical yeast prion protein Sup35. In stressed conditions, Sup35 formed protective gels via pH-regulated liquid-like phase separation followed by gelation. Phase separation was mediated by the N-terminal prion domain and regulated by the adjacent pH sensor domain. Phase separation promoted yeast cell survival by rescuing the essential Sup35 translation factor from stress-induced damage. Thus, prion-like domains represent conserved environmental stress sensors that facilitate rapid adaptation in unstable environments by modifying protein phase behavior.
@article{Franzmann7020,
author={Titus Franzmann, Marcus Jahnel, Andrei I. Pozniakovsky, J. Mahamid, Alex S Holehouse, Elisabeth Nüske, Doris Richter, W. Baumeister, Stephan W. Grill, Rohit V Pappu, Anthony A. Hyman, Simon Alberti},
title={Phase separation of a yeast prion protein promotes cellular fitness.},
journal={Science (New York, N.Y.)},
volume={359},
issue ={6371},
pages={null--null},
year=2018
}