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Zimmermann, D.

Publications and source records attributed to Zimmermann, D..

5 recordsLinked to original sources

Inflammatory burning pain depends on a specific line of nociceptors

The development and persistence of burning pain and heat hyperalgesia following tissue injury and the subsequent inflammatory response, depend on the nuclear enzyme mitogen- and stress-activated kinase 1 (MSK1) expressed in a specific subset of transient receptor potential subfamily V member 1 (TRPV1)-expressing primary sensory neurons termed nociceptors, which are specialised for detecting harmful stimuli. Inflammation up-regulates and activates MSK1, and MSK1 governs TRPV1 expression in the MSK1 and TRPV1 co-expressing mouse and human nociceptors. Importantly, inhibition of inflammatory MSK1-mediated TRPV1 upregulation protects from heat hypersensitivity without affecting other relevant TRPV1 functions, such as the sensation of acute painful heat stimuli or the maintenance of the body core temperature. The newly discovered importance of the interaction between MSK1 and TRPV1 in a specific line of nociceptors provides mechanistic understanding of inflammatory pain and heat hyperalgesia pathogenesis.

neuroscience↗

Biophysical Essentials - A Full Stack Open-Source Software Framework for Conserved and Advanced Analysis of Patch-Clamp Recordings

Patch-Clamp recordings allow for in depth electrophysiological characterization of single cells, their general biophysical properties as well as characteristics of voltage- and ligand-gated ionic currents. Different acquisition modes, such as whole-cell patch-clamp recordings in the current or voltage clamp configuration, capacitance measurements or single channel recordings from cultured cells as well as acute brain slices are routinely performed for these purposes. Nevertheless, multipurpose transparent and adaptable software tools to perform reproducible state-of-the-art analysis of multiple experiment types and to manage larger sets of experimental data are currently unavailable. We therefore developed Biophysical Essentials (BPE) as an open-source python software for transparent and reproducible analysis of electrophysiological recordings. While initially designed to improve time consuming and repetitive analysis steps, BPE was optimized to cover entire workflows from data acquisition, preprocessing, visualization and normalization of single recordings up to stacked calculations and statistics of multiple experiments. BPE can operate with different file formats from different amplifier systems and producers. An in-process database logs all analysis steps for later review and serves as a central storage point for recordings. Statistical testing as well as advanced analysis functions like Boltzmann-fitting and dimensional reduction methods further support the researchers needs in projects involving electrophysiology techniques. Impact statementBiophysical Essentials provides fundamental support for transparent patch-clamp analysis to improve reproducibility in electrophysiology research.

neuroscience↗

IL-4 shaping glutamatergic synapse like structures for more mature iPSC derived neuron phenotypes

The prototypical pleiotropic anti-inflammatory cytokine IL-4 not only acts on immune cells but also has important roles in the nervous system mediating antinociception and neuroregeneration. Therefore, we explored the expression of IL-4, its receptors IL4RA and IL13RA1 and downstream signaling components together with morphological and functional assays as well as transcriptomic profiling in human nociceptors differentiating from induced pluripotent stem cells (iNocs). IL-4 induced de novo formation of synaptic boutons immunoreactive for vesicular glutamate transporter vGLUT1 in iNocs which express both, components of the IL-4 receptor complex (IL-4RA and IL-13RA1) and signaling machinery (Jak1/2, STAT6, PKC isoforms, translation factor EiF4E) during differentiation. Pharmacological inhibition of these translational or cellular signaling components reduced the synaptogenic effect. IL-4 induced distinct transcriptomic changes associated with biological process ontologies for "neuron projection development", "axonogenesis" and "synapse", "cellular process involved in reproduction in multicellular organism", "regulation of membrane potential" and "calcium ion transmembrane transport". This partially reflected injury-induced transcriptional changes of mouse nerve injury models which contribute to regenerative processes in peripheral nerve but possibly also to reconnecting primary afferent neurons to their projections in the spinal dorsal horn and indicates a critical role for IL-4 in the control of developing and established neuronal networks.

neuroscience↗

EntomonVR: a New Virtual Reality Game for Learning Insect Morphology

In recent years, the study of insect morphology has benefited greatly from the emergence of new digital imaging and analysis technologies such as X-ray micro-computed tomography (-CT), digital 3D reconstruction, and animation. Through interactive gaming and virtual reality, the external morphology of insects can be studied by a broad audience of both entomologists and non-specialists. EntomonVR is a serious game designed to investigate the external morphology of insects with adequate quality for the virtual reality platform. We discuss the advantages of virtual reality, introduce the EntomonVR new educational game, and conclude about future perspectives, validations, and cost-effectiveness. For game assessment, we have tested this game on 25 participants with an entomological background and improved the game based on their feedback. This study demonstrates the efficacy of virtual reality technology for an experimental learning environment in teaching the morphology of insects and the crucial needs for advancing an efficient and interactive educational program.

scientific communication and education↗

How to navigate the myosin-V motor through the actin network

Myosin-V (MyoV) is a ubiquitous motor protein that transports an astonishingly diverse set of cargos on the actin network in eukaryotes. Phosphorylation-dependent processes often regulate MyoV-mediated cargo transport, molecular details of which remain largely unknown. We previously showed that phosphorylation regulates MyoVs switching from microtubules onto actin filaments, not its motor activity. Regulation of switching at reconstituted microtubule-actin-crossings in fact sufficed to recapitulate the MyoVa-driven redistribution of pigment-organelles in amphibian melanophores. However, in those cells, MyoVa also encounter many actin-actin crossings. Here, we show that isolated MyoVa motors switch with equal probabilities at reconstituted actin-actin-crossings. Under the control of its adaptor-protein melanophilin (Mlph), however, the motor differentiates between the actin filaments at crossing points in a phosphorylation-regulated manner. Whereas phosphorylation of Mlph forced about [~]2/3 of MyoVa to ignore the intersections, dephosphorylation completely reversed this behavior and forced [~]2/3 to switch. We show that the filament-binding domain (FBD) of Mlph controls this switching behavior. This property evolved in amphibians, but not in the early vertebrate zebrafish. By protein engineering, we demonstrate that changes of a few residues are sufficient to impart actin-binding capability onto the zebrafish Mlph. We thus unmask the molecular beginnings of dual filament binding in Mlph that allow it to control the switching behavior of MyoVa at cytoskeletal crossings. We therefore propose a direct link between intracellular phosphorylation activity and the adaptor-protein, not to regulate MyoVa activity, but to navigate the motor through the entire cytoskeletal maze for correct positioning of cargo. Significance statementIn virtually all eukaryotic cells, numerous myosin motors have to navigate through an elaborate actin network for timely transport of intracellular cargo. Here, we unmask an unintuitive regulation of the myosin-Va motor that is involved in pigment organelle transport. We demonstrate that myosin-Va differentiates between the same actin filaments and displays regulated switching at reconstituted actin-actin crossings, an unexpected behavior that has been predicted from previous theoretical work. We trace this regulation back to the adaptor protein of the myosin-Va motor and show that this regulation was present in amphibian but had not evolved in the early vertebrate zebrafish. Notably, we demonstrate that the evolution of actin-binding capability is achieved by changing a few residues in the adaptor protein.

biochemistry↗