Biology subjects

Küchler, J.

Publications and source records attributed to Küchler, J..

4 recordsLinked to original sources

bioRxiv2025

MyeliMAP: Studying Oligodendrocyte Function in Brain Networks

Oligodendrocytes are the myelinating glia of the central nervous system (CNS), essential for rapid signal propagation, metabolic support, and neuronal health. While rodent-based cultures and organoid systems have provided insights into oligodendrocyte biology, they fall short of capturing human-specific features of myelination or integrating structural and functional readouts. Here, we present MyeliMAP (Myelination MAPping), a human pluripotent stem cell (hPSC) -derived microphysiological and electrophysiological platform that enables robust modeling of CNS myelination. The system combines inducible hPSC-derived neurons and oligodendrocytes in a custom-engineered microfluidic microstructure designed to mimic the developing brain microenvironment, promoting spatially organized axon-glia interactions and controlled myelin sheath formation. Within six weeks, we demonstrate myelin formation and maturation by immunofluorescence and ultrastructural validation using transmission electron microscopy (TEM), confirming compact multilayered wrapping of human axons. Importantly, the microstructure is directly integrated with a high-density microelectrode array (HD-MEA), enabling real-time, long-term functional assessment of network activity and myelin-dependent changes in signal conduction. This allowed us to demonstrate that oligodendrocyte-based myelinated neurons display enhanced conduction velocity of action potentials compared to neuron monocultures. Moreover, the presence of oligodendrocytes stabilized the temporal neuronal network activity by reducing variability in firing patterns and enhancing synchrony across the culture. This dual structure-function approach surpasses static end-point analyses by coupling morphological validation with dynamic, quantitative measurements of maturing circuit physiology. MyeliMAP provides a reproducible, human-relevant platform to dissect neuron-glia interactions and accelerate discovery of remyelination-promoting strategies for CNS disease.

neuroscience↗

bioRxiv2025

Quantitative analysis of proteomic changes in monoclonal MDCK cell lines infected with human influenza A virus

AbstractSuspension MDCK cells are a substrate for producing influenza A virus (IAV) and typically show very high virus yields compared to other animal cells. Due to the significant heterogeneity within cell populations, studying and comparing clonal cell lines with regard to specific properties, such as superior growth or higher productivity, could facilitate process optimization. In this study, we analyzed the expressed proteins of clonal cell lines to identify intrinsic characteristics of effective IAV producers. We compared proteome changes in two IAV-infected monoclonal suspension MDCK cell lines: C59, a low-yield IAV producer with fast cell growth and small cell diameter, and C113, a high-yield IAV producer with average cell growth and large cell diameter. We examined growth rate, size, metabolism and IAV production. A total of 5177 host cell proteins were detected in both cell lines using DIA-PASEF mode with a TimsTOFpro mass spectrometer. Analysis of the differentially expressed proteins revealed that fatty acid oxidation and branched-chain amino acid degradation were upregulated in highly productive cells. In contrast, steroid biosynthesis and DNA replication were more active in faster-growing cells. Following infection, 122 proteins were significantly upregulated (p<0.05, log2-fold change [≥]1) in the high-producing cell line. These proteins were associated with membrane trafficking, interactions with the IAV-NS1 protein and virus production. Additionally, 98 proteins associated with antiviral pathways such as the proto-oncogenic receptor tyrosine kinase MET and tumor necrosis factor (TNF) signaling were downregulated (p<0.05, log2-fold change [≤]1). In the cell line that produced lower IAV titers, 77 proteins were downregulated and 57 were upregulated after infection. RNA metabolism appeared to be downregulated, while the tricarboxylic acid (TCA) cycle and the stress response were both upregulated. In the high-yield C113 clone, only proteins associated with apoptosis and the target of rapamycin kinase (TOR) were expressed following infection. This may indicate a more effective release of virus particles. A comparison of intracellular IAV protein levels demonstrated that M1 and NA levels were 4-fold and 8-fold higher, respectively, for the high-yield C113 cell line. These findings again suggest better virus release.

molecular biology↗

bioRxiv2025

An Integrated In Vitro Platform and Biophysical Modeling Approach for Studying Synaptic Transmission in Isolated Neuronal Pairs

Studying synaptic transmission and plasticity is facilitated in experimental systems that isolate individual neuronal connections. We developed an integrated platform combining polydimethylsiloxane (PDMS) microstructures with high-density microelectrode arrays to isolate and record single neuronal pairs from human induced pluripotent stem cell (hiPSC)-derived neurons. The system maintained hundreds of parallel neuronal pairs for over 100 days, demonstrating functional synapses through pharmacological validation and long-term potentiation studies. We coupled this platform with a biophysical Hodgkin-Huxley model and simulation-based inference to extract mechanistic parameters from electrophysiological data. The analysis of long-term potentiation stimulation using a biophysical model revealed (-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) AMPA and (N-methyl-D-aspartate) NMDA receptor-specific alterations, providing quantitative insights into synaptic plasticity mechanisms. This integrated approach represents the first system combining isolated synaptic pairs, long-term stability, and mechanistic modeling, offering unprecedented opportunities for studying human synaptic function and plasticity.

neuroscience↗

bioRxiv2024

Engineered biological neural networks as basic logic operators

We present an in vitro neuronal network with controlled topology capable of performing basic Boolean computations, such as NAND and OR. Neurons cultured within polydimethylsiloxane (PDMS) microstructures on high-density microelectrode arrays (HD-MEAs) enable precise interaction through extracellular voltage stimulation and spiking activity recording. The architecture of our system allows for creating non-linear functions with two inputs and one output. Additionally, we analyze various encoding schemes, comparing the limitations of rate coding with the potential advantages of spike-timing-based coding strategies. This work contributes to the advancement of hybrid intelligence and biocomputing by offering insights into neural information encoding and decoding with the potential to create fully biological computational systems.

neuroscience↗