Biology subjects

Potthoff, A.

Publications and source records attributed to Potthoff, A..

4 recordsLinked to original sources

bioRxiv2026

Cisplatin-triggered sensory dysfunction in NER-defective C. elegans involves GABAergic and cholinergic signaling

Cisplatin (CisPt) is a widely used anticancer drug that causes neurotoxicity as a dose-limiting adverse effect. DNA damage contributes to CisPt-induced neurotoxicity, yet the molecular mechanisms involved remain unclear. Here, we aim to identify pathophysiological mechanisms contributing to DNA damage-driven development of sensory neuronal dysfunction using the 3R-compliant model organism Caenorhabditis elegans. To this end, we employed the nucleotide excision repair (NER)-deficient ercc-1 mutant, which shows enhanced CisPt-induced sensory dysfunction as monitored by the chemotaxis assay, to elucidate drug-induced alterations in neurotransmission and transcriptome. We found that CisPt reduces gamma-aminobutyric acid (GABA) levels in the nematode and that GABA supplementation rescues ercc-1 mutants from CisPt-evoked sensory neurotoxicity, pointing to a neuroprotective function of GABA in the context of our study. Moreover, CisPt impairs the morphological integrity of GABAergic neurons particularly in ercc-1 mutants, which again is rescued by GABA substitution. Conversely, the cholinergic agonist carbachol impairs sensory function and exacerbates the neurotoxic effects of CisPt in ercc-1 mutants, indicating detrimental effects resulting from cholinergic excitation. Transcriptome analysis revealed that CisPt treatment stimulates a broard transcriptional response, including pathways involved in the regulation of neuronal communication, including acetylcholine-mediated neurotransmission, with pronounced effects occurring in the absence of ERCC-1. Based on these finding we suggest impaired GABAergic signaling and the loss of neuronal integrity GABAergic neurons as well as excessive cholinergic excitation as key mechanisms linking CisPt-induced DNA damage in NER defective nematodes to sensory dysfunction. Hence, targeting the balance between GABAergic inhibition and cholinergic excitation is suggested to counteract sensory neurotoxicity triggered by CisPt.

pharmacology and toxicology↗

bioRxiv2026

Tensile Expansion Mass Spectrometry for single cell metabolomics imaging

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) enables the spatial mapping of endogenous biomolecules within native biological specimens; however, it remains limited in achieving single-cell resolution. While advances in instrument modifications, computational processing methods, and tissue-based sample preparation have facilitated high lateral resolutions and cellular level imaging, resolving metabolic heterogeneity at the single-cell level remains challenging for users without specific expertise or custom instrumentation. Here, we present tensile expansion mass spectrometry (TExMS), a cost-effective approach for single-cell MALDI-MSI that is compatible with commercial MSI instrumentation. TExMS utilizes highly stretchable hydrogels as a substrate for live-cell seeding, attachment, and desiccation, avoiding the need for chemical fixation and enabling the retention of both intracellular and extracellular metabolites, including media-derived components that are lost during fixation and washing. We used TExMS to expand individual cells of a human high-grade serous ovarian cancer (HGSOC) cell line and spatially map their small molecule (<800 Da) production. TExMS enabled [~]4-fold linear expansion of the hydrogel, translating to a [~]1.7-fold increase in average cell area and [~]1.3-fold increase in nuclear area and resulting in improved lateral resolution of metabolite distributions. Benchmarking against other platforms for high resolution MALDI-MSI, TExMS offered comparable spatial resolution to microgrid-enabled MALDI-MSI with 15 to 20-fold shorter acquisition times. We then used TExMS to map numerous intermediates from glycolysis, the tricarboxylic acid (TCA) cycle, and amino acid biosynthesis and probe the effects of serum starvation conditions on metabolic flux through these pathways, demonstrating a powerful use case for single-cell MALDI-MSI through TExMS. Table of Contents (TOC) O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=85 SRC="FIGDIR/small/745024v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@18f8c09org.highwire.dtl.DTLVardef@132bc4aorg.highwire.dtl.DTLVardef@1e7c2caorg.highwire.dtl.DTLVardef@a586cf_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2025

TSP1/TGF-β1 drives arachidonic acid metabolism to orchestrate neutrophil swarming

Neutrophil swarming has emerged as a conserved multicellular behaviour observed across tissues and pathological contexts. Yet, the molecular cues and the spatially coordinated cellular circuits that drive the process of neutrophil swarming leading to cluster formation remain poorly understood. Here, we combine spatial proteomics and lipid profiling in a model of urinary tract infection to define the epithelial-immune circuits driving neutrophil cluster formation. We identify thrombospondin-1 (TSP1)-mediated activation of transforming growth factor beta 1 (TGF-{beta}1) as key epithelial signal licensing neutrophil clustering and enhancing bacterial control. Spatial lipid analysis further reveals that TSP1/TGF-{beta}1 signalling locally activates arachidonic acid metabolism in epithelial neutrophils, with 5-lipoxygenase dependent leukotriene synthesis required for swarm formation and infection clearance. These findings uncover a spatially coordinated defence mechanism in which epithelial-derived TSP1/TGF-{beta}1 engages neutrophil lipid metabolism to orchestrate neutrophil swarming behaviour and reinforce antibacterial immunity. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=127 SRC="FIGDIR/small/688397v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@114ea92org.highwire.dtl.DTLVardef@345244org.highwire.dtl.DTLVardef@10520baorg.highwire.dtl.DTLVardef@1a7c0fe_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO C_FIG

immunology↗

bioRxiv2024

Histology-Guided Single-Cell Mass Spectrometry Imaging using Integrated Bright-field and Fluorescence Microscopy

The rapidly evolving field of spatial biology revolves around the analysis of cells in their native microenvironment. This analysis can include morphological features, the presence of specific antigens or gene expression. To add another layer of information, recent methodological advances in matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) now enable the untargeted analysis of lipids and metabolites at subcellular resolution. The integration of MALDI-MSI at the single-cell level with established optical modalities, however, relies on an accurate yet intricate co-registration. Here, we describe the integration of bright-field and fluorescence microscopy into a prototype ion source of a state-of-the art MALDI-MSI instrument to obtain lipid and fluorescence microscopy-derived information from the same specimen, hence with intrinsic spatial correlation. We demonstrate the potential of the combined mass spectrometric and optical single-cell analysis on three examples. This includes the visualization of intracellular lipid distributions in macrophages, the introduction of pre-MALDI immunofluorescence staining on the example of murine cerebellum, and the heterogeneity of lipid profiles of tumor infiltrating neutrophils correlated to their individual microenvironments. Overall, the achieved tight correlation of single-cell lipid profiles with morphologic features and protein expression patterns constitutes a powerful resource for cell biology.

cell biology↗