Biology subjects

Haerteis, S.

Publications and source records attributed to Haerteis, S..

5 recordsLinked to original sources

bioRxiv2026

DESI-MS-Based Analysis of Drug Distribution in Human Renal Cystic Tissue Using the Chorioallantoic Membrane (CAM) as a 3D In Vivo Model

The chorioallantoic membrane (CAM) model represents a promising three-dimensional in vivo platform for preclinical drug testing in human tissues. In this study, we investigated whether the tissue penetration and distribution of benzbromarone, a known inhibitor of the Ca2+ activated chloride channel TMEM16A and potential therapeutic agent for autosomal dominant polycystic kidney disease (ADPKD), can be successfully visualized in human renal cyst tissue cultured on the CAM. To this end, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) combined with an ultrahigh-resolution time-of-flight mass spectrometer was employed. We achieved spatially resolved molecular mapping of endogenous metabolites and lipids as well as the applied compound. MSI enabled clear differentiation between CAM and cystic tissue based on their distinct lipid profiles. Benzbromarone was reproducibly detected in the cyst specimens and exhibited selective accumulation along the cyst epithelium, which is considered the principal site of action. These observations were complemented by multivariate analyses including Uniform Manifold Approximation and Projection (UMAP), and sparse multinomial logistic zero-sum classification. The data-driven approach confirmed molecular differences between tissue types and allowed accurate classification of drug-treated and untreated regions. This study demonstrates that topically applied benzbromarone penetrates human renal cyst tissue in the CAM model and localizes to pharmacologically relevant tissue regions, notably the location of the Ca2+ activated chloride channel TMEM16A in the epithelial lining. The integration of high-resolution DESI-MSI with advanced statistical analysis provides a robust and label-free method to study drug distribution in human tissue grafts. Our findings contribute to the advancement of translational research in analytical chemistry and pharmacology.

biochemistry↗

bioRxiv2026

Cyst-type epithelial heterogeneity shapes therapeutic responsiveness in ADPKD

Autosomal dominant polycystic kidney disease (ADPKD) exhibits substantial interpatient variability in disease course and therapeutic response, but the cellular basis for this variability remains poorly understood. Here, we combine single-nucleus RNA sequencing of human cyst epithelia with machine learning-based histological analysis of >1,800 cysts to resolve three epithelial cyst types--proximal tubule-like, collecting duct-like, and mixed. These cyst types display distinct injury states, metabolic programs, and stromal microenvironments, including a mixed-cyst niche enriched for CCL2-associated inflammatory signaling. Expression of key therapeutic targets was highly cell-type specific with CFTR enriched in proximal-like epithelia, whereas AVPR2 expression was confined to AQP2-positive collecting duct-like cells. Cyst-type composition varied widely across patients and in an orthologous mouse model (Pkd1RC/RC) in which the burden of AQP2-positive cysts correlated with responsiveness to tolvaptan. These findings identify cyst-type heterogeneity as a major determinant of molecular pathway activation and predictability of therapeutic response in ADPKD.

molecular biology↗

bioRxiv2026

Staphylococcus aureus triggers isolate-specific host transcriptional responses alongside TNF-R1 regulated cell death

BackgroundStaphylococcus aureus (S. aureus) is an increasingly recognized intracellular pathogen, yet infection outcomes vary with bacterial isolate and host cell type. The mechanisms underlying these differences remain poorly understood. This study investigates how distinct intracellular S. aureus isolates influence host signaling programs and infection outcomes by modulating cell death pathways and TNF-R1 dependent regulation of host cell fates across different human cell lines. MethodsFour S. aureus isolates were analyzed for intracellular localization using transmission electron microscopy (TEM), structured illumination microscopy (SIM), serial block-face scanning electron microscopy (SBF-SEM), and imaging flow cytometry. Transcriptional reprogramming of infected U937 monocytes was examined by mRNA sequencing. Infection outcomes were characterized and compared to A549 and SaOS-2 cell lines employing Luminex cytokine assays, flow cytometry and Western blot analysis to characterize host cell death mechanisms in both wild-type and TNF-R1 deficient backgrounds. ResultsAll S. aureus isolates localized to endolysosomal and cytosolic compartments but also peri and putatively intranuclearly, revealing an unexpected intracellular niche. In U937 monocytes, infection induced a conserved stress signature alongside isolatespecific transcriptional programs divergently affecting inflammation, metabolism, and cell fate, which was markedly attenuated in response to the chronicinfection isolate EDCC 5464. Cell death outcomes were likewise isolatedependent, involving intrinsic and extrinsic apoptosis, mitochondrial depolarization, and caspase-1 activation at distinct temporal dynamics. TNFR1 loss initially delayed but exacerbated late, isolate-independent cytotoxicity, identifying TNFR1 as a key regulator of U937 infection outcome. SaOS2 and A549 cell death was far less affected by isolate or TNF-R1 deficiency. ConclusionsThese results highlight the multilayered determinants governing intracellular S. aureus survival, non-canonical intracellular localization, and host cell susceptibility. The TNF/TNF-R1 axis is identified to critically determine regulated host defense during early infection stages in a tissue-specific manner. Together with distinct isolate-driven gene expression profiles, infection risks under TNF-targeted therapies and the contribution of S. aureus heterogeneity should be considered in the design of future host-directed treatment strategies. Plain English summaryThe bacterium Staphylococcus aureus (S. aureus) often lives harmlessly in humans but can cause severe or recurrent infections when the skin barrier is broken or the immune system is weakened. A major reason for its persistence is its ability to hide inside human cells, where it is shielded from immune attacks and antibiotics. To effectively target such bacteria, it is crucial to understand that infections vary depending on both the bacterial strain and the infected cell type. Many reasons behind these differences are still puzzling. We explored how different types of S. aureus (collected from different disease types) change how human cells respond to infection. We focused on how the different strains influence the way immune cells adjust their gene activity during infection, and how a receptor called TNF-R1 is involved in managing cell death responses. Bacteria were found not only in compartments meant to destroy them but also near and even inside the cell nucleus, an unexpected location. All strains triggered a similar stress response but also distinct patterns influencing inflammation, metabolism, and cell survival. A strain linked to chronic infection caused weaker responses, suggesting greater stealth. Cells lacking TNF-R1 initially survived longer but later showed greater damage, indicating this receptors role in infection control. In lung and bone cells, these effects were less pronounced. Concludingly, S. aureus occupies unexpected niches inside human cells and uses varying survival strategies. TNF-R1 is a key regulator of host infection responses in the analyzed immune cells, highlighting that both bacterial diversity and host factors must be considered when developing targeted treatments. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=199 SRC="FIGDIR/small/723175v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@1b4214org.highwire.dtl.DTLVardef@18f4ee6org.highwire.dtl.DTLVardef@1851742org.highwire.dtl.DTLVardef@ba0359_HPS_FORMAT_FIGEXP M_FIG Peri- and intranuclear localization early after S. aureus uptake across host cell lines, with isolate-specific modulation of host fates and a critical role for TNF-R1 to mediate regulated death responses of U937 cells. At 2 hpi, intracellular S. aureus not only localizes in (LAMP-1 decorated) membrane-enclosed compartments or directly in the cytosol, but within invaginations of the nuclear surface and intranuclearly with or without being surrounded by a vesicular membrane in U937wt, SaOS-2wt, and A549wt cells. At 4 hpi, S. aureus triggers differential gene expression in (A) U937wt cells to an isolate-specific extent, with both unique and shared transcriptomic signatures across the four isolates, that is muted for the chronic infection isolate EDCC 5464. Apoptotic cell death is induced to an isolate-dependent extent involving extrinsic initiator caspase-8, intrinsic initiator caspase-9 (EDCC 5055 only), and variable effector caspase-3/-7 activity in the earlier stages of infection (6 hpi), which then barely increases (24 hpi) in U937wt cells. S. aureus-induced cell death and caspase activation is abolished in (B) U937{Delta}TNF-R1 at 6 hpi, but is significantly reinforced at 24 hpi with diminished isolate-specificity. Correspondingly, mitochondrial trans-membrane potential ({Delta}{Psi}m) is disrupted for all isolates upon TNF-R1 knockout, as well as caspase-1 activity, suggesting pyroptotic pathway activation at later stages of infection. (C) SaOS-2 wt cells show moderate caspase-3/-7 and -1 activation, while infection induces detachment of (D) A549wt cells with minimal caspase activation. Infection induces an isolate- and cell line-dependent cytokine release. Coloured arrows indicate the mean proportion of effector-positive cells ({uparrow} [~]20-40%, {uparrow} {uparrow} 40-60%, {uparrow} {uparrow} {uparrow} >60%) representing each S. aureus isolate. Grayed signaling arrows indicate the hypothesis by which TNF-R1 activation and internalization is required to kill lysosomal S. aureus via activation of anti-microbial enzymes and downstream regulated death pathway activation. Created with BioRender.com. C_FIG

microbiology↗

bioRxiv2025

Pro-endometriosis macrophage release of IL-33 is key for endometriosis pain and lesion formation

Endometriosis is a painful gynecological inflammatory disease affecting up to 10% of females. When released by sensory neurons, calcitonin gene-related peptide (CGRP) shapes immunity, a process known as neuroimmune communication. We previously showed that nociceptor-derived CGRP polarizes macrophages into pro-endometriosis macrophages (PEMs) that mediates endometrial epithelial (endo-epi) cell proliferation and pain. However, the key mediators involved in this PEM-induced cell proliferation were unknown. Using unbiased approaches, we discovered that nociceptor-derived CGRP induces PEMs to produce IL-33. IL-33 binding to its receptor ST2 is key for endometriotic lesion growth and pain during endometriosis in mice as anti-IL-33 antibody treatment reduced evoked and spontaneous pain as well as lesion size. Chemical or genetic ablation of nociceptors or macrophages also resulted in lower levels of lesion IL-33, demonstrating a neuroimmune-driven mechanism for IL-33 production during endometriosis. In humans, we found that IL-33 is correlated with increased number of glands and fibrosis in lesions and that IL-33 expression in macrophages is also associated with genetic risk of endometriosis. We also provided evidence that suggests a dual role for IL-33 in endometriosis, in which, it is initially required for lesion formation and later for lesion maintenance only, and associated pain. Therefore, targeting IL-33/ST2 signaling may effectively treat endometriosis pain.

neuroscience↗

bioRxiv2024

High-throughput differentiation of human blood vessel organoids reveals overlapping and distinct functions of the cerebral cavernous malformation proteins

Cerebral cavernous malformations (CCMs) are clusters of thin-walled enlarged blood vessels in the central nervous system that are prone to recurrent hemorrhage and can occur in both sporadic and familial forms. The familial form results from loss-of-function variants in the CCM1, CCM2, or CCM3 gene. Despite a better understanding of CCM pathogenesis in recent years, it is still unclear why CCM3 mutations often lead to a more aggressive phenotype than CCM1 or CCM2 variants. By combining high-throughput differentiation of blood vessel organoids from human induced pluripotent stem cells (hiPSCs) with a CCM1, CCM2, or CCM3 knockout, single-cell RNA sequencing, and high-content imaging, we uncovered both shared and distinct functions of the CCM proteins. While there was a significant overlap of differentially expressed genes in fibroblasts across all three knockout conditions, inactivation of CCM1, CCM2, or CCM3 also led to specific gene expression patterns in neuronal, mesenchymal, and endothelial cell populations, respectively. Taking advantage of the different fluorescent labels of the hiPSCs, we could also visualize the abnormal expansion of CCM1 and CCM3 knockout cells when differentiated together with wild-type cells into mosaic blood vessel organoids. In contrast, CCM2 knockout cells showed even reduced proliferation. These observations may help to explain the less severe clinical course in individuals with a pathogenic variant in CCM2 and to decode the molecular and cellular heterogeneity in CCM disease. Finally, the ability to differentiate blood vessel organoids in a 96-well format will further facilitate their use in drug discovery and other biomedical research studies. STATEMENTS AND DECLARATIONSO_ST_ABSConflicts of interest statementC_ST_ABSThe authors declare no competing interests. The here described protocol for high-throughput organoid synthesis has been filed as a patent application at the European Patent Office (Process number: EP24213596.0) Author contribution statementMR, DSk, and UF designed the study. DSk, VS, LM, and RAP performed most of the functional experiments. SH and TA performed the CAM assays. SR performed the immunohistochemical stainings. SB, DSi, DSk, and VS performed the confocal microscopy and high-content imaging analyses. AE, CB, and EMB performed the scRNA sequencing analysis. AW and CAH performed and analyzed the karyotyping of the hiPSC clones. DSk, RAP, VS, KC, MR, and SB analyzed the data. DSk, VS, LM, and MR prepared figures. All authors contributed to the interpretation of the results. DSk, RAP, VS, and MR drafted the manuscript, and all authors contributed to writing. Ethics statementThis study does not involve human participants or animal subjects. Availability of data and materialsAll relevant data are published within the paper and the supplementary files. ScRNA sequencing data can be accessed through the Gene Expression Omnibus (GEO) database (record number: GSE276497).

molecular biology↗