Spruck, C. | bioRxiv Science

bioRxiv2025

Mouse precision-cut liver and kidney slices: an optimized ex vivo model for acute toxicity testing

As excretion organs, the kidneys and liver are exposed to high concentrations of potentially toxic substances. While animal models remain the gold standard for organ-specific toxicity testing, alternative ex vivo approaches are essential to align with the 3R principles (refinement, reduction, replacement). Precision-cut tissue slices (PCTS) retain native tissue architecture, cellular heterogeneity, the interplay of different cell types, and metabolic capacity, offering a promising link between in vitro and in vivo models. Here, we aimed to establish an optimized protocol for preparing and culturing precision-cut kidney and liver slices (PCKS and PCLS) from mice for use in substance-oriented toxicological tests. Key parameters - including slice thickness, media composition, oxygenation, glucose levels, and incubation time - were refined to maintain tissue viability and metabolic function. Five known toxins - acetaminophen, cyclosporin A, cisplatin, arsenic trioxide, and aristolochic acid I - were tested. While PCKS showed comparable sensitivity to established kidney cell lines, PCLS achieved IC50 values closely matching in vivo toxicity data. High reproducibility across different experimenters was achieved, highlighting the robustness of the model. In conclusion, this ex vivo system provides a valuable, reproducible, and ethically approved platform for acute nephrotoxicity and hepatotoxicity testing, supporting preclinical drug screening and potentially reducing reliance on animal experiments.

pharmacology and toxicology↗

bioRxiv2024

SUV39H1 Preserves Cancer Stem Cell Chromatin State and Properties in Glioblastoma

Of the more than 100 types of brain cancer, glioblastoma (GBM) is the deadliest. As GBM stem cells (GSCs) are considered to be responsible for therapeutic resistance and tumor recurrence, effective targeting and elimination of GSCs could hold promise for preventing GBM recurrence and achieving potential cures. We show here that SUV39H1, which encodes a histone-3, lysine-9 methyltransferase, plays a critical role in GSC maintenance and GBM progression. Upregulation of SUV39H1 was observed in GBM samples compared to normal brain tissues, and knockdown of SUV39H1 in patient-derived GSCs impaired their proliferation and stemness. Single-cell RNA-seq analysis demonstrated restricted expression of SUV39H1 is in GSCs relative to non-stem GBM cells, likely due to super-enhancer-mediated transcriptional activation, while whole cell RNA-seq analysis revealed that SUV39H1 regulates G2/M cell cycle progression, stem cell maintenance, and cell death pathways in GSCs. By integrating the RNA-seq data with ATAC-seq (assay for transposase-accessible chromatin followed by sequencing), we further demonstrated altered chromatin accessibility in key genes associated with these pathways following SUV39H1 knockdown. Treatment with chaetocin, a SUV39H1 inhibitor, mimicked the functional effects of SUV39H1 knockdown in GSCs and sensitized GSCs to the GBM chemotherapy drug temozolomide. Furthermore, targeting SUV39H1 in vivo using a patient-derived xenograft model for GBM inhibited GSC-driven tumor formation. This is the first report demonstrating a critical role for SUV39H1 in GSC maintenance. SUV39H1-mediated targeting of GSCs could enhance the efficacy of existing chemotherapy, presenting a promising strategy for improving GBM treatment and patient outcomes. HighlightsO_LISUV39H1 is upregulated in GBM, especially GSCs C_LIO_LITargeting SUV39H1 disrupts GSC maintenance and sensitizes GSCs to TMZ C_LIO_LITargeting SUV39H1 alters chromatin accessibility at cell cycle and stemness genes C_LIO_LITargeting SUV39H1 suppresses GSC-driven tumors in a patient-derived xenograft model C_LI

cancer biology↗