Moers, C. | bioRxiv Science

bioRxiv2025

Exploring ex vivo modulation of fibrosis in discarded human donor kidneys

IntroductionEarly-onset fibrosis limits kidney transplant success. Normothermic machine perfusion (NMP) offers a platform for targeted drug delivery directly to isolated organs, minimizing systemic effects. This study evaluated the long-term anti-fibrotic efficacy and safety of galunisertib in discarded human kidneys perfused ex vivo. MethodsTwelve discarded human kidneys underwent 4 hours of oxygenated hypothermic perfusion followed by 6 hours of NMP with galunisertib or vehicle (n=6). Precision-cut kidney slices (PCKS) were then cultured for 48 hours with either continued or discontinued galunisertib exposure. Endpoints included fibrosis-related mRNA expression and pharmacokinetics. ResultsGalunisertib did not negatively affect renal function during NMP. Continued exposure in PCKS significantly attenuated fibrosis-related mRNA expression, including SERPINE1 (p=0.0046), TGF-{beta} (p=0.0168), FN1 (p=0.0269) and ACTA2 (p=0.0014) after 48 hours. The discontinuation of treatment did not exhibit the same anti-fibrotic effects. ConclusionGalunisertib was safely administered during NMP and steadily excreted via the urine. NMP showed to be a promising platform for safe targeted anti-fibrotic therapy delivery, offering potential to improve graft quality. When treatment was sustained, galunisertib induced a modest reduction in fibrosis-related mRNA expression over 48 hours of tissue incubation. Further studies are needed to optimize delivery strategies and evaluate the impact of prolonged therapeutic exposure.

pharmacology and toxicology↗

bioRxiv2024

End of preservation normothermic machine perfusion of porcine kidneys after ischaemic injury reprograms metabolism and induces fibrosis after transplant despite unchanged function: insights from the renal proteome.

Normothermic machine perfusion (NMP) after initial hypothermic preservation of donor kidneys prior to transplantation is becoming a clinical reality, but the precise molecular mechanisms through which the graft is impacted remain only partially characterised. Using an unbiased proteomic methodology, we found that auto transplantation of is chaemically injured porcine kidneys resulted in an activation of the stress response 14 days after transplantation, as well as in selective changes in the proteins responsible for the metabolism of organic acids. The addition of 4 hours of NMP at the end of organ preservation (endNMP) resulted in coordinated changes to the renal proteome at 14 days when compared with the effect of transplant after preservation by hypothermic machine perfusion alone: most notably increased fibrosis and widespread additional reprogramming of metabolism. These findings were supported by intersection with single cell transcriptomics data which suggested an enrichment of proteins predominantly expressed in fibroblasts in kidneys with end of preservation NMP 14 days post-transplant compared to healthy kidneys. Our data showed that the addition of endNMP to existing preservation strategies resulted in a different molecular phenotype after transplantation, despite unchanged filtration function. In addition to potentially conferring benefits, NMP may also result in potentially detrimental molecular changes and thus protocols should be carefully evaluated to derive optimal clinical outcomes.

physiology↗