Biology subjects

van Leeuwen, L. L.

Publications and source records attributed to van Leeuwen, L. L..

3 recordsLinked to original sources

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

An iterative design approach to development of an ex-vivo normothermic multivisceral perfusion platform

Challenges in normothermic machine perfusion (NMP) remain, particularly concerning the duration for which individual organs can be safely preserved. We hypothesize that optimal preservation can be achieved by perfusing organs together in a multivisceral block. Therefore, our aim was to establish a platform for ex vivo multivisceral organ perfusion. Multivisceral grafts containing the liver, kidneys, pancreas, spleen and intestine were obtained from Yorkshire pigs. Three generation (gen) setups were tested during the iterative design process, and minor changes were made throughout. Gen1 (n=4) used a custom-designed single perfusion circuit. Gen2 (n=3) employed a dual perfusion circuit. Gen3 (n=4) featured a single perfusion circuit with an optimized basin and reservoir. Grafts underwent NMP using an autologous blood-based perfusate, while hemostatic parameters and function were assessed. With each iteration, aortic flow improved, resistance decreased, urine output increased, oxygen consumption rose, perfusate lactate levels dropped, and pH stability improved. Cellular injury trended lower in Gen3. Histological evaluation demonstrated minimal differences in Gen2 and 3. We demonstrate the feasibility of abdominal multivisceral NMP for up to 8 hours. Adequate arterial flow, stable perfusate pH, and high oxygen consumption in setup 3 indicate organ viability. Multivisceral perfusion may serve as a platform for long-term NMP.

physiology↗

bioRxiv2022

Targeted delivery of galunisertib attenuates fibrogenesis in an integrated ex vivo renal transplant and fibrosis model

Normothermic machine perfusion is an emerging preservation technique for kidney allografts to reduce post-transplant complications, including interstitial fibrosis and tubular atrophy. This technique, however, could be improved by adding antifibrotic molecules to perfusion solutions. We established Machine perfusion and Organ slices as a Platform for Ex vivo Drug delivery (MOPED), to explore fibrogenesis suppression strategies. We perfused porcine kidneys ex vivo with galunisertib--a potent inhibitor of the transforming growth factor beta signaling pathway. To determine whether effects persisted, we also cultured precision-cut tissue slices prepared from the respective kidneys. Galunisertib supplementation improved the general viability, without negatively affecting renal function or elevating levels of injury markers or byproducts of oxidative stress. Galunisertib also reduced inflammation and more importantly, strongly suppressed the onset of fibrosis, especially when the treatment was continued in slices. Our results illustrate the value of targeted drug delivery, using isolated organ perfusion, for reducing post-transplant complications. One Sentence SummaryGalunisertib supplementation during normothermic machine perfusion attenuates fibrogenesis without compromising renal function.

bioengineering↗