Biology subjects

Marx, U.

Publications and source records attributed to Marx, U..

7 recordsLinked to original sources

bioRxiv2026

An Integrated Analysis of GLP-1R Agonist Mechanisms: Addressing Study Variations in Heterogeneous Cell Systems

Experimental cell systems support the development of pharmacological therapies such as glucagon-like peptide-1 receptor agonists (GLP-1RAs). However, their utility in drug discovery is limited due to study variability, which complicates formation of unified conclusions based on all available data. To address this, we conducted a comprehensive analysis of the GLP-1RA exenatide, incorporating 16 new and five pre-existing mono- or co-culture studies of human liver and pancreatic models. We employed a new pragmatic model-based approach designed to handle the common situation of heterogeneous in vitro datasets with few replicates per condition. All studies are jointly explained (disagreement<{chi}{superscript 2}-limit; 542<732), thereby providing a unified conclusion based on all studies. This work links in vitro biology to clinically relevant mechanisms, such as exenatides effect on glucose-insulin interplay, and predicts previously undescribed inter-study variabilities. Independent validation confirms predictive performance (64<83). Our new integrative approach enhances the utility of experimental cell systems in preclinical drug discovery.

systems biology↗

bioRxiv2025

M4 drug discovery: human drug predictions from integrated pre-clinical insights exemplified with a GLP1-R agonist

A major recent breakthrough in the treatment of type 2 diabetes has been the development of glucagon-like peptide-1 receptor agonists (GLP-1RAs). However, current translational frameworks struggle to predict the clinical outcomes of these drugs from preclinical data. There are several reasons for this struggle, which are generic for many drugs: GLP-1RAs act through multi-timescale mechanisms in which short-term effects propagate into long-term changes; no single preclinical system can capture all their effects in humans; and mechanistic extrapolation requires modelling numerous whole-body biological processes. To address this gap, we present a new extrapolation approach, M4 drug discovery, and retrospectively apply it to the GLP-1RA exenatide in a manner that is generalisable to other drugs. The method integrates: Multi-level data (cellular to whole-body), Multi-timescale data (minutes to months), Multi-species data (e.g., rodents to humans), and Mechanistic knowledge. In this study, we integrate human cell and animal data with drug-free human studies to successfully predict human pharmacokinetics (cost < {chi}2, p=0.05; 64 < 97) and the outcomes of a 30-week clinical trial (36 < 45). We found that integrating information across the four M4 axes improved predictive performance and physiological relevance: multi-species data inform pharmacokinetics, human cell data provide human population- and donor-specific potency estimates, animal data reveal additional drug effects not observable in cell cultures, and the multi-timescale mathematical modelling enables short-term effects of exenatide and meals to inform long-term changes in insulin sensitivity. This work provides new tools for drug extrapolations, supporting the community towards safer and more informed preclinical-to-clinical drug extrapolations.

systems biology↗

bioRxiv2025

New glucose-abstaining Chlorella algae doubles mammalian cell culture longevity, boosts performance and drops serum needs enabling scaled applications.

Mammalian cell culture technologies are crucial for recombinant protein production, organoid generation, medical applications, and the generation of in vitro cultivated meat. However, they are limited by high costs, vascular O2 provision, and the resultant inhibition of 3D tissue formation. Effective media usage along with oxygenation and waste management to extend culture health and longevity are key to improving all three. Microalgae, utilizing organic or inorganic CO2, produce O2 from light which complements oxygen-consuming and CO2-respiring mammalian cells and tissue culture. However, common microalgal cultivation conditions differ in temperature and salinity from mammalian cell cultivation environments, making co-cultivation short-lived and challenging. We screened several different microalgae species to identify locally isolated Chlorella BDH-1 as candidate that has high growth rates in mammalian culture conditions while, unlike other Chlorella species, does not compete for glucose as an energy source. In mammalian cell co-culture, BDH1 reduces cellular waste products, stabilizes pH, doubles culture longevity, increases growth performance up to 80%, and reduces expensive and ethically challenging foetal bovine serum requirements. Chlorella BDH-1 was also non-inflammatory and tolerant of clinical antibiotics. Collectively, mammalian cell/BDH1 co-cultivation improves tissue culture health and reduces costs, paving the path for applications in the biotechnology and medical sectors.

cell biology↗

bioRxiv2023

Diseased human pancreas and liver microphysiological system for preclinical diabetes research

Current research on metabolic disorders such as type 2 diabetes relies on animal models because multi-organ diseases cannot be well studied with the standard in vitro assays. Here, we connect models of key metabolism organs, pancreas and liver, on a microfluidic chip to enable diabetes research in a human-based preclinical system. Aided by mechanistic mathematical modelling, we developed a two-organ microphysiological system (MPS) that replicates clinically-relevant phenotypes of diabetic dysregulation both in the liver and pancreas compartments. Exposure to hyperglycemia and high cortisone created a diseased pancreas-liver MPS which displayed beta-cell dysfunction, steatosis, elevated ketone-body secretion, increased glycogen storage, and upregulated gluconeogenic machinery. In turn, normoglycemia and physiological cortisone concentration maintained glucose tolerance and stable liver and beta-cell functions. This method was evaluated for repeatability in two laboratories and was effective in multiple pancreatic islet donors. The model also provides a platform to identify new therapeutic targets as demonstrated with a liver-secreted IL-1R2 protein that induced islet proliferation.

cell biology↗

bioRxiv2021

Integrated experimental-computational analysis of a liver-islet microphysiological system for human-centric diabetes research

Microphysiological systems (MPS) are powerful tools for emulating human physiology and replicating disease progression in vitro. MPS could be better predictors of human outcome than current animal models, but mechanistic interpretation and in vivo extrapolation of the experimental results remain significant challenges. Here, we address these challenges using an integrated experimental-computational approach. This approach allows for in silico representation and predictions of glucose metabolism in a previously reported MPS with two organ compartments (liver and pancreas) connected in a closed loop with circulating medium. We developed a computational model describing glucose metabolism over 15 days of culture in the MPS. The model was calibrated on an experiment-specific basis using data from seven experiments, where single-liver or liver-islet cultures were exposed to both normal and hyperglycemic conditions resembling high blood glucose levels in diabetes. The calibrated models reproduced the fast (i.e. hourly) variations in glucose and insulin observed in the MPS experiments, as well as the long-term (i.e. over weeks) decline in both glucose tolerance and insulin secretion. We also investigated the behavior of the system under hypoglycemia by simulating this condition in silico, and the model could correctly predict the glucose and insulin responses measured in new MPS experiments. Last, we used the computational model to translate the experimental results to humans, showing good agreement with published data of the glucose response to a meal in healthy subjects. The integrated experimental-computational framework opens new avenues for future investigations toward disease mechanisms and the development of new therapies for metabolic disorders.

systems biology↗

bioRxiv2018

Bone marrow-on-a-chip: Emulating the human bone marrow

Multipotent hematopoietic stem and progenitor cells HSPC reside in specialized stem cell niches within the bone marrow, that provide a suitable microenvironment for lifelong maintenance of the stem cells. Meaningful in vitro models recapitulating the in vivo stem cell niche biology can be employed for both basic research as well as for applied sciences and represent a powerful tool to reduce animal tests in preclinical studies. Recently we published the generation of an in vitro bone marrow niche model, capable of long-term cultivation of HSC based on an organ-on-a-chip platform. This study provides a detailed analysis of the 3D culture system including matrix environment analysis by SEM, transcriptome analysis and system intrinsic differentiation induction. Furthermore, the bone marrow on a chip model can serve to multiply and harvest HSPC, since repeated cell removal not compromised the functionality of the culture system. The prolongation of the culture time to 8 weeks demonstrate the capacity to apply the model in repeated drug testing experiments. The quality of the presented system is emphasized by the differentiation capacity of long-term cultivated HSPC in vitro and in vivo. Transplanted human HSPC migrated actively into the bone marrow of irradiated mice and contributed to the long-term reconstitution of the hematopoietic system after four and eight weeks of in vitro cultivation.\n\nThe introduced system offers a multitude of possible applications to address a broad spectrum of questions regarding HSPC, the corresponding bone marrow niche biology, and pathological aberrations.

bioengineering↗

bioRxiv2018

Towards an autologous iPSC-derived patient-on-a-chip

Microphysiological systems are fundamental for progressing towards a global paradigm shift in drug development through the generation of patient-on-a-chip models. An increasing number of single- and multi-organ systems have been adopted by the pharmaceutical and cosmetic industries for predictive substance testing. These models run on heterogeneous tissues and cell types from different donors. However, a patient is an individual. Therefore, patient-on-a-chip systems need to be built from tissues from one autologous source. Individual on-chip organ differentiation from a single induced pluripotent stem cell source could provide a solution to this challenge.\n\nWe designed a four-organ chip based on human physiology. It enables the interconnection of miniaturized human intestine, liver, brain and kidney equivalents. All four organ models were predifferentiated from induced pluripotent stem cells from the same healthy donor and integrated into the microphysiological system. The cross talk led to further differentiation over a 14-day cultivation period under pulsatile blood flow conditions in one common medium deprived of growth factors. This model platform will pave the way for disease induction and subsequent drug testing.

bioengineering↗