IntroductionThe potential for drug-induced gastrointestinal (GI) toxicity is significant, since the GI tract is one of the first barriers which come in to contact with oral drugs. In pharmaceutical research, the complex behavior of human intestinal cells is traditionally investigated using 2D cultures, in which one cell type grows under static conditions. With the development of advanced microphysiological systems (MPS) more in vivo like conditions can be generated which increase the physiological nature and also the predictive validity of these models. Caco-2 cells are known for their capability to build tight junctions. These connections are responsible for the maintenance of intestinal homeostasis and can be used as a specific safety endpoint, by measuring the Trans Epithelial Electrical Resistance (TEER), for the investigation of drug-induced GI toxicity. Compared to a widely used Caco-2 cell 2D Transwell model, the advanced MPS model (Mimetas OrganoPlate®) allows for the recapitulation of the enterocyte cell layer of the intestinal barrier as the Caco-2 cells grow in a tubular structure through which the medium continuously flows.MethodsThe OrganoPlate® intestinal model was qualified to be implemented as a routine test system for the early prediction of drug-induced GI toxicity based on the measurement of the tightness of the cell layer by measuring changes in the TEER. For this qualification 23 well known compounds as well as a positive, negative and solvent control were selected. The compounds were selected based on their known effect on the GI system (chemotherapeutics, tight junction disruptor, liver toxins, controls, NSAIDs and a mixed group of drugs).ResultsThe TEER values were measured 4 h and 24 h after treatment. In parallel the cell viability was determined after 24 h to be able to distinguish between an unspecific cytotoxic effect or direct tight junction damage. Overall, from the 23 tested compounds, 15 showed the expected outcome, i.e., the compound led to a decrease of the TEER for the positive control compounds, or the TEER value remained stable after treatment with non-GI-toxic compounds.ConclusionIn summary, this MPS model allowed the recapitulation of the human intestinal GI barrier and will enable a faster and more robust assessment of drug-induced damage in the GI tract.
Metabolic dysfunction-associated steatotic liver disease (MASLD) is a worldwide health epidemic with a global occurrence of approximately 30%. The pathogenesis of MASLD is a complex, multisystem disorder driven by multiple factors, including genetics, lifestyle, and the environment. Patient heterogeneity presents challenges in developing MASLD therapeutics, creating patient cohorts for clinical trials, and optimizing therapeutic strategies for specific patient cohorts. Implementing pre-clinical experimental models for drug development creates a significant challenge as simple in vitro systems and animal models do not fully recapitulate critical steps in the pathogenesis and the complexity of MASLD progression. To address this, we implemented a precision medicine strategy that couples the use of our liver acinus microphysiology system (LAMPS) constructed with patient-derived primary cells. We investigated the MASLD-associated genetic variant patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 (I148M variant) in primary hepatocytes as it is associated with MASLD progression. We constructed the LAMPS with genotyped wild-type and variant PNPLA3 hepatocytes, together with key non-parenchymal cells, and quantified the reproducibility of the model. We altered media components to mimic blood chemistries, including insulin, glucose, free fatty acids, and immune-activating molecules to reflect normal fasting (NF), early metabolic syndrome (EMS), and late metabolic syndrome (LMS) conditions. Finally, we investigated the response to treatment with resmetirom, an approved drug for metabolic syndrome-associated steatohepatitis (MASH), the progressive form of MASLD. This study, using primary cells, serves as a benchmark for studies using “patient biomimetic twins” constructed with patient induced pluripotent stem cell (iPSC)-derived liver cells using a panel of reproducible metrics. We observed increased steatosis, immune activation, stellate cell activation, and secretion of pro-fibrotic markers in the PNPLA3 GG variant compared to the wild-type CC LAMPS, consistent with the clinical characterization of this variant. We also observed greater resmetirom efficacy in the PNPLA3 wild-type CC LAMPS compared to the GG variant in multiple MASLD metrics, including steatosis, stellate cell activation, and the secretion of pro-fibrotic markers. In conclusion, our study demonstrates the capability of the LAMPS platform for the development of MASLD precision therapeutics, enrichment of patient cohorts for clinical trials, and optimization of therapeutic strategies for patient subgroups with different clinical traits and disease stages.
Targeting the tumor microenvironment (TME) is an attractive strategy for cancer therapy, as tumor cells in vivo are surrounded by many different influential cell types, with complex interactions strongly affecting tumor progression and therapeutic outcome. Cancer-associated fibroblasts (CAFs) represent an abundant stromal cell type in the TME that modulate tumor development by exerting an immunosuppressive effect to influence effector immune cell activation. One promising target for TME-directed therapy is the CAF marker fibroblast activation protein-α (FAP). In this study, we employ a multicellular three-dimensional (3D) spheroid model, including tumor cells, fibroblast cells, and naïve T cells and could observe a protective effect of fibroblasts on tumor cells. Subsequently, we demonstrate that fibroblasts express FAP at differing expression levels in two-dimensional (2D) versus 3D cells. Lastly, we show that in a triple-culture of tumor cells, T cells and fibroblasts, the simultaneous assembly of fibroblasts using the high-affinity ligand oncoFAP with an engineered α-CD3-scFv-Fc-dextran-oncoFAP construct resulted in effective T cell activation to augment immunogenicity. Overall, this model can be routinely used for preclinical screening to study the effects of fibroblasts on the TME in vitro.