Digital pathology with artificial intelligence analysis provides insight to the efficacy of anti-fibrotic compounds in human 3D MASH model

Metabolic dysfunction-associated steatohepatitis (MASH) is a severe liver disease characterized by lipid accumulation, inflammation and fibrosis. The development of MASH therapies has been hindered by the lack of human translational models and limitations of analysis techniques for fibrosis. The MASH three-dimensional (3D) InSight™ human liver microtissue (hLiMT) model recapitulates pathophysiological features of the disease. We established an algorithm for automated phenotypic quantification of fibrosis of Sirius Red stained histology sections of MASH hLiMTs model using a digital pathology quantitative single-fiber artificial intelligence (AI) FibroNest™ image analysis platform. The FibroNest™ algorithm for MASH hLiMTs was validated using anti-fibrotic reference compounds with different therapeutic modalities-ALK5i and anti-TGF-β antibody. The phenotypic quantification of fibrosis demonstrated that both reference compounds decreased the deposition of fibrillated collagens in alignment with effects on the secretion of pro-collagen type I/III, tissue inhibitor of metalloproteinase-1 and matrix metalloproteinase-3 and pro-fibrotic gene expression. In contrast, clinical compounds, Firsocostat and Selonsertib, alone and in combination showed strong anti-fibrotic effects on the deposition of collagen fibers, however less pronounced on the secretion of pro-fibrotic biomarkers. In summary, the phenotypic quantification of fibrosis of MASH hLiMTs combined with secretion of pro-fibrotic biomarkers and transcriptomics represents a promising drug discovery tool for assessing anti-fibrotic compounds.

A 3D primary human cell-based in vitro model of non-alcoholic steatohepatitis for efficacy testing of clinical drug candidates

Non-alcoholic steatohepatitis (NASH) is a progressive and severe liver disease, characterized by lipid accumulation, inflammation, and downstream fibrosis. Despite its increasing prevalence, there is no approved treatment yet available for patients. This has been at least partially due to the lack of predictive preclinical models for studying this complex disease. Here, we present a 3D in vitro microtissue model that uses spheroidal, scaffold free co-culture of primary human hepatocytes, Kupffer cells, liver endothelial cells and hepatic stellate cells. Upon exposure to defined and clinically relevant lipotoxic and inflammatory stimuli, these microtissues develop key pathophysiological features of NASH within 10 days, including an increase of intracellular triglyceride content and lipids, and release of pro-inflammatory cytokines. Furthermore, fibrosis was evident through release of procollagen type I, and increased deposition of extracellular collagen fibers. Whole transcriptome analysis revealed changes in the regulation of pathways associated with NASH, such as lipid metabolism, inflammation and collagen processing. Importantly, treatment with anti-NASH drug candidates (Selonsertib and Firsocostat) decreased the measured specific disease parameter, in accordance with clinical observations. These drug treatments also significantly changed the gene expression patterns of the microtissues, thus providing mechanisms of action and revealing therapeutic potential. In summary, this human NASH model represents a promising drug discovery tool for understanding the underlying complex mechanisms in NASH, evaluating efficacy of anti-NASH drug candidates and identifying new approaches for therapeutic interventions.

Utility of spherical human liver microtissues for prediction of clinical drug-induced liver injury

Drug-induced liver injury (DILI) continues to be a major source of clinical attrition, precautionary warnings, and post-market withdrawal of drugs. Accordingly, there is a need for more predictive tools to assess hepatotoxicity risk in drug discovery. Three-dimensional (3D) spheroid hepatic cultures have emerged as promising tools to assess mechanisms of hepatotoxicity, as they demonstrate enhanced liver phenotype, metabolic activity, and stability in culture not attainable with conventional two-dimensional hepatic models. Increased sensitivity of these models to drug-induced cytotoxicity has been demonstrated with relatively small panels of hepatotoxicants. However, a comprehensive evaluation of these models is lacking. Here, the predictive value of 3D human liver microtissues (hLiMT) to identify known hepatotoxicants using a panel of 110 drugs with and without clinical DILI has been assessed in comparison to plated two-dimensional primary human hepatocytes (PHH). Compounds were treated long-term (14 days) in hLiMT and acutely (2 days) in PHH to assess drug-induced cytotoxicity over an 8-point concentration range to generate IC₅₀ values. Regardless of comparing IC₅₀ values or exposure-corrected margin of safety values, hLiMT demonstrated increased sensitivity in identifying known hepatotoxicants than PHH, while specificity was consistent across both assays. In addition, hLiMT out performed PHH in correctly classifying hepatotoxicants from different pharmacological classes of molecules. The hLiMT demonstrated sufficient capability to warrant exploratory liver injury biomarker investigation (miR-122, HMGB1, α-GST) in the cell-culture media. Taken together, this study represents the most comprehensive evaluation of 3D spheroid hepatic cultures up to now and supports their utility for hepatotoxicity risk assessment in drug discovery.

A 3D-microtissue-based phenotypic screening of radiation resistant tumor cells with synchronized chemotherapeutic treatment

Background

Radiation resistance presents a challenge to the effective treatment of cancer. If therapeutic compounds were capable of resensitizing resistant tumours then a concurrent chemo-radiation treatment could be used to overcome radiation resistance.

Methods

We have developed a phenotypic assay to investigate the response of radiation resistant breast cancer cells grown in 3D-microtissue spheroids to combinations of radiation and established chemotherapeutic drugs. The effects were quantified by real time high content imaging of GFP detection area over 14 days. Ten established chemotherapeutic drugs were tested for their ability to enhance the effects of radiation.

Results

Of ten analysed chemotherapeutics, vinblastine was the most effective compound, with docetaxel and doxorubicine being less effective in combination with radiation. To investigate the response in a model closer to the in vivo situation we investigated the response of heterotypic 3D microtissues containing both fibroblasts and breast cancer cells. Drug treatment of these heterotypic 3D cultures confirmed treatment with radiation plus vinblastine to be additive in causing breast cancer growth inhibition. We have validated the screen by comparing radiation sensitizing effects of known chemotherapeutic agents. In both monotypic and heterotypic models the concurrent treatment of vinblastine and radiation proved more effective inhibitors of mammary cancer cell growth. The effective concentration range of both vinblastine and radiation are within the range used in treatment, suggesting the 3D model will offer a highly relevant screen for novel compounds.

Conclusions

For the first time comfortable 3D cell-based phenotypic assay is available, that allows high throughput screening of compounds with radiation therapy modulating capacity, opening the field to drug discovery.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1481-9) contains supplementary material, which is available to authorized users.

An RGD-restricted substrate interface is sufficient for the adhesion, growth and cartilage forming capacity of human chondrocytes

This study aimed at testing whether an RGD-restricted substrate interface is sufficient for adhesion and growth of human articular chondrocytes (HAC), and whether it enhances their post expansion chondrogenic capacity. HAC/substrate interaction was restricted to RGD by modifying tissue culture polystyrene (TCPS) with a poly(ethylene glycol) (PEG) based copolymer system that renders the surface resistant to protein adsorption while at the same time presenting the bioactive RGD-containing peptide GCRGYGRGDSPG (RGD). As compared to TCPS, HAC cultured on RGD spread faster (1.9-fold), maintained higher type II collagen mRNA expression (4.9-fold) and displayed a 19% lower spreading area. On RGD, HAC attachment efficiency (66±10%) and proliferation rate (0.56±0.04 doublings/day), as well as type II collagen mRNA expression in the subsequent chondrogenic differentiation phase, were similar to those of cells cultured on TCPS. In contrast, cartilaginous matrix deposition by HAC expanded on RGD was slightly but consistently higher (15% higher glycosaminoglycan-to-DNA ratio). RDG (bioinactive peptide) and PEG (no peptide ligand) controls yielded drastically reduced attachment efficiency (lower than 11%) and proliferation (lower than 0.20 doublings/day). Collectively, these data indicate that restriction of HAC interaction with a substrate through RGD peptides is sufficient to support their adhesion, growth and maintenance of cartilage forming capacity. The concept could thus be implemented in materials for cartilage repair, whereby in situ recruited/infiltrated chondroprogenitor cells would proliferate while maintaining their ability to differentiate and generate cartilage tissue.

Biofilms and their extracellular environment on geomaterials: methods for investigation down to nanometre scale

On solid surfaces of building material, micro-organisms form a tightly attached layer that may affect the underlying substratum. The biofilm is mainly composed of cells and extracellular polymeric substances (EPS; mostly various polysaccharides). Attachment of the mature biofilm on the substratum is mediated by the EPS. For analysis by transmission electron microscopy, the biofilm structure must be maintained by appropriate methods that stabilize the organisms and especially the EPS. Specially adapted preparation techniques allow detachment of a surface biofilm or dissolution of the substratum without affecting the biofilm structure. The cellular and extracellular structures are retained in such a way that they are detectable by various specific marker systems.