SummaryThe human intestinal mucosa is a critical site for absorption, distribution, metabolism, and excretion (ADME)/Tox studies in drug development and is difficult to recapitulate in vitro. Using bioprinting, we generated three-dimensional (3D) intestinal tissue composed of human primary intestinal epithelial cells and myofibroblasts with architecture and function to model the native intestine. The 3D intestinal tissue demonstrates a polarized epithelium with tight junctions and specialized epithelial cell types and expresses functional and inducible CYP450 enzymes. The 3D intestinal tissues develop physiological barrier function, distinguish between high- and low-permeability compounds, and have functional P-gp and BCRP transporters. Biochemical and histological characterization demonstrate that 3D intestinal tissues can generate an injury response to compound-induced toxicity and inflammation. This model is compatible with existing preclinical assays and may be implemented as an additional bridge to clinical trials by enhancing safety and efficacy prediction in drug development.

The authors have characterized a set of cannabinoid CB 2 receptor ligands, including triaryl bis sulfone inverse agonists, in a cell-based receptor/β-arrestin interaction assay (DiscoveRx PathHunter ™ ). The results were compared with results using a competitive ligand binding assay, and with effects on forskolin-stimulated cAMP levels (PerkinElmer LANCE ™ ). The authors show good correlation between the 3 assay systems tested, with the β-arrestin protein complementation assay exhibiting a more robust signal than the cAMP assay for cannabinoid CB 2 agonists. Further assay validation shows that DiscoveRx PathHunter ™ HEK293 CB 2 β-arrestin assay can be carried out from cryopreserved cell suspensions, eliminating variations caused by the need for multiple cell pools during live cell screening campaigns. These results, and the authors' results evaluating a test set of random library compounds, validate the use of ligand-induced interaction between the human cannabinoid CB 2 receptor and β-arrestin as an appropriate and valuable screening platform for compounds specific for the cannabinoid CB 2 receptor. (Journal of Biomolecular Screening 2009:49-58)

A new subseries of ROMK inhibitors exemplified by 28 has been developed from the initial screening hit 1. The excellent selectivity for ROMK inhibition over related ion channels and pharmacokinetic properties across preclinical species support further preclinical evaluation of 28 as a new mechanism diuretic. Robust pharmacodynamic effects in both SD rats and dogs have been demonstrated.

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Human myeloma bone disease (MBD) occurs when malignant plasma cells migrate to the bone marrow and commence inimical interactions with stromal cells, disrupting the skeletal remodeling process. The myeloma cells simultaneously suppress osteoblastic bone formation while promoting excessive osteoclastic resorption. This bone metabolism imbalance produces osteolytic lesions that cause chronic bone pain and reduce trabecular and cortical bone structural integrity, and often culminate in pathological fractures. Few bone models exist that enable scientists to study MBD and the effect therapies have on restoring the bone metabolism imbalance. The purpose of this research was to develop a well characterized three‐dimensional (3D) bone organoid that could be used to study MBD and current or potential treatment options. First, bone marrow stromal cell–derived osteoblasts (OBs) mineralized an endosteal‐like extracellular matrix (ECM) over 21 days. Multiple analyses confirmed the generation of hydroxyapatite (HA)‐rich bone‐like tissue fragments that were abundant in alkaline phosphatase, calcium, and markers of osteoblastic gene expression. On day 22, bone marrow macrophage (BMM)–derived osteoclasts (OCs) were introduced to enhance the resorptive capability of the model and recapitulate the balanced homeostatic nature of skeletal remodeling. Tartrate‐resistant acid phosphatase 5b (TRAcP‐5b), type I collagen C‐telopeptide (CTX‐1), and gene expression analysis confirmed OC activity in the normal 3D organoid (3D in vitro model of normal bonelike fragments [3D‐NBF]). On day 30, a human multiple myeloma (MM)–derived plasmacytoma cell line was introduced to the 3D‐NBF to generate the 3D‐myeloma bone disease organoid (3D‐MBD). After 12 days, the 3D‐MBD had significantly reduced total HA, increased TRAcP‐5b levels, increases levels of CTX‐1, and decreased expression of osteoblastic genes. Therapeutic intervention with pharmaceutical agents including an immunomodulatory drug, a bisphosphonate, and monoclonal restored HA content and reduced free CTX‐1 in a dose‐dependent manner. This osteogenically functional model of MBD provides a novel tool to study biological mechanisms guiding the disease and to screen potential therapeutics. © 2021 American Society for Bone and Mineral Research (ASBMR).