RESUMEN
Bis-choline-tetrathiomolybdate, introduced as WTX101 (now known as ALXN1840), is a first-in-class copper-protein-binding agent for oral therapy of Wilson's disease. In contrast to other decoppering agents such as trientine or D-penicillamine it acts by forming a tripartite complex with copper and albumin, thereby detoxifying excess liver and blood copper through biliary excretion. Preclinical animal experimentation with this drug was typically done with the alternative ammonium salt of tetrathiomolybdate, which is expected to have identical properties in terms of copper binding. Here, we comparatively analyzed the therapeutic efficacy of ALXN1840, D-penicillamine and trientine in lowering hepatic copper content in Atp7b-/- mouse. Liver specimens were subjected to laser ablation inductively conductively plasma mass spectrometry and electron microscopic analysis. We found that ALXN1840 caused a massive increase of hepatic copper and molybdenum during early stages of therapy. Prolonged treatment with ALXN1840 reduced hepatic copper to an extent that was similar to that observed after administration of D-penicillamine and trientine. Electron microscopic analysis showed a significant increase of lysosomal electron-dense particles in the liver confirming the proposed excretory pathway of ALXN1840. Ultrastructural analysis of mice treated with dosages comparable to the bis-choline-tetrathiomolybdate dosage used in an ongoing phase III trial in Wilson's disease patients, as well as D-penicillamine and trientine, did not show relevant mitochondrial damage. In contrast, a high dose of ALXN1840 applied for four weeks triggered dramatic structural changes in mitochondria, which were notably characterized by the formation of holes with variable sizes. Although these experimental results may not be applicable to patients with Wilson's disease, the data suggests that ALXN1840 should be administered at low concentrations to prevent mitochondrial dysfunction and overload of hepatic excretory pathways.
RESUMEN
In vitro differentiation of airway epithelium is of interest for respiratory tissue engineering and studying airway diseases. Both applications benefit from the use of primary cells to maintain a mucociliated phenotype and thus physiological functionality. Complex differentiation procedures often lack standardization and reproducibility. To alleviate these shortfalls, we compared differentiation behavior of human nasal epithelial cells in four differentiation media. Cells were differentiated at the air-liquid interface (ALI) on collagen-coated inserts. Mucociliary differentiation status after five weeks was analyzed by electron microscopy, histology and immunohistochemistry. The amount of ciliation was estimated and growth factor concentrations were evaluated using ELISA. We found that retinoic-acid-supplemented mixture of DMEM and Airway Epithelial Cell Growth Medium gave most promising results to obtain ciliated and mucus producing nasal epithelium in vitro. We discovered the balance between retinoic acid (RA), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and fibroblast growth factor ß (FGF-ß) to be relevant for differentiation. We could show that low VEGF, EGF and FGF-ß concentrations in medium correspond to absent ciliation in specific donors. Therefore, our results may in future facilitate donor selection and non-invasive monitoring of ALI cultures and by this contribute to improved standardization of epithelial in vitro culture.