High-throughput 3D microvessel-on-a-chip model to study defective angiogenesis in systemic sclerosis.

In early systemic sclerosis (Scleroderma, SSc), the vasculature is impaired. Although the exact etiology of endothelial cell damage in SSc remains unclear, it is hypothesized that endothelial to mesenchymal transition (EndoMT) plays a key role. To perform physiologically relevant angiogenic studies, we set out to develop an angiogenesis-on-a-chip platform that is suitable for assessing disease parameters that are relevant to SSc and other vasculopathies.

A 3D Renal Proximal Tubule on Chip Model Phenocopies Lowe Syndrome and Dent II Disease Tubulopathy.

Lowe syndrome and Dent II disease are X-linked monogenetic diseases characterised by a renal reabsorption defect in the proximal tubules and caused by mutations in the OCRL gene, which codes for an inositol-5-phosphatase. The life expectancy of patients suffering from Lowe syndrome is largely reduced because of the development of chronic kidney disease and related complications. There is a need for physiological human in vitro models for Lowe syndrome/Dent II disease to study the underpinning disease mechanisms and to identify and characterise potential drugs and drug targets.

Development of a Gut-On-A-Chip Model for High Throughput Disease Modeling and Drug Discovery.

A common bottleneck in any drug development process is finding sufficiently accurate models that capture key aspects of disease development and progression. Conventional drug screening models often rely on simple 2D culture systems that fail to recapitulate the complexity of the organ situation. In this study, we show the application of a robust high throughput 3D gut-on-a-chip model for investigating hallmarks of inflammatory bowel disease (IBD).

Highly efficient gene inactivation by adenoviral CRISPR/Cas9 in human primary cells.

Phenotypic assays using human primary cells are highly valuable tools for target discovery and validation in drug discovery. Expression knockdown (KD) of such targets in these assays allows the investigation of their role in models of disease processes. Therefore, efficient and fast modes of protein KD in phenotypic assays are required.

Munc13-4*rab27 complex tethers secretory lysosomes at the plasma membrane.

Natural Killer (NK) cells and Cytotoxic T lymphocytes (CTL) are critical for the immune response against virus infections or transformed cells. They kill target cells via polarized exocytosis of lytic proteins from secretory lysosomes (SL). Rab27a and munc13-4 interact directly and are required for target cell killing.

A novel Dutch mutation in UNC13D reveals an essential role of the C2B domain in munc13-4 function.

Background: UNC13D, encoding the protein munc13-4, is essential in intracellular trafficking and exocytosis of lytic granules. Mutations in this gene are associated with familial hemophagocytic lymphohistiocytosis type 3 (FHL3), a genetically heterogeneous, rare autosomal recessive immune disorder. How mutations affect function of munc13-4 is poorly understood.

The munc13-4-rab27 complex is specifically required for tethering secretory lysosomes at the plasma membrane.

Cytotoxic T lymphocytes (CTLs) kill target cells through the polarized release of lytic molecules from secretory lysosomes. Loss of munc13-4 function inhibits this process and causes familial hemophagocytic lymphohistiocytosis type 3 (FHL3). munc13-4 binds rab27a, but the necessity of the complex remains enigmatic, because studies in knockout models suggest separate functions.

A platform for complementation and characterization of familial haemophagocytic lymphohistiocytosis 3 mutations.

Mutations in UNC13D cause the severe immune disorder familial haemophagocytic lymphohistiocytosis type 3 (FHL3). The gene product munc13-4 is expressed in hematopoietic cells and is essential for degranulation. Little information is available on genotype-phenotype relationships of UNC13D mutations.

Rab27a is required for human cytomegalovirus assembly.

Human cytomegalovirus (HCMV) completes its final envelopment on intracellular membranes before it is released from the cell. The mechanisms underlying these processes are not understood. Here we studied the role of Rab27a, a regulator of lysosome-related organelle transport, in HCMV production.

Methods for analysis of rab27a/Munc13-4 in secretory lysosome release in hematopoietic cells.

Secretory lysosomes constitute a heterogeneous organelle of hematopoietic cells that combines the properties of regular lysosomes with those of secretory granules. Although secretory lysosomes serve essential functions, such as in the immune system and blood clotting, the mechanisms underlying the release of contents are incompletely understood. It is clear, however, that rab27a and the C2 domain protein munc13-4 serve essential functions.