The maintenance of pancreatic islet architecture is crucial for proper beta-cell function. We previously reported that disruption of human islet integrity could result in altered beta-cell identity... Show moreThe maintenance of pancreatic islet architecture is crucial for proper beta-cell function. We previously reported that disruption of human islet integrity could result in altered beta-cell identity. Here we combine beta-cell lineage tracing and single-cell transcriptomics to investigate the mechanisms underlying this process in primary human islet cells. Using drug-induced ER stress and cytoskeleton modification models, we demonstrate that altering the islet structure triggers an unfolding protein response that causes the downregulation of beta-cell maturity genes. Collectively, our findings illustrate the close relationship between endoplasmic reticulum homeostasis and beta-cell phenotype, and strengthen the concept of altered beta-cell identity as a mechanism underlying the loss of functional beta-cell mass. Show less
Groen, N.; Leenders, F.; Mahfouz, A.; Munoz-Garcia, A.; Muraro, M.J.; Graaf, N. de; ... ; Carlotti, F. 2021
The maintenance of pancreatic islet architecture is crucial for proper β-cell function. We previously reported that disruption of human islet integrity could result in altered β-cell identity. Here... Show moreThe maintenance of pancreatic islet architecture is crucial for proper β-cell function. We previously reported that disruption of human islet integrity could result in altered β-cell identity. Here we combine β-cell lineage tracing and single-cell transcriptomics to investigate the mechanisms underlying this process in primary human islet cells. Using drug-induced ER stress and cytoskeleton modification models, we demonstrate that altering the islet structure triggers an unfolding protein response that causes the downregulation of β-cell maturity genes. Collectively, our findings illustrate the close relationship between endoplasmic reticulum homeostasis and β-cell phenotype, and strengthen the concept of altered β-cell identity as a mechanism underlying the loss of functional β-cell mass. Show less
Melsen, J.; Themeli, M.; Ostaijen-ten Dam, M. van; Beelen, E. van; Lugthart, G.; Hoeben, R.; ... ; Mikkers, H. 2020
Natural killer (NK) cells are innate immune cells, characterized by their cytotoxic capacity, and chemokine and cytokine secretion upon activation. Human NK cells are identified by CD56 expression.... Show moreNatural killer (NK) cells are innate immune cells, characterized by their cytotoxic capacity, and chemokine and cytokine secretion upon activation. Human NK cells are identified by CD56 expression. Circulating NK cells can be further subdivided into the CD56(bright) (similar to 10%) and CD56(dim) NK cell subsets (similar to 90%). NK cell-like cells can also be derived from human induced pluripotent stem cells (iPSC). To study the chemokine and cytokine secretion profile of the distinct heterogenous NK cell subsets, intracellular flow cytometry staining can be performed. However, this assay is challenging when the starting material is limited. Alternatively, NK cell subsets can be enriched, sorted, stimulated, and functionally profiled by measuring secreted effector molecules in the supernatant by Luminex Here, we provide a rapid and straightforward protocol for the isolation and stimulation of primary NK cells or iPSC-derived NK cell-like cells, and subsequent detection of secreted cytokines and chemokines, which is also applicable for a low number of cells. Show less
Mezzanotte, L.; Iljas, J.D.; Que, I.; Chan, A.; Kaijzel, E.; Hoeben, R.; Lowik, C. 2017
