Subcellular analysis of blood-brain barrier function by micro-impalement of vessels in acute brain slices.

The blood-brain barrier (BBB) is a tightly and actively regulated vascular barrier. Answering fundamental biological and translational questions about the BBB with currently available approaches is hampered by a trade-off between accessibility and biological validity. We report an approach combining micropipette-based local perfusion of capillaries in acute brain slices with multiphoton microscopy.

Optical analysis of glutamate spread in the neuropil.

Fast synaptic communication uses diffusible transmitters whose spread is limited by uptake mechanisms. However, on the submicron-scale, the distance between two synapses, the extent of glutamate spread has so far remained difficult to measure. Here, we show that quantal glutamate release from individual hippocampal synapses activates extracellular iGluSnFr molecules at a distance of >1.

Cell biologists sort things out: Analysis and purification of intracellular organelles by flow cytometry.

Flow cytometry was established originally for measuring DNA content and for the analysis of cell-surface markers in combination with cell sorting. During the past two decades, it has added new dimensions to various areas of immunology and medicine. Increased sensitivity and precision of flow cytometers, accompanied by the development of new fluorescent dyes and probes, has led to new applications in molecular cell biology and genetics.

Differential regulation of Foxo3a target genes in erythropoiesis.

The cooperation of stem cell factor (SCF) and erythropoietin (Epo) is required to induce renewal divisions in erythroid progenitors, whereas differentiation to mature erythrocytes requires the presence of Epo only. Epo and SCF activate common signaling pathways such as the activation of protein kinase B (PKB) and the subsequent phosphorylation and inactivation of Foxo3a. In contrast, only Epo activates Stat5.

TGF-beta-induced apoptosis in endothelial cells mediated by M6P/IGFII-R and mini-plasminogen.

Transforming growth factor-beta (TGF-beta), a key modulator of endothelial cell apoptosis, must be activated from the latent form (LTGF-beta) to induce biological responses. In the present study, we report activation of TGF-beta by functional and physical co-operation of the mannose-6-phosphate/insulin-like-growth-factor-II receptor (CD222) and the urokinase-type plasminogen activator receptor (CD87). We show that endothelial cells express CD222 and CD87 in a membrane complex and demonstrate that the association of these two receptors is essential for the release of active TGF-beta in the transduced mouse fibroblast used as model cells.