The models account for the geometry of MPs and heterogeneous distribution of membrane channels and receptors in an EC. center dot Simulations show that SMC stimulation causes calcium release in and around EC MPs that activates hyperpolarizing currents in ECs and moderates SMC constriction. center dot The results help us better understand the mechanisms that regulate selleck kinase inhibitor blood flow and pressure. Abstract We investigated the role of myoendothelial projections (MPs) in endothelial cell (EC) feedback response to smooth muscle cell (SMC) stimulation using mathematical modelling. A previously developed compartmental
EC-SMC model is modified to include MPs as subcellular compartments in the EC. The model is further extended into a 2D continuum model using a finite element method (FEM) approach and electron microscopy images to account for MP geometry. The EC and SMC are coupled via non-selective myoendothelial gap junctions (MEGJs) which are located on MPs and allow exchange of Ca2+, K+, Na+ and Cl- ions and inositol 1,4,5-triphosphate (IP3). Models take into consideration recent evidence for co-localization of intermediate-conductance calcium-activated potassium channels (IKCa) and IP3 receptors (IP3Rs) in the MPs. SMC stimulation
causes an IP3-mediated Ca2+ transient in the MPs with limited global spread in the bulk EC. A hyperpolarizing feedback generated by the localized IKCa channels is transmitted to the SMC via MEGJs. MEGJ resistance (Rgj) and the density of IKCa and IP3R in the projection influence the extent of EC response to SMC stimulation. Momelotinib cell line The predicted Ca2+ transients depend also on the volume and geometry of the MP. We conclude that in the myoendothelial feedback response to SMC stimulation, GSK1120212 research buy MPs are required to amplify the SMC initiated signal. Simulations suggest that the signal is mediated by IP3 rather
than Ca2+ diffusion and that a localized rather than a global EC Ca2+ mobilization is more likely following SMC stimulation.”
“Vascular tumor is an abnormal buildup of blood vessels in the skin or internal organs that can lead to disfigurement and/or life-threatening consequences. The mechanism of hemangiogenesis remains unknown. The aim of this study was to assess the role of rapamycin-insensitive companion of mTOR (Rictor) in control of vascular tumor malignant biological behavior and cell signaling mechanism in Mouse Hemangioendothelioma Endothelial Cells (EOMA cells) and nude mouse model. Knocking down rictor was mediated by lentivirus shRNA. The role and mechanism of rictor in vascular tumor were assessed by western blotting, wst-1 proliferation assay, matrigel invasion assay and xenograft vascular tumor growth. Our results in vitro showed that loss of rictor down-regulated phosphorylation of AKT and S6 by which EOMA cells growth and proliferation were greatly suppressed. Knock down of rictor also inhibited the invasion of EOMA cells.