Ca(2+) signalling and PKCalpha activate increased endothelial permeability by disassembly of VE-cadherin junctions
| Autor: | Sandoval, R., Malik, A. B., Minshall, R. D., Kouklis, P., Ellis, C. A., Tiruppathi, C. |
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| Jazyk: | angličtina |
| Rok vydání: | 2001 |
| Předmět: |
Calcium/metabolism
Protein Kinase C-alpha Endothelium Vascular/cytology Umbilical Veins/cytology Cadherins/*metabolism Antigens CD Electric Impedance Cell Membrane Permeability/drug effects/physiology Humans Thapsigargin/pharmacology Isoenzymes/*metabolism Cells Cultured Stress Fibers/physiology Enzyme Inhibitors/pharmacology Cytoskeletal Proteins/metabolism Iodine Radioisotopes/diagnostic use Tetradecanoylphorbol Acetate/pharmacology Hemostatics/pharmacology Calcium Signaling/drug effects/*physiology Carcinogens/pharmacology Desmoplakins Intercellular Junctions/*enzymology Myosin Light Chains/metabolism Thrombin/pharmacology Protein Kinase C/*metabolism Albumins/pharmacokinetics Naphthalenes/pharmacology |
| Popis: | 1. The role of intracellular Ca(2+) mobilization in the mechanism of increased endothelial permeability was studied. Human umbilical vein endothelial cells (HUVECs) were exposed to thapsigargin or thrombin at concentrations that resulted in similar increases in intracellular Ca(2+) concentration ([Ca(2+)](i)). The rise in [Ca(2+)](i) in both cases was due to release of Ca(2+) from intracellular stores and influx of extracellular Ca(2+). 2. Both agents decreased endothelial cell monolayer electrical resistance (a measure of endothelial cell shape change) and increased transendothelial (125)I-albumin permeability. Thapsigargin induced activation of PKCalpha and discontinuities in VE-cadherin junctions without formation of actin stress fibres. Thrombin also induced PKCalpha activation and similar alterations in VE-cadherin junctions, but in association with actin stress fibre formation. 3. Thapsigargin failed to promote phosphorylation of the 20 kDa myosin light chain (MLC(20)), whereas thrombin induced MLC(20) phosphorylation consistent with formation of actin stress fibres. 4. Calphostin C pretreatment prevented the disruption of VE-cadherin junctions and the decrease in transendothelial electrical resistance caused by both agents. Thus, the increased [Ca(2+)](i) elicited by thapsigargin and thrombin may activate a calphostin C-sensitive PKC pathway that signals VE-cadherin junctional disassembly and increased endothelial permeability. 5. Results suggest a critical role for Ca(2+) signalling and activation of PKCalpha in mediating the disruption of VE-cadherin junctions, and thereby in the mechanism of increased endothelial permeability. J Physiol |
| Databáze: | OpenAIRE |
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