ET-1- and NO-mediated signal transduction pathway in human brain capillary endothelial cells.
Previous studies have demonstrated that functional interaction between endothelin (ET)-1 and nitric oxide (NO) involves changes in Ca(2+) mobilization and cytoskeleton in human brain microvascular endothelial cells. The focus of this investigation was to examine the possible existence of analogous interplay between these vasoactive substances and elucidate their signal transduction pathways in human brain capillary endothelial cells. The results indicate that ET-1-stimulated Ca(2+) mobilization in these cells is dose-dependently inhibited by NOR-1 (an NO donor). This inhibition was prevented by ODQ (an inhibitor of guanylyl cyclase) or Rp-8-CPT-cGMPS (an inhibitor of protein kinase G). Treatment of endothelial cells with 8-bromo-cGMP reduced ET-1-induced Ca(2+) mobilization in a manner similar to that observed with NOR-1 treatment. In addition, NOR-1 or cGMP reduced Ca(2+) mobilization induced by mastoparan (an activator of G protein), inositol 1,4,5-trisphosphate, or thapsigargin (an inhibitor of Ca(2+)-ATPase). Interestingly, alterations in endothelial cytoskeleton (actin and vimentin) were associated with these effects. The data indicate for the first time that the cGMP-dependent protein kinase colocalizes with actin. These changes were accompanied by altered levels of phosphorylated vasodilator-stimulated phosphoprotein, which were elevated in endothelial cells incubated with NOR-1 and significantly reduced by ODQ or Rp-8-CPT-cGMPS. The findings indicate a potential mechanism by which the functional interrelationship between ET-1 and NO plays a role in regulating capillary tone, microcirculation, and blood-brain barrier function.
Chen
Y
Y
Stroke Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda 20892, USA.
McCarron
R M
RM
Golech
S
S
Bembry
J
J
Ford
B
B
Lenz
F A
FA
Azzam
N
N
Spatz
M
M
D000199:Actins / Q000187:drug effects / Q000378:metabolism; D001120:Arginine / Q000494:pharmacology; D001921:Brain / Q000098:blood supply* / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D002560:Cerebrovascular Circulation / Q000502:physiology*; D017869:Cyclic GMP-Dependent Protein Kinases / Q000187:drug effects / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1 / Q000378:metabolism* / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007150:Immunohistochemistry; D008840:Microfilament Proteins; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010750:Phosphoproteins / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D044022:Receptor, Endothelin A; D017466:Receptors, Endothelin / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D000098662:Vasodilator-Stimulated Phosphoprotein
D000199:Actins; D015815:Cell Adhesion Molecules; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D004791:Enzyme Inhibitors; D008840:Microfilament Proteins; D020030:Nitric Oxide Donors; D010750:Phosphoproteins; D044022:Receptor, Endothelin A; D017466:Receptors, Endothelin; D000098662:Vasodilator-Stimulated Phosphoprotein; D009569:Nitric Oxide; D001120:Arginine; D017869:Cyclic GMP-Dependent Protein Kinases