RT Journal Article
SR Electronic
T1 Basic Fibroblast Growth Factor Activates Endothelial Nitric-Oxide Synthase in CHO-K1 Cells via the Activation of Ceramide Synthesis
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 297
OP 310
DO 10.1124/mol.63.2.297
VO 63
IS 2
A1 Tullio Florio
A1 Sara Arena
A1 Alessandra Pattarozzi
A1 Stefano Thellung
A1 Alessandro Corsaro
A1 Valentina Villa
A1 Alessandro Massa
A1 Fabrizio Diana
A1 Giuseppe Spoto
A1 Sabrina Forcella
A1 Gianluca Damonte
A1 Mirella Filocamo
A1 Umberto Benatti
A1 Gennaro Schettini
YR 2003
UL http://molpharm.aspetjournals.org/content/63/2/297.abstract
AB In this study, we analyzed the intracellular mechanisms leading to basic fibroblast growth factor (bFGF)-dependent production of NO in Chinese hamster ovary (CHO)-K1 cells and a possible physiological role for such an effect. bFGF induces NO production through the activation of the endothelial form of NO synthase (eNOS), causing a subsequent increase in the cGMP levels. In these cells, the activation of eNOS by bFGF is Ca2+- and mitogen-activated protein kinase-independent. The translocation of the enzyme from the plasma membrane, where it is located in caveolae bound to caveolin 1, to the cytosol is the crucial step for the synthesis of NO through the eNOS isoform. We demonstrate that bFGF activates a sphingomyelinase to synthesize ceramide, which, in turn, allows the dissociation of eNOS from caveolin 1 and its translocation to the cytosol in the active form, where it catalyzes the synthesis of NO. In fact, drugs interfering with sphingomyelinase activity blocked bFGF activation of eNOS, and an increase in ceramide content was detected after bFGF treatment. Moreover, in fibroblasts derived from patients with Niemann-Pick disease, in which the enzyme is genetically inactive, bFGF is unable to elicit eNOS activation. The NO produced after bFGF treatment, through the activation of guanylyl cyclase and protein kinase G, mediates a mitogen-activated protein kinase-independent cell proliferation. In conclusion, our data show that, in CHO-K1 cells, bFGF regulates the activity of eNOS through a novel intracellular pathway, involving the induction of ceramide synthesis and that the NO released participates in bFGF proliferative activity. The American Society for Pharmacology and Experimental Therapeutics