Protein kinase A activity modulates natriuretic peptide-dependent cGMP accumulation in renal cells.
The purpose of this work was to examine whether the level of cAMP accumulation and protein kinase A (PKA) activity influence atrial natriuretic factor (ANF)-dependent guanosine 3',5'-cyclic monophosphate (cGMP) production in two renal cell types: rabbit cortical vascular smooth muscle cells (RCSMC) and SV-40-transformed human glomerular visceral epithelial cells (HGVEC-SV1). N-[2-(p-bromocinnamylamino)ethyl]- 5-isoquinolinesulfonamide (H-89), a PKA inhibitor, decreased ANF-stimulated cGMP production in RCSMC in a time- and concentration-dependent manner. ANF-stimulated cGMP production was markedly inhibited after prolonged 9- and 18-h incubations with 25 microM H-89 (52 and 65%, respectively) but was not altered after exposure of cells to this agent for 1 h. 1-(5-Isoquinolinylsulfonyl)-2-methylpiperazine and N-(2-[methylamino]ethyl)-5-isoquinolinesulfonamide, protein kinase inhibitors not selective for PKA, did not reproduce the effect of H-89, even at higher concentrations (50 and 100 microM). Cycloheximide (10 microM), a protein synthesis inhibitor, limited the inhibitory effect of H-89, although alone it did not modify the ANF-stimulated cGMP production. H-89 did not affect cGMP production when it was stimulated by SIN-1, a nitric oxide donor. Prolonged incubation (18 h) with 8-bromo cAMP or cholera toxin, an activator of Gs protein resulting in adenylate cyclase stimulation, enhanced ANF-dependent cGMP production by 225 and 176%, respectively. This stimulatory effect was blocked by 25 microM H-89. 125I-ANF binding to RCSMC at 4 degrees C was not affected by preincubation of the cells with H-89. There was a 44% decrease in the expression of ANF C receptors measured as the ANF-(4-23)-displaceable 125I-ANF binding at 37 degrees C, which could not, however, explain the inhibitory effect of H-89 on cGMP production. Modulation of ANF- and C-type natriuretic peptide-dependent cGMP production by H-89 and cholera toxin was also found in HGVEC-SV1 with the same characteristics as in RCSMC. Taken together, these results suggest that PKA activity controls the function of natriuretic peptide guanylate cyclase-coupled receptors in the two cell types studied. PKA-dependent inhibition of a negatively regulatory protein distinct from the receptor itself seems necessary for a full cGMP response.
Ledoux
S
S
Institut National de la Santé et de la Recherche Médicale 64, Hôpital Tenon, Paris, France.
Dussaule
J C
JC
Chatziantoniou
C
C
Ardaillou
N
N
Vandermeersch
S
S
Ardaillou
R
R
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism / Q000502:physiology*; D002478:Cells, Cultured; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D007672:Kidney Cortex / Q000098:blood supply; D007678:Kidney Glomerulus / Q000166:cytology / Q000378:metabolism; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism; D011817:Rabbits
D009320:Atrial Natriuretic Factor; D017868:Cyclic AMP-Dependent Protein Kinases; D006152:Cyclic GMP