Kininase I-type carboxypeptidases enhance nitric oxide production in endothelial cells by generating bradykinin B1 receptor agonists.
Kininase I-type carboxypeptidases convert native kinin agonists for B(2) receptors into B(1) receptor agonists by specifically removing the COOH-terminal Arg residue. The membrane localization of carboxypeptidase M (CPM) and carboxypeptidase D (CPD) make them ideally situated to regulate kinin activity. Nitric oxide (NO) release from human lung microvascular endothelial cells (HLMVEC) was measured directly in real time with a porphyrinic microsensor. Bradykinin (1-100 nM) elicited a transient (5 min) peak of generation of NO that was blocked by the B(2) antagonist HOE 140, whereas B(1) agonist des-Arg(10)-kallidin caused a small linear increase in NO over 20 min. Treatment of HLMVEC with 5 ng/ml interleukin-1beta and 200 U/ml interferon-gamma for 16 h upregulated B(1) receptors as shown by an approximately fourfold increase in prolonged (>20 min) output of NO in response to des-Arg(10)-kallidin, which was blocked by the B(1) antagonist des-Arg(10)-Leu(9)-kallidin. B(2) receptor agonists bradykinin or kallidin also generated prolonged NO production in treated HLMVEC, which was significantly reduced by either a B(1) antagonist or carboxypeptidase inhibitor, and completely abolished with a combination of B(1) and B(2) receptor antagonists. Furthermore, CPM and CPD activities were increased about twofold in membrane fractions of HLMVEC treated with interleukin-1beta and interferon-gamma compared with control cells. Immunostaining localized CPD primarily in a perinuclear/Golgi region, whereas CPM was on the cell membrane. These data show that cellular kininase I-type carboxypeptidases can enhance kinin signaling and NO production by converting B(2) agonists to B(1) agonists, especially in inflammatory conditions.
Sangsree
Sakonwun
S
Department of Pharmacology, University of Illinois College of Medicine, Chicago 60612, USA.
Brovkovych
Viktor
V
Minshall
Richard D
RD
Skidgel
Randal A
RA
D001920:Bradykinin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002196:Capillaries / Q000378:metabolism; D002268:Carboxypeptidases / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D007609:Kallidin / Q000031:analogs & derivatives / Q000494:pharmacology; D001121:Lysine Carboxypeptidase / Q000494:pharmacology*; D009569:Nitric Oxide / Q000096:biosynthesis*; D011652:Pulmonary Circulation / Q000187:drug effects; D043783:Receptor, Bradykinin B1; D018002:Receptors, Bradykinin / Q000819:agonists*; D013268:Stimulation, Chemical; D013347:Subcellular Fractions / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects
D007375:Interleukin-1; D043783:Receptor, Bradykinin B1; D018002:Receptors, Bradykinin; D009569:Nitric Oxide; D007609:Kallidin; C065679:icatibant; D007371:Interferon-gamma; D002268:Carboxypeptidases; D001121:Lysine Carboxypeptidase; D001920:Bradykinin