Naslov
Interaction between bradykinin and natriuretic peptides via RGS protein activation in HEK-293 cells

Autori
Dobrivojević, Marina ; Sinđić, Aleksandra ; Edemir, Bayram ; Kalweit, Stefanie ; Forssmann, Wolf-Georg ; Hirsch, R. Jochen

Izvornik
American journal of physiology. Cell physiology (0363-6143) 303 (2012), 12; C1260-C1268

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
8-Br-cGMP; PKG; bradykinin type 2 receptor; signaling

Sažetak
In this study, the interaction of natriuretic peptides (NP) and bradykinin (BK) signaling pathways was identified by measuring membrane potential (Vm) and intracellular Ca2
using the patch-clamp technique and flow cytometry in HEK-293 cells. BK and NP receptor mRNA was identified using RT-PCR. BK (100 nM) depolarized cells activating bradykinin receptor type 2 (B2R) and Ca2
-dependent Cl channels inhibitable by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB ; 10 M). The BK-induced Ca2
signal was blocked by the B2R inhibitor HOE 140. [Des-Arg9]-bradykinin, an activator of B1R, had no effect on intracellular Ca2
. NP [atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and urodilatin] depolarized HEK-293 cells inhibiting K
channels. ANP, urodilatin, BNP [binding to natriuretic peptide receptor (NPR)-A] and 8-bromo- (8-Br)-cGMP inhibited the BK-induced depolarization while CNP (binding to NPR-Bi) failed to do so. The inhibitory effect on BKtriggered depolarization could be reversed by blocking PKG using the specific inhibitor KT 5823. BK-stimulated depolarization as well as Ca2
signaling was completely blocked by the phospholipase C (PLC) inhibitor U-73122 (10 nM). The inositol 1, 4, 5-trisphosphate receptor blocker 2-aminoethoxydiphenyl borate (2-APB ; 50 M) completely inhibited the BK-induced Ca2
signaling. UTP, another activator of the PLC-mediated Ca2
signaling pathway, was blocked by U-73122 as well but not by 8-Br-cGMP, indicating an intermediate regulatory step for NP via PKG in BK signaling such as regulators of G-protein signaling (RGS) proteins. When RGS proteins were inhibited by CCG-63802 in the presence of BK and 8-Br-cGMP, cells started to depolarize again. In conclusion, as natural antagonists of the B2R signaling pathway, NP may also positively interact in pathological conditions caused by BK.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

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