Characterization of dual agonists for kinin B1 and B2 receptors and their biased activation of B2 receptors

Xianming Zhang,Jessica L Lowry,Viktor Brovkovych,Randal A Skidgel

doi:10.1016/j.cellsig.2012.04.002

Xianming Zhang, Jessica L Lowry + Show 2 more

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https://doi.org/10.1016/j.cellsig.2012.04.002

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Journal: Cellular Signalling	Publication Date: Apr 12, 2012
Citations: 9	License type: cc-by

Affiliation: University of Illinois at Chicago

Abstract

Kinin B1 and B2 receptors (kB1R and kB2R) play important roles in many physiological and pathological processes. In some cases, kB1R or kB2R activation can have overlapping or complementary beneficial effects, thus an activator of both receptors might be advantageous. We found that replacement of the C-terminal Arg in the natural kB2R activators bradykinin (BK) or kallidin (KD) with Lys (K9-BK or K10-KD) resulted in agonists that effectively stimulate the downstream signaling of both the kB1R and kB2R as measured by increased inositol turnover, intracellular calcium, ERK1/2 phosphorylation, arachidonic acid release and NO production. However, K9-BK and K10-KD displayed some characteristics of biased agonism for kB2Rs as indicated by the rapid kinetics of ERK1/2 phosphorylation induced by K9-BK or K10-KD compared with the prolonged response mediated by BK or KD. In contrast, kinetics of ERK phosphorylation stimulated by K10-KD activation of the kB1R was the same as that induced by known kB1R agonist des-Arg10-KD. Furthermore, the endocytosis of kB2Rs mediated by K9-BK and K10-KD was remarkably less than that induced by BK and KD respectively. K10-KD stimulated kB1R and kB2R-dependent calcium responses and ERK1/2 phosphorylation in bovine endothelial cells. In cytokine-treated human endothelial cells, K10-KD stimulated ERK1/2 phosphorylation and a transient peak of NO production that was primarily kB2R-dependent. K10-KD also stimulated prolonged NO production that was both kB1R and kB2R-dependent. These data provide the first examples of dual agonists of kB1R and kB2R, and a biased agonist of kB2R and may provide useful clues for developing dual modulators of kB1Rs and kB2Rs for potential therapeutic use.

Highlights

Bradykinin (BK) or kallidin (KD) are 9 or 10 amino acid peptides released kininogen precursors by plasma or tissue kallikrein that selectively activate the kinin B2 receptor [1, 2]
KB1R and kinin B2 receptor (kB2R) activation can have deleterious effects, causing pain and inflammation. Both kinin B1 receptor (kB1R) and kB2R are involved in nociception as kB2R agonist BK induced thermal hyperalgesia in kB1R knockout mice and kB1R agonist DABK induced the thermal hyperalgesia in kB2R knockout mice [17]. kB1R regulates pain by facilitating the nociceptive spinal reflex, as it was decreased in kB1R knockout mice [18]
Because cell environment and receptor overexpression can have significant effects on receptor activation and signaling, we tested the ability of K9-BK and K10-KD to stimulate responses in Bovine pulmonary artery endothelial cells (BPAEC), one of the few cell types that constitutively express both receptors [3, 44, 45]. Both K9-BK and K10-KD (1 μM) stimulated a large increase in [Ca2+]i that was partially blocked by either kB2R antagonist HOE140 or kB1R antagonist DALKD and completely blocked by a combination of both antagonists. We found that both K9-BK and K10-KD stimulated ERK1/2 phosphorylation in BPAEC that were pretreated with either kB1R antagonist DALKD or kB2R antagonist HOE140 that was inhibited by a combination of both antagonists (Fig. 12)

Summary

Introduction

Bradykinin (BK) or kallidin (KD) are 9 or 10 amino acid peptides released kininogen precursors by plasma or tissue kallikrein that selectively activate the kinin B2 receptor (kB2R) [1, 2]. Diabetic nephropathy was markedly enhanced in kB2R knockout mice [15] and renal injury due to ischemia/reperfusion was markedly worse in kB1R and kB2R double knockout mice compared with kB2R knockout or wild type mice [16]. These data indicate beneficial roles for kB1R and kB2R signaling in the cardiovascular and renal systems. KB1R and kB2R activation can have deleterious effects, causing pain and inflammation Both kB1R and kB2R are involved in nociception as kB2R agonist BK induced thermal hyperalgesia in kB1R knockout mice and kB1R agonist DABK induced the thermal hyperalgesia in kB2R knockout mice [17]. In experimental autoimmune encephalomyelitis, leukocytes infiltrating into the central nervous system were decreased in kB2R knockout mice whereas T helper type 17 cells were reduced in kB1R knockout mice [19, 20]

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