Neuropeptide Y receptor mediates activation of ERK1/2 via transactivation of the IGF receptor

Abstract

Neuropeptide Y binds to G-protein coupled receptors whose action results in inhibition of adenylyl cyclase activity. Using HEK293 cells stably expressing the native neuropeptide Y Y1 receptors, we found that the NPY agonist elicits a transient phosphorylation of the extracellular signal-regulated kinases (ERK1/2). We first show that ERK1/2 activation following Y1 receptor stimulation is dependent on heterotrimeric Gi/o since it is completely inhibited by pre-treatment with pertussis toxin. In addition, ERK1/2 activation is internalization-independent since mutant Y1 receptors unable to recruit β-arrestins, can still activate ERK signaling to the same extent as wild-type receptors. We next show that this activation of the MAPK pathway is inhibited by the MEK inhibitor U0126, is not dependent on calcium signaling at the Y1 receptor (no effect upon inhibition of phospholipase C, protein kinase C or protein kinase D) but instead dependent on Gβ/γ and associated signaling pathways that activate PI3-kinase. Although inhibition of the epidermal-growth factor receptor tyrosine kinase did not influence NPY-induced ERK1/2 activation, we show that the inhibition of insulin growth factor receptor IGFR by AG1024 completely blocks activation of ERK1/2 by the Y1 receptor. This Gβ/γ-PI3K-AG1024-sensitive pathway does not involve activation of IGFR through the release of a soluble ligand by metalloproteinases since it is not affected by the metalloproteinase inhibitor marimastat. Finally, we found that a similar pathway, sensitive to wortmannin-AG1024 but insensitive to marimastat, is implicated in activation of ERK signaling in HEK293 cells by endogenously expressed GPCRs coupled to Gq-protein (muscarinic M3 receptors) or coupled to Gs-protein (endothelin ETB receptors). Our analysis is the first to show that β-arrestin recruitment to the NPY Y1 receptor is not necessary for MAPK activation by this receptor but that transactivation of the IGFR receptor is required.

Neuropeptide Y1 Receptor Regulates Glucocorticoid-Induced Inhibition of Osteoblast Differentiation in Murine MC3T3-E1 Cells via ERK Signaling

“…ERK signaling promoted the mitogenic reaction of osteoblastic cells [28], and glucocorticoid was known to inhibit osteogenic differentiation through inactivation of ERK signaling osteoblasts [29]. Moreover, ERK signaling was reported to mediate the mitogenic reaction of NPY in non-osteoblastic cells [30,31], and the Y1 receptor regulated the activation of ERK signaling in HEK293 cells [32], suggesting a regulatory role of Y1 receptor in ERK signaling. In this study, treatment with Dex or Y1 receptor agonist inactivated ERK signaling, while blockade of Y1 receptor attenuates Dex-induced inactivation of ERK signaling.…”

The Role of Neuropeptide Y in Cardiovascular Health and Disease

“…The Y1R can also couple to mobilization of intracellular Ca 2+ stores depending on the cell type (Aakerlund et al, 1990 ; Herzog et al, 1992 ) via a G q -phospholipase C (PLC) dependent pathway (Del Puy Heredia et al, 2005 ). The IP 3 dependent mobilization of intracellular Ca 2+ can have a positive inotropic or vasoconstrictive effect, provoke contractile sensitisation, neurological functions such as learning and memory, immune regulation, lipid metabolism, and transcriptional regulation via the Ca 2+ -binding messenger calmodulin (CaM) (Troke et al, 2013 ; Lecat et al, 2015 ). The multi-functional effect of the Ca 2+ /CaM complex may be induced by the activation of CaM kinases such as Ca 2+ /CaM-dependent protein kinase II (CaMKII) and myosin light chain kinase (MLCK) (Leonard et al, 1999 ; Anderson, 2005 ).…”

G Protein–Coupled Receptor Signaling Through β-Arrestin–Dependent Mechanisms

“…25,29,86 β-arrestin2 inhibits EGFR transactivation by CXCR7 and counteracts mitogenic signaling and cell proliferation. 87 On the other hand, β-arrestins promote sphingosine-1-phosphate-induced transactivation of Fetal Liver Kinase 1 (Flk-1) through S1P1/S1P3 receptors, resulting in mouse embryonic stem cell proliferation.…”