Adenylate cyclase 5 coordinates the action of ADP, P2Y1, P2Y13 and ATP-gated P2X7 receptors on axonal elongation

Abstract

SummaryIn adult brains, ionotropic or metabotropic purinergic receptors are widely expressed in neurons and glial cells. They play an essential role in inflammation and neurotransmission in response to purines secreted to the extracellular medium. Recent studies have demonstrated a role for purinergic receptors in proliferation and differentiation of neural stem cells although little is known about their role in regulating the initial neuronal development and axon elongation. The objective of our study was to investigate the role of some different types of purinergic receptors, P2Y1, P2Y13 and P2X7, which are activated by ADP or ATP. To study the role and crosstalk of P2Y1, P2Y13 and P2X7 purinergic receptors in axonal elongation, we treated neurons with specific agonists and antagonists, and we nucleofected neurons with expression or shRNA plasmids. ADP and P2Y1-GFP expression improved axonal elongation; conversely, P2Y13 and ATP-gated P2X7 receptors halted axonal elongation. Signaling through each of these receptor types was coordinated by adenylate cyclase 5. In neurons nucleofected with a cAMP FRET biosensor (ICUE3), addition of ADP or Blue Brilliant G, a P2X7 antagonist, increased cAMP levels in the distal region of the axon. Adenylate cyclase 5 inhibition or suppression impaired these cAMP increments. In conclusion, our results demonstrate a crosstalk between two metabotropic and one ionotropic purinergic receptor that regulates cAMP levels through adenylate cyclase 5 and modulates axonal elongation triggered by neurotropic factors and the PI3K-Akt-GSK3 pathway.

P2Y1 receptor mediated neuronal fibre outgrowth in organotypic brain slice co-cultures

“…Moreover, it is well known that the P2Y 1 R can control neuronal and glial functions. In addition to the already demonstrated direct role of the neuronal P2Y 1 R on axonal elongation (Del Puerto et al, 2012), we further suggest an indirect glial mediated mechanism. Our hypothesis is substantiated by our qualitative findings demonstrating an enhanced phosphorylation of Akt and ERK1/2 co-localised with GFAP-positive structures after ADPbSstimulation.…”

“…This particular subtype is also expressed in the distal region of axons and growth cones in primary cultures of embryonic hippocampal neurons. In this model, P2Y 1 R function was shown to be necessary for proper axonal growth (Del Puerto et al, 2012).…”

“…Del Puerto et al (2012) demonstrated a direct role of the neuronal P2Y 1 R on axonal elongation. ADP and P2Y 1 R-GFP expression improved axonal elongation in primary cultures of embryonic hippocampal neurons, but activation of the P2Y 13 R and P2X7R subtypes negatively modulated axon growth (Del Puerto et al, 2012).…”

“…The activation of both pathways by P2Y 1 R has for example been related to proliferation (Franke et al, 2009;Gerasimovskaya et al, 2005;Ornelas and Ventura, 2010;Van Kolen and Slegers, 2006), cell migration (Montiel et al, 2006;Shen and DiCorleto, 2008) and axonal growth (Del Puerto et al, 2013). Thus, the stimulation of the P2Y 1 R promoted axonal elongation via the activation of the PI3K-Akt-GSK3 pathway (Del Puerto et al, 2012). P2Y 1 R activation furthermore leads to the regulation of gene expression of distinct effectors of the synaptic transmission via the MAPK/Raf-1 signalling cascade (Siow et al, 2010).…”

The enteric nervous system of P2Y13 receptor null mice is resistant against high-fat-diet- and palmitic-acid-induced neuronal loss

“…It was initially identified in the spleen and brain but is also expressed in the dorsal root ganglia, microglia, pancreatic beta cells, hepatocytes and mast cells [10][11][12][13][14][15]. In central neurons, P2Y 13 has been shown to be involved in neuronal differentiation, axonal elongation, oxidative stress and inflammatory pain behaviour [11,[16][17][18]. Peripherally, the receptor plays key roles in lipoprotein metabolism and reverse cholesterol transport [19].…”