Extracellular ATP is a messenger in the transduction of noxious stimuli by pain-sensing neurons (nociceptors). The cloning of the sensory neuron-specific ATP-gated ion channel P2X3 generated intense investigation into the ability of ATP to directly activate nociceptors. However, we have new evidence that sensory neurons also express members of a family of G protein-coupled receptors (P2Y receptors) that respond to ATP or related compounds and contribute to nociceptive signaling. These receptors are poorly characterized in neurons: of the 8 known family members only P2Y1 and P2Y2 have been evaluated in sensory neurons and both have been implicated in nociceptive signal transduction. P2Y receptors can be divided into 2 groups based on their coupling to signal transduction pathways; we hypothesize that Gq-coupled receptors are proalgesic while Gi- coupled receptors are analgesic. This proposal consists of 3 Specific Aims designed to identify which P2Y family members contribute to nociceptive signaling and may be useful targets for therapeutic intervention in pain.
Specific Aim 1 will use quantitative PCR, immunohistochemistry and Wester blotting techniques to determine which P2Y receptors are expressed in sensory neurons and whether expression changes in response to inflammatory injury.
Specific Aim 2 will characterize excitatory and inhibitory actions of Gq-coupled and Gi-coupled P2Y receptors in dissociated sensory neurons using calcium imaging and post-hoc immunocytochemistry.
Specific Aim 3 will examine the contribution of P2Y ADP receptors to behavioral pain response thresholds in vivo and will determine whether pharmacological or genetic manipulation of P2Y receptors is analgesic in models of acute and persistent inflammatory pain. These studies will demonstrate the contributions of a new family of receptors to sensory neuron signaling and will provide valuable insight into the mechanisms through which nucleotides act as signaling molecules in the setting of persistent pain.Experiments in this proposal will test the hypothesis that members of the P2Y family of nucleotide receptors are powerful regulators of nociceptor sensitivity that play an important role in the maintenance of persistent pain. We will directly test the possibility that manipulation of these receptors, including the use of antagonists already in development for clinical treatment of non-pain-related syndromes, is an effective analgesic treatment in animal models of persistent pain. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS056122-02
Application #
7501933
Study Section
Somatosensory and Chemosensory Systems Study Section (SCS)
Program Officer
Porter, Linda L
Project Start
2007-09-30
Project End
2011-06-30
Budget Start
2008-07-01
Budget End
2009-06-30
Support Year
2
Fiscal Year
2008
Total Cost
$324,844
Indirect Cost
Name
University of Pittsburgh
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Molliver, Derek C; Rau, Kristofer K; Jankowski, Michael P et al. (2016) Deletion of the murine ATP/UTP receptor P2Y2 alters mechanical and thermal response properties in polymodal cutaneous afferents. Neuroscience 332:223-30
Wang, Ting; Jing, Xiaotang; DeBerry, Jennifer J et al. (2013) Neurturin overexpression in skin enhances expression of TRPM8 in cutaneous sensory neurons and leads to behavioral sensitivity to cool and menthol. J Neurosci 33:2060-70
Jankowski, Michael P; Rau, Kristofer K; Soneji, Deepak J et al. (2012) Purinergic receptor P2Y1 regulates polymodal C-fiber thermal thresholds and sensory neuron phenotypic switching during peripheral inflammation. Pain 153:410-9
Molliver, Derek C; Rau, Kristofer K; McIlwrath, Sabrina L et al. (2011) The ADP receptor P2Y1 is necessary for normal thermal sensitivity in cutaneous polymodal nociceptors. Mol Pain 7:13
Vongtau, H O; Lavoie, E G; Sévigny, J et al. (2011) Distribution of ecto-nucleotidases in mouse sensory circuits suggests roles for nucleoside triphosphate diphosphohydrolase-3 in nociception and mechanoreception. Neuroscience 193:387-98
Wang, Ting; Molliver, Derek C; Jing, Xiaotang et al. (2011) Phenotypic switching of nonpeptidergic cutaneous sensory neurons following peripheral nerve injury. PLoS One 6:e28908
Malin, Sacha A; Molliver, Derek C (2010) Gi- and Gq-coupled ADP (P2Y) receptors act in opposition to modulate nociceptive signaling and inflammatory pain behavior. Mol Pain 6:21
Chen, Xiaowei; Molliver, Derek C; Gebhart, G F (2010) The P2Y2 receptor sensitizes mouse bladder sensory neurons and facilitates purinergic currents. J Neurosci 30:2365-72
Stone, Laura S; Molliver, Derek C (2009) In search of analgesia: emerging roles of GPCRs in pain. Mol Interv 9:234-51
Dussor, G; Koerber, H R; Oaklander, A L et al. (2009) Nucleotide signaling and cutaneous mechanisms of pain transduction. Brain Res Rev 60:24-35

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