TY - JOUR
T1 - Protein kinase D isoforms are expressed in rat and mouse primary sensory neurons and are activated by agonists of protease-activated receptor 2
AU - Amadesi, Silvia
AU - Grant, Andrew D.
AU - Cottrell, Graeme S.
AU - Vaksman, Natalya
AU - Poole, Daniel P.
AU - Rozengurt, Enrique
AU - Bunnett, Nigel W.
PY - 2009/5/15
Y1 - 2009/5/15
N2 - Serine proteases generated during injury and inflammation cleave protease-activated receptor 2 (PAR2) on primary sensory neurons to induce neurogenic inflammation and hyperalgesia. Hyperalgesia requires sensitization of transient receptor potential vanilloid (TRPV) ion channels by mechanisms involving phospholipase C and protein kinase C (PKC). The protein kinase D (PKD) serine/threonine kinases are activated by diacylglycerol and PKCs and can phosphorylate TRPV1. Thus, PKDs may participate in novel signal transduction pathways triggered by serine proteases during inflammation and pain. However, it is not known whether PAR2 activates PKD, and the expression of PKD isoforms by nociceptive neurons is poorly characterized. By using HEK293 cells transfected with PKDs, we found that PAR2 stimulation promoted plasma membrane translocation and phosphorylation of PKD1, PKD2, and PKD3, indicating activation. This effect was partially dependent on PKCε. By immunofluorescence and confocal microscopy, with antibodies against PKD1/PKD2 and PKD3 and neuronal markers, we found that PKDs were expressed in rat and mouse dorsal root ganglia (DRG) neurons, including nociceptive neurons that expressed TRPV1, PAR2, and neuropeptides. PAR2 agonist induced phosphorylation of PKD in cultured DRG neurons, indicating PKD activation. Intraplantar injection of PAR2 agonist also caused phosphorylation of PKD in neurons of lumbar DRG, confirming activation in vivo. Thus, PKD1, PKD2, and PKD3 are expressed in primary sensory neurons that mediate neurogenic inflammation and pain transmission, and PAR2 agonists activate PKDs in HEK293 cells and DRG neurons in culture and in intact animals. PKD may be a novel component of a signal transduction pathway for protease-induced activation of nociceptive neurons and an important new target for anti-inflammatory and analgesic therapies.
AB - Serine proteases generated during injury and inflammation cleave protease-activated receptor 2 (PAR2) on primary sensory neurons to induce neurogenic inflammation and hyperalgesia. Hyperalgesia requires sensitization of transient receptor potential vanilloid (TRPV) ion channels by mechanisms involving phospholipase C and protein kinase C (PKC). The protein kinase D (PKD) serine/threonine kinases are activated by diacylglycerol and PKCs and can phosphorylate TRPV1. Thus, PKDs may participate in novel signal transduction pathways triggered by serine proteases during inflammation and pain. However, it is not known whether PAR2 activates PKD, and the expression of PKD isoforms by nociceptive neurons is poorly characterized. By using HEK293 cells transfected with PKDs, we found that PAR2 stimulation promoted plasma membrane translocation and phosphorylation of PKD1, PKD2, and PKD3, indicating activation. This effect was partially dependent on PKCε. By immunofluorescence and confocal microscopy, with antibodies against PKD1/PKD2 and PKD3 and neuronal markers, we found that PKDs were expressed in rat and mouse dorsal root ganglia (DRG) neurons, including nociceptive neurons that expressed TRPV1, PAR2, and neuropeptides. PAR2 agonist induced phosphorylation of PKD in cultured DRG neurons, indicating PKD activation. Intraplantar injection of PAR2 agonist also caused phosphorylation of PKD in neurons of lumbar DRG, confirming activation in vivo. Thus, PKD1, PKD2, and PKD3 are expressed in primary sensory neurons that mediate neurogenic inflammation and pain transmission, and PAR2 agonists activate PKDs in HEK293 cells and DRG neurons in culture and in intact animals. PKD may be a novel component of a signal transduction pathway for protease-induced activation of nociceptive neurons and an important new target for anti-inflammatory and analgesic therapies.
KW - Dorsal root ganglia
KW - GPCR
KW - Kinase
KW - Phosphorylation
KW - Serine protease
UR - http://www.scopus.com/inward/record.url?scp=69449091027&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=69449091027&partnerID=8YFLogxK
U2 - 10.1002/cne.22104
DO - 10.1002/cne.22104
M3 - Article (journal)
C2 - 19575452
AN - SCOPUS:69449091027
SN - 0021-9967
VL - 516
SP - 141
EP - 156
JO - Journal of Comparative Neurology
JF - Journal of Comparative Neurology
IS - 2
ER -