ATP affects both axons and Schwann cells of unmyelinated C fibres

Irnich, Dominik; Burgstahler, Ralf; Bostock, Hugh; Grafe, Peter

doi:10.1016/s0304-3959(01)00277-9

Cited by 55 publications

(33 citation statements)

References 27 publications

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“…There are considerable data that Schwann cells in intact peripheral nerve preparations respond to application of extracellular ATP with a rise in intracellular Ca 2ϩ concentrations (Lyons et al, 1995;Mayer et al, 1998;Irnich et al, 2001). Interestingly, the sensitivity to ATP is not restricted to nonmyelinating Schwann cells but can also be observed in myelinating Schwann cells, including the paranodal Schwann cell region (Mayer et al, 1997).…”

Section: Discussionmentioning

confidence: 99%

Association of the ecto‐ATPase NTPDase2 with glial cells of the peripheral nervous system

Braun

Sévigny²,

Robson

et al. 2003

Glia

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Cellular signaling via extracellular nucleotides appears to play a major role in the functioning of the peripheral nervous system. Information regarding the functional characterization of nucleotide P2 receptors or their expression pattern has been accumulating rapidly; however, very little is known regarding the distribution of ecto-nucleotidases in the periphery. The extracellular level of nucleotides is controlled by ecto-nucleotidases, whereby the three membrane-bound members of the ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) family are of special functional importance. Using enzyme histochemistry and immunostaining, we demonstrate that NTPDase2 is associated with nonmyelinating Schwann cells of the rat sciatic nerve, whereas NTPDase1 is restricted to blood vessel walls. NTPDase2 immunoreactivity was detected from embryonic day E18 onward, suggesting that immature Schwann cells express the enzyme. With the onset of myelination, NTPDase2 immunoreactivity remained associated solely with nonmyelinating Schwann cells. NTPDase2 was absent from perisynaptic Schwann cells but was associated with fibroblasts covering the endplate at some distance. In addition, NTPDase2 immunoreactivity was associated with the satellite glial cells in dorsal root ganglia and sympathetic ganglia, and with the enteric glia surrounding the cell bodies of ganglionic neurons of the myenteric and the submucous plexus. In contrast to NTPDase1, NTPDase2 preferentially hydrolyzes nucleoside triphosphates over nucleoside diphosphates and thus can act either in inactivating or in producing P2 receptor ligands. Our results suggest that NTPDase2 plays an important role in the control of nucleotide-mediated activation of peripheral neurons or glia and in the dialogue between these two cell types.

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Section: Discussionmentioning

confidence: 99%

Association of the ecto‐ATPase NTPDase2 with glial cells of the peripheral nervous system

Braun

Sévigny²,

Robson

et al. 2003

Glia

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“…Several studies have described the responses of glial cells to ATP, including Schwann cells (6,85,167,170,208,490; reviewed in Ref. 476).…”

Section: Glial Cellsmentioning

confidence: 99%

“…In animals, afferent C fibers are directly excited by ATP and ␣␤meATP (heart, Ref. 208). In some of these cases, the effectiveness of ␣␤meATP and the antagonism by TNP-ATP indicate involvement of a receptor that contains a P2X 3 subunit.…”

Section: Sensory Fibers In the Peripherymentioning

confidence: 99%

Molecular Physiology of P2X Receptors

North

2002

Physiological Reviews

2,683

128

3,397

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P2X receptors are membrane ion channels that open in response to the binding of extracellular ATP. Seven genes in vertebrates encode P2X receptor subunits, which are 40–50% identical in amino acid sequence. Each subunit has two transmembrane domains, separated by an extracellular domain (∼280 amino acids). Channels form as multimers of several subunits. Homomeric P2X1, P2X2, P2X3, P2X4, P2X5, and P2X7 channels and heteromeric P2X2/3 and P2X1/5 channels have been most fully characterized following heterologous expression. Some agonists (e.g., αβ-methylene ATP) and antagonists [e.g., 2′,3′- O-(2,4,6-trinitrophenyl)-ATP] are strongly selective for receptors containing P2X1 and P2X3subunits. All P2X receptors are permeable to small monovalent cations; some have significant calcium or anion permeability. In many cells, activation of homomeric P2X7 receptors induces a permeability increase to larger organic cations including some fluorescent dyes and also signals to the cytoskeleton; these changes probably involve additional interacting proteins. P2X receptors are abundantly distributed, and functional responses are seen in neurons, glia, epithelia, endothelia, bone, muscle, and hemopoietic tissues. The molecular composition of native receptors is becoming understood, and some cells express more than one type of P2X receptor. On smooth muscles, P2X receptors respond to ATP released from sympathetic motor nerves (e.g., in ejaculation). On sensory nerves, they are involved in the initiation of afferent signals in several viscera (e.g., bladder, intestine) and play a key role in sensing tissue-damaging and inflammatory stimuli. Paracrine roles for ATP signaling through P2X receptors are likely in neurohypophysis, ducted glands, airway epithelia, kidney, bone, and hemopoietic tissues. In the last case, P2X7 receptor activation stimulates cytokine release by engaging intracellular signaling pathways.

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“…These cells were found to respond to ATP (via P2Y receptors) by elevation of intracellular Ca 2+ [57]. Following activation by ATP these cells transmit signals to sensory axons, and thus may contribute to nociception [79]. The significance of the work on ATP in these two types of peripheral glial cells is in showing that not only neurons, but also glial cells should be taken into consideration when sensory signaling, and in particular, nociception, are discussed.…”

Section: Adenosine Triphosphate (Atp)mentioning

confidence: 99%