Limits...
A critical role for pannexin-1 in activation of innate immune cells of the choroid plexus.

Maslieieva V, Thompson RJ - Channels (Austin) (2014)

Bottom Line: Here we have developed a novel technique for studying epiplexus cells in acutely isolated, live and intact choroid plexus.We show that epiplexus cells are potently activated by exogenous ATP, increasing their motility within the tissue.Furthermore, ATP acts at least in part through the P2X4 ionotropic purinergic receptor.

View Article: PubMed Central - PubMed

Affiliation: Hotchkiss Brain Institute; Department of Cell Biology and Anatomy; University of Calgary; Calgary, AB Canada.

ABSTRACT
Epiplexus cells are a population of innate immune cells in the choroid plexus of the brain ventricles. They are thought to contribute to the immune component of the blood-cerebrospinal-fluid-barrier (BCSFB). Here we have developed a novel technique for studying epiplexus cells in acutely isolated, live and intact choroid plexus. We show that epiplexus cells are potently activated by exogenous ATP, increasing their motility within the tissue. This ATP-induced chemokinesis required activation of pannexin-1 channels, which are expressed by the epithelial cells of the choroid plexus and not the epiplexus cells themselves. Furthermore, ATP acts at least in part through the P2X4 ionotropic purinergic receptor. Thus, the resident immune cells of the choroid plexus appear to be in communication with the epithelial cells through pannexin-1 channels.

Show MeSH
Figure 6. A model of a proposed cascade for ATP-triggered chemokinesis of epiplexus cells. P2X4 receptors on the epithelial cells may be functionally coupled to Panx1 channels. In this way, activation of P2X4 receptors by ATP would cause a release of an unidentified signaling molecule though Panx1 channels to activate chemokinesis of epiplexus cells. Our current data cannot exclude the possibility that P2X4 receptors on the epiplexus cells may contribute to the activation process.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4048302&req=5

Figure 6: Figure 6. A model of a proposed cascade for ATP-triggered chemokinesis of epiplexus cells. P2X4 receptors on the epithelial cells may be functionally coupled to Panx1 channels. In this way, activation of P2X4 receptors by ATP would cause a release of an unidentified signaling molecule though Panx1 channels to activate chemokinesis of epiplexus cells. Our current data cannot exclude the possibility that P2X4 receptors on the epiplexus cells may contribute to the activation process.

Mentions: The choroid plexus plays important roles in brain homeostasis. It produces CSF and distributes neuropeptides, growth factors and cytokines.1 The CP functions as a critical component of the blood-CSF-barrier (BCSFB) that regulates movement of molecules in and out of the brain.1,2 The CP is thought to be an important site for immune defense and resident immune cells are likely critical for this role. Here we developed a novel method for studying the CP’s resident immune cells, the epiplexus cells, in acutely isolated and intact live CP. We report that similar to other immune cells of the monocyte lineage, epiplexus cells are potently activated by exogenous ATP. The presence of Panx1 channels in the epithelial cells of the CP appears critical for this activation. Epiplexus cell activation required P2X4, but not P2X7, ionotropic purinergic receptors. Finally, ATP-induced chemokinesis of epiplexus cells required increased intracellular Ca2+ (Fig. 6).


A critical role for pannexin-1 in activation of innate immune cells of the choroid plexus.

Maslieieva V, Thompson RJ - Channels (Austin) (2014)

Figure 6. A model of a proposed cascade for ATP-triggered chemokinesis of epiplexus cells. P2X4 receptors on the epithelial cells may be functionally coupled to Panx1 channels. In this way, activation of P2X4 receptors by ATP would cause a release of an unidentified signaling molecule though Panx1 channels to activate chemokinesis of epiplexus cells. Our current data cannot exclude the possibility that P2X4 receptors on the epiplexus cells may contribute to the activation process.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4048302&req=5

Figure 6: Figure 6. A model of a proposed cascade for ATP-triggered chemokinesis of epiplexus cells. P2X4 receptors on the epithelial cells may be functionally coupled to Panx1 channels. In this way, activation of P2X4 receptors by ATP would cause a release of an unidentified signaling molecule though Panx1 channels to activate chemokinesis of epiplexus cells. Our current data cannot exclude the possibility that P2X4 receptors on the epiplexus cells may contribute to the activation process.
Mentions: The choroid plexus plays important roles in brain homeostasis. It produces CSF and distributes neuropeptides, growth factors and cytokines.1 The CP functions as a critical component of the blood-CSF-barrier (BCSFB) that regulates movement of molecules in and out of the brain.1,2 The CP is thought to be an important site for immune defense and resident immune cells are likely critical for this role. Here we developed a novel method for studying the CP’s resident immune cells, the epiplexus cells, in acutely isolated and intact live CP. We report that similar to other immune cells of the monocyte lineage, epiplexus cells are potently activated by exogenous ATP. The presence of Panx1 channels in the epithelial cells of the CP appears critical for this activation. Epiplexus cell activation required P2X4, but not P2X7, ionotropic purinergic receptors. Finally, ATP-induced chemokinesis of epiplexus cells required increased intracellular Ca2+ (Fig. 6).

Bottom Line: Here we have developed a novel technique for studying epiplexus cells in acutely isolated, live and intact choroid plexus.We show that epiplexus cells are potently activated by exogenous ATP, increasing their motility within the tissue.Furthermore, ATP acts at least in part through the P2X4 ionotropic purinergic receptor.

View Article: PubMed Central - PubMed

Affiliation: Hotchkiss Brain Institute; Department of Cell Biology and Anatomy; University of Calgary; Calgary, AB Canada.

ABSTRACT
Epiplexus cells are a population of innate immune cells in the choroid plexus of the brain ventricles. They are thought to contribute to the immune component of the blood-cerebrospinal-fluid-barrier (BCSFB). Here we have developed a novel technique for studying epiplexus cells in acutely isolated, live and intact choroid plexus. We show that epiplexus cells are potently activated by exogenous ATP, increasing their motility within the tissue. This ATP-induced chemokinesis required activation of pannexin-1 channels, which are expressed by the epithelial cells of the choroid plexus and not the epiplexus cells themselves. Furthermore, ATP acts at least in part through the P2X4 ionotropic purinergic receptor. Thus, the resident immune cells of the choroid plexus appear to be in communication with the epithelial cells through pannexin-1 channels.

Show MeSH