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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.

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Figure 5. Ca2+ is involved in mediating chemokinesis. Absence of extracellular Ca2+ and chelation of intracellular Ca2+ significantly decreased ATP-triggered chemokinesis. (A) Normalized average distance and statistical analysis, each symbol represents an individual cell; (B) normalized summative distance; (C) slope of normalized summative distance where each symbol represents the average of all cells in a given CP.
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Figure 5: Figure 5. Ca2+ is involved in mediating chemokinesis. Absence of extracellular Ca2+ and chelation of intracellular Ca2+ significantly decreased ATP-triggered chemokinesis. (A) Normalized average distance and statistical analysis, each symbol represents an individual cell; (B) normalized summative distance; (C) slope of normalized summative distance where each symbol represents the average of all cells in a given CP.

Mentions: Ionotropic purinergic receptors signal via the influx of Ca2+.23 To investigate if ATP is mediating the chemokinesis of epiplexus cells via Ca2+ influx through P2X receptors, we used a Ca2+-free aCSF. Removal of extracellular Ca2+ did not change baseline motility (0.23 ± 0.08 μm/5 min without Ca2+; P > 0.99 compared with control, n = 161 cells from 5 CPs). However, the absence of Ca2+ significantly altered ATP-induced chemokinesis of epiplexus cells to 0.62 ± 0.08 μm/5 min (n = 276 cells from 6 CPs), which was significantly different from ATP in regular aCSF (P = 0.04), but also from the rate in control conditions (P = 0.004) (Fig. 5).


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

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

Figure 5. Ca2+ is involved in mediating chemokinesis. Absence of extracellular Ca2+ and chelation of intracellular Ca2+ significantly decreased ATP-triggered chemokinesis. (A) Normalized average distance and statistical analysis, each symbol represents an individual cell; (B) normalized summative distance; (C) slope of normalized summative distance where each symbol represents the average of all cells in a given CP.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 5: Figure 5. Ca2+ is involved in mediating chemokinesis. Absence of extracellular Ca2+ and chelation of intracellular Ca2+ significantly decreased ATP-triggered chemokinesis. (A) Normalized average distance and statistical analysis, each symbol represents an individual cell; (B) normalized summative distance; (C) slope of normalized summative distance where each symbol represents the average of all cells in a given CP.
Mentions: Ionotropic purinergic receptors signal via the influx of Ca2+.23 To investigate if ATP is mediating the chemokinesis of epiplexus cells via Ca2+ influx through P2X receptors, we used a Ca2+-free aCSF. Removal of extracellular Ca2+ did not change baseline motility (0.23 ± 0.08 μm/5 min without Ca2+; P > 0.99 compared with control, n = 161 cells from 5 CPs). However, the absence of Ca2+ significantly altered ATP-induced chemokinesis of epiplexus cells to 0.62 ± 0.08 μm/5 min (n = 276 cells from 6 CPs), which was significantly different from ATP in regular aCSF (P = 0.04), but also from the rate in control conditions (P = 0.004) (Fig. 5).

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
Related in: MedlinePlus