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Clusters of specialized detector cells provide sensitive and high fidelity receptor signaling in the intact endothelium.

Wilson C, Saunter CD, Girkin JM, McCarron JG - FASEB J. (2016)

Bottom Line: D., Girkin, J.M., McCarron, J.Clusters of specialized detector cells provide sensitive and high fidelity receptor signaling in the intact endothelium.

View Article: PubMed Central - PubMed

Affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom; and.

No MeSH data available.


Related in: MedlinePlus

Local photolysis of caged IP3 triggered [Ca2+]c increases, which propagate to neighboring cells. A) In a field of endothelial cells, locally photolyzed caged IP3 in a single endothelial cell (i, yellow box) increased [Ca2+]c in the activated cell (ii, green; iv, red) and a smaller response in an adjacent cell (iv, blue). The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). Immediately after photolysis (iv, ↑), a Ca2+ rise occurred in the activated cell, and a subsequent rise occurred in an adjacent cell some 20 s later. The Ca2+ changes in ii show all Ca2+ activity (i.e., each cell that responds is shown irrespective of time of response). B) IP3 photoreleased simultaneously in 2 adjacent cells (i, yellow box) evoked a Ca2+ rise in each of the activated cells (ii, green; iv, red and blue lines) and Ca2+ rise in a neighboring cell (green) some 20 s later. The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). C) Photolyzed caged IP3 in 4 cells simultaneously (i, yellow box) evoked a local Ca2+ increase, which rapidly propagated to a substantial number (∼18) of neighboring cells (ii–iv). The Ca2+ changes extended several cell lengths from the photolysis site (i, ii). The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). Scale bars, 50 µm.
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Figure 8: Local photolysis of caged IP3 triggered [Ca2+]c increases, which propagate to neighboring cells. A) In a field of endothelial cells, locally photolyzed caged IP3 in a single endothelial cell (i, yellow box) increased [Ca2+]c in the activated cell (ii, green; iv, red) and a smaller response in an adjacent cell (iv, blue). The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). Immediately after photolysis (iv, ↑), a Ca2+ rise occurred in the activated cell, and a subsequent rise occurred in an adjacent cell some 20 s later. The Ca2+ changes in ii show all Ca2+ activity (i.e., each cell that responds is shown irrespective of time of response). B) IP3 photoreleased simultaneously in 2 adjacent cells (i, yellow box) evoked a Ca2+ rise in each of the activated cells (ii, green; iv, red and blue lines) and Ca2+ rise in a neighboring cell (green) some 20 s later. The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). C) Photolyzed caged IP3 in 4 cells simultaneously (i, yellow box) evoked a local Ca2+ increase, which rapidly propagated to a substantial number (∼18) of neighboring cells (ii–iv). The Ca2+ changes extended several cell lengths from the photolysis site (i, ii). The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). Scale bars, 50 µm.

Mentions: Because the Gap junction blockers had limited use in determining if cells were coupled to progress waves among cells, another approach was taken to study cell–cell communication. Specific preselected cells were activated by locally photolyzing caged IP3 and the transmission of the Ca2+ signal from these cells was then examined (Fig. 8). Photolysis of caged IP3 in a single cell triggered a rapid rise in [Ca2+]c in the activated cell (Fig. 8A). After a significant delay (∼8 s) a small rise in Ca2+ occurred in a neighboring cell (Fig. 8A). The amplitude and spread of wave propagation to neighboring cells was determined by how many cells were activated simultaneously. Photorelease of caged IP3 in 2 cells simultaneously (Fig. 8B) triggered an immediate rise in [Ca2+]c in the activated cell and a [Ca2+]c rise in a neighboring cell. That [Ca2+]c rise was more substantial than occurred when only a single cell was activated (Fig. 8A). When 4 cells were activated simultaneously by photolysis of caged IP3 (Fig. 8C), a substantial [Ca2+]c rise propagated rapidly to a substantial number (∼18) of neighboring cells (Fig. 8C) and extended several cells lengths from the photolysis site. These experiments demonstrate that Ca2+ rises triggered in a single cell propagate to neighboring cells, presumably via direct cell–cell communication. The extent of propagation is determined by the number of cells simultaneously activated and offers a coincidence detection system that increases signal fidelity. Similar results were seen on 3 other experiments. Although these results do show cell–cell communication, the mechanisms of wave transmission arising from release of caged IP3 may not necessarily be the same as that of ACh-evoked Ca2+ waves, and the route of transmission between cells is not clear from the present findings.


Clusters of specialized detector cells provide sensitive and high fidelity receptor signaling in the intact endothelium.

Wilson C, Saunter CD, Girkin JM, McCarron JG - FASEB J. (2016)

Local photolysis of caged IP3 triggered [Ca2+]c increases, which propagate to neighboring cells. A) In a field of endothelial cells, locally photolyzed caged IP3 in a single endothelial cell (i, yellow box) increased [Ca2+]c in the activated cell (ii, green; iv, red) and a smaller response in an adjacent cell (iv, blue). The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). Immediately after photolysis (iv, ↑), a Ca2+ rise occurred in the activated cell, and a subsequent rise occurred in an adjacent cell some 20 s later. The Ca2+ changes in ii show all Ca2+ activity (i.e., each cell that responds is shown irrespective of time of response). B) IP3 photoreleased simultaneously in 2 adjacent cells (i, yellow box) evoked a Ca2+ rise in each of the activated cells (ii, green; iv, red and blue lines) and Ca2+ rise in a neighboring cell (green) some 20 s later. The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). C) Photolyzed caged IP3 in 4 cells simultaneously (i, yellow box) evoked a local Ca2+ increase, which rapidly propagated to a substantial number (∼18) of neighboring cells (ii–iv). The Ca2+ changes extended several cell lengths from the photolysis site (i, ii). The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). Scale bars, 50 µm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4836367&req=5

Figure 8: Local photolysis of caged IP3 triggered [Ca2+]c increases, which propagate to neighboring cells. A) In a field of endothelial cells, locally photolyzed caged IP3 in a single endothelial cell (i, yellow box) increased [Ca2+]c in the activated cell (ii, green; iv, red) and a smaller response in an adjacent cell (iv, blue). The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). Immediately after photolysis (iv, ↑), a Ca2+ rise occurred in the activated cell, and a subsequent rise occurred in an adjacent cell some 20 s later. The Ca2+ changes in ii show all Ca2+ activity (i.e., each cell that responds is shown irrespective of time of response). B) IP3 photoreleased simultaneously in 2 adjacent cells (i, yellow box) evoked a Ca2+ rise in each of the activated cells (ii, green; iv, red and blue lines) and Ca2+ rise in a neighboring cell (green) some 20 s later. The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). C) Photolyzed caged IP3 in 4 cells simultaneously (i, yellow box) evoked a local Ca2+ increase, which rapidly propagated to a substantial number (∼18) of neighboring cells (ii–iv). The Ca2+ changes extended several cell lengths from the photolysis site (i, ii). The time course of the [Ca2+]c changes, from the cells indicated by the regions of interest (iii), are shown in the line trace (iv). Scale bars, 50 µm.
Mentions: Because the Gap junction blockers had limited use in determining if cells were coupled to progress waves among cells, another approach was taken to study cell–cell communication. Specific preselected cells were activated by locally photolyzing caged IP3 and the transmission of the Ca2+ signal from these cells was then examined (Fig. 8). Photolysis of caged IP3 in a single cell triggered a rapid rise in [Ca2+]c in the activated cell (Fig. 8A). After a significant delay (∼8 s) a small rise in Ca2+ occurred in a neighboring cell (Fig. 8A). The amplitude and spread of wave propagation to neighboring cells was determined by how many cells were activated simultaneously. Photorelease of caged IP3 in 2 cells simultaneously (Fig. 8B) triggered an immediate rise in [Ca2+]c in the activated cell and a [Ca2+]c rise in a neighboring cell. That [Ca2+]c rise was more substantial than occurred when only a single cell was activated (Fig. 8A). When 4 cells were activated simultaneously by photolysis of caged IP3 (Fig. 8C), a substantial [Ca2+]c rise propagated rapidly to a substantial number (∼18) of neighboring cells (Fig. 8C) and extended several cells lengths from the photolysis site. These experiments demonstrate that Ca2+ rises triggered in a single cell propagate to neighboring cells, presumably via direct cell–cell communication. The extent of propagation is determined by the number of cells simultaneously activated and offers a coincidence detection system that increases signal fidelity. Similar results were seen on 3 other experiments. Although these results do show cell–cell communication, the mechanisms of wave transmission arising from release of caged IP3 may not necessarily be the same as that of ACh-evoked Ca2+ waves, and the route of transmission between cells is not clear from the present findings.

Bottom Line: D., Girkin, J.M., McCarron, J.Clusters of specialized detector cells provide sensitive and high fidelity receptor signaling in the intact endothelium.

View Article: PubMed Central - PubMed

Affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom; and.

No MeSH data available.


Related in: MedlinePlus