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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

Endothelial cells cluster based on sensitivity and activate in spatially discrete ensembles. A–D) Cells of comparable sensitivity cluster. A) Plot of the grouping of cells with the highest sensitivity to ACh (top 50%). B) Plot of the cell grouping with the least sensitivity to ACh (bottom 50%). C) Composite of plots A and B. D) Plots of neighbor frequency for the high- and low-sensitivity cells normalized to the mean number of neighbors of all cells. Cells of a given sensitivity type (high or low) have significantly more neighbors of the same type. The most sensitive cells (top 50%) have more most-sensitive neighbors and fewer least-sensitive (bottom 50%) neighbors. The least-sensitive cells (bottom 50%) have more least-sensitive neighbors and fewer most-sensitive (top 50%) neighbors. E–G) Maximum intensity projection Ca2+ wave fronts showing the number of active cells at each concentration. At each concentration, all cells that respond are shown. Cell activity has been color-coded based on the time each cell is activated (green, early; red, late; color scale left side of each frame). The temporal Ca2+ pattern to 3 concentrations of ACh (3 µM, E; 30 µM, F; 300 µM, G) from the same cells shown in the upper panels (A–C). In each panel (E–G), all cells that respond to ACh are shown. At the lowest concentration (3 µM) a small number of cells initially respond (green cells). These cells then recruit some additional cells (purple and red cells). As the concentration of ACh increases (30 µM, F) more cells are activated initially (green), and these recruit additional cells (blue). At the highest concentration, almost all cells respond almost immediately (green). The decrease in time for activation of the field reveals the increased recruitment of lower sensitivity cells with higher ACh concentrations. Scale bars, 100 µm. H) Normalized frequency distribution illustrating the decreased temporal spread of cellular activation with increasing concentrations of ACh. Three increasing concentrations of ACh (3, 30, and 300 μM; n = 6) are shown. The data are a normalized frequency distribution showing the time to peak response for each cell in the endothelium.
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Figure 4: Endothelial cells cluster based on sensitivity and activate in spatially discrete ensembles. A–D) Cells of comparable sensitivity cluster. A) Plot of the grouping of cells with the highest sensitivity to ACh (top 50%). B) Plot of the cell grouping with the least sensitivity to ACh (bottom 50%). C) Composite of plots A and B. D) Plots of neighbor frequency for the high- and low-sensitivity cells normalized to the mean number of neighbors of all cells. Cells of a given sensitivity type (high or low) have significantly more neighbors of the same type. The most sensitive cells (top 50%) have more most-sensitive neighbors and fewer least-sensitive (bottom 50%) neighbors. The least-sensitive cells (bottom 50%) have more least-sensitive neighbors and fewer most-sensitive (top 50%) neighbors. E–G) Maximum intensity projection Ca2+ wave fronts showing the number of active cells at each concentration. At each concentration, all cells that respond are shown. Cell activity has been color-coded based on the time each cell is activated (green, early; red, late; color scale left side of each frame). The temporal Ca2+ pattern to 3 concentrations of ACh (3 µM, E; 30 µM, F; 300 µM, G) from the same cells shown in the upper panels (A–C). In each panel (E–G), all cells that respond to ACh are shown. At the lowest concentration (3 µM) a small number of cells initially respond (green cells). These cells then recruit some additional cells (purple and red cells). As the concentration of ACh increases (30 µM, F) more cells are activated initially (green), and these recruit additional cells (blue). At the highest concentration, almost all cells respond almost immediately (green). The decrease in time for activation of the field reveals the increased recruitment of lower sensitivity cells with higher ACh concentrations. Scale bars, 100 µm. H) Normalized frequency distribution illustrating the decreased temporal spread of cellular activation with increasing concentrations of ACh. Three increasing concentrations of ACh (3, 30, and 300 μM; n = 6) are shown. The data are a normalized frequency distribution showing the time to peak response for each cell in the endothelium.

Mentions: Examination of the distribution of cells with low and high sensitivity shows an apparent clustering of cells with comparable sensitivities (Fig. 4A–C). Although the pattern is not completely homogenous, where there is a high-sensitivity cell, there is a high probability that a neighboring cell is a high-sensitivity cell (Fig 4D). Where there is a low-sensitivity cell, there is a high probability of a neighboring cell being a low-sensitivity cell. For this analysis, from the Ca2+ signals, cells were split into the most sensitive 50% (red) and least sensitive 50% (green) (Fig. 4A–C). From the image masks, the center of each cell was identified (barycenter of polygon image masks), and the average distance from each cell mask center to its nearest neighboring center was determined (∼16 pixels). A search was then performed within twice this radius (32 pixels), to determine how many cells fall within that distance. The search was limited to exclude the outer 32 pixels of our circular image to prevent bias from edge effects (e.g., measurement from outside cells). For each of the high-sensitivity and low-sensitivity cells, the number of high-sensitivity and low-sensitivity neighboring cells within 32 pixels were measured separately (Fig. 4). In both cases, cells of a given sensitivity type (high or low) have significantly more neighbors of the same type. This data suggest that the distribution of sensitivity to ACh is spatially structured by like-sensitivity cells being clustered. The clustering creates a multicellular equivalent of the receptor field (36) that occurs in other sensory systems from which detected signals are relayed. Indeed the multicellular clustering in the endothelium appeared also to be coupled to function and to transmit Ca2+ signals to neighboring cells as waves (Fig. 2D). The temporal response to ACh activation and spread of the Ca2+ signal were therefore next examined.


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)

Endothelial cells cluster based on sensitivity and activate in spatially discrete ensembles. A–D) Cells of comparable sensitivity cluster. A) Plot of the grouping of cells with the highest sensitivity to ACh (top 50%). B) Plot of the cell grouping with the least sensitivity to ACh (bottom 50%). C) Composite of plots A and B. D) Plots of neighbor frequency for the high- and low-sensitivity cells normalized to the mean number of neighbors of all cells. Cells of a given sensitivity type (high or low) have significantly more neighbors of the same type. The most sensitive cells (top 50%) have more most-sensitive neighbors and fewer least-sensitive (bottom 50%) neighbors. The least-sensitive cells (bottom 50%) have more least-sensitive neighbors and fewer most-sensitive (top 50%) neighbors. E–G) Maximum intensity projection Ca2+ wave fronts showing the number of active cells at each concentration. At each concentration, all cells that respond are shown. Cell activity has been color-coded based on the time each cell is activated (green, early; red, late; color scale left side of each frame). The temporal Ca2+ pattern to 3 concentrations of ACh (3 µM, E; 30 µM, F; 300 µM, G) from the same cells shown in the upper panels (A–C). In each panel (E–G), all cells that respond to ACh are shown. At the lowest concentration (3 µM) a small number of cells initially respond (green cells). These cells then recruit some additional cells (purple and red cells). As the concentration of ACh increases (30 µM, F) more cells are activated initially (green), and these recruit additional cells (blue). At the highest concentration, almost all cells respond almost immediately (green). The decrease in time for activation of the field reveals the increased recruitment of lower sensitivity cells with higher ACh concentrations. Scale bars, 100 µm. H) Normalized frequency distribution illustrating the decreased temporal spread of cellular activation with increasing concentrations of ACh. Three increasing concentrations of ACh (3, 30, and 300 μM; n = 6) are shown. The data are a normalized frequency distribution showing the time to peak response for each cell in the endothelium.
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Figure 4: Endothelial cells cluster based on sensitivity and activate in spatially discrete ensembles. A–D) Cells of comparable sensitivity cluster. A) Plot of the grouping of cells with the highest sensitivity to ACh (top 50%). B) Plot of the cell grouping with the least sensitivity to ACh (bottom 50%). C) Composite of plots A and B. D) Plots of neighbor frequency for the high- and low-sensitivity cells normalized to the mean number of neighbors of all cells. Cells of a given sensitivity type (high or low) have significantly more neighbors of the same type. The most sensitive cells (top 50%) have more most-sensitive neighbors and fewer least-sensitive (bottom 50%) neighbors. The least-sensitive cells (bottom 50%) have more least-sensitive neighbors and fewer most-sensitive (top 50%) neighbors. E–G) Maximum intensity projection Ca2+ wave fronts showing the number of active cells at each concentration. At each concentration, all cells that respond are shown. Cell activity has been color-coded based on the time each cell is activated (green, early; red, late; color scale left side of each frame). The temporal Ca2+ pattern to 3 concentrations of ACh (3 µM, E; 30 µM, F; 300 µM, G) from the same cells shown in the upper panels (A–C). In each panel (E–G), all cells that respond to ACh are shown. At the lowest concentration (3 µM) a small number of cells initially respond (green cells). These cells then recruit some additional cells (purple and red cells). As the concentration of ACh increases (30 µM, F) more cells are activated initially (green), and these recruit additional cells (blue). At the highest concentration, almost all cells respond almost immediately (green). The decrease in time for activation of the field reveals the increased recruitment of lower sensitivity cells with higher ACh concentrations. Scale bars, 100 µm. H) Normalized frequency distribution illustrating the decreased temporal spread of cellular activation with increasing concentrations of ACh. Three increasing concentrations of ACh (3, 30, and 300 μM; n = 6) are shown. The data are a normalized frequency distribution showing the time to peak response for each cell in the endothelium.
Mentions: Examination of the distribution of cells with low and high sensitivity shows an apparent clustering of cells with comparable sensitivities (Fig. 4A–C). Although the pattern is not completely homogenous, where there is a high-sensitivity cell, there is a high probability that a neighboring cell is a high-sensitivity cell (Fig 4D). Where there is a low-sensitivity cell, there is a high probability of a neighboring cell being a low-sensitivity cell. For this analysis, from the Ca2+ signals, cells were split into the most sensitive 50% (red) and least sensitive 50% (green) (Fig. 4A–C). From the image masks, the center of each cell was identified (barycenter of polygon image masks), and the average distance from each cell mask center to its nearest neighboring center was determined (∼16 pixels). A search was then performed within twice this radius (32 pixels), to determine how many cells fall within that distance. The search was limited to exclude the outer 32 pixels of our circular image to prevent bias from edge effects (e.g., measurement from outside cells). For each of the high-sensitivity and low-sensitivity cells, the number of high-sensitivity and low-sensitivity neighboring cells within 32 pixels were measured separately (Fig. 4). In both cases, cells of a given sensitivity type (high or low) have significantly more neighbors of the same type. This data suggest that the distribution of sensitivity to ACh is spatially structured by like-sensitivity cells being clustered. The clustering creates a multicellular equivalent of the receptor field (36) that occurs in other sensory systems from which detected signals are relayed. Indeed the multicellular clustering in the endothelium appeared also to be coupled to function and to transmit Ca2+ signals to neighboring cells as waves (Fig. 2D). The temporal response to ACh activation and spread of the Ca2+ signal were therefore next examined.

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