Limits...
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

Dynamics of Ca2+ wave propagation. Ca2+ waves appear to progress both within and between cells. A) Ca2+ signaling activity between endothelial cells. B) A kymograph (across yellow line in A) shows apparent bidirectional transmission of Ca2+ waves (rises in [Ca2+]c are shown as lighter shades and declines are shown as darker shades) across 2 endothelial cells. The sequence of activation is not constant revealing the changing direction of the wave. C) Plots of Ca2+ signal from the same 2 cells (A, B) show the changes in timing of the 2 signals. The time of Ca2+ rise changes. D) The effects of Gap junction and ATP receptor blockers on the ACh-evoked endothelial response. Normalized summary data showing the average amplitude of the peak ACh-evoked (100 μM) response (gray) and the number of cells activated (red). The average ACh-evoked endothelial Ca2+ response, but not the number of activated cells was significantly reduced by CBX (100 μM, n = 3) and 18βGA (100 μM, n = 3). ACh-evoked responses persisted in the presence of suramin (100 μM, n = 3) and apyrase (4 U/ml). Gap27 (500 µM), a peptide-based connexin 43 mimetic, reduced the amplitude of the Ca2+ responses in each cell activated but not the number of activated cells. Data presented as means ± sem and normalized to control (no treatment, 1; not shown), *P < 0.05. E) Baseline-corrected ACh-evoked endothelial Ca2+ signals (F/F0) from ∼150 cells in the absence (top) and presence (bottom) of Gap27. F) Baseline-corrected (unaligned) endothelial Ca2+ signals (F/F0) from 6 cells in an unstimulated artery incubated with 18βGA (100 μM). Recordings are from a time-lapse experiment in which images were acquired at 10-s intervals, and start approximately 60 min after introduction of 18βGA. Signals in both panels have been temporally smoothed with a 10-point running average. The blockers, by themselves, cause a significant Ca2+ rise after prolonged incubation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4836367&req=5

Figure 7: Dynamics of Ca2+ wave propagation. Ca2+ waves appear to progress both within and between cells. A) Ca2+ signaling activity between endothelial cells. B) A kymograph (across yellow line in A) shows apparent bidirectional transmission of Ca2+ waves (rises in [Ca2+]c are shown as lighter shades and declines are shown as darker shades) across 2 endothelial cells. The sequence of activation is not constant revealing the changing direction of the wave. C) Plots of Ca2+ signal from the same 2 cells (A, B) show the changes in timing of the 2 signals. The time of Ca2+ rise changes. D) The effects of Gap junction and ATP receptor blockers on the ACh-evoked endothelial response. Normalized summary data showing the average amplitude of the peak ACh-evoked (100 μM) response (gray) and the number of cells activated (red). The average ACh-evoked endothelial Ca2+ response, but not the number of activated cells was significantly reduced by CBX (100 μM, n = 3) and 18βGA (100 μM, n = 3). ACh-evoked responses persisted in the presence of suramin (100 μM, n = 3) and apyrase (4 U/ml). Gap27 (500 µM), a peptide-based connexin 43 mimetic, reduced the amplitude of the Ca2+ responses in each cell activated but not the number of activated cells. Data presented as means ± sem and normalized to control (no treatment, 1; not shown), *P < 0.05. E) Baseline-corrected ACh-evoked endothelial Ca2+ signals (F/F0) from ∼150 cells in the absence (top) and presence (bottom) of Gap27. F) Baseline-corrected (unaligned) endothelial Ca2+ signals (F/F0) from 6 cells in an unstimulated artery incubated with 18βGA (100 μM). Recordings are from a time-lapse experiment in which images were acquired at 10-s intervals, and start approximately 60 min after introduction of 18βGA. Signals in both panels have been temporally smoothed with a 10-point running average. The blockers, by themselves, cause a significant Ca2+ rise after prolonged incubation.

Mentions: After the initial Ca2+ waves decoupled into multiple spatially restricted events, the Ca2+ changes did not subsequently entrain and synchronize, to become a uniform oscillation throughout the endothelium, or co-ordinate to move in a particular direction. However, waves still appeared to progress within cells, and close inspection revealed small groupings of cells that appeared to remain linked by the apparent transmission of the oscillatory Ca2+ waves between cells (Fig. 7A–C). However, the direction of wave travel between the apparently linked cells was not fixed and could reverse rapidly (Fig. 7A–C). These observations raised the question of whether cells were coupled and acted as conduit for Ca2+ signal progression along the endothelium or if cells were completely uncoupled and the Ca2+ rises in each cell were independent but temporally coincident to create the impression of wave progression. Coincidental sequential activation could, for example, arise from the time required for the concentration of ACh to change after addition and the various sensitivities of cells to ACh.


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)

Dynamics of Ca2+ wave propagation. Ca2+ waves appear to progress both within and between cells. A) Ca2+ signaling activity between endothelial cells. B) A kymograph (across yellow line in A) shows apparent bidirectional transmission of Ca2+ waves (rises in [Ca2+]c are shown as lighter shades and declines are shown as darker shades) across 2 endothelial cells. The sequence of activation is not constant revealing the changing direction of the wave. C) Plots of Ca2+ signal from the same 2 cells (A, B) show the changes in timing of the 2 signals. The time of Ca2+ rise changes. D) The effects of Gap junction and ATP receptor blockers on the ACh-evoked endothelial response. Normalized summary data showing the average amplitude of the peak ACh-evoked (100 μM) response (gray) and the number of cells activated (red). The average ACh-evoked endothelial Ca2+ response, but not the number of activated cells was significantly reduced by CBX (100 μM, n = 3) and 18βGA (100 μM, n = 3). ACh-evoked responses persisted in the presence of suramin (100 μM, n = 3) and apyrase (4 U/ml). Gap27 (500 µM), a peptide-based connexin 43 mimetic, reduced the amplitude of the Ca2+ responses in each cell activated but not the number of activated cells. Data presented as means ± sem and normalized to control (no treatment, 1; not shown), *P < 0.05. E) Baseline-corrected ACh-evoked endothelial Ca2+ signals (F/F0) from ∼150 cells in the absence (top) and presence (bottom) of Gap27. F) Baseline-corrected (unaligned) endothelial Ca2+ signals (F/F0) from 6 cells in an unstimulated artery incubated with 18βGA (100 μM). Recordings are from a time-lapse experiment in which images were acquired at 10-s intervals, and start approximately 60 min after introduction of 18βGA. Signals in both panels have been temporally smoothed with a 10-point running average. The blockers, by themselves, cause a significant Ca2+ rise after prolonged incubation.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 7: Dynamics of Ca2+ wave propagation. Ca2+ waves appear to progress both within and between cells. A) Ca2+ signaling activity between endothelial cells. B) A kymograph (across yellow line in A) shows apparent bidirectional transmission of Ca2+ waves (rises in [Ca2+]c are shown as lighter shades and declines are shown as darker shades) across 2 endothelial cells. The sequence of activation is not constant revealing the changing direction of the wave. C) Plots of Ca2+ signal from the same 2 cells (A, B) show the changes in timing of the 2 signals. The time of Ca2+ rise changes. D) The effects of Gap junction and ATP receptor blockers on the ACh-evoked endothelial response. Normalized summary data showing the average amplitude of the peak ACh-evoked (100 μM) response (gray) and the number of cells activated (red). The average ACh-evoked endothelial Ca2+ response, but not the number of activated cells was significantly reduced by CBX (100 μM, n = 3) and 18βGA (100 μM, n = 3). ACh-evoked responses persisted in the presence of suramin (100 μM, n = 3) and apyrase (4 U/ml). Gap27 (500 µM), a peptide-based connexin 43 mimetic, reduced the amplitude of the Ca2+ responses in each cell activated but not the number of activated cells. Data presented as means ± sem and normalized to control (no treatment, 1; not shown), *P < 0.05. E) Baseline-corrected ACh-evoked endothelial Ca2+ signals (F/F0) from ∼150 cells in the absence (top) and presence (bottom) of Gap27. F) Baseline-corrected (unaligned) endothelial Ca2+ signals (F/F0) from 6 cells in an unstimulated artery incubated with 18βGA (100 μM). Recordings are from a time-lapse experiment in which images were acquired at 10-s intervals, and start approximately 60 min after introduction of 18βGA. Signals in both panels have been temporally smoothed with a 10-point running average. The blockers, by themselves, cause a significant Ca2+ rise after prolonged incubation.
Mentions: After the initial Ca2+ waves decoupled into multiple spatially restricted events, the Ca2+ changes did not subsequently entrain and synchronize, to become a uniform oscillation throughout the endothelium, or co-ordinate to move in a particular direction. However, waves still appeared to progress within cells, and close inspection revealed small groupings of cells that appeared to remain linked by the apparent transmission of the oscillatory Ca2+ waves between cells (Fig. 7A–C). However, the direction of wave travel between the apparently linked cells was not fixed and could reverse rapidly (Fig. 7A–C). These observations raised the question of whether cells were coupled and acted as conduit for Ca2+ signal progression along the endothelium or if cells were completely uncoupled and the Ca2+ rises in each cell were independent but temporally coincident to create the impression of wave progression. Coincidental sequential activation could, for example, arise from the time required for the concentration of ACh to change after addition and the various sensitivities of cells to ACh.

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