Measurement of shear stress-mediated intracellular calcium dynamics in human dermal lymphatic endothelial cells.
Bottom Line: Removal of the extracellular calcium from the buffer or pharmocological blockade of calcium release-activated calcium (CRAC) channels significantly reduced the peak [Ca(2+)]i, demonstrating a role of extracellular calcium entry.Inhibition of endoplasmic reticulum (ER) calcium pumps showed the importance of intracellular calcium stores in the initiation of this signal.In conclusion, we demonstrated that the shear-mediated calcium signal is dependent on the magnitude of the shear and involves ER store calcium release and extracellular calcium entry.
Affiliation: Department of Bioengineering, Imperial College, London, England;Show MeSH
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Mentions: The specific role of calcium release-activated calcium (CRAC) channels in mediating Ca2+ entry in response to the ER calcium release was investigated by inhibiting these channels using Syntha66 (also known as S66, a specific CRAC channel blocker) (14, 29, 36), thereby revealing their contribution to the shear-mediated [Ca2+]i signal (Fig. 5, A and B). Blockade of CRAC channels decreased the height of both the first (1.02 ± 0.03) and second peaks (0.73 ± 0.01) relative to their untreated controls (Fig. 5C). Moreover, S66 treatment often produced a delay of about 2–5 min in the shear-induced calcium response. Specifically, S66 increased the time to reach the first peak to 5.2 ± 0.4 min (2- to 5-min delay + an increase with a rate of 0.165 ratio/min; Table 1) compared with 1.8 ± 0.1 min without CRAC channel blockade (Fig. 5, A and B).
Affiliation: Department of Bioengineering, Imperial College, London, England;