Open AccessCalcium Signal Profiles in Vascular Endothelium from Cdh5-GCaMP8 and Cx40-GCaMP2 Mice
Author(s) -
Yen-Lin Chen,
Thomas Baker,
Frank Lee,
Bo Shui,
Jane C. Lee,
Petr Tvrdík,
Michael I. Kotlikoff,
Swapnil K. Sonkusare
Publication year - 2021
Publication title -
journal of vascular research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 74
eISSN - 1423-0135
pISSN - 1018-1172
DOI - 10.1159/000514210
Subject(s) - endothelium , calcium , mesenteric arteries , calcium imaging , calcium signaling , anatomy , receptor , voltage dependent calcium channel , endocrinology , transient receptor potential channel , medicine , biology , chemistry , microbiology and biotechnology , biochemistry , artery
Studies in Cx40-GCaMP2 mice, which express calcium biosensor GCaMP2 in the endothelium under connexin 40 promoter, have identified the unique properties of endothelial calcium signals. However, Cx40-GCaMP2 mouse is associated with a narrow dynamic range and lack of signal in the venous endothelium. Recent studies have proposed many GCaMPs (GCaMP5/6/7/8) with improved properties although their performance in endothelium-specific calcium studies is not known. Methods: We characterized a newly developed mouse line that constitutively expresses GCaMP8 in the endothelium under the VE-cadherin (Cdh5-GCaMP8) promoter. Calcium signals through endothelial IP3 receptors and TRP vanilloid 4 (TRPV4) ion channels were recorded in mesenteric arteries (MAs) and veins from Cdh5-GCaMP8 and Cx40-GCaMP2 mice. Results: Cdh5-GCaMP8 mice showed lower baseline fluorescence intensity, higher dynamic range, and higher amplitudes of individual calcium signals than Cx40-GCaMP2 mice. Importantly, Cdh5-GCaMP8 mice enabled the first recordings of discrete calcium signals in the intact venous endothelium and revealed striking differences in IP3 receptor and TRPV4 channel calcium signals between MAs and mesenteric veins. Conclusion: Our findings suggest that Cdh5-GCaMP8 mice represent significant improvements in dynamic range, sensitivity for low-intensity signals, and the ability to record calcium signals in venous endothelium.