Gap Junction Localization and Connexin Expression in Cytochemically Identified Endothelial Cells of Arterial Tissue
Overview
Authors
Affiliations
Vascular endothelial cells interact with one another via gap junctions, but information on the precise connexin make-up of endothelial gap junctions in intact arterial tissue is limited. One factor contributing to this lack of information is that standard immunocytochemical methodologies applied to arterial sections do not readily permit unequivocal localization of connexin immunolabeling to endothelium. Here we introduce a method for multiple labeling with specific endothelial cell markers and one or more connexin-specific antibodies which overcomes this limitation. Applying this method to localize connexins 43, 40, and 37 by confocal microscopy, we show that the three connexin types have quite distinctive labeling patterns in different vessels. Whereas endothelial cells of rat aorta and coronary artery characteristically show extensive, prominent connexin40, and heterogeneous scattered connexin37, the former, unlike the latter, also has abundant connexin43. The relative lack of connexin43 in coronary artery endothelium was confirmed in both rat and human using three alternative antibodies. In the aorta, connexins43 and 40 commonly co-localize to the same junctional plaque. Even within a given type of endothelium, zonal variation in connexin expression was apparent. In rat endocardium, a zone just below the mitral valve region is marked by expression of greater quantities of connexin43 than surrounding areas. These results are consistent with the idea that differential expression of connexins may contribute to modulation of endothelial gap junction function in different segments and subzones of the arterial system.
Connexin 43 across the Vasculature: Gap Junctions and Beyond.
Sedovy M, Leng X, Leaf M, Iqbal F, Payne L, Chappell J J Vasc Res. 2022; 60(2):101-113.
PMID: 36513042 PMC: 11073551. DOI: 10.1159/000527469.
Polarized Proteins in Endothelium and Their Contribution to Function.
Wolpe A, Ruddiman C, Hall P, Isakson B J Vasc Res. 2021; 58(2):65-91.
PMID: 33503620 PMC: 7954879. DOI: 10.1159/000512618.
Chloroquine differentially modulates coronary vasodilation in control and diabetic mice.
Zhang Q, Tsuji-Hosokawa A, Willson C, Watanabe M, Si R, Lai N Br J Pharmacol. 2019; 177(2):314-327.
PMID: 31503328 PMC: 6989957. DOI: 10.1111/bph.14864.
Okamoto T, Suzuki K Int J Mol Sci. 2017; 18(11).
PMID: 29077057 PMC: 5713224. DOI: 10.3390/ijms18112254.
Age-related Impairment of Vascular Structure and Functions.
Xu X, Wang B, Ren C, Hu J, Greenberg D, Chen T Aging Dis. 2017; 8(5):590-610.
PMID: 28966804 PMC: 5614324. DOI: 10.14336/AD.2017.0430.