You likely know how important it is to maintain, repair, and even remodel your home as it gets older. Hypothetically, maybe your dog has chewed off your bedroom door’s frame in an attempt to greet your dinner guests, or maybe your toddler has drawn an abstract mural on your walls. Whatever the case, you head to your garage to find those necessary, but frequently overlooked, tools. Our cells are no different (except for dog- and toddler-induced damage). Today’s image is from a paper describing structures that are seen during cell-cell junction remodeling.
Endothelial cells line our blood vessels and maintain stable cell-cell junctions between one another to provide a tight barrier for our blood. These adherens junctions are damaged in cases of inflammation, atherosclerosis, and tumor angiogenesis, via endothelial signals and hormones. Vascular endothelial cadherin (VE-cadherin) is the central component of adherens junctions in these cells, and a recent paper by Huveneers and colleagues describes the finding that VE cadherin is found on both stable adherens junctions as well sites of junction remodeling called focal adherens junctions (FAJs). These newly-characterized FAJs are attached to actin bundles and contain Vinculin, which protects the junctions from opening during remodeling. In addition, FAJs were under pulling forces from the actin cytoskeleton during remodeling. Images above show human endothelial cells with FAJs (middle row, box 1) and stable adherens junctions (bottom row, box 2). Vinculin can be seen on FAJs, but not on stable junctions.
BONUS!! Check out some very cool movies of remodeling junctions here and here. All movies from this paper can be found here.
DOUBLE BONUS!! Not surprisingly, the author’s beautiful images impressed JCB so much that they made the cover here.
Huveneers, S., Oldenburg, J., Spanjaard, E., van der Krogt, G., Grigoriev, I., Akhmanova, A., Rehmann, H., & de Rooij, J. (2012). Vinculin associates with endothelial VE-cadherin junctions to control force-dependent remodeling originally published in the Journal of Cell Biology, 196 (5), 641-652 DOI: 10.1083/jcb.201108120