Have you ever wondered why your skin doesn’t just fall off? Binding skin to the connective tissues underneath are tiny 'rivet'-like structures called hemidesmosomes – revealed here with brightly-coloured dyes under a high powered microscope. A slice through human skin shows a gap between the outer skin layers (top in green) and the connective tissue below (top in red). Using a different green dye, the bottom image shows a vital link between them – green-coloured blobs of a stretchy protein called BP230, a vital part of the hemidesmosome, dotted just above the connective tissue. Hemidesmosomes are built to withstand tough pulling forces, but they can also be destroyed by the body’s own immune system. A mysterious condition called bullous pemphigoid (BP) leaves nasty blisters between skin layers. As the causes of BP are currently unknown, a clearer picture of the hemidesmosome may help to figure out what’s going on under the skin.
Written by John Ankers
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.