In Human Lymphatic Glycocalyx Identification by Electron Microscopy and Immunohistochemistry

BACKGROUND Blood flow is translated into biochemical inflammatory or anti-inflammatory messages based on the type of shear stress, by means of sensitive receptors located on the endothelium. Recognition of the phenomenon is of paramount importance for the advancement in the understanding of the pathophysiological processes of vascular remodeling.The endothelial glycocalyx is a pericellular matrix, identified in both arteries and veins, acting as sensors responsive to the flow changes. Venous and lymphatic physiology is interconnected; however, to our knowledge, a lymphatic glycocalyx-like structure has never been identified in humans. The objective of this investigation is to identify glycocalyx-like structures from ex vivo lymphatic human samples. METHODS Lower limb vein and lymphatic vessels were harvested. The samples were analyzed by electron microscopy. The specimens were also examined by immunohistochemistry. RESULTS Scanning electron microscopic identified a glycocalyx-like structure in both venous and lymphatic structures. Immunohistochemistry for podoplanin, glypican-1, mucin-2, agrin and brevican characterized both the lymphatic and venous structures. CONCLUSIONS To our knowledge, the present work reports the first identification of a glycocalyx-like structure in the human lymphatic. The vasculoprotective action of the GCX could become an investigational target in the lymphatic system as well, with clinical implications for the many patients affected by lymphatic disorders.