Lymphatic endothelial cell junctional complex (LEC junction)

The lymphatic endothelial cell (LEC) junctional complex is a specialized structural and functional unit that regulates the movement of fluid, macromolecules, and cells between the interstitium and the lymphatic system. These junctions exist in two distinct morphological states: discontinuous 'button-like' junctions in initial lymphatic capillaries, which facilitate the uptake of interstitial fluid and immune cells, and continuous 'zipper-like' junctions in collecting vessels, which prevent leakage during lymph transport. The complex is composed of various proteins, including Vascular endothelial cadherin (VE-cadherin), claudins, and junctional adhesion molecules (JAMs), and its architecture is dynamically regulated by signaling pathways such as VEGFR3, Angiopoietin-2/Tie2, and Rho-associated protein kinase (ROCK). Dysregulation of these junctions is implicated in several pathologies, including lymphedema, where impaired drainage leads to tissue swelling, and cancer, where tumor cells exploit junctional openings for metastasis. Therapeutic strategies targeting these junctions aim to either promote 'zippering' to prevent lipid absorption in obesity or 'opening' to enhance fluid clearance in lymphedema.

Other names

Lymphatic endothelial cell junctionsLymphatic button junctionsLymphatic zipper junctionsUnspecified molecular target on lymphatic endothelial cell junctionsLymphatic adherens junctionsLymphatic tight junctions

Modulation of paracellular permeability through the remodeling of button-like and zipper-like junctions to regulate fluid drainage, immune cell entry, or nutrient absorption.