New aspects of the molecular constituents of tissue barriers

Abstract

Epithelial and endothelial tissue barriers are based on tight intercellular contacts (Tight Junctions, TJs) between neighbouring cells. TJs are multimeric complexes, located at the most apical border of the lateral membrane. So far, a plethora of proteins locating at tight intercellular contacts have been discovered, the role of which has just partly been unraveled. Yet, there is convincing evidence that many TJ proteins exert a dual role: They act as structural components at the junctional site and they are involved in signalling pathways leading to alterations of gene expression and cell behaviour (migration, proliferation). This review will shortly summarize the classical functions of TJs and TJ-related proteins and will introduce a new category, termed the "non-classical" functions of junctional proteins. A particular focus will be directed towards the nuclear targeting of junctional proteins and the downstream effects elicited by their intranuclear activities.

Molecular Characterisation of Transport Mechanisms at the Developing Mouse Blood–CSF Interface: A Transcriptome Approach

“…The physiological function of tight junction complexes in restricting paracellular diffusion between blood and the CSF is present very early in development [38], [39]. Key ultrastructural components such as the number and complexity of protein strands that make up the junction have been shown not to change significantly between very early gestation and adult [40].…”

“…These intracellular proteins are important components of the tight junction complex structure for two reasons: firstly they anchor the junction to the cytoskeleton; and secondly they may help to regulate the overall function of the structure [38]. Though these molecules are important for junction integrity they are not definitive for the barriers of the brain, but are more broadly components of tight junctions throughout the body [38]. The specific brain barrier accessory proteins Pard3 and Cingulin-like 1 ( jacop ) described by Daneman et al [2] were unchanged in the lateral ventricular choroid plexus in development.…”

Retinoic acid and hydrocortisone strengthen the barrier function of human RPMI 2650 cells, a model for nasal epithelial permeability

“…Intercellular junctions are involved in the control of epithelial paracellular permeability (Deli 2009). They also promote cell-to-cell communication and transfer signals that mediate contact inhibition of cell growth, increase resistance to apoptosis, and regulate cell shape and polarity (Bauer et al 2011).…”

Cranberry and Grape Juices Affect Tight Junction Function and Structural Integrity of Rotavirus-Infected Monkey Kidney Epithelial Cell Monolayers

“…Tight junctions (TJs) hold cells together, maintain cell polarity, and serve as a barrier preventing unregulated passage/loss of body fluids and electrolytes through spaces between cells (Bauer et al 2010). Some bacteria (e.g., enteropathogenic Escherichia coli), viruses (e.g., rotavirus), and intestinal parasites (e.g., Giardia lamblia) target TJs of intestinal epithelium and adversely affect barrier function and structural integrity of TJs (Buret et al 2002;Muza-Moons et al 2004;Nava et al 2004).…”