Microtubule stabilization opposes the (TNF-α)-induced loss in the barrier integrity of corneal endothelium

• Published in: Experimental eye research Vol. 89; no. 6; pp. 950 - 959
• Main Authors: Shivanna, Mahesh, Srinivas, Sangly P.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-12-2009
• Subjects: barrier integrity; Cadherins - metabolism; Cells, Cultured; corneal endothelium; Dextrans - pharmacokinetics; Electric Impedance; Endothelium, Corneal - drug effects; Endothelium, Corneal - physiology; Endothelium, Corneal - ultrastructure; Epothilones - pharmacology; Fluorescein-5-isothiocyanate - analogs & derivatives; Fluorescein-5-isothiocyanate - pharmacokinetics; Humans; Membrane Proteins - metabolism; microtubules; Microtubules - drug effects; Microtubules - physiology; paclitaxel; Paclitaxel - pharmacology; Permeability - drug effects; Phosphoproteins - metabolism; TNF-alpha; Tubulin Modulators - pharmacology; Tumor Necrosis Factor-alpha - pharmacology; Zonula Occludens-1 Protein; paclitaxel; corneal endothelium; barrier integrity; microtubules; TNF-alpha
• ISSN: 0014-4835; 1096-0007
• DOI: 10.1016/j.exer.2009.08.004

Microtubule disassembly breaks down the barrier integrity in a number of epithelial and endothelial monolayers. This study has investigated effects of TNF-α, which is implicated in corneal allograft rejection, on microtubules and barrier integrity in cultured bovine corneal endothelial cells. Exposure to TNF-α led to disassembly of the microtubules, and also caused disruption of the perijunctional actomyosin ring (PAMR). As a measure of barrier integrity, trans-endothelial electrical resistance (TER) was determined based on electrical cell-substrate impedance sensing in realtime. Exposure to TNF-α caused a slow decline in TER for > 20 h, and a similar exposure to cells grown on porous culture inserts led to a significant increase in permeability to FITC dextran. These changes, indicating a loss of barrier integrity, were also reflected by dislocation of ZO-1 at the cell border and disassembly of cadherins. These effects of TNF-α were inhibited upon stabilization of microtubules by pre-treatment with paclitaxel or epothilone B. Microtubule stabilization may be a useful strategy to overcome (TNF-α)-induced loss of the barrier integrity of corneal endothelium during inflammation associated with transplant rejection and uveitis.