
<ArticleTitle>Effect of H-7 on cultured human trabecular meshwork cells.</ArticleTitle>
<AbstractText>PURPOSE: To determine the effect of the serine-threonine kinase inhibitor H-7, which blocks actomyosin contractility and increases outflow facility in live monkeys, on morphology, cytoskeleton, and cellular adhesions of human trabecular meshwork (HTM) cells in culture. METHODS: Cultured HTM cells were videographically recorded and evaluated before and after exposure to H-7 at different concentrations. The subcellular distribution of the actin-based cytoskeleton and associated anchor proteins including <prot>vinculin</prot>, <prot>paxillin</prot>, and <prot>beta-catenin</prot>, as well as phosphotyrosine-containing proteins were evaluated by fluorescence immunocytochemistry and digital fluorescence microscopy. RESULTS: H-7 induced pronounced but reversible HTM cell thickening toward the cell center and deterioration of the <prot>actin</prot> cytoskeletal network. Cell-extracellular matrix (ECM) and cell-cell adhesions were also affected, but the <prot>beta-catenin</prot>-rich, <prot>vinculin</prot>-containing adherens junctions were clearly more resistant than focal contacts. Phosphotyrosine labeling in focal contacts was highly sensitive to H-7. CONCLUSIONS: H-7 induces alterations in cell shape, actin cytoskeleton, and associated focal adhesions in cultured HTM cells, which may be responsible for the effects of H-7 on outflow facility in live monkey eyes.</AbstractText>
