Effect of latrunculin-A on morphology and actin-associated adhesions of cultured human trabecular meshwork cells.
OBJECTIVE
Determine the effects of the actin cytoskeleton disrupting compound latrunculin-A (LAT-A) on morphology, cytoskeleton, and cellular adhesions of cultured human trabecular meshwork (HTM) cells.


METHODS
HTM cells were cultured to high confluence with endothelial-like morphology and treated with LAT-A at different doses and duration. Topography of living cells was evaluated by videomicroscopy. Distribution and organization of the actin-based cytoskeleton, vinculin- and paxillin-containing focal contacts, and beta-catenin-rich intercellular adhesions were determined by immunofluorescence and digital microscopy.


RESULTS
LAT-A induced pronounced but highly reversible rounding of HTM cells, intercellular separation, and disruption of actin filaments. beta-catenin-rich intercellular adherens junctions were particularly sensitive to LAT-A. Vinculin- and paxillin-containing focal contacts were only partially affected and appeared to be more resistant to the drug than the intercellular interactions.


CONCLUSIONS
The increase in outflow facility in the living primate eye induced by LAT-A may be due to the disorganization and disruption of the actin cytoskeleton and its associated cellular adhesions in the trabecular meshwork.
Department of Ophthalmology & Visual Sciences, University of Wisconsin, Madison, WI 53792-3220, USA.
S
S
Cai
X
X
Liu
A
A
Glasser
T
T
Volberg
M
M
Filla
B
B
Geiger
J R
JR
Polansky
P L
PL
Kaufman
D000199:Actins / Q000378:metabolism*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology*; D002448:Cell Adhesion; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D018715:Microscopy, Video; D013844:Thiazoles / Q000494:pharmacology*; D053778:Thiazolidines; D014129:Trabecular Meshwork / Q000166:cytology / Q000187:drug effects* / Q000648:ultrastructure; D015534:Trans-Activators; D016596:Vinculin / Q000378:metabolism; D051176:beta Catenin
D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; C495270:CTNNB1 protein, human; D003598:Cytoskeletal Proteins; D018942:Macrolides; D013844:Thiazoles; D053778:Thiazolidines; D015534:Trans-Activators; D051176:beta Catenin; D016596:Vinculin; C037067:latrunculin A