Marine sponges are a rich source of bioactive metabolites that can potentially be used as lead compounds to treat various human diseases. Due to the difficulty in obtaining a steady supply of such metabolites, few of these compounds have reached the clinical trials stage. Sponge sea ranching is one of the most promising methods to overcome this bsupply problemQ. The Red Sea sponge Negombata mag...

To test different models of myofibrillogenesis, we followed live cells expressing Green Fluorescent Proteins ligated to either actin or alpha-actinin and analyzed stress fibers, premyofibrils, and myofibrils in quail myotube cultures. Actin filaments in the three types of fibers were compared by analyzing the effects of Latrunculin-A (Lat-A), a monomeric actin binding macrolide drug (M.W. = 422...

The actin cytoskeleton is absolutely required for pollen germination and tube growth, but little is known about the regulation of actin polymer concentrations or dynamics in pollen. Here, we report that latrunculin B (LATB), a potent inhibitor of actin polymerization, had effects on pollen that were distinct from those of cytochalasin D. The equilibrium dissociation constant measured for LATB b...

To determine the mechanism of latrunculin B (LAT-B)-induced decrease in outflow resistance and the effect of LAT-B on the cornea, structural changes of the trabecular meshwork (TM) and the corneal endothelium following LAT-B were studied in the live monkey eye. LAT-B (0.5 microM) and vehicle were administered by anterior chamber exchange and infusion with cationized and non-cationized gold solu...

PURPOSE To determine the impact of substratum stiffness and latrunculin-B (Lat-B), on the expression of several matrix proteins that are associated with glaucoma. METHODS Human trabecular meshwork (HTM) cells were cultured on hydrogels possessing stiffness values mimicking those found in normal (5 kPa) and glaucomatous meshworks (75 kPa), or tissue culture polystyrene (TCP; >1 GPa). Cells wer...

PURPOSE To evaluate the safety, tolerability, and intraocular pressure (IOP)-lowering effect of Latrunculin-B (Lat-B), a marine macrolide that disrupts the actin cytoskeleton, in patients with ocular hypertension (OHT) or early primary open-angle glaucoma (POAG). METHODS In this Phase I, multicenter, double-masked, randomized, placebo-controlled, ascending-dose study, subjects with bilateral ...

The rice blast fungus Magnaporthe oryzae infects plants with a specialized cell called an appressorium, which uses turgor to drive a rigid penetration peg through the rice leaf cuticle. Here, we show that NADPH oxidases (Nox) are necessary for septin-mediated reorientation of the F-actin cytoskeleton to facilitate cuticle rupture and plant cell invasion. We report that the Nox2-NoxR complex spa...