Keratinocyte migration in the developing eyelid requires LIMK2.

In vitro studies have identified LIMK2 as a key downstream effector of Rho GTPase-induced changes in cytoskeletal organization. LIMK2 is phosphorylated and activated by Rho associated coiled-coil kinases (ROCKs) in response to a variety of growth factors. The biochemical targets of LIMK2 belong to a family of actin binding proteins that are potent modulators of actin assembly and disassembly. Although numerous studies have suggested that LIMK2 regulates cell morphology and motility, evidence supportive of these functions in vivo has remained elusive. In this study, a knockout mouse was created that abolished LIMK2 biochemical activity resulting in a profound inhibition of epithelial sheet migration during eyelid development. In the absence of LIMK2, nascent eyelid keratinocytes differentiate and acquire a pre-migratory phenotype but the leading cells fail to nucleate filamentous actin and remain immobile causing an eyes open at birth (EOB) phenotype. The failed nucleation of actin was associated with significant reductions in phosphorylated cofilin, a major LIMK2 biochemical substrate and potent modulator of actin dynamics. These results demonstrate that LIMK2 activity is required for keratinocyte migration in the developing eyelid.

Novel class of LIM-kinase 2 inhibitors for the treatment of ocular hypertension and associated glaucoma.

The discovery of a pyrrolopyrimidine class of LIM-kinase 2 (LIMK2) inhibitors is reported. These LIMK2 inhibitors show good potency in enzymatic and cellular assays and good selectivity against ROCK. After topical dosing to the eye in a steroid induced mouse model of ocular hypertension, the compounds reduce intraocular pressure to baseline levels. The compounds also increase outflow facility in a pig eye perfusion assay. These results suggest LIMK2 may be an effective target for treating ocular hypertension and associated glaucoma.