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Efficacy of Rho-kinase Inhibition in Promoting Cell Survival and Reducing Reactive Gliosis in the Rodent Retina

2009; Cadmus Press; Volume: 50; Issue: 1 Linguagem: Inglês

10.1167/iovs.08-1973

1552-5783

Aysegu ̈l Tura, Frank Schuettauf, Philippe P. Monnier, Karl Ulrich Bartz‐Schmidt, Sigrid Henke‐Fahle,

Glaucoma and retinal disorders

purpose. To analyze the outcomes of Rho-kinase (ROCK) inhibition on retinal cell survival and glial reactivity under adverse conditions. methods. Organotypic cultures of mouse retinas were incubated with the specific ROCK-inhibitor H-1152P for 24 to 48 hours under serum deprivation. Cell damage was determined by ethidium homodimer-1 uptake and caspase-3 cleavage. Immunohistochemistry and Western blot were performed to detect reactive gliosis and to confirm the specificity of H-1152P. The cytokine profile of the culture medium was analyzed using a membrane-based array. H-1152P was administered intravitreally into rats before optic nerve crush (ONC) and the extent of apoptosis and reactive gliosis was determined after 7 days. results. Cell damage in cultured retinas was significantly reduced in response to 1 μM H-1152P, particularly in the ganglion cell layer. This was associated with a decrease in the levels of glial fibrillary acidic protein (GFAP) isoforms and the number of reactive astrocytes, Müller cells, and microglia. The release of proinflammatory cytokines including TNF-alpha, interferon-gamma, and IL-6 was also reduced, which likely contributed to the significantly lower toxicity of the conditioned media collected from retinas incubated with H-1152P. H-1152P (1 μM) suppressed the ROCK-dependent phosphorylation of adducin without a considerable interference with the protein kinase A/C-mediated phosphorylation events, indicating the specificity of the inhibitor for ROCK. H-1152P also resulted in a significant decrease in the extent of apoptosis and reactive gliosis after ONC. conclusions. These results demonstrate the neuroprotective effect of H-1152P-mediated ROCK-inhibition on retinal cells under stress, which may rely partly on the attenuation of glial cell reactivity.