Modulated expression of secreted Frizzled-related proteins in human retinal degeneration

Inherited retinal degenerations such as retinitis pigmentosa (RP) are chara cterized by progressive loss of photoreceptors, apparently by apoptosis, an d our recent report of increased secreted Frizzed-related protein-2 (SFRP2) in RP retinas suggests altered Wnt signalling may be a component of the de generative process. The present study shows that levels of SFRP1, SFRP3 and SFRP5 mRNAs are also abnormal in RP, giving rise to idiosyncratic expressi on patterns. In highly degenerative retinas, the SFRP proteins localize mai nly to the inner limiting membrane, but in a well-preserved retina SFRP1 an d SFRP5 are notably localized to the surviving photoreceptors. Together wit h increased c-jun mRNA expression in all cases examined, these results supp ort the notion that disruptions of Wnt network signalling are involved in r etinal neurodegeneration. NeuroReport 11:3963-3967 (C) 2000 Lippincott Will iams & Wilkins.