GF134 Sigma-AldrichPigment Epithelium Derived Factor Protein, Recombinant human

Our earlier work has shown that repeated administration of classical neuroleptic drugs gives rise to structural alterations in target regions of the mesolimbic pathway, most notably, nucleus accumbens. Such changes could be responsible for the efficacious or motor side effects associated with these drugs. Growth factors such as brain-derived neurotrophic factor (BDNF) provide trophic support for dopaminergic neurons during development and mediate synaptic and morphological plasticity in numerous regions of the adult CNS. The present study examines whether BDNF is altered in the mesolimbic pathway by classical neuroleptic treatment. Animals were administered haloperidol, 0.5 mg/kg, or vehicle, i.p., for either 3 or 21 days, followed by transcardiac perfusion with fixative. Three days of haloperidol administration dramatically decreased BDNF immunostaining in the neurons and fibers of the prefrontal cortex, hippocampus (dentate gyrus, CA2, and CA3), extended amygdala, and ventral tegmental area. BDNF-immunoreactive fibers virtually disappeared from the neostriatum and nucleus accumbens. Subchronic (21 days) treatment led to a rebound in BDNF immunoreactivity in most cell bodies but not in fibers. These results show that blockade of dopaminergic receptors with haloperidol rapidly downregulates BDNF in reward and emotional centers of the brain. Such rapid inactivation and subsequent reappearance of BDNF immunoreactivity could affect synaptic strength and plasticity and therefore be important preliminary steps in the cascade of neuronal events that lead to the efficacious or detrimental side effects of classical neuroleptic drugs.

PURPOSE: To localize pigment epithelium-derived factor (PEDF) in developing and adult human ocular tissues. METHODS: PEDF was localized in fetal and adult eyes by immunofluorescence with a polyclonal antibody (pAb) against amino acids 327-343 of PEDF, or a monoclonal antibody (mAb) against the C-terminal 155 amino acids of PEDF. Specificity of the antibodies was documented by Western blotting. PEDF mRNA was localized in adult retina by in situ hybridization. RESULTS: In developing retinas (7.4 to 21.5 fetal weeks, Fwks), pAb anti-PEDF labeled retinal pigment epithelium (RPE) granules, developing cones, some neuroblasts and many cells in the ganglion cell layer (GCL). In adult retinas, pAb anti-PEDF labeled rod and cone cytoplasm and nuclei of rods but not cones. Cells in the INL and GCL, choroid, corneal epithelium and endothelium, and ciliary body were also pAb PEDF-positive. Preadsorption of pAb anti-PEDF with the immunizing peptide blocked specific labeling in retina and other tissues, except for photoreceptor outer segments. In agreement with the immunolocalization with pAb anti-PEDF, in situ hybridization revealed PEDF mRNA in the RPE, photoreceptors, inner nuclear layer cells and ganglion cells in adult retina. In developing retinas 18 Fwks and older, and in adult retinas, mAb anti-PEDF labeled the interphotoreceptor matrix (IPM). Western blots of retina, cornea, and ciliary body/iris with pAb anti-PEDF produced several bands at about 46 kDa. With mAb anti-PEDF, retina produced one band at about 46 kDa; cornea and ciliary body/iris had several bands at about 46 kDa. CONCLUSIONS: PEDF, originally reported as a product of RPE cells, is present in photoreceptors and inner retinal cell types in developing and adult human eyes. Photoreceptors and RPE may secrete PEDF into the IPM.

Pigment epithelium-derived factor (PEDF) is a member of the serine protease inhibitor superfamily produced by retinal pigment epithelial cells in the developing and adult retina. In vitro, it induces neuronal differentiation of retinoblastoma cells and promotes survival of cerebellar granule neurons. The pedf gene is closely linked to an autosomal-dominant locus for retinitis pigmentosa, suggesting that PEDF could be a survival factor for photoreceptors. We have investigated this possibility by injecting PEDF into the eyes of homozygous retinal degeneration (rd) and retinal degeneration slow (rds) mice, two mutants displaying apoptotic photoreceptor loss. This procedure resulted in a transient delay of photoreceptor loss in the rd mouse and a reduction in apoptotic photoreceptor profiles in the rds mouse. We conclude that PEDF can act as a survival-promoting factor for photoreceptors in vivo and could potentially be useful for the treatment of photoreceptor diseases.