Arrest Of Degeneration Research Articles

Repeated Topical Administration of 3 nm Cerium Oxide Nanoparticles Reverts Disease Atrophic Phenotype and Arrests Neovascular Degeneration in AMD Mouse Models.

Increased oxidative stress in the retina and retinal pigment epithelium is implicated in age-related macular degeneration (AMD). Antioxidant cerium oxide nanoparticles (CeO2NPs) have been used to treat degenerative retinal pathologies in animal models, although their delivery route is not ideal for chronic patient treatment. In this work, we prepared a formulation for ocular topical delivery that contains small (3 nm), nonaggregated biocompatible CeO2NPs. In vitro results indicate the biocompatible and protective character of the CeO2NPs, reducing oxidative stress in ARPE19 cells and inhibiting neovascularization related to pathological angiogenesis in both HUVEC and in in vitro models of neovascular growth. In the in vivo experiments, we observed the capacity of CeO2NPs to reach the retina after topical delivery and a subsequent reversion of the altered retinal transcriptome of the retinal degenerative mouse model DKOrd8 toward that of healthy control mice, together with signs of decreased inflammation and arrest of degeneration. Furthermore, CeO2NP eye drops' treatment reduced laser-induced choroidal neovascular lesions in mice by lowering VEGF and increasing PEDF levels. These results indicate that CeO2NP eye drops are a beneficial antioxidant and neuroprotective treatment for both dry and wet forms of AMD disease.

The effect of irradiation on cell degeneration among developing neurones in Xenopus laevis.

In the development of the vertebrate nervous system not all the neuroblasts complete their development into neurones. In the lumbar ventral horns of the larvae of Xenopus laevis, the number of viable and degenerating cells has been counted throughout development. Given an estimate of the duration of cell death, the total number of cells which degenerate can be calculated; for every cell which finally differentiates, eight or nine die during development. The death rate of cells in the ventral horns can be reduced or abolished by X rays at a dosage of 80–160 r. This arrest may persist for nearly three weeks with relatively young tadpoles, but for only a few days with older animals. When larvae are irradiated near the maximal period of normal degeneration, the arrest of degeneration is evident within a few hours after treatment. The effect is thus shown to be more than a secondary consequence of a general halt in development.