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Abstract #59294 Published in IGR 16-3
Neuroprotection of a novel cyclopeptide C*HSDGIC* from the cyclization of PACAP (1-5) in cellular and rodent models of retinal ganglion cell apoptosis
Cheng H; Ding Y; Yu R; Chen J; Wu CPLoS ONE 2014; 9: e108090
PURPOSE: To investigate the protective effects of a novel cyclopeptide C*HSDGIC* (CHC) from the cyclization of Pituitary adenylate cyclase-activating polypeptide (PACAP) (1-5) in cellular and rodent models of retinal ganglion cell apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: Double-labeling immunohistochemistry was used to detect the expression of Thy-1 and PACAP receptor type 1 in a retinal ganglion cell line RGC-5. The apoptosis of RGC-5 cells was induced by 0.02 J/cm(2) Ultraviolet B irradiation. MTT assay, flow cytometry, fluorescence microscopy were used to investigate the viability, the level of reactive oxygen species (ROS) and apoptosis of RGC-5 cells respectively. CHC attenuated apoptotic cell death induced by Ultraviolet B irradiation and inhibited the excessive generation of ROS. Moreover, CHC treatment resulted in decreased expression of Bax and concomitant increase of Bcl-2, as was revealed by western-blot analysis. The in vivo apoptosis of retinal ganglion cells was induced by injecting 50 mM N-methyl-D-aspartate (NMDA) (100 nmol in a 2 µL saline solution) intravitreally, and different dosages of CHC were administered. At day 7, rats in CHC+ NMDA-treated groups showed obvious aversion to light when compared to NMDA rats. Electroretinogram recordings revealed a marked decrease in the amplitudes of a-wave, b-wave, and photopic negative response due to NMDA damage. In retina receiving intravitreal NMDA and CHC co-treatment, these values were significantly increased. CHC treatment also resulted in less NMDA-induced cell loss and a decrease in the proportion of dUTP end-labeling-positive cells in ganglion cell line. CONCLUSIONS: C*HSDGIC*, a novel cyclopeptide from PACAP (1-5) attenuates apoptosis in RGC-5 cells and inhibits NMDA-induced retinal neuronal death. The beneficial effects may occur via the mitochondria pathway. PACAP derivatives like CHC may serve as a promising candidate for neuroprotection in glaucoma.
Department of Ophthalmology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Full articleClassification:
11.8 Neuroprotection (Part of: 11 Medical treatment)
11.14 Investigational drugs; pharmacological experiments (Part of: 11 Medical treatment)
5.1 Rodent (Part of: 5 Experimental glaucoma; animal models)
3.6 Cellular biology (Part of: 3 Laboratory methods)