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Abstract #91857 Published in IGR 21-4
Neuroprotective effect of the somatostatin receptor 5 agonist L-817,818 on retinal ganglion cells in experimental glaucoma
Zhang Y; Wu N; Li Q; Hu X; Wang L; Sun JG; Wang Z; Sun XHExperimental Eye Research 2021; 204: 108449
Somatostatin plays important roles in modulating neuronal functions by activating the five specific G-protein coupled receptors (sst1-sst5). Previous studies have demonstrated that sst5 were expressed in retinal ganglion cells (RGCs) and sst5 agonist attenuated the α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid-induced retinal neurotoxicity. In this study, we investigated effects and underlying mechanisms of the sst5 agonist L-817,818 on RGC injury induced by elevated intraocular pressure (COH) in experimental glaucoma. Our results showed that intraperitoneal administration of L-817,818 significantly reduced RGC loss and decreased the number of terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL)-positive RGCs in COH retinas, suggesting that L-817,818 may attenuate RGC apoptosis. Consistently, in COH retinas with L-817,818 administration, both the down-regulated mRNA and protein levels of anti-apoptotic Bcl-2 and the up-regulated mRNA and protein levels of pro-apoptotic Bax were partially reversed. L-817,818 administration downregulated the expression of apoptosis-related proteins caspase-9 and caspase-3 in COH retinas. In addition, L-817,818 administration reduced the concentrations of reactive oxygen species/reactive nitrogen species and malondialdehyde, and ameliorated the functions of mitochondrial respiratory chain complex (MRCC). Our results imply that administration of the sst5 agonist L-817,818 reduces RGC loss in COH rats through decreasing RGC apoptosis, which is mediated by regulating Bcl-2/Bax balance, reducing oxidative stress and rescuing activities of MRCC. Activation of sst5 may provide neuroprotective roles for RGCs in glaucoma.
Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, NHC Key Laboratory of Myopia, Shanghai Key Laboratory of Visual Impairment and Restoration, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China.
Full articleClassification:
3.7 Biochemistry (Part of: 3 Laboratory methods)
5.1 Rodent (Part of: 5 Experimental glaucoma; animal models)
11.8 Neuroprotection (Part of: 11 Medical treatment)
11.14 Investigational drugs; pharmacological experiments (Part of: 11 Medical treatment)