title: Ras homolog enriched in the brain is linked to retinal ganglion cell apoptosis after light injury in rats.
abstract: Ras homolog enriched in the brain (Rheb) is a small GTPase of the Ras family. It has been confirmed that Rheb activation not only regulates cell growth and migration but also induces neuron apoptosis after toxic stimuli. However, the function of Rheb in the retina is still not fully understood. To find out whether Rheb was involved in retinal neuron death, the expression profile of Rheb in light-damaged retinal ganglion cells (RGCs) of adult rats was investigated. Western blotting showed the expression of Rheb was significantly upregulated in the injured retina. Rheb was mainly detected in apoptotic RGCs by using double immunofluorescent staining. Active caspase-3 was upregulated and co-labeled with Rheb. Meanwhile, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that Rheb-positive RGCs underwent apoptosis after light exposure, which suggested that Rheb might be relevant to RGC apoptosis following phototoxicity. Furthermore, Western blotting and immunofluorescence showed that the expression profiles of CyclinD1 and cyclin-dependent kinase 4 (CDK4) were parallel with that of Rheb in a time-space dependent manner. Based on this study, it is speculated that Rheb might play an important role in physiological and pathological process in light-induced retina damage, which might provide a potential therapeutic avenue of retinal degeneration.
authors.affiliation: Department of Ophthalmology and Vision Sciences and Key Laboratory of Myopia of State Health Ministry, Eye and ENT Hospital, Shanghai Medical College, Fudan University, No.83 Fenyang Road, Shanghai, People's Republic of China.
authors.forename: Qinmeng
authors.initials: Q
authors.lastname: Shu
authors.forename: Yue
authors.initials: Y
authors.lastname: Xu
authors.forename: Hong
authors.initials: H
authors.lastname: Zhuang
authors.forename: Jiawen
authors.initials: J
authors.lastname: Fan
authors.forename: Zhongcui
authors.initials: Z
authors.lastname: Sun
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.forename: Gezhi
authors.initials: G
authors.lastname: Xu
mesh_terms: D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4 / Q000235:genetics / Q000378:metabolism; D008027:Light / Q000009:adverse effects*; D008297:Male; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D000076205:Ras Homolog Enriched in Brain Protein; D051381:Rats; D017207:Rats, Sprague-Dawley; D012162:Retinal Degeneration / Q000209:etiology / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000378:metabolism* / Q000528:radiation effects
chemical_list: D009479:Neuropeptides; D000076205:Ras Homolog Enriched in Brain Protein; C490213:Rheb protein, mouse; D019938:Cyclin D1; C495902:Cdk4 protein, mouse; D051358:Cyclin-Dependent Kinase 4; D053148:Caspase 3; D020559:Monomeric GTP-Binding Proteins