Effect of VCP modulators on gene expression profiles of retinal ganglion cells in an acute injury mouse model

Abstract

In glaucoma, retinal ganglion cells are damaged, leading to the progressive constriction of the visual field. We have previously shown that the valosin-containing protein (VCP) modulators, Kyoto University Substance (KUS)121 and KUS187, prevent the death of retinal ganglion cells in animal models of glaucoma, including the one generated by N-methyl-D-aspartate (NMDA)-induced neurotoxicity. KUSs appeared to avert endoplasmic reticulum (ER) stress by maintaining ATP levels, resulting in the protection of ganglion cells from cell death. To further elucidate the protective mechanisms of KUSs, we examined gene expression profiles in affected ganglion cells. We first injected KUS-treated mice with NMDA and then isolated the affected retinal ganglion cells using fluorescence-activated cell sorting. Gene expression in the cells was quantified using a next-generation sequencer. Resultantly, we found that KUS121 upregulated several genes involved in energy metabolism. In addition, we observed the upregulation of Zfp667, which has been reported to suppress apoptosis-related genes and prevent cell death. These results further support the suitability of KUS121 as a therapeutic drug in protecting retinal ganglion cells in ophthalmic disorders, such as glaucoma.

Hop flower extracts mitigate retinal ganglion cell degeneration in a glaucoma mouse model

“…In addition, there is a possibility that hop flower extracts attenuate retinal ganglion cell degeneration through mechanisms other than Aβ reduction, which we could not identify in this study. In fact, the mechanisms underlying glaucoma progression are still not fully understood and a considerable number of genes have been implicated in the pathogenesis of glaucoma 24 .…”

Involvement of endothelins in neuroprotection of valosin-containing protein modulators against retinal ganglion cell damage

“…All protocols were approved by the Institutional Review Board of the Kyoto University Graduate School of Medicine (MedKyo 12245, 13221, 14213, 15531, 16501). B6.Cg-Tg (Thy 1-CFP) 23 Jrs/J mice, which express cyan fluorescent protein (CFP) in RGCs 26 , were obtained from the Jackson Laboratory (Bar Harbor, ME, USA) and were used for RGC collection by FACS as previously reported 10 . Wild-type mice (C57/BL6), which share a genetic background with Thy1-CFP mice, were purchased from Japan SLC Inc (Shizuoka, Japan).…”

“…The NMDA-saline group mice orally received a vehicle [5% Cremophor EL (Sigma) in phosphate-buffered saline (PBS)], instead of KUSs, for 7 days as a control. Before intravitreous NMDA injection, the mice were anesthetized by intraperitoneal injection of pentobarbital (50 mg/kg) and mydriasis with tropicamide and phenylephrine eye drops (0.5% each) 10 . The retinas were collected unilaterally from each mouse and analyzed.…”

“…The results of RNA-sequencing, which have been reported previously 10 , were mapped to a reference sequence (mouse mm10, USCS genome browser), after which the expression levels were calculated and the expression value normalized by quantile normalization methods as previously reported 10 . Expression changes among conditions were analyzed using ANOVA.…”

“…KUSs are considered to prevent cell death by preventing intracellular ATP decrease, but the mechanism of cell protection by KUSs has not been fully elucidated. We have previously shown that the expression of various genes in retinal ganglion cells (RGCs), isolated by fluorescence-activated cell sorting, was altered by KUS treatment in a model of N-methyl- d -aspartate (NMDA)-induced acute retinal ganglion cell death 10 . In the previous study, 255 genes, whose expression varied significantly between groups according to analysis of variance (ANOVA) at a 1% level of significance, were analyzed.…”