AAV2-PDE6B restores retinal structure and function in the retinal degeneration 10 mouse model of retinitis pigmentosa by promoting phototransduction and inhibiting apoptosis

Retinitis pigmentosa is a group of inherited diseases that lead to retinal degeneration and photoreceptor cell death.However,there is no effective treatment for retinitis pigmentosa caused by PDE6B mutation.Adeno-associated virus(AAV)-mediated gene therapy is a promising strategy for treating retinitis pigmentosa.The aim of this study was to explore the molecular mechanisms by which AAV2-PDE6B rescues retinal function.To do this,we injected retinal degeneration 10(rd10)mice subretinally with AAV2-PDE6B and assessed the therapeutic effects on retinal function and structure using dark-and light-adapted electroretinogram,optical coherence tomography,and immunofluorescence.Data-independent acquisition-mass spectrometry-based proteomic analysis was conducted to investigate protein expression levels and pathway enrichment,and the results from this analysis were verified by real-time polymerase chain reaction and western blotting.AAV2-PDE6B injection significantly upregulated PDE6βexpression,preserved electroretinogram responses,and preserved outer nuclear layer thickness in rd10 mice.Differentially expressed proteins between wild-type and rd10 mice were closely related to visual perception,and treating rd10 mice with AAV2-PDE6B restored differentially expressed protein expression to levels similar to those seen in wild-type mice.Kyoto Encyclopedia of Genes and Genome analysis showed that the differentially expressed proteins whose expression was most significantly altered by AAV2-PDE6B injection were enriched in phototransduction pathways.Furthermore,the phototransductionrelated proteins Pde6α,Rom1,Rho,Aldh1a1,and Rbp1 exhibited opposite expression patterns in rd10 mice with or without AAV2-PDE6B treatment.Finally,Bax/Bcl-2,p-ERK/ERK,and p-c-Fos/c-Fos expression levels decreased in rd10 mice following AAV2-PDE6B treatment.Our data suggest that AAV2-PDE6B-mediated gene therapy promotes phototransduction and inhibits apoptosis by inhibiting the ERK signaling pathway and upregulating Bcl-2/Bax expression in retinitis pigmentosa.

Identification of Age-associated Proteins and Functional Alterations in Human Retinal Pigment Epithelium

Retinal pigment epithelium(RPE)has essential functions,such as nourishing and supporting the neural retina,and is of vital importance in the pathogenesis of age-related retinal degeneration.However,the exact molecular changes of RPE during aging remain poorly understood.Here,we isolated human primary RPE(h RPE)cells from 18 eye donors distributed over a wide age range(10–67 years old).A quantitative proteomic analysis was performed to analyze changes in their intracellular and secreted proteins.Age-group related subtypes and age-associated proteins were revealed and potential age-associated mechanisms were validated in ARPE-19 and h RPE cells.The results of proteomic data analysis and verifications suggest that RNF123-and RNF149-related protein ubiquitination plays an important role in protecting h RPE cells from oxidative damage during aging.In older h RPE cells,apoptotic signaling-related pathways were up-regulated,and endoplasmic reticulum organization was down-regulated both in the intracellular and secreted proteomes.Our work paints a detailed molecular picture of h RPE cells during the aging process and provides new insights into the molecular characteristics of RPE during aging and under other related clinical retinal conditions.