Abstract
Purpose :
Pathological proliferation of blood vessels is a major cause of blindness and is a hallmark of retinopathy of prematurity (ROP). We and others have reported that photoreceptors can signal for pathological blood vessel growth through inflammatory factors. However, the underlying molecular mechanisms through which photoreceptor cells control retinal angiogenesis in ROP is still unknown. We aim to investigate the signaling pathways in photoreceptor cells that control retinal angiogenesis via suppressor of cytokine signaling 3 (SOCS3) using single-cell RNA sequencing (scRNAseq).
Methods :
Rod-specific Socs3 loss-of-function (Socs3 cKO) and gain-of-function (Socs3 cOE) mice were generated by breeding rhodopsin improved Cre mice (Rho-iCre) with floxed mice for Socs3 knockout (Socs3f/f) and overexpression (Socs3OEf/f), respectively. The oxygen-induced retinopathy (OIR) model was used as a mouse model of ROP. Normal and OIR retinal cells were processed for scRNAseq library construction using 10x Genomics and sequenced using NextSeq500. Seurat 4.0 was used to analyze sequencing read counts. PCA analysis was performed for dimension reduction. Cell clusters were visualized in reduced dimensions of t-distributed stochastic neighbor embedding (tSNE). Differentially expressed genes (DEGs) were subjected to Gene Ontology (GO) analysis using cluster profiler and gene-set enrichment.
Results :
DEGs analysis showed that 76 DEGs (36 upregulated, 40 downregulated) were detected in rod cells in OIR retinas vs normal controls. 144 DEGs (90 upregulated, 54 downregulated) were detected in rod cells in SOCS3 deficient retinas with OIR vs wild type OIR retinas. Gene enrichment assay of DEGs using GSEA4.1.0 showed that genes related to mitochondrial function and metabolic pathways, such as ATP5MC3, MT-CYB, MT-ND2, MT-ATP8, were enriched in Socs3 cKO retinas under hypoxic conditions. In addition, key pathways involved in phototransduction, cholinergic signaling, and chemokine signaling were significantly changed in OIR retinas.
Conclusions :
Our data suggests that photoreceptor SOCS3 may control neovascularization through modulating photoreceptor mitochondrial function and metabolism.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.