Single-cell RNA Analysis of Peripheral Blood Mononuclear Cells In a Mouse Model of Retinitis Pigmentosa

Abstract

Purpose : We previously reported that circulating inflammatory monocytes promote cone cell death in a mouse model of retinitis pigmentosa (RP). However, the molecular characteristics of these inflammatory monocytes and other peripheral immune cells have not been fully elucidated. To identify the pathological peripheral immune cell subsets in RP, we here performed single cell RNA analysis using peripheral blood mononuclear cells (PBMCs) from a mouse model of RP.

Methods : Peripheral blood was taken from rd10 mouse (n=1), a spontaneous RP model with Pde6b mutation, and C57BL/6 WT mouse by cardiac puncture at 6 weeks of age. PBMCs were isolated with Histopaque 1083. Single-cell suspensions were processed through the 10X Genomics Chromium Controller following the protocol outlined in the Chromium Next GEM Single Cell 5’ Reagent Kits v2 User Guide. Libraries were pooled and sequenced on an Illumina Novaseq6000SP platform. The combined gene expression matrix generated in Cell Ranger was analyzed using the R package Seurat v4.3.0. Dimensionality reduction was performed by UMAP and the ratio of each immune cell cluster was compared between Rd10 mouse and WT mouse with Chi-square test.

Results : A subset expressing X-related genes was significantly increased in Rd10 mouse compared with WT mouse at 6.99% and 0.06% respectively (p<0.0001). The cluster was accompanied by the expression of inflammatory monocytes related genes such as Lyz2 and Ifitm3.

Conclusions : A novel peripheral immune subset was significantly increased in PBMC of 6-week-old rd10 mouse, suggesting their involvement in cone cell degeneration.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.