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A Protocol to Evaluate and Quantify Retinal Pigmented Epithelium Pathologies in Mouse Models of Age-Related Macular Degeneration
Published on: March 10, 2023
Transcriptome Analysis of Retinal and Choroidal Pathologies in Aged BALB/c Mice Following Systemic Neonatal Murine
Xinyan Zhang1,2, Jinxian Xu1,2, Brendan Marshall1
1Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA.
Abstract:
Our previous studies have shown that systemic neonatal murine cytomegalovirus (MCMV) infection of BALB/c mice spread to the eye with subsequent establishment of latency in choroid/RPE. In this study, RNA sequencing (RNA-Seq) analysis was used to determine the molecular genetic changes and pathways affected by ocular MCMV latency. MCMV (50 pfu per mouse) or medium as control were injected intra-peritoneally (i.p.) into BALB/c mice at <3 days after birth. At 18 months post injection, the mice were euthanized, and the eyes were collected and prepared for RNA-Seq. Compared to three uninfected control eyes, we identified 321 differentially expressed genes (DEGs) in six infected eyes. Using the QIAGEN Ingenuity Pathway Analysis (QIAGEN IPA), we identified 17 affected canonical pathways, 10 of which function in neuroretinal signaling, with the majority of DEGs being downregulated, while 7 pathways function in upregulated immune/inflammatory responses. Retinal and epithelial cell death pathways involving both apoptosis and necroptosis were also activated. MCMV ocular latency is associated with upregulation of immune and inflammatory responses and downregulation of multiple neuroretinal signaling pathways. Cell death signaling pathways are also activated and contribute to the degeneration of photoreceptors, RPE, and choroidal capillaries.
Insights
Neonatal murine cytomegalovirus (MCMV) infection establishes eye latency, altering gene expression. Ocular MCMV latency upregulates immune responses and downregulates neuroretinal pathways, leading to cell death and degeneration.
Area of Science:
- Ophthalmology
- Virology
- Immunology
Background:
- Systemic neonatal murine cytomegalovirus (MCMV) infection in BALB/c mice leads to ocular latency.
- Previous studies established MCMV latency in the choroid/retinal pigment epithelium (RPE) of the eye.
Purpose of the Study:
- To investigate the molecular genetic changes and affected pathways during ocular MCMV latency.
- To identify differentially expressed genes (DEGs) and signaling pathways impacted by latent MCMV infection in the eye.
Main Methods:
- RNA sequencing (RNA-Seq) analysis of ocular tissues from MCMV-infected and control mice at 18 months post-infection.
- Bioinformatic analysis using QIAGEN Ingenuity Pathway Analysis (IPA) to identify affected canonical pathways.
Main Results:
- Identified 321 differentially expressed genes (DEGs) in eyes with latent MCMV infection.
- Found 17 affected canonical pathways: 10 downregulated neuroretinal signaling pathways and 7 upregulated immune/inflammatory response pathways.
- Activated retinal and epithelial cell death pathways (apoptosis and necroptosis) were observed.
Conclusions:
- Ocular MCMV latency is characterized by increased immune and inflammatory responses.
- Latent MCMV infection downregulates crucial neuroretinal signaling pathways.
- Activated cell death pathways contribute to the degeneration of photoreceptors, RPE, and choroidal capillaries.
