Transcriptome Analysis on Monocytes from Patients with Neovascular Age-Related Macular Degeneration.

Michelle Grunin,Shira- Hagbi-Levi,Yoav Smith,Batya Rinsky,Itay Chowers

doi:10.1038/srep29046

Abstract

Mononuclear phagocytes (MPs), including monocytes/macrophages, play complex roles in age-related macular degeneration (AMD) pathogenesis. We reported altered gene-expression signature in peripheral blood mononuclear cells from AMD patients, and a chemokine receptor signature on AMD monocytes. To obtain comprehensive understanding of MP involvement, particularly in peripheral circulation in AMD, we performed global gene expression analysis in monocytes. We separated monocytes from treatment-naïve neovascular AMD (nvAMD) patients (n = 14) and age-matched controls (n = 15), and performed microarray and bioinformatics analysis. Quantitative real-time PCR was performed on other sets of nvAMD (n = 25), atrophic AMD (n = 21), and controls (n = 28) for validation. This validated microarray genes (like TMEM176A/B and FOSB) tested, including differences between nvAMD and atrophic AMD. We identified 2,165 differentially-expressed genes (P < 0.05), including 79 genes with log2 fold change ≥1.5 between nvAMD and controls. Functional annotation using DAVID and TANGO demonstrated immune response alterations in AMD monocytes (FDR-P <0.05), validated by randomized data comparison (P < 0.0001). GSEA, ISMARA, and MEME analysis found immune enrichment and specific involved microRNAs. Enrichment of differentially-expressed genes in monocytes was found in retina via SAGE data-mining. These genes were enriched in non-classical vs. classical monocyte subsets (P < 0.05). Therefore, global gene expression analysis in AMD monocytes reveals an altered immune-related signature, further implicating systemic MP activation in AMD.

Highlights

Monocytes can be subdivided into two major subgroups: the CD14++CD16−, or classical monocyte, and the CD14+CD16+, or non-classical subgroup
The CD14+CD16+subgroup has been known as the monocytes that migrate to sites of injury and inflammation or that are active during a disease state[19,21,22,23]
agerelated macular degeneration (AMD), despite being an ocular disorder, may contain, as shown by our results, a systemic inflammatory signature that is found in monocytes from patients with both the atrophic and the neovascular stages

Summary

Introduction

Monocytes can be subdivided into two major subgroups: the CD14++CD16−, or classical monocyte, and the CD14+CD16+, or non-classical subgroup (which can be further subdivided into two groups depending on CD16+expression) These two subgroups have been found to be similar not identical in both mouse and in human, and are identified using different markers- F4/80, Ly6C/G, CD11b, and MHCII in mouse, while CD14 and CD16 along with HLA-DR and CX3CR1 in human[19,20]. Differential expression of additional proteins related to immune responses such as CD46, CD59 and CD200 was reported in white blood cells from AMD patients[17,25]. We wished to investigate for the first time the global gene expression of blood monocytes from patients with nvAMD and age-matched controls via microarray analysis

Methods

Results

Conclusion