Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Nov 20;9(11):1154.
doi: 10.3390/antiox9111154.

Expression of Pro-Angiogenic Markers Is Enhanced by Blue Light in Human RPE Cells

Concetta Scimone  1   2 , Simona Alibrandi  1   3 , Sergio Zaccaria Scalinci  4 , Edoardo Trovato Battagliola  4 , Rosalia D'Angelo  1 , Antonina Sidoti  1 , Luigi Donato  1   2
Affiliations

Expression of Pro-Angiogenic Markers Is Enhanced by Blue Light in Human RPE Cells

Concetta Scimone et al. Antioxidants (Basel). .

Abstract

Inherited retinal dystrophies are characterized by photoreceptor death. Oxidative stress usually occurs, increasing vision loss, and oxidative damage is often reported in retinitis pigmentosa (RP). More than 300 genes have been reported as RP causing. In contrast, choroidal neovascularization (CNV) only occasionally develops in the late stages of RP. We herein study the regulation of RP causative genes that are likely linked to CNV onset under oxidative conditions. We studied how the endogenous adduct N-retinylidene-N-retinylethanolamine (A2E) affects the expression of angiogenic markers in human retinal pigment epithelium (H-RPE) cells and a possible correlation with RP-causing genes. H-RPE cells were exposed to A2E and blue light for 3 and 6h. By transcriptome analysis, genes differentially expressed between A2E-treated cells and untreated ones were detected. The quantification of differential gene expression was performed by the Limma R package. Enrichment pathway analysis by the FunRich tool and gene prioritization by ToppGene allowed us to identify dysregulated genes involved in angiogenesis and linked to RP development. Two RP causative genes, AHR and ROM1, can be associated with an increased risk of CNV development. Genetic analysis of RP patients affected by CNV will confirm this hypothesis.

Keywords: angiogenesis; biomarkers; choroidal neovascularization; oxidative stress; retinitis pigmentosa.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Methylthiazolyldiphenyl-tetrazolium bromide (MTT)-viability assay results. N-retinylidene-N-retinylethanolamine (A2E) had a cytotoxic effect on human retinal pigment epithelium (H-RPE) cells in a time-dependent manner. The viability of untreated (0 h) H-RPE cells and 3, 6 and 9 h A2E-exposed H-RPE cells is expressed as a percentage, as the mean ± SD (n = 3). Statistical significance was assessed by multiple t-tests (p-values < 0.05). Due to markedly decreased cell viability at 9 h with A2E, this time point was excluded in further analysis.
Figure 2
Figure 2
Differentially Expressed Genes (DEGs) in A2E-treated RPE cells. The histogram shows DEGs detected in RPE cells treated with A2E when compared to untreated cultures. Values are expressed in percentage. For each time point considered, blue bars indicate the down-expressed genes, while red ones refer to up-regulated genes. Both A2E-treated cells and control H-RPE cells were exposed to a blue light period.
Figure 3
Figure 3
Angiogenesis-related genes dysregulated in A2E-treated H-RPE cells. (a) The Venn diagram reports the number of angiogenesis-related DEGs, for each time point (intersections). (b) Pair-comparison highlighting the percentage of DEGs between time-point pairs.
Figure 4
Figure 4
Real-time PCR results and correlation analysis. (a) The bar charts show a comparison between expression values (as log2 fold change (FC)) observed by qRT-PCR and RNA sequencing. Represented values are the average of the three replicates. (b,c) Correlation analysis between log2 FC observed values by RNAseq (x-axis) and qRT-PCR (y-axis) at the first (b) and at the second (c) time point.
Figure 5
Figure 5
Enriched genes in biological pathways related to angiogenesis. Each biological pathway is considered both 3 and 6 h after A2E treatment. Enrichment percentage and the Bonferroni-adjusted p-value are reported.
See this image and copyright information in PMC

References

    1. Fuhrmann S., Zou C., Levine E.M. Retinal pigment epithelium development, plasticity, and tissue homeostasis. Exp. Eye Res. 2014;123:141–150. doi: 10.1016/j.exer.2013.09.003. - DOI - PMC - PubMed
    1. Muniz A., Betts B.S., Trevino A.R., Buddavarapu K., Roman R., Ma J.X., Tsin A.T. Evidence for two retinoid cycles in the cone-dominated chicken eye. Biochemistry. 2009;48:6854–6863. doi: 10.1021/bi9002937. - DOI - PMC - PubMed
    1. Fields M.A., Del Priore L.V., Adelman R.A., Rizzolo L.J. Interactions of the choroid, Bruch’s membrane, retinal pigment epithelium, and neurosensory retina collaborate to form the outer blood-retinal-barrier. Prog. Retin. Eye Res. 2020;76:100803. doi: 10.1016/j.preteyeres.2019.100803. - DOI - PubMed
    1. Hellinen L., Sato K., Reinisalo M., Kidron H., Rilla K., Tachikawa M., Uchida Y., Terasaki T., Urtti A. Quantitative Protein Expression in the Human Retinal Pigment Epithelium: Comparison Between Apical and Basolateral Plasma Membranes with Emphasis on Transporters. Investig. Ophthalmol. Vis. Sci. 2019;60:5022–5034. doi: 10.1167/iovs.19-27328. - DOI - PubMed
    1. Reichhart N., Strauss O. Ion channels and transporters of the retinal pigment epithelium. Exp. Eye Res. 2014;126:27–37. doi: 10.1016/j.exer.2014.05.005. - DOI - PubMed

LinkOut - more resources