Purchase this article with an account.
Sonali R Nashine, Deepika Malik, Cristina M Kenney, Baruch Kuppermann; Differential expression of IL-1β in human retinal H and J transmitochondrial cybrids after UV treatment. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):832.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Age-related macular degeneration (AMD), one of the leading causes of vision loss in older individuals of developed countries, is known to be associated with certain mitochondrial (mt) DNA haplogroups. While the H mtDNA haplogroup is protective, the J mtDNA haplogroup is high risk for AMD. Ultraviolet (UV) radiation is one of the risk factors of AMD and recent studies have demonstrated that after UV treatment, transmitochondrial cybrids (cytoplasmic hybrids) with either H or J mtDNA haplogroups show differential expression of inflammation-related genes. The purpose of this study was to examine and compare the expression profiles of an inflammasome-related gene, IL-1β, in UV-treated and untreated H and J cybrids.
Platelets isolated from subjects with either H or J haplogroup mtDNA were fused with a human retinal pigment epithelial cell line (ARPE-19) that was devoid of mitochondrial DNA (Rho0 cells). In cybrid lines, all of the cells carried the same nuclear genes but varied in mtDNA content. H and J cybrids (n=3) were cultured for 24 hours, followed by exposure to a 10 s pulse of 10 mJ UV-radiation. RNA was isolated at 72 h after UV treatment and gene expression profiles were analyzed using quantitative RT-PCR. Untreated H cybrids served as controls.
Differential gene expression of IL-1β, an inflammatory cytokine, was observed between H cybrids and J cybrids. At the 72 h time point, untreated J cybrids showed significantly decreased expression of IL-1β gene compared to untreated H cybrids (ΔΔCt = -0.2296 ± 0.08, Fold change=0.85, P = 0.0136). Also, IL-1β gene expression was significantly lower in UV-treated J cybrids compared to UV-treated H cybrids (ΔΔCt = -0.1946 ± 0.038, Fold change = 0.87, P=0.0001). Overall, expression of IL-1β gene was drastically diminished in untreated and UV-treated J cybrids compared to H cybrids at the 72 h time point.
In conclusion, differential gene expression of IL-1β was observed between untreated and UV-treated H cybrids and J cybrids. Since all cybrids had the same nuclear DNA content and differed only in their mtDNA content, changes observed in IL-1β gene expression can be attributed to mtDNA variations. Further studies are required to examine the pathway of IL-1β maturation.
This PDF is available to Subscribers Only