Purchase this article with an account.
Janelle M. Pavlis, Marilyn Chwa, Claudio A. Ramirez, Nitin Udar, S M. Jazwinski, M V. Miceli, Vishal R. Sharma, M. C. Kenney, Rhina M. Piche Lopez; Comparison of Cybrids from Different Mitochondrial DNA (mtDNA) Haplogroups, Implications for Age-related Macular Degeneration (AMD). Invest. Ophthalmol. Vis. Sci. 2012;53(14):4762.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
AMD is a leading cause of vision loss in people over 65 years of age. Mitochondrial genetics is a potentially important area of research that will help us understand the genetic predisposition toward AMD. Previous studies have shown that the mtDNA haplogroup J but not haplogroup H is associated with AMD. However, the functional consequences of this difference is not understood. Cybrids (cytoplasmic hybrids) are created by introducing the mitochondria into a host cell line that lacks mitochondria. The resulting cybrids carry the same nuclear genes but vary only in their mitochondrial content. Mitochondria representing different haplogroups can therefore be introduced and compared. In this study, some key biochemical pathways representing mitochondrial function were studied. We hypothesize that ARPE-19 cells, dissimilar only in their mtDNA haplogroup will behave differently in vitro.
Cybrids were created by fusing platelets from individuals with either H or J mtDNA haplogroups with rho0 ARPE-19 cells which lack mitochondria. Reactive oxygen and nitrogen species (ROS/RNS) levels were determined using the 2’, 7’-dichlorodihydrofluorescein diacetate (H2DCFDA) dye assay, ATP production was measured using the ATPlite luminescent detection assay, mitochondrial membrane potential (ΔΨm) was quantified using a mitochondrial membrane potential detection assay, apoptosis and necrosis were measured using the Membrane Permeability/Dead Cell Apoptosis kit. Values were compared using relative percentages.
ATP production was 35-62% higher in haplogroup H compared to J (p <0.002). There was a 25% reduction in apoptosis and necrosis in haplogroup H versus J (p< 0.02), and haplogroup H produced 22% more ROS/RNS compared to haplogroup J (p=0.007). There was no statistically significant difference in mitochondrial membrane potential.
This study examines characteristics of cells that are identical except for their mtDNA. These preliminary findings suggest that mtDNA haplogroup differences have functional consequences for cells in vitro. This data may have implications for understanding why haplogroup J is associated with AMD. More research is needed to understand unique haplogroup features which relate to the development of diseases.
This PDF is available to Subscribers Only