Abstract
Autosomal dominant optic atrophy (ADOA) is a dominantly inherited optic neuropathy, affecting the specific loss of retinal ganglion cells (RGCs). The majority of affected cases of ADOA are associated with mutations in OPA1 gene. Our previous investigation identified the c.1198C > G (p.P400A) mutation in the OPA1 in a large Han Chinese family with ADOA. In this report, we performed a functional characterization using lymphoblostoid cell lines derived from affected members of this family and control subjects. Mutant cell lines exhibited the aberrant mitochondrial morphology. A ~24.6% decrease in the mitochondrial DNA (mtDNA) copy number was observed in mutant cell lines, as compared with controls. Western blotting analysis revealed the variable reductions (~45.7%) in four mtDNA-encoded polypeptides in mutant cell lines. The impaired mitochondrial translation caused defects in respiratory capacity. Furthermore, defects in mitochondrial ATP synthesis and mitochondrial membrane potential (ΔΨm) were observed in mutant cell lines. These abnormalities resulted in the accumulation of oxidative damage and increasing of apoptosis in the mutant cell lines, as compared with controls. All those alterations may cause the primary degeneration of RGCs and subsequent visual loss. These data provided the direct evidence for c.1198C > G mutation leading to ADOA. Our findings may provide new insights into the understanding of pathophysiology of ADOA.
Highlights
Autosomal dominant optic atrophy (ADOA, OMIM 165500) is the most common inherited optic neuropathies, affecting one individual per 12,000 to 35,0001, 2
These cell lines were assessed for the effects of the OPA1 mutation on mitochondrial morphology, mitochondrial DNA (mtDNA) copy number, oxygen consumption ratio (OCR), ATP production, mitochondrial membrane potential, generation of reactive oxygen species (ROS) and sensitivity to apoptosis
Immortalized lymphoblastoid cell lines used for biochemical assays were derived from three affected members carrying the c.1198C > G mutation and one vision normal member lacking the mutation of the family, and two genetically unrelated control individuals with the same mitochondrial background (Supplementary Figure 1a)
Summary
Autosomal dominant optic atrophy (ADOA, OMIM 165500) is the most common inherited optic neuropathies, affecting one individual per 12,000 to 35,0001, 2. The primary defects of OPA1 were the altered mitochondrial fusion and morphology[15,16,17] These mutations affected the mitochondrial genome www.nature.com/scientificreports/. The sequencing analysis of entire OPA1 gene identified a novel c.1198C > G (p.P400A) heterozygous mutation at the exon 12 in all affected members of this family. To further investigate the pathogenic mechanism of the c.1198C > G (p.P400A) mutation, lymphoblastoid cell lines were generated from 3 affected members carrying the c.1198C > G mutation and 3 control subjects lacking any of OPA1 mutation These cell lines were assessed for the effects of the OPA1 mutation on mitochondrial morphology, mtDNA copy number, oxygen consumption ratio (OCR), ATP production, mitochondrial membrane potential, generation of reactive oxygen species (ROS) and sensitivity to apoptosis
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
