Skin fibroblasts derived from Leber's hereditary optic neuropathy patients present mitochondrial dysfunction / 中华眼底病杂志

Objective:To investigate the feasibility of immoribund skin fibroblast cell line derived from Leber's hereditary optic neuropathy (LHON) patients as a cell model.Methods:A basic research. Two LHON patients and 2 healthy volunteers were recruited from Department of Ophthalmology of Genetic Clinic of Henan Provincial Eye Hospital. The skin tissue of participants was obtained, and the 4 immortalized skin fibroblasts were constructed by SV40 virus infection, including 2 LHON patient cells (LHON-1 and LHON-2 cells) and 2 healthy volunteers cells (NC-1 and NC-2 cells). Mitochondrial morphology in cells was observed by electron microscope. The levels of reactive oxygen species (ROS), nicotinamide adenine dinucleotide-oxidation state (NAD +), nicotinamide adenine dinucleotide-reduction state (NADH) and adenosine triphosphate (ATP) in fibroblasts were detected. Cellular oxygen consumption was measured by seahorse mitochondrial pressure assay. Cell viability was detected using cell counting kit-8 (CCK8). One-way ANOVA was performed to compare the levels of ROS, NAD +, NADH and ATP in LHON and NC cells, as well as basal oxygen consumption, maximal oxygen consumption, ATP-coupled oxygen consumption, and cell viability. Results:Compared with NC-1 and NC-2, the number of mitochondrial crest in LHON fibroblasts was significantly reduced, indicating abnormal mitochondrial morphology. Biochemical analysis showed that ROS levels in LHON cells increased, but NAD +/NADH and ATP levels decreased, and the oxygen consumption was significantly inhibited, indicating the presence of mitochondrial damage and respiratory dysfunction. The results of CCK-8 detection showed that the survival ability of LHON-1 and LHON-2 cells was worse under stress conditions. Conclusion:Immortalized skin fibroblast cell lines from LHON patients presented mitochondrial dysfunction.

Association between visual function and optic fiber layer thickness after gene therapy for Leber hereditary optic neuropathy / 中华实验眼科杂志

Objective:To investigate the association between the rehabilitation of visual function and retinal nerve fiber layer (RNFL) thickness in Leber hereditary optic neuropathy (LHON) patients receiving gene therapy for the disease.Methods:A multi-center, non-randomized, single-arm clinical trial was conducted.A total of 159 LHON patients were enrolled in Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Taihe Hospital and Ezhou Central Hospital from December 2017 to December 2018.All of the patients were administered with a single unilateral intravitreal injection (0.05 μl) of recombinant adeno-associated virus 2 carrying reduced nicotinamide adenine dinucleotide dehydrogenase subunit 4 (rAAV2-ND4) and were followed up before and 1, 3, 6 and 12 months after treatment.The best corrected visual acuity (BCVA) converted to logarithm of the minimum angle of resolution (LogMAR) unit was assessed with a standard logarithmic visual acuity chart.Perimetry indicators including visual field index (VFI) and mean deviation (MD) were measured with Humphrey Field Analyzer.RNFL thickness in the superior, inferior, temporal, nasal optic disc and the average RNFL thickness were detected with Spectralis ? HRA+ OCT.The 12-month postoperative BCVA, visual field, and RNFL thickness were taken as the primary outcomes.According to the improvement of BCVA, VFI and MD at 12 months after therapy, there were 81 vision improved eyes with injection, 62 vision unimproved eyes with injection, 65 vision improved eyes without injection, and 78 vision unimproved eyes without injection, 48 VFI improved eyes with injection, 71 VFI unimproved eyes with injection, 47 VFI improved eyes without injection, and 72 VFI unimproved eyes without injection, 52 MD improved eyes with injection, 67 MD unimproved eyes with injection, 47 MD improved eyes without injection, and 72 MD unimproved eyes without injection.The correlations between BCVA, VFI, MD and RNFL thickness were evaluated by Pearson linear correlation analysis.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committees of Wuhan Tongji Hospital (No.TJ-IRB20180316), Taihe Hospital (No.2017-01), Ezhou Central Hospital (No.2017-K-05) and People's Hospital of Wuhan University (No.WDRY2020-K202).Written informed consent was obtained from each patient or custodian prior to entering the study cohort. Results:Among the patients receiving rAAV-ND4 gene therapy, the 12-month postoperative BCVA (LogMAR) in the injected eyes and uninjected eyes was 1.37±0.55 and 1.29±0.59, which were significantly better than 1.70±0.41 and 1.53±0.51 before treatment (baseline), respectively ( t=4.920, 3.550; both at P<0.001).The 12-month postoperative VFI of the patients were significantly improved and the 12-month postoperative MD of the patients were significantly lowered in comparison with those at baseline in the injected eyes (both at P<0.001).Similar improvements of VFI and MD were observed in the uninjected eyes (both at P<0.01).RNFL of the patients was thinner after the therapy.In the vision improved eyes with injection, the BCVA was negatively correlated with superior, inferior, temporal, nasal and average RNFL thickness ( r=-0.362, -0.292, -0.307, -0.308; all at P<0.05).In the VFI improved eyes with injection, VFI was positively correlated with superior, inferior, nasal and average RNFL thickness ( r=0.439, 0.356, 0.294, 0.401; all at P<0.05).In the MD improved eyes with injection, MD was positively correlated with superior, inferior, nasal and average RNFL thickness ( r=0.495, 0.424, 0.377, 0.474; all at P<0.05). Conclusions:The recovery of visual function is associated with RNFL thickness after the intravitreal injection of rAAV2-ND4 in LHON eyes.Recovery of visual acuity is better in the eyes with thicker RNFL.

Research progress of optical coherence tomography and optical coherence tomography angiography in Leber hereditary optic neuropathy / 中华眼底病杂志

Leber hereditary optic neuropathy (LHON) is a maternally inherited mitochondrial disease. It is clinically recognizable by painless, bilateral loss of vision, and the prognosis of vision is generally poor. In recent years, the information provided by optical coherence tomography (OCT) and OCT angiography (OCTA) has greatly improved people's understanding of LHON, and new progress has been made in the intervention and treatment of LHON. A detailed understanding of the structural changes of retina and choroid under OCT and OCTA of the natural course and after treatment of LHON, may provide reference for revealing the pathogenesis, prediction of onset time, differential diagnosis, follow-up of treatment effect and prognosis of LHON.

Progress and challenges in diagnosis and treatment of Leber's hereditary optic neuropathy / 中华眼底病杂志

Leber's hereditary optic neuropathy (LHON) is a rare hereditary optic nerve disease. At present, the understanding of its etiology and pathogenesis is relatively clear. With the emergence of new drugs such as idebenone and the possibility of gene therapy for LHON, it has brought hope for patients to recover. However, because genetic testing technology has not been widely developed in China, clinical misdiagnosis of LHON as optic neuritis still occurs from time to time. How to make timely identification and correct diagnosis of LHON still poses certain challenges for Chinese ophthalmologists. In addition, in terms of treatment, the choice of treatment methods and treatment costs in the pre-onset (gene mutation carriers) and different periods after the onset of LHON are also huge challenges for patients and their families.

Observation of penetrance and retinal nerve fiber layer and macular thickness in patients with Leber's hereditary optic neuropathy / 中华眼底病杂志

Objective To observe the effects of penetrance,different time of onset and mutation sites on retinal nerve fiber layer (RNFL) and macular thickness in patients with Leber's hereditary optic neuropathy (LHON).Methods This was a cross-sectional observational study.A total of 88 patients with LHON and 1492 relatives of the maternal relatives (gene carriers) who received treatment in People's Liberation Army General Hospital from 2015 to 2017 were included in the study.Among the 1492 family members,there were 694 males and 798 females.Peripheral venous blood was extracted from all subjects for mitochondrial DNA testing,and penetrance was calculated.A total of 117 patients underwent BCVA and SD-OCT examinations,including 82 patients and 35 gene carriers.The BCVA examination was performed using the Snellen visual acuity chart,which was converted into logMAR visual acuity.The thickness of RNFL,ganglion cell complex (GCC) and inner limiting membrane (ILM)-RPE were measured with OCT instrument.The mean follow-up was 50.02± 86.27 months.The disease course was divided into 6 stages including ≤3 months,4-6 months,7-12 months and ＞ 12 months.The thickness of RNFL,GCC and ILM-RPE in patients with different time of onset and mutation sites were comparatively analyzed by covariance analysis.Categorical variables were expressed as a percentage,and the x2 test was used for comparison among multiple groups.Results Among the 1492 family members,285 were diagnosed with LHON and highly suspected clinical manifestations (19.10％),including 190 males (21.98％) and 95 females (11.90％).The total penetrance rates of 11778,14484 and rare mutation sites were 19.84％ (228/1149),20.50％ (33/161),and 13.19％ (24/182) respectively;male penetrance rates were 28.87％ (153/530),27.28％ (20/72),and 18.48％ (17/92) and female penetrance rates were 12.12％ (75/619),14.61％ (13/89) and 7.78％ (7/90).There was no significant difference in total (x2=4.732),male (x2=4.263) and female (x2=4.263) penetrance between different mutation sites (P=0.094,0.110,0.349).Compared with non-pathogenic carriers,the thickness of the RNFL,GCC and ILM-RPE were all different in the four stages (≤3months,4-6 months,7-12 months and ＞12 months).The thickness ofRNFL,GCC and ILM-RPE decreased with the time of onset (P=0.000).There were significant differences in the thickness of each of the GCC and ILM-RPE layers in the macular area of LHON patients with different mutation sites (P＜ 0.05).Among them,the site 11778 and 3460 had the most severe damage in all quadrants of macular GCC and ILM-RPE layer,followed by 14484 site,and the rare site had the least damage in all quadrants.Conclusions The penetrance of LHON patients is 19.10％.With the extension of the onset time (within 1 year),the RNFL layer of the optic disc and all quadrants of the macular GCC and ILM-RPE layer gradually thinned.Compared with 11778 and rare site,14484 site,and the rare site had the lighter damage on the thickness of RNFL,GCC and ILM-RPE.

Study on transfection of adeno associated virus 2-ND4 gene into mitochondria / 中华实验眼科杂志

Background Leber hereditary optic neuropathy (LHON) is mitochondrial DNA (mtDNA) disease and mainly leads to optical nerve degeneration.Its primary mechanism is synthesis disorder of DN4 protein due to variation of mtDNA 11778 locus.So to construct a vector with exogenous normal ND4 and transfect into mitochondria is a key of gene therapy for LHON.Objective This study was to investigate the in vitro transfection of adeno-associated virus (AAV)-ND4 gene into mitochondria.Methods Human renal epithelial cell lines transfected adenovirus E1A (293 cells) were regularly cultured and divided into two groups.Framework plasmids of recombinant AAV-ND4 or simple AAV2 were added to the cell medium respectively.The expression of ND4 in cells were located 12,24,36 and 48 hours after transfected by Y03 dual fluorescent quantum dots staining.The positive response for ND4 showed the green fluorescence.Results Cultured 293 cells grew well with 80％ confluence.Abundant green fluorescence particles were seen in cytoplasm in the AAV-ND4 transfected group,but only red fluorescence from mitochondrial protein was seen in the simple AAV transfected group under the fluorescence microscope.Conclusions Exogenous ND4 protein can been successfully transfected into mitochondria using the ND4 gene constructed AAV.This result provides experimental evidence for the further study on gene therapy of LHON.

Neuromyelitis optica antibody in Leber hereditary optic neuropathy: case report / Anticorpo da neuromielite óptica em neuropatia óptica hereditária de Leber: relato de caso

Neuromyelitis optica antibody (or aquaporin-4 antibody) is a well stablished serum marker associated to high-risk neuromyelitis optica syndrome that presents as an inflammatory demyelinating disease characterized by the occurrence of bilateral and simultaneous optic neuritis without complete visual recovery or it occurs as an isolated episode of transverse myelitis accompanied by longitudinally extensive spinal cord lesions. On the other hand, Leber hereditary optic neuropathy is a primarily hereditary disorder that affects all tissues of the body and its clinical presentation is tissue-specific for the optic nerve and, eventually, it might reach the spinal cord. Overlapping clinical features of neuromyelitis optica and Leber hereditary optic neuropathy may suggest common target organ diseases. The case report described herein emphasizes the coexistence of serum markers of both diseases, and suggests that further investigation of this challenging clinical presentation is warranted to confirm or rule out this association.

Anticorpo da neuromielite óptica (ou anticorpo aquaporina-4) é um marcador sorológico bem estabelecido associado à síndrome de alto risco para neuromielite óptica, doença inflamatória desmielinizante, caracterizada por ocorrência bilateral, simultânea de neurite óptica ou por episódio isolado de mielite transversa com achado de lesões espinais longitudinais extensas. Por outro lado, a neuropatia óptica hereditária de Leber é uma doença primariamente hereditária que afeta todos os tecidos do corpo e sua apresentação clínica envolve o nervo óptico e, eventualmente, a medula espinal. Aspectos clínicos comuns sugerem que neuromielite óptica e neuropatia óptica hereditária de Leber possam atingir os mesmos órgãos. O caso descrito enfatiza a coexistência de marcadores sorológicos das duas doenças e sugere a necessidade de investigação futura desta apresentação clínica atípica para confirmar ou não esta associação.

Leber's Hereditary Optic Neuropathy with 3460 Mitochondrial DNA Mutation

Leber's hereditary optic neuropathy (LHON) is a maternally transmitted disease causing acute or subacute, bilateral optic atrophy mainly in young men. It is found to be a mitochondrial disorder with the primary mitochondrial DNA (mtDNA) mutations at 11778, 3460, and 14484. The incidence of each mutation is reported to be race-dependent. Point mutations at mtDNA nucleotide position 11778 and 14484 have been reported in Korean patients with LHON, however there has been no report of mtDNA mutation at nucleotide position 3460. Molecular genetic analyses at four primary sites (11778, 14484, 15257, and 3460) of mitochondrial DNA using the polymerase chain reaction, restriction enzyme digestion, and direct sequencing were performed in a 35-yr-old man with severe visual loss. A point mutation in the mtDNA at nucleotide position 3460 was identified and a conversion of a single alanine to a threonine was confirmed. To our knowledge, this is the first report confirming mtDNA mutation at nucleotide position 3460 in Korean patients with LHON. Detailed molecular analyses would be very helpful for the correct diagnosis of optic neuropathy of unknown etiology and for genetic counseling.