Mitochondrial tRNAGlu 14693A>G Mutation, an “Enhancer” to the Phenotypic Expression of Leber’s Hereditary Optic Neuropathy

Leber’s hereditary optic neuropathy (LHON), a maternally inherited ocular disease, is predominantly caused by mitochondrial DNA (mtDNA) mutations. Mitochondrial tRNA variants are hypothesized to amplify the pathogenic impact of three primary mutations. However, the exact mechanisms remained unclear. In the present study, the synergistic effect of the tRNA^(Glu) 14693A>G and ND6 14484T>C mutations in three Chinese families affected by LHON is investigated. The m.14693A>G mutation nearly abolishes…

Defective post-transcriptional modification of tRNA disrupts mitochondrial homeostasis in Leber’s hereditary optic neuropathy

Leber’s Hereditary Optic Neuropathy (LHON) is a rare, maternally inherited eye disease, predominantly due to the degeneration of retinal ganglion cells (RGCs). It is associated with a mitochondrial DNA (mtDNA) point mutation. Our previous study identified that the m.15927G>A homoplasmic mutation damaged the highly conserved basepairing (28C-42G) in anticodon stem of tRNA^(Thr), caused deficient t⁶A modification and significantly decreased efficiency in aminoacylation and steady-state levels of…

Metabolic Deficits in the Retina of a Familial Dysautonomia Mouse Model

Neurodegenerative retinal diseases such as glaucoma, diabetic retinopathy, Leber’s hereditary optic neuropathy (LHON), and dominant optic atrophy (DOA) are marked by progressive death of retinal ganglion cells (RGC). This decline is promoted by structural and functional mitochondrial deficits, including electron transport chain (ETC) impairments, increased oxidative stress, and reduced energy (ATP) production. These cellular mechanisms associated with progressive optic nerve atrophy have been…

Dysregulation of mitochondria, apoptosis and mitophagy in Leber’s hereditary optic neuropathy with MT-ND1 3635G>A mutation

Leber’s hereditary optic neuropathy (LHON) is a maternal inherited disorder, primarily due to mitochondrial DNA (mtDNA) mutations. This investigation aimed to assess the pathogenicity of m.3635G>A alteration known to confer susceptibility to LHON. The disruption of electrostatic interactions among S110 of the MT-ND1 and the side chain of E4, along with the carbonyl backbone of M1 in the NDUFA1, was observed in complex I of cybrids with m.3635G>A. This disturbance affected the complex I assembly…

MSC-mediated mitochondrial transfer restores mitochondrial DNA and function in neural progenitor cells of Leber’s hereditary optic neuropathy

Leber’s hereditary optic neuropathy (LHON) is a debilitating mitochondrial disease associated with mutations in mitochondrial DNA (mtDNA). Unfortunately, the available treatment options for LHON patients are limited due to challenges in mitochondrial replacement. In our study, we reprogramming LHON urine cells into induced pluripotent stem cells (iPSCs) and differentiating them into neural progenitor cells (NPCs) and neurons for disease modeling. Our research revealed that LHON neurons exhibited…

Inhibition of angiogenesis by the secretome from iPSC-derived retinal ganglion cells with Leber’s hereditary optic neuropathy-like phenotypes

The blood supply in the retina ensures photoreceptor function and maintains regular vision. Leber’s hereditary optic neuropathy (LHON), caused by the mitochondrial DNA mutations that deteriorate complex I activity, is characterized by progressive vision loss. Although some reports indicated retinal vasculature abnormalities as one of the comorbidities in LHON, the paracrine influence of LHON-affected retinal ganglion cells (RGCs) on vascular endothelial cell physiology remains unclear. To…

A Comprehensive Review of Leber Hereditary Optic Neuropathy and Its Association with Multiple Sclerosis-Like Phenotypes Known as Harding’s Disease

Leber Hereditary Optic Neuropathy (LHON) stands as a distinctive maternally inherited mitochondrial disorder marked by painless, subacute central vision loss, primarily affecting young males. This review covers the possible relationship between LHON and multiple sclerosis (MS), covering genetic mutations, clinical presentations, imaging findings, and treatment options. LHON is associated with mutations in mitochondrial DNA (mtDNA), notably m.11778G>A, m.3460G>A, and m.14484T>C, affecting complex…