• BMB Reports
• /
• v.49 no.2
• /
• pp.69-70
• /
• 2016

Mutations of orthodentricle homeobox 2 (OTX2) in human and mice often cause retinal dystrophy and nyctalopia, suggesting a role of OTX2 in mature retina, in addition to its functions in the development of the eye and retina. In support of this, the number of bipolar cells in Otx2^+/− post-natal mouse retina was found to be significantly lower than normal. Degeneration of the cells becomes greater as the mice age, leading to the loss of vision. Especially, the type-2 OFF-cone bipolar cells, which do not express Otx2 mRNA but carry Otx2 protein, are most sensitive to Otx2 haplodeficiency. Interestingly, this bipolar cell subpopulation imports Otx2 protein from photoreceptors to protect itself from glutamate excitotoxicity in the dark. Moreover, in the bipolar cells, the exogenous Otx2 relocates to the mitochondria to support mitochondrial ATP synthesis. This novel mitochondrial activity of exogenous Otx2 highlights the therapeutic potential of Otx2 protein transduction in retinal dystrophy.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.22 no.2
• /
• pp.37-45
• /
• 2022

Inherited metabolic disorders (IMD) are a large group of rare disorders affecting normal biochemical pathways. The ophthalmic involvement can be very varied affecting any part of the eye, including abnormalities of cornea, lens dislocation and cataracts, retina and the optic nerve, and extraocular muscles. Eye disorders can be initial symptoms of some IMD and can be clue for diagnosis of IMD. However, eye disorders can evolve later in the natural history of an already diagnosed metabolic disorder. Awareness of IMDs is important to facilitate early diagnosis and in some cases instigate early treatment if a patient presents with eye involvement suggestive of a metabolic disorder. Ophthalmological interventions are also an important component of the multisystem holistic approach to treating patients with metabolic disorders.