Leber's hereditary Optic Neuropathy: repurposing FDA-approved molecules to identify potential leads.

摘要

Purpose : Leber's hereditary Optic Neuropathy (LHON) is one of the commonest inherited mitochondrial diseases, in which mitochondrial complex 1 mutations cause optic atrophy and vision loss. Currently there is no FDA-approved therapy for LHON and few ongoing clinical trials. We took a repurposing approach to LHON by screening FDA-approved drugs for their ability to rescue a LHON-specific cellular defect. Methods : We determined a LHON-dependent defect in mitochondrial complex 1-driven ATP synthesis, that could be assayed in high throughput using the human osteosarcoma LHON cellular hybrids (Z' a?￥ 0.4). We screened a FDA-approved small-molecule drug library of 1600 drugs though this assay in duplicate. The hits identified were reconfirmed in a concentration-dependent response in the same assay. Results : A LHON-specific defect in complex I-dependent ATP synthesis was determined, and this biochemical parameter was reduced in cells bearing the three commonest LHON mutations, 11778, 3460, and 14484, in proportion to their severity. Then, 1600 drugs were screened in an optimized high-throughput assay for their effect to rescue this parameter in 11778(GA) cells, to identify 34 protective molecules. Of those 34, 2 were consistently protective in six-point concentration-response curves. These drugs rescued complex-1 driven ATP synthesis both in mutants and controls. Mechanistic experiments suggested a mechanism related to the cyclic AMP pathway. Conclusions : LHON mutations can cause defects in mitochondrial complex 1-mediated ATP synthesis under stress, which can be rescued at the cellular level. Thus, these are the first-ever drugs to rescue a LHON-specific defect in cells, and the first-ever demonstration of a small molecule that increases complex-I driven ATP synthesis. Tests in animal models of LHON are the next step to support or refute their therapeutic potential. This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.