DeCure for Mitochondrial complex I deficiency, nuclear type 18
DeCure's autonomous Metabolic AI scientist is researching a drug-repurposing hypothesis for mitochondrial complex I deficiency, nuclear type 18 — screening already-approved drugs against its 2-gene Open Targets disease module to publish open-access research. Research is fast; the path to publication is funded in milestone stages.
Disease moduleMitochondrial complex I deficiency, nuclear type 18 maps to a 2-gene Open Targets module — the target space DeCure's AI scientist screens approved drugs against.
DeCure.ai methodSignature reversal (LINCS) plus network proximity (STRING) rank already-approved drugs likely to perturb this module — the same engine that produces DeCure.ai's repurposing hypotheses.
Repurposing thesisScreening approved medicines against this disease module, then publishing the evidence for the strongest candidate. Known pharmacology and human exposure data make the first question sharper — they do not establish safety or efficacy in a new indication.
Research record
01
ResearchComing soon
Candidate research + dossier — target rationale, drug-repurposing thesis and evidence pack.proof: Published dossier + on-chain hash
02
ValidationComing soon
In-vitro biological validation at a contract research org (CRO).proof: CRO contract + in-vitro report
03
Peer review & paperComing soon
Peer-reviewed paper published open-access (preprint + journal).proof: DOI + open-access link + on-chain hash
Current lead
No approved-drug candidate for mitochondrial complex i deficiency, nuclear type 18 is corroborated in the literature DeepSearch retrieved. Some conditions are managed with non-pharmacological care — a device, surgery or physical therapy — rather than a medicine; that may be the case here, or the literature we found may simply be too sparse yet to support a drug-repurposing angle.
What the evidence adds up to
Mitochondrial complex I deficiency, nuclear type 18, is one of the most common inherited disorders of oxidative phosphorylation, with a birth prevalence of roughly 1 in 5,000 for all OXPHOS disorders. A 2011 review of 149 patients with isolated complex I deficiency and pathogenic mutations in nuclear genes found 115 different mutations across 22 nuclear genes encoding complex I subunits or assembly factors. No single gene accounted for more than 5% of cases, and many patients still receive no molecular diagnosis, suggesting many disease genes remain unidentified. The NDUFS4 subunit has been a focus of cellular and animal models for studying human complex I deficiency, as reviewed in 2013.
A 2003 study of the mitochondrial DNA G13513A mutation in the ND5 subunit found that this mutation caused Leigh's disease and complex I deficiency at mutant loads of approximately 50% or less in all tested tissues, including multiple brain regions. The threshold for causing a complex I defect in cultured cells was around 30% mutant load. Fibroblasts with 45% G13513A mutant load had about 50% of the normal amount of fully assembled complex I, while fibroblasts with over 97% of the ND6 G14459A mutation had only 20% fully assembled complex I. The authors concluded that G13513A acts at unusually low mutant loads and may act dominantly.
A 2008 study examined trabecular meshwork cells from primary open-angle glaucoma patients and found that these cells have higher endogenous reactive oxygen species levels, lower ATP levels, and decreased mitochondrial membrane potential compared to normal cells. They were more sensitive to complex I inhibition by rotenone than normal cells. Rotenone induced further ROS increase, cytochrome c release, ATP decrease, and membrane potential loss, leading to apoptosis. Complex II and III inhibitors had little effect. Antioxidants vitamin E and N-acetylcysteine protected against rotenone-induced death by inhibiting ROS generation and cytochrome c release. The authors proposed that a mitochondrial complex I defect is associated with trabecular meshwork cell degeneration in glaucoma, and that antioxidants and mitochondrial permeability transition inhibitors can reduce progression in that context.
What is still missing for mitochondrial complex I deficiency, nuclear type 18 specifically: no clinical trial has tested any intervention in patients with confirmed nuclear gene mutations causing this disorder. The antioxidant data come from glaucoma cells, not from patients with nuclear type 18. No gene has been identified that accounts for more than 5% of nuclear complex I deficiency cases, meaning most patients lack a molecular diagnosis. Funding for systematic patient stratification and for trials that measure survival or developmental outcomes in genetically defined subgroups remains absent.
Evidence
Retrieved by DeepSearch across 234,678,978 indexed works and resolved on OpenAlex — ranked by citations, including the results that did not work.
Mitochondrial Complex I Defect Induces ROS Release and Degeneration in Trabecular Meshwork Cells of POAG Patients: Protection by Antioxidants
AbstractPURPOSE: There is growing evidence that oxidative stress contributes to the progression of primary open-angle glaucoma (POAG), a leading cause of irreversible blindness worldwide. The authors provide evidence that mitochondrial dysfunction is a possible mechanism for the loss of trabecular meshwork (TM) cells in persons with POAG. METHODS: TM from patients with POAG (GTM) and age-matched subjects without disease (NTM) were obtained by standard surgical trabeculectomy. Primary TM cultures were treated with one of the following mitochondrial respiratory chain inhibitors: rotenone (ROT, complex I inhibitor), thenoyltrifluoroacetone (TTFA, complex II inhibitor), myxothiazol or antimycin A (MYX, AM-complex III inhibitors); mitochondrial permeability transition (MPT) inhibitor cyclosporine A (CsA); and antioxidants vitamin E (Vit E) or N-acetylcysteine (NAC). Mitochondrial function was determined by changes in mitochondrial membrane potential (DeltaPsim) and adenosine triphosphate (ATP) production with the fluorescent probes 5,5',6,6'-tetrachloro-1,1'3,3'-tetraethylbenzimid azolocarbocyanine iodide (JC-1) and a luciferin/luciferase-based ATP assay, respectively. Reactive oxygen species (ROS) level, determined by H(2)-DCF-DA, and cell death, measured by lactate dehydrogenase activity and Annexin V-FITC labeling, were also examined. RESULTS: GTM cells have higher endogenous ROS levels, lower ATP levels, and decreased Delta Psi m and they are more sensitive to mitochondrial complex I inhibition than their normal counterparts. ROT induces a further increase in ROS production, the release of cytochrome c, and decreases in ATP level and Delta Psi m in GTM cells, eventually leading to apoptosis. Complex II and III inhibition had little effect on the cells. Antioxidants protect against ROT-induced death by inhibiting ROS generation and cytochrome c release. CONCLUSIONS: The authors propose that a mitochondrial complex I defect is associated with the degeneration of TM cells in patients with POAG, and antioxidants and MPT inhibitors can reduce the progression of this condition.
Low mutant load of mitochondrial DNA G13513A mutation can cause Leigh's disease
AbstractRespiratory chain complex I deficiency is a common cause of Leigh's disease (LD) and can be caused by mutations in genes encoded by either nuclear or mitochondrial DNA (mtDNA). Most pathogenic mtDNA mutations act recessively and only cause disease when present at high mutant loads (typically >90%) in tissues such as muscle and brain. Two mitochondrial DNA mutations in complex I subunit genes, G14459A in ND6, and T12706C in ND5, have been associated with complex I deficiency and LD. We report another ND5 mutation, G13513A, in three unrelated patients with complex I deficiency and LD. The G13513A mutation was present at mutant loads of approximately 50% or less in all tissues tested, including multiple brain regions. The threshold mutant load for causing a complex I defect in cultured cells was approximately 30%. Blue Native polyacrylamide gel electrophoresis showed that fibroblasts with 45% G13513A mutant load had approximately 50% of the normal amount of fully assembled complex I. Fibroblasts with greater than 97% of the ND6 G14459A mutation had only 20% fully assembled complex I, suggesting that both mutations disrupt complex I assembly or turnover. We conclude that the G13513A mutation causes a complex I defect when present at unusually low mutant load and may act dominantly.
Cellular and animal models for mitochondrial complex I deficiency: A focus on the NDUFS4 subunit
AbstractTo allow the rational design of effective treatment strategies for human mitochondrial disorders, a proper understanding of their biochemical and pathophysiological aspects is required. The development and evaluation of these strategies require suitable model systems. In humans, inherited complex I (CI) deficiency is one of the most common deficiencies of the mitochondrial oxidative phosphorylation system. During the last decade, various cellular and animal models of CI deficiency have been presented involving mutations and/or deletion of the Ndufs4 gene, which encodes the NDUFS4 subunit of CI. In this review, we discuss these models and their validity for studying human CI deficiency.
AbstractDisorders of oxidative phosphorylation (OXPHOS) have a birth prevalence of ∼1/5,000 and are the most common inborn errors of metabolism. The most common OXPHOS disorder is complex I deficiency. Patients with complex I deficiency present with variable symptoms, such as muscle weakness, cardiomyopathy, developmental delay or regression, blindness, seizures, failure to thrive, liver dysfunction or ataxia. Molecular diagnosis of patients with complex I deficiency is a challenging task due to the clinical heterogeneity of patients and the large number of candidate disease genes, both nuclear-encoded and mitochondrial DNA (mtDNA)-encoded. In this review, we have thoroughly surveyed the literature to identify 149 patients described with both isolated complex I deficiency and pathogenic mutations within nuclear genes. In total, 115 different pathogenic mutations have been reported in 22 different nuclear genes encoding complex I subunits or assembly factors, highlighting the allelic and locus heterogeneity of this disorder. Missense mutations predominate in genes encoding core subunits and some assembly factors while null-type mutations are common in the genes encoding supernumerary subunits and other assembly factors. Despite developments in molecular technology, many patients do not receive molecular diagnosis and no gene has yet been identified that accounts for more than 5% of cases, suggesting that there are likely many disease genes that await discovery.
Mitochondrial DNA Depletion Associated With Partial Complex II and IV Deficiencies and 3-Methylglutaconic Aciduria
AbstractWe report a patient with mitochondrial DNA depletion, partial complex II and IV deficiencies, and 3-methylglutaconic aciduria. Complex II deficiency has not been previously observed in mitochondrial DNA depletion syndromes. The observation of 3-methylglutaconic and 3-methylglutaric acidurias may be a useful indicator of a defect in respiratory chain function caused by mitochondrial DNA depletion.
Journal of Clinical Neuromuscular Disease · 2014 · 5 citations
Mitochondrial Myopathy, Cardiomyopathy, and Pontine Signal Changes in an Adult Patient With Isolated Complex II Deficiency
AbstractMitochondrial disorders resulting from an isolated deficiency of complex II of the respiratory chain is rarely reported. The phenotypic spectrum associated with these disorders is heterogeneous and still expanding. This report describes a patient who presented with myopathy, dilated cardiomyopathy, and pontine signal changes on magnetic resonance imaging. Muscle biopsy showed total absence of succinate dehydrogenase on enzyme histochemistry, negative succinate dehydrogenase subunit A (SDHA) activity on immunohistochemistry, and ultrastructural evidence of mitochondrial aggregates of varying sizes confirming the diagnosis of complex II deficiency. A unique phenotype with complex II deficiency is reported.
Disease module: DeepOracle (Open Targets). Structures: RDKit from PubChem SMILES. Literature: retrieved by DeepSearch across 234,678,978 indexed works (targeted per-candidate search), resolved on OpenAlex.
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