DeCure for Mitochondrial complex I deficiency, nuclear type 2
DeCure's autonomous Metabolic AI scientist is researching a drug-repurposing hypothesis for mitochondrial complex I deficiency, nuclear type 2 — screening already-approved drugs against its 1-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 2 maps to a 1-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 2 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 2, is a childhood-onset disorder that accounts for up to 30% of paediatric mitochondrial disease cases. In a systematic review of published nuclear-encoded complex I deficiency, 117 cases had nuclear subunit mutations and 55 had assembly factor mutations. The most common presentations include Leigh syndrome, leukoencephalopathy, fatal infantile lactic acidosis, hypertrophic cardiomyopathy, and exercise intolerance. Approximately 25% of all complex I deficiency cases have mitochondrial DNA mutations, a further 25% have mutations in a nuclear subunit or in one of nine known assembly factors, and almost half of all cases are due to defects in as yet unidentified genes.
In a 2022 study of 34 patients with isolated complex I deficiency, screening of six nuclear-encoded subunit genes (NDUFV1, NDUFS1, NDUFS2, NDUFS4, NDUFS7, NDUFS8) identified mutations in six patients (18%). Novel mutations were found in NDUFV1 (R386H, K111E, P252R), NDUFS2 (R221X, M292T, R333Q, IVS9+4A>G), and NDUFS4 (c.221delC). All six patients had progressive encephalopathy, and five had Leigh syndrome or a Leigh-like syndrome. No specific genotype-phenotype correlations were identified.
Research in non-neurological contexts has examined the cellular consequences of complex I inhibition. In trabecular meshwork cells from primary open-angle glaucoma patients, endogenous reactive oxygen species levels were higher, ATP levels lower, and mitochondrial membrane potential decreased compared to normal cells. These cells were more sensitive to complex I inhibition by rotenone, which further increased ROS production, triggered cytochrome c release, and induced apoptosis. Antioxidants vitamin E and N-acetylcysteine protected against rotenone-induced death by inhibiting ROS generation and cytochrome c release. However, these findings come from a glaucoma model, not from patients with nuclear-encoded complex I deficiency.
Treatment trials have been carried out only in patient-derived cell lines, using chemical compounds that target cellular aberrations induced by complex I dysfunction. Before human clinical trials can begin, suitable animal models are needed to study toxicity, pharmacokinetics, and therapeutic potential. Two mouse models for nuclear DNA-encoded complex I deficiency exist, but only as tissue-specific knock-outs. What remains missing is a full understanding of the unidentified genes responsible for nearly half of complex I deficiencies, definitive genetic counselling for all affected families, and any clinical trial data in patients with nuclear type 2 disease.
Evidence
Retrieved by DeepSearch across 234,678,978 indexed works and resolved on OpenAlex — ranked by citations, including the results that did not work.
Journal of Medical Genetics · 2012 · 325 citations
Complex I deficiency: clinical features, biochemistry and molecular genetics
AbstractComplex I deficiency is the most frequent mitochondrial disorder presenting in childhood, accounting for up to 30% of cases. As with many mitochondrial disorders, complex I deficiency is characterised by marked clinical and genetic heterogeneity, leading to considerable diagnostic challenges for the clinician, not least because of the involvement of two genomes. The most prevalent clinical presentations include Leigh syndrome, leukoencephalopathy and other early-onset neurodegenerative disorders; fatal infantile lactic acidosis; hypertrophic cardiomyopathy; and exercise intolerance. Causative genetic defects may involve the seven mitochondrial-encoded or 38 nuclear-encoded subunits of the enzyme, or any of an increasing number of assembly factors implicated in the correct biosynthesis of complex I within the inner mitochondrial membrane. In this review, we discuss recent advances in knowledge of the structure, function and assembly of complex I and how these advances, together with new high-throughput genetic screening techniques, have translated into improved genetic diagnosis for affected patients and their families. Approximately 25% of cases have mitochondrial DNA mutations, while a further ∼25% have mutations in a nuclear subunit or in one of nine known assembly factors. We also present a systematic review of all published cases of nuclear-encoded complex I deficiency, including 117 cases with nuclear subunit mutations and 55 with assembly factor mutations, and highlight clinical, radiological and biochemical clues that may expedite genetic diagnosis.
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.
Journal of Inherited Metabolic Disease · 2014 · 63 citations · open access
Mitochondrial disease associated with complex I (NADH‐CoQ oxidoreductase) deficiency
AbstractMitochondrial diseases due to a reduced capacity for oxidative phosphorylation were first identified more than 20 years ago, and their incidence is now recognized to be quite significant. In a large proportion of cases the problem can be traced to a complex I (NADH-CoQ oxidoreductase) deficiency (Phenotype MIM #252010). Because the complex consists of 44 subunits, there are many potential targets for pathogenic mutations, both on the nuclear and mitochondrial genomes. Surprisingly, however, almost half of the complex I deficiencies are due to defects in as yet unidentified genes that encode proteins other than the structural proteins of the complex. This review attempts to summarize what we know about the molecular basis of complex I deficiencies: mutations in the known structural genes, and mutations in an increasing number of genes encoding "assembly factors", that is, proteins required for the biogenesis of a functional complex I that are not found in the final complex I. More such genes must be identified before definitive genetic counselling can be applied in all cases of affected families.
Journal of Inherited Metabolic Disease · 2010 · 31 citations · open access
Mouse models for nuclear DNA‐encoded mitochondrial complex I deficiency
AbstractMitochondrial diseases are a group of heterogeneous pathologies with decreased cellular energy production as a common denominator. Defects in the oxidative phosphorylation (OXPHOS) system, the most frequent one in humans being isolated complex I deficiency (OMIM 252010), underlie this disturbed-energy generation. As biogenesis of OXPHOS complexes is under dual genetic control, with complex II being the sole exception, mutations in both nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) are found. Increasing knowledge is becoming available with respect to the pathophysiology and cellular consequences of OXPHOS dysfunction. This aids the rational design of new treatment strategies. Recently, the first successful treatment trials were carried out in patient-derived cell lines. In these studies chemical compounds were used that target cellular aberrations induced by complex I dysfunction. Before the field of human clinical trials is entered, it is necessary to study the effects of these compounds with respect to toxicity, pharmacokinetics and therapeutic potential in suitable animal models. Here, we discuss two recent mouse models for nDNA-encoded complex I deficiency and their tissue-specific knock-outs.
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.
The role of nuclear-encoded subunit genes in mitochondrial complex 1 deficiency
AbstractBACKGROUND: Mitochondrial complex I deficiency often leads to a devastating neurodegenerative disorder of childhood. In most cases, the underlying genetic defect is unknown. Recessive nuclear gene mutations, rather than mitochondrial DNA mutations, account for the majority of cases. AIM: Our aim was to identify the genetic basis of complex I deficiency in 34 patients with isolated complex I deficiency, by studying six of the 39 nuclear encoded complex I subunit genes (NDUFV1, NDUFS1, NDUFS2, NDUFS4, NDUFS7 and NDUFS8). These genes have been conserved throughout evolution and carry out essential aspects of complex I function. METHODS: RNA was extracted from patient fibroblasts and cDNA made by reverse transcription. Overlapping amplicons that together spanned the entire coding area of each gene were amplified by PCR. The genes were screened for mutations using denaturing High Performance Liquid Chromatography (dHPLC). Patient samples with abnormal dHPLC profiles underwent direct DNA sequencing. RESULTS: Novel mutations were identified in six of 34 (18%) patients with isolated complex I deficiency. Five patients had two mutations identified and one patient had a single mutation in NDUFS4 identified. All patients with mutations had a progressive encephalopathy and five out of six had Leigh syndrome or Leigh like syndrome. Mutations were found in three nuclear encoded subunit genes, NDUFV1, NDUFS2 and NDUFS4. Three novel NDUFV1 mutations were identified (R386H, K111E and P252R). The R386H mutation was found in two apparently unrelated patients. Four novel NDUFS2 mutations were identified (R221X, M292T, R333Q and IVS9+4A&ltG). The novel NDUFS4 mutation c.221delC was found in two patients - one in homozygous form and the other heterozygous. Specific genotype and phenotype correlations were not identified. CONCLUSIONS: Nuclear encoded complex I subunit gene mutations are an important contributor to the aetiology of isolated complex I deficiency in childhood. Screening of these genes is an essential part of the investigation of complex I deficiency.
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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