bims-mignad 2025-07-27 papers

Issue of 2025–07–27
five papers selected by
Melisa Emel Ermert, Amsterdam UMC

Adv Sci (Weinh). 2025 Jul 20. e08503

NAD+-Boosters Improve Mitochondria Quality Control In Parkinson's Disease Models Via Mitochondrial UPR.

Shuoting Zhou, Xi Xiong, Jialong Hou, Qi Duan, Yi Zheng, Tao Jiang, Jiani Huang, Haijun He, Jiaxue Xu, Keke Chen, Wenwen Wang, Jinlai Cai, Jingjing Qian, Huijun Chen, Weihong Song, XinShi Wang, Chenglong Xie.

Serving as a pivotal hub for cellular metabolism and intracellular signaling, the mitochondrion has emerged as a crucial organelle whose dysfunction is linked to many human diseases, including neurodegenerative disorders, particularly Parkinson's disease (PD). However, whether mitochondrial quality control (MQC) can be targeted for therapeutic interventions remains uncertain. This study uses clinical samples, molecular biology techniques, pharmacological interventions, and genetic approaches to investigate the significance of NAD+ levels in cross-species models of PD. These results reveal that treatment of rotenone-incubated cells with NAD+ boosters (such as NMN, siCD38, and NAT) increases UPRmt/mitophagy-related MQC, reduces pro-inflammatory cytokine expression, inhibits apoptosis, and strengthen redox reactions. In vivo, NMN supplementation inhibits motor deficit and forestalls the neuropathological phenotypes of MPTP-induced PD mice, which are required for the atf4-related mitochondrial UPR pathway. Notably, bulk omics signatures and metabolomic profiling analyses of the striatum reveal NMN-induced transcriptional changes in genes and proteins involved in mitochondrial homeostasis. Thus, these findings demonstrate that the accelerated pathology in PD models is probably mediated by impaired MQC and that bolstering cellular NAD+ levels alleviates mitochondrial proteotoxic stress and mitigate PD phenotypes.

Keywords: NAD+‐boosters; Parkinson's disease; mitochondria quality control; mitochondrial unfolded protein response; nicotinamide mononucleotide

DOI: https://doi.org/10.1002/advs.202408503

Cureus. 2025 Jun;17(6): e86670

Mutation of NDUFAF2 Linked to Mitochondrial Complex I Deficiency.

Anwar R Alhamad, Aziza Mushiba, Huda Alkhawaja, AbdullabAli PeerZada, Shahad Bawazeer, Mohammed Saleh.

Mitochondrial complex I deficiency is an autosomal recessive disorder caused by homozygous mutations in the reduced form of nicotinamide adenine dinucleotide (NADH). It is characterized by a wide range of signs and symptoms that affect numerous human systems and organs. This disease causes neurological issues, including encephalopathy, recurrent epilepsy, intellectual disability, ataxia, and involuntary movements. The initial step of the mitochondrial respiratory chain, during which protons are transported across the inner mitochondrial membrane along with electron transfer from NADH to ubiquinone, is catalyzed by NADH: ubiquinone oxidoreductase. In this case report, we describe a patient presenting with severe, rapidly progressive neurological loss who harbored a novel mutation in NDUFAF2 identified using exome sequencing. At six months of age, her mother noticed delayed motor development. Thereafter, the patient developed metabolic acidosis and abnormal movements, mimicking seizures triggered by aspiration pneumonia, with elevated serum lactate levels. Genetic testing revealed a c.127G>A mutation in NDUFAF2, consistent with mitochondrial complex I deficiency. This case highlights the utility of exome sequencing as a powerful and cost-effective tool for diagnosing clinically heterogeneous disorders such as mitochondrial diseases. Mitochondrial complex I deficiency is an important differential diagnosis in patients with recurrent central hypoventilation. Our findings expand the mutational spectrum of this rare disease.

Keywords: case report; episodic respiratory failure; mitochondrial complex i deficiency; ndufaf2; recurrent encephalopathy

DOI: https://doi.org/10.7759/cureus.86670

BMJ Case Rep. 2025 Jul 18. pii: e266155. [Epub ahead of print]18(7):

NDUFV1 mutation presenting as isolated progressive optic neuropathy: a unique manifestation of mitochondrial complex I deficiency.

Parul Mittal, Samendra Karkhur, Vidhya Verma, Priti Singh.

Mutations in the NDUFV1 gene, encoding a subunit of mitochondrial complex I, are typically associated with severe neurological disorders such as Leigh syndrome. We report a pre-teen girl with progressive bilateral optic atrophy and steady visual deterioration, without neurological findings or systemic involvement. Neuroimaging was unremarkable for white matter lesions or structural brain lesions. Whole-exome sequencing demonstrated a homozygous missense mutation (c.1156C>T, p. Arg386Cys) in NDUFV1, implying a nuclear-encoded complex I defect. Laboratory analysis revealed increased lactate levels, consistent with mitochondrial dysfunction. Despite treatment with coenzyme Q, riboflavin and idebenone, no significant visual improvement occurred. This case represents a novel phenotype of NDUFV1-associated disease isolated optic atrophy without systemic involvement expanding the clinical spectrum of NDUFV1 mutations. Recognising this unique mitochondrial optic neuropathy may aid early diagnosis and targeted management.

Keywords: Genetics; Neuroimaging; Neuroopthalmology; Retina; Visual pathway

DOI: https://doi.org/10.1136/bcr-2025-266155

Cell Chem Biol. 2025 Jul 17. pii: S2451-9456(25)00201-6. [Epub ahead of print]32(7): 902-904

Powering the powerhouse: Mitochondrial NADPH propels oxidative metabolism.

Riley J Wedan, Sara M Nowinski.

Mitochondrial NADPH is abundant, but the reason why was uncertain. In a study published in Nature Cell Biology, Kim et al.1 identified an important role of NADK2-derived mitochondrial NADPH in mitochondrial fatty acid synthesis (mtFAS) through direct quantification of the products built by mtFAS. This work opens the door to understanding how NADK2, mitochondrial NADPH, and mtFAS regulate mitochondrial function.

DOI: https://doi.org/10.1016/j.chembiol.2025.06.006

Cancer Res Commun. 2025 Jul 23.

One-Carbon Metabolism Inhibition Depletes Purines and Results in Profound and Prolonged Ewing Sarcoma Growth Suppression.

Sara Zirpoli, Noah Copperman, Shrey Patel, Alexander Forrest, Zhanjun Hou, Larry H Matherly, David M Loeb, Antonio Di Cristofano.

Ewing sarcoma (EWS) is the second most common primary bone malignancy in adolescents and young adults. Patients who present with localized disease have experienced a steadily improving survival rate over the years, whereas those who present with metastatic disease have the same dismal prognosis as 30 years ago, with long term survival rates less than 20%, despite maximal intensification of chemotherapy. Thus, novel treatment approaches are a significant unmet clinical need. Targeting metabolic differences between EWS and normal cells offers a promising approach to improve outcomes for these patients. One-carbon metabolism utilizes serine and folate to generate glycine and tetrahydrofolate (THF)-bound one-carbon units required for de novo nucleotide biosynthesis. Elevated expression of several one-carbon metabolism genes is significantly associated with reduced survival in EWS patients. We show that both genetic and pharmacological inhibition of a key enzyme of the mitochondrial arm of the one-carbon metabolic pathway, serine hydroxymethyltransferase 2 (SHMT2), leads to substantial inhibition of EWS cell proliferation and colony-forming ability, and that this effect is primarily caused by depletion of glycine and one-carbon units required for synthesis of purine nucleotides. Inhibition of one-carbon metabolism at a different node, using the clinically relevant dihydrofolate reductase inhibitor Pralatrexate, similarly yields a profound growth inhibition, with depletion of thymidylate and purine nucleotides. Genetic depletion of SHMT2 dramatically impairs tumor growth in a xenograft model of EWS. Together, these data establish dependence on one-carbon metabolism as a novel and targetable vulnerability of EWS cells, which can be exploited for therapy.

DOI: https://doi.org/10.1158/2767-9764.CRC-25-0218