bims-polgdi Biomed News
on POLG disease
Issue of 2025–11–02
33 papers selected by
Luca Bolliger, lxBio



  1. Acta Neurol Belg. 2025 Oct 31.
      Mitochondrial DNA (mtDNA) maintenance defects (specifically mtDNA depletion syndromes, MDS) are autosomal recessive disorders caused by a severe reduction in mtDNA content, leading to impaired oxidative phosphorylation and energy deficiency in affected tissues. The clinical heterogeneity of mtDNA maintenance defects correlates with specific gene mutations, with POLG being one of the most frequently implicated genes in mitochondrial dysfunction. We report a novel case of mtDNA maintenance defects manifesting with progressive ocular symptoms, including blepharoptosis, blurred vision, and diplopia, associated with a rare homozygous POLG mutation (c.924G > T, p.Gln308His), which is the second reported homozygous variant at this nucleotide site. Among five previously reported POLG c.924G > T-associated MDS cases, 4 are heterozygous (compound heterozygous or combined with other mitochondrial gene variants). POLG encodes DNA polymerase γ, essential for mtDNA replication; mutations impair mitochondrial function, reducing respiratory chain activity and ATP production. This case adds to the existing literature on the phenotypic variability of POLG-related disorders and expands the known spectrum of pathogenic POLG variants. Despite the rarity of this mutation, its clinical presentation is consistent with classic progressive external ophthalmoplegia (PEO), underscoring the importance of genetic testing in diagnosing mtDNA maintenance defects. Further studies are needed to clarify genotype-phenotype correlations and develop targeted therapeutic strategies for POLG-associated mitochondrial dysfunction.
    Keywords:  DNA polymerase; Mitochondrial DNA (mtDNA) maintenance defects; Progressive external ophthalmoplegia (PEO); The POLG gene
    DOI:  https://doi.org/10.1007/s13760-025-02922-9
  2. Nat Commun. 2025 Oct 27. 16(1): 9448
      Mitochondria transfer is a spontaneous process that releases functional mitochondria to damaged cells via different mechanisms including extracellular vesicle containing mitochondria (EV-Mito) to restore mitochondrial functions. However, the limited EV-Mito yield makes it challenging to supply a sufficient quantity of functional mitochondria to damaged cells, hindering their application in mitochondrial diseases. Here, we show that the release of EV-Mito from mesenchymal stem cells (MSCs) is regulated by a calcium-dependent mechanism involving CD38 and IP3R signaling (CD38/IP3R/Ca2+ pathway). Activating this pathway through our non-viral gene engineering approach generates super donor MSCs which produce Super-EV-Mito with a threefold increase in yield compared to Ctrl-EV-Mito from normal MSCs. Leber's hereditary optic neuropathy (LHON), a classic mitochondrial disease caused by mtDNA mutations, is used as a proof-of-concept model. Super-EV-Mito rescues mtDNA defects and alleviates LHON-associated symptoms in LHON male mice. This strategy offers a promising avenue for enhancing mitochondria transfer efficiency and advancing its clinical application in mitochondrial disorders.
    DOI:  https://doi.org/10.1038/s41467-025-64486-9
  3. Pathogens. 2025 Oct 16. pii: 1045. [Epub ahead of print]14(10):
      We hypothesize that a unified mitochondrial perspective on aging, HIV, and long COVID reveals shared pathogenic mechanisms and specific therapeutic vulnerabilities that are overlooked when these conditions are treated independently. Mitochondrial dysfunction is increasingly recognized as a common factor driving aging, HIV, and long COVID. Shared mechanisms-including oxidative stress, impaired mitophagy and dynamics, mtDNA damage, and metabolic reprogramming-contribute to ongoing energy failure and chronic inflammation. Recent advancements highlight new therapeutic strategies such as mitochondrial transfer, transplantation, and genome-level correction of mtDNA variants, with early preclinical and clinical studies providing proof-of-concept. This review summarizes current evidence on mitochondrial changes across aging and post-viral syndromes, examines emerging organelle-based therapies, and discusses key challenges related to safety, durability, and translation.
    Keywords:  HIV; SARS-CoV-2; mitochondria
    DOI:  https://doi.org/10.3390/pathogens14101045
  4. Mol Genet Metab Rep. 2025 Dec;45 101266
      The F-box and leucine-rich repeat protein 4 (FBXL4) is a nuclear encoded mitochondrial protein essential for mitochondrial DNA (mtDNA) maintenance. Biallelic variants in FBXL4 cause FBXL4-related mitochondrial DNA depletion syndrome (FBXL4-MTDPS), characterized by lactic acidosis and developmental delay. We report two siblings diagnosed with FBXL4-MTDPS who died of fulminant pneumonia in infancy; autopsy revealed extensive pulmonary inflammation consistent with severe bacterial infection. FBXL4-MTDPS may involve intrinsic defects in pulmonary infection defense, increasing susceptibility to fatal infection such as pneumonia.
    Keywords:  Encephalomyopathic mitochondrial DNA depletion syndrome; F-box and leucine-rich repeat protein 4; Fatal fulminant pneumonia; Lactic acidosis; Mitophagy
    DOI:  https://doi.org/10.1016/j.ymgmr.2025.101266
  5. Front Cell Dev Biol. 2025 ;13 1677402
       Introduction: Mitochondria are integral components of eukaryotic cells, functioning as energy powerhouses and key mediators of diverse metabolic and signaling cascades. As endosymbiotic remnants, these unique organelles retain and express their own DNA. Mitochondrial DNA (mtDNA) is packaged into DNA-protein complexes called nucleoids, and is also subject to epigenetic modification. We identified a mitochondrial isoform of DNA methyltransferase 1 (mtDNMT1) that binds to mtDNA in critical control regions; however, its enzymatic activity remained unexplored.
    Results: Here, we show that endogenously-tagged mtDNMT1 purified from mitochondria exhibits time- and concentration-dependent CpG-specific DNA methyltransferase activity, but it is not working alone: DNMT3b cooperates with mtDNMT1 to methylate mtDNA and regulate mitochondrial transcription. In addition, we detect ten-eleven translocase (TET)-like hydroxymethylase activity in mitochondria, demonstrating that mechanisms for both writing and erasing 5-methylcytosine marks are functional in this organelle. CRISPR/Cas9-mediated inactivation of mtDNMT1 and/or DNMT3b activity resulted in a stepwise decrease in mitochondrial methylation across the heavy and light strand promoters of mtDNA, with a significant reduction in transcription of several mtDNA-encoded OXPHOS genes. Interestingly, the effects of mtDNA methylation on mitochondrial transcription are diametrically opposed to the role of promoter methylation in the nucleus, suggesting a novel mode of gene regulation in mitochondria. Cells lacking mtDNMT1 and/or DNMT3b also exhibited a modest reduction in mtDNA content, suggesting that methylation impacts both mtDNA transcription and replication.
    Discussion: These observations implicate mtDNA methylation in the fine-tuning of mitochondrial function and suggest a role for aberrant mitochondrial methylase activity in disease.
    Keywords:  DNA demethylation; DNA methylation; DNA methyltransferase; DNA replication; epigenetics; mitochondrial DNA (mtDNA); transcription
    DOI:  https://doi.org/10.3389/fcell.2025.1677402
  6. Mitochondrion. 2025 Oct 29. pii: S1567-7249(25)00090-X. [Epub ahead of print] 102093
      The recent development of mitochondrial base editors (mitoBEs) has ushered in a transformational time that has overcome some long-standing limitations in the field of mitochondrial genetics. By closely tracing mitoBE development from the earliest tool mitochondria targeted TALENs to the most recent base editing systems that can precisely convert C•G → T•A and A•T → G•C, we review mitoBEs. We describe the development of recent advancements in mitoBEs including the generation of second generation mitoBEs (mitoBEs v2), which have evidence to identify over 70 mouse mtDNA mutations comparable to human pathogenic variants. Notably, in order to incorporate circular RNA (circRNA) as a delivery vector the editing efficiency has been increased by over 82 %, without experimental evidence of off-target effects. Taking advantage of these gains in technology, these mouse models of mitochondrial diseases, including those associated with Leigh syndrome and LHN, are highly faithful. These models have also confirmed that these specific mtDNA variants have pathological phenotypic evaluations, and have compared to previous editing strategies, mitoBEs v2 have demonstrated improved specificity, stability and safety. We finally discuss the future of mitochondrial base editing and outline the ways it will move forward towards therapeutic potentials in the treatment of the mitochondrial disorders and also in precision medicine.
    Keywords:  ABE; CBE; Mitochondrial diseases; TALED; circRNA; mitoBEs; mtDNA
    DOI:  https://doi.org/10.1016/j.mito.2025.102093
  7. Anal Biochem. 2025 Oct 29. pii: S0003-2697(25)00243-X. [Epub ahead of print] 116004
      We present an optimised luminometric method for measuring muscle mitochondrial ATP production rate (MAPR), adapted to a 96-well microplate format. The enhanced assay enables quantification of ATP production from 12 or more substrate combinations within 15 minutes, using only 10 μL of isolated mitochondria. The method demonstrates high accuracy and precision, with a validated measurement range of 0.3-70 nmol/min/L. To support clinical interpretation, a reference dataset was established from 92 individuals aged seven months to 79 years. All these individuals were referred for muscle biopsy but were subsequently deemed unlikely to have a mitochondrial disorder following comprehensive clinical evaluation. An overview of the current version of our assays for oxidative phosphorylation (OXPHOS) enzymes is also provided. As proof of concept, we present three patients carrying pathogenic variants in mitochondrial DNA (ATP6 and MT-TL1) and the nuclear PDHA1 gene. All exhibited decreased MAPR with one or more substrates, along with additional clinical, biochemical, and morphological features consistent with mitochondrial disease. Furthermore, we illustrate the age-dependent development of MAPR in muscle across the human lifespan, demonstrating a 60-80% higher maximal capacity for oxidative ATP production in adults compared with young children. In contrast, MAPR supported by fatty acid-derived substrates remains unchanged over the same period. In conclusion, the improved MAPR assay offers a robust and efficient tool for assessing mitochondrial function in both clinical diagnostics and research. Its high-throughput format and reliable performance make it particularly well-suited for the investigation of suspected mitochondrial disorders.
    Keywords:  ATP; luciferase; mitochondria; muscle; oxidative phosphorylation; pyruvate
    DOI:  https://doi.org/10.1016/j.ab.2025.116004
  8. J Cell Sci. 2025 Oct 15. pii: jcs264320. [Epub ahead of print]138(20):
      For researchers and clinician-scientists, forging partnerships with patient-led rare disease organizations can be a challenge. Patient-led rare disease organizations often operate quite differently to research and medical institutions, large private or public funding organizations, and pharmaceutical or biotechnology companies, leaving researchers and clinician-scientists uncertain about how, when and where to engage for mutual benefit. However, the value of reciprocal engagement can be immense, paying dividends in new research directions, accelerating existing research, facilitating access to funding and achieving success in translation. Most importantly, it can improve the lives of individuals with disease. In this Perspective, we will explore the value of engaging and collaborating with patient-led rare disease organizations through the lens of a rare syndromic ciliopathy - Bardet-Biedl syndrome (BBS) - for which patient-led organizations exist in multiple countries. We explain what researchers should know about how rare disease organizations operate, discuss examples of successful engagement between researchers, clinician-scientists and patient-led organizations, and review the 'do's and don't's' of successful collaboration.
    Keywords:  Bardet–Biedl syndrome; Ciliopathies; Collaboration; Patient-led rare disease organization; Rare genetic diseases
    DOI:  https://doi.org/10.1242/jcs.264320
  9. Pharmacogenomics J. 2025 Oct 29. 25(6): 31
      It has been proposed that mitochondrial DNA variations can affect mitochondrial function, increasing the risk of drug-induced liver injury. This study aims to explore the association between mitochondrial DNA (mtDNA) variants and anti-tuberculosis drug-induced liver injury (ATT_DILI) in Korean tuberculosis patients. Whole mitochondrial genomes from 185 patients (61 with ATT_DILI and 124 without liver injury) were sequenced. Comparative analyses examined mtDNA variants, variant counts, and haplogroups between the two groups, adjusted with Bonferroni correction. The m.16189 T > C variant, associated with reduced mtDNA copy number, was more frequent in ATT_DILI cases (39.3%) than in controls (29.0%). Logistic regression suggested a potential association (odds ratio 4.92, 95% confidence interval 1.14-21.23, p = 0.033), though this significance was lost after correction. No significant differences in mtDNA variant counts or haplogroups were observed between groups. While mtDNA variants and haplogroups appear to have a limited role in predicting ATT_DILI risk, the m.16189 T > C variant warrants further investigation.
    DOI:  https://doi.org/10.1038/s41397-025-00390-1
  10. J Vis Exp. 2025 Oct 10.
      Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes (MELAS) are mitochondrial disorders most commonly caused by a m.3243A>G variant in mitochondrial tRNALeu. To investigate the pathophysiology of MELAS, we generated brain organoids from multiple induced pluripotent stem cell (iPSC) lines derived from a patient with MELAS carrying the m.3243A>G variant. These lines share an identical nuclear genetic background but differ in their heteroplasmy levels involving the m.3243A>G variant. We observed significant differences in organoid size, morphology, and neural induction efficiency, which correlated with the degree of heteroplasmy. Dissociated neurons from the organoids were transferred into a 2D-culture system, which is convenient and suitable for high-throughput drug screening. The organoids also exhibited significant differences in the formation of neural networks, depending on heteroplasmy levels. Our results suggest that patient-derived iPSC-based organoid models represent a useful platform for studying MELAS mechanisms and for drug screening. This video presents comprehensive and user-friendly methods, including protocols for generating organoids and evaluating phenotypes.
    DOI:  https://doi.org/10.3791/69303
  11. Redox Biol. 2025 Oct 17. pii: S2213-2317(25)00415-X. [Epub ahead of print]88 103902
      Mitochondrial transplantation is an upcoming therapeutic modality where transfer of healthy robust mitochondria bio-enhances metabolically dysfunctional cells or tissues. Though the concept of MT germinated in early 1980s in a bid to develop antibiotic resistance between cells, this innovative treatment has since undergone various breakthroughs in addressing metabolic dysfunction in various systemic diseases. Four decades since its advent, MT is now being applied in the field of Ophthalmology, where metabolic disorders affecting various ocular tissues contribute significantly to disease pathogenesis. Encouraged by the success of MT in other organs such as heart, lung and brain, this therapy has recently been applied to ocular disorders. MT is an emerging ocular therapy, with promising therapeutic outcomes for corneal, optic nerve, and retinal disorders. However, before it can be adopted as a "bench to bedside" therapy for ocular disorders, MT faces several potential bottlenecks. This review provides an overview of mitochondrial biology in eye diseases, summarizes the current state-of-the-art in ocular MT, whilst discussing challenges and future direction of bringing MT into clinical practice.
    Keywords:  Bioenergetic rescue; Clinical translation; Mitochondria transplantation; Mitochondrial biology; Ocular metabolic diseases; Oxidative stress
    DOI:  https://doi.org/10.1016/j.redox.2025.103902
  12. Biomolecules. 2025 Sep 28. pii: 1379. [Epub ahead of print]15(10):
      Mitochondria are crucial for a wide range of cellular processes. One of the most important is innate immunity regulation. Apart from functioning as a signaling hub in immune reactions, mitochondrial nucleic acids can themselves act as damage-associated molecular patterns (DAMPs) to participate in immune processes directly. This review synthesizes the current understanding of mitochondrial RNA (mtRNA) biology and its link to immune activation through aberrant accumulation. We focus on its origin through bidirectional mitochondrial transcription and metabolism, encompassing maturation (cleavage, polyadenylation, modification) and degradation. Dysregulation of mtRNA metabolism leads to mt-dsRNA (mitochondrial double-stranded RNA) accumulation, which escapes mitochondria via specific channels into the cytosol and serves as DAMPs to trigger an immune response. We discuss the critical roles of key regulatory factors, including PNPT1 (PNPase, Polyribonucleotide Nucleotidyltrans ferase 1), in controlling mt-dsRNA levels and preventing inappropriate immune activation. Finally, we review the implications of mt-dsRNA-driven inflammation in human diseases, including autoimmune disorders, cellular senescence, and viral infection pathologies, highlighting unresolved questions regarding mt-dsRNA release mechanisms.
    Keywords:  degradation; immune responds; maturation; mitochondrial RNA; transcription
    DOI:  https://doi.org/10.3390/biom15101379
  13. J Patient Rep Outcomes. 2025 Oct 27. 9(1): 127
       BACKGROUND AND OBJECTIVES: Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) is a rare genetic syndrome mostly associated with pathogenic variants in mitochondrial DNA. As there is limited research on the life experience of patients with MELAS, this study aimed to develop an understanding of the patient experience of MELAS through qualitative interviews to identify, describe, and substantiate important and relevant signs, symptoms, and health-related quality-of-life (HRQoL) impact (S/S/I) concepts.
    METHODS: Clinician and patient interviews were conducted virtually using semi-structured interview guides. During 60-minute interviews with five experts in the United States, clinicians were asked for their perspective on S/S/I of patients with MELAS, patient experience of fatigue and cognitive impairment, and whether patients would be able to accurately report and rate their symptoms and complete a 90-minute patient experience interview. During a 45-minute interview conducted with 16 adults with confirmed pathogenic variant and clinical diagnosis of MELAS, patients were asked about S/S/I. Interviews were recorded, transcribed, anonymized, coded, and analyzed for saturation and concept frequency and clarification (e.g., severity, frequency, duration).
    RESULTS: Experts reported 44 distinct S/S and 36 HRQoL impact concepts. All five experts confirmed that cognitive impairment would not inhibit a typical patient's ability to report on their own experiences; three reported that patients with MELAS would not be able to complete a 90-minute interview. Sixteen patient interviews (mean age: 42.3 [11.1], n = 10 women) were conducted. Interviews with patients with MELAS achieved saturation of concept and yielded 35 S/S concepts and 68 HRQoL impacts across 15 domains. The most frequently reported S/S concepts were physical fatigue (n = 15, 93.8%), hearing loss (n = 13, 81.3%), mental fatigue (n = 12, 75.0%), and exercise intolerance and memory problems (n = 11, 68.8% each). The most frequently reported impact domains were adaptive behaviors and work impacts (n = 14, 87.5% each) and emotional function (n = 13, 81.3%).
    DISCUSSION: Patients with MELAS can self-report on S/S/I. Results from both patient and clinician interviews demonstrate that symptoms related to fatigue and cognitive impairment are frequent, bothersome, and important to improve. Assessments of fatigue and cognitive function should therefore be considered key outcome measures in clinical trials enrolling patients with MELAS.
    Keywords:  Concept elicitation; MELAS; Mitochondrial disease; Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes; Patient-centered outcomes; Qualitative interviews
    DOI:  https://doi.org/10.1186/s41687-025-00962-6
  14. Cells. 2025 Oct 17. pii: 1621. [Epub ahead of print]14(20):
      Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality worldwide and is attributed to complex pathophysiological mechanisms that surpass the traditional risk factors. Emerging evidence indicates that mitochondrial dysfunction plays a central role in CVD progression, linking impaired bioenergetics, oxidative stress imbalance, and defective mitochondrial quality control to endothelial dysfunction, myocardial injury, and adverse cardiac remodeling. However, the mechanistic interplay between mitochondrial dysfunction and CVD pathogenesis remains unclear. This review provides a comprehensive synthesis of recent knowledge, focusing on the dysregulation of mitochondrial energy metabolism, alterations in mitochondrial membrane potential, and disruptions in mitochondrial dynamics, including the balance of fusion and fission, mitophagy, and biogenesis. Furthermore, we critically evaluated emerging mitochondria-targeted therapeutic strategies, including pharmacological agents, gene therapies, and regenerative approaches. By bridging fundamental mitochondrial biology with clinical cardiology, this review underscores the critical translational challenges and opportunities in developing mitochondria-focused interventions. A deeper understanding of the mitochondrial mechanisms in CVD pathophysiology will offer novel diagnostic biomarkers and precision-targeted therapeutics, thereby transforming CVD management.
    Keywords:  cardiovascular disease; mitochondria dynamics; mitochondrial dysfunction; mitophagy; oxidative stress; targeted therapy
    DOI:  https://doi.org/10.3390/cells14201621
  15. J Xenobiot. 2025 Oct 18. pii: 170. [Epub ahead of print]15(5):
      Mitochondria play crucial roles in various cellular functions, including ATP production, apoptosis, and calcium homeostasis. Signaling pathways and hormones such as estrogens regulate the mitochondrial network through genetic, epigenetic, and metabolic processes. Estrogens increase the efficiency of mitochondrial oxidative phosphorylation by preventing uncoupling. Upon reaching menopause, when estrogen levels decrease, impaired mitochondrial function (uncoupled oxidative phosphorylation, lower ATP yields) is observed. Like all hormones in the body, estrogens undergo metabolic processing, resulting in estrogenic degradation metabolites (EDMs). These metabolites can form adducts with genomic and mitochondrial DNA and are of particular interest due to their potential role as carcinogens. Given that estradiol influences mitochondrial function, it is possible that EDMs may have an impact on heart mitochondria. To investigate this, we used isolated heart mitochondria from control and oophorectomized (mimicking menopausal stage) female Wistar rats of the same age. We found that mitochondria exposed to EDMs exhibited reduced coupling of oxidative phosphorylation and diminished ATP production, while increasing reactive oxygen species generation. Furthermore, these effects were significantly stronger in mitochondria from oophorectomized rats than in mitochondria from control (intact) rats. In addition, mitochondrial oxidative phosphorylation complex activities were differentially affected: complex I and ATPase activities decreased, while complex IV remained unaffected. We propose that exposure to EDMs promotes mitochondrial dysfunction in rats and that these effects are exacerbated by oophorectomy, a procedure commonly used to model the effects of menopause in women.
    Keywords:  OXPHOS uncoupling; estrogen degradation metabolites; heart mitochondria; oophorectomy
    DOI:  https://doi.org/10.3390/jox15050170
  16. Viruses. 2025 Sep 30. pii: 1331. [Epub ahead of print]17(10):
      Gemykibivirus, an emerging single-stranded DNA (ssDNA) virus of the recently established genus in the family of Genomoviridae, had been discovered in human blood and cerebrospinal fluid and a variety of other body fluids. However, the molecular mechanisms of gemykibivirus entrance into the host cells and its pathogenicity remain poorly understood. To investigate the host response of gemykibivirus, we used an infectious clone of gemykibivirus previously established through molecular biology techniques to rescue virus in HEK293T cells and analyzed the changes in the host transcriptome during the infection period by RNA-Seq. Our findings indicate that gemykibivirus can both express viral proteins and accomplish replication, and high-throughput transcriptome analysis identified a total 1732 significantly different genes. Functional enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for differentially expressed genes (DEGs) showed gemykibivirus involving several important pathways, including MAPK signaling pathway, Chemical carcinogenesis-reactive oxygen species and Oxidative phosphorylation. Interestingly, mitochondrial DNA-encoded mRNAs exhibited varying levels of upregulation, suggesting that gemykibivirus may be involved in mitochondrial fission and the regulation of mitochondrial function. Subsequently, a series of experiments proved that gemykibivirus can lead an increase in mitochondrial DNA copy number, promote the release of mtDNA into the cytoplasm, enhance reactive oxygen species production and trigger other cellular antiviral responses. Overall, we lay a foundation for revealing the relationship between Gemykibivirus and human diseases through mitochondrial functional alterations.
    Keywords:  Genomoviridae; RNA sequencing; emerging viruses; gemykibivirus; mitochondrial dysfunction
    DOI:  https://doi.org/10.3390/v17101331
  17. Alzheimers Dement. 2025 Oct;21(10): e70839
       INTRODUCTION: Mitochondrial DNA (mtDNA) variation may influence cognitive performance, but prior findings are inconsistent.
    METHODS: We analyzed data from 2308 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study, assessing heteroplasmy (mtHz) burden and haplogroups (mtHg) from blood-derived mtDNA at three timepoints and cognitive function across multiple domains. Multivariate linear regression models and multivariate linear mixed models adjusted for age, sex, education, and race.
    RESULTS: MtDNA heteroplasmy burden and count were not associated with cognitive performance. However, mtHgs in macro-mtHg L were linked to poorer cognitive outcomes, particularly in processing speed and global cognition in cross-sectional and longitudinal analyses. Associations remained significant after adjusting for social determinants of health (SDOH) or APOE ε4, comorbidities, and lifestyle variables.
    DISCUSSION: The mtDNA variation, especially mtHgs, may play a role in influencing cognitive trajectories, warranting further research on its role in cognitive aging.
    HIGHLIGHTS: Heteroplasmy burden was not associated with cognitive performance at midlife. Haplogroups were associated with cognitive outcomes at midlife. Longitudinal analysis revealed that haplogroups are associated with cognitive trajectories.
    Keywords:  cognitive function; midlife; mitochondria; mitochondrial DNA; mitochondrial haplogroup; mitochondrial heteroplasmy
    DOI:  https://doi.org/10.1002/alz.70839
  18. PLoS Genet. 2025 Oct 27. 21(10): e1011923
      Telomerase Reverse Transcriptase (TERT), in addition to its well-known role in telomere lengthening, also has non-canonical functions, including gene regulation and protection against apoptosis. Beyond its nuclear functions, it is now recognized for its presence inside mitochondria. However, the biological role of TERT in mitochondrial physiological activity, with its specific mechanism of action, still needs to be clarified. This work clearly demonstrates the presence of TERT inside the mitochondrion under physiological conditions, in different cellular contexts, both with endogenous and ectopic TERT expression, and regardless of the presence of telomerase RNA counterpart TERC. TERT was shown to bind mitochondrial DNA, influencing mitochondrial replication and transcription. Furthermore, electron microscopy analysis of morphology revealed TERT-induced fragmentation of the mitochondrial network. Collectively, our findings suggest that TERT may play a role in regulating mitochondrial biogenesis and dynamics, and influencing processes such as fission and mitophagy, essential for maintaining mitochondrial homeostasis and closely connected to cellular states.
    DOI:  https://doi.org/10.1371/journal.pgen.1011923
  19. Int J Mol Sci. 2025 Oct 11. pii: 9885. [Epub ahead of print]26(20):
      Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) closely interacts with host cellular mechanisms, with mitochondria playing a crucial role in this process. As essential organelles that control cellular energy production, apoptosis, reactive oxygen species (ROS) metabolism, and innate immune responses, mitochondria are vital to the development of COVID-19. However, the exact molecular interactions between mitochondria and SARS-CoV-2 remain under active investigation. Gaining a comprehensive understanding of mitochondrial involvement in SARS-CoV-2 infection is therefore essential for uncovering complex disease mechanisms, identifying prognostic biomarkers, and developing effective treatments. Ultimately, exploring these virus-host interactions may provide new insights into the fundamental and complex aspects of mitochondrial physiology and pathophysiology.
    Keywords:  ROS; SARS-CoV-2; biomarkers; diagnosis; inflammasome activation (e.g., NLRP3); interactoma; long COVID; mitochondria; mitochondrial antiviral signaling (MAVS); mitochondrial bioenergetics; mitochondrial damage-associated molecular patterns (mtDAMPs); mitochondrial disease; mitochondrial fission/fusion dynamics; mitophagy; oxidative phosphorylation; oxidative stress; prognosis; viral immune evasion
    DOI:  https://doi.org/10.3390/ijms26209885
  20. Curr Stem Cell Res Ther. 2025 ;20(7): 713-718
      Mesenchymal stem cells (MSCs) are adult stem cells with immunoregulatory abilities and low immunogenicity, exhibiting powerful immunosuppressive effects in various inflammatory diseases and holding promise for therapeutic applications. However, the detailed underlying mechanisms remain unclear. Multiple studies suggest that the immunomodulatory function of MSCs is primarily based on the release of immunoregulatory factors through paracrine effects, contributing to their therapeutic outcomes. Other studies report that the immunosuppressive effects of MSCs are mainly achieved through apoptosis, mitochondrial transfer, and the newly proposed migrasomes, highlighting their potential clinical implications. We propose a novel hypothesis, suggesting that migrasomes released by MSCs play a pivotal role in their immunomodulatory ability, potentially offering new avenues for therapeutic interventions. This article primarily summarizes the possible mechanisms by which MSCs exert their immunomodulatory effects, focusing on MSC apoptosis, mitochondrial transfer, and migrasomes, with implications for developing novel therapeutic strategies.
    Keywords:  Mesenchymal stem cells; apoptosis; macrophages; migrasomes.; mitochondrial transfer; phosphatidylserine
    DOI:  https://doi.org/10.2174/011574888X320528240826054546
  21. Pharmaceutics. 2025 Sep 23. pii: 1242. [Epub ahead of print]17(10):
      Neurological-related diseases are among the most debilitating and difficult to manage. Many possible pharmacological treatments for neurological diseases struggle to cross the blood-brain barrier (BBB) to achieve concentrations that can produce a therapeutic benefit. This is primarily because of the existence of the BBB, which poses significant hurdles for both therapeutic and diagnostic efforts by restricting the entry of most medications. Nasal-to-brain drug transportation has surfaced as an encouraging approach to tackle the difficulties linked with conventional drug administration techniques for neurological disorders. In response, innovative methods for improving drug delivery focus on breaking down the BBB via physical techniques, including optical and photothermal therapy, electrical stimulation, and acoustic or mechanical stimulation. Nanocarriers represent a promising approach for facilitating nasal systemic and brain delivery of active compounds. Hence, the achievement of therapeutically relevant concentrations of exogenous molecules within the body is significantly contingent upon the nanocarriers' capability to surpass biological barriers. Polymers in nanocarrier formulations can result in significantly enhanced nose-to-brain drug delivery by protecting drugs from premature biodegradation, increasing permeability, improving mucoadhesion, and targeting specific cells in the brain. Polymeric nanocarriers are frequently functionalized with cell-penetrating peptides to further improve the specificity of the loaded therapeutic molecules. This review focuses on the use of nanocarrier-based therapeutic agents to enhance the efficacy of nose-to-brain delivery systems.
    Keywords:  Alzheimer’s disease; HIV; Parkinson’s and Huntington’s disease; blood–brain barrier; cancer; nanocarriers; polymers
    DOI:  https://doi.org/10.3390/pharmaceutics17101242
  22. Curr Opin Neurobiol. 2025 Oct 30. pii: S0959-4388(25)00163-1. [Epub ahead of print]95 103132
      Since their discovery and development, human induced pluripotent stem cells (iPSCs) have brought about notable advances in biomedical science and have become an essential infrastructure for medical research and applications. This review discusses the current status of iPSC-based cell therapies, drug discovery, and therapeutic developments for neurodegenerative diseases with unmet medical needs. It also highlights research approaches employing cohorts of iPSCs derived from sporadic neurodegenerative diseases to advance prevention and diagnostic support. It further considers future directions for the use of iPSCs in the treatment of neurodegenerative disorders.
    DOI:  https://doi.org/10.1016/j.conb.2025.103132
  23. AAPS PharmSciTech. 2025 Oct 30. 27(1): 9
      Parkinson's disease (PD) is a common progressive neurodegenerative condition involving the degeneration of dopaminergic neurons and the accumulation of misfolded α-synuclein protein. Although standard pharmacotherapies such as levodopa provide symptomatic improvement, their effectiveness is usually compromised by issues with low bioavailability, short half-life, and limited penetration of the blood-brain barrier (BBB). Nanotechnology provides a revolutionary answer by allowing more targeted drug delivery to the brain. A broad range of nanocarriers such as liposomes, polymeric nanoparticles, and micelles have demonstrated excellent potential to enhance drug stability, target specificity, and BBB penetration. In addition, these nanocarriers can be used to deliver gene-based therapeutics and nutraceuticals in a targeted manner, potentially providing the ability to directly impact underlying pathological processes like oxidative stress, mitochondrial dysfunction, and neuroinflammation. This review emphasizes the most recent developments in the use of nanotechnology for PD management, addressing the design, therapeutic significance, and translational problems of these systems. By increasing delivery accuracy and facilitating disease modification, nanocarrier-based systems have the potential to lead the way in more effective and tailored treatments for Parkinson's disease.
    Keywords:  Parkinson disease; conventional treatments; genes; nanocarriers; nutraceuticals; pathogenesis
    DOI:  https://doi.org/10.1208/s12249-025-03234-0
  24. Sci Rep. 2025 Oct 28. 15(1): 37679
      Whole genome sequencing (WGS) comprehensively detects DNA sequence variation, enabling assessment of genetic disorders. The primary aim of this study was to investigate the diagnostic utility of WGS for pediatric musculoskeletal disorders by comparing it with whole exome sequencing (WES), which is more widely used but not as comprehensive in its coverage of the genome. This multi-center cohort study consists of WGS and WES analysis for 36 pediatric patients with musculoskeletal disorders of unknown etiology and, where available, their parents and siblings. WGS and WES were performed on DNA extracted from saliva samples. Secondary analysis of sequence data and tertiary analysis with interpretation of sequence variants were performed using the Illumina DRAGEN and Emedgene platforms, respectively. We evaluated 36 patients, and the median age was 11 years. The most common phenotypes included thoracolumbar scoliosis and gait disturbance. The median number of candidate variants per patient identified by WES and WGS were 57.5 and 90.5, respectively. 38 pathogenic or likely pathogenic variants were identified by WGS, providing a potentially diagnostic (tier-1) candidate for 22 of 36 (61.1%) patients. 12 of the 38 tier-1 variants (31.6%) were identified only by WGS. Of these 12 variants missed by WES, two candidates had variants that are likely to solve the respective case after undergoing manual curation. WGS resulted in a larger number of variants predicted as pathogenic/likely pathogenic in patients with musculoskeletal phenotypes, including variants potentially capable of solving their respective cases. WGS showed particular advantage in detecting CNVs. This study demonstrates that WGS is a promising method for improving our understanding of musculoskeletal disorders marked by genetic and phenotypic heterogeneity.
    Keywords:  CNV; Genomics; Musculoskeletal; Pediatric; Rare disease; SNV; Tertiary analysis; Variant interpretation; WGS; Whole-genome sequencing
    DOI:  https://doi.org/10.1038/s41598-025-21421-8
  25. Forensic Sci Int Genet. 2025 Oct 28. pii: S1872-4973(25)00162-0. [Epub ahead of print]81 103382
      Mitochondrial DNA (mtDNA) plays a crucial role in forensics and population genetics, especially for analysing highly degraded samples. Yet, most mitogenomic reference datasets are still limited to control region (CR) sequences, that have limited discriminatory power. This is particularly true for Belgium, where despite the introduction of new legislation in 2024 to increase the use of mitochondrial DNA in familial searching, comprehensive mitogenomic reference data remain scarce. To fill this gap, we present a new forensic-grade dataset comprising complete mitochondrial genomes from 264 individuals with maternal ancestry from Flanders, the northern part of Belgium. Maternal lineages were verified through validated genealogical records extending prior to 1750. Our Flemish dataset reveals 252 unique haplotypes, a mean pairwise difference of 27.3, and a random match probability of 0.0042, demonstrating forensic resolution comparable to other high-quality European datasets. Haplogroups H, U, and T predominate in Flanders, aligning with broadly observed European patterns, while clustering analyses show close genetic affinities with neighbouring Western European populations. Furthermore, comparison with ancient genomes from the Middle Ages reveals notable continuity in maternal ancestry in Flanders throughout the historical era. Our data substantially expand the mitochondrial reference for Flanders, providing a high-quality resource based on autochthonous maternal lineages, suitable for forensic applications, genetic genealogical analyses, and microgeographic population studies.
    Keywords:  Ancient DNA; Flanders; Genetic genealogy; Mitochondrial DNA; Whole genome sequencing
    DOI:  https://doi.org/10.1016/j.fsigen.2025.103382
  26. Chin Med J (Engl). 2025 Oct 31.
       ABSTRACT: Mitochondria serve as multifunctional powerhouses within cells, coordinating essential biological activities that are critical for cell viability, including material metabolism, signal transduction, and the maintenance of homeostasis. They support cells in adapting to complex and fluctuating environments. Oocytes, being the largest cells in multicellular organisms, contain a high number of mitochondria with unique structural characteristics. Mitochondria play active roles in the development and maturation of oocytes. A decline in mitochondrial function negatively affects both the quality and quantity of oocytes, thereby contributing to ovarian aging. However, the specific mechanisms through which mitochondrial dysfunction influences the progression of ovarian aging and impacts reproductive longevity remain unclear. Furthermore, medical strategies aimed at rejuvenating mitochondria to restore ovarian reserve and improve female reproductive potential may open new avenues for clinical treatment. In this review, we summarize the current understanding and key evidence regarding the role of mitochondrial dysfunction in ovarian aging and present emerging medical approaches targeting mitochondria to alleviate premature ovarian aging and enhance reproductive performance.
    Keywords:  Mitochondrial dysfunction; Mitochondrial replacement treatment; Ovarian aging; Stem cell transplantation; Traditional Chinese Medicine
    DOI:  https://doi.org/10.1097/CM9.0000000000003801
  27. Genes Dev. 2025 Oct 29.
      Mitochondria play a crucial role in cellular energy metabolism and homeostasis and are strongly implicated in aging and age-related diseases. The outer mitochondrial membrane protein voltage-dependent anion channel (VDAC) plays multiple roles in mitochondrial homeostasis, including transport of metabolites, ATP, and Ca2+ Dysregulation of VDAC levels has been associated with cancer, neurodegeneration, metabolic disorders, and aging. Previously, we demonstrated that elevated VDAC-1 levels in Caenorhabditis elegans lead to increased mitochondrial permeability and reduced life span. Here we demonstrate that reduced VDAC-1 function extends life span through the activation of the mitochondrial unfolded protein response (UPRmt), a conserved stress response that maintains mitochondrial proteostasis and is linked to life span extension in multiple species. Leveraging unbiased genomic discovery, we identified genes encoding several proteins in the PeBoW complex as a critical mediator of UPRmt activation following VDAC-1 loss. More broadly, we demonstrated a universal requirement for several PeBoW component genes across diverse mitochondrial stressors in order to fully animate the UPRmt Our findings reveal a heretofore unappreciated role for PeBoW components in UPRmt induction and life span extension in response to mitochondrial stress, highlighting its essential function in mitochondrial quality control and longevity pathways.
    Keywords:  PeBoW; mito-stress; mitoUPR; mitochondria
    DOI:  https://doi.org/10.1101/gad.352979.125
  28. J Extracell Biol. 2025 Nov;4(11): e70093
      Extracellular vesicles (EVs) have gained increasing attention in recent years due to their pivotal role in both health and disease. Emerging from both eukaryotic and prokaryotic cells, EVs serve as essential mediators of intercellular communication, exceeding the simplistic interactions observed with individual molecules. In this comprehensive review, we will focus on both Bacterial Extracellular Vesicles (BEV) and on Host derived Extracellular Vesicles (HEV) and highlight mechanistic principles, as well as their transformation into diagnostic and therapeutic tools. We will start with a short introduction into the biogenesis and principal properties of BEV and HEV. We will then focus on the composition of BEV and introduce OMICs-based studies that helped to unravel their complex constitution. As both BEV and HEV interact with different epithelial and endothelial barriers and shape their properties, we will highlight mechanistic principles for both EV types. Starting from the intestinal system, where we will look at BEV and how these BEV overcome the intestinal barrier to change distant organs and the patient's immune system. We will then visit other endothelial and epithelial sites of the human body and summarize how HEV shapes these barriers and how HEV can overcome these barriers. We will then turn towards diagnostic and therapeutic approaches. As both BEV and HEV are currently suggested as diagnostic markers and are being investigated as potential therapeutic agents. Lastly, we will discuss current challenges and provide an outlook on the future in the field. This review seeks to raise awareness for both bacterial and host-derived EVs, highlighting that they present two sides of the same coin.
    DOI:  https://doi.org/10.1002/jex2.70093
  29. J Evol Biol. 2025 Oct 27. pii: voaf130. [Epub ahead of print]
      Aerobic respiration in mitochondria is the source for most of the energy that powers complex animals, and maintaining energy flow from mitochondria near the optimum needed for life processes presents challenges for complex animals. Environments of most animals change rapidly. Moreover, individuals pass through developmental stages with different energy demands, and they shift life history states that require modified production of ATP. To adjust to changing conditions, all complex animals display some capacity for acclimatization through phenotypic flexibility, whereby key aspects of mitochondrial respiration are reversibly altered. Phenotypic flexibility is a universal feature of the energy-production mechanisms of animals, but all animals face limitations in the range of environments and circumstances to which they can acclimatize. We discuss multiple examples of such phenotypic flexibility in animals, focusing on the different mechanisms employed that acclimatize mitochondrial respiration to exogenous and endogenous challenges. Genotype sets the range of phenotypes related to mitochondrial respiration that is available to an animal. Numerous studies document adaptive evolution of both mitochondrial and nuclear genes that directly affect the range of environments that will support oxidative phosphorylation. Phenotypic flexibility can obscure evolutionary changes in response to changing energy demands, and understanding the interplay of capacity for acclimatization and adaptive evolution of mitochondrial systems presents major challenges for physiological and evolutionary biologists.
    DOI:  https://doi.org/10.1093/jeb/voaf130
  30. Children (Basel). 2025 Oct 10. pii: 1369. [Epub ahead of print]12(10):
      Background/Objectives: Cord blood mitochondrial DNA copy number (mtDNAcn) has been proposed as a biomarker reflecting environmental influences during fetal life, with reported associations with perinatal outcomes such as birth weight and length. Within the framework of the Developmental Origins of Health and Disease (DOHaD) theory, this study aimed to investigate whether cord blood mtDNAcn is related to postnatal physical growth in early childhood. Methods: We analyzed data from 150 newborns (68 females and 82 males) enrolled in the Tohoku Medical Megabank Birth and Three-Generation Cohort Study in Japan. Cord blood mtDNAcn was quantified using real-time PCR, and standard deviation scores for weight and height were assessed at 1, 2-3, 4-6, 18-24, and 36-48 months of age. Correlation analyses were conducted separately by sex. Results: Cord blood mtDNAcn showed no significant associations with body weight or height at any of the postnatal time points up to 48 months of age. Growth trajectories of infants with higher or lower mtDNAcn values at birth tended to converge toward the population mean during infancy and toddlerhood. Conclusions: Although no significant relationships were observed, this exploratory, hypothesis-generating study provides a foundation for future investigations. Larger cohorts with extended follow-up are needed to clarify the potential significance of cord blood mtDNAcn in early-life research on child growth and health.
    Keywords:  DNA copy number variation; DOHaD; cord blood; mitochondrial DNA; physical growth
    DOI:  https://doi.org/10.3390/children12101369
  31. Cells. 2025 Oct 11. pii: 1585. [Epub ahead of print]14(20):
      Adenosine plays a crucial role in various pathophysiological conditions, including neuroinflammation and neurodegeneration. Neuroinflammation can be either beneficial or detrimental to the central nervous system, depending on the intensity and duration of the inflammatory response. Across a wide range of brain disorders, neuroinflammation contributes to both the onset and progression of disease. Notably, neuroinflammation is not limited to conditions primarily classified as neuroinflammatory but is also a key factor in other neurological disorders, including life-threatening neurodegenerative diseases. All four adenosine receptor subtypes (A1, A2A, A2B, and A3) are implicated, to varying degrees, in these conditions. This review aims to summarize the roles of individual adenosine receptor subtypes in neuroinflammation and neurodegenerative diseases, emphasizing their therapeutic potential. While some therapeutic applications are well-established with clinically approved drugs, others warrant further investigation due to their promising potential.
    Keywords:  Alzheimer’s disease; Amyotrophic lateral sclerosis; GPCR; Huntington’s disease; Parkinson’s disease; adenosine; adenosine receptors; caffeine; neurodegenerative diseases; neuroinflammation; purinergic system
    DOI:  https://doi.org/10.3390/cells14201585
  32. BMJ Open. 2025 Oct 27. 15(10): e105045
       BACKGROUND: The vast majority of healthcare research in the UK is investigator-led. While national progress in patient and public involvement (PPI) increasingly mandates patient consultation, research questions and outcomes still frequently misalign with patient priorities. This is particularly important in rare disease research, as more than 95% of 11 000 conditions have no effective or curative treatment, and around 20% are not clinically defined, making them difficult to diagnose and manage. The unmet physical, mental and emotional needs of people living with rare diseases are immense. Extensive guidance and toolkits exist to support investigators with PPI, but none target patient communities attempting to promote their own priorities, initiate or co-lead research.
    AIM: This communication article introduces the newly established patient-led Rare Disease Research Network (RDRN). WHAT IS THE RDRN, AND HOW CAN IT BE USEFUL?: Launched in November 2024, the RDRN is an open-access collaborative platform designed to support patient-driven and co-produced research, connecting patient and professional partners with similar research interests. Originally conceived by an ultra-rare patient group, the network was co-produced with the rare disease community, including individuals living with rare conditions, parents, carers and charity advocates, whose lived experience and priorities shaped every aspect of its design. Supported by academic and research networks, its collaborative development ensures RDRN removes barriers to participation while complementing existing initiatives. RDRN is a novel approach to driving new impactful research by aligning investigator priorities with real-world needs and building capacity from patients outward. Rare disease communities bring lived expertise, creativity and motivation. Yet without a structured route to collaborate, their insights are often lost. RDRN offers an inclusive space, fostering new partnerships and supporting upstream collaboration. The approach enables patients to become 'research ready' and empowers them to have an active role in generating ideas and delivering research from inception, leading to innovative research and driving meaningful change in patients' lives. With further development, RDRN could present a lasting, scalable and unified model for co-designed rare disease research. By enabling trust, capacity and shared purpose, it can drive discovery, improve outcomes and build a more resilient and self-sustaining research ecosystem, underpinning key pillars of the 2021 UK Rare Diseases Framework.
    Keywords:  Community-Based Participatory Research; Digital Technology; Health Equity; Organisational development; Patient Participation; Rare Diseases
    DOI:  https://doi.org/10.1136/bmjopen-2025-105045
  33. Pharmaceuticals (Basel). 2025 Sep 25. pii: 1443. [Epub ahead of print]18(10):
      Background: The human mitochondrial ClpP is a serine protease located in the mitochondrial matrix responsible for degrading short lived regulatory proteins as well as misfolded or damaged proteins, thereby maintaining cellular homeostasis. Proteastasis dysregulation is linked to tumor progression. Methods: We conducted a literature review (2020-2025) using PubMed and Scopus, focusing on studies addressing ClpP structure, function, activity modulation, and cancer relevance. Keywords included "ClpP", "ClpP activators", "ClpP inhibitors", and "mitochondrial protease". Results: ClpP is upregulated in many tumors compared to normal tissues. Cancer cells depend on ClpP for mitochondrial proteostasis, metabolic adaptation, and survival. ClpP proteolytic activity modulation-via activators or inhibitors-disrupts these processes showing efficacy even in clinical setting. Conclusions: ClpP is emerging as a key player in cancer pathophysiology and holds potential as a therapeutic target. Its selective overexpression in tumors, along with its involvement in mitochondrial homeostasis, makes it a compelling candidate for precision oncology.
    Keywords:  ClpP activators/inhibitors; ClpP overexpression; cancer; human ClpP protease; mitochondrial proteostasis; quality control system
    DOI:  https://doi.org/10.3390/ph18101443