bims-polgdi Biomed News
on POLG disease
Issue of 2026–08–02
forty-one papers selected by
Luca Bolliger, lxBio



  1. Genes (Basel). 2026 Jun 30. pii: 757. [Epub ahead of print]17(7):
      Background/Objectives: Patient registries are essential for rare disease research, yet the extensive genetic and phenotypic heterogeneity of primary mitochondrial diseases (PMDs) makes traditional registry development slow and resource-intensive. We established the MSeqDR PMD virtual registry (PMD-VR) to address this gap through systematic literature mining and semi-automated data harmonization. Methods: The PMD-VR captures, standardizes, and harmonizes published case-level PMD data using a semi-automated curation pipeline. A data transformation framework maps heterogeneous raw data terms to standardized common data elements (CDEs). A generative AI (GenAI) platform leveraging large language models (LLMs), augmented by Human Phenotype Ontology (HPO) and external biomedical knowledge sources, accelerates data transformation and generates simulated clinical reports. Results: Currently, PMD-VR contains approximately 11,000 de-identified literature-derived cases, including over 2300 Leigh syndrome spectrum (LSS), 278 MELAS, and 300 CPEO cases. The pipeline mapped 872 heterogeneous terms to 102 standardized CDEs. Pathogenicity assessments were captured for variants in over 7900 cases, including 3800 with mtDNA pathogenic or likely pathogenic variants. Modes of inheritance were inferred for 5212 cases. PMD-VR has supported ClinGen Mitochondrial Diseases Gene Curation Expert Panel (Mito-GCEP) efforts, providing phenotyped evidence for 440 curated LSS cases across 113 PMD genes. Conclusions: PMD-VR is among the largest single PMD registries, offering a scalable, web-accessible platform for generating analysis-ready cohorts from the published literature. It represents a rich resource enabling comprehensive PMD characterization with unprecedented breadth of genetic and phenotypic knowledge.
    Keywords:  Generative AI (GenAI); Leigh syndrome spectrum (LSS); human phenotype ontology (HPO); large language model; literature mining; mitochondrial disease; rare disease
    DOI:  https://doi.org/10.3390/genes17070757
  2. Int J Mol Sci. 2026 Jul 09. pii: 6128. [Epub ahead of print]27(14):
      Mitochondrial genetic disorders compromise oxidative phosphorylation (OXPHOS) and cellular energy supply, and the eye is among the first organs to feel the deficit. Photoreceptors and retinal ganglion cells (RGCs) sustain among the highest metabolic rates in the body, so ophthalmic features often dominate the clinical picture and arrive before systemic disease is recognized. More than half of all patients with confirmed mitochondrial disease develop sight-threatening complications. This review integrates mtDNA and nuclear genetics; ophthalmic and extraocular phenotypes; the bioenergetic and apoptotic mechanisms that drive vision loss; the clinical examination and investigations that delineate the problem; the differential diagnoses that must be excluded; the contribution of common mtDNA haplogroup variation to age-related retinal disease; and the diagnostic, therapeutic, and counseling approaches that turn a molecular result into useful care. Recurring themes are heteroplasmy, the threshold effect, and the selective vulnerability of RGCs and extraocular muscle across genetically distinct disorders. Treatment remains largely supportive, but idebenone, gene therapy, mitophagy modulation, and targeted antioxidants now offer mechanism-based intervention for several ophthalmic manifestations.
    Keywords:  clinical management; diseases; genetics; mitochondria; ophthalmology; oxidative stress
    DOI:  https://doi.org/10.3390/ijms27146128
  3. Biomolecules. 2026 Jul 01. pii: 972. [Epub ahead of print]16(7):
      Chronological age tells us how long a person has lived-but not how well. Two individuals of the same age can differ dramatically in their cellular health, disease risk, and functional capacity. This gap between calendar age and biological age has driven growing interest in biomarkers that reflect true cellular aging rather than years lived. Mitochondria sit at the heart of this problem. Far more than cellular power plants, these organelles govern energy production, oxidative stress, immune signaling, and programmed cell death. As the body ages, mitochondria deteriorate in consistent and measurable ways-and crucially, these changes can be detected in circulating blood cells, offering a minimally invasive window into the body's biological age. This narrative review synthesizes two decades of research (2005-2025) on three blood-based mitochondrial markers: mitochondrial DNA copy number (mtDNA-CN) in peripheral blood mononuclear cells, mitochondrial membrane potential (MMP), and cell-free mitochondrial DNA (cf-mtDNA) in plasma. Across 68 carefully selected studies, we evaluate the strength, consistency, and clinical relevance of each marker, alongside their associations with cardiovascular disease, metabolic dysfunction, cognitive decline, and mortality. The evidence is promising but still maturing. Significant methodological variation across studies limits direct comparisons, and robust prospective outcome data remain limited. We propose a four-phase framework for responsible clinical translation and identify specific research investments needed-from measurement standardization to large cohort studies and intervention trials-before these markers can responsibly inform patient care.
    Keywords:  aging biomarkers; biological aging; cell-free mitochondrial DNA; clinical translation; inflammaging; mitochondrial dysfunction; mitochondrial membrane potential; mtDNA copy number; oxidative stress; peripheral blood mononuclear cells
    DOI:  https://doi.org/10.3390/biom16070972
  4. J Clin Pharmacol. 2026 Aug;66(8): e70246
      Clinical drug development for rare diseases continues to face significant challenges due to disease heterogeneity, fewer available patients, and incomplete understanding of pathogenesis, resulting in trials with limited clinical data, thus constraining traditional development pathways. Clinical pharmacology, modeling, and simulation-based approaches can help address these challenges by informing decision-making, mitigating uncertainty, and guiding optimal dose and regimen selection for the appropriate patient population. These approaches help streamline trial designs by reducing the scope and number of clinical trial evaluations, using exposure-response analyses to optimize dosing, the use of mechanistic-physiologically based pharmacokinetics (M-PBPK)-based approaches for biopharmaceutical and formulation optimization, evaluations of drug-drug interactions, and organ impairment. These strategies increase development efficiency across all stages of drug development, thereby improving the probability of success. This review highlights case studies that applied innovative clinical and quantitative pharmacology approaches across early and late stages of drug development and regulatory decision-making in rare diseases. The specific examples illustrate the application of pharmacokinetics/pharmacodynamics (PK/PD) and model-informed drug development (MIDD) strategies to support dose and regimen selection, enabling efficient use of direct or adaptive trial designs, facilitating bridging across populations and indications, biopharmaceutics-based transitions, and generating integrated PK/PD evidence to support labeling. Examples include drug repurposing, characterizing PK/PD in early phase to inform late-phase development, population PK analysis to guide trial dosing and label recommendations, using phenotype-targeted study design to address disease heterogeneity, expanding dosing regimen across indications using MIDD, quantitatively evaluating immunogenicity to support mitigation strategies, biomarker bridging, and applying M-PBPK to predict clinical PK in organ impairment populations.
    Keywords:  MIDD; Rare Diseases; drug development
    DOI:  https://doi.org/10.1002/jcph.70246
  5. Signal Transduct Target Ther. 2026 Jul 29. pii: 295. [Epub ahead of print]11(1):
      Mitochondria are essential for cellular homeostasis, integrating various signals to control key cellular functions such as metabolism, apoptosis, inflammation, cell proliferation and redox balance. Given their multifaceted functions, it is not surprising that mitochondrial dysfunction has been implicated as a key contributor to the pathogenesis of numerous human diseases. Consequently, preserving mitochondrial integrity and functionality is vital for overall organismal health. Mitochondrial health is safeguarded by a sophisticated and tightly regulated network of quality control systems. These include mitochondrial proteostasis, which ensures proper protein folding and degradation; mitochondrial biogenesis, which governs the synthesis of new mitochondria; mitochondrial dynamics, encompassing fusion and fission processes; and mitophagy, the selective autophagic removal of damaged mitochondria. Additionally, these core systems are intricately connected to other crucial mitochondrial processes, such as the maintenance of mitochondrial DNA integrity, the regulation of cristae architecture, and the control of mitochondrial permeability transition, all of which are indispensable for optimal mitochondrial performance. Preclinical and clinical studies consistently demonstrate a strong link between impairments in these quality control mechanisms and both aging and the development of a wide spectrum of diseases. These include cancer, metabolic disorders, cardiovascular conditions, neurodegenerative diseases and autoimmune pathologies. In this review, we explore the different facets of mitochondrial quality control and discuss their implications in disease progression and aging. Furthermore, we highlight recent advances in interventions and therapies aimed at modulating mitochondrial quality control, providing an overview of their potential to mitigate disease burden and promote healthy aging.
    DOI:  https://doi.org/10.1038/s41392-026-02813-2
  6. Biomolecules. 2026 Jul 22. pii: 1072. [Epub ahead of print]16(7):
      Mitochondrial dysfunction is increasingly recognized as a major contributor to central nervous system (CNS) disorders, including neurodegenerative and neuropsychiatric diseases. Animal models are essential for elucidating disease mechanisms and supporting the development of new therapeutic strategies. Among these models, non-mammalian organisms offer distinct advantages, including low cost, rapid life cycles, genetic tractability, and suitability for large-scale, high-throughput studies. Organisms such as Saccharomyces cerevisiae, Dictyostelium discoideum, Caenorhabditis elegans, Drosophila melanogaster, and Danio rerio have substantially advanced the understanding of mitochondrial processes relevant to CNS pathology. Studies using these models have revealed conserved mechanisms involving mitophagy, mitochondrial quality control, respiratory function, bioenergetic signaling, and neurodegenerative pathways. Their strengths, including scalability, live imaging capacity, and efficient genetic manipulation, have accelerated disease modeling and therapeutic discovery. However, simplified physiology, evolutionary distance from humans, and the incomplete representation of complex CNS organization limit their translational relevance and often require validation in higher-order organisms. Nevertheless, integrating these models into CNS research, particularly alongside emerging technologies, provides a powerful strategy for linking fundamental mitochondrial biology with translational neuroscience. This review summarizes the use of non-mammalian models in neuroscience research, with an emphasis on mitochondrial dysfunction in CNS disorders and their potential to support future therapeutic advances.
    Keywords:  CNS disorders; Caenorhabditis elegans; Danio rerio; Dictyostelium discoideum; Drosophila melanogaster; Saccharomyces cerevisiae; mitochondria; non-mammalian models
    DOI:  https://doi.org/10.3390/biom16071072
  7. Genes (Basel). 2026 Jul 03. pii: 780. [Epub ahead of print]17(7):
      Rare genetic diseases are heterogeneous across mechanisms, trajectories, and treatment responses. To date, approved therapies remain available for only a small proportion of rare genetic diseases. Oligonucleotide-based RNA therapeutics, particularly antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs), offer a promising therapeutic avenue for rare genetic diseases with sequence-level precision. However, traditional preclinical paths may mis-predict human outcomes when disease biology diverges from animal models. New approach methodologies (NAMs), including patient-derived induced pluripotent stem cells (iPSCs), organoid models, and clinical-trials-in-a-dish (CTiD), aim to bring human biology earlier into the translational pipeline. NAMs enable variant-to-function studies, efficacy screening, and safety triage at clinically relevant speed and scale. While critics argue that NAMs are unvalidated and cannot replace preclinical animal models, proponents report that they are increasingly able to recapitulate human phenotypes and predict clinical liabilities, although their predictive validity remains context-dependent. Here, a front-loaded human filter refers to the use of human-derived systems early in development to support mechanistic interpretation, candidate prioritization, and early liability assessment before broader nonclinical evaluation. Recent studies pairing NAMs with ASOs support rapid, patient-specific preclinical screening in selected settings, while also showing the need for broader evidence on delivery, pharmacology, safety, and clinical relevance. This review places these developments within the translational realities of oligonucleotide-based therapeutics, including model fidelity, ASO chemistry and optimization, delivery challenges, pharmacology, regulatory pathways for individualized ASOs, and accessibility. We also propose a pragmatic validation framework to assess the scientific and translational credibility of NAMs across rare genetic diseases.
    Keywords:  RNA therapeutics; antisense oligonucleotides (ASOs); clinical-trials-in-a-dish (CTiD); engineered tissues; induced pluripotent stem cells (iPSCs); microphysiological systems; new approach methodologies (NAMs); pharmacokinetics/pharmacodynamics (PK/PD); rare genetic diseases; small interfering RNAs (siRNAs)
    DOI:  https://doi.org/10.3390/genes17070780
  8. J Am Med Inform Assoc. 2026 Jul 31. pii: ocag131. [Epub ahead of print]
       OBJECTIVES: Systematic clinical phenotyping using Human Phenotype Ontology (HPO) is central to rare disease diagnosis. However, current disease prioritization (ranking candidate diseases from HPO for a patient) methods face key challenges: they often fail to account for the hierarchical structure of HPO terms, ignore dependencies among correlated terms, and do not adjust for batch effects arising from systematic differences in phenotype documentation across cohorts, institutions, or clinicians. We aim to develop a scalable and statistically principled framework to address these limitations for rare disease prediction and patient stratification.
    MATERIALS AND METHODS: We developed PhenoSS, a Gaussian copula-based framework that models disease-specific marginal prevalence of HPO terms while capturing their joint dependencies through a multivariate normal distribution. Phenotype frequencies were estimated using external curated resources, including OARD (Open Annotations for Rare Diseases) and HPO annotations. PhenoSS supports both pair-wise phenotype similarity calculation for patient clustering and posterior odds estimation for patient-specific disease prioritization. A batch-effect correction module mitigates systematic phenotyping differences across datasets.
    RESULTS: Across diverse simulation scenarios, PhenoSS demonstrated robust disease-prediction performance and consistently improved accuracy after batch-effect correction. In real electronic health record data, PhenoSS identified clinically meaningful patient clusters and effectively distinguished patients with different rare diseases. In disease prioritization tasks, PhenoSS achieved competitive performance with existing methods, particularly for patients exhibiting sparse or noisy phenotype annotations.
    CONCLUSION: PhenoSS provides a statistically interpretable framework for modeling phenotypic heterogeneity in rare disease research and is adaptable to other structured clinical vocabularies such as SNOMED-CT and ICD codes.
    Keywords:  Human Phenotype Ontology; electronic health record; patient clustering; rare disease; semantic similarity
    DOI:  https://doi.org/10.1093/jamia/ocag131
  9. Res Sq. 2026 Jul 22. pii: rs.3.rs-10117408. [Epub ahead of print]
      Mitochondria power brain function and cognition, yet no label-free, non-invasive method has existed to explore their relationship to ageing, disease, and cognition in humans. The MitoBrainMap framework predicts mitochondrial features from magnetic resonance data alone, potentially bridging cellular biology with macroscale brain organization. Here we tested whether it captures meaningful age- and disease-related variation across individuals. MR-predicted mitochondrial density and tissue respiratory capacity declined with age, whereas intrinsic mitochondrial respiratory capacity was relatively preserved. Correlations among predicted features matched known mitochondrial biology, supporting preliminary construct validity. In patients with genetically confirmed mitochondrial diseases, predicted maps revealed region-specific alterations, notably the expected compensatory upregulation of nuclear- encoded complex II. Predicted features were further associated with the energetic stress marker GDF15 and with cognitive performance, linking brain mitochondrial estimates to systemic physiology and behavior. These findings introduce a first-generation, label-free neuroimaging-based mitochondrial mapping as a non-invasive window into living human brain mitochondria.
    DOI:  https://doi.org/10.21203/rs.3.rs-10117408/v1
  10. Nature. 2026 Jul;655(8125): S11
      
    Keywords:  Diseases; Medical research; Nanoparticles; Nanoscience and technology
    DOI:  https://doi.org/10.1038/d41586-026-02182-4
  11. Ann Clin Transl Neurol. 2026 Jul 31.
       BACKGROUND: Primary mitochondrial disease is a group of genetic disorders caused by pathogenic variants in nuclear or mitochondrial DNA, often resulting in progressive neurodegeneration and cognitive decline. Current management is primarily supportive, though recent research offers hope for disease-modifying treatments in the future. Selecting appropriate therapeutic outcomes for clinical trials in mitochondrial diseases is challenging due to limited sensitivity to changes, small sample sizes, and the burden of study related activities. This study aims to identify an efficient choice of cognitive endpoints for translational research.
    METHODS: This study compared digital cognitive assessments with traditional paper-based tools. It included two cohorts: the Newcastle cohort of 45 patients recruited from the mitochondrial clinic Newcastle upon Tyne (UK) and the KHENERGYZE clinical trial cohort of 27 patients recruited from four European countries. Patients in the Newcastle cohort underwent two conventional cognitive assessments (Addenbrooke's Cognitive Examination and Montreal Cognitive Assessment), along with two computerized tests (Cogstate and Test of Attentional Performance). Potential confounding factors were also assessed.
    RESULTS: Both cohorts showed a high prevalence of moderate to severe perceived fatigue. Over 50% of patients showed reduced reaction times. Strong correlations were found between conventional and digital assessments. Several confounding factors such as education and employment were identified as influencing cognitive performance.
    CONCLUSIONS: The findings support the understanding of mitochondrial disease as a slowly progressive condition, where impaired cognitive function is evident even in patients in the absence of devastating CNS manifestations such as stroke-like episodes. Observed variability in cognitive performance may help detect meaningful changes over time.
    Keywords:  minimal clinically important differences; neurocognitive assessments; neurodegeneration; primary mitochondrial disease
    DOI:  https://doi.org/10.1002/acn3.70463
  12. J Clin Pharmacol. 2026 Aug;66(8): e70250
      Rare‑disease drug development is constrained by small and heterogeneous patient populations, limited natural‑history data, and the impracticality of large, randomized trials. Despite increasing regulatory acceptance of totality-of-evidence and mechanism-based development pathways, generating reliable, decision-ready evidence under these constraints remains challenging. This review describes how clinical pharmacology contributes within an evidence‑integration and decision‑support framework through quantitative, model‑informed approaches to address this gap. By integrating nonclinical data, pharmacokinetics, pharmacodynamics, biomarkers, natural‑history information, and clinical efficacy and safety outcomes, and through close collaboration with clinical, statistical, and translational experts, clinical pharmacology supports interpretation of treatment effects and quantitative characterization of uncertainty when conventional evidence is limited. In practice, these approaches inform key development decisions, including dose selection, innovative trial designs, extrapolation and bridging across populations, use of external controls, and evaluation of biomarkers and surrogate endpoints. Importantly, such practices help align regulatory expectations with patient needs, particularly in pediatric and ultra‑rare settings, by enabling appropriate dosing, reduced trial and patient burden, and quantitative assessment of benefit/risk. Examples from rare‑disease programs illustrate how integrated quantitative evidence has supported regulatory decisions, including label expansion and accelerated approval when data may be sparse, heterogeneous, or evolving. Looking ahead, emerging technologies such as artificial intelligence, digital biomarkers, and individualized approaches are expected to further advance rare‑disease drug development. With this evolving landscape, clinical pharmacology is expected to continue playing an important role in evaluating mechanistic plausibility, ensuring analytic rigor, and translating small datasets into meaningful evidence to inform development and regulatory decisions in rare diseases.
    Keywords:  benefit‐risk; clinical pharmacology; external controls; extrapolation; model‐informed drug development (MIDD); rare diseases
    DOI:  https://doi.org/10.1002/jcph.70250
  13. Antioxidants (Basel). 2026 Jun 30. pii: 830. [Epub ahead of print]15(7):
       BACKGROUND: Mitochondria are the primary organelles that regulate cellular bioenergetic metabolism and maintain homeostasis, providing essential structural support for optimal cell survival. Nonetheless, advancing age leads to cumulative damage to mitochondrial structure and functional integrity, which is a defining characteristic of biological aging and is closely linked to the emergence and progression of numerous age-related diseases, including neurodegenerative disorders, cardiovascular diseases, and metabolic disorders.
    SCOPE OF REVIEW: This article offers a thorough summary and review of mitochondrial quality control (MQC), emphasizing numerous critical processes, including mitochondrial biosynthesis, dynamic remodeling (fusion and fission), and mitophagy. We thoroughly elucidate the molecular pathways that regulate MQC and demonstrate how age-related dysregulation precipitates cellular senescence, highlighting the transition from physiological maintenance to pathological malfunction, which ultimately culminates in cellular aging.
    CONCLUSIONS AND IMPLICATIONS: This study systematically elaborates the pathophysiological mechanisms in the field, comprehensively evaluates the clinical translational potential of targeting the MQC pathway, highlights the key objectives of "restoring mitochondrial plasticity and removing dysfunctional mitochondria", and explores novel intervention strategies. The restoration of normal mitochondrial function in cells throughout aging is a very promising path for precision medicine therapeutics with great translational potential, according to recent state-of-the-art research. The development of novel therapeutic approaches to improve functional healthy mitochondria can effectively delay aging and reduce the rising global burden of age-related diseases.
    Keywords:  age-related diseases; cellular senescence; metabolic homeostasis; mitochondrial quality control; mitophagy; therapeutic targets
    DOI:  https://doi.org/10.3390/antiox15070830
  14. Curr Issues Mol Biol. 2026 Jun 23. pii: 645. [Epub ahead of print]48(7):
      The second most prevalent neurodegenerative illness in the world, Parkinson's disease (PD), currently has no viable treatments. Although it is yet unknown if mitochondrial dysfunction is an initial event or evolves as a result of neurodegeneration, it is thought to be a crucial component of Parkinson's disease etiology. From the perspective of mitochondrial quality control (MQC), which includes PINK1/Parkin-mediated mitophagy, mitochondrial dynamics, and mitochondrial proteostasis, this article examines mitochondrial dysfunction. Together, these processes preserve mitochondrial homeostasis and prevent the buildup of damaged mitochondria. Dysfunctional mitochondria gradually build up and cause oxidative stress and aberrant cellular signaling when mitochondrial quality control is compromised. According to available data, mitochondrial reactive oxygen species (mtROS) primarily worsen pre-existing mitochondrial damage by encouraging α-synuclein aggregation, cardiolipin remodeling, and dopamine oxidation. In addition, innate immune pathways like cGAS-STING and TLR9 signaling can be triggered by mitochondrial damage-associated molecular patterns (mtDAMPs), especially mitochondrial DNA, which can lead to long-term neuroinflammatory reactions in PD. While new research suggests that m6A RNA modification may be involved in the regulation of mitochondrial stress, the PINK1/Parkin pathway is crucial for maintaining mitochondrial homeostasis. Therapeutic approaches that target mitophagy augmentation, neuroinflammatory signaling, and mitochondrial protection have garnered increasing attention. In an attempt to improve mitochondrial function and lessen persistent neuroinflammatory activation, future research will probably need to concentrate on combination treatment techniques.
    Keywords:  PINK1/Parkin pathway; Parkinson’s disease; m6A modification; mitochondrial malfunction; neuroinflammation; oxidative stress; therapeutic target
    DOI:  https://doi.org/10.3390/cimb48070645
  15. Autophagy. 2026 Jul 31.
      Mitochondrial quality control is essential for cellular homeostasis, particularly in neurons, where mitochondrial dysfunction is implicated in the pathogenesis of neurodegenerative diseases. Mitophagy, the selective degradation of damaged or superfluous mitochondria, plays a central role in maintaining mitochondrial integrity and metabolic balance. This review provides a comprehensive overview of the best-characterized PINK1-PRKN/parkin-dependent mitophagy pathway and the expanding repertoire of PRKN-independent mechanisms, including additional ubiquitin-dependent, receptor-mediated, and lipid-mediated pathways. We explore how these pathways intersect and compensate for one another, highlighting the complexity and adaptability of mitochondrial quality control networks. Furthermore, we discuss how dysregulated mitophagy contributes to the onset and progression of neurodegenerative diseases. By examining the interplay between mitophagy pathways and their regulation under physiological and pathological conditions, this review underscores the therapeutic potential of targeting mitophagy in neurodegeneration. Future studies should aim to decode the spatiotemporal dynamics of these pathways to uncover novel opportunities for clinical intervention.
    Keywords:  Autophagy receptors; E3 ubiquitin ligases; PINK-PRKN/parkin pathway; PRKN-independent mitophagy; mitochondrial dysfunction; mitochondrial quality control; mitophagy; neurodegeneration; therapeutic targets
    DOI:  https://doi.org/10.1080/15548627.2026.2711596
  16. Front Sociol. 2026 ;11 1810602
      This paper explores the social phenomenon of rare diseases through a logical-modal analysis. Although rare diseases originate within a biomedical framework and are increasingly recognised by institutional and empirical literature as issues of equity, inclusion, care and participation, this recognition has not usually been formalised in Durkheimian terms. The study applies modal logic, based on possible-worlds semantics and Kripke models, to clarify the conditions under which rare diseases acquire the status of social facts. By modelling behavioural change, coercion, generality and existence independent of individual manifestations, it shows how rare diseases transcend isolated clinical cases and impose structured constraints on social roles, families, institutions and policies. Empirical illustrations from international policy, employment studies, caregiver research and participation surveys are used to anchor the modal variables without treating the model as a statistical validation. The analysis argues that the transition from fragmented recognition to consolidated social fact depends on collective action, institutionalisation and normative recognition. The formalisation identifies intermediate configurations and a stabilised threshold state in which rare diseases become durable and socially binding within the model.
    Keywords:  Durkheim; institutionalization; modal logic; policies of recognition; rare diseases; social facts
    DOI:  https://doi.org/10.3389/fsoc.2026.1810602
  17. Antioxidants (Basel). 2026 Jun 25. pii: 793. [Epub ahead of print]15(7):
      Mitochondrial Lon peptidase 1 (LONP1) is an ATP-dependent AAA+ (ATPases associated with diverse cellular activities) protease that has emerged as a key regulator of mitochondrial proteostasis, with functions extending beyond protein quality control. In addition to degrading misfolded and oxidized proteins, LONP1 coordinates mitochondrial DNA maintenance, metabolic remodeling, and stress-responsive signaling. Recent structural and functional advances have expanded the biological significance of LONP1 beyond protein quality control, highlighting its roles in mitochondrial metabolism, genome maintenance, and stress responses. LONP1 dysregulation is increasingly implicated in cancer, metabolic disorders, neurodegeneration, and aging, where it exerts context-dependent effects on cell survival and disease progression. In cancer, LONP1 supports metabolic plasticity, redox adaptation, and therapeutic resistance, whereas in degenerative conditions, its decline contributes to mitochondrial dysfunction and tissue damage. Here, we synthesize recent insights into the structure, mechanisms, and biological functions of LONP1 and discuss their implications for human disease. We further discuss emerging therapeutic strategies and key challenges for targeting LONP1 in human disease.
    Keywords:  LONP1; cancer metabolism; mitochondrial metabolism; mitochondrial proteostasis; stress response
    DOI:  https://doi.org/10.3390/antiox15070793
  18. Biomedicines. 2026 Jul 07. pii: 1521. [Epub ahead of print]14(7):
      Mitochondria play a vital role in fundamental cellular processes, serving as key regulators of energy metabolism, apoptosis, oxidative stress, calcium homeostasis. Mitochondrial dysfunction is widely regarded as a common pathogenic pathway in the development of widespread chronic diseases, such as metabolic disorders, cardiovascular disease, neurodegeneration, and malignancies. Modern research examines mitochondrial dynamics, mitophagy, mitochondrial biogenesis, mtDNA damage, and the role of reactive oxygen species not only for in-depth understanding of disease pathogenesis but also for identifying diagnostic markers and therapeutic targets. Determining mitochondrial dysfunction is a significant challenge and should involve a comprehensive approach with reliable assessment methods that take into account the dynamic state, number, and localization of mitochondria. The review summarizes the results of the studies exploring the pathogenetic role of mitochondrial dysfunction in the development of widespread chronic diseases and current methods of its evaluation for the integration of mitochondrial dysfunction biomarkers into modern diagnostic strategies and development of mitochondria-target treatment approaches.
    Keywords:  cardiovascular disease; flow cytometry; metabolic syndrome; mitochondrial dysfunction; mtDNA; neurodegenerative diseases; oncology; seahorse assay; transcriptome analysis
    DOI:  https://doi.org/10.3390/biomedicines14071521
  19. Ther Innov Regul Sci. 2026 Jul 29.
       BACKGROUND: For slowly progressive ultra-rare diseases, hard clinical endpoints such as mortality or sustained functional decline are often impractical within feasible trial timeframes. Surrogate biomarkers, including fluid and imaging analytes, offer a pathway to accelerate drug development. Achieving cross-jurisdictional regulatory acceptance for these surrogates remains a profound scientific and policy challenge.
    METHODS: We conducted a narrative synthesis incorporating regulatory guidance documents from the FDA, EMA, and NMPA, alongside PubMed-indexed literature on surrogate endpoint validation, orphan drug approval, and biomarker qualification programs published up to early 2026.
    RESULTS: The FDA's Accelerated Approval pathway and the EMA's Conditional Marketing Authorization represent the primary regulatory vehicles for surrogate-based approvals. A four-tier validation model is proposed, incorporating mechanistic plausibility, epidemiological association, quantitative surrogacy statistics, and confirmatory post-approval requirements. Case studies from neurology (spinal muscular atrophy) and metabolic disorders (lysosomal storage diseases) illustrate the context-of-use dependency of these surrogates. Cross-jurisdictional divergence in evidentiary standards and the absence of a dedicated ICH guideline for rare disease surrogate endpoints constitute major structural gaps.
    CONCLUSIONS: A globally harmonized evidentiary framework for surrogate endpoint qualification in ultra-rare diseases is urgently needed. Validating this framework in the ultra-rare space could serve as a stepping stone for broader rare disease drug development. Bayesian adaptive designs, international consortium registries, and real-world evidence frameworks are key enabling strategies for addressing the inherent sample-size constraints of this research.
    Keywords:  Accelerated approval; Biomarker; Health policy; Regulatory science; Surrogate endpoint; Ultra-rare disease
    DOI:  https://doi.org/10.1007/s43441-026-01026-7
  20. Metabolites. 2026 Jul 11. pii: 489. [Epub ahead of print]16(7):
       BACKGROUND/OBJECTIVES: Metabolic-dysfunction-associated steatotic liver disease (MASLD) and metabolic-dysfunction-associated steatohepatitis (MASH) arise in the setting of obesity, insulin resistance, type 2 diabetes, and metabolic syndrome. This review examines how mitochondrial dysfunction participates in the transition from lipid accumulation to hepatocyte injury, inflammation, and fibrosis, and how evidence from human, animal, and in vitro studies should be interpreted.
    METHODS: We provide a narrative synthesis of mechanistic, translational, and clinical studies on hepatic mitochondrial metabolism, fatty acid oxidation, oxidative phosphorylation, redox stress, organelle crosstalk, mitophagy, mitochondrial biogenesis and proteostasis, mitochondrial danger signals, the gut-liver-mitochondria axis, and mitochondria-related therapeutic strategies.
    RESULTS: In early metabolic overload, mitochondrial oxidation may increase as an adaptive response. With persistent substrate pressure, this adaptation can become inefficient, with impaired fatty acid disposal, less efficient oxidative phosphorylation, reactive oxygen species production, redox imbalance, defective mitochondrial quality control, altered mitochondrial biogenesis, mitochondrial unfolded protein response (UPRmt)-related proteostatic stress and mtDNA instability. Mitochondrial DNA and RNA released from damaged organelles may also activate cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING), inflammasome, and RNA-sensing pathways, linking hepatocyte stress to macrophage activation, stellate cell activation, extracellular matrix deposition, and fibrosis.
    CONCLUSIONS: The current evidence supports mitochondria as a stage-dependent amplifier of metabolic liver injury rather than a uniform initiating event. Clinically, the strongest evidence remains with upstream metabolic unloading and liver-directed metabolic therapy, whereas direct mitochondrial restoration and quality-control targeting remain promising but less mature.
    Keywords:  MASH; MASLD; fibrosis; insulin resistance; metabolic syndrome; metabolomics; mitochondrial dysfunction; mitochondrial quality control; mitophagy; oxidative stress
    DOI:  https://doi.org/10.3390/metabo16070489
  21. Biomed Res Int. 2026 ;2026(1): e6918118
      Reactive oxygen species (ROS) are highly reactive molecules generated through endogenous metabolic pathways and exogenous environmental exposures. While essential for physiological processes-including cell signaling, proliferation, differentiation, immune defense, and neurotransmission-dysregulated ROS production contributes to oxidative stress and widespread biomolecular damage. This review outlines the major enzymatic and non-enzymatic mechanisms of ROS formation, emphasizing mitochondrial electron leakage, NADPH oxidase activity, and metal-catalyzed reactions. It further explores the impact of cold exposure, physical exercise, nutritional imbalance, and aging on ROS levels through alterations in mitochondrial function, calcium signaling, and antioxidant defenses. While ROS are vital for certain biological activities, the article also emphasizes their destructive potential. Particular attention is given to the vulnerability of mitochondrial DNA (mtDNA) and nuclear DNA to hydroxyl radical attack, resulting in base modifications, sugar lesions, tandem lesions, and DNA-protein cross-links. These lesions disrupt replication fidelity, impair DNA repair, and promote mutagenesis, ultimately threatening genomic stability. Finally, apoptosis is described as being modulated by ROS in a dose-dependent manner through the intrinsic, extrinsic, and ER-stress pathways, with the central role of p53 in determining cell fate being highlighted. Collectively, this review integrates current knowledge on ROS generation, physiological functions, stress-induced dysregulation, and the molecular mechanisms underlying oxidative damage, offering a comprehensive perspective on their implications for genomic integrity and disease development.
    Keywords:  ROS; aging; apoptosis; mitochondrial dysfunction; oxidative lesions; oxidative stress
    DOI:  https://doi.org/10.1155/bmri/6918118
  22. iScience. 2026 Aug 21. 29(8): 116791
      Age-associated organ dysfunction markedly impairs quality of life and increases mortality in older adults. Aging frequently results in compromised mitochondrial function in organs with high energy demands, such as skeletal muscle, the brain, heart, kidneys, and liver. This impairment leads to excessive production of reactive oxygen species, increased inflammation, energy deficits, and aberrant cellular signaling, collectively fostering cellular senescence, and chronic diseases. Empirical research has demonstrated that regular physical exercise preserves mitochondrial integrity. This review summarizes common and specific responses to exercise in mitochondrial regulation across various organs and provides a comprehensive cross-organ analysis. The objective was to elucidate the molecular mechanisms through which exercise confers anti-aging effects and mitigates degenerative functional decline by restoring mitochondrial homeostasis. This review provides a theoretical foundation for developing targeted anti-aging interventions and for attenuating aging in multiple organs through lifestyle modifications.
    DOI:  https://doi.org/10.1016/j.isci.2026.116791
  23. BMJ Open. 2026 Jul 28. 16(7): e108748
       OBJECTIVES: To evaluate the regulatory approval, epidemiology, clinical benefits and pricing of orphan drugs approved by the National Medical Products Administration (NMPA) in China.
    DESIGN: Cross-sectional analysis.
    STUDY SAMPLE: Orphan drugs approved by the NMPA for rare disease indications between 1 January 2005 and 31 December 2022.
    OUTCOME MEASURES: The outcomes included regulatory approval lag time, National Reimbursement Drug List (NRDL) coverage, monthly treatment costs, clinical benefit (SMR, Service Médical Rendu) and additional therapeutic value (ASMR, Amélioration du Service Médical Rendu) ratings from the French National Health Authority (HAS, Haute Autorité de santé). Data were analysed at the drug indication level. The approval time lag was defined as the interval between the earliest global marketing authorisation and subsequent approval by China's NMPA.
    RESULTS: A total of 59 orphan drugs were approved by the NMPA for 32 rare disease indications in 2005-2022. Of the 24 indications with epidemiological data, the incidence ranged from 0.098 to 9.62 cases per 100 000 persons and the prevalence ranged from 0.017 to 25.7 cases per 100 000 population. A total of 51 drug-indication pairs had SMR ratings: 40 (63.5%) were rated as important, 2 (3.2%) as moderate, 6 (9.5%) as weak and 5 (7.9%) as insufficient. For the 61 indications with pricing data, the median annual treatment price was US$18 259.8 (IQR: US$6504.6 to US$184 011.9), while negotiated drugs, those included in the NRDL through price negotiation, had significantly lower prices than non-negotiated drugs (US$13 677.8 vs US$62 870.0, p=0.015). The ASMR ratings indicated that 5 (7.9%) were rated as important (II), 10 (15.9%) as moderate (III), 11 (17.5%) as minor (IV), and 25 (39.7%) as no improvement (V).
    CONCLUSIONS: The orphan drug policy in China has improved access to and affordability of orphan drugs, particularly through priority reviews and NRDL price negotiations. However, substantial barriers remain in accessing orphan drugs, including limited definitions of rare diseases, the unavailability of overseas-approved orphan drugs and the high costs of non-NRDL drugs. Therefore, 'Three Medical Linkage' healthcare reform, which integrates health insurance, medical service delivery and pharmaceutical regulation, should continue to incentivise the development of orphan drugs and improve patient accessibility and affordability.
    Keywords:  Drug Therapy; Health policy; Rare Diseases
    DOI:  https://doi.org/10.1136/bmjopen-2025-108748
  24. Orphanet J Rare Dis. 2026 Jul 31. pii: 260. [Epub ahead of print]21(1):
       BACKGROUND: Rare diseases affect a small percentage of the population but collectively impact millions worldwide. In the Middle East, the challenges are intensified by regional factors such as high rates of consanguinity, sociocultural stigma, limited diagnostic capacity, and inadequate healthcare infrastructure. These challenges often lead to delayed diagnoses, restricted access to treatment, and poor quality of life for affected individuals and their families.
    METHODS: The Rare Advocacy Council conducted two 1.5-hour virtual expert panels involving 14 regional and international stakeholders (5 clinicians, 4 patient advocates, and 5 international academic experts) to identify and prioritize the challenges of managing rare diseases in the Middle East region. Discussions were organized across four domains: disease recognition and diagnosis, the patient journey and continuum of care, access to timely diagnostics, and access to adequate treatment, followed by structured online voting (involving only clinicians and patient advocates; n = 9), discussions focused on prioritization, and a descriptive follow-up survey to identify the most critical barriers and propose actionable solutions.
    RESULTS: Key challenges identified included the lack of national disease registries, limited public awareness, underrepresentation of patient voices in decision-making, fragmented multidisciplinary care, and restricted access to diagnostics and advanced therapies. Top priorities included developing national registries, enhancing media-driven education, strengthening collaboration among care providers, and improving treatment accessibility through policy reforms.
    CONCLUSIONS: Effective management of rare diseases in the Middle East requires a coordinated, patient-centered approach. Strengthening health system infrastructure, investing in education, and aligning policy with patient needs are essential for sustainable improvement. Collaborative action among policymakers, healthcare providers, and advocacy groups can significantly advance care delivery and improve outcomes for individuals living with rare diseases.
    Keywords:  Diagnosis and treatment access; Healthcare policy; Middle East; Multidisciplinary care; Patient advocacy; Rare diseases
    DOI:  https://doi.org/10.1186/s13023-026-04469-1
  25. Front Immunol. 2026 ;17 1875468
      Skeletal muscle functions not only as a mechanical apparatus for locomotion but also serves as a pivotal metabolic hub and endocrine organ essential for systemic homeostasis. While traditional perspectives focused on macro-volumetric measurements, contemporary biology posits that muscle quality is fundamentally an integration of mechanotransduction, biochemical metabolism, and ultrastructural coupling. Under comorbidity conditions, the progressive decline of skeletal muscle is intricately linked to multi-systemic dysfunction. In chronic inflammatory environments, mechanical imbalance and metabolic derangements are not merely additive; instead, they construct a sophisticated "mechano-metabolic-immune" network by co-regulating immune cell phenotypes and inflammatory thresholds. Pathological remodeling represents the destabilization of this homeostatic axis: lipotoxic metabolic stress induces the phenotypic deviation of fibro-adipogenic progenitors (FAPs) and M1 polarization of macrophages, establishing a pro-inflammatory priming state. Furthermore, the leakage of mitochondrial DNA (mtDNA) resulting from impaired mitochondrial quality control amplifies local metabolic disturbances into cGAS-STING pathway activation that secondary drives macrophage M1 polarization, serving as a critical driver of muscle atrophy. Within this pathological context, mechanical signals act not only as physical stimuli but as active variables that remodel microenvironmental stability. Through molecular transducers such as Piezo1, FAK, and TRPV4, kinetic loading facilitates mechano-chemical transduction and activates the energy sensor AMPK, thereby maintaining mitochondrial dynamic equilibrium and suppressing inflammatory cascades. This metabolic remodeling promotes the transition of macrophages toward a pro-regenerative/anti-inflammatory phenotype, supporting functional maintenance by resolving chronic inflammation and restoring tissue homeostasis. This review proposes the "mechano-metabolic-immune" axis as a pivotal regulatory framework governing skeletal muscle quality. Given that the biological benefits of mechanical intervention are constrained by physiological thresholds, precisely defining exercise load parameters across diverse pathological backgrounds is a rational foundation for transitioning from macro-rehabilitation to mechanism-driven precision interventions targeting FAPs adipogenic differentiation, intramuscular fat accumulation, and AMPK-mediated mitochondrial quality control, providing essential criteria for developing safe and effective clinical exercise prescriptions.
    Keywords:  immunometabolism; lipotoxicity; mechanotransduction; mitochondrial homeostasis; precision exercise intervention; skeletal muscle quality
    DOI:  https://doi.org/10.3389/fimmu.2026.1875468
  26. Cells. 2026 Jul 09. pii: 1238. [Epub ahead of print]15(14):
      Copper is an essential trace element required for numerous enzymatic processes in the brain, including mitochondrial metabolism, antioxidant defense, and gene expression regulation. Recent studies have further implicated copper in a newly defined form of regulated cell death termed cuproptosis, providing a mechanistic framework for copper-dependent cytotoxicity. Increasing evidence indicates that copper dyshomeostasis is a common feature of major neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS), where it is associated with protein misfolding, redox imbalance, and neuronal vulnerability. Nevertheless, the mechanistic link between copper dysregulation and neuronal cell death remains incompletely defined. In this review, we systematically summarize the molecular mechanisms governing copper homeostasis and intracellular copper trafficking, while providing a timely, updated, and in-depth overview of the mechanistic basis and emerging biology of cuproptosis. We further comprehensively evaluate the current evidence linking copper dysregulation and cuproptosis-related pathways to neurodegenerative diseases, with particular emphasis on distinguishing mechanistic causation from pathological correlation. Importantly, we discuss current therapeutic strategies and emerging clinical efforts targeting copper metabolism, while highlighting the major challenges in defining the pathological significance and mechanistic contribution of cuproptosis in neurodegenerative diseases. Collectively, this review provides an updated framework for understanding the pathological significance and translational potential of cuproptosis in neurodegenerative diseases.
    Keywords:  Alzheimer’s disease; Parkinson’s disease; amyotrophic lateral sclerosis; copper homeostasis; cuproptosis
    DOI:  https://doi.org/10.3390/cells15141238
  27. Cancer Med. 2026 Aug;15(8): e72134
       BACKGROUND: Circulating mitochondrial DNA is being investigated as a liquid-biopsy biomarker because of its high copy number and release during cellular stress. However, diagnostic estimates vary across tumor types and assays, and prognostic studies have measured both cell-free mtDNA and cellular blood-derived mtDNA, which are not analytically equivalent. Non-malignant tissue injury and inflammation may also increase circulating mtDNA, limiting disease specificity.
    METHODS: Following PRISMA 2020 guidance, seven databases were searched through December 2025. Diagnostic analyses synthesized predominantly cell-free mtDNA assays, whereas prognostic analyses synthesized the circulating or blood-derived mtDNA measures reported by the original studies. Random-effects models were used to pool diagnostic indices and hazard ratios across 31 unique studies comprising 8334 patients with cancer and 1286 controls. The protocol was registered in PROSPERO (CRD420261301732).
    RESULTS: Predominantly cell-free mtDNA assays showed a pooled sensitivity of 0.73, specificity of 0.80, diagnostic odds ratio of 15.41, and area under the summary receiver operating characteristic curve of 0.845, with substantial between-study heterogeneity. The mtDNA-79 subgroup showed a sensitivity of 0.79, specificity of 0.93, and area under the curve of 0.909. Higher circulating or blood-derived mtDNA measures were associated with poorer overall survival (HR = 1.70, 95% CI: 1.42-2.03) and relapse-free survival (HR = 2.04, 95% CI: 1.71-2.44), but not with progression-free survival or mortality. MT-CYB-based measures showed a stronger adverse prognostic association than MT-ND1-based measures.
    CONCLUSIONS: Circulating mtDNA measures show diagnostic and prognostic associations across malignancies, but current evidence does not support stand-alone clinical use. Heterogeneity in specimen matrix, pre-analytical handling, assay definition, and disease-control selection requires standardized multicenter validation. mtDNA-79 and MT-CYB warrant further study, while total mtDNA abundance should be interpreted as a cancer-associated rather than cancer-specific signal unless combined with tumor-informed genomic or fragmentomic features.
    Keywords:  cell‐free mitochondrial DNA; circulating mitochondrial DNA; diagnostic accuracy; liquid biopsy; prognosis
    DOI:  https://doi.org/10.1002/cam4.72134
  28. J Vis Exp. 2026 Jul 07.
      Mitochondrial ATP-dependent proteases are essential for maintaining protein homeostasis through degradation of damaged or misfolded proteins. Among these, the ClpXP protease complex locates in mitochondrial matrix and contributes to mitochondrial quality control under physiological and stress conditions. This work demonstrates a quantitative fluorescence microscopy workflow to assess mitochondrial targeting of the fluorescent peptidyl inhibitor FAM-FAPAL-CMK and evaluate mitochondrial morphological changes associated with ClpXP inhibition in mammalian cells. HeLa cells were treated with FAM-FAPAL-CMK and analyzed using confocal microscopy combined with immunofluorescence staining of mitochondrial markers and quantitative image analysis. Colocalization analysis using Costes thresholding and Manders' overlap coefficients demonstrated mitochondrial enrichments of the inhibitor signal. As a consequence, inhibition of ClpP altered mitochondrial morphology. Immunoblot analysis showed no significant change in ClpP protein abundance upon inhibitor treatment. Taken together, this work describes a reproducible imaging-based workflow that will enable interrogation of mitochondrial ClpXP functions in intact cells in response to perturbations of homeostasis, such as oxidative stress.
    DOI:  https://doi.org/10.3791/72089
  29. Eur J Hum Genet. 2026 Jul 29.
      Rare genetic diseases (RDs), though individually uncommon, collectively impose a substantial global burden with significant social, emotional and economic implications. Understanding the lived experiences of RD patients, caregivers and service providers is essential to fully address the challenges they face. This study presents a narrative synthesis of original qualitative research on RDs published between 2004 and 2024, identifying 317 studies across multiple databases. Reflexive thematic analysis was used to synthesise and interpret the findings, allowing for an integrative understanding of both commonalities and disparities in experiences and research focus globally. While studies from Europe (45%) and North America (32%) dominated the field, markedly fewer included participants from Africa (3%), Asia (11%) and South America (2%), particularly from low- to middle-income countries. Across studies, recurring themes included navigating emotional resilience; the redefinition of identity in the face of RD; the social experience of illness; healthcare experiences, including access to and quality of healthcare services; the financial and logistical burden of care; the experience of research and new technologies; and the influence of society, culture and power structures. The pronounced underrepresentation of LMIC settings, persisting despite targeted search efforts, is itself a substantive finding, raising critical questions about where rare disease knowledge is produced and whose experiences are considered worthy of formal documentation. The synthesis underscores the urgent need for geographically inclusive, methodologically diverse and community-engaged approaches to qualitative RD research.
    DOI:  https://doi.org/10.1038/s41431-026-02201-y
  30. Neurol Int. 2026 Jul 21. pii: 139. [Epub ahead of print]18(7):
      Neurodegenerative diseases represent a major and growing global health burden. Although these disorders are often clinically defined by symptoms and affected brain regions, many are mechanistically linked to abnormal protein accumulation, misfolding, impaired proteostasis, RNA dysregulation, mitochondrial dysfunction, and neuroinflammation. In this Perspective article, I discuss major neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, dementia with Lewy bodies, multiple system atrophy, amyotrophic lateral sclerosis, frontotemporal dementia, Huntington's disease, prion diseases, spinocerebellar ataxias, and spinal muscular atrophy, through the lens of disease-associated proteins and experimental modeling. I argue that a protein-centered framework provides a useful approach for understanding disease mechanisms and selecting transgenic mouse models, while recognizing that aging, cellular context, neuroinflammation, mitochondrial dysfunction, vascular dysfunction, and other disease modifiers also shape neurodegeneration. Transgenic and genetically engineered mouse models have been essential for dissecting the pathogenic roles of amyloid-β, tau, α-synuclein, TDP-43, SOD1, FUS, C9ORF72-associated dipeptide repeat proteins, mutant huntingtin, prion protein, ataxins, and SMN deficiency. However, these models have important limitations, including artificial overexpression, familial mutation bias, species differences, and incomplete representation of aging-related sporadic diseases. Rather than seeking a single "best" model, a more productive strategy is to adopt model portfolios tailored to specific biological questions and to integrate mouse studies with human cellular models, postmortem tissue, omics approaches, and biomarker-based validation. Such an approach may improve mechanistic insight, strengthen translational relevance, and enhance the predictive value of preclinical neurodegenerative disease research.
    Keywords:  Alzheimer’s disease; Parkinson’s disease; TDP-43; amyotrophic lateral sclerosis; neurodegenerative diseases; neuroinflammation; proteinopathy; tau; transgenic mouse models; α-synuclein
    DOI:  https://doi.org/10.3390/neurolint18070139
  31. CNS Neurosci Ther. 2026 Jul;32(7): e71060
       BACKGROUND: Stroke remains a major global cause of death and disability, with many patients either missing the therapeutic window or responding poorly to current first-line treatments. Consequently, secondary neurological injury, driven predominantly by neuroinflammation, has emerged as a critical therapeutic target. Microglia rapidly sense post-stroke microenvironmental changes and adopt distinct inflammatory phenotypes that shape pathophysiological outcomes.
    RESULTS: Accumulating evidence, including high-resolution spatial profiling and single-cell omics, positions mitochondrial dysfunction at the core of these responses. This review synthesizes recent findings on microglial mitochondrial dysfunction in stroke, introducing the concept of a microglial mitochondrial "storm center". In this model, reactive oxygen species (ROS) trigger an inflammatory cascade, while impairments in mitochondrial quality control (MQC) exacerbate pathogenic signaling. Metabolic reprogramming further sustains inflammatory polarization, influencing interactions with neurons, astrocytes, and endothelial cells.
    CONCLUSIONS: This "storm center" provides a conceptual framework for developing strategies to mitigate secondary brain injury. Finally, this review highlights key molecular mechanisms, potential therapeutic targets, and translational opportunities, providing a stronger foundation for future stroke research and therapeutic innovation.
    Keywords:  fusion/fission dynamics; metabolic reprogramming; microglia; mitochondrial dysfunction; mitochondrial transplantation; mitophagy; neuroinflammation; stroke
    DOI:  https://doi.org/10.1002/cns.71060
  32. Redox Biol. 2026 Jul 24. pii: S2213-2317(26)00318-6. [Epub ahead of print]96 104319
      Aging is characterized by a progressive decline in cellular integrity and function, making it a major risk factor for numerous disease pathologies. Mitochondrial dysfunction and oxidative stress have long been recognized as contributors to the aging phenotype. The loss of mitochondrial function and the overproduction of reactive oxygen species (ROS) are linked to many hallmarks of aging and are associated with a wide range of diseases; however, their role in the aging process is nuanced. Mitochondria produce ROS as harmful respiratory byproducts, but ROS can also act as a signaling molecule with emerging functions linked to variables such as location, timing, and quantity. Similarly, mitochondrial dysfunction is often broadly categorized, overlooking its multifaceted nature and diverse contributions to aging. Due to this complexity, our understanding of how mitochondrial ROS production shapes disease processes and aging hallmarks remains limited. This review aims to clarify the complex and nuanced role of mitochondrial ROS in aging by focusing on ROS production within mitochondria, especially complexes I, II and III, and exploring how these localized ROS influence various hallmarks of aging to contribute to the aging phenotype.
    Keywords:  Aging; And complex III; Complex I; Complex II; Hallmarks of aging; Mitochondria; Mitochondrial ROS; Oxidative stress
    DOI:  https://doi.org/10.1016/j.redox.2026.104319
  33. bioRxiv. 2026 Jul 17. pii: 2026.07.16.738964. [Epub ahead of print]
      Large-scale mitochondrial DNA (mtDNA) deletions cripple oxidative phosphorylation once they exceed a critical heteroplasmy threshold, causing incurable mitochondrial pathologies. Using a genome-wide CRISPR/Cas9 screen in an engineered human cell line carrying a large-scale mtDNA deletion at high heteroplasmy, we identified mitochondrial transcription termination factor 1 (MTERF1) as a suppressor of the heteroplasmy burden. Loss of MTERF1 restored mitochondrial function and increased cellular proliferation in cells with a mtDNA deletion burden exceeding the pathogenic threshold, without altering heteroplasmy or mtDNA copy number. MTERF1 binds wild-type and deletion-bearing mitochondrial genomes indiscriminately at a site downstream of the ribosomal RNA genes and curbs transcription. Relieving this constraint broadly increased OXPHOS transcripts, thereby eliciting more respiratory output from the residual wild-type genomes. Notably, the buffering effect of MTERF1 loss extended beyond mtDNA deletions. In a counter-screen, MTERF1 loss could also restore respiratory growth in cells depleted of nuclear-encoded mitochondrial genes such as OPA1 and COX5A . Together, these findings indicate that by relieving a transcriptional constraint, MTERF1 loss compensates for reduced genome dosage, defining a strategy to enhance residual mitochondrial function in mtDNA deletion disorders and related conditions.
    DOI:  https://doi.org/10.64898/2026.07.16.738964
  34. Acta Neurol Belg. 2026 Jul 27.
      POLG-related disease is a multisystem mitochondrial disorder that may mimic primary neurodegenerative syndromes. We report a 70-year-old man with progressive cognitive decline, rigid-akinetic parkinsonism, postural instability, vertical supranuclear gaze palsy, and prominent executive and semantic fluency deficits, forming a PSP/FTD-like phenotype. Brain MRI showed frontotemporal-predominant cortical atrophy and a hummingbird sign, while FDG-PET demonstrated frontal and bilateral parietotemporal hypometabolism with preserved occipital metabolism. Alzheimer disease CSF biomarkers were normal and RT-QuIC was negative. Pancytopenia with macrocytosis, liver cirrhosis, and myelodysplastic syndrome indicated multisystem involvement. Genetic testing identified biallelic POLG variants, one pathogenic and one likely pathogenic, confirming POLG-related disease. Levodopa produced partial improvement. This case expands the recognised late-onset POLG spectrum and supports POLG testing in atypical parkinsonism accompanied by cognitive, hepatic, or haematological abnormalities. Early diagnosis may prevent valproate-associated severe hepatotoxicity.
    Keywords:  Atypical parkinsonism; Frontotemporal dementia; Mitochondrial disease; POLG; Progressive supranuclear palsy
    DOI:  https://doi.org/10.1007/s13760-026-03145-2
  35. Expert Opin Biol Ther. 2026 Jul 25.
       INTRODUCTION: Inborn errors of immunity (IEI) are rare genetic defects that disrupt immune function, often resulting in life-threatening infections, malignancies, and immune dysregulation. Allogeneic hematopoietic stem cell transplantation (HSCT), a curative option for some diagnoses, is limited by donor availability and risks of graft-versus-host disease. This review explores the 30-year evolution of autologous gene therapy as a vital alternative to allogeneic hematopoietic stem cell transplantation for IEIs.
    AREAS COVERED: Literature search using PubMed for gene therapy for IEI in the last 20 years. We trace the transition from early gamma-retroviral gene addition - which successfully restored immunity in severe combined immunodeficiency (SCID) but carried high risks of insertional mutagenesis and leukemogenesis - to the adoption of safer self-inactivating lentiviral vectors. The field is rapidly advancing beyond viral gene addition toward highly precise gene editing technologies, including CRISPR/Cas9, and base/prime editing, which offer targeted correction with minimized genotoxicity.
    EXPERT OPINION: Recent milestones in diseases like Wiskott-Aldrich syndrome (WAS) and chronic granulomatous disease (CGD) highlight enormous scientific success, yet significant barriers to accessibility, manufacturing, and affordability remain. Overcoming this requires innovative regulatory frameworks and collaborative funding models. Streamlining development and ensuring equitable access are essential next steps to establishing gene therapy as a safe alternative.
    Keywords:  Gene therapy; gene addition; gene editing; inborn errors of immunity
    DOI:  https://doi.org/10.1080/14712598.2026.2710870
  36. Clin Res Hepatol Gastroenterol. 2026 Jul 28. pii: S2210-7401(26)00138-5. [Epub ahead of print] 102892
      Rare genetic liver diseases collectively affect millions of individuals worldwide and encompass a heterogeneous group of monogenic disorders including Wilson disease, alpha-1 antitrypsin deficiency, glycogen storage diseases, urea cycle disorders, progressive familial intrahepatic cholestasis, and acute hepatic porphyrias. While conventional management relies on dietary modification, pharmacotherapy, and ultimately liver transplantation, the advent of clustered regularly interspaced short palindromic repeats (CRISPR)-based gene editing has opened transformative therapeutic avenues. This review provides a comprehensive and critical appraisal of the current landscape of CRISPR-based therapies for genetic liver diseases, from preclinical proof-of-concept studies to landmark clinical trials. We examine the evolution from conventional Cas9 nuclease-mediated editing to precision tools including base editors and prime editors, which enable single-nucleotide corrections without inducing double-strand DNA breaks. The role of lipid nanoparticle delivery systems in achieving efficient hepatocyte-targeted delivery is discussed, alongside emerging challenges in pediatric dosing and immunogenicity. We highlight the paradigm shift toward personalized, patient-specific CRISPR therapies, exemplified by the first-in-human bespoke gene editing treatment delivered in 2025. Competing nucleic acid technologies, including RNA interference and antisense oligonucleotides, are compared in terms of durability, safety, and cost-effectiveness. Finally, we critically evaluate the evolving regulatory landscape and propose a priority framework for selecting genetic liver diseases most amenable to CRISPR-based correction. This review underscores that CRISPR gene editing is transitioning from experimental promise to clinical reality for genetic liver diseases, with personalized approaches poised to redefine the treatment paradigm.
    Keywords:  Base editing; CRISPR; Gene editing; Gene therapy; Genetic liver disease; Lipid nanoparticles; Personalized medicine
    DOI:  https://doi.org/10.1016/j.clinre.2026.102892
  37. Forensic Sci Int Genet. 2026 Jul 23. pii: S1872-4973(26)00174-2. [Epub ahead of print]86 103593
      This EDNAP (European DNA Profiling Group) collaborative study evaluated the detection and reporting of mitochondrial DNA (mtDNA) point heteroplasmy (PHP) and length heteroplasmy (LHP) across forensic laboratories using Sanger, Ion Torrent, and Illumina sequencing platforms. Standardized DNA extracts were centrally prepared and distributed to participating laboratories to assess inter-laboratory concordance and platform-specific (platform = instrument + software) effects. Raw sequence data showed high overall consistency across platforms, and observed mitotype discrepancies were due to transcription errors. PHP detection was generally concordant across laboratories and technologies. MPS data provided relatively stable mixture ratios across platforms. Low-level PHPs were often not reported in this study when they fell below laboratory-specific minor allele frequency thresholds, although raw data review confirmed their presence. In contrast, LHP interpretation showed substantially greater variation. Sanger-derived LHP patterns could be harmonized through review under current ISFG guidelines, whereas MPS-based LHP results differed both between and within sequencing technologies. Standardization of the alignment workflow improved concordance to some extent, but important discrepancies remained, particularly in Ion Torrent HVS-I (Hypervariable Segment I) poly(C)-tract data. These differences were attributable to sequencing technology, analysis software, and human interpretation.
    Keywords:  Forensic Genetics; Homopolymeric poly(C)-tracts; Interpretation; Mitochondrial DNA; Next Generation Sequencing
    DOI:  https://doi.org/10.1016/j.fsigen.2026.103593
  38. Rev Inst Med Trop Sao Paulo. 2026 ;pii: S0036-46652026000100226. [Epub ahead of print]68 e48
      Circulating cell-free mitochondrial DNA (ccf-mtDNA) has emerged as a potential biomarker of tissue injury and systemic inflammation, acting as a mitochondrial damage-associated molecular pattern (DAMP) capable of activating innate immune pathways. However, most studies have focused on acute inflammatory conditions, and the behavior of ccf-mtDNA across distinct immunological and metabolic disease states remains poorly characterized, particularly in pediatric populations. This study investigated whether circulating ccf-mtDNA levels vary according to the clinical and immunometabolic context rather than simply reflecting the presence of inflammation. Serum ccf-mtDNA copy number was quantified by quantitative polymerase chain reaction (qPCR) targeting the mitochondrial ND2 gene in 181 clinical samples obtained from five groups: adults with chronic-active and/or treatment-refractory pulmonary tuberculosis (n = 47); asymptomatic children with latent tuberculosis infection confirmed by interferon-gamma release assay (IGRA) without clinical, radiological or microbiological evidence of active disease (n = 11); children with severe chronic underlying diseases in clinically stable condition (n = 41); children undergoing cardiac surgery with cardiopulmonary bypass (CPB), with perioperative serial sampling (n = 52); and healthy young adult blood donors as controls (n = 30). Non-parametric statistical tests were applied due to non normal data distribution. Median ccf-mtDNA levels in controls were 649.3 copies/μL. Adults with chronic-active pulmonary and/or treatment-refractory tuberculosis and children undergoing cardiac surgery with CPB did not exhibit significantly elevated ccf-mtDNA levels compared with controls. In contrast, significantly higher levels were observed in IGRA-positive children with latent tuberculosis infection (median: 1,648.5 copies/μL; p = 0.0004) and in children with severe chronic underlying diseases despite the absence of overt infection or inflammation (median: 2,663.9 copies/μL; p = 0.0001). These findings suggest that circulating ccf-mtDNA does not behave as a simple linear marker of inflammatory intensity. Instead, its levels appear to reflect the interaction between mitochondrial injury, immune activation, metabolic competence, and clearance mechanisms. We propose a phase-dependent model in which mitochondrial DAMP signaling is amplified during sustained but metabolically competent immune engagement, and is attenuated during advanced immunometabolic exhaustion. These findings suggest that ccf-mtDNA levels are shaped by the host's underlying immunometabolic context, rather than simply mirroring the intensity of systemic inflammation.
    DOI:  https://doi.org/10.1590/S1678-9946202668048
  39. Biomolecules. 2026 Jul 04. pii: 987. [Epub ahead of print]16(7):
      Mitochondria-targeting metal complexes (MTMCs) are a mechanistically distinct class of metallopharmaceuticals. Unlike first-generation platinum drugs that form nuclear DNA adducts, MTMCs exploit organelle-specific vulnerabilities such as hyperpolarised mitochondrial membrane potential (ΔΨm), elevated reactive oxygen species (ROS), limited mitochondrial DNA (mtDNA) repair capacity, and redox-dependent enzymes such as thioredoxin reductase (TrxR). We systematically searched PubMed, Web of Science, Scopus, and Google Scholar databases for studies published between 2016 and 2026, applying predefined inclusion criteria that included subcellular localization evidence and functional bioenergetic endpoints. The search identified 147 studies covering Pt(II/IV), Ru(II/III), Au(I/III), Ir(III), Os(II), Re(I), and V(IV/V) complexes and metal-organic framework nanoplatforms. Mechanistic evidence converges on four intramitochondrial target categories: inhibition of ETC (Electron Transport Chain) Complexes I/III with consequent ATP depletion; ROS overproduction, coupled with glutathione and TrxR depletion; outer mitochondrial membrane permeabilization and intrinsic apoptotic cascade activation; and mtDNA damage within a compartment limited to base excision repair. Multi-modal cell death-the co-occurrence of apoptosis, ferroptosis, necroptosis, and autophagic cell death-was a recurrent finding across the reviewed studies. This review thoroughly surveys the latest trends in MTMC drug design (metals, ligand structures, and mechanisms of action) and summarises analytical techniques for speciation, pharmacokinetics, safe monitoring, and resistance, while critically analysing translational barriers and clinical failures. To address the field's inconsistent terminology, we introduce an explicit localization evidence hierarchy that distinguishes mitochondria-targeting complexes (through quantitative ICP-MS fractionation or co-localization with defined Pearson/Manders coefficients) from simply mitochondria-localising or mitochondria-perturbing agents, and we apply it throughout. We also point out that the idea of selectivity being purely driven by membrane voltage (ΔΨm) and thermodynamics is constrained by membrane and protein binding, as well as the transmembrane pH gradient, kinetic limitations, and demonstrated heterogeneity of cancer-cell membrane potential, and, as such, the functional mitochondrial effects must not be equated with mitochondrial accumulation. Since elemental quantification cannot distinguish intact complex from protein adducts and decomposition products, speciation-aware pharmacokinetics emerges as a prerequisite for a credible exposure-response interpretation. The translational progress will depend less on new chemotypes than on this analytical and pharmacokinetic rigour, together with organelle-level safety monitoring and biomarker-guided patient selection.
    Keywords:  ICP-MS; apoptosis; bioinorganic chemistry; clinical safety monitoring; electron transport chain; metal complexes; metallodrugs; mitochondria; reactive oxygen species; speciation; theranostics; translational failure; ΔΨm
    DOI:  https://doi.org/10.3390/biom16070987
  40. Pharmacol Res. 2026 Jul 29. pii: S1043-6618(26)00275-6. [Epub ahead of print] 108360
      Drug repurposing offers a faster and less costly route to therapeutic development, yet its translational success remains constrained by a critical scientific and evidentiary gap: the absence of human-relevant intermediate validation systems capable of converting computationally generated candidates into biologically grounded, clinically actionable evidence. In this opinion paper, we propose that human organoid platforms-particularly when integrated with artificial intelligence (AI)-driven candidate prioritisation upstream and multidimensional data analytics downstream-can function as context-specific, fit-for-purpose functional decision layers within repurposing pipelines-decision-grade within a defined context of use rather than as a generalisable property of the platform. We outline a hybrid framework coupling in silico discovery, organoid-based functional validation, and AI-enabled response interpretation, and we propose the disease categories in which this approach is most immediately applicable. We further discuss current operational challenges alongside their enabling solutions, and contextualise the framework within the evolving regulatory landscapes of the FDA and EMA as both agencies advance the integration of New Approach Methodologies (NAMs).
    Keywords:  artificial intelligence; drug repurposing; in silico; new approach methodologies; organoids; rare diseases; translational pharmacology
    DOI:  https://doi.org/10.1016/j.phrs.2026.108360
  41. DNA Cell Biol. 2026 Jul 30. 10445498261473080
      Replacement therapy is an advanced therapeutic approach for diseases caused by molecular deficits. It aims to restore normal physiology by replacing deficient molecules such as enzymes, proteins, genes, or other molecules. Here, we discuss different modalities, including protein replacement, gene therapy, messenger RNA (mRNA) replacement, noncoding RNA (ncRNA) therapies, cell replacement, and gene editing, aimed at addressing and treating the fundamental genetic defects underlying a range of diseases. These therapies could have potentially curative and disease-modifying effects when used to directly replace deficient or dysfunctional components, addressing the inherent limitations of conventional therapies, such as off-target effects and control of disease-related symptoms. Some replacement therapies, such as protein therapy, gene therapy, and cell therapy, are already approved for clinical use, while emerging approaches-including mRNA therapy, ncRNA therapy, and gene editing-remain primarily in the preclinical or clinical trial stages. To achieve broad clinical translation of these emerging approaches, key challenges, including delivery, safety, specificity, and ethical concerns, must be addressed. This review provides an overview of the existing modalities of replacement therapies, their mechanisms of action, and future directions for improving clinical translation, efficacy, and accessibility.
    Keywords:  cell therapy; gene editing; gene therapy; mRNA; ncRNA; replacement therapy
    DOI:  https://doi.org/10.1177/10445498261473080