bims-mitmed Biomed News
on Mitochondrial medicine
Issue of 2026–03–15
twenty papers selected by
Dario Brunetti, Fondazione IRCCS Istituto Neurologico



  1. Cell. 2026 Mar 11. pii: S0092-8674(26)00173-X. [Epub ahead of print]
      Mitochondrial disease encompasses inherited disorders affecting mitochondrial function. A severe and untreatable form of mitochondrial disease is Leigh syndrome (LS), causing psychomotor regression and metabolic crises. To accelerate drug discovery for LS, we screen a library of 5,632 repurposable compounds in neural cells from LS-patient-derived induced pluripotent stem cells (iPSCs). We identify phosphodiesterase type 5 (PDE5) inhibitors as leads and prioritize sildenafil for its clinical safety. Sildenafil corrects mitochondrial membrane potential defects, restores neurodevelopmental pathways, and normalizes calcium responses in LS brain organoids. In small and large mammalian models of LS, sildenafil extends lifespan and ameliorates disease phenotypes. Off-label treatment on an individual basis with sildenafil in six LS patients improves their motor function and resistance to metabolic crises. Collectively, the findings highlight the potential of iPSC-driven drug discovery and position sildenafil as a promising drug candidate for mitochondrial disease.
    Keywords:  Leigh syndrome; PDE5 inhibitors; PRKG1; brain organoids; drug repurposing; drug screening; high-content analysis; iPSCs; mitochondrial diseases; sildenafil
    DOI:  https://doi.org/10.1016/j.cell.2026.02.008
  2. Nat Commun. 2026 Mar 13.
      Mitochondrial diseases progressively lead to multisystemic failure with treatment options remaining extremely limited. Here, to investigate strategies that alleviate mitochondrial dysfunction, we first generate a ubiquitous and tamoxifen-inducible knockout mouse model of mitochondrial transcription factor A (TFAM), a nuclear-encoded protein involved in mitochondrial DNA (mtDNA) maintenance - Tfamfl/flUbcCre-ERT2 (iTfamKO) mice. Systemic TFAM deficiency triggers mitochondrial decline in a myriad of tissues in adult mice. Consequently, iTfamKO mice manifest multiorgan dysfunction including lipodystrophy, sarcopenia, metabolic alterations, kidney failure, neurodegeneration, and locomotor dysregulation, which result in the premature death of these mice. Interestingly, iTfamKO mice display intestinal barrier disruption and gut dysbiosis, with diminished levels of microbiota-derived short-chain fatty acids (SCFAs), such as butyrate. Mice with a deficient proof-reading version of the mtDNA polymerase gamma (mtDNA-mutator mice) phenocopy the dysfunction of the intestinal barrier and bacterial dysbiosis with reduced levels of butyrate, suggesting that different mouse models of mitochondrial dysfunction share insufficient generation of butyrate. Transfer of microbiota from healthy control mice or administration of tributyrin, a butyrate precursor, delay multiple signs of multimorbidity, extending lifespan in iTfamKO mice. Mechanistically, butyrate supplementation recovers epigenetic histone acylation marks that are lost in the intestine of Tfam deficient mice. Overall, our findings highlight the relevance of preserving host-microbiota symbiosis in disorders related to mitochondrial dysfunction.
    DOI:  https://doi.org/10.1038/s41467-026-70547-4
  3. Hum Reprod. 2026 Mar 08. pii: deag020. [Epub ahead of print]
      Mitochondrial replacement therapies (MRTs) have been proposed as a means of avoiding the transmission of pathogenic mitochondrial DNA (mtDNA) mutations from mother to child. While clinical cases using this groundbreaking strategy have now been reported for the two principal MRT methods-pronuclear transfer and maternal spindle transfer-recent data continues to raise questions about the reliability of these approaches for disease prevention.
    Keywords:  female infertility; maternal spindle transfer; mitochondrial diseases; mitochondrial replacement therapies; mitochondrial reversal; oocyte quality; pronuclear transfer
    DOI:  https://doi.org/10.1093/humrep/deag020
  4. Hum Reprod. 2026 Mar 13. pii: deag027. [Epub ahead of print]
      Maternal spindle transfer (MST) and pronuclear transfer (PNT) raise a number of important ethical and regulatory issues. These IVF procedures that transfer nuclear DNA to enucleated oocytes or zygotes aim to prevent transmitting mitochondrial disease by female carriers of mitochondrial DNA (mtDNA) mutations and enable them to have healthy genetically related children. MST/PNT might also prove effective in treating oocyte-related infertility, but are not permitted in the UK and Australia, unlike MST/PNT for mtDNA disorders. The paper discusses the regulation of MST/PNT for both applications in relation to their risks and efficacy, highlighting the scarcity of clinical data. Based on risk reduction, it has even been proposed to treat oocyte-related infertility first before moving to mtDNA disorders. We argue that a prohibition of MST/PNT for infertility is not justified, neither should it initially be applied only for infertility because of the little evidence yet available regarding its efficacy and potential risks. We propose a staged approach to identify MST/PNT-treatable causes of oocyte-related infertility first, followed by a preclinical study and clinical trial and, if positive, wider application. Importantly, we call for transparency in publishing regular trial results, deeper ethical reflection, and more consistent policies that consider comparable uncertainties in mtDNA disorders and oocyte-related infertility.
    Keywords:  assisted reproduction; ethics; maternal spindle transfer; mitochondria; mitochondrial DNA disorders; mitochondrial donation; nuclear transfer; oocyte-related infertility; pronuclear transfer; translational research
    DOI:  https://doi.org/10.1093/humrep/deag027
  5. Neurol Genet. 2026 Apr;12(2): e200365
       Background and Objectives: POLG-related disorders exhibit marked phenotypic heterogeneity and frequent clinical overlap, often leading to delayed diagnosis. A precise delineation of their clinical spectrum, natural history, and the identification of reliable biomarkers is essential to improve diagnostic accuracy and guide therapeutic development.
    Methods: We analyzed a cohort of 34 patients with confirmed pathogenic POLG variants, assessing clinical phenotypes, molecular findings, and biomarkers (plasma growth differentiation factor-15 [GDF15] in 16, plasma neurofilament light chain [NF-L] in 14, and mitochondrial DNA [mtDNA] copy number in muscle in 16).
    Results: Thirty four patients (0.6-71 years) from 33 families were included. Juvenile/adult onset (12-40 years) was the most common presentation (62%). The predominant phenotypic categories were ataxia-neuropathy spectrum ([ANS], 44%), autosomal recessive PEO-plus (arPEO-plus, 26%), and autosomal dominant PEO-plus ([adPEO-plus], 15%), with frequent phenotypic overlap. Recessive inheritance accounted for 74% of cases, with the most common variants being p.([Thr251Ile; Pro587Leu]) paired on 1 allele, p.(Ala467Thr), and p.(Trp748Ser). Dominant variants were associated with milder, primarily myopathic phenotypes. The most common dominant variant was p.(Tyr955Cys). No clear genotype-phenotype correlations were identified among recessive variants. Compared with previously reported cohorts, our patients exhibited a lower prevalence of seizures, hepatopathy, and stroke-like episodes. GDF15 was elevated in 87.5% of patients, with a mean level of 3,315 pg/mL (±1,559.79), showing no significant differences between myopathic and ANS phenotypes, supporting its role as a general biomarker of mitochondrial dysfunction. NF-L was elevated in 78.6% of tested individuals but did not correlate with phenotype or clinical severity (as per Newcastle Mitochondrial Disease Adult Scale score).On average, muscle mtDNA copy number in patients was 76% of that observed in controls, with no differences by phenotype or inheritance pattern. All but 1 patient exhibited multiple mtDNA deletions, likely representing the primary mechanism of oxidative phosphorylation dysfunction rather than mtDNA depletion.
    Discussion: POLG-related disorders demonstrate extensive clinical variability with no consistent genotype-phenotype correlation. GDF15 and NF-L may serve as useful, though nonspecific, biomarkers of mitochondrial and neuroaxonal dysfunction, respectively. Prospective studies incorporating advanced molecular profiling are essential to establish reliable outcome measures and inform future therapeutic strategies.
    DOI:  https://doi.org/10.1212/NXG.0000000000200365
  6. Mol Genet Metab. 2026 Mar 09. pii: S1096-7192(26)00150-2. [Epub ahead of print]148(2): 109867
      Isolated mitochondrial complex III deficiency can result from pathogenic variants in several nuclear or mitochondrial genes, encoding structural subunits or assembly factors of the enzyme. It is a rare cause of mitochondrial phenotypes with clinically heterogeneous presentations. Pathogenic variants in the Tetratricopeptide Repeat Domain 19 (TTC19) gene have been identified as a cause of mitochondrial complex III deficiency, nuclear type 2 (MIM #615157). We report 10 patients from five unrelated Arab families, all presenting with variable severity of a progressive neurodegenerative disorder characterized by loss of ambulation, speech impairment, and cognitive regression. Long-term clinical follow-up, supported by serial neuroradiological imaging, demonstrated progressive disease evolution, further highlighting the degenerative nature of the condition. In this cohort, exome sequencing (ES) identified three distinct pathogenic variants in the TTC19 gene across the five unrelated families, highlighting both genetic heterogeneity and regional clustering. In a Saudi family, A novel in-frame TTC19 variant NM_017775.4:c.680_709del; p.(Glu227_Leu236del) was identified, resulting in the loss of 10 amino acids in the protein. The second variant, NM_017775.4:c.779_780del; p.(Tyr260*), is a frameshift deletion leading to truncation of the TTC19 protein. This recurrent variant was identified in three independent Syrian families (Families 2, 3, and 4). The third variant, NM_017775.4:c.153_156del; p.(Arg52Alafs*48), also a frameshift variant, was detected in a fifth family of Kuwaiti origin. These loss of function TTC19 variants are proposed to underlie the observed phenotypes, as supported by mitochondrial functional studies, and contribute to the expanding spectrum of TTC19-related disorders, with specific variants recurring in particular regional or ethnic populations.
    Keywords:  Ataxia; Cognitive regression; Mitochondrial complex III deficiency; Mitochondrial respiratory chain complex III; Nuclear type 2 (MC3DN2); Progressive neurodegenerative disorder; Tetratricopeptide 19 (TTC19) gene
    DOI:  https://doi.org/10.1016/j.ymgme.2026.109867
  7. Cell Rep. 2026 Mar 06. pii: S2211-1247(26)00104-X. [Epub ahead of print]45(3): 117026
      Endogenous (self) double-stranded RNAs (dsRNAs) in human cells can activate innate immune responses. ADAR1, an A-to-I editing enzyme of dsRNAs, suppresses aberrant immune activation by self-dsRNAs. However, how ADAR1 influences the cellular dsRNA landscape remains unclear. We show that human ADAR1 downregulates self-dsRNA abundance through editing-dependent and editing-independent mechanisms. We further conducted quantitative dsRNA sequencing on wild-type and ADAR1-deficient cells. dsRNAs are enriched in protein-coding mRNAs-especially those with repetitive elements and elongated 3' UTRs-and mitochondrial RNAs. ADAR1-regulated dsRNA transcripts consist of nuclear-encoded mRNAs and, unexpectedly, mitochondria-encoded RNAs rarely edited by ADAR1. Accordingly, dsRNAs accumulate to high levels within the mitochondria of ADAR1-deficient cells. Mass spectrometry and biochemical assays can detect ADAR1p150 in mitochondrial fractions. Notably, ADAR1 loss sensitizes cells to inflammation under mitochondrial stress (e.g., herniation and X-ray irradiation). Hence, we show that dsRNAs regulated by ADAR1 go beyond A-to-I edited transcripts and that ADAR1 can control mitochondrial dsRNAs.
    Keywords:  A-to-I editing; ADAR1; AGS; Aicardi-Goutieres syndrome; CP: immunology; CP: molecular biology; IFN; PKR; double-stranded RNA; dsRNA; dsRNA-seq; innate immunity; mitochondria; mitochondrial stress; protein kinase R; type 1 interferon
    DOI:  https://doi.org/10.1016/j.celrep.2026.117026
  8. PLoS Genet. 2026 Mar;22(3): e1012076
      COG5, a subunit of the conserved oligomeric Golgi (COG) complex, plays a critical role in retrograde trafficking within the Golgi apparatus. Dysfunction of COG5 is associated with various human disorders, yet the underlying pathogenic mechanisms remain poorly understood. To investigate the mechanisms, we conducted proteomic analyses using COG5-deficient and rescue cell models, which revealed a potential link between COG5 dysfunction and mitochondrial oxidative phosphorylation (OXPHOS) deficiency. Using COG5-deficient cell models and patient-derived cells harboring COG5 variants, we biochemically validated the involvement of COG5 in mitochondrial OXPHOS, particularly in the regulation of complex I content. These models also exhibited elevated cellular copper levels. Notably, the significant reduction in OXPHOS complexes could be rescued by either restoring COG5 expression or administering a copper chelator. We further demonstrated that excessive cellular copper disrupts the function of mitochondrial iron-sulfur clusters, potentially leading to complex I assembly defects. Additionally, we identified a patient with biallelic COG5 variants presenting with a distinct subtype of mitochondrial disease (Leigh syndrome), a phenotype not previously associated with COG5-related disorders. These findings provide novel mechanistic insights into the role of COG5, extending beyond its established function in Golgi-mediated glycosylation modifications. Our results underscore the importance of COG5 in mitochondrial function through a copper-dependent pathway, offering new perspectives on its contribution to cellular homeostasis and disease pathogenesis.
    DOI:  https://doi.org/10.1371/journal.pgen.1012076
  9. Int J Mol Sci. 2026 Feb 24. pii: 2117. [Epub ahead of print]27(5):
      Mitochondria-endoplasmic reticulum contacts (MERCs) are physical structures formed between mitochondria and the endoplasmic reticulum (ER) through various tethering proteins, playing crucial roles in multiple physiological processes, including Ca2+ and lipid exchange between the ER and mitochondria, regulation of mitochondrial morphology and dynamics (fusion and fission), as well as the induction of autophagy and apoptosis. Mitofusin 2 (MFN2), a key mitochondrial fusion protein, has been identified as an essential structural component of MERCs. Our research demonstrates that 16:8 circadian intermittent fasting (CIF) leads to enhanced mitochondrial fusion. The upregulation of MFN2 reinforces MERC stability, thereby facilitating efficient Ca2+ transfer between the ER and mitochondria. This process sustains the activity of mitochondrial oxidative phosphorylation (OXPHOS) enzymes, elevates mitochondrial oxygen utilization efficiency, and ultimately augments ATP production. Consequently, these adaptations enhance cardiomyocyte tolerance to hypoxic conditions. This study elucidates a novel mechanism by which MERCs regulate cellular hypoxia resistance and proposes a potential therapeutic strategy for improving acute hypoxia tolerance through the modulation of Ca2+ transport at MERCs.
    Keywords:  MERC; calcium transport; cardiomyocyte; circadian intermittent fasting; hypoxia; mitofusin 2
    DOI:  https://doi.org/10.3390/ijms27052117
  10. Pediatr Neurol. 2026 Feb 13. pii: S0887-8994(26)00048-2. [Epub ahead of print]178 138-146
       BACKGROUND: Before diagnostic whole exome sequencing, monogenic/chromosomal developmental and epileptic encephalopathies (DEEs) were frequently misdiagnosed as mitochondrial disorders (MDs) with epilepsy, due to overlapping clinical and biochemical features. Assessing muscle functional assays in patients with a genetic diagnosis and epilepsy offers a unique opportunity to explore mitochondrial dysfunction in monogenic/chromosomal DEEs, in comparison to the mitochondrial dysfunction observed in genetically confirmed MDs.
    METHODS: In this retrospective cohort study, clinical and biochemical data were extracted from patients suspected of MD with epilepsy who underwent muscle/fibroblast biopsy (2005-2015). Patients were classified into four groups based on the final diagnosis. Mitochondrial Disease Criteria scores were assigned. Statistical analyses were conducted using Fisher's exact, analysis of variance, and Kruskal-Wallis tests.
    RESULTS: Of 27 included participants, eleven (40.7%) had DEEs, four (14.8%) had genetically confirmed MDs, eight (29.6%) were suspected MD cases without genetic confirmation, and four (14.8%) had nonmitochondrial metabolic diseases. Mitochondrial dysfunction was common across all groups; 85% of participants met probable/definite Mitochondrial Disease Criteria, over 70% had elevated plasma lactate (>2.5 mmol/L), and 92% exhibited impaired adenosine triphosphate production. Surprisingly, moderate to severe complex dysfunction was observed in all groups except genetically confirmed MDs.
    CONCLUSIONS: Our findings indicate that mitochondrial dysfunction is prevalent in nonmitochondrial DEEs. Patients previously diagnosed with an MD based only on muscle/fibroblast biopsy may benefit from whole exome sequencing to identify genetic variants, for which targeted therapy may be available. Future research should explore whether treatment or prognosis of nonmitochondrial DEEs should be tailored to improve mitochondrial function.
    Keywords:  DEE; Developmental and epileptic encephalopathies; Genetic epilepsy; Mitochondrial disease; Mitochondrial dysfunction; Muscle functional assay; Seizures
    DOI:  https://doi.org/10.1016/j.pediatrneurol.2026.02.004
  11. Trends Endocrinol Metab. 2026 Mar 07. pii: S1043-2760(26)00034-2. [Epub ahead of print]
      Mitochondria play a central role in energy metabolism, redox balance, and cellular homeostasis, and their dysfunction has been implicated in the pathogenesis of complex human diseases. Advances in systems biology and omics technologies have elucidated the mechanisms underlying these conditions, including metabolic dysfunction, mitochondrial impairment, inflammation, and redox imbalance. Preclinical and early clinical studies of combined metabolic activators (CMA), a formulation of bioactive metabolites, have demonstrated improvements in mitochondrial function and systemic metabolic profiles across multiple diseases. In this review, we provide a comprehensive overview of the mechanistic rationale for CMA, summarize evidence from preclinical models and clinical studies investigating CMA and its components, and evaluate its translational potential and challenges as a mitochondrial-targeted therapeutic strategy for complex human diseases.
    Keywords:  NAD(+); combined metabolic activators; glutathione; l-carnitine tartrate; metabolic diseases; mitochondrial dysfunction; serine
    DOI:  https://doi.org/10.1016/j.tem.2026.01.018
  12. Int J Mol Sci. 2026 Feb 26. pii: 2224. [Epub ahead of print]27(5):
      Mitochondrial dysfunction lies at the core of numerous cardiac pathologies, yet restoring mitochondrial health remains a therapeutic frontier. In recent years, extracellular vesicles (EVs) have emerged as nature's delivery nanocarriers, capable of transporting a wide array of biomolecules, including mitochondrial-associated microRNAs (mito-miRs). These miRNAs regulate bioenergetics, redox homeostasis, and apoptotic signaling-making them prime candidates for non-cellular mitochondrial therapy. This review explores the evolving landscape of mitochondrial miRNA encapsulation within EVs, focusing on their potential to restore mitochondrial transcriptional and metabolic programs governing ATP synthesis and redox balance, enhance cellular energy output, and mitigate oxidative stress. We integrate insights from stem cell biology, RNA epigenetics, systems cardiology, and bioengineering, offering a unifying framework for therapeutic applications across ischemic heart disease, heart failure, and chemotherapy-induced cardiomyopathy. An integrative narrative synthesis of recent peer-reviewed literature was performed across major biomedical databases, prioritizing mechanistic studies linking EV-mediated mito-miR delivery to cardiomyocyte mitochondrial function. By harmonizing multi-omic signaling, vesicle engineering, and mitochondrial medicine, this review seeks to guide future research toward targeted, customizable, and scalable bioenergetic interventions-unlocking a next-generation path for cardiovascular regeneration.
    Keywords:  RNA therapeutics; cardiomyocyte bioenergetics; extracellular vesicles (EVs); heart failure; miRNA engineering; mitochondrial microRNAs; non-cellular mitochondrial therapy; regenerative cardiology; systems biology; translational nanomedicine
    DOI:  https://doi.org/10.3390/ijms27052224
  13. Cell. 2026 Mar 09. pii: S0092-8674(26)00161-3. [Epub ahead of print]
      The regulation of nicotinamide adenine dinucleotide (NAD+) is crucial for numerous life processes. However, the mechanisms leading to NAD+ degradation in mitochondria remain insufficiently defined. Through in silico screening of potential NAD-binding proteins, we discovered a mitochondrial reaction in which NAD+ is hydrolyzed to nicotinamide mononucleotide (NMN) and AMP by SELENOO (SelO), using Mn2+ as cofactor. Catalysis depends on SelO's selenocysteine-serine-serine (CSS) C-terminal residues, particularly the selenocysteine 667. In addition to broad metabolic effects, this reaction plays a pronounced role in lipid utilization via SelO directly associating with fatty acid oxidation (FAO) enzymes, and it is conserved in both mammalian cells and bacteria. This reaction is responsive to elevated matrix pH, a signal of enhanced mitochondrial respiration, and protects mitochondria from sustained metabolic overactivation. These findings reveal a conserved mechanism for spatiotemporal NAD+ regulation and highlight its physiological significance in both prokaryotes and eukaryotes.
    Keywords:  NAD; fatty acid oxidation; hydrolysis reaction; mitochondrial homeostasis; nicotinamide adenine dinucleotide; selenocysteine
    DOI:  https://doi.org/10.1016/j.cell.2026.01.033
  14. Aging Dis. 2026 Mar 04.
      Mitochondria are increasingly recognized as central regulators of skin health and aging, providing ATP and coordinating redox signaling, mitophagy, and cell fate decisions. In cutaneous tissues, mitochondrial integrity sustains fibroblast-driven collagen synthesis, keratinocyte proliferation, melanocyte homeostasis, and efficient wound repair. With advancing age and cumulative ultraviolet exposure, mitochondria accumulate hallmark defects. Mitochondrial DNA mutations and deletions, impaired oxidative phosphorylation, excessive reactive oxygen species production, diminished mitophagy and biogenesis, disrupted fission-fusion dynamics, NAD⁺ decline, and sirtuin dysregulation all converge to undermine energy metabolism, amplify inflammatory signaling, and accelerate fibroblast senescence, extracellular matrix degradation, pigmentary changes, and delayed wound healing. Recent research also highlights weakened antioxidant defenses and extracellular vesicle-mediated propagation of mitochondrial stress across the cutaneous microenvironment, underscoring the organelle's central role in skin aging. Against this mechanistic backdrop, mitochondria-targeted interventions are emerging as promising therapeutic strategies. Extracellular vesicles loaded with NAD⁺ precursors, antioxidant enzymes, or mitophagy stimulators show preclinical efficacy in restoring bioenergetics and accelerating wound closure. Mitochondria-directed antioxidants such as melatonin and coenzyme Q10, NAD⁺ boosters and sirtuin activators, red and near-infrared photobiomodulation, and NRF2-based redox reprogramming each enhance mitochondrial homeostasis while improving collagen synthesis, pigmentation balance, and re-epithelialization. Early translational and clinical studies indicate that these approaches protect against UV-induced mitochondrial DNA damage, reduce oxidative stress, and improve cutaneous structure and function. Collectively, these findings position mitochondria as a modifiable hub for cutaneous aging and wound repair, and highlight the potential of integrated metabolic, antioxidant, and vesicle-based approaches to transform dermatologic anti-aging and wound-care interventions.
    DOI:  https://doi.org/10.14336/AD.2025.1585
  15. Free Radic Biol Med. 2026 Mar 10. pii: S0891-5849(26)00216-9. [Epub ahead of print]249 260-272
      Hepatitis E virus (HEV) is a major cause of acute hepatitis globally, yet the mechanisms underlying its replication and pathogenesis remain poorly understood. While mitochondrial dynamics are increasingly recognized as central to antiviral responses, their role in HEV infection has not been defined. Here, we demonstrate that HEV induces profound mitochondrial structural remodeling-characterized by elongated morphology in patient liver biopsies and active mitochondrial fusion in cell culture models, a process essential for viral replication. Mechanistically, this remodeling is driven by a biphasic regulatory program: acute infection preferentially upregulates inner membrane fusion protein OPA1, whereas chronic infection shifts dependence to outer membrane mediator MFN1. Genetic ablation of OPA1 or MFN1 not only reversed mitochondrial elongation but also significantly suppressed HEV replication. Integrated transcriptomic and functional analyses revealed that this virus-induced fusion licenses a pro-viral autophagic response while concurrently dampening interferon-stimulated gene expression. Furthermore, we identified that HEV orchestrates a G0/G1 cell cycle arrest to actively enforce and maintain this pro-fusion mitochondrial state. Clinically, the presence of elongated mitochondrial profiles in patient livers correlated with disease severity, and HEV ORF2 protein levels positively correlated with OPA1/MFN1 expression. Our study establishes mitochondrial fusion as a critical host pathway co-opted by HEV, revealing a previously unrecognized viral strategy that integrates organelle dynamics, autophagy, cell cycle control, and immune evasion to promote replication. These findings position mitochondrial fusion machinery as a promising target for therapeutic intervention against hepatitis E.
    Keywords:  Anti-virus; HEV; Mitochondrial dynamics
    DOI:  https://doi.org/10.1016/j.freeradbiomed.2026.03.025
  16. Front Cell Dev Biol. 2026 ;14 1766635
      The mTOR pathway regulates cell proliferation, growth, survival, and metabolism by integrating nutritional and growth factor signaling. In embryos, its activity is influenced by the availability of nutrients in the culture medium, and it can affect the first cellular differentiation event, driving trophectoderm (TE) formation in mice. We hypothesized that mTOR activity is increased in cells poised to become TE and in differentiated TE cells of early bovine embryos. To test this, we assessed mTOR pathway activity through immunofluorescence detection of phospho-S6 (pS6) using confocal microscopy. In morulae, pS6 activity was primarily observed in the outer cells and in early blastocysts, in the TE, while it disappeared in late blastocysts, suggesting a specific pattern for mTOR localization and activity during early embryonic development in bovine.
    Keywords:  differentiation; inner cell mass; nuclear mTOR; phospho-S6; trophectoderm
    DOI:  https://doi.org/10.3389/fcell.2026.1766635
  17. Ann Child Neurol Soc. 2025 Sep;3(3): 226-231
       Purpose: Adaptor protein complex 4-associated hereditary spastic paraplegia (AP-4-HSP) is a rare childhood-onset neurogenetic disorder. With gene replacement therapies advancing, early-potentially prenatal-diagnosis holds significant clinical promise. We aimed to characterize fetal and perinatal brain MRI features of AP-4-HSP to assess whether early imaging can prompt timely diagnosis, counseling, and interventions.
    Methods: In this retrospective analysis, we reviewed prenatal imaging from 303 individuals with genetically confirmed AP-4-HSP enrolled in the Registry and Natural History Study for Early Onset Hereditary Spastic Paraplegia (NCT04712812). Four patients (covering SPG47, SPG50, SPG52) with fetal, perinatal, or early postmortem imaging available were selected for detailed neuroradiologic evaluation. Systematic assessment documented several structural anomalies, correlated with genotype and clinical progression.
    Results: Fetal imaging between 22 and 38 weeks' gestation revealed ventriculomegaly, corpus callosum hypoplasia, reduced periventricular white matter, and hippocampal under-rotation across all subtypes. The SPG52 patient exhibited additional severe features, including gyral immaturity and pontine/vermis hypoplasia. Postnatal follow-up demonstrated progressive white matter volume reduction and delayed myelination.
    Conclusions: This study demonstrates that fetal and perinatal brain MRI can detect early, consistent neurodevelopmental abnormalities in AP-4-HSP, reinforcing its classification as both a neurodevelopmental and neurodegenerative disorder. Integration of prenatal neuroimaging with molecular diagnostics could enable earlier recognition, family counseling, and access to emerging gene therapies. These findings support the incorporation of fetal brain MRI into diagnostic protocols for suspected neurogenetic conditions.
    Keywords:  adaptor protein complex 4; gene therapy; hereditary spastic paraplegia; neurodevelopment; prenatal imaging; thin corpus callosum
    DOI:  https://doi.org/10.1002/cns3.70035
  18. ACS Chem Neurosci. 2026 Mar 12.
      Neurodegenerative diseases are a major threat to global public health. Recent studies have revealed that mitochondrial DNA damage and the imbalance of protein homeostasis during aging constitute the core pathological basis of neurodegeneration. The resulting energy metabolism disorders are the common pathogenic hubs of multiple neurodegenerative diseases. In this review, we focus on representative neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, and Huntington's disease, and systematically discuss their pathology related to metabolic disorders. We introduce various energy compensation strategies: (1) rebuilding the energy supply by enhancing mitochondrial function; (2) implementing systemic metabolic remodeling; (3) supplementing alternative energy substrates; (4) utilizing direct energy delivery technology. This review also highlights the technical bottlenecks of existing energy compensation strategies, guiding future research on neurodegenerative diseases.
    Keywords:  eirect energy delivery; energy compensation; energy substrate supplementation; metabolic reprogramming; mitochondria-targeted therapies; neurodegenerative diseases
    DOI:  https://doi.org/10.1021/acschemneuro.5c00964
  19. Stem Cell Res Ther. 2026 Mar 13.
       BACKGROUND: The dentin-pulp complex (DPC) is composed of the odontoblastic layer and associated stromal components. It serves key functions in immunological homeostasis and tissue regeneration of dental tissues. Human dental pulp stem cells (hDPSCs) have emerged as pivotal cells for DPC regeneration. Current research frontiers primarily focus on developing novel strategies to increase the odontogenic differentiation potential and regenerative efficacy of hDPSCs. This study aims to boost the capacity of hDPSCs to regenerate DPC through mitochondrial transplantation.
    METHODS: Mitochondria were isolated from donor hDPSCs and transplanted into recipient hDPSCs (Mito-hDPSCs) in the same passage. Subsequently, cell viability and mitochondrial transplantation efficiency were evaluated via CCK-8, β-galactosidase staining, mitochondrial imaging, and flow cytometry. Furthermore, Mito-hDPSCs' metabolic capacity was assessed by mitochondrial membrane potential assays and cellular oxidative phosphorylation assays. Moreover, Alkaline Phosphatase (ALP) activity, Alizarin Red S (ARS) staining, RT-qPCR, and Western blotting (WB) were performed to assess Mito-hDPSC's odontogenic differentiation potential. Moreover, a nude mouse model was used to assess how Mito-hDPSCs induce DPC regeneration in vivo. RNA-Seq analysis was conducted to examine the expression of signaling pathways in Mito-hDPSCs. In addition, ALP, ARS, WB, and Ca2+ fluorescence staining were carried out to analyze the underlying mechanisms between mitochondria and the Ca2+/Transcription factor activating protein 2α (TFAP2A) signaling axis.
    RESULTS: The results revealed that mitochondrial transplantation enhanced the viability of Mito-hDPSCs. Furthermore, an increased mitochondrial transplant rate was observed at a recipient-to-donor cell ratio of 1:3. Moreover, Mito-hDPSCs demonstrated increased odontogenic differentiation and formed more dentin-pulp-like tissue in vivo. Ca2+ signaling and odontogenesis were significantly enriched in Mito-hDPSCs. TFAP2A was identified as a key transcription factor in the odontogenic differentiation of Mito-hDPSCs. Knockdown array revealed that mitochondrial transplantation effectively upregulated TFAP2A expression in Mito-hDPSCs. Furthermore, mitochondrial transplantation elevated intracellular Ca2+ concentration, which in turn increased TFAP2A expression.
    CONCLUSIONS: Mitochondrial transplantation may promote DPC regeneration by regulating the Ca²⁺/TFAP2A signaling axis in Mito-hDPSCs.
    Keywords:  Dentin-pulp complex regeneration; Human dental pulp stem cells; Mitochondrial transplantation; Odontoblast differentiation; Tissue engineering
    DOI:  https://doi.org/10.1186/s13287-026-04949-y