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The molecular mechanism of cuproptosis and research progress in pancreatic diseases.

PURPOSE: Cuproptosis has been proven to be a novel mode of cell death, distinct from other types of cell death such as necrosis, ferroptosis, pyroptosis, and apoptosis. This study aims to systematically review the molecular mechanisms of cuproptosis in recent years and its research progress in pancreatic diseases. METHODS: By searching PubMed and Web of Science databases, 113 key literatures were included for thematic analysis, covering the molecular mechanism of cuproptosis and its role in the occurrence and development of pancreatic cancer, acute and chronic pancreatitis, diabetes, pancreatic cyst, pancreatic injury and pancreatic neuroendocrine tumor. RESULTS: Cuproptosis refers to the accumulation of copper ions in cells, which leads to instability of ferritin and aggregation of acylated proteins, resulting in oxidative stress-related cell death. Recent studies have shown that cuproptosis plays an important role in the occurrence and development of various pancreatic diseases, such as pancreatic cancer, acute and chronic pancreatitis, diabetes, pancreatic cysts, pancreatic injuries and pancreatic neuroendocrine tumor. The inducers of cuproptosis, such as disulfiram, chloroquinolones, and perilla phenols, alleviate pancreatic cancer by promoting cell cuproptosis. Copper chelators such as tetraethylenepentamine and tetrathiomolybdate promote the recovery of pancreatic injury by inhibiting cell cuproptosis. CONCLUSIONS: Cuproptosis plays a crucial role in the pathogenesis of pancreatic diseases. Further research on the cuproptosis pathway may become a potential target for the treatment of pancreatic diseases.

Animals

Trends in demographic and health survey publications based on a bibliometric analysis.

BACKGROUND: The Demographic and Health Surveys (DHS) Program, launched in 1984, provides high-quality population health data that underpins a vast body of global health research. However, the scale and growth patterns of DHS-based publications remain underexplored, particularly as donor funding uncertainties threaten program sustainability. OBJECTIVE: We examine temporal trends in DHS-based research output from 1984 to 2025, quantifying growth patterns and publication delays to inform understanding of the program's global research expansion. METHODS: A systematic bibliometric review was conducted following PRISMA guidelines across PubMed, Scopus, Web of Science, Dimensions, Wiley, and CINAHL. Eligible peer-reviewed articles using DHS data between 1984 and 2025 were identified. Annual publication counts were analyzed, segmented regression identified growth inflection points, and timeliness was assessed by calculating lag between survey completion and publication. RESULTS: Over 10,000 DHS-based publications were identified. Annual output rose from isolated studies in the 1980s to several hundred annually by the 2010s. Segmentation analysis revealed two rapid growth phases: a 56-publications/year increase from 2004-2012, and a 71-publications/year increase from 2012 to 2024. Despite this growth, median lag from survey completion to publication remained approximately 5 years, with only a modest recent improvement (Kendall's &#x3c4;&#x2009;=&#x2009; -0.623, p&#x2009;<&#x2009;0.001). CONCLUSION: DHS data have fueled exponential growth in global health research over four decades, confirming their vital role in evidence generation. However, persistent publication delays highlight the need to shorten the pathway from data collection to dissemination through strengthened research capacity in low- and middle-income countries. Sustained funding is essential to maintain this critical evidence source.

Bibliometrics

Pollution characteristics and health risks of PAHs and OPAHs in PM2.5 of an inland basin city in China under the influence of the clean air action plan.

Since the implementation of China's Clean Air Action, remarkable progress has been made in air pollution control, with continuous air quality improvement in Xi'an, a typical inland basin city in the Fenwei Plain. To clarify winter organic aerosol pollution variations and pinpoint targeted control needs under policy regulation, this study investigated PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) and oxygenated derivatives (OPAHs) in winter Xi'an, focusing on pollution levels, chemical compositions, source contributions, meteorological impacts, regional transport and health risks. Historical comparison showed generally lower wintertime PAH concentrations in Xi'an during the period of China's clean-air actions. PMF results indicated mixed source influences on PAHs and OPAHs, with biomass-burning-related mixed combustion showing the largest contribution. During haze episodes, absolute concentrations of both PAHs and OPAHs increased; the increase was statistically significant for OPAHs but not for parent PAHs, while 4-5 ring PAHs and BcdPQ dominated the PAH and OPAH profiles, respectively. Meteorological variability, particularly synoptic pressure patterns, was strongly associated with pollutant concentrations, and regional pollution was dominated by in-basin accumulation combined with short-range transport from northern Shaanxi industrial zones. Haze periods exhibited higher toxic-equivalent concentrations, with OPAHs, particularly BcdPQ, dominating the toxicity-equivalent burden. Screening-level ILCR estimates generally remained below 10&#x207b;4 but increased during haze episodes, especially for adult and elderly groups. In conclusion, China's clean air actions have coincided with lower wintertime PAH pollution, but stronger control of residential biomass and other solid-fuel combustion, traffic emissions, and OPAH formation remains necessary in the Fenwei Plain.

China

Resistance versus concurrent training with three assigned protein targets in middle-aged and older women: a randomized 2 &#xd7; 3 factorial trial.

BACKGROUND: Evidence is limited regarding whether assigned protein targets modify responses to resistance training (RT) alone or to the same RT program plus cycling (concurrent training [CT]) in middle-aged and older women. This randomized 2&#x2009;&#xd7;&#x2009;3 factorial trial examined bioelectrical impedance analysis (BIA)-derived skeletal muscle mass (SMM; primary outcome), other body composition outcomes, muscular and functional performance, and cycle-derived estimated VO&#x2082;max. METHODS: In this randomized 2&#x2009;&#xd7;&#x2009;3 factorial trial, 108 women aged 40-77 years were assigned to 12 weeks of supervised RT or CT (identical RT followed by cycling) and protein targets of 0.8, 1.6, or 2.2 g&#xb7;kg-1&#xb7;d-1. Baseline-adjusted ANCOVA tested training&#x2009;&#xd7;&#x2009;protein interactions and marginal training and protein effects. Complete-case analyses included 83 participants. RESULTS: For SMM, no training-condition&#x2009;&#xd7;&#x2009;protein-target interaction (p&#x2009;=&#x2009;0.856), marginal protein-target effect (p&#x2009;=&#x2009;0.726), or marginal training-condition effect (p&#x2009;=&#x2009;0.273) was detected. CT had a lower baseline-adjusted week-12 BFP than RT (adjusted difference, -2.04 percentage points; 95% CI, -2.94 to -1.14; p&#x2009;<&#x2009;0.001). RT had a higher baseline-adjusted week-12 leg-press estimated 1-RM than CT (CT - RT: -6.68 kg; 95% CI, -8.32 to -5.04; p&#x2009;<&#x2009;0.001), whereas CT had a higher baseline-adjusted week-12 cycle-derived estimated VO&#x2082;max (adjusted difference, 4.53 mL&#xb7;kg-1&#xb7;min-1; 95% CI, 3.80 to 5.25; p&#x2009;<&#x2009;0.001). No detectable marginal protein-target effects or training-condition&#x2009;&#xd7;&#x2009;protein-target interactions were observed for the key secondary outcomes. CONCLUSIONS: No detectable differences in SMM or key secondary outcomes were attributable to assigned protein target. Compared with RT, CT favored estimated aerobic fitness and BFP, whereas RT favored leg-press strength. Because CT included additional cycling and greater exercise exposure, these differences cannot be attributed solely to training modality. Null protein findings do not establish equivalence among doses.

Humans

Pathogenic Variants in HEPACAM Alter Protein Localization and Interactome in Astrocytes of the Developing Mouse Cortex.

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare leukodystrophy characterized by early-onset macrocephaly, white matter edema, seizures, and motor and cognitive decline. Approximately 25% of MLC patients carry HEPACAM pathogenic variants, many of which are dominant missense variants causing remitting MLC Type 2b. HEPACAM encodes hepatic and glial cell adhesion molecule (hepaCAM), also known as GlialCAM, an astrocyte-enriched transmembrane protein with important roles in astrocyte territory establishment, gap junction coupling, branching organization, synaptic function, and development of the gliovascular unit. The molecular mechanisms through which pathogenic variants in HEPACAM alter hepaCAM protein function in&#xa0;vivo and facilitate MLC pathogenesis during brain development remain largely unknown. Here, we used new viral tools and proximity-based proteomics to examine how three different dominant pathogenic variants alter hepaCAM subcellular localization and protein interactome in astrocytes of the developing mouse cortex. We found dramatic changes in hepaCAM distribution throughout the astrocyte, which were common to all mutants tested. We also observed significant changes in protein interactome between wild type and mutant hepaCAM, including decreased association with previously described hepaCAM-interacting proteins Connexin 43 and CLC-2. Moreover, we identified the epilepsy-associate potassium channel KCNQ2 as a novel hepaCAM interaction partner and found reduced association between KCNQ2 and pathogenic variants. Collectively, our data provide new insights into hepaCAM protein function in astrocytes during brain development, reveal altered protein dynamics of pathogenic variants, and provide a new resource to explore the molecular underpinnings of MLC pathogenesis.

Animals

Accurate quantification of canine mitochondrial DNA copy number from canine blood and brain samples.

Acute brain injury is difficult to evaluate in veterinary medicine and tools to investigate the potential involvement of mitochondrial involvement are limited. The brain is highly enriched in mitochondria and contains thousands of copies of mitochondrial DNA (mtDNA) per cell, but robust methods for quantifying mitochondrial DNA copy number (mtDNA-CN) in canine tissues are lacking. We describe the development of a quantitative real-time PCR assay for absolute measurement of mtDNA-CN which was validated in canine blood and brain tissue. To minimize amplification of nuclear mitochondrial insertion sequences (NumtS) and repetitive regions, species-specific oligonucleotide primers were designed following in silico genomic filtering. The assay was applied to a small pilot cohort comprising blood samples from dogs with and without acute brain injury (n&#xa0;=&#xa0;4-6 per group) and cerebral cortex samples (n&#xa0;=&#xa0;1 per group) to assess feasibility and biological plausibility. In non-brain injury dogs, blood mtDNA-CN ranged from 98 to 288 copies per nuclear genome (mean 193&#xa0;&#xb1;&#xa0;72), while values in brain-injured cases ranged from 163 to 228 copies per genome (mean 200&#xa0;&#xb1;&#xa0;33). Cerebral cortex samples exhibited higher mtDNA-CN than blood, consistent with known tissue-specific mitochondrial enrichment. In a single brain-injured case with serial sampling, mtDNA-CN increased over five days. This study presents a validated assay and pilot data for mtDNA-CN quantification in canine samples. While not powered for biomarker evaluation, this method may enable future studies of mitochondrial dynamics in canine brain injury and metabolic disease.

Animals

Can't see the forest for the trees: The influence of marker type on inferred phylogenetic relationships in a cosmopolitan bat genus.

Fine-resolution information on species relationships and biological diversity is critically needed to guide conservation efforts amidst rapid environmental changes. Systematics, which forms the foundation of this knowledge, has been revolutionized by phylogenomics, utilizing genome-scale datasets. However, the use of diverse marker types, non-comparable taxon sampling, and outgroup selection can lead to conflicting phylogenetic hypotheses. These inconsistencies complicate study comparisons and hinder our ability to assess marker-specific impacts on phylogenetic resolution. The phylogenetic reconstruction of the bat genus Myotis, encompassing over 140 species and characterized by a rapid radiation in the last 20 million years, has been particularly influenced by these challenges. Achieving phylogenetic resolution in Myotis is particularly complex due to subtle interspecific differences in both morphological and molecular traits. Mitochondrial and nuclear markers often produce discordant trees, influenced by hybridization, introgression, and methodological variations. In this study, we employed a consistent taxonomic sample set of 44 Myotis taxa to evaluate the impact of five different genetic marker types on phylogenetic reconstruction. We observed significant discordance between topologies derived from conserved nuclear and mitochondrial markers and found that transposable elements were inadequate for resolving relationships across the entire genus. Our results also clarify the placement of previously problematic taxa within the genus. These findings emphasize the importance of aligning genetic marker choice with specific phylogenetic questions and highlight the influence of taxonomic and methodological variation on phylogenomic outcomes. This work provides a framework for improving phylogenetic inference in rapidly radiating groups and enhances our understanding of evolutionary history in Myotis.

Animals

Effects of 12 weeks of resistance and concurrent training with graded protein intakes on lipid profile, kidney and liver biomarkers in middle-aged to older women.

PURPOSE: To examine secondary lipid, kidney-related, and liver-enzyme responses to three protein intakes during resistance training (RT) alone or the same RT plus cycling (CT) in middle-aged to older women. METHODS: In this randomized 2&#xd7;3 factorial trial, 108 women aged 40-77 years were assigned to RT or CT and 0.8, 1.6, or 2.2 g kg-1 d-1 protein for 12 weeks. This complete-case secondary analysis included 83 participants. Linear mixed-effects models tested Time &#xd7; Training, Time &#xd7; Protein, and Time &#xd7; Training &#xd7; Protein effects, with false-discovery-rate-adjusted omnibus tests and Holm-adjusted contrasts. RESULTS: Triglycerides, total cholesterol, LDL-C, and apolipoprotein B decreased and HDL-C increased in all conditions. Lipid changes differed by protein condition, and several were more favorable with CT; however, CT comprised RT plus additional cycling and greater exercise exposure. Urea, blood urea nitrogen, creatinine, the blood urea nitrogen-to-creatinine ratio, and cystatin C increased, whereas three eGFR estimates decreased. Responses differed mainly between 0.8 and the two higher protein conditions, with little evidence of differences between 1.6 and 2.2 g kg-1 d-1. ALT, AST, and GGT differed by protein condition; AST and GGT also showed training-dependent responses. CONCLUSIONS: The dietary and exercise interventions modified lipid and clinical-chemistry responses. Because energy and food composition were not fully matched and CT added cycling to RT, the findings do not isolate protein dose or exercise modality. Changes in eGFR estimates and liver enzymes do not establish organ injury or long-term safety.

Humans

Chemotherapy-Induced Nausea and Vomiting in Early Breast Cancer Patients Receiving Adjuvant Chemotherapy With Fluorouracil, Epirubicin, Cyclophosphamide Followed by Docetaxel Versus an Anthracycline-Free Regimen With Docetaxel, Cyclophosphamide-Results From a Randomized Clinical Trial.

Chemotherapy-induced nausea and vomiting (CINV) remains an important side effect despite new antiemetic drugs. This study tried to understand the occurrence of CINV in patients receiving two different chemotherapy regimens. As part of the randomized controlled clinical trial SUCCESS C (NCT00847444), 1582 of the 3463 patients completed CINV diaries. Patients were randomized to receive either chemotherapy with FEC (5-fluorouracil, epirubicin, cyclophosphamide followed by docetaxel) or TC (docetaxel, cyclophosphamide). CINV was evaluated hourly using a specially designed questionnaire. Endpoints of the study were complete response (no emesis) and total control (no nausea and no emesis) and were assessed with Kaplan-Meier curves and Cox regression analyses over three chemotherapy cycles. Eight hundred fourteen patients received FEC and 768 received TC; patients and tumor characteristics were similar in both groups. Patients receiving FEC had significantly more nausea and vomiting, with the main difference in the first 12&#x2009;h. In the first cycle, the 0-12-h nausea/emesis-free rates were 70%/41% for FEC and 91/76% for TC. By 24&#x2009;h after chemotherapy, the rates were 65%/33% (FEC) and 85%/60% (TC). The differences were similar in cycles 2 and 3. The detailed analysis of CINV in the study is unique and paves the way for modern CINV analysis of new therapeutics such as antibody-drug conjugates.

Adult

Optimized AAV5-RPGR ORF15 Gene Therapy Rescues Photoreceptor Structure and Function in X-Linked Retinitis Pigmentosa Mouse Model.

PURPOSE: To develop and evaluate an rAAV5-based gene therapy vector expressing an optimized human RPGR ORF15 transgene (rAAV5-RPGR) for the treatment of X-linked retinitis pigmentosa caused by RPGR mutations, addressing the challenges of cloning the unstable wild-type ORF15 sequence. DESIGN: This was a prospective experimental study. SUBJECTS: This was an animal study. METHODS: An optimized RPGR ORF15 sequence was designed to eliminate problematic secondary structures and cryptic splice sites. In vitro expression was validated in HEK 293T and photoreceptor-like 661 W cells. A complete Rpgr knockout mouse model (Rpgr-knockout [KO]) was generated and characterized phenotypically. Therapeutic efficacy was assessed in Rpgr-KO mice via subretinal injection of rAAV5-RPGR at low (1 &#xd7; 10&#x2079; vg/eye), medium (3 &#xd7; 10&#x2079; vg/eye), or high (1 &#xd7; 10&#xb9;&#x2070; vg/eye) doses. Structural and functional outcomes were evaluated at 12- and 14-month postinjection. Short-term safety was assessed in rabbits 1 month after subretinal injection. MAIN OUTCOME MEASURES: Level of RPGR protein expression and Protein isoform profile (elimination of truncated isoforms), Cellular localization of transgene expression and Dose-dependence of expression, outer nuclear layer thickness, and electroretinography parameters. RESULTS: (1) The optimized vector increased RPGR protein expression 3.3-fold in vitro compared to wild-type and eliminated truncated isoforms. (2) Subretinal delivery of rAAV5-RPGR in mice demonstrated dose-dependent transgene expression localized correctly to photoreceptor inner segments. (3) In Rpgr-KO mice, high-dose treatment significantly preserved outer nuclear layer thickness at the injection site (42% greater than controls at 14 months, P < .01) and central retina (P < .05), reduced aberrant rhodopsin mislocalization (P < .01), and partially restored retinal function. ERG showed significantly improved scotopic a-wave (&#x2265;100 vs <90 &#xb5;V in controls at 10 cd&#xb7;s/m&#xb2;) and photopic b-wave amplitudes (49-66 vs 31-46 &#xb5;V at 30 cd&#xb7;s/m&#xb2;) in treated mice. (4) No vector-related toxicity was observed in rabbits. CONCLUSIONS: rAAV5-RPGR mediated efficiently, targeted expression of optimized RPGR-ORF15, significantly preserved photoreceptor structure and function in a severe X-linked retinitis pigmentosa mouse model, and demonstrated a favorable safety profile. This study provides preclinical proof-of-concept for RPGR-targeted gene replacement therapy.

Animals

The role of transposable elements-endogenous retroviruses in embryonic development and regeneration.

Endogenous retroviruses (ERVs) are dynamically regulated across the lifespan and can function as context-dependent components of host gene-regulatory networks. During embryonic development, selected ERV-derived elements are co-opted to support zygotic genome activation, lineage specification, and placental development. In adult tissues, ERV-derived sequences can contribute to tissue and immune homeostasis, whereas potentially disruptive ERV activity is constrained by epigenetic mechanisms. During regeneration and somatic cell reprogramming, ERV and broader transposable-element programs undergo transient, locus-specific remodeling. In aging, the weakening of epigenetic and nuclear restraint can promote aberrant ERV derepression, inflammation, and functional decline. This review summarizes the diverse roles of ERVs across these contexts and discusses the challenges of defining locus-specific functions, resolving repetitive sequences, and developing safe ERV-targeted interventions.

Endogenous Retroviruses

Bergamottin, a bioactive component of bergamot: dual inhibition of Japanese encephalitis virus internalization and genome replication.

Japanese encephalitis virus (JEV) is associated with high mortality and severe neurological sequelae, and existing prevention and control strategies remain insufficient. Therefore, the development of novel antiviral agents is of critical public health importance. This study systematically evaluated the antiviral activity and underlying mechanism of bergamottin, a natural product. Bergamottin exhibited significant dose-dependent inhibitory effects against JEV in multiple cell lines, including BHK-21, HuH-7, and Vero cells, demonstrating potent antiviral efficacy. Mechanistic investigations revealed that bergamottin primarily targeted the internalization and replication stages of the JEV life cycle, thereby effectively suppressing viral proliferation. Additionally, adaptive mutation screening indicated that the D389G mutation in envelope protein E confers drug resistance by potentially changing E protein conformation or reducing endocytic efficiency. In vivo experiment, bergamottin significantly reduced viral loads in mouse brain tissue and effectively improved the survival rate of infected mice. Our findings indicated that bergamottin exerted antiviral activity by dual targeting of key steps in the viral life cycle, making it a highly promising candidate for anti-JEV therapy. Further exploration of the antiviral properties of bergamottin is expected to facilitate its clinical development as a treatment for JEV infection.

Animals

Understanding FDA's reasons for nonapproval: A systematic review of complete response letters in cell and gene therapy.

BACKGROUND AIMS: Cell and gene therapy products face unique regulatory challenges due to their biological complexity and the stringent expectations for manufacturing control, analytical testing, and clinical assessment. As the pipeline grows, understanding the drivers of FDA non&#x2011;approval is increasingly important for improving first&#x2011;cycle success and reducing development delays. In this study, we aimed to characterize the frequency and impact of refuse&#x2011;to&#x2011;file actions, major amendments, and complete response letters issued for biologics licensing applications; and to identify recurring patterns of deficiencies contributing to delayed approval. METHODS: Publicly available documents were extracted from the FDA website. Data from each approved cell and gene therapy product's regulatory history-including complete responses, major amendments, inspection timing, and cited deficiencies-were compiled and categorized across clinical, quality, and labeling domains. RESULTS: Analysis showed that informational deficiencies were common across modalities. Major amendments occurred in roughly half of applications, and complete responses had the most significant impact. Quality deficiencies appeared in all complete responses and were the predominant barrier, while clinical and labeling issues were less frequent but meaningful when present. CONCLUSION: Overall, these findings highlight the need for proactive FDA engagement, comprehensive readiness, and early inspection preparation to reduce regulatory risk and improve first cycle approval outcomes.

Humans

Plasticity of hepatic metabolism in Arctic char (Salvelinus alpinus) in response to cyclic hypoxia.

The emergence of cyclic hypoxia puts aquatic organisms' homeostasis under significant strain. Energetic metabolism as well as protein synthesis and folding are particularly altered during hypoxia, while reoxygenation imposes an oxidative challenge. Currently, little is known about how hypoxia-sensitive organisms respond to large oxygen fluctuations. Our previous work on Arctic char revealed that this salmonid, despite being strongly affected by acute hypoxia and reoxygenation (H/R), can successfully reestablish homeostasis, notably through adjustments to hepatic mitochondrial metabolism. However, the mechanisms underlying this acclimation remain poorly understood. We hypothesized that Arctic char remodel their hepatic proteome to optimize energy metabolism, reorganize oxygen-demanding pathways, and maintain cellular homeostasis during repeated H/R cycles. By exposing Arctic char to two or fifteen days of diel cyclic hypoxia, we confirmed this species' limited capacity to respond to acute H/R. Nevertheless, after fifteen cycles, fish adjusted their energetic metabolism through coordinated regulation of carbohydrate and lipid pathways and upregulation of amino acid metabolism. Mitochondrial metabolism was strongly reorganized, particularly at the ubiquinone-Complex III interaction level, alongside adjustments in proline utilization and protein processing. Moreover, protein processing and folding pathways were stimulated in both mitochondria and the endoplasmic reticulum. However, chronic cyclic hypoxia may still promote non-mitochondrial ROS production, DNA replication stress, and impaired immune function. This study highlights how a hypoxia-sensitive fish progressively reorganizes its metabolism and oxygen-demanding pathways to establish a phenotype adapted to chronic cyclic hypoxia, while also revealing the physiological costs associated with this acclimation.

Animals

Mechanisms of Hematopoietic Stem Cell Aging and Emerging Rejuvenation Strategies.

Hematopoietic stem cell (HSCs) aging is a complex biological process driven by both cell-intrinsic alterations and extrinsic cues from the bone marrow niche. Understanding these mechanisms is critical for developing therapies against aging-related hematopoietic disorders. This review synthesizes recent advances in the molecular mechanisms underlying HSCs aging, including microenvironmental aging, genomic instability, epigenetic dysregulation, mitochondrial dysfunction, and aberrant nuclear mechanotransduction. We summarize that the functional decline of HSCs during aging drives a compensatory expansion of the phenotypically defined stem cell pool, leading to an aberrant increase in cell number. We also highlight aging-associated HSCs heterogeneity, including CD150high and P-selectin-positive subsets that enrich for myeloid-biased or functionally compromised HSCs states while emphasizing that surface phenotype alone may not fully indicate functional rejuvenation. Finally, we discuss emerging rejuvenation strategies-including targeting myeloid-biased HSCs, modulating inflammatory pathways, and implementing epigenetic or metabolic interventions-supported by cutting-edge technologies such as single-cell multi-omics, gene editing, and computational modeling. These approaches hold promise for counteracting age-related hematopoietic decline and restoring immune competence.

Humans

Muscle mechanical and architectural adaptations in response to different endurance training modalities in older adults.

INTRODUCTION: This study examined the effects of various cycling endurance training modalities, matched for total workload, on muscle mechanical and architectural characteristics in older adults. METHODS: Fifty healthy participants (25 females, 59-79&#xa0;yrs) were randomly assigned to five age and sex matched groups: one control and four workload-matched training groups (moderate-intensity continuous, heavy-intensity continuous, high-intensity interval, and heavy-intensity continuous in eccentric cycling). Training consisted of three weekly sessions over 8&#xa0;weeks, with evaluations conducted at the beginning and end of the intervention with maximal voluntary isometric contractions at five different knee angles (90, 75, 60, 45, 30&#xb0;) and maximal concentric and eccentric isokinetic contractions at five different knee angular velocities (45, 90, 150, 210, 250&#xb0;/s). Maximum voluntary isometric torque (Tmax) and optimal knee angle (KAopt) were obtained from the isometric contractions; eccentric torque (Tecc) and maximum concentric knee angular velocity (Vmax) were obtained from the isokinetic contractions. The muscle architecture of vastus lateralis (VL) at rest (muscle thickness, pennation angle, and fascicle length) was investigated as well. RESULTS: No statistical differences were detected between groups or time points in VL architecture, in KAopt and in Vmax. A main effect of time was observed for Tmax (p&#xa0;<&#xa0;0.001, &#x3b7;2p&#xa0;=&#xa0;0.458) and Tecc (p&#xa0;=&#xa0;0.002, &#x3b7;2p&#xa0;=&#xa0;0.191) in all the investigated training groups. The within-group comparisons indicate significant increases in Tmax in the training groups, but not in the control group. CONCLUSIONS: Commonly applied endurance exercises improve muscle mechanical capacity (Tmax and Tecc) in older adults, with no structural (architectural) muscle remodelling, when matched for workload.

Humans

Pathogenic properties of myasthenia gravis AChR autoantibodies associate with clinical response to efgartigimod.

BACKGROUND: Efgartigimod, a neonatal Fc receptor (FcRn) blocker, effectively reduces total IgG, including pathogenic acetylcholine receptor (AChR) autoantibodies in myasthenia gravis (MG); however, clinical responses vary. To investigate this variability, we studied how efgartigimod impacts AChR-specific autoantibody profiles and associated pathogenic mechanisms, including complement activation, AChR internalisation and ACh-binding site blockade. METHODS: Serum samples (N=150) were sourced from 50 AChR autoantibody-positive generalised MG patients participating in the phase 3 ADAPT study, randomised to receive efgartigimod (N=40) or placebo (N=10) in cycles of 4-weekly infusions. Samples were collected at baseline, day 29 and day 57 during the first cycle. Live cell-based assays quantified AChR-specific IgG subclasses and isotypes and assessed their capacity to mediate pathomechanisms. RESULTS: Efgartigimod decreased all detectable AChR-specific IgG subclasses. At baseline, AChR autoantibody-mediated C3b deposition, AChR internalisation and ACh-binding site blockade were detected in 42 (84%), 41 (82%) and 10 (20%) patients, respectively. After 4-weekly infusions of efgartigimod, the magnitude of all three pathomechanisms was significantly decreased. However, the extent of this reduction varied across individuals. Double responders on both MG-activities of daily living and quantitative MG scores demonstrated a greater reduction in complement activity and AChR internalisation compared with patients who responded on only one score or were double non-responders. In addition, efgartigimod reduced IgG-dependent IgM binding to AChR. CONCLUSIONS: These findings suggest that clinical efficacy may be more closely associated with functional modulation of the AChR-specific autoantibodies than with their absolute quantity alone. These results support the evaluation of mechanistic pathway monitoring as a potential strategy to predict or guide efgartigimod treatment response.

Humans

Mitochondrial translocation of DNMT3L suppresses oxidative phosphorylation and restrains megakaryopoiesis.

DNMT3L, a catalytically inactive member of the DNA methyltransferase family, is identified here as a negative regulator of megakaryopoiesis. In K562 cells undergoing PMA-induced megakaryocytic differentiation, DNMT3L protein levels declined progressively, and shRNA-mediated depletion enhanced differentiation, whereas overexpression attenuated it. Consistent with these findings, Dnmt3l-knockout mice exhibited elevated peripheral blood platelet counts and expanded bone marrow megakaryocytes. Mechanistically, megakaryocytic differentiation triggered rapid mitochondrial translocation of DNMT3L within 6&#xa0;h; mitochondrial DNMT3L suppressed oxidative phosphorylation (OXPHOS) capacity and ATP production and downregulated mitochondrial-encoded genes spanning Complex I, III, IV, and ATP synthase, without altering mitochondrial DNA copy number. This metabolic suppression was mediated through compartment-specific remodeling of DNMT3L-containing protein complexes: upon differentiation, DNMT3L selectively dissociated from DNMT1 and DNMT3B in mitochondria, relieving the repressive constraint on OXPHOS, whereas in the nucleus DNMT3L remained associated with DNMT3A, which concomitantly accumulated during differentiation. These findings reveal a previously unrecognized mechanism by which a catalytically inactive epigenetic co-regulator spatially redistributes to coordinate mitochondrial metabolic output with nuclear epigenetic control, thereby facilitating terminal megakaryocytic maturation.

Animals