Frontiers in bioscience (Landmark edition)最新文献

Background: Long-QT syndrome type 2 (LQTS2), which is associated with life-threatening cardiac arrhythmias, is caused by pathogenic heterozygous loss-of-function mutations in the KCNH2 gene. This gene encodes the pore-forming Kv11.1 α-subunit of the ion channel that carries the rapid delayed rectifier potassium current (I_Kr). Pathogenic loss-of-function mutations reduce the amplitude of I_Kr, thereby prolonging the action potential (AP) of ventricular cardiomyocytes, and in turn, the QT interval of the electrocardiogram (ECG). The aim of the present in silico study was to test the extent to which allele-specific suppression ('silencing') of the mutant KCNH2 allele can alleviate the effects of dominant-negative LQTS2 mutations.

Methods: Two recent and comprehensive models of the electrical activity of a single human ventricular cardiomyocyte, i.e., the 'Bartolucci-Passini-Severi model as published in 2020' and the 'Tomek-Rodriguez model following the O'Hara-Rudy dynamic (ORd) model' (known as the BPS2020 and ToR-ORd models, respectively) were used to assess the effects of mild and severe LQTS2 mutations on the AP duration at 90% repolarization (APD₉₀) and the APD₉₀ restitution obtained with an S1-S2 pacing protocol.

Results: For severe mutations, the mutation-induced prolongation of the APD₉₀ at a stimulation rate of 1 Hz is reduced from 166% to 99% in the BPS2020 model and from 111% to 71% in the ToR-ORd model upon 70% suppression of the mutant allele. For mild mutations, this prolongation is reduced from 77% to 44% and from 57% to 34%, respectively. An even greater effect is observed when the mutant KCNH2 allele is inhibited by up to 90%, but the greater suppression is only marginal for mild mutations. The steepness of the mutant APD₉₀ restitution curves is considerably reduced upon suppression, which may exert an anti-arrhythmic effect.

Conclusions: Silencing of the mutant allele can substantially, but only partially, counteract the effects of mild or severe LQTS2 mutations on I_Kr. Allele-specific inhibition of the mutant KCNH2 allele alone is not sufficient to fully treat the effects of LQTS2 mutations and should be accompanied by a replacement gene therapy, creating a suppression-and-replacement ("SupRep") gene therapy.

Therapeutic strategies for ocular diseases are undergoing a transformative shift from symptom management to regenerative and disease-modifying approaches. This review highlights the development of neurotrophin receptor agonists-including recombinant nerve growth factor (NGF) (cenegermin), peptidomimetics (e.g., REC-0559, tavilermide), and synthetic microneurotrophins (BNN27, ENT-A010)-that target tropomyosin receptor kinases (TrkA/TrkB) and the p75 neurotrophin receptor (p75NTR) pathways to promote neuronal survival, synaptic plasticity, and tissue repair in neurotrophic keratitis, dry eye disease, and retinal degenerations. Parallel advances in peptide-based therapies address vascular and inflammatory pathologies: UPARANT and its derivatives modulate urokinase plasminogen activator receptor (uPAR)/formyl peptide receptor (FPR) signaling to inhibit angiogenesis and inflammation in diabetic retinopathy, whereas sphingosine 1 phosphate (S1P)-S1PR₃ pepducins and integrin antagonists (risuteganib, THR-687, OTT166) offer multi-targeted strategies to stabilize the blood-retinal barrier and mitigate neovascularization. Innovations in drug delivery, such as dendrimer-peptide conjugates, enhance the stability and bioavailability of these agents. Further, senolytic therapies (e.g., UBX1325, procyanidin C1) are emerging as a promising approach for age-related and diabetic retinal diseases by clearing senescent cells and attenuating senescence-associated secretory phenotype (SASP)-driven inflammation. Together, these approaches exemplify a paradigm of "mimicking nature to modulate vision", leveraging molecular insights to develop therapies that restore rather than merely preserve ocular function. While clinical validation is ongoing, the convergence of neurotrophic support, vascular modulation, and senescence targeting heralds a new era in precision ophthalmology.

Background: Chronic aerobic exercise is known to modulate oxidative stress, yet comparative analyses across multiple tissues remain limited. This study aimed to evaluate the effects of different training durations on oxidative damage and membrane fluidity in metabolically active tissues, including skeletal muscle, heart, and brain.

Methods: Forty male Sprague-Dawley rats were randomly assigned to four groups (n = 10/group): control (CON), and aerobic treadmill training for 1 week (1W), 4 weeks (4W), and 12 weeks (12W). Training consisted of four 60-minute sessions per week, alternating intensities at 35% and 80% of maximal velocity. Quadriceps skeletal muscle, heart, and brain were collected. Oxidative damage was assessed via malondialdehyde and 4-hydroxyalkenals (MDA + 4-HDA) and protein carbonyl content. Membrane fluidity was evaluated in plasma and mitochondrial membranes using fluorescence spectroscopy. Statistical analyses were performed using one-way analysis of variance followed by Tukey post-hoc tests.

Results: Aerobic training significantly reduced MDA + 4-HDA levels in skeletal muscle and heart compared with control values, with a downward trend in brain tissue that did not reach statistical significance. Protein carbonyls decreased significantly in skeletal muscle at 4W and 12W, but remained unchanged in heart and brain (despite lower mean values observed in all training groups compared with the control). Plasma membrane fluidity declined significantly in all tissues, especially at 4W and 12W, indicating structural remodeling. Mitochondrial membrane fluidity values were lower in heart and skeletal muscle across the different training groups, with statistically significant differences observed only and remarkably in skeletal muscle compared with control values; meanwhile, values remained stable in brain tissue. These findings reveal tissue-specific biochemical and biophysical adaptations to aerobic training.

Conclusions: Chronic aerobic treadmill training induces protective adaptations against oxidative stress in skeletal muscle, heart, and brain. The reduction in lipid peroxidation and protein oxidation, along with changes in membrane fluidity, reflects enhanced cellular resilience and structural integrity. These results support the role of sustained aerobic exercise as a non-pharmacological strategy to mitigate oxidative damage and promote tissue health. The rat model used provides translational relevance for understanding exercise-induced protection mechanisms.

Background: In recent years, drug-resistant influenza viruses have emerged frequently, making influenza a persistent and serious public health burden. Therefore, potential anti-influenza virus drugs are urgently needed. Nanobodies, variable domains of heavy-chain antibodies (VHHs), have the advantages of easy preparation, excellent solubility, deep tissue penetration, and weak immunogenicity; thus, they have broad application prospects in the fields of basic research and drug development. However, its short half-life and low stability limit its clinical therapeutic application. Fenobody is an engineered display platform with the ability to present multimerized nanobodies on the surface of ferritin to overcome these disadvantages and increase its potency.

Methods: In this study, we engineered a fenobody displaying multimerized VHH against haemagglutinin (HA) of influenza virus (A/California/07/2009(H1N1), pdm09) on the surface of ferritin by using the property of SpyTag to spontaneously bind to SpyCatcher, named ferritin-NP-VHH.

Results: Compared with VHH alone, ferritin-NP-VHH improved the cross-neutralizing activity, stability and affinity for influenza virus in vitro and prolonged its half-life in vivo.

Conclusions: These results suggest that the implementation of genetic engineering technology to construct multimerized anti-influenza virus nanoparticles provides new tools to control infection with influenza virus.

Background: Recent studies have identified impaired renal gluconeogenesis as a hallmark of chronic kidney disease. Triptolide is a natural compound widely used in China for the treatment of renal diseases. This study investigated whether triptolide mitigates renal fibrosis by promoting renal gluconeogenesis.

Methods: Renal fibrosis was induced in vivo by unilateral ureteral obstruction (UUO) surgery in mice. Transforming growth factor-β (TGF-β)-stimulated human kidney-2 (HK-2) cells were used as an in vitro model to investigate renal fibrosis. Metabolomics, western blotting, immunohistochemistry (IHC), and metabolic assays were performed to investigate the underlying mechanisms.

Results: Triptolide reduced the expression of several fibrotic markers in the kidneys of UUO mice. Metabolomic analysis revealed enhanced renal gluconeogenesis following treatment with triptolide, which was confirmed by analyzing gluconeogenic enzyme expression and lactate concentration in UUO kidneys. The pro-gluconeogenic effect of triptolide was further confirmed in TGF-β-stimulated HK2 cells. Inhibition of phosphoenolpyruvate carboxykinase 1 (PCK1) reversed the anti-fibrotic and pro-gluconeogenic effects of triptolide in TGF-β-stimulated HK2 cells. We further demonstrated that peroxisome proliferator-activated receptor-gamma co-activator 1 alpha (PGC1α) expression was downregulated in TGF-β-stimulated HK2 cells and UUO kidneys, and that triptolide reversed this downregulation. Moreover, the PGC1α inhibitor reversed the effect of triptolide on PCK1 expression and glucose metabolism. Finally, IHC analysis revealed that triptolide inhibited histone lactylation in UUO kidneys, which was associated with a decreased production of inflammatory factors and reduced macrophage infiltration.

Conclusions: Triptolide may inhibit renal fibrosis by increasing the PGC1α/PCK1 axis, thereby promoting renal gluconeogenesis. This cascade may reduce histone lactylation and renal inflammation, providing a mechanistic pathway for its anti-fibrotic effect.

Background: Aging is frequently accompanied by chronic, low-grade inflammation, often referred to as "inflammaging", which contributes to functional decline of multiple organs including the liver. The NLRP3 inflammasome has emerged as a key mediator of age-related inflammation; however, its pharmacological inhibition in the context of hepatic aging remains insufficiently explored. In this study, we investigated the effects of the selective NLRP3 inflammasome inhibitor MCC950 on inflammatory responses in the liver of aged mice.

Methods: Aged C57BL/6 mice (18 months old) were administered MCC950 intraperitoneally for four weeks, and liver tissues were analyzed for inflammatory and stress-related markers.

Results: MCC950 treatment significantly reduced hepatic expression of NLRP3, caspase-1 activation, and IL-1β production, accompanied by a decrease in proinflammatory cytokines such as p-STAT3. Histological analysis demonstrated attenuation of age-associated hepatic inflammatory infiltration and improved tissue architecture. Furthermore, MCC950 administration restored autophagy-related proteins (LC3B, p62) indicating broader protective effects on liver homeostasis.

Conclusion: These findings suggest that NLRP3 inflammasome inhibition with MCC950 alleviates age-associated hepatic inflammation and may represent a potential therapeutic strategy for mitigating inflammaging and preserving liver function in the elderly.

Background: Bronchopulmonary dysplasia (BPD) is a chronic lung disease in premature infants. Neonatal hyperoxia induces a BPD-like phenotype and lung cell senescence in rodents. In our 3-day hyperoxia model, senescent cells were predominantly lung macrophages, with their abundance peaking at postnatal day 7 (pnd7). However, the molecular and functional characteristics of these senescent macrophages remain undefined.

Methods: We reanalyzed a scRNA-seq dataset (GSE207866) generated from senescent lung cells isolated at pnd7 (SD7) following neonatal hyperoxia. Hierarchical clustering combined with manual annotation was used to compare transcriptional profiles with age-matched air-exposed controls (AirD7) and hyperoxia-exposed mice without senescent-cell enrichment (O2D7). Key molecular findings were validated by immunofluorescence. In vivo, neonatal mice received daily injections of the pyruvate dehydrogenase kinase inhibitor, dichloroacetate (DCA) from pnd4 to pnd6, and a senolytic cocktail consisting of quercetin and dasatinib from pnd4 to pnd14, following 3 days of hyperoxia exposure.

Results: Macrophages accounted for 65.90% of senescent cells in the SD7 group. Seven macrophage clusters were identified, enriched in M1-like and alveolar macrophage phenotypes. Two major clusters (clusters 0 and 1), together representing nearly half of all senescent macrophages, exhibited strong expression of genes associated with innate immunity, inflammation, and DNA damage responses. These clusters also showed a shift toward glycolysis, the pentose phosphate pathway, and glutamine metabolism, with reduced reliance on β-oxidation. Administration of DCA activated pyruvate dehydrogenase and attenuated hyperoxia-induced macrophage senescence and lung injury. Pathway enrichment analyses revealed enhanced metal-handling pathways, immune and stress signaling (including p38 mitogen-activated kinase, ataxia-telangiectasia mutated, and mechanistic target of rapamycin), apoptosis, and RNA regulatory processes. Conversely, genes involved in reactive oxygen species detoxification, DNA repair, phagocytosis, cytoskeletal organization, and cell adhesion were downregulated. Notably, reducing senescent cells by a senolytic cocktail during the alveolar stage mitigated hyperoxia-induced persistent lung injury.

Conclusion: Neonatal hyperoxia drives the emergence of a heterogeneous population of senescent macrophages characterized by metabolic reprogramming and dysregulated signaling pathways, which contribute to the development and persistence of lung injury.

Background: Escherichia coli is the leading cause of urinary tract infections (UTIs), and the increasing prevalence of antimicrobial resistance represents a major public health concern. The dissemination of multidrug-resistant uropathogenic E. coli (UPEC), frequently harboring transferable resistance determinants, poses an urgent clinical challenge.

Methods: This study investigated the prevalence of β-lactamase genes (blaTEM, blaSHV, blaCTX-M, blaCMY, and blaDHA) and plasmid-mediated quinolone resistance genes (qnrA, qnrB, qnrC, qnrD, and qnrS) in 86 imipenem-non-susceptible UPEC isolates using multiplex and single PCR assays. Gene distribution and co-occurrence were examined across E. coli phylogenetic groups, and pairwise associations were evaluated using correlation analysis. Principal component analysis (PCA) was applied to explore global relationships between antibiotic susceptibility profiles, extended-spectrum β-lactamase (ESBL) phenotype, and resistance determinants.

Results: Overall, 74.4% of imipenem-non-susceptible isolates carried at least one β-lactamase gene. blaTEM was the most prevalent (62.8%), followed by blaCMY II (12.8%). blaSHV, blaCTX-M group I, and blaCTX-M group II showed comparable prevalence (10.5% each). The B2 phylogroup showed the greatest diversity of β-lactamase profiles, with phylogroup E representing the second most frequent reservoir. Among quinolone resistance genes, qnrB was the most prevalent (20.9%), followed by qnrD (5.8%), qnrS (4.7%), qnrA (3.5%), and qnrC (1.2%). All qnrC-positive isolates were resistant to all tested quinolones. No statistically significant associations were observed between β-lactamase genes and qnr genes. Significant within-class correlations were detected for blaCTX-M group II-blaCMY II (φ = 0.893, q = 9.33 × 10^-9) and qnrC-qnrA (φ = 0.57, q = 0.374).

Conclusions: A high prevalence of β-lactamase and qnr determinants was observed among imipenem-non-susceptible UPEC, primarily driven by blaTEM and qnrB, frequently detected in B2 isolates. The co-occurrence and correlation of multiple resistance genes highlight the complexity of resistance architectures and underscore the need for ongoing molecular surveillance and strengthened antimicrobial stewardship to limit the dissemination of resistant UPEC.

Background: In recent years, immunotherapy has gained increasing prominence in the treatment of hepatocellular carcinoma (HCC). However, effective immune-related biomarkers for HCC remain limited. In this study, both transcriptomic data and clinical information on HCC were obtained from The Cancer Genome Atlas (TCGA) database.

Methods: The TIMER and GEPIA databases were used to validate the association between WDR4 expression and immune infiltration. Additionally, clinical and pathological data from patients who underwent single-agent immunotherapy for HCC were collected from Hunan Provincial People's Hospital (The First Affiliated Hospital of Hunan Normal University). The relationship between WDR4 expression levels, clinical pathological data, and patient prognosis was assessed using the Kruskal-Wallis test and Kaplan-Meier survival curve analysis. Spearman's correlation analysis was utilized to confirm the relationship between WDR4, CD68, and PD-L1 in HCC tissue.

Results: WDR4 was significantly upregulated in HCC tissues compared to para-carcinoma tissues (p < 0.001) and exhibited strong diagnostic potential. WDR4 expression showed significant associations with various immune cells, including macrophages (p < 0.001). Kaplan-Meier survival analysis revealed that patients with high WDR4 expression had shorter postoperative progression-free survival in the context of immunotherapy. Data from 37 patients who underwent postoperative single-agent immunotherapy for HCC demonstrated a significant correlation between WDR4 expression levels and disease-free survival (DFS), with strong statistical significance (log-rank p < 0.001).

Conclusions: WDR4 shows elevated expression in HCC tissues and is associated with immune infiltration, establishing it as a prognostic biomarker in HCC. Furthermore, the positive correlation observed between WDR4 and CD68, as well as PD-L1 (CD274), underscores its potential as a guiding factor in immunotherapeutic approaches for HCC.