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PubMed2026

Genetic regulation of CPEB3-mediated alternative polyadenylation associated with survival of patients with hepatocellular carcinoma.

BACKGROUND: Alternative polyadenylation (APA) is a key post-transcriptional mechanism that regulates gene expression by modulating 3'UTR length, its dysregulation has been implicated in carcinogenesis. How genetic variants influence APA to affect hepatocellular carcinoma (HCC) prognosis remains unclear. METHODS: Prognosis-APA quantitative trait loci (apaQTL) were performed using genotype and APA profiling from TCGA data. A two-stage survival analysis in 848 Chinese and 369 TCGA LIHC patients and functional validation were used to identify prognostic apaQTL in HCC progression. RESULTS: A total of 2,025 and 817 significant APA events were identified in Chinese and TCGA cohort, respectively. Besides, 859 events were associated with poor prognosis in HCC and enriched in RNA splicing / metabolism pathways. We detected 32,034 significant apaQTLs, predominantly enriched in 3'UTRs and RBP-binding regions. CPEB3 was prioritized as a key APA regulator RBP; its low expression correlated with poor patient survival and promoted proliferation, migration, and invasion in HCC cells. Notably, a functional apaQTL variant rs2037547, located in GSK3B and mediated by CPEB3, demonstrated a poor survival of HCC patients in both cohort (pooled HR=1.29, p=0.016). Mechanistically, rs2037547 promoted aberrant APA at proximal poly(A) sites of GSK3B through CPEB3, leading to increased expression of short 3'UTR isoform. This regulatory alteration enhanced HCC cell proliferation, invasion, and migration, and contributed to HCC progression. CONCLUSION: These findings elucidated the distinct role of apaQTL-mediated APA dysregulation in HCC prognosis, providing insights for prognostic stratification and potential targets for personalized therapy in HCC.

RNA-binding proteins↗
PubMed2026

Algae-to-host horizontal gene transfer in Paramecium bursaria is associated with host adaptation during endosymbiosis.

Paramecium bursaria maintains a stable endosymbiosis with green algae, yet the evolutionary consequences of this association remain unclear. Here, we screened the host genome for algal-derived horizontally transferred genes (HTGs) using a lineage-aware workflow designed to detect horizontal gene transfer (HGT) between two defined lineages. We identified 16 candidate HTGs, including four putative newly transferred genes and 12 homologous transferred genes, most of which were functionally associated with redox homeostasis and metabolism. Five HTGs showed symbiosis-dependent expression. RNAi knockdown of GH32s and SATs reduced host proliferation, total cell area, and motility, while GH32s knockdown also reduced endosymbiont load. Duplication patterns suggest that most transfers may have occurred after the P. bursaria lineage diverged from the sampled Paramecium species but before its lineage-specific whole-genome duplication (WGD). The HTGs also showed host-associated shifts in GC content and gene length, while representative HTGs retained conserved domains and functional motifs. Together, our results support algae-to-host HGT in P. bursaria and suggest that some transferred genes may contribute to metabolic integration during endosymbiosis.

Gene Transfer, Horizontal↗
PubMed2026

Lactylation-related immune-metabolic dysregulation defines prognostic and therapeutic stratification in lung adenocarcinoma.

BACKGROUND: Lactylation links lactate metabolism with inflammatory signaling and immune regulation in tumors. However, its cellular distribution and translational value in lung adenocarcinoma (LUAD) remain unclear. METHODS: Single-cell RNA-sequencing datasets GSE189357 and GSE171145 were integrated to characterize lactylation-related activity, intercellular communication, and malignant epithelial cell states in LUAD. Single-cell-derived lactylation-related differentially expressed genes were mapped to TCGA-LUAD and multiple GEO cohorts. Univariate Cox regression and machine learning algorithms were used to construct a lactylation-related prognostic signature (LRPS). The associations of LRPS with prognosis, immunotherapy response, drug sensitivity, genomic alterations, immune infiltration, and inflammation- and metabolism-related pathways were evaluated. KRT7 was further validated using virtual knockout analysis, spatial transcriptomics, and in vitro and in vivo experiments. RESULTS: lactylation-related transcriptional activity showed heterogeneous distribution across LUAD cell populations and was associated with altered cell-cell communication. In malignant epithelial cells, LRTS-high and LRTS-low states exhibited distinct metabolic, inflammatory, and tumor-related pathway activities. LRPS showed stable prognostic performance in TCGA-LUAD and multiple GEO cohorts and remained an independent prognostic factor. Low LRPS was associated with greater potential benefit from immunotherapy, whereas different LRPS groups displayed distinct drug sensitivity, genomic alteration, and immune microenvironment patterns. KRT7 was highly expressed in LUAD and associated with poor prognosis. KRT7 knockdown suppressed LUAD cell proliferation, migration, invasion, colony formation, and tumor growth in vivo. CONCLUSIONS: This study identifies lactylation-related immune-metabolic dysregulation as a clinically relevant feature of LUAD and develops a single-cell-guided LRPS for prognosis and therapeutic stratification. KRT7 emerged as an LRPS-related functional candidate with experimentally supported roles in malignant LUAD phenotypes.

Immunotherapy↗
PubMed2026

Characteristics and functions of a cell adhesion molecule PvCadN in Penaeus vannamei during WSSV infection.

Cell adhesion not only maintains the integrity of the organism, but also plays an important role in the immune system, which is involved in modulation in the interaction between host and virus. In this study, a novel cell adhesion molecule from Penaeus vannamei, designated as PvCadN, was investigated. It had the typical molecular characteristics of cadherin family, with multiple extracellular cadherin repeat domains, a transmembrane region, and a conserved β-catenin-binding motif. Pvcadn is expressed ubiquitously across all detected tissues, with the highest transcriptional level in gills. RNA interference-mediated silencing of pvcadn significantly impaired the adhesion ability of shrimp hemocytes. Upon WSSV infection, pvcadn showed a tissue-specific expression pattern, with upregulation in gills and downregulation in hemocytes. Knockdown of pvcadn markedly suppressed the transcription of WSSV immediate-early gene ie1 and replication of the viral genome in vivo, suggesting that PvCadN acted as a potential virus-associated molecule. Furthermore, it was found that PvCadN was regulated by Lvβ-catenin, a core molecule in the Wnt signaling pathway that functions in innate immunity, at the transcriptional and protein levels. Silencing of lvβ-catenin significantly downregulated pvcadn transcription, and Lvβ-catenin bound directly to the Cadherin C domain of PvCadN. In summary, the study revealed that PvCadN was a key cell adhesion molecule involved in WSSV infection, which was regulated by Lvβ-catenin. Our findings will provide fundamental data for further investigation into cadherin-mediated immune regulation in shrimp, and offer new insights for the prevention and control of WSSV.

Animals↗
PubMed2026

The Role of Small Segmental Duplications in Generating Identical Isoforms Through Alternative Splicing Sites.

Alternative splicing plays a crucial role in expanding proteomic diversity but can also generate identical isoforms under certain conditions. While mutually exclusive splicing of tandem exons has occasionally been reported to produce identical isoforms, the extent to which other splicing events contribute to this phenomenon remains unclear. In this study, we demonstrate that alternative 5' and 3' splice site selection can also lead to the formation of identical isoforms, providing an additional type of splicing event for functional redundancy in transcriptomes. To address this, we analyzed reference genome annotations from 15 plant species, including Arabidopsis thaliana and wheat (Triticum aestivum), obtained from the RefSeq database. Identical isoforms were computationally defined as transcripts with distinct exon-intron structures but identical coding sequences. Our analysis reveals that the majority of alternative 5' and 3' fragments originate from small segmental duplications, suggesting that sequence repetition within gene regions facilitates the emergence of such splicing patterns. We also observed differences in the annotated 5' UTRs of some identical isoforms. However, since the alternative splicing sites themselves were not located within UTRs, these differences may reflect annotation uncertainty rather than genuine AS-derived variation. Given that UTR predictions in reference databases are not always precise, such observations should be interpreted cautiously. Expression analysis using an isoform-specific k-mer approach confirmed that identical isoforms can be differentially regulated. These findings suggest that, beyond expanding protein diversity, alternative splicing can also generate redundant isoforms that are differentially expressed at the RNA level, indicating potential regulatory roles. By elucidating the structural and regulatory factors contributing to the formation and retention of identical isoforms, our study provides new insights into the evolutionary and functional significance of alternative splicing in plants.

Alternative Splicing↗
PubMed2026

Simultaneously PYCR-1 and ALH-6 inhibition exacerbates 6-PPD quinone toxicity via disrupting proline and glutamate metabolisms and activating insulin signals in Caenorhabditis elegans.

Glutamate synthesized from the proline can serve as a precursor for key intermediate metabolites of citric acid cycle. Recently, we observed reduced glutamate content and expression of alh-6 controlling glutamate synthesis by 6-PPD quinone (6-PPDQ) in Caenorhabditis elegans. However, possible effect of 6-PPDQ on proline synthesis and the association with 6-PPDQ toxicity induction remain unclear. After 0.1-10 μg/L 6-PPDQ exposure, proline content was further reduced, and expression of pycr-1 governing proline biosynthesis was decreased. In 6-PPDQ exposed nematodes, RNA interference (RNAi) of pycr-1 decreased α-ketoglutarate content, enhanced mitochondrial dysfunction, reduced nicotinamide adenine dinucleotide (NADH) and reduced flavine adenine dinucleotide (FADH₂) contents, inhibited mitochondrial complex I/II activities, and decreased expressions of gas-1 and mev-1. Moreover, compared to single RNAi, double RNAi of pycr-1 and alh-6 exacerbated the 6-PPDQ toxicity in reducing α-ketoglutarate, NADH, and FADH₂ contents, and suppressing mitochondrial complex I/II activities and gas-1 and mev-1 expressions. Additionally, double RNAi of pycr-1 and alh-6 intensified toxicity of 6-PPDQ on longevity and caused upregulation of insulin ligand and receptor genes and downregulation of daf-16 and its targeted genes in 6-PPDQ exposed nematodes. Furthermore, after 6-PPDQ exposure, daf-16 RNAi suppressed pycr-1 and alh-6 expressions, suggesting formation of a regulatory feedback loop between pycr-1/alh-6 and daf-16. Our findings highlight involvement of disrupted proline and glutamate metabolisms in 6-PPDQ-induced mitochondrial dysfunction and reduced longevity.

Animals↗
PubMed2026

Reduced FOXP3 expression and its association with genetic ancestry in neuromyelitis Optica spectrum disorder: a Colombian cohort.

BACKGROUND: Autoimmune disorders are characterized by impaired immune tolerance, largely mediated by CD4⁺ regulatory T cells (Tregs), whose function depends on the transcription factor FOXP3. OBJECTIVES: To compare FOXP3 expression levels between patients with neuromyelitis optica spectrum disorder (NMOSD) and healthy controls from Bogotá, Colombia, and to explore their association with genetic ancestry. METHODS: FOXP3 expression was quantified from peripheral blood mononuclear cells using RNA-based analysis. Genomic ancestry proportions were estimated using ancestry-informative markers. RESULTS: FOXP3 mRNA expression was significantly reduced in NMOSD patients compared with controls (∼2.4-fold decrease in median expression; p = 0.027). Lower FOXP3 mRNA expression was associated with optic neuritis (p = 0.0059), but not with historical or current AQP4-IgG seropositivity. In a sensitivity analysis restricted to patients with documented historical AQP4-IgG seropositivity, the direction of reduced FOXP3 mRNA expression was preserved but did not reach statistical significance. In pre-specified exploratory ancestry-related analyses, African (p = 0.035) and Amerindian ancestry (p = 0.012) were associated with FOXP3 mRNA expression levels. CONCLUSIONS: Reduced FOXP3 mRNA expression in Peripheral Blood Mononuclear Cells (PBMCs) suggests an altered immune regulatory profile in NMOSD, potentially involving mechanisms beyond antibody-mediated immunity. The association between genetic ancestry and FOXP3 mRNA expression suggests that population-specific genetic background may influence immune regulatory pathways. These findings should be interpreted as exploratory and require validation in larger, clinically homogeneous cohorts.

Adolescent↗
PubMed2026

A novel peptide encoded by circTLL1 drives osimertinib resistance in lung cancer by modulating the NT5C2/Ras/PI3K axis.

BACKGROUND: Acquired resistance to osimertinib, a third-generation EGFR tyrosine kinase inhibitor, remains a major clinical challenge in the treatment of non-small cell lung cancer (NSCLC). Although circular RNAs (circRNAs) have been increasingly implicated in drug resistance, most studies have focused on their canonical role as microRNA sponges, while their capacity to encode functional micropeptides remains largely unexplored. This study aimed to identify novel circRNAs involved in osimertinib resistance and to characterize their regulatory functions at the protein level. METHODS: Osimertinib-resistant (OR) NSCLC cell lines were established and validated. High-throughput RNA sequencing was performed to compare the circRNA expression profiles between parental and OR cells. The function of the candidate circRNA was assessed through a series of in vitro and in vivo experiments, including cell viability assays, apoptosis analysis, and xenograft mouse models. Mechanistic investigations involved mass spectrometry, co-immunoprecipitation and western blotting to explore its protein-coding potential and downstream signaling pathways. RESULTS: We identified a novel circRNA, termed circTLL1, that was stably and significantly upregulated in OR-NSCLC cells. Functionally, overexpression of circTLL1 promoted osimertinib resistance, whereas its knockdown restored drug sensitivity both in vitro and in vivo. Mechanistically, we discovered that circTLL1 harbors an open reading frame (ORF) that is translated into a novel 90-amino-acid protein, which we designated circTLL1-90aa. Further investigation revealed that circTLL1-90aa directly interacts with and promotes the degradation of 5'-nucleotidase, cytosolic II (NT5C2), thereby uncoupling nucleotide metabolism from its normal regulatory constraints. The consequent downregulation of NT5C2 leads to elevated GTP levels and leading to the sustained activation of the downstream Ras/PI3K/AKT signaling pathway. CONCLUSION: Our findings unveil a previously unrecognized circRNA/micropeptide/metabolism cascade underlying osimertinib resistance. The identification of the circTLL1-90aa/NT5C2/Ras/PI3K axis not only expands the functional repertoire of the non-coding genome but also provides new insights into the complexity of drug resistance. Given its selective upregulation in resistant cells, circTLL1-90aa holds promise both as a predictive biomarker for treatment stratification and as an actionable therapeutic target, offering a novel strategy to overcome osimertinib resistance in NSCLC patients.

Pyrimidines↗
PubMed2026

Whole genome sequencing of unusual Hepatitis C virus subtypes and drug resistance analysis during direct-acting antiviral therapy in India.

INTRODUCTION AND OBJECTIVES: Pangenotypic direct-acting antivirals (DAA) are effective against highly prevalent Hepatitis C virus (HCV) subtypes, but have been clinically validated almost exclusively in high-income countries. Unusual HCV subtypes may carry natural polymorphisms, potentially impacting DAA susceptibility. We conducted full-genome characterization and resistance analysis of unusual HCV subtypes in patients receiving DAA treatment. PATIENTS AND METHODS: In this prospective hospital-based study, eligible patients were screened for anti-HCV antibodies and active infection was confirmed by diagnostic 5'NCR-based HCV RNA detection. Genotyping was performed by core region sequencing, and viral load quantified by real-time PCR. For whole genome sequencing, multiplex primers were designed using alignments of global reference sequences. Sequencing was carried out using the Oxford Nanopore Technology platform. Phylogenetic analysis used multiple sequence alignment and the HCV-GLUE resource for resistance-associated substitution (RAS) analysis. RESULTS: Predominant genotype was genotype 3 in 64.3% (n = 45); genotype 6 in 21.4% (n = 15); and genotype 1 in 14.2% (n = 10). Unusual HCV subtype 6xa was detected in two patients and showed no NS5A resistance mutations. One genotype 3b patient relapsed at 24 weeks post-DAA treatment completion and carried NS5A resistance-associated substitutions 30 K and 31 M both at baseline and at relapse, conferring high-level resistance to NS5A inhibitors. CONCLUSION: This is the first report from India of whole genome sequencing of HCV subtype 6xa. The identification of NS5A resistance mutations in the 3b relapse case underscores challenges for global HCV elimination strategies.

Humans↗
PubMed2026

Lower androgen sulfate metabolites in women with hypermobile Ehlers-Danlos syndrome may be associated with changed metabolism and disposition.

Hypermobile Ehlers-Danlos Syndrome (hEDS), characterized by joint hypermobility and multisystem involvement, is the most common type of EDS. Its comorbidities are wide-ranging, reflecting the involvement of connective tissue and its role in a multitude of processes. hEDS has been hypothesized to have hormonal aspects since the disorder is diagnosed more often in women and symptom changes closely correlate with hormonal shifts. To better understand the etiology and biochemical changes in hEDS and its comorbidities, a multiple-omics study was performed in women, controls (n = 45) and those with hEDS (n = 45), alongside the collection of questionnaires related to symptom severity. Metabolomic evaluation was performed on serum samples and RNA isolated from fibroblasts cultured from skin punches was analyzed for transcriptomics. Samples from hEDS patients had statistically significantly lower levels of multiple androgen sulfate metabolites, compared with controls, driven largely by participants aged 30-49. Changes to other classes of steroid hormones (corticosteroids, progestogens, and estrogens) were largely not significant between hEDS and control groups. Transcriptomics of skin fibroblasts from hEDS patients revealed downregulation of multiple enzymes involved in biosynthesis, metabolism, and disposition of androgens, compared with controls. Multiple steroid hormones correlated with symptoms surveyed in 18-29 year old participants with hEDS. Shifts in steroid hormone metabolites in hEDS compared with controls may be due to changes to metabolism and disposition, but more validation is necessary to be conclusive. This data provides insights into the unclear links between steroid hormones and hEDS and its comorbidities.

Humans↗
PubMed2026

Molecular characterization of 16 MAPK genes in silver carp (Hypophthalmichthys molitrix) and the differences of their mRNA expression between Qiandao Lake and Taihu Lake.

Mitogen-activated protein kinase (MAPK), a serine-threonine protein kinase, is involved in a variety of stress-induced responses and also plays an important regulatory role in cell metabolism. In the study the open reading frames (ORFs) of 16 MAPK genes in silver carp (Hypophthalmichthys molitrix) were obtained and verified, with the evaluations of their taxonomy, structures, conserved motifs, and evolutionary linkages. And the expression patterns of these genes in the silver carp from Qiandao Lake and Taihu Lake were explored for better understanding the response of MAPK genes to different water environment. MAPK genes of silver carp were divided into three subfamilies, including extracellular signal-regulated kinase (ERK) subfamily, p38 subfamily and C-Jun N-terminal kinase (JNK) subfamily. All these genes possessed similar structures and conserved motifs of MAPK family. Realtime qPCR revealed that the expression patterns of 10 MAPK genes (ScMAPK1, ScMAPK3, ScMAPK4, ScMAPK7, ScMAPK15, ScMAPK8a, ScMAPK8b, ScMAPK9, ScMAPK10 and ScMAPK11) in head kidney, spleen and gill of silver carp in Taihu Lake and Qiandao Lake were different. These findings provide a basis for further research on the function of MAPK in silver carp.

Animals↗
PubMed2026

In Situ Hybridization and RT-PCR Detection of Nervous Necrosis Virus in Fourfinger Threadfin, Eleutheronema tetradactylum, in Taiwan.

Between April and July 2020, suspected outbreaks of nervous necrosis virus (NNV) infection were observed in fourfinger threadfin (Eleutheronema tetradactylum) fingerling hatcheries in Pingtung County, southern Taiwan. Affected fish exhibited spiral swimming behaviour and abdominal distension, resulting in mortality rates between 50% and 100%. Histopathological examination showed severe vacuolation in the brain and ocular tissues, with large oval and/or irregular basophilic cytoplasmic inclusion bodies in the brain. Phylogenetic analysis of the viral replicase (RNA1) and capsid protein (RNA2) genes revealed high nucleotide sequence identities among the isolates in this study, with sequence similarity rates of 96.9%-99% for RNA1 and 98.2%-99.0% for RNA2 compared to RGNNV reference strains available in the NCBI GenBank database. This is the first detection of betanodavirus in fourfinger threadfin in Taiwan, using RT-PCR and ISH. A positive correlation between elevated water temperatures and disease severity indicates the need for year-round surveillance and genomic analysis to clarify the epidemiology of FTNNV. The data suggest that infected eggs may facilitate the vertical transmission of Betanodavirus. Crucially, utilising virus-free broodstock, alongside routine health screening and environmental control, is essential for mitigating NNV risks in fourfinger threadfin aquaculture.

Animals↗
PubMed2026

METTL14-mediated m6A modification of CCNE1 accelerates progression of myelodysplastic syndromes via MAPK-ERK and PI3K-AKT signaling pathways.

BACKGROUND: N6-methyladenosine (m6A) is the most common RNA modification and plays a key role in the initiation, progression, and relapse of multiple cancers, including hematologic malignancies. However, the role of m6A and m6A regulatory genes in myelodysplastic syndromes (MDS) remains unclear. This study aims to elucidate the function and molecular mechanism of methyltransferase METTL14 in MDS. METHODS: RT-qPCR was used to assess the expression of multiple m6A regulators, focusing on METTL14 in MDS patients and cell lines. METTL14 overexpressing and knockdown cell lines were established, and CCK-8, EdU, and flow cytometry assays were performed to explore the biological functions of METTL14.Dot blot, MeRIP-Seq, MeRIP-qPCR, RT-qPCR, and Western blot were employed to investigate the underlying molecular mechanism. RESULTS: Dysregulation of multiple m6A regulators was observed in MDS, among which METTL14 was upregulated. Elevated METTL14 expression increases MDS risk and adverse prognosis, emerging as a biomarker for poor prognosis. METTL14 promoted proliferation and cell-cycle progression of MDS cells while inhibiting apoptosis; corresponding changes were observed in cell cycle and apoptosis markers. METTL14 regulated cellular m6A levels. Downstream targets of METTL14 were enriched in cell cycle-related pathways, with CCNE1 identified as a critical target. Knockdown of METTL14, actinomycin D, or S-adenosylhomocysteine treatment reduced CCNE1 mRNA and protein levels. Furthermore, METTL14 activated MAPK-ERK and PI3K-AKT signaling via CCNE1 in an m6A-dependent manner, thereby promoting proliferative MDS cells' capacity. CONCLUSIONS: This study delineates a METTL14/m6A/CCNE1 signaling axis in MDS progression and suggests that METTL14-mediated m6A modification may be a potential therapeutic target for MDS.

Humans↗
PubMed2026

Comparative transcriptomic analysis of the gills and hepatopancreas of freshwater-cultured Litopenaeus vannamei under chronic nitrite stress.

To investigate the differences in molecular responses between the gills and hepatopancreas of freshwater-cultured Litopenaeus vannamei under chronic nitrite stress, a 30-day chronic stress experiment was conducted with a control group and a stress group. Transcriptomic analysis of the gills and hepatopancreas was performed using Illumina sequencing; differentially expressed genes (DEGs) were identified, and GO, KEGG, GSEA, PPI, and RT-qPCR validation were carried out. The results showed that 196 DEGs (161 up-regulated and 35 down-regulated) were identified in the gills, and 287 DEGs (199 up-regulated and 88 down-regulated) in the hepatopancreas, with only 18 DEGs shared between the two tissues. DEGs in the gills were enriched in oxidoreductase activity, glycerophospholipid metabolism, and tyrosine metabolism; DEGs in the hepatopancreas were enriched in lipid transporter activity, phagosome, ECM-receptor interaction, and riboflavin metabolism. GSEA revealed significant suppression of the mTOR pathway in the gills and the Polycomb complex pathway in the hepatopancreas. PPI network analysis identified hub genes P5CS and eEF2 in the gills, and PER, TUBB1, SHMT, and TUBB4B in the hepatopancreas. RT-qPCR validation was consistent with the RNA-seq results (R2 = 0.764). This study indicates that, under chronic nitrite stress, the gill response is centered on redox regulation and inhibition of growth metabolism, whereas the hepatopancreas response primarily involves lipid transport, cytoskeletal remodeling, and phagosome activation. The two tissues synergistically adapt through fundamental biosynthetic and motor protein pathways. This research provides molecular evidence for deciphering the nitrite tolerance mechanisms in freshwater-cultured shrimp.

Animals↗
PubMed2026

Differential contributions of mt-Tr and Cs variants to developmental cochlear defects and mitochondrial dysfunction in A/J mice.

A/J mice exhibit early-onset hearing loss linked to Cdh23, mitochondrial tRNA-Arg (mt-Tr), and citrate synthase (Cs) variants. Although developmental cochlear defects have been identified in juvenile A/J mice, the hierarchical contributions of mt-Tr versus Cs remain unclear. Using reciprocal intercross-derived strains to decouple mitochondrial haplotypes from nuclear factors, we demonstrate that the mitochondrial background is the primary determinant of auditory dysfunction. Mice with A/J mtDNA (AXB strains) displayed significantly higher ABR thresholds, accelerated hair cell attrition, and severe stereocilia dysmorphology compared to those with B6 mtDNA (BXA strains), occurring largely independently of the Cs genotype. While the Cs mutation exacerbated hearing loss, its impact was secondary to that of the dominant mitochondrial background. Systemic behavioral assessments and mitochondrial assays confirmed that A/J mitochondria exert a more profound metabolic impact than the Cs mutation. Our findings establish that the mitochondrial genomic background, with the mt-Tr locus as a prominent candidate variant, serves as the principal driver of developmental cochlear defects and early-onset hearing loss in A/J mice, while the nuclear Cs mutation acts as a synergistic modifier. This study underscores the critical role of mitonuclear crosstalk in inner ear maturation and provides new insights into the etiology of hereditary hearing loss.

Animals↗
PubMed2026

Identification of molecular subtypes in clear cell renal cell carcinoma based on chromatin regulators and tumor immune microenvironment profiling.

In the histological classification of renal cell carcinoma, clear cell renal cell carcinoma (ccRCC) accounts for the highest proportion and is the most common subtype. Despite advances in management, it continues to be associated with considerable incidence and mortality. Although surgery and systemic therapies are available, their efficacy is constrained by pronounced intratumoral heterogeneity and treatment resistance. Identifying robust biomarkers and clarifying the underlying biological mechanisms are therefore essential to improving diagnosis, risk stratification and therapeutic decision-making. In this work, we identified two ccRCC molecular subtypes displaying divergent chromatin regulator (CR) profiles and different clinical prognoses. Using the genes differentially expressed between these subgroups, we constructed a CR-related score (CRS) that effectively stratified patients according to survival. More analysis concluded that the low expression of CR was more linked with the immune-activated tumors, which encompassed the immune pathway enrichment, as well as the elevation of numerous immune cell subtypes. Moreover, elevated CRS was associated with improved immunotherapy responsiveness. Drug-sensitivity analyses nominated several candidate agents, and SMARCD3 knockdown in 786-O cells inhibited proliferation and migration and reduced sensitivity to masitinib. Collectively, these findings support the prognostic and therapeutic relevance of CR-related states in ccRCC and provide a framework for future experimental validation of chromatin-regulated tumor-immune interactions.

Humans↗
PubMed2026

Molecular Determinants and Therapeutic Targeting of Stop Codon Readthrough in Eukaryotic Translation.

Accurate translation termination is essential for proteome integrity and in eukaryotes is primarily governed by the release factors eRF1 and eRF3, which ensure precise recognition of stop codons and efficient release of nascent polypeptides. However, proteome integrity is challenged by mutations that generate premature termination codons (PTCs), leading to truncated, nonfunctional proteins and degradation of the aberrant transcript via nonsense-mediated mRNA decay (NMD). Collectively, these events account for ∼1800 human genetic diseases. Translational readthrough, the process by which near-cognate tRNAs decode stop codons and allow ribosomes to continue elongation beyond the stop codon, represents a possibility to suppress PTCs and restore full-length protein synthesis. Initially discovered in viruses as a mechanism to expand coding capacity, readthrough is now recognized as a regulated feature of eukaryotic gene expression influenced by both cis-acting sequence elements and trans-acting factors. Recent evidence highlights the remarkable context dependence of readthrough, revealing variation across transcripts, tissues, and developmental stages. In this review, we examine the molecular determinants that define stop codon recognition and readthrough efficiency, with particular emphasis on nucleotide context. We further discuss the mechanisms and binding sites of small molecules that promote PTC readthrough, and summarize the clinical development landscape of readthrough-inducing compounds for the treatment of diseases caused by nonsense mutations.

Humans↗
PubMed2026

Evaluation of one-step amplicon-based targeted enrichment for SARS-CoV-2 whole-genome sequencing using the Midnight amplicon scheme.

Genomic surveillance proved invaluable during the COVID-19 pandemic for tracking SARS-CoV-2 variants and guiding outbreak responses, underscoring the ongoing need to reduce whole-genome sequencing (WGS) costs and improve workflow efficiency to ensure accessibility in resource limited settings. Here, we evaluated a one-step reverse transcription polymerase chain reaction (RT-PCR) approach using the Midnight V2 primer scheme for targeted amplification of the SARS-CoV-2 genome, assessed its compatibility with Illumina sequencing, and compared its performance to a well-established two-step method. Initially, we determined optimal RT-PCR reaction conditions using the Midnight V2 primer panel for the one-step RT-PCR kit and scaled reaction volumes for both RT-PCR and library preparation. Clinical specimens (n = 53) that had undergone routine WGS for surveillance purposes using the established two-step RT-PCR method were compared using the one-step RT-PCR assay. For samples with genome completeness greater than 70%, both methods gave comparable results with similar sequence coverage and 100% concordance for lineage assignment. Further investigation revealed a higher percentage of reads aligning to the SARS-CoV-2 genome with a greater depth of coverage using the one-step method compared to the two-step method. Finally, analysis of scaled one-step and library reaction volumes revealed significant cost savings for samples undergoing WGS. Overall, the results presented here verify the accuracy and reproducibility of one-step targeted amplification and offer an efficient and cost-effective workflow for routine SARS-CoV-2 genomic surveillance.

Humans↗