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RNA Biology

Informa UK Limited

Preprints posted in the last 7 days, ranked by how well they match RNA Biology's content profile, based on 78 papers previously published here. The average preprint has a 0.06% match score for this journal, so anything above that is already an above-average fit.

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BRIX1 Promotes Hepatocellular Carcinoma Progression via the MAPK/ERK Pathway and Serves as a Prognostic Biomarker

Pan, X.; Wang, x.; Zhou, Y.

2026-08-31 cancer biology 10.64898/2026.08.26.747409 medRxiv
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Hepatocellular carcinoma (HCC) is particularly aggressive and difficult to treat. Due to the lack of early clinical diagnosis and the unsatisfactory clinical treatment effect, it is particularly important to identify novel markers that can predict tumor behavior in HCC. biogenesis of ribosomes BRX1 (BRIX1) is abundant in various tissues of the human body. However, the regulatory mechanisms and its role in various tissues are not fully understood. Here, we analyzed the expression pattern of BRIX1 in HCC from public gene expression databases and tissue samples from clinical HCC. We confirmed that BRIX1 was upregulated in both HCC cell lines and HCC paraffin section samples. BRIX1 depletion significantly dicreased the capacity of cells to grow and migrate in vitro, and knockdown BRIX1 suppressed tumor growth in xenograft tumor model. Mechanistically, BRIX1 depletion suppressed the MAPK/ERK pathway, as reflected by reduced phosphorylated ERK (p-ERK) levels. In summary, we provide a rational clue for the further investigation of BRIX1 as an invaluable biological marker for diagnosing and predicting prognosis of patients with HCC.

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Convergent Innate Immune and Metabolic Signatures in Parkinson's Disease and Viral Infection

Belyea, M. M.; Shafiq, M.; Lass, J.; Much, C.; Liu, Z.; Kruse, N.; Haendler, K.; Sreenivasan, V.; Gelpi, E.; Siebels, B.; Ondruschka, B.; Spielmann, M.; Klein, C.; Trinh, J.; Glatzel, M.

2026-09-01 pathology 10.64898/2026.08.28.26361092 medRxiv
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Viral infections have long been proposed as environmental contributors to neurodegenerative diseases, including Parkinson's disease (PD), yet the molecular mechanisms linking infection and neurodegeneration are not well defined. Neuroinflammation and disruption of central nervous system (CNS) homeostasis have emerged as potential mediators. In this study, we used severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, as a model pathogen to investigate convergent molecular pathways between viral infection and PD. Single-nucleus RNA sequencing (snRNA-seq) was performed on post-mortem striatal tissue from 14 individuals stratified into four groups: COVID-19 only (COVID-19), PD only (PD), comorbid PD with COVID-19 (PD/COVID-19), and controls (Control). The PD/COVID-19 group exhibited an expanded astrocytic population and a pronounced interferon-associated molecular signature characterized by increased expression of canonical interferon-stimulated genes, including IFI44L (average log2FC= 3.9; adjusted p=2.3 x 10-373), IFI44 (average log2FC=2.9; adjusted p=8.0 x 10-266), ISG15 (average log2FC=3.1; adjusted p=1.2 x 10-197), and RSAD2 (average log2FC= 3.5; adjusted p=8.6 x 10-111). Pathway analyses demonstrated activation of innate immune and antiviral signaling pathways, particularly within microglia and astrocytes, including interferon signaling, pattern-recognition receptor pathways, and complement-associated responses. In parallel, genes involved in lipid metabolism, cholesterol homeostasis, synaptic maintenance, and neuronal signaling were reduced across disease groups. Proteomic analyses independently confirmed enrichment of antiviral and interferon-associated pathways and identified convergent suppression of sterol, cholesterol, and lipid metabolic processes. Our findings identify a convergent molecular signature linking PD and COVID-19, pronounced in comorbid individuals and characterized by interferon-driven innate immune activation, glial inflammatory responses, and dysregulation of lipid metabolic homeostasis. Collectively, the data support a model in which severe viral infection amplifies biological pathways already implicated in PD pathogenesis.

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Eucalyptus microRNA Archive (EMA): a multi-study and cross-condition curated database of microRNAs in Eucalyptus grandis

Aires Teixeira, J. V.; Motta Venancio, T.; Quintanilha-Peixoto, G.; Pimenta de Oliveira, K. K.

2026-08-31 plant biology 10.64898/2026.08.29.747619 medRxiv
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MicroRNAs (miRNAs) are key post-transcriptional regulators of development, stress response, and secondary cell wall formation in woody plants, yet annotations for Eucalyptus grandis, the world's most widely planted hardwood, remain fragmented across studies using incompatible discovery pipelines and filtering criteria. Here we present the Eucalyptus MicroRNA Archive (EMA), a curated, locus-resolved database integrating three independent small RNA sequencing datasets spanning vegetative tissue, somatic embryogenesis, and mechanically induced tension wood formation. Applying annotation criteria aligned with current plant miRNA standards, EMA catalogs 99 curated miRNAs (31 previously described, 68 novel) organized into 34 family-level groupings under a three-tier confidence system, known-reference-supported, multi-study replicated, or single-study, that preserves study-of-origin and sample-level evidence for every entry. Cross-study comparison showed that only 9 of 99 entries (9.1%) were independently supported by all three datasets, supporting an evidence-tiered rather than binary annotation scheme. Target prediction against the E. grandis transcriptome yielded 1,773 miRNA-target interactions spanning 764 loci, integrated into a combined miRNA-target and protein-protein interaction network. This network resolved into functionally coherent, mutually isolated clusters, including an miR482-associated NBS-LRR/TIR disease-resistance hub with a substantial translational-repression component, alongside modules enriched for ribosome biogenesis and translation, DNA replication, and nitrogen and carbohydrate metabolism. EMA is publicly accessible through an interactive web dashboard, with all curated data, source code, and analysis scripts openly available, providing a reproducible, extensible framework for E. grandis miRNA research and a template for similarly structured resources in other non-model woody species.

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m1A58 acts as a conformational checkpoint coupling human initiator tRNA maturation to translation initiation

Liu, R.-J.; Li, H.; Wu, X.-Y.; Zhou, Y.-J.; Yared, M.-J.; Wang, C.-X.; Tian, P.-Y.; Liu, Q.-Y.; Bao, Z.-G.; Barraud, P.

2026-09-01 molecular biology 10.64898/2026.08.28.747798 medRxiv
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tRNAs are characterized by extensive chemical modifications that influence tRNA fate. N1-methyladenosine at position 58 (m1A58) is a widespread core tRNA modification linked to physiological and pathological processes. However, how m1A58 coordinate tRNA folding and processing to ensure translational efficiency in mammalian cells remains largely unknown. Using acute dTAG-mediated degradation and CRISPR-Cas9 knockout, we identified initiator methionine tRNA (tRNAiMet) as selectively vulnerable to m1A58 loss, lacking the isodecoder buffering observed for most other tRNA isoacceptors. NMR analysis of the tRNAiMet showed that m1A58 stabilizes D/T-loop interactions, consistent with a maturation-competent conformation. In vitro processing assays further demonstrated that m1A58 promotes RNase P-mediated 5'-leader removal and RNase Z-mediated 3'-trailer cleavage, while La/SSB protects accumulated precursors. Disrupting this checkpoint impaired the assembly of the eIF2-containing 43S pre-initiation complex and global protein synthesis, which was substantially rescued by adding m1A58-modified tRNAiMet. Acute TRMT6 degradation elicited temporally coordinated gene-expression responses involving proteostasis, transport and signaling. Together, these findings establish m1A58 as a conformational checkpoint coupling human initiator-tRNA maturation to translation initiation and stress responses.

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The splicing kinase PRPF-4 is required for somatic development and germline function in C. elegans

Barron, W. C.; Wei, X.; Ferdousy, S.; Zhu, L.; Meng, F. W.; Chen, B.

2026-08-31 molecular biology 10.64898/2026.08.28.747746 medRxiv
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Pre-mRNA splicing is essential for gene expression, yet how disruption of core spliceosomal factors produces tissue- and developmental stage-specific phenotypes remains poorly understood. Here, we investigated the in vivo function of the conserved spliceosomal kinase PRPF-4 in C. elegans using endogenous reporter analysis, conditional protein depletion, and transcriptome-wide analysis of alternative splicing and gene expression. We found that PRPF-4 is broadly expressed throughout development and is continuously required for postembryonic development, with distinct requirements in the pharynx, nervous system, and germline. Acute PRPF-4 depletion rapidly disrupts alternative splicing across thousands of transcripts, with exon skipping representing the predominant class of affected events. In addition, PRPF-4 depletion results in a robust transcriptome shift with induction of components of the spliceosome and repression of ciliary and ion transport-related transcripts. These findings establish PRPF-4 as a central regulator of RNA metabolism and demonstrate the far-reaching effects on gene expression caused by loss of core spliceosomal components.

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Maternal cell-free RNA versus combined screening for first-trimester prediction of early-onset preeclampsia: a nested case-control study

Satorres-Perez, E.; Castillo-Marco, N.; Igual, M.; Cordero, T.; Munoz-Blat, I.; Monfort-Ortiz, R.; Marcos-Puig, B.; Simon, C.; Garrido-Gomez, T.; Perales-Marin, A.

2026-09-02 obstetrics and gynecology 10.64898/2026.08.28.26361628 medRxiv
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Background. In Europe, first-trimester combined screening with the Fetal Medicine Foundation (FMF) algorithm identifies women at increased risk of preeclampsia who may benefit from personalized aspirin prophylaxis. However, a substantial proportion of early-onset preeclampsia (EOPE) remains undetected at clinically acceptable specificity. Objective. To evaluate the first-trimester performance of MaiRa for early-onset preeclampsia (EOPE) risk stratification by benchmarking it against FMF screening in the same women, characterizing discordant patient-level classification profiles and exploring potential implementation strategies. Study Design. This secondary case-control analysis was nested within the prospective, multicentre PREMOM cohort [NCT04990141], which enrolled women with singleton pregnancies across 14 tertiary hospitals in Spain. First-trimester MaiRa and FMF risk estimates were evaluated in the same 126 pregnant women, comprising 99 uncomplicated controls and 27 EOPE cases, defined by disease onset before 34 weeks. Discrimination was compared using a stratified paired bootstrap analysis of the areas under the receiver-operating-characteristic curves. Performance was assessed at prespecified clinical thresholds, and detection rates were evaluated at fixed false-positive rates. Universal and contingent MaiRa implementation strategies were also evaluated. Results. MaiRa showed greater first-trimester discrimination for EOPE than FMF combined screening (AUC, 0.974 vs 0.900; P=.040) and consistently achieved higher detection rates across fixed false-positive rates. At false-positive rates of 5% and 10%, MaiRa detected 85.2% and 92.6% of EOPE cases, compared with 44.4% and 70.4% for FMF, respectively. Patient-level analysis demonstrated that MaiRa identified 12 of 27 EOPE cases (44.4%) classified as low risk by FMF; these pregnancies generally exhibited less abnormal conventional first-trimester profiles, including fewer maternal risk factors, lower mean arterial pressure and lower uterine artery pulsatility index, yet 8 of 12 (66.7%) subsequently developed severe EOPE. Exploratory implementation analyses showed that universal MaiRa screening achieved the highest EOPE detection, whereas a contingent strategy using FMF for triage and reflex MaiRa testing reduced molecular testing to 35.7% of pregnancies while maintaining 77.8% sensitivity and 97.0% specificity. Conclusion. MaiRa provided greater first-trimester discrimination for EOPE than conventional combined screening and detected additional pregnancies that later developed severe disease despite less abnormal conventional screening profiles. The findings suggest that maternal plasma cfRNA profiling captures biological alterations not fully reflected by combined first-trimester screening and support further prospective evaluation in an independent, unselected obstetric population. Key words: early-onset preeclampsia; first-trimester screening; cell-free RNA; liquid biopsy; Fetal Medicine Foundation algorithm; combined screening; risk stratification; aspirin prophylaxis.

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Identification of miR-615-5p/ID1 axis crucial in the pathogenesis of pancreatic ductal adenocarcinoma (PDAC)

Sarkar, A.; Ray, S.; Ray, A.; Biswas, K.

2026-08-31 cancer biology 10.64898/2026.08.27.747461 medRxiv
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Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy characterized by high metastatic dissemination, therapy resistance, and poor clinical outcome. Inhibitor of differentiation 1 or ID1, is frequently overexpressed in PDAC and is associated with tumour progression and adverse clinical outcome. However, the mechanisms governing its post-transcriptional regulation remain insufficiently characterized. Here, we identify tumour-suppressive miR-615-5p as a regulator of ID1 expression in PDAC. Integrative in-silico target prediction prioritized miR-615-5p based on seed complementarity and thermodynamic stability with the ID1 3' -UTR. Expression analysis of available PDAC clinical datasets revealed reduced miR-615-5p expression associated with increased ID1 expression. Direct association was validated using luciferase reporter assays, where miR-615-5p suppressed 3' -UTR reporter activity of ID1 in a sequence dependent manner, while mutation of the predicted binding site attenuated this effect. Further biotinylated-RIP and AGO2-RIP assays demonstrated the co-enrichment of ID1 transcripts and miR-615-5p with AGO2 associated RISC complexes, while AntimiR mediated inhibition of miR-615-5p perturbs association between miR/ID1 to AGO2, supporting interaction specificity. Functionally, modulation of miR-615-5p altered ID1 expression and impacted PDAC cell migration in vitro. Mechanistic analyses further indicated that the miR-615-5p/ID1 axis influences autophagic flux where miR-615-5p mediated inhibition of autophagy suppresses ID1 dependent cellular migration. Collectively, these findings define a previously uncharacterized miRNA-dependent regulation of ID1 expression and link this axis to autophagy-associated migratory responses in PDAC cells. The study expands the post-transcriptional regulatory landscape of ID1 and provides a possible mechanism where suppression of miR-615-5p leads to ID1 overexpression and subsequent poor clinical outcome in PDAC cells.

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Network-based meta-analysis maps stage-dependent molecular programs in MASLD through MASLD-META NETWORK application

Kumak, E.; Darde, T.; Konu, O.

2026-08-31 bioinformatics 10.64898/2026.08.26.747338 medRxiv
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Metabolic dysfunction-associated steatotic liver disease (MASLD), the leading cause of chronic liver pathologies worldwide, represents a growing clinical burden. Its diagnosis remains reliant on liver biopsy that limits early detection and the ability to capture molecular changes across disease progression. A systematic understanding of stage-dependent gene expression changes is essential to identify biomarkers and effectively characterize disease mechanisms. Therefore recent studies provided databases for searching genes as well as prediction of multi-gene signatures for disease progression. However, there is still a need for interactive and comprehensive meta-analysis of datasets of MASLD patients with available histological metadata. Herein, we performed a meta-analysis of RNA-seq datasets using NAFLD Activity Score (NAS; n = 897) and fibrosis stage (n = 856) upon conducting pairwise comparisons across histological stages and identified differentially expressed genes associated with disease progression. Most importantly, we provide our findings via a dedicated web server, the MASLD-META NETWORK (https://masld.scilicium.com), enabling users to interactively explore meta-analysis results across diverse network modalities. In addition, we characterized gene expression dynamics across increasing disease stages to identify consistent progression-associated pathways using Louvain clustering. Network-based parameters such as centrality in combination with meta-analysis scores further highlighted central genes and pathways implicated in disease mechanisms. Accordingly, MASLD-META NETWORK enabled an integrative reassessment of recently published gene signatures, identifying COL1A1, COL3A1, THBS2, FBLN5, and PDGFA as the most central genes, and SULF2, MMP14, IL32, GPNMB, and COL3A1 as candidate markers of earlier transcriptional alterations. Network analysis of MASLD associated biological modules further identified LAMA2 and LAMA3 as previously unrecognized central candidate targets.

9
Maturation-dependent splicing alterations constrain SYNGAP1 splice-switching therapy

Kamp, J. A.; Wijnant, K. A.; Maas, N.; Gülyurt, D.; Rieder, M. J.; Jolfaei, M. A.; Gontan, C.; Kushner, S. A.; Elgersma, Y.; Vissers, L. E.; Nadif Kasri, N.; De Vrij, F. M.

2026-08-31 neuroscience 10.64898/2026.08.26.745682 medRxiv
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Haploinsufficiency in SYNGAP1 causes a severe neurodevelopmental syndrome. SYNGAP1 protein is mainly detected in neuronal synapses. However, SYNGAP1 RNA is more widely expressed and strongly regulated via alternative splicing: alternative 3' splice site (A3SS) inclusion leads to non-productive transcripts that are degraded through nonsense-mediated decay. Recently, splice-switching oligonucleotides (SSOs) that redirect SYNGAP1 splicing to increase SYNGAP1 protein levels were developed. However, we hypothesized that during neuronal maturation, non-productive splicing may decrease to enhance functional transcripts in mature neurons. This would reduce the abundance of the SSO target transcript, limiting the potential for SSO treatment to increase neuronal SYNGAP1 expression. Using neural differentiation of human induced pluripotent stem cells, we show that the A3SS transcript is abundant in neural progenitors, astrocytes, microglia and immature neurons, with minimal presence in mature neurons. These data imply that SSOs targeting A3SS might lack therapeutic efficacy to rescue the neuronal phenotypes associated with SYNGAP1 haploinsufficiency.

10
Inhibition of JEV infection using β-Catenin specific inhibitor, iCRT-14

Datey, A.; Ghosh, S.; Chatterjee, S.; Bhowmick, B.; Ghatak, A.; Subudhi, B. B.; Chattopadhyay, S.

2026-08-31 molecular biology 10.64898/2026.08.29.747967 medRxiv
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The lack of effective anti-JEV therapy possesses significant challenge to control JEV. {beta}-catenin, a key mediator of Wnt signaling pathway regulates different viral replication and host immune responses. However, its role in JEV infection remains to be elucidated. Thus, the current study focused on evaluating iCRT-14, a specific {beta}-catenin inhibitor, against JEV. Treatment with iCRT-14 following JEV infection resulted efficient reduction in viral progeny release, viral RNA and protein levels in Huh7 and HEK293T cells. Further, active and total {beta}-catenin, Cyclin D-1 and GSK3-{beta}, the other key pathway players were also modulated in infected and inhibitor treated cells. Moreover, iCRT-14 showed an IC of 4.56 in Huh7 cell and maximal inhibition at the early stages of the JEV life cycle. Interestingly, the overexpression of {beta}-catenin in both the cells and siRNA-mediated {beta}-catenin knockdown (in Huh7 cells) significantly abrogated JEV replication, as evidenced by decreased viral titers, viral protein expression, and viral as well as total RNA levels. Moreover, the reduction in extracellular (84%) and intracellular (60%) viral titers following iCRT-14 treatment highlights its role in impairing JEV infection. Further, in silico molecular docking and co-immunoprecipitation studies demonstrated interactions between {beta}-catenin and the JEV NS5 and E proteins. Collectively, these findings suggest that optimum level of {beta}-catenin is required for efficient JEV infection, highlighting its potential as a target for designing host-directed control strategies to regulate viral infection.

11
The evolutionarily conserved C-terminal domain of a domesticated transposase-derived protein regulates its DNA integration ability

Saha, A.; Ghosh, A.; Majumdar, S.

2026-08-31 biochemistry 10.64898/2026.08.31.747927 medRxiv
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THAP9 is a transposable element-derived gene which encodes a protein that is homologous to the active Drosophila P-element transposase (DmTNP). Both THAP9 and DmTNP possess a C-terminal domain (CTD) which is functionally uncharacterized. Sequence and structural analysis suggest that the THAP9-CTD has a novel fold which is only found in THAP9 homologs. To explore the evolutionary history and characteristics of this novel domain, exhaustive phylogenetic analysis (using MSA, structure prediction, MSTA-based clustering) was performed. THAP9-CTD homologs were more widely distributed throughout the animal kingdom in comparison to DmTNP-CTD homologs which were restricted to arthropods. Moreover, the THAP9-CTD homologs were more conserved, especially among mammals and birds and their average length increased in a class-specific manner. Comparison with the DmTNP-CTD homologs demonstrates that although their respective CTDs may have evolved independently, they both surprisingly share similar secondary structure elements consisting of three conserved helical regions made of hydrophobic residues that are predicted to make up a conserved core. The role of the respective CTDs were further investigated by creating truncation mutants lacking the CTD. Interestingly both THAP9 and DmTNP truncation mutants are still capable of DNA excision and integration suggesting that their respective CTDs are not essential for DNA transposition. Moreover, CTD truncation favours DNA integration in THAP9: this suggests that CTD acquisition during evolution may have led to THAP9 domestication as observed in other transposable element-derived genes like Rag1 and piggybac, which have similar terminal regulatory domains.

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Pan-cancer analysis identifies nine conserved miRNA regulators of tumor cytolytic activity and clinically actionable immune targets

Bagherlou, N.; Aliyari, S.; Salehi, Z.; Pirouzkhah, M.; Weis, C.-A.

2026-08-31 cancer biology 10.64898/2026.08.30.748071 medRxiv
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Abstract Background: Cytolytic activity (CYT), a widely used transcriptomic surrogate of anti-tumor immune cytotoxicity derived from GZMA (granzyme A) and PRF1 (Perforin 1) expression, is associated with clinical outcomes across cancers. MicroRNAs (miRNAs) are key post-transcriptional regulators of tumor immunity, yet their pan-cancer roles in modulating cytolytic activity remain incompletely understood. Objective: This study aimed to identify conserved miRNA regulators of tumor cytolytic activity and their downstream gene-mediated networks across diverse cancer types, while evaluating their clinical and therapeutic relevance. Methods: Matched miRNA and mRNA expression profiles from 9,288 primary tumors across 31 TCGA cancer types were analyzed. A multi-stage framework was applied: per-cancer Spearman correlations (|{rho}| >= 0.30, FDR < 0.05) identified recurrent CYT-associated miRNAs (at least 3 cancer types); these were integrated with TargetScan-predicted targets and subjected to pan-cancer and cross-cancer triple filtering (miRNA-gene and gene-CYT associations). All associations underwent tumor purity adjustment using Consensus Purity Estimate (CPE), with LUMP (Leukocytes Unmethylation for Purity) as sensitivity analysis. Candidates were further prioritized by random forest modeling with bootstrap stability, cancer-type-adjusted Cox regression, mediation analysis, immune cell deconvolution, k-means molecular subtyping, pathway enrichment, and DGIdb-based drug-target prioritization. Results: The analysis converged on 38 high-confidence miRNA-gene-CYT regulatory triplets involving 9 conserved miRNAs and 31 target genes after stringent purity adjustment and multi-layer validation. All nine miRNAs exhibited complete bootstrap stability. Mediation analysis confirmed significant gene-level mediation in 37 of 38 triplets (FDR < 0.01), with mediated proportions up to 94%. The final miRNA signature defined two distinct pan-cancer immune subtypes (immune-hot vs. immune-cold) with significantly different cytolytic activity and overall survival (OS) (HR = 0.754, FDR = 1.12 x 10^-4). The network was enriched for T-cell activation and lymphocyte differentiation pathways and highlighted multiple druggable targets, including CTLA4 and CD274 (PD-L1), nominating 124 candidate compounds. Conclusions: In conclusion, this tumor purity-adjusted pan-cancer study defines a compact, reproducible, and clinically relevant miRNA network that regulates cytolytic activity across diverse malignancies. By linking miRNA biology to immune subtyping and actionable therapeutic targets, the present work provides a valuable foundation for advancing precision immuno-oncology.

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Acute Protein Responses Control SARS-CoV-2-specific Neurocognitive and General Post-Viral Sequelae

Liou, T. G.; Andrews, R. J.; Bass, B. L.; Battey, H.; Buonfiglio, L. G. V.; Cahill, B. C.; Cox, J. E.; Gibson, S.; Hartsell, S. C.; Hatton, N.; Hazel, M.; Helms, M. N.; Jensen, J. L.; Kartsonaki, C.; Kupfer, J.; Li, Y.; Lopes, F. B. T. P.; Manuel, A.; Marchetti, M.; Marvin, J. E.; Middleton, E. A.; Mimche, P.; Packer, K. A.; Paine, R.; Szczesniak, R. D.; Sturrock, A. B.; Tandar, A.; Tarbet, B.; Ulrich, A.; Warner, D.; Warren, K.; Weis, A. M.; Zimmerman, E.; Yoon, S.; Ownbey, M.; Youngquist, S. T.; Adler, F. R.

2026-08-31 infectious diseases 10.64898/2026.08.27.26361488 medRxiv
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Post-acute infection syndromes (PAIS) follow viral syndromes including post-acute sequelae of COVID19 (PASC) which complicates 10-25% of SARS-CoV-2 infections. These syndromes lack precise explanatory mechanisms. We studied 173 human saliva proteomes during respiratory viral syndromes, seeking associations between 44 clinically-relevant protein expression patterns and subsequent sequelae counts. Exploratory models adjusted by extensive clinical annotations found interactions between 23 acutely-responsive proteins and SARS-CoV-2 infection that inversely predicted subsequent neurocognitive sequelae. An overlapping 19 acutely-responsive proteins during any acute respiratory viral syndrome inversely predicted general fatigue-related sequelae. Altogether, 29 proteins, derived from interferon stimulated genes (ISG), were uniformly beneficial, including 13 predictive of both neurocognitive and general sequelae. The proteins suggested both shared early pathobiology and virus-specific protective responses that shaped resolution of acute disease and different PAIS. Acutely elevated protective ISG proteins associated with reduced post-viral symptoms identify investigational starting points for novel mechanisms, diagnostics and therapeutics for PASC and PAIS.

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Two methylthio-alkane reductases are functionally distinct in the purple nonsulfur bacterium Rhodopseudomonas palustris

Marquez Reyes, N. L.; Arroyo-Carriedo, A. A.; North, J. A.; Fixen, K. R.

2026-08-31 microbiology 10.64898/2026.08.20.746119 medRxiv
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Organosulfur compounds are the predominant sulfur source in terrestrial environments, requiring bacteria to use enzymes for their assimilation. Most described organosulfur-assimilating enzymes require oxygen, and enzymes that function under anoxic conditions remain poorly understood. Recently, methylthio-alkane reductase (Mar), a nitrogenase-like enzyme that reduces the volatile organic sulfur compounds (VOSCs) methylthio ethanol (MT-EtOH), dimethyl sulfide (DMS), and ethyl methyl sulfide (EMS) under anoxic conditions, was identified in the purple nonsulfur bacterium Rhodospirillum rubrum. However, another purple nonsulfur bacterium, Rhodopseudomonas palustris, has three loci of nitrogen fixation-like (NFL) genes with high sequence similarity to Mar, suggesting additional Mar-like enzymes with distinct roles. Here, we tested whether these NFL genes are required for VOSC assimilation in R. palustris. RNA-seq analysis revealed that all three NFL loci are upregulated under sulfur limitation, supporting a role in sulfur assimilation. Only disruption of the NFL genes encoded by RPA2634-37, renamed marBHDK1, caused fitness defects with EMS, DMS, and dimethylsulfoniopropionate (DMSP) as sulfur sources, indicating a functional Mar enzyme. The NFL genes RPA2347-48 and RPA2353-54, renamed marKD2 and marHB2, were required for activity with MT-EtOH or ethanethiol but not DMS, EMS, or DMSP. No activity was observed for the third locus, RPA2363-64, renamed nflDK. Overall, two Mar homologs in R. palustris are capable of VOSC reduction, one specialized for simple VOSCs and the other preferring a substrate with an additional functional group.

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The interaction between NC(p7)1-55 and p6 may regulate interactions with nucleic acids during assembly through modulation of Gag folding.

LARUE, V.; Nonin-Lecomte, S.

2026-09-01 biophysics 10.64898/2026.08.28.747767 medRxiv
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We present the solution structures of HIV-1 proteins NC(p7)1-55 corresponding to the full-length NC(p7) and mature p6. The studies were carried in water and, to mimic the membrane, in micellar DPC (Dodecylphosphocholine) conditions. Our results unravel for the first time the structure adopted by the N-terminal amino acids of the free NC(p7)1-55, with the formation of a small helix spanning residues F6 to R10. Our NMR and Fluorescence Anisotropy data disclose an interaction between NC(p7)1-55 and p6 both in water and DPC, with respective Kd of 2.5mM and 370 mM at 23{degrees}C. The interaction is thus strengthened in lipidic conditions. Protein p6 stabilizes the N-terminus of NC(p7)1-55 while increasing at the same time the dynamic of the first zinc finger. Although the entire p6 sequence is involved in the interaction, we show that its C-terminal region is particularly sensitive to the presence of NC(p7)1-55, with a propensity of forming a a helix ranging from amino acids S111 to F116. This study brings experimental evidence of a direct protein-protein interaction between p6 and the N-terminal region of NC(p7)1-55. We further show that such interaction is readily accommodated within the NC(p15) framework and hypothesize that it may facilitate the selective assembly of assembly of the viral genomic RNA (gRNA) in the cell.

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Benchmarking the Intratumoral Microbiome in Pancreatic Ductal Adenocarcinoma: A Longitudinal Assessment of Contamination Sources and Decontamination Strategies

Dang, L.; Eskelson, L.; Hamm, J.; Blumberg, J.; Wegener, U.; Beissbarth, T.; Ellenrieder, V.; Neesse, A.; Ammer-Herrmenau, C.

2026-08-31 cancer biology 10.64898/2026.08.24.746744 medRxiv
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Pancreatic ductal adenocarcinoma (PDAC) harbors a distinct intratumoral microbiome. Yet rigorous characterization of its composition is hampered by pervasive environmental and procedural contamination. Sources of contamination have not been thoroughly explored, and the methods of decontamination have not been sufficiently evaluated in a benchmarking manner. We systematically collected >300 negative control (NCT) samples comprising paraffin from formalin-fixed paraffin-embedded (FFPE) samples, lysis buffer and sterile water over a period of four years processed by different laboratory persons (LP). All samples were sequenced using full-length 16S rRNA gene sequencing with Oxford-Nanopore Technologies. We benchmarked four decontamination methods (restrictive filtering, decontam, SCRuB, and the Nejman et al.-derived (Nj) pipeline) against fresh-frozen tumor samples (FF) from LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre (KPC) mice, using the abovementioned contamination assessment to calculate a composite score for the assessment. Further, we validated those methods via technical replicates. Microbial profiles of NCT samples were significantly determined by control type, LP, year and season reflecting complex batch effects. The 15 most abundant contaminants spanned well-characterized environmental taxa and human commensals from the oral cavity. The LP processing samples left a significant microbial trace highly contributing to the batch effect. Decontamination benchmarking demonstrated that the Nj method consistently outperformed alternatives in both composite score and inter-replicate concordance. Application of Nj to fresh frozen PDAC samples substantially reduced contaminant burden while preserving putative tumor-associated signals in FF but not FFPE samples. Our results support the adoption of the Nj decontamination approach for future intratumoral microbiome studies in fresh frozen tumor samples.

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Vaginal Steaming Practices Among Women At Mulago Sti Clinic, Uganda: Prevalence, Lactobacilli Proportion Differences, And Associated Factors.

Kakai, D.; Twinamasiko, N.; Kigozi, E.; Namutale, R.; Mutesi, B. A.; Bagaya, J.; Akinyi, L.; Kajumbula, H.; Nakubulwa, S.

2026-09-01 obstetrics and gynecology 10.64898/2026.08.28.26361407 medRxiv
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Abstract Background: Vaginal steaming has gained popularity among women for reasons known best to them. However, the effects of vaginal steaming on vaginal lactobacilli levels remain poorly understood and understudied. This study investigated the prevalence, assessed differences in the presence of bacterial vaginosis (BV) among women who practiced vaginal steaming and those who do not and determined the factors associated with vaginal steaming among women attending Mulago Sexually Transmitted Infections (STI) clinic in Uganda. Methods: This study utilized a cross-sectional design to enroll 181 women aged 18 to 49 years who were systematically sampled at Mulago STI clinic. Interviews were conducted to obtain the demographic characteristics of the participants. Vaginal swabbing and Gram staining were done to attain lactobacilli counts by microscopy which were categorized using the Nugent score. Data were analyzed using Stata. The potential confounding effects of other variables on the relation between vaginal steaming and the presence of bacterial vaginosis as well as factors associated with vaginal steaming were assessed using modified Poisson regression. Results: Prevalence of vaginal steaming was 40.3%, (95% confidence interval (CI) 33.0% - 48.0%). There were 41.1% women who practiced vaginal steaming occasionally, 53.4% who used hot water having herbs and 78.1% who practiced vaginal steaming for medical reasons. There was no difference in the presence of bacterial vaginosis when women who practiced vaginal steaming were compared to those who did not (p-value = 0.286). Factors that were significantly associated with vaginal steaming included having experienced vaginal issues (aPR = 0.07, 95% CI 0.01 - 0.12, p value = < 0.001) and contraceptive use (aPR= 0.52, 95% CI 0.37 - 0.72, p value = 0.001). Conclusions: About 2 in every 5 women at Mulago STI clinic reported to have indulged in vaginal steaming. There was no difference in the presence of bacterial vaginosis when women who practiced vaginal steaming were compared to those who did not. Having experienced vaginal issues and contraceptive use were significantly associated with vaginal steaming among women at Mulago STI clinic, Uganda. The Ministry of Health of Uganda should establish targeted screening and treatment for bacterial vaginosis alongside other sexually transmitted infections.

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Plasma and follicular fluid concentrations of carotenoids, tocopherols and retinol in a French population of women undergoing in vitro fertilization: a monocentric non-interventional study

Ndiaye, A.; Thiebaut, A. C. M.; Borel, P.; Sabran, C.; Elis, S.; Guerif, F.; Maillard, V.

2026-09-01 sexual and reproductive health 10.64898/2026.08.28.26360803 medRxiv
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The distribution of fat-soluble compounds (including antioxidants) in follicular fluid (FF) remains sparsely documented in relation to in vitro fertilization (IVF) outcomes and existing studies have reported diverging associations. This study aimed to describe plasma and FF concentrations of fat-soluble micronutrients in women undergoing IVF and to analyze their adjusted associations with ovarian function, embryo development and pregnancy outcomes. In 2021-2022, plasma and FF samples were collected from 82 women (first IVF cycle) at oocyte puncture, along with lifestyle data covering the three preceding months. Eleven compounds (two tocopherols, three xanthophylls, five carotenes and retinol) were quantified. All compounds were detected in both compartments (lowest in FF) except phytoene, undetectable in FF. Plasma and FF -tocopherol concentrations were positively associated with plasma estradiol levels before oocyte puncture (both p<0.01) while FF -carotene and lycopene were inversely associated with plasma progesterone concentrations (p=0.01 and 0.02, respectively). Plasma phytofluene and phytoene were positively associated with mature oocyte rate (p=0.03 and p=0.01, respectively), while FF retinol was negatively associated (p=0.03). Carotenes, tocopherols and retinol were inversely associated with later IVF outcomes: fertilization rate (p<0.001 for plasma g-tocopherol, 0.02 for FF retinol), top-quality embryo (p=0.02 for plasma phytofluene), biochemical pregnancy at day 7 post-embryo transfer (p=0.05 for plasma -tocopherol, 0.02 for plasma -carotene), clinical pregnancy (p=0.03 for plasma -tocopherol, 0.01 for plasma phytoene) and live birth (p=0.04 for plasma -tocopherol, 0.02 for plasma phytoene). Plasma and FF g-tocopherol were positively associated with embryo fragmentation (both p<0.05). Finally, among xanthophylls, only plasma {beta}-cryptoxanthin was positively associated with plasma progesterone concentrations (p=0.02). Our findings of heterogeneous associations between tocopherols, carotenes, retinol and IVF outcomes across the stages of IVF suggest a beneficial effect limited to early outcomes and support a complex and context-dependent role of these compounds in female reproduction. This manuscript has been submitted to PlosOne on August 19, 2026.

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Risk-Adapted Atrial Fibrillation Monitoring after Embolic Stroke of Undetermined Source: A Population-Based Study

Elbischger, J.; Krainer, A.; Ruprechter, T.; Haidegger, M.; Berger, N.; Hatab, I.; Fandler-Höfler, S.; Heine, M.; Jagiello, J.; Koller, H.; Lilek, S.; Veeranki, S. P. K.; Enzinger, C.; Manninger, M.; Bisping, E.; Scherr, D.; Gattringer, T.; Kneihsl, M.

2026-08-31 neurology 10.64898/2026.08.27.26361578 medRxiv
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Background: Atrial fibrillation detected after stroke (AFDAS) is frequently diagnosed after embolic stroke of undetermined source (ESUS) and has important implications for secondary stroke prevention. Although prediction scores have been proposed to identify patients at increased risk of AFDAS, prospective evidence supporting their implementation to guide rhythm monitoring in routine clinical practice is limited. Methods: In this prospective, population-based implementation cohort study, adults with ESUS were enrolled between January 2022 and December 2024 across all stroke centers in Styria, Austria. The Graz AF Risk Score was prospectively implemented as part of a risk-adapted diagnostic pathway for cardiac rhythm monitoring. Patients with a score [&ge;]4 were recommended for implantable loop recorder monitoring, whereas monitoring in those with scores <4 remained at the treating physician's discretion. The primary outcome was AFDAS detection; recurrent ischemic stroke and recurrent stroke etiology were secondary outcomes. Results: Among 784 patients (median age 73 years [IQR 64-80], 45.7% women), AFDAS was detected in 166 patients (21.2%) during a median follow-up of 26.3 months (IQR 20-34). AFDAS detection was substantially higher in patients with a Graz AF Risk Score [&ge;]4 than <4 (38.1% vs. 3.9%; p<0.001). After adjustment for age, sex and ILR monitoring, a score [&ge;]4 independently predicted AFDAS (HR 6.3, 95% CI 3.5-11.2; p<0.001) and recurrent ischemic stroke (HR 2.2, 95% CI 1.1-4.1; p=0.023). Only one recurrent stroke in patients with a score <4 was attributable to atrial fibrillation (AF) (1/18, 5.6%). Conclusions: Prospective implementation of the Graz AF Risk Score identified patients with ESUS at markedly different risks of AFDAS. A Graz AF Risk Score [&ge;]4 was also independently associated with recurrent ischemic stroke. These findings support a risk-adapted approach to cardiac rhythm monitoring after ESUS.

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Male Age and Sexual Maturity: Lipopolysaccharide-induced tumor necrosis factor influences sperm quality and reproduction in Anopheles culicifacies

Rohilla, P.; Saini, V.; Srivastava, V.; Yadav, P.; Sankhala, N.; Singh, T.; Sharma, G.; Tandon, G.; Tyagi, S.; Rani, J.; Dixit, R.

2026-09-01 developmental biology 10.64898/2026.08.31.748190 medRxiv
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Elucidating the biological and molecular mechanisms that govern male fertility and mating behavior in mosquitoes is critical for optimizing genetic and sterile insect technique-based vector control strategies. Here, we examined age-related changes in male reproductive capacity in Anopheles culicifacies, using female egg output as an indirect indicator of male fertility. Our results demonstrated that male reproductive age follows a non-linear pattern of fertility. Morphometric analysis from emergence to day 13 post-eclosion revealed a strong correlation between seminal vesicle capacity and female fecundity, suggesting that age-dependent gonadal development directly influences reproductive potential. At the molecular level, we identified AcLITAF6 as a key regulator of male reproductive homeostasis. RNAi-mediated knockdown of AcLITAF6 impaired apoptosis-associated and phagocytic clearance, reduced sperm viability, and decreased female productive outcomes. Conclusively, we reveal a previously unrecognized role of LITAF in sperm quality control and male reproductive fitness, highlighting AcLITAF6 as a potential target for mosquito population suppression strategies.