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Science Bulletin

Elsevier BV

Preprints posted in the last 90 days, ranked by how well they match Science Bulletin's content profile, based on 21 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

1
Diversifications of both the three domains of life and SARS-CoV-2 possibly driven by biases between amino acid biosynthetic families

Li, D. J.

2026-06-30 evolutionary biology 10.64898/2026.06.22.733698 medRxiv
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All cellular life forms fall under the three-domain classification of life, raising a fundamental evolutionary question: why does this classification feature three rather than two or four? To answer this question, a more general method, rather than the traditional one based on comparing small-subunit ribosomal RNAs, is required. The three-base periodicity in genomes is a common feature of both cellular life forms and viruses, which is species-specifically biased between amino acid biosynthetic families. Based on comparing such a common feature of all life forms, a global triangular diversification picture has been obtained, whose three angular regions correspond to the three domains, respectively. This mechanism of diversification of life attributes the evolutionary driving forces in diversification of the three domains of life to the biases between amino acid biosynthetic families. Notably, the same mechanism also applies to the contemporary diversification of SARS-CoV-2, whose reasonable results in turn corroborate the above explanation of primordial diversification of life and in addition shed light on the mechanism of speciation.

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Mammalian TMC Family Proteins are Mechanically Gated Ion Channels

Fu, S.; Dong, J.; Luo, X.; Xie, T.; Li, W.; Luo, Y.; Yan, Z.

2026-08-20 neuroscience 10.64898/2026.08.18.745354 medRxiv
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Every known life form senses and reacts to mechanical forces. These mechanical stimuli can be converted into electrical signals by mechanically gated ion channels, a transduction cascade pivotal to numerous physiological functions including touch, hearing, mechanical pain, circulation, gastrointestinal function, and mechanical loading in various tissues. Despite continuous efforts, numerous mechanically gated ion channels with the mechanotransduction process underlying these physiological functions remain unidentified. Here, we focused on the transmembrane channel-like (TMC) protein family expressed in the cultured cells to identify those with potential mechanosensitive activity. Remarkably, in contrast to human TMC1/2 (HsTMC1/2), human TMC3-8 (HsTMC3-8) proteins are localized to the plasma membrane when heterologously expressed in the cultured cells. Further experiments revealed that mechanical poking stimuli can effectively activate HsTMC3-8. In addition, HsTMC3-8 induced stretch-activated currents and elicited well-resolved single-channel activities in response to negative pressure stimulation. The mutants near the putative pore region altered reversal potentials (Erev) of HsTMC3-8, suggesting that TMC3-8 are likely pore-forming subunits of ion channels. In summary, we proposed that TMC proteins are the largest mammalian mechanically gated ion channel family.

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A Vision-Language Model for Coronary Angiography Interpretation and Clinical Decision Support

Li, Z.; Sun, Y.; Jiang, C.; Pan, T.; Zhou, Y.; Wang, C.; Pan, L.; Zhang, X.; Yang, Z.; Yu, Z.; Xiao, Z.; Chen, J.; Huang, Y.; Sun, R.; Gan, Y.; Li, X.; Zhang, B.; Zhang, Z.; Wang, X.; Han, L.; Qi, Y.; Cheng, Y.; Liang, Y.; Ge, J.

2026-08-12 cardiovascular medicine 10.64898/2026.08.11.26360095 medRxiv
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BACKGROUND: Coronary angiography remains the reference standard for diagnosing coronary artery disease and guiding revascularization, yet its interpretation requires expert integration of multi-view anatomy, lesion morphology and procedural context. Existing artificial intelligence approaches are largely task-specific, annotation-dependent and limited in capturing the semantic relationship between angiographic findings and interventional decision-making. Whether large-scale vision-language pretraining can enable transferable foundation-model representations for invasive coronary imaging remains unknown. METHODS We developed CAG-MIND, a domain-specific vision-language foundation model for coronary angiography, using 135,475 CAG examinations paired with procedural reports, comprising 812,850 angiographic videos from Zhongshan Hospital and Shanghai Geriatric Medical Center. Each case consisted of standardized six-view angiographic acquisitions paired with structured procedural semantics extracted from routine reports using a large language model-assisted pipeline. The model was pretrained by aligning multi-view angiographic representations with report-derived semantic embeddings through bidirectional contrastive learning. Performance was evaluated under zero-shot and supervised fine-tuning settings across 11 downstream tasks grouped into structural abnormality detection, atherosclerotic plaque assessment, and interventional decision prediction, using both an internal validation cohort and an independent external test cohort. RESULTS CAG-MIND demonstrated robust performance across all three task categories. In the zero-shot setting, the model achieved mean AUROCs of 0.686 in the internal validation cohort and 0.745 in the external test cohort, indicating transferable multimodal representations without task-specific supervision. Following supervised fine-tuning, the mean AUROC increased to 0.827 and 0.846, respectively, with excellent performance for coronary stenosis detection (AUROC 0.940 in both cohorts), balloon/stent prediction (0.900 and 0.907), and CABG recommendation (0.877 and 0.875). Compared with representative biomedical vision-language models and conventional image-based architectures, CAG-MIND consistently achieved superior performance in both zero-shot and supervised settings and remained superior to fully fine-tuned competing models when trained with only 10% of the labelled data. Grad-CAM visualization demonstrated anatomically plausible lesion-focused attention, supporting the interpretability of the learned representations. CONCLUSIONS CAG-MIND is, to our knowledge, the first large-scale vision-language foundation model for coronary angiography trained at more than 100,000-patient scale. By aligning standardized multi-view angiographic videos with report-derived procedural semantics, CAG-MIND enables robust zero-shot transfer, data-efficient fine-tuning and cross-center generalization. These findings support domain-aligned multimodal pretraining as a scalable foundation-model paradigm for invasive cardiovascular imaging and future cath-lab decision support.

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NR4A3 knockdown ameliorates metabolic dysfunction-associated steatotic liver disease through ATF3 transcriptional repression

Liao, H.; Qin, B.; Zhou, L.

2026-06-30 pathology 10.64898/2026.06.24.734361 medRxiv
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Objectives; The role of nuclear receptor subfamily 4, group A, member 3 (NR4A3) in hepatic steatosis, inflammation, and insulin resistance (IR) within the context of metabolic dysfunction-associated steatotic liver disease (MASLD) remains largely underexplored. Consequently, this study aimed to examine NR4A3's impact on MASLD and the potential underlying mechanisms. Methods; We aimed to elucidate the functional role of NR4A3 in MASLD through its knockdown in cell culture and animal models. To establish the cell culture model of MASLD, LO2 cells were treated with free fatty acids (FFAs), while male C57BL/6 mice were fed a high-fat diet (HFD) to create the animal model. NR4A3 knockdown was achieved using specific short hairpin RNA (NR4A3-shRNA) in the mice model and three small interfering RNAs (NR4A3-siRNAs) in the cell culture model. The lipids content, fatty acid synthesis, inflammatory factors, and IR were then assessed with and without NR4A3 knockdown. Furthermore, the underlying mechanism through which NR4A3 exerts its influence was explored by analyzing the interaction between NR4A3 and activating transcription factor 3 (ATF3). Results: In the cell culture experiments, the knockdown of NR4A3 significantly decreased the lipids content, fatty acid synthesis, and inflammatory factors in the LO2 cells treated with FFAs in the NR4A3-shRNA group compared with those in the NC-shRNA control group. In the animal model experiments, NR4A3 knockdown in the HFD male C57BL/6 mice significantly ameliorated HFD-induced hepatic steatosis, inflammation, and IR. Mechanistically, the knockdown of NR4A3 downregulated the expression and transcriptional activity of ATF3, resulting in an impaired ATF3 function. ATF3 overexpression significantly reversed lipid accumulation decline and reduced inflammation after NR4A3 knockdown. Conclusion: The downregulation of NR4A3 alleviates MASLD by modulating ATF3, suggesting this may be a promising therapeutic target.

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Lactylation of Influenza Virus Polymerase Acidic Protein Promotes Viral Replication and Pathogenicity

Tu, S.; Du, Y.; Liang, W.; Xu, X.; Zou, J.; Yang, Y.; Xiong, C.; Li, Y.; Jiang, M.; Ouyang, A.; Chen, T.; Jin, M.; Chen, H.; Zhou, H.

2026-07-10 microbiology 10.64898/2026.07.10.737663 medRxiv
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Influenza virus poses a potential risk of triggering the next global pandemic. In-depth investigation into the mechanisms underlying influenza virus replication and pathogenicity will provide robust support for controlling influenza virus infection. Although post-translational modifications are known to regulate viral infection, the role of lactylation in influenza virus replication remains elusive. In this study, influenza virus ribonucleoprotein complex subunits are found to be lactylated. Specifically, ATAT1 promotes viral polymerase acidic protein (PA) lactylation and enhances viral replication. In contrast, SIRT1 mediates de-lactylation of PA and exerts an inhibitory effect on viral replication. Further investigations reveal lactylation of PA at residues K605 and K609 is essential for viral replication and pathogenicity. Mechanistically, PA K605/609 residues are localized at the interaction interface of the ANP32-mediated polymerase asymmetric dimer; mutation at these residues inhibits polymerase asymmetric dimerization, thereby impairing RNA production during viral genome replication. Collectively, this study uncovers a novel mechanism by which influenza virus hijacks host enzymes to mediate PA lactylation, and expands the molecular regulatory network of influenza virus infection.

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Virus-human protein-protein interactions predict viral phenotypes

Zhang, Z.; Feng, Y.; Ge, X.; Meng, X.; Peng, Y.

2026-06-13 bioinformatics 10.64898/2026.06.12.732009 medRxiv
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Viral phenotypes such as host and tissue tropism are critical determinants of viral infection and transmission. Inferring viral phenotypes presents unique challenges compared to cellular organisms, as viruses rely entirely on host machinery for replication and survival. Current methods for predicting viral phenotypes mainly rely on viral genomic data, often overlooking host-related information. Here, we evaluated the utility of predicted virus-human protein-protein interactions (PPIs) in inferring diverse viral phenotypes using machine-learning algorithms. For predicting human infectivity, a PPI-based machine learning model outperformed both virus genomic and protein sequence-based models that used large language model embeddings. It also surpassed previous methods that incorporated both viral and host genomic data. The human proteins identified by the model were significantly enriched in functions related to viral infection and immune response. In predicting various phenotypes of human RNA viruses, PPI-based models performed better than virus sequence-based models in forecasting virulence, human transmissibility and transmission routes, while showing comparable performance to genomic sequence-based models in predicting tissue tropism. Finally, we demonstrated that a PPI-based model could distinguish high-risk HPV genotypes from low-risk ones. Proteins associated with high-risk HPV were involved in apoptosis and immune regulation, whereas those linked to low-risk HPV were enriched in telomere maintenance and DNA repair. Collectively, this study is the first to demonstrate the value of predicted virus-human PPIs in inferring viral phenotypes, thereby enhancing our understanding of the molecular mechanisms underlying these phenotypes. It also provides effective tools for risk assessment of emerging viruses, contributing to improved pandemic preparedness.

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Identification and molecular characterization of a novel TYLCV isolate breaking bred-resistance to threaten tomato cultivar

Zhou, Y.;Jin, S.;Zhong, J.;Xiao, X.;Ding, M.;Zhao, L.;Guo, Z.

2026-06-17 Plant Biology 10.64898/2026.06.16.732612 medRxiv
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Tomato yellow leaf curl virus (TYLCV) is a devastating viral pathogen threatening agricultural crops globally. In this study, we identified a novel TYLCV isolate (TYLCV-YN6244), which caused viral epidemic in resistant tomato cultivars at Yuanmo county, Yunnan Province of China. We determined the complete genome of TYLCV-YN6244 and found it encoded six viral proteins characteristic of Geminivirus. We identified its V2 protein as a potent viral suppressor of RNA silencing (VSR), and generated infectious clone of wildtype TYLCV-YN6244, or V2-defective TYLCV-YN6244 (TYLCV-YN6244-{Delta}V2) in which V2 was deleted. Both of infectious clones were capable of systemically infecting tobacco and tomato. However, TYLCV-YN6244 but not TYLCV-YN6244-{Delta}V2 could cause disease symptoms in wildtype tobacco or tomato plants, and viral accumulation was drastically reduced in plants infected with TYLCV-YN6244-{Delta}V2 compared to TYLCV-YN6244 while the efficiency of virus-derived small interfering RNAs (vsiRNAs) biogenesis was conversely increased in plants infected with TYLCV-YN6244-{Delta}V2. Surprisingly, small RNA profiling indicated that 21nt and 22nt rather than 24nt vsiRNAs were predominantly produced in tomato plants infected with either TYLCV-YN6244 or TYLCV-YN6244-{Delta}V2. Furthermore, transcriptome analyses revealed that TYLCV-YN6244 or TYLCV-YN6244-{Delta}V2 infection differentially modulated metabolism and defense-related pathways in tomato, probably underlying distinct viral pathogenicity and disease symptoms induced in plants. Overall, our research not only identified a novel pathogenic TYLCV isolate but also characterized molecular biology and host response in tomato with infectious clones firstly developed, with implications in untangling virus-host interaction for developing novel resistance in crop tomato.

8
Learned ultrasound segmentation and deformable CT fusion for augmented reality endovascular surgery

Dillon, T. M.; Quevedo Moreno, D.; Rutherford, E. K.; Ayers, B.; Salomon, B.; Kubi, B.; Thomas, J.; Roche, E.

2026-07-17 cardiovascular medicine 10.64898/2026.07.15.26358084 medRxiv
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Minimally invasive endovascular procedures offer reduced surgical trauma, shorter recovery times, and improved outcomes, but rely on 2D fluoroscopic X-ray imaging, which provides limited depth perception and exposes patients and clinicians to ionizing radiation. Here we present an augmented reality (AR) system that fuses intravascular ultrasound (IVUS) and electromagnetic (EM) position tracking with preoperative computed tomography (CT) to produce an anatomically accurate, deformation-corrected navigational reference. A robotic device performs ECG-gated pullback of the IVUS probe, capturing 4D aortic motion across the cardiac cycle. We introduce a deep learning architecture for extracting vascular lumen boundaries and side-branch orifices from artifact-prone IVUS streams, and a semantically driven non-rigid CT-IVUS fusion pipeline robust to false positive landmarks. We evaluate the platform with trained surgeons in benchtop phantom studies and in-vivo ovine models, and demonstrate its application to fenestrated endovascular aneurysm repair (FEVAR). Compared to fluoroscopy alone, AR guidance significantly reduces cannulation time, radiation exposure, and cognitive workload, while improving procedural efficiency and safety. Our IVUS-EM and CT aortic datasets are released open source.

9
Enhancing Recombinant Vector Assembly Efficiency: A Novel Methodological Approach

YUAN, S.; Jiang, H.; Wang, H.; Fu, M.; Wang, J.; Liu, Z.; Li, Y.

2026-08-01 biochemistry 10.64898/2026.07.30.741931 medRxiv
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With the rapid development of modern biotechnology, DNA vectors have become fundamental tools for inserting, transferring, and expressing specific gene sequences in various fields such as gene cloning, gene expression, gene editing, and gene therapy. However, when dealing with complex structured DNA sequences, traditional vector construction methods face challenges with low connection efficiency. This study proposes a new method for constructing recombinant vectors by employing a strategy of high-temperature treatment followed immediately by placement on ice, effectively reducing the complexity of DNA structures and enhancing the efficiency of PCR product-vector connection, thereby improving the construction efficiency of recombinant vectors. This paper describes the technical details of the method, experimental validation, and applications in gene cloning, gene recombination editing, and the preparation of gene therapy drugs, providing a new efficient tool for molecular biology experiments.

10
The Origin and Evolution of Protein Synthesis: A Co-Adaptation Flexible-Rigid Docking Model Based on First-Principles Reasoning

Zhao, D.; Yang, Y.; Sun, J.; Zhang, J.; Duan, H.; Tan, Y.; Liu, l.

2026-06-11 evolutionary biology 10.64898/2026.06.11.730790 medRxiv
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Although the "RNA world" hypothesis suggests that RNA played a crucial role in the origin of life [7], the functional framework of RNA in prebiotic protein synthesis and the mechanisms of genetic code formation during the prebiotic period remain poorly understood. Here, using the prebiotic "primordial soup" as a model, we reconstructed the detailed steps that would yield a protein with a stable ordered amino-acid sequence in the "primordial soup" at the prebiotic period. In the "primordial soup", a large number of medium- to large-sized biomolecule-like substances--such as RNA-like and protein-like molecules of various sizes and shapes, as well as related polymers like amino-acid-RNA-like etc.--did generate and accumulate. Moreover, protein-like and RNA-like molecules formed even more intricate complexes. These complexes bound free mRNA-like molecules through complementary base pairing. Subsequently, with an extremely low probability, two adjacent amino-acid-RNA-like molecules became bound to this free mRNA-like molecule, and their amino acids underwent a condensation reaction by the complexes, producing peptides and eventually proteins or polypeptides. This free mRNA-like molecule exhibits a certain flexible structure, whereas the super-large complexes formed by protein-like and RNA-like molecules (which possess certain activities) and the amino-acid-RNA molecules exhibit relatively rigid structures. Long-term evolution and mutual selection led to the emergence of proteins with stable amino acid sequences and moderate catalytic activity. In this way, the nucleotide information embedded in such mRNA-like molecules indirectly express through protein synthesis--a process we term the "A Co-Adaptation Flexible-Rigid Docking Model", where flexible mRNA-like molecules dock onto rigid complexes to enable ordered peptide formation. Finally, we show how trinucleotide codons emerge naturally from the flexible-rigid docking constraints.

11
Incorporation of single-neuron projectome-based connectivity motifs enhances the cortex-specific performance of artificial neural networks

Sun, Y.; Yao, W.; Zhang, J.; Song, W.; Zhao, X.; Hao, C.; Chen, X.; Zeng, S.; Jia, S.; Yang, Y.; Chen, X.; Xiao, X.; Poo, M.-m.; Sun, Y.; Xu, B.; Zhang, T.

2026-06-17 neuroscience 10.64898/2026.06.12.732007 medRxiv
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The organizational principles of natural neural networks could inspire the new architecture design of artificial neural networks (ANNs). Analysis of single-neuron connectomes of mouse brains revealed distinct profiles of three-node connectivity motifs in various cortical areas and hippocampal formation. A connectome-informed neural network algorithm ("CINA") was developed to incorporate natural connectivity motifs into ANN algorithms represented by recurrent neural network (RNN) and transformer-based large language model (LLM). We found that incorporation of the average profile of cortical motifs improved the RNNs performance in noise-resistant categorization and motor learning benchmark tasks, as compared with RNNs with random connectivity. Notably, incorporating cortex-specific motifs further elevated the RNNs performance in tasks related to the cortical function, and this effect was enhanced by artificially increasing the bias in the motif profile. Similar experimental results were verified on an LLM using Motif-Transformer for natural language question answering and brain-signal decoding tasks. Graph-theoretic analyses showed that incorporating natural motifs drove the emergence of modular and small-world properties in ANNs. Together, we demonstrated not only connectome-inspired optimization of ANN architecture but also functional significance of specific motif profiles in various cortices.

12
NF1 deficiency induces metabolic reprogramming and epithelial-mesenchymal transition in glioblastoma

Dong, Q.;Shi, J.;Yin, H.;Wang, B.;Niu, L.;Wang, X.;Dai, J.;Li, Q.;Pan, Y.;Yuan, G.

2026-06-19 Cancer Biology 10.64898/2026.06.17.733017 medRxiv
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BackgroundMetabolic reprogramming is a common occurrence in tumor cells, where enhanced glycolysis promotes cell growth, invasion and migration. NF1 is tumor suppressor gene that downregulates the encoded neurofibromin protein. However, the effects of NF1 on energy metabolism and epithelial-mesenchymal transition (EMT) in glioblastoma multiforme (GBM), as well as the underlying molecular mechanisms, remain unclear. MethodsCRISPR/Cas9 gene editing technology was employed to construct GBM cell lines with NF1 gene mutations. Metabolomics was utilized to examine the impact of NF1 on metabolic remodeling in GBM. The Seahorse XF24 extracellular flux analyzer was used to detect the effect of NF1 knockdown on glycolysis and mitochondrial oxidative phosphorylation in GBM cells. Wound healing assay and Transwell chamber assay were utilized to detect the effect of NF1 on GBM cell invasion. Orthotopic tumor model in nude mice was established to explore the role of NF1 in vivo. In addition, Co-IP, western blotting, and immunofluorescence were used to explore the changes of key enzymes in glycolysis and mitochondrial oxidative phosphorylation and the relationship between NF1 and MFN1. ResultsThe expression of NF1 is decreased in glioma tissues and is significantly correlated with patient prognosis. NF1 knockdown may promote the invasion, migration, and EMT of GBM cells. At the same time, the activation of the AKT/mTOR signaling pathway promotes aerobic glycolysis in GBM cells, promotes mitochondrial division through targeted regulation of MFN1, and inhibits mitochondrial oxidative phosphorylation. NF1 deficiency promotes EMT in GBM cells by enhancing aerobic glycolysis and mitochondrial division. ConclusionNF1 deficiency promotes GBM glycolysis by activating the AKT/mTOR signaling pathway and inhibits the mitochondrial oxidative phosphorylation by regulating MFN1; NF1 deletion promotes GBM EMT by remodeling the pattern of energy metabolism.

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Ferumoxytol dynamic contrast-enhanced MRI for in vivo longitudinal cotyledon perfusion assessment with pathology correlation in a rhesus macaque thrombotic injury model

Liu, R.-Y.; Keding, L. T.; Edmondson, R.; Vazquez, J.; Antony, K. M.; Johnson, K. M.; Shah, D. M.; Golos, T. G.; Stanic, A. K.; Wieben, O.

2026-08-10 pathology 10.64898/2026.08.04.742075 medRxiv
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IntroductionWhile placental perfusion and pathology jointly affect pregnancy outcomes, cotyledon-specific perfusion across gestation and its correlation with local injury is not yet well understood. Ferumoxytol dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) offers a promising way to noninvasively identify cotyledons across gestation and quantify longitudinal cotyledon-specific perfusion changes. Additionally, intraplacental injection of bioactive fibrin sealant allows us to model thrombotic placental injury and further assess cotyledon-level relationships between perfusion and significant injury. MethodsPregnant rhesus macaques (N=13) received intrauterine saline or fibrin sealant injections at gestational day (GD) [~]101 and underwent ferumoxytol DCE-MRI at GDs [~]100, 115, and 145. Placental perfusion domains derived from contrast arrival time were segmented at each imaging time point and matched to cotyledons identified following tissue collection by cesarean section, with cotyledon perfusion quantified longitudinally and correlated with cotyledon-specific quantitative histopathology. ResultsAll pregnancies were successfully carried to term. Fibrin sealant injections induced significantly higher levels of placental pathology compared to saline controls. MRI-derived perfusion domains were largely consistent across gestation and showed predominantly one-to-one correspondence with term cotyledons, with successful perfusion-pathology pairing achieved in 153 cotyledons. Longitudinal cotyledon perfusion changes showed significant positive correlations with villous agglutination injuries. ConclusionsFeasibility of noninvasively tracking placental cotyledon perfusion using ferumoxytol DCE-MRI was demonstrated, and the efficacy of the rhesus macaque thrombotic injury model was confirmed. The positive perfusion-pathology correlations suggested intrinsic placental regulatory mechanisms and functional plasticity. This new framework is promising for future translational studies and validation of ex vivo cotyledon perfusion models. HighlightsO_LILongitudinal tracking of placental perfusion domains with ferumoxytol MRI C_LIO_LISuccessful matching of cotyledons and MRI-derived perfusion domains C_LIO_LIConfirmed thrombotic injury-model induced cotyledon pathology C_LIO_LIMaternal perfusion compensation in presence of villous pathology C_LI

14
West Nile virus capsid protein promotes viral replication and pathogenesis through PKCα-dependent lamin phosphorylation and nuclear deformation

Maezono, K.; Thammahakin, P.; Kataoka, M.; Suzuki, T.; Eguchi, H.; Thuy, D. T. N.; Yamaguchi, T.; Ota, A.; Itakura, Y.; Tabata, K.; Sawa, H.; Yoshii, K.; Kariwa, H.; Kobayashi, S.

2026-07-23 microbiology 10.64898/2026.07.17.739139 medRxiv
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The genus Orthoflavivirus comprises several medically important pathogens such as the West Nile virus (WNV), which causes encephalitis in humans. Although viral replication occurs in the cytoplasm, the capsid (C) protein of the orthoflavivirus is localized to both the cytoplasm and nucleus. Nuclear C protein contributes to viral replication and disease progression. However, the underlying mechanisms remain unclear. Here, we investigated whether the WNV C protein induces nuclear deformation and examined the underlying mechanism. We also assessed the contribution of this deformation to viral replication and pathogenesis. WNV infection and C protein expression induced morphological alterations in the nuclear lamina, leading to nuclear deformation. C protein expression enhanced lamin phosphorylation and the disassembly of the polymerized lamin network. In addition, C protein interacted with protein kinase C alpha (PKC) and localized PKC near the nuclear lamina. Downregulation of PKC expression inhibited C protein-induced lamin phosphorylation and nuclear deformation. In addition, both the downregulation of PKC expression and pharmacological inhibition of PKC reduced WNV replication. In contrast, the expression of phosphorylation-deficient lamin mutants attenuated the inhibitory effect of downregulated PKC expression on WNV replication. Furthermore, the pharmacological inhibition of PKC increased the survival rate of WNV-infected mice and suppressed both viral replication and nuclear deformation in the brain. Collectively, these results demonstrate that C protein remodels the nuclear lamina architecture through the PKC-lamin pathway, and that virus-induced nuclear deformation contributes to WNV replication and pathogenesis. Author summaryThe West Nile virus (WNV), a neurotropic orthoflavivirus, causes severe neurological diseases in humans. In host cells, orthoflaviviruses exclusively replicate in the cytoplasm. However, their capsid (C) proteins are localized to both the nucleus and cytoplasm. Although the nuclear C protein has been implicated in viral replication and disease progression, its underlying mechanisms remain unclear. Here, we demonstrate that the WNV C protein induces nuclear deformation, accompanied by the phosphorylation of lamin and disassembly of the nuclear lamina, a structural scaffold that maintains the nuclear shape. The C protein promotes the localization of PKC, a host kinase protein, near the nuclear lamina. Suppression of PKC expression or activity reduces lamin phosphorylation, nuclear deformation, and WNV replication. Importantly, pharmacological inhibition of PKC in WNV-infected mice reduced nuclear deformation and viral replication in the brain and improved survival rates. Collectively, our findings identify the host nucleus as an important site of WNV-host interaction and provide a new perspective that WNV, despite replicating in the cytoplasm, remodels host nuclear architecture to promote viral replication and pathogenesis.

15
Assembly of the ATP-driven cobalt chelatase

Zhou, Y.-l.; Yuan, H.; Wu, Y.-c.; Wang, J.; Chen, H.; Yao, L.; Wang, M.; Wang, X.; Wang, J.; He, C.; Chen, X.; Liu, L.

2026-07-22 biochemistry 10.64898/2026.07.21.739949 medRxiv
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Nature has evolved two distinct chelatase families to catalyze the insertion of metal ions into tetrapyrrole macrocycles. Whereas the single-subunit ATP-independent chelatases have been widely investigated, little is known about the three-subunit ATP-driven chelatases. Here we show step-wise assembly of the ATP-driven cobalt chelatase CobSTN that is essential for aerobic vitamin B12 biosynthesis. The motor subunit CobS fits into a hexameric or dodecameric spiral, and forms complex with the adaptor subunit CobT. Upon binding to adenine nucleotide, the spiral transforms to an asymmetrical ring and CobT synergistically rotates and inserts a distinctive shaft into the ring hole. The largest subunit CobN interacts with the opposite side of CobT from the CobS ring, and hence the holoenzyme is assembled.

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Systemic, RPE-directed AAV-Tyrosinase therapy restores ocular pigmentation in an OCA1 mouse model

Larimer-Picciani, A. M.; Jacob, L. B.; Sullinger, K. J.; Kriebel, W. G.; Sahel, J.-A.; Byrne, L. C.

2026-07-09 molecular biology 10.64898/2026.07.01.735814 medRxiv
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Oculocutaneous albinism type 1 (OCA1) is a pigmentation disorder caused by biallelic tyrosinase (TYR) mutations, an essential enzyme for melanin synthesis. TYR inactivity results in loss of hair, skin, and eye pigment, which is detrimental for ocular function. Hypopigmentation of iris, retinal pigment epithelium (RPE), and choroid results in severe photosensitivity and low visual acuity. There are currently no FDA-approved pigment restoring therapies for OCA1, making therapeutic development an unmet clinical need. To address this gap, we have advanced an adeno-associated viral (AAV)-mediated Tyr replacement approach for OCA1 ocular pigment restoration. We evaluated the optimal viral delivery strategy and vector cell-type specificity for iris, RPE, and choroid pigmentation in an OCA1 mouse model, testing intraocular and systemic viral delivery methods in conjunction with viral constructs of varying RPE-specificity. Early, systemic delivery of an RPE-directed AAV-Tyr construct, AAV9.2yf-VMD2-Tyr, achieved widespread ocular pigment rescue with minimal off-target expression in non-ocular tissues. Animals treated with AAV9.2yf-VMD2-Tyr demonstrated reduced photophobic behavior compared to untreated controls, indicating that ocular pigmentation restores a debilitating functional consequence of OCA1. Our findings establish a foundation for clinical translation of an AAV-TYR therapy aimed at improving light sensitivity, glare, and low vision through pigment restoration in patients with OCA1.

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Spatiotemporal Patterns and Structural Substrates of Individual Functional Variability in Youth

Yang, Z.; Dong, X.; Zeng, D.; Chu, L.; He, Y.; Zhang, J.; Li, Q.; Zhang, Y.; Sun, L.; Wang, X.; Li, S.

2026-06-18 neuroscience 10.64898/2026.06.16.730254 medRxiv
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Youth is a period of emerging individuality and extensive neural remodeling, yet how functional brain individuality is organized across development remains unclear. Prior work has often conflated variability in functional topography and connectivity, highlighting the need to examine them separately to better understand how functional individuality relates to brain structure and cognition. Here we used individualized functional parcellation in a large multimodal developmental cohort to separately quantify variability in individualized functional parcellation (vIFP) and variability in functional connectivity (vFC). Both forms of variability followed the sensorimotor-association axis and were greatest in the association cortex. vIFP increased significantly with age, whereas vFC showed regionally specific maturation without a significant whole-brain increase. Both trajectories showed a common mid-adolescent inflection at 14-16 years, marking a window of accelerated functional individualization. Despite shared spatial and temporal organization, vIFP and vFC showed dissociable links to structure and cognition. vIFP was more strongly coupled to structural variability, whereas vFC was more strongly associated with cognitive variability. These findings reveal convergent and divergent developmental principles of topographic and connectional functional variability, highlighting their complementary roles in structural constraints and cognitive specialization.

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Structural Bioinformatics of Four Human Aquaporins and Their Water-Soluble QTY Analogs

Zhang, S.; Xiao, E.

2026-06-30 bioinformatics 10.64898/2026.06.24.734367 medRxiv
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Human aquaporins (AQPs) are essential membrane channels, yet their inherent hydrophobicity complicates structural and functional studies. We present the systematic application of the QTY code to human AQPs, integrating it with AlphaFold 3 structure prediction to design and validate that four-representative human AQPs (AQP1, AQP3, AQP4, AQP7) can be converted into water-soluble analogs while maintaining their conformation. This approach features a novel platform for editing challenging membrane proteins. The QTY code was applied to the transmembrane regions of the selected four AQPs. Subsequently, the water-soluble QTY analogs of the four AQPs were predicted using AlphaFold 3. The predicted structures were superposed with CyroEM- or X-ray-determined native structures in PyMOL. Further analyses included root-mean-square deviation (RMSD) calculations, visualization of hydrophobic surface reduction, and inspection of conserved protein-ligand binding ability. After applying the QTY code, sequence changes between native AQPs and their QTY analogs was significant (42.86-48.80%). Nevertheless, their structures superposed well in analyses, with only slight deviations (RMSD < 0.6 [A]). In addition, the surface hydrophobicity of all QTY-edited AQPs was significantly reduced. Importantly, molecular contacts between the cholesterol ligand and protein were largely preserved for both native AQP1 and its QTY analog. Finally, all AlphaFold3-predicted structures for AQPs have high confidence values (pLDDT > 90; pTM ~0.83), supporting the reliability of the predicted structures. The findings demonstrate that membrane protein hydrophobicity can be edited and reduced without compromising fold integrity or functional architecture. Integration of the QTY code with AlphaFold 3 affords a high-throughput platform for designing water-soluble, structurally faithful analogs of challenging membrane proteins. Such a strategy can provide a potent platform for detergent-free biochemical studies and water-soluble analogs for therapeutic monoclonal antibody discoveries, thus advancing research of this pharmacologically important protein family.

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Automated language impairment screening in acute stroke using connected speech

Pugalenthi, L. S.; Schnur, T. T.

2026-08-17 cardiovascular medicine 10.64898/2026.08.14.26360474 medRxiv
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Connected speech is essential for everyday communication, but clinical constraints and patient fatigue limit detailed evaluation in acute stroke (<1-week post-stroke). Bedside assessments may sample discourse but rarely quantify language impairment (LI) in connected speech, leaving patient communication poorly characterized. We analyzed brief story retellings from 86 patients with left-hemisphere stroke (~4 days post-stroke; 63 classified with LI using composite clinical and naming criteria). From transcripts generated with automatic speech recognition, we derived discrete linguistic features and embeddings with Large Language Models (LLMs). An ensemble of embedding-based classifiers distinguished patients with and without LI with 90% balanced accuracy (79% sensitivity, 100% specificity), outperforming independent embedding and discrete-linguistic-based classifiers, showing distinct LLMs contributed complementary information. Adding the discrete-linguistic-based classifier to the ensemble did not improve balanced accuracy but modestly increased sensitivity at the expense of specificity. We provide proof of concept for a fast, largely automated discourse screener of acute LI.

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Promfusion: a synthetic fusion promoter enabling enhanced and balanced photoreceptor transgene expression

Tran, S.; Trinquier, J.; Van Meter, T.; Zin, E. A.; Nanteau, C.; Riancho, L.; Potey, A.; Slembrouck-Brec, A.; Delmas, M.; Ferrari, U.; Goureau, O.; Dalkara, D.

2026-06-09 genetics 10.64898/2026.06.05.730342 medRxiv
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Achieving efficient and balanced transgene expression in both rods and cones remains a major challenge in retinal gene therapy. Current promoters either lack specificity or fail to provide sufficient cellular coverage and expression level. To address this limitation, we developed and evaluated two fusion promoters, Pikali and Nocchu, by combining PR1.7, a cone-specific promoter and GRK1, a promoter most active in rods. Here, we show that Pikali and Nocchu outperform their parental promoters, driving broader and more balanced GFP expression in rods and cones of human iPSC-derived retinal organoids. These constructs achieved transduction in 30% to 45% of photoreceptors, with higher expression levels than GRK1 and broader cellular coverage than PR1.7. Our findings establish Pikali and Nocchu as excellent candidates for retinal gene therapy, overcoming the limitations of existing promoters. By combining specificity, efficiency, and extensive photoreceptor targeting, these fusion constructs represent a novel and promising strategy for next-generation gene therapy vectors, addressing inherited retinal dystrophies and advancing clinical translation.