Biology subjects

Kim, M.

Publications and source records attributed to Kim, M..

At least 55 records · Page 3Linked to original sources

bioRxiv2026

Cryptic Evolution of Heteroresistance as Adaptation to Treatment Interruptions

The evolution of antibiotic resistance is traditionally understood as a selective sweep to fixation, yielding easily detectable, population-wide resistance. Many clinical isolates, however, exhibit a subtle phenotype in which resistance remains hidden within a susceptible majority despite a clonal genetic background: a phenomenon clinically recognized as heteroresistance (HR). Treatment failure driven by HR has been widely reported across bacterial and fungal infections and in cancer therapy. To understand when and how HR evolves, and why it is selected over classical population-wide resistance, we conducted de novo evolution experiments starting from susceptible Escherichia coli and analyzed the genetic changes and fitness effects in the evolved strains. Prolonged gaps in antibiotic exposure are required for HR to evolve, implicating treatment interruptions as a key driver. HR emerges rapidly and reproducibly with minimal antibiotic use, yet its emergence is not readily detected by routine susceptibility testing. Unlike classical resistance, an evolved HR population partitions at the single-cell level into multiple phenotypes with distinct growth-resistance trade-offs. Their relative abundance shifts dynamically with antibiotic exposure, enabling robust population survival while avoiding the constitutive fitness burden associated with classical resistance. Despite this phenotypic flexibility, stable single mutations including a missense substitution and a short in-frame deletion are sufficient to generate HR, indicating a low evolutionary barrier. Additionally, we found that clinical isolates exhibit genetic and fitness signatures resembling those of our lab-evolved strains, suggesting that clinical HR emerges through the selective mechanism uncovered in our experiments. Together, our results establish HR as a readily evolvable adaptive strategy under treatment interruptions that leverages phenotypic flexibility to maintain resistance at minimal fitness cost, providing mechanistic insight into its emergence and prevalence.

evolutionary biology↗

bioRxiv2026

Longitudinal Changes in Intracortical Excitability During Ramadan Fasting: A Paired-Pulse Transcranial Magnetic Stimulation Study

Ramadan fasting represents a natural model of prolonged daily intermittent fasting associated with metabolic and circadian alterations. This study investigated longitudinal changes in intracortical excitability across pre-, mid-, and post-Ramadan timepoints in healthy adults observing Ramadan fasting. Thirty fasting participants underwent paired-pulse transcranial magnetic stimulation at three timepoints (pre-, mid-, and post-Ramadan). A non-fasting control group (n = 11) was assessed at pre- and mid-Ramadan. Conditioned motor-evoked potentials were recorded at interstimulus intervals of 2-10 ms and normalized to unconditioned responses. A linear mixed-effects model assessed effects of Timepoint and interstimulus interval (ISI). Secondary outcomes included blood glucose, cognitive performance, sleep duration, and reaction time. A significant main effect of Timepoint (p < 0.001) indicated longitudinal modulation of intracortical excitability, with increased MEP ratios at mid-Ramadan and partial persistence post-Ramadan. The ISI effect confirmed the inhibition-facilitation gradient (p < 0.001). The Timepoint x ISI interaction was not significant (p = 0.566), indicating a global shift in excitability without ISI-specific modulation. Blood glucose and sleep duration decreased significantly at mid-Ramadan. Ramadan fasting is associated with a time-dependent increase in intracortical excitability, most appropriately interpreted as a generalized shift rather than selective modulation of inhibitory or facilitatory circuits. These changes occur in the context of concurrent metabolic and sleep alterations and may reflect combined influences of fasting-related metabolic state and reduced sleep duration; however, these factors cannot be disentangled within the present design.

neuroscience↗

bioRxiv2026

Cohesin extrudes chromatin loop unidirectionally through two modes of mechanisms in human cells

Cohesin is crucial for establishing 3D genome organization and functions. However, the in vivo mechanism of cohesin-mediated extrusion remains unsettled. Here, we investigated extrusion directionality using integrated genome mapping coupled with perturbation in human cells. By defining cohesin loading at NIPBL binding loci and anchoring at CTCF sites, we systematically characterized the aggregated and single-molecule trajectories of extrusion "stripes" and contact "dots" from and between individual cohesin loading and anchoring points. Our analyses delineated two dynamic modes of in vivo mechanism in which NIPBL/cohesin initiates extrusion at its loading sites in a one-sided manner; after encountering CTCF, CTCF/cohesin switches its extrusion direction backward and robustly extrude DNA unidirectionally until completing the convergent CTCF loop. Surprisingly, depleting CTCF resulted substantial increase of NIPBL/cohesin-mediated extrusion activity, which is further validated by in silico perturbation. These findings reveal novel mechanistic insights into how cohesin and CTCF orchestrate cohesin-mediated loop extrusion in vivo.

genomics↗

bioRxiv2026

Deep Learning-Guided Holotomography Reveals Early Structural Remodelling During Pluripotency Exit

Real-time assessment of human pluripotent stem cell (hPSC) quality is critical for reproducibility and safety in regenerative medicine, yet current methods are invasive, labor-intensive, or highly operator-dependent. We present DeepHOPE (Deep-learning-guided Holotomography for Pluripotency Evaluation), a non-invasive, automatizable, and statistics-driven platform that integrates three-dimensional (3D) refractive index imaging with deep learning to assess pluripotency. DeepHOPE performs robustly across diverse contexts, including germ-layer differentiation, retinoic acid-induced differentiation, and mid-reprogramming cultures, enabling streamlined cell production workflows and improving the efficiency of midbrain dopaminergic neuron differentiation through informed colony selection. Mechanistically, DeepHOPE detects minute colony-scale topological changes that precede molecular loss of pluripotency. These early changes are associated with rapid F-actin remodeling, including apical-to-basal redistribution during early differentiation. Consistent with a functional role for cytoskeletal regulation in state transitions, sustained reduction of actomyosin tension decreases pluripotency, identifying cytoskeletal dynamics as an upstream determinant of early pluripotency exit. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/720508v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@1d73508org.highwire.dtl.DTLVardef@1dab29aorg.highwire.dtl.DTLVardef@1039f76org.highwire.dtl.DTLVardef@da29a1_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2026

Genetic Characterization of the TAPBP and Its Haplotypic Association with BF2 in the Chicken Major Histocompatibility Complex

TAPBP is a key chaperone of the peptide-loading complex that facilitates peptide loading onto major histocompatibility complex class I (MHC I) molecules. This study characterized TAPBP alleles in Korean Native Chickens (KNCs), identified novel variants, and evaluated haplotypic associations with BF2. Thirty-six samples representing six KNC lines were genotyped using LEI0258 and the MHC-B SNP panel, and individuals homozygous at both markers were classified into 16 groups. The same samples were subjected to Sanger sequencing of TAPBP exons 3-8. Sequences were assembled and aligned against MHC-B reference haplotypes and the Red Junglefowl reference. Additional comparisons with "tapasin allele" datasets enabled the identification of novel variants. Six novel nucleotide variants were detected across exons 3-6, including one nonsynonymous substitution in exon 4 (D251H). This residue corresponds to position Q265 in human TAPBP and lies adjacent to residues involved in MHC I interaction, suggesting potential functional relevance. Furthermore, TAPBP exhibited high haplotype diversity (Hd = 0.93) and moderate nucleotide diversity ({pi} = 0.00892), with exon 5 showing the highest diversity ({pi} = 0.01). B9 was the most frequent haplotype at the nucleotide level, whereas B6/B24 predominated at the amino acid level. Comparison with BF2 data revealed haplotype-dependent pairing patterns: BF2-B9 consistently matched TAPBP-B9, whereas BF2-B6 was associated with distinct TAPBP nucleotide variants, indicating allelic diversification within a shared haplotypic background. Homozygosity at LEI0258 and the SNP panel corresponded with TAPBP homozygosity, supporting marker-based prediction. These findings highlight potential BF2-TAPBP associations and provide a foundation for understanding variation in MHC I peptide loading.

genetics↗

bioRxiv2026

Association between chronotype and dual-task gait cost across distinct cognitive domains in healthy young adults

Chronotype reflects individual circadian preference for timing of sleep, wakefulness, and peak performance and has been linked to variability in prefrontal cognitive function across the day. Whether chronotype independently relates to dual-task gait cost (DTC) and whether this relationship differs by cognitive task domain is unclear. Sixty-nine healthy young adults (37 female; mean age 21.3 years) completed the Morningness-Eveningness Questionnaire (MEQ). Spatiotemporal gait parameters were recorded with three-dimensional motion capture during single-task walking and three dual-task conditions: backward word spelling (5LWB; phonological), serial subtraction by seven (SS7; arithmetic), and reverse month recitation (RMR; sequential). DTC was calculated for eight gait parameters. Condition differences were assessed with nonparametric tests and post-hoc comparisons. Multiple linear regression, adjusting for age, sex, BMI, and baseline gait velocity, tested the independent association between MEQ score and mean velocity DTC; exploratory Spearman correlations examined other parameters. SS7 produced the largest mean velocity DTC (-12.76%), significantly greater than 5LWB (-7.95%; p = 0.002) and RMR (-9.57%; p = 0.021). MEQ score independently predicted mean velocity DTC in 5LWB ({beta} = -0.51, p < 0.001, R{superscript 2} = 0.269) and RMR ({beta} = -0.55, p = 0.004, R{superscript 2} = 0.222), indicating greater morningness associated with better gait-speed preservation under cognitive load; the SS7 association was not significant ({beta} = -0.33, p = 0.071). Exploratory correlations showed MEQ-DTC associations across 7/8 parameters in 5LWB, 4/8 in RMR, and 3/8 in SS7. Chronotype is independently associated with dual-task gait cost in a task-domain-specific manner, with stronger effects for phonological and sequential tasks than for arithmetic processing. The SS7 condition yielded the largest interference but weakest chronotype modulation, suggesting arithmetic dual-task disruption may be less sensitive to circadian arousal. Fixed testing time and cross-sectional design warrant within-subject, multi-timepoint studies to confirm chronotype effects separate from time-of-day confounds.

neuroscience↗

bioRxiv2026

Investigating the coupled effects of stiffness and stretch on the trabecular meshwork cells using a hydrogel-integrated microfluidic system

Glaucoma is characterized by progressive stiffening of the trabecular meshwork (TM), which elevates intraocular pressure and contributes to tissue dysfunction. Although substrate stiffness and mechanical stimulation both regulate TM homeostasis, their combined effects remain poorly understood. Here, a hydrogel-integrated microfluidic platform is presented that enables simultaneous control of substrate stiffness via tunable gelatin methacryloyl (GelMA) hydrogels and equi-biaxial quasi-static stretch via hydraulic actuation. Finite element analysis validates the applied strain field, and optimized crosslinking ensures structural stability. Primary normal TM (nTM) and glaucomatous TM (gTM) cells cultured under coupled conditions exhibit selective mechanotransduction dysregulation rather than global mechanosensory impairment. While nTM cells dynamically regulate -smooth muscle actin (-SMA), myocilin (MYOC), matrix metalloproteinase-2 (MMP2), and collagen type I (COL1), gTM cells display constitutively elevated -SMA, loss of mechanical regulation of MMP2, and impaired stretch-mediated COL1 suppression, while retaining stiffness-dependent focal adhesion kinase and MYOC sensitivity. Key differences between normal and glaucomatous cells emerge only under combined stiff and stretched conditions, underscoring the importance of coupled mechanical cues in revealing disease-relevant phenotypes. These findings implicate tissue stiffening in selective pathway dysregulation and highlight mechanotransduction-targeted therapeutic strategies.

bioengineering↗

bioRxiv2026

A Hierarchy-aware Gene Exploration Platform for Multi-layered Toxicogenomic Analysis: A Case Study on Acetaminophen-induced Hepatotoxicity

BackgroundThe interpretation of high-dimensional transcriptomic data remains a major challenge in mechanistic toxicology and drug safety assessment. Conventional clustering approaches based solely on expression profiles often fail to capture intrinsic biological relationships among genes, limiting interpretability and downstream analysis. MethodsWe developed a hierarchy-aware gene exploration platform that integrates structured biological knowledge from the HUGO Gene Nomenclature Committee (HGNC). The core of the framework is a similarity kernel based on a single-step hyperdiffusion formulation (HKH{top}), which embeds gene family hierarchy into the similarity space. The platform is implemented as an interactive web application supporting Uniform Manifold Approximation and Projection (UMAP) visualization, Leiden clustering, functional enrichment analysis, and hierarchy-based gene recommendation. ResultsApplied to a transcriptomic dataset of acetaminophen-induced acute liver failure (APAP-ALF), the proposed approach achieved a 33.8-fold improvement in functional coherence compared to an expression-only baseline. The hierarchy-aware embedding produced compact and biologically consistent clusters, enabling identification of key toxicological modules, including disruption of RNA processing, extracellular matrix remodeling, and impairment of lipid transport. In addition, the framework detected small but highly significant regulatory modules associated with epigenetic reprogramming. ConclusionBy incorporating biological hierarchy into gene similarity, the proposed platform enhances the interpretability of transcriptomic analysis and enables structured exploration of functional relationships. This approach provides a practical framework for mechanistic insight generation and supports more transparent and reproducible analysis in toxicogenomics. AvailabilityThe web application is freely available at https://hgncgeneexplorer.streamlit.app/.

bioinformatics↗

bioRxiv2026

The Common Fund Data Ecosystem (CFDE)

The NIH Common Fund Data Ecosystem (CFDE) integrates data resources from 18 NIH Common Fund programs for discovery and integrative analysis. These programs generate valuable but heterogeneous datasets that can be difficult to discover, access, and reuse. CFDE aims to provide a collaborative, community-built infrastructure that links and enriches Common Fund programs. We describe the evolution, structure, and core technologies of CFDE, including practical approaches that support submission, integration, visualization, and public release of multimodal data. Training programs and workforce initiatives lower barriers to adoption. CFDE has devised solutions to critical issues facing cross-program initiatives, including data scale and heterogeneity, dataset integration, and long-term sustainability. We demonstrate the utility of linking Common Fund resources through integrative tools and cross-dataset queries to yield insights that would otherwise be infeasible. Collectively, CFDE shows that a standards-driven, federated approach enhances and unifies cross-disciplinary resources, fostering collaboration and data-driven discovery.

scientific communication and education↗

bioRxiv2026

Optical Spectral Fingerprinting Enables Sensitive Detection of Anthracycline Chemotherapeutics in Synthetic Clinical Biofluids

Anthracycline chemotherapeutics are commonly used as frontline treatments for a wide array of cancers. However, their administration to patients results in substantial side effects, primarily cardiotoxicity, as well as myelosuppression and gastrointestinal toxicity. Current clinical management of such side effects is solely based on a lifetime dosage limit, which inhibits their anti-tumor efficacy. Many individualized factors, including age, family history of cardiovascular disease, treatment regimen, and other co-morbidities influence drug pharmacology. Despite this heterogeneity, there is no method for determining actual organ or tumor exposure to the treatment in an individual. Here, we developed an optical nanosensor array for four anthracyclines--doxorubicin, daunorubicin, epirubicin, and idarubicin. We used single-walled carbon nanotubes as the signal transducer due to their tunable near-infrared fluorescence. We screened twelve distinct ssDNA sequences paired with seven SWCNT (n,m) species at increasing concentrations of each of the four anthracyclines. The spectral responses were then used to develop machine learning-based classification models to identify different anthracycline types and concentrations. The optimized extreme gradient boosting model was able to classify high levels of each anthracycline with 100% accuracy. Concentration-based classification by PCA was performed for each anthracycline, distinguishing low ([≤] 5 {micro}M) and high (> 5 {micro}M) concentrations. Finally, we validated the sensor performance using synthetic urine and sweat. Our findings demonstrate the potential of carbon nanotube-based sensor array to measure the pharmacokinetics of anthracyclines in patients with the goal of enhancing anti-tumor efficacy and monitoring off-target toxicities.

bioengineering↗

bioRxiv2026

A multi-omic atlas in the African turquoise killifish reveals increased glucocorticoid signaling as a hallmark of brain aging

Aging is the leading risk factor for cognitive impairment and neurodegeneration, yet molecular changes that unfold in the brain over time, and how they drive this vulnerability, remain unclear. The naturally short-lived African turquoise killifish (Nothobranchius furzeri) offers a powerful model to understand brain aging on an accelerated timescale and test the impact of potential interventions. Here, we present a multi-omic atlas of brain aging of female and male African turquoise killifish from 2 independent genetic strains of different captive lifespans, encompassing single-nuclei RNA-seq, single nuclei ATAC-seq, and bulk ATAC-seq to capture transcriptional and regulatory changes. Interestingly, our atlas indicates that aging leads to a significant expansion of microglia numbers, regardless of sex or strain, which we independently validate using in-situ hybridization. In addition, we identify robust and conserved gene regulation changes, that are consistent with activation of glucocorticoid signalling as a hallmark (and potential driver) of vertebrate brain aging. Furthermore, pharmacological inhibition of glucocorticoid receptor activity starting at middle-age led to significant rescue of key molecular and cellular aging phenotypes. Thus, our study provides a powerful resource and framework to leverage the African turquoise killifish and rapidly uncover actionable pathways driving brain aging.

neuroscience↗

bioRxiv2026

Module-selection balance in the evolution of modular organisms

The architecture of the genotype-phenotype-fitness map (GPFM) is a key determinant of evolutionary dynamics. One salient feature of biological GPFMs is variational modularity, where each mutation affects only a small subset of functional traits. Variational modularity may constrain the dynamics of trait evolution, but these constraints are not well understood. Here, we use several extensions of the Fishers geometric model with two functional traits to investigate these constrains. We find that on GPFMs with universal pleiotropy, populations evolve along the fitness gradient, which implies that the trait under stronger selection is optimized exponentially faster than the trait under weaker selection. In contrast, on modular GPFMs, populations approach a quasi-steady state that we term a "module-selection balance" where both traits improve at the same rate and their ratio remains constant. We demonstrate that the existence of a module-selection balance is robust with respect to the details of evolutionary dynamics and GPFMs themselves, as long as they are variationally modular. Our theory predicts that variationally modular organisms should exhibit stereotypical bi-phasic dynamics of genome evolution, especially in the strong clonal interference regime, and we find support for this prediction in metagenomic data from Lenskis long-term evolution experiment in bacterium Escherichia coli. We propose that module-selection balance is an inherent feature of variationally modular GPFMs, which imposes an important constraint on long-term trait evolution.

evolutionary biology↗

bioRxiv2026

Cultivation and genomic characterization of the first representative of the globally distributed marine UBA868 group

Members of the UBA868 group within the order Arenicellales are globally distributed marine Gammaproteobacteria predicted to participate in sulfur and carbon cycling, yet their physiology and ecological roles remain unknown due to the absence of cultured representatives. Here, we report the isolation and characterization of the first heterotrophic representative of the previously uncultured UBA868 group. Using dilution-to-extinction cultivation, we obtained four isolates from the Yellow Sea whose high-quality genomes represent a single UBA868 species. One strain, IMCC57338, maintained in axenic culture, exhibited small coccoid morphology and slow growth (doubling time [~]2.9 days), consistent with an oligotrophic lifestyle. Genome analysis revealed a predominantly aerobic chemoorganoheterotrophic lifestyle with a streamlined central carbon metabolism, including a complete glyoxylate shunt and limited carbohydrate utilization capacity, suggesting adaptation to low-nutrient conditions. The genome also encodes pathways for methylated amine oxidation coupled to formaldehyde assimilation via the serine cycle, indicating a capacity for methylotrophy. Genes encoding sulfur oxidation (Sox) and reverse dissimilatory sulfite reductase (rDsr) pathways further suggest a capacity for sulfur-based chemolithoheterotrophy. Global metagenomic and metatranscriptomic read recruitment showed that the species represented by IMCC57338 is widely distributed across ocean basins and pelagic depth layers, with higher abundance and transcriptional activity in mesopelagic waters. Our findings provide the first physiological and genomic insights into the UBA868 group and suggest that members of this lineage contribute to the cycling of organic carbon, C1 compounds, and sulfur in marine ecosystems.

microbiology↗

bioRxiv2026

Retrosplenial cortex vulnerability links severe hypoglycemia to cognitive impairment through neuron-microglia crosstalk

Severe hypoglycemia remains a serious adverse effect of insulin therapy in individuals with diabetes and is linked to cognitive decline, yet the mechanisms by which transient metabolic stress leads to persistent neuronal dysfunction remain poorly defined. Using mouse models of acute severe hypoglycemia and integrated screening, we identified the retrosplenial cortex as a previously unrecognized brain region that is particularly vulnerable to hypoglycemia-induced neuronal damage. This injury is driven by a feedforward interaction between neuron-specific Drp1-dependent mitochondrial fission and microglial IL-1 signaling, as pharmacological or genetic targeting of either pathway suppressed the other, rescued neuronal damage, and reversed cognitive impairment. These findings identify a region-specific neuron-microglia injury circuit that links severe hypoglycemia to cognitive dysfunction and suggest a therapeutic strategy to protect brain function without compromising diabetes management.

neuroscience↗

bioRxiv2026

Spatial polarization of endothelial ICAM-1 governs T-cell exclusion in melanoma

An immunosuppressive tumor microenvironment limits therapeutic efficacy and worsens prognosis in melanoma. Beyond T-cell abundance and function, effective tumor control also depends on whether T cells can access malignant cells within the tumor. Although emerging evidence supports that tumor vasculature facilitates immune evasion, the vascular mechanisms that govern intratumoral T-cell positioning remain poorly defined. Using RNA sequencing of endothelial cells isolated from tumor cores versus peripheries in a mouse melanoma model, we identified intercellular adhesion molecule 1 (ICAM-1) as a candidate regulator of T-cell localization. During tumor growth, T cells shifted from a balanced core-margin distribution to marked exclusion from the core, most prominently in T cell-inflamed tumors. This spatial redistribution --less evident in other immune subsets--coincided with high expression of lymphocyte function-associated antigen-1 (LFA-1) on T cells. In parallel, endothelial ICAM-1 became enriched at the tumor periphery, where vascular integrity was compromised, as evidenced by increased vascular leakage and reduced pericyte coverage. Functionally, ICAM-1 blockade restored intratumoral T-cell infiltration, enhanced effector activity, and significantly delayed the growth of immunogenic tumors. Moreover, ICAM-1 inhibition sensitized an immune-refractory tumor to anti-PD-1 checkpoint blockade. Together, these findings identify endothelial ICAM-1 as a vascular determinant of intratumoral T-cell positioning and highlight the ICAM-1/LFA-1 axis as a modifiable checkpoint to reverse T-cell retention at the tumor periphery, thereby enhancing antitumor immunity and immunotherapy efficacy.

cancer biology↗

bioRxiv2026

CellPheno: A High-throughput Computational Platform for Quantifying Cellular Resolution Whole Brain Microscopy Images

Advances in tissue clearing and light-sheet microscopy enable cellular resolution whole-brain 3D imaging. However, whole-brain quantification tools do not yet meet demands for efficiency or assess morphometry. Here we present CellPheno, a 3D nuclei instance segmentation framework for high-throughput cellular phenotyping. CellPheno quantifies an entire P4 mouse brain within 15 hours. We showcase whole-brain morphometry, enhanced stitching, and co-localization across multiple cell types in 53 brains.

neuroscience↗

bioRxiv2026

Circulating miR-10b-5p drives Kawasaki vasculitis through endothelial reprogramming and nominates CXCL8 as an early diagnostic biomarker

BackgroundKawasaki disease (KD) is an acute systemic vasculitis of unknown etiology and the leading cause of acquired heart disease in children. Coronary artery aneurysm formation represents its most serious complication, yet no specific biomarker exists for early diagnosis at emergency department (ED) presentation. We sought to define the molecular mechanisms driving KD vasculitis and to identify a clinically actionable early diagnostic marker. MethodsWhole microRNA sequencing was performed on buffy coat specimens from KD patients and febrile controls presenting to the ED. Disease-associated miRNA candidates were validated in two independent murine KD-like vasculitis models: Lactobacillus casei cell wall extract (LCWE; n=12-20) and Candida albicans water-soluble fraction (CAWS; n=12). The functional role of miR-10b-5p was assessed by antagomir-mediated inhibition in the LCWE model. Transcriptomic and chromatin-level reprogramming were characterized by single-cell RNA sequencing (scRNA-seq), bulk RNA-seq, and assay for transposase-accessible chromatin with sequencing (ATAC-seq) in human coronary artery endothelial cells (HCAECs). Transcription factor binding was validated by in vitro binding assays and chromatin immunoprecipitation. Serum chemokine (C-X-C motif) ligand 8 (CXCL8) was quantified by enzyme-linked immunosorbent assay. ResultsForty miRNAs were upregulated in KD patients and fourteen miRNAs were prioritized for further analysis. miR-10b-5p was consistently elevated across both vasculitis models, and its antagomir-mediated inhibition attenuated aortic root inflammation in vivo. In HCAECs, miR-10b-5p suppressed its direct targets marker of proliferation Ki-67 (MKI67)/Chromobox5 (CBX5), driving a cell-state transition from proliferative/metabolic programs toward a pro-inflammatory phenotype. Consistently, analyses of bulk RNA-seq supported cell-cycle arrest and altered chromatin remodeling. ATAC-seq revealed increased chromatin accessibility at the CXCL8 and Matrix metalloproteinases 10 (MMP10) promoters, and motif analysis identified CCAAT/enhancer-binding protein alpha (CEBPA) as the key transcriptional activator; CEBPA knockdown abrogated miR-10b-5p-induced CXCL8 and MMP10 upregulation. Serum CXCL8 was markedly elevated in KD patients relative to febrile controls at first ED presentation, prior to definitive diagnosis, and declined significantly at 8-week follow-up. ConclusionsWe define a miR-10b-5p-MKI67/CBX5-CEBPA-CXCL8 axis as a mechanistic driver of endothelial reprogramming and neutrophil-recruiting inflammation in KD. Serum CXCL8 emerges as a candidate early diagnostic biomarker that may facilitate timely KD recognition at ED presentation.

molecular biology↗

bioRxiv2026

3D chromatin compartment of round spermatids encodes the spatiotemporal program of histone-to-protamine exchange in spermiogenesis

Sperm formation requires a radical chromatin reorganization, where nucleosomes are replaced by transition proteins (TNPs) and subsequently by protamines (PRM1 and PRM2). Although essential for fertility, the regulatory logic governing this exchange is unknown, but its presumed to be stochastic and unregulated. Using endogenously tagged PRM mouse models and stage-resolved, genome-wide profiling, we revise the order of histone-to-protamine exchange and show that the chromatin remodeling process is highly programmed. Imaging and biochemical experiments reveal a direct histone-to-PRM1 exchange, while TNPs appear after PRM1 but precede PRM2 incorporation. This temporal uncoupling of PRM1 and PRM2 incorporation coincides with dynamic, region-specific chromatin remodeling that is not governed by histone acetylation but is instructed by the three-dimensional nuclear architecture of round spermatids. Therefore, by integrating ATAC-seq, CUT&Tag, and Hi-C, we define a compartment-encoded "blueprint" that prescribes the assembly of the mature sperm epigenome and establishes a complex molecular hierarchy for the histone-to-protamine exchange.

genomics↗