Biology subjects

Liao, Y.

Publications and source records attributed to Liao, Y..

At least 55 records · Page 3Linked to original sources

bioRxiv2025

CD45-mediated apoptosis and IL2R downregulation by serine proteases from diarrheagenic bacteria

Most enteropathogens secrete one or more members of the serine protease autotransporters of Enterobacteriaceae (SPATE). We previously demonstrated that SPATE cleaves various O-linked glycoproteins on leukocytes, including the tyrosine phosphatase CD45RO. SPATE impairs leukocyte functions and triggers apoptosis in activated T cells in vitro. Here, we show that SPATE produced by pathogenic E. coli, Shigella, and the mouse pathogen Citrobacter rodentium cleaves not only CD45RO but also CD45 isoforms containing exons A and B. We found that the cleavage of CD45 in primary T cells from both human and murine sources correlated with decreased IL2RA (CD25) surface expression in a concentration-dependent manner. SPATE did not cleave CD25 or affect T cell activation. However, SPATE requires CD45 expression for the depletion of CD25 in activated T cells, as SPATE did not significantly impact CD25 in the Jurkat J45.01 cell line, which lacks CD45. More importantly, we discovered that J45.01 cells resisted SPATE-mediated apoptosis, whereas apoptotic wild-type Jurkat cells exhibited decreased surface expression of CD25. Furthermore, we observed that mice infected with C. rodentium lacking SPATE displayed lower mortality, delayed intestinal colonization, reduced inflammatory cytokines, and decreased leukocyte infiltration in the lamina propria while having a higher number of CD25+ T cells compared to mice infected with wild-type CR or the CR SPATE mutant expressing Crc2 in trans. Our data suggest that SPATE-producing pathogens trigger T-cell apoptosis through CD45 via a mechanism akin to IL2 deprivation, demonstrating that SPATE can act as immunomodulators at various levels of the immune system. SIGNIFICANCEWe have demonstrated for the first time that serine proteases (C2S) from clinically relevant pathogens, such as E. coli pathotypes and Shigella, can cleave leukocyte glycoproteins, including the tyrosine phosphatase CD45, which play crucial roles in cellular and immune functions. In this study, we discovered that C2S induces apoptosis in activated T cells through a previously unknown mechanism resembling IL-2 deprivation, mediated by CD45. Furthermore, we found that C2S is essential for bacterial virulence in vivo. This suggests that pathogens producing C2S may possess previously undescribed immunoregulatory functions that enhance their survival in the host and contribute to the disease process by eliminating T cells through the targeting of CD45 and the IL-2 receptor.

microbiology↗

bioRxiv2025

Accelerated genome shuffling associated with rapid evolution of sexual conflict in seed beetles

Structural variation (SV) has an extensive impact on the evolution of the genome. The diverse SV provide a material basis for genome evolution, which can affect gene expression, 3D genome structure, and even changes in complex chromosomal features through regional recombination, copy number variation, and chromosome rearrangement. Here, we assemble and compare the chromosome-level assemblies of three species (Acanthoscelides obtectus, Callosobruchus chinensis, and C. maculatus) in Bruchinae, a clade of Coleoptera that is often used as models to study sexual conflict, to investigate the influence of SV on the changes of various genomic characteristics during species evolution. Through comparative genomic analysis of Coleoptera species, we reveal extensive structural variants (SVs) within the Bruchinae family, which is linked to the ongoing activity of LINE transposons. We show that SV drive the rapid evolution of sex chromosomes and correlated with dynamic evolution of sex-biased gene expression in seed beetle species. Our analysis highlights the acquisition of novel genes on the Y chromosome through frequent gene translocations, gradually shaping them into genes exhibiting male-biased expression patterns. This underscores the Y chromosomes role in promoting sexual dimorphism evolution. Our findings reveal the significant contributions of SV to genome evolution, specifically through their influence on sex chromosome evolution and the evolutionary dynamics of sex-biased genes.

evolutionary biology↗

bioRxiv2025

Spatial Total RNA Sequencing of Formalin-Fixed Paraffin Embedded Tissues by spRandom-seq

Current oligo(dT) primers-based spatial transcriptomic methods are limited to fresh or fresh-frozen samples due to the low efficiency of oligo(dT) primers in capturing RNAs in degraded or microbial samples. Here, we have developed a random primer-based spatial total RNA sequencing (spRandom-seq) technology for simultaneously capturing whole host and microbial RNAs in formalin-fixed paraffin-embedded (FFPE) tissues. spRandom-seq eliminated 3 or 5 gene-body biases and outperformed oligo(dT)-based 10X Visium with an 8-fold higher capturing rate for lncRNA and other non-polyadenylated RNA biotypes, including miRNA, snRNA and miscRNA. In the clinical FFPE sections of breast cancer, we revealed the inherent heterogeneity within the tumor region. We also simultaneously captured host and microbial RNAs in Klebsiella pneumoniae-infected sections. Totally, spRandom-seq provided a versatile tool for both clinical pathology and infection biology with established spatial platforms, ensuring ease of operation and large-scale applications.

genomics↗

bioRxiv2025

POCALI: Prediction and insight On CAncer LncRNAs by Integrating multi-omics data with machine learning

Long non-coding RNAs (lncRNAs) are receiving increasing attention as biomarkers for cancer diagnosis and therapy. Although there are many computational methods to identify cancer lncRNAs, they do not comprehensively integrate multi-omics features for predictions or systematically evaluate the contribution of each omics to the multifaceted landscape of cancer lncRNAs. In this study, we developed an algorithm, POCALI, to identify cancer lncRNAs by integrating 44 omics features across six categories. We explored the contributions of different omics to identifying cancer lncRNAs and, more specifically, how each feature contributes to a single prediction. We also evaluated our model and benchmarked POCALI with existing methods. Finally, we validated the cancer phenotype and genomics characteristics of the predicted novel cancer lncRNAs. POCALI identified secondary structure and gene expression-related features as strong predictors of cancer lncRNAs, and epigenomic features as moderate predictors. POCALI performed better than other methods, especially in terms of sensitivity, and predicted more candidates. Novel POCALI-predicted cancer lncRNAs had strong relationships with cancer phenotypes, similar to known cancer lncRNAs. Overall, this study facilitated the identification of previously undetected cancer lncRNAs and the comprehensive exploration of the multifaceted feature contributions to cancer lncRNA prediction.

bioinformatics↗

bioRxiv2025

Infectome Analysis of Small Mammals in Southern China Reveals Ecological Associations and Emerging Threats from Diverse Pathogens

Small mammals harbor a diverse array of zoonotic pathogens. To date, however, metagenomic surveys of these species have primarily focused on viral diversity, with limited attention paid to bacteria and eukaryotic pathogens. Additionally, the ecological determinants of pathogen diversity within these mammals have not been systematically examined. Herein, we employed a metatranscriptomics approach to survey the pathogen infectome of 2,408 individual samples, representing lung, liver, and gut tissues from 858 animals collected throughout Guangdong province, China, with a study design that accounted for host species, tissue, season, and geographic location. We identified 76 pathogen species, including 29 RNA viruses, 12 DNA viruses, 5 bacteria, and 30 eukaryotic pathogens, 33 of which were newly discovered. Tissue distribution analysis revealed distinct organotropisms, suggesting varied transmission routes, while host distribution analysis showed that each animal carried an average of one pathogen, with 10 pathogens widely distributed among mammalian orders. Our characterization of the geographic and seasonal patterns revealed that pathogen richness was primarily influenced by region, host species, and season, while pathogen composition was largely shaped by host genetic distance. Collectively, these data provide the first comprehensive insight into the dynamics of the pathogen infectome in these key mammalian disease reservoirs, highlighting the major factors driving pathogen diversity and transmission.

microbiology↗

bioRxiv2025

DAZAP2 functions as a pan-coronavirus restriction factor by inhibiting viral entry and genomic replication

The SARS-CoV-2 pandemic and the emergence of novel variants underscore the need to understand host-virus interactions and identify host factors that restrict viral infection. Here, we perform a genome-wide CRISPR knockout screen to identify host restriction factors for SARS-CoV-2, revealing DAZAP2 as a potent antiviral gene. DAZAP2, previously implicated in SARS-CoV-2 restriction, is found to inhibit viral entry by blocking virion fusion with both endolysosomal and plasma membranes. Additionally, DAZAP2 suppresses genomic RNA replication without affecting the primary translation of viral replicases. We demonstrate that DAZAP2 functions as a pan-coronavirus restriction factor across four genera of coronaviruses. Importantly, knockout of DAZAP2 enhances SARS-CoV-2 infection in mouse models and in human primary airway epithelial cells, confirming its physiological relevance. Mechanistically, antiviral activity of DAZAP2 appears to be indirect, potentially through the regulation of host gene expression, as it primarily localizes to the nucleus. Our findings provide new insights into the host defense system against coronaviruses and highlight DAZAP2 as a potential target for host-directed antiviral therapies. IMPORTANCEDuring viral infection, the host defense response is mediated by a variety of host factors through distinct mechanisms that have yet to be fully elucidated. Although DAZAP2 was previously implicated in SARS-CoV-2 restriction, its mechanisms of action and in vivo relevance remain unclear. In this study, we identify the DAZAP2 as a potent pan-coronavirus restriction factor that inhibits viral infection through dual mechanisms: blocking virion fusion with both endolysosomal and plasma membranes, and suppressing genomic RNA replication. We confirm its physiological relevance in host defense using mouse models and primary cell cultures. This study advances our understanding of host-pathogen interactions. Targeting DAZAP2 or its regulatory pathways could provide a new approach to enhance host defense against current and future coronavirus threats.

microbiology↗

bioRxiv2025

Optogenetic control of Protein Kinase C-epsilon activity reveals its intrinsic signaling properties with spatiotemporal resolution

The regulation of PKC epsilon (PKC{varepsilon}) and its downstream effects is still not fully understood, making it challenging to develop targeted therapies or interventions. A more precise tool that enables spatiotemporal control of PKC{varepsilon} activity is thus required. Here, we describe a photo-activatable optogenetic PKC{varepsilon} probe (Opto-PKC{varepsilon}) consisting of an engineered PKC{varepsilon} catalytic domain and a blue-light inducible dimerization domain. Molecular dynamics and AlphaFold simulations enable rationalization of the dark-light activity of the optogenetic probe. We first characterize the binding partners of Opto-PKC{varepsilon}, which are similar to those of PKC{varepsilon}. Subsequent validation of the Opto-PKC{varepsilon} tool is performed with phosphoproteome analysis, which reveals that only PKC{varepsilon} substrates are phosphorylated upon light activation. Opto-PKC{varepsilon} could be engineered for recruitment to specific subcellular locations. Activation of Opto-PKC{varepsilon} in isolated hepatocytes reveals its sustained activation at the plasma membrane is required for its phosphorylation of the insulin receptor at Thr1160. In addition, Opto-PKC{varepsilon} recruitment to the mitochondria results in its lowering of the spare respiratory capacity through phosphorylation of complex I NDUFS4. These results demonstrate that Opto-PKC{varepsilon} may have broad applications for the studies of PKC{varepsilon} signaling with high specificity and spatiotemporal resolution. SummaryWe have developed a photo-activatable optogenetic PKC{varepsilon} probe, which demonstrates differential activity in light versus dark. The tool is subsequently validated with protein association studies and phosphoproteome analysis. It enables dissection of signaling events arising from its activation at defined subcellular locations. For instance, sustained activation of PKC{varepsilon} at the plasma membrane is required for its phosphorylation of the insulin receptor at Thr1160.

molecular biology↗

bioRxiv2025

Synergizing Network Pharmacology and Pan-Cancer Analysis in TCM Repositioning for Tumor Therapy

BackgroundRepositioning Traditional Chinese Medicine (TCM) for cancer treatment, addressing heterogeneity through synergistic effects, aligns with the evolving trend of combination therapy. However, the complexity of TCM and the lack of methodology hinders the elucidation of TCM treatment mechanisms and potential indications. The research aims to construct develop a comprehensive method combining network pharmacology and pan-cancer analysis (NetPharm-PanCan) for TCM repositioning, exemplified by the Astragali Radix-Curcumae Rhizoma (ARCR) herb pair. MethodThe TCM-component-gene network was constructed using Cytoscape3.7.2 with gene screening based on components from TCMSP and targets predicted via the Swiss Target Prediction database. The core gene set of the ARCR (CGSARCR) was identified by analyzing network via the dual algorithm, namely Degree and MCODE followed by GO and KEGG enrichment analyses. The pan-cancer analysis encompassing Gene Set Variation Analysis (GSVA), immune infiltration correlation, cancer pathway analysis, and Gene Set Enrichment Analysis (GSEA) was unveiled to identify the potential indications. Multivariate cox regression analysis was employed for identifying prognostic genes, followed by the modeling for potential therapeutic indications using the R software. The Metescape database was harnessed to reveal similarities and differences in the mechanisms for prognostic genes associated with potential indications. The XGBoost algorithm was used to construct an indication prediction system according to the analysis results above. ResultThe CGSARCR comprises 28 genes targeting all ARCR components. The pan-cancer analysis revealed that the CGSARCR showed significantly higher tumor scores than normal tissue scores across nine different types of cancer, including THCA, KIRC, LUAD, COAD, BRCA, STAD, ESCA, and others. The CGSARCR correlated strongly with cancer-related pathways and the immune microenvironment. Prognostic models evaluate the potential of these indications as follows: THCA> KIRC> LUAD> COAD> BRCA> STAD> ESCA, with enrichment analysis suggesting KIRC and LUAD as the most potential indications of ARCR. The XGBoost-based system achieved high predictive accuracy (training AUC: 0.985, testing AUC: 0.96, training logloss: 0.21, testing logloss: 0.25). ConclusionThe NetPharm-PanCan method provides a robust, network-based pan-cancer analysis framework for TCM repositioning in cancer research. It provides theoretical foundations and practical tools for TCM-based drug development, with potential applicability to broader drug repurposing efforts.

bioinformatics↗

bioRxiv2024

Patient-Derived Xenografts of Triple-Negative Breast Cancer Enable Deconvolution and Prediction of Chemotherapy Responses

Chemotherapy regimens for triple-negative breast cancer (TNBC) combine agents without knowing which agents drive response. Consequently, predictors derived from multi-agent regimens cannot be assumed to generalize to individual drugs or other regimens, motivating development of treatment-matched predictors. Here, we used TNBC patient-derived xenografts (PDXs) treated with carboplatin, docetaxel, or the combination to deconvolute drug-specific responses and identify associated molecular features. Combination treatment rarely improved upon the best single agent, with enhanced responses in only 13% of PDXs and antagonism in a comparable fraction. Proteogenomic analyses identified high cytokeratin-5 (KRT5) as a general marker of chemotherapy responsiveness and KRT5 immunohistochemistry discriminated responsive PDXs (AUROC, 0.83). To train treatment-specific predictors, we integrated these data with independent PDX and clinical cohorts with responses assessed after anthracycline-free platinum, taxane, or platinum-taxane therapy, ensuring response corresponded to the modeled treatment. Four feature selection strategies yielded largely nonoverlapping biomarker panels converging on treatment-relevant pathways. On independent test data, RNA-based predictors of complete response (CR) to platinum-based (carboplatin or cisplatin) and taxane-based (docetaxel or paclitaxel) chemotherapy achieved AUROCs of 0.80 and 0.86, respectively. For platinum-taxane regimens (carboplatin plus docetaxel or paclitaxel), proteomic-guided feature selection generated a 10-biomarker, protein- informed RNA predictor of pathologic complete response (pCR) that outperformed RNA-only feature selection and achieved an AUROC of 0.85 in an independent clinical cohort, while retaining practicality as an RNA-based assay. Treatment-matched integration of multi-omic PDX and clinical datasets provides a framework for chemotherapy-specific predictors with clinically relevant performance, supporting biomarker-guided precision selection and treatment optimization for patients with TNBC. Statement of significanceIntegration of multi-omic data from patient-derived xenografts with treatment-matched clinical cohorts yielded three retrospectively validated predictors of platinum, taxane, and platinum+taxane response, enabling biomarker-guided chemotherapy selection for patients with triple-negative breast cancer.

cancer biology↗

bioRxiv2024

Magnetically induced magnetosome chain (MAGiC):A biogenic magnetic-particle-imaging tracer with high performance and navigability

Magnetic particle imaging (MPI) enables real-time, sensitive and quantitative visualization of magnetic tracers spatial distribution, augmenting the capability of in vivo imaging technologies. Previous tracer studies in MPI have primarily focused on superparamagnetic nanoparticles; however, their non-ideal sigmoidal magnetization response limits the spatial resolution. Here we demonstrate the utilization of magnetically induced magnetosome chain (MAGiC) as a novel superferromagnetic MPI tracer, exhibiting a 25-fold improvement in resolution and a 91-fold enhancement in signal intensity compared to the commercial tracer VivoTrax+. The spatial resolution of MPI was pushed to an unprecedented 80 m under a 4 T/m gradient field. Additionally, MAGiC can be precisely controlled using magnetic fields, enabling it to function as a MPI trackable microrobot. We provided a theoretical model elucidating MAGiCs unique properties, and validated its imaging and actuation performance through phantom studies and in vivo experiments. As a high-performance MPI tracer and magnetic microrobot with exceptional capabilities, MAGiC holds tremendous potential for diverse applications including cell tracking, targeted drug delivery as well as therapeutic interventions.

bioengineering↗

bioRxiv2024

Annulate Lamellae biogenesis is essential for nuclear pore function

Nuclear pore complexes (NPCs) enable nucleocytoplasmic transport. While NPCs primarily localize to the nuclear envelope (NE), they also appear in cytoplasmic endoplasmic reticulum (ER) membranes called annulate lamellae (AL). Though discovered in the mid-20th century, ALs function and biogenesis remain unclear. Previously considered exclusive to embryonic and malignant cells, we find AL in somatic mammalian cells. Under normal conditions, AL store pre-assembled NPCs (AL-NPCs) that integrate into the NE during G1 to support nuclear expansion. Upon pathological stimuli, AL transfer to the NE is impaired, leading to their cytoplasmic accumulation. RanBP2 (Nup358) is essential for AL biogenesis, with its phenylalanine-glycine (FG) repeats promoting AL-NPC scaffold oligomerization. ER-associated Climp63 (CKAP4) directs AL-NPCs to ER sheets and the NE. This AL-driven nuclear pore formation is complementary to the canonical routes, constituting a distinct NPC assembly pathway. Our work uncovers the biogenesis mechanism of AL and the nuclear function of this key cellular organelle.

cell biology↗

bioRxiv2024

Climate Adaptation and Genetic Differentiation in the Mosquito Species Culex tarsalis

The increasing prevalence of vector-borne diseases around the world highlights the pressing need for an in-depth exploration of the genetic and environmental factors that shape the adaptability and widespread distribution of mosquito populations. This research focuses on Culex tarsalis, a principal vector for various viral diseases including West Nile Virus (WNV). Through the development of a new reference genome and the examination of Restriction-Site Associated DNA sequencing (RAD-seq) data from over 300 individuals and 28 locations, we demonstrate that variables such as temperature, evaporation rates, and the density of vegetation significantly impact the genetic makeup of Cx. tarsalis populations. Among the alleles most strongly associated with environmental factors is a nonsynonymous mutation in a key gene related to circadian rhythms. These results offer new insights into the mechanisms of spread and adaptation in a key North American vector species, which is poised to become a growing health threat to both humans and animals in the face of ongoing climate change.

genomics↗

bioRxiv2024

Modulating DNA Polα Enhances Cell Reprogramming Across Species

As a fundamental biological process, DNA replication ensures the accurate copying of genetic information. However, the impact of this process on cellular plasticity in multicellular organisms remains elusive. Here, we find that reducing the level or activity of a replication component, DNA Polymerase (Pol), facilitates cell reprogramming in diverse stem cell systems across species. In Drosophila male and female germline stem cell lineages, reducing Pol levels using heterozygotes significantly enhances fertility of both sexes, promoting reproductivity during aging without compromising their longevity. Consistently, in C. elegans the pola heterozygous hermaphrodites exhibit increased fertility without a reduction in lifespan, suggesting that this phenomenon is conserved. Moreover, in male germline and female intestinal stem cell lineages of Drosophila, pol heterozygotes exhibit increased resistance to tissue damage caused by genetic ablation or pathogen infection, leading to enhanced regeneration and improved survival during post-injury recovery, respectively. Additionally, fine tuning of an inhibitor to modulate Pol activity significantly enhances the efficiency of reprogramming human embryonic fibroblasts into induced pluripotent cells. Together, these findings unveil novel roles of a DNA replication component in regulating cellular reprogramming potential, and thus hold promise for promoting tissue health, facilitating post-injury rehabilitation, and enhancing healthspan.

developmental biology↗

bioRxiv2024

Transcriptomic alterations including p53 pathway dysregulation prime DNMT3A mutant cells for transformation

DNMT3A mutations are prevalent in haematologic malignancies. Our mouse model introduced the murine homologue (R878H) of the human hotspot R882H mutation into the mouse Dnmt3a locus, resulting in globally reduced DNA methylation in all tissues. Mice with heterozygous R878H mutations developed {gamma}-radiation induced thymic lymphoma more rapidly than control mice, suggesting a vulnerability to stress stimuli in Dnmt3aR878H/+ cells. In competitive transplantations, Dnmt3aR878H/+ Lin-Sca-1+Kit+ (LSK) cells had a competitive advantage over wt cells, indicating a self-renewal phenotype at the expense of differentiation. RNA-sequencing of Dnmt3aR878H/+ LSKs exposed to low dose {gamma}-radiation showed downregulation of the p53 pathway. Accordingly, reduced PUMA expression was observed by flow cytometry in the bone marrow of {gamma}-irradiated Dnmt3aR878H/+ mice due to altered p53 signalling. These findings provide new insights as to how DNMT3A mutations cause subtle changes in the transcriptome of LSK cells which contribute to their increased self-renewal and propensity for malignant transformation. SIGNIFICANCEHotspot DNMT3A R882H mutations are overrepresented in leukaemia suggesting that they confer a susceptibility to disease if further mutations are acquired. To advance therapies for DNMT3A mutant disease, it is essential to understand the mechanisms by which this mutation primes cells for malignant transformation.

cancer biology↗

bioRxiv2024

Genome structural variants shape adaptive success of an invasive urban malaria vector Anopheles stephensi

Global changes are associated with the emergence of several invasive species. However, the genomic determinants of the adaptive success of an invasive species in a new environment remain poorly understood. Genomic structural variants (SVs), consisting of copy number variants, play an important role in adaptation. SVs often cause large adaptive shifts in ecologically important traits, which makes SVs compelling candidates for driving rapid adaptations to environmental changes, which is critical to invasive success. To address this problem, we investigated the role SVs play in the adaptive success of Anopheles stephensi, a primary vector of urban malaria in South Asia and an invasive malaria vector in several South Asian islands and Africa. We collected whole genome sequencing data from 115 mosquitoes from invasive island populations and four locations from mainland India, an ancestral range for the species. We identified 2,988 duplication copy number variants and 16,038 deletions in these strains, with [~]50% overlapping genes. SVs are enriched in genomic regions with signatures of selective sweeps in the mainland and invasive island populations, implying a putative adaptive role of SVs. Nearly all high-frequency SVs, including the candidate adaptive variants, in the invasive island populations are present on the mainland, suggesting a major contribution of existing variation to the success of the island populations. Among the candidate adaptive SVs, three duplications involving toxin-resistance genes evolved, likely due to the widespread application of insecticides in India since the 1950s. We also identify two SVs associated with the adaptation of An. stephensi larvae to brackish water in the island and two coastal mainland populations, where the mutations likely originated. Our results suggest that existing SVs play a vital role in the evolutionary success of An. stephensi in new environmental conditions.

evolutionary biology↗

bioRxiv2024

FLASH radiotherapy using high-energy X-rays: validation of the FLASH effect triggered by a compact single high-energy X-ray source device

PurposeThis preclinical study aimed to verify the FLASH effect of compact single high-energy X-ray source (CHEXs) and to explore whether three irradiations with single-gantry rotation two 30 s pauses can generate FLASH effect in mice. Materials and methodsThe absolute dose and pulsed beam of the CHEXs were measured using an EBTXD radiochromic film and fast current transformer. Healthy C57BL/6J female mice and a subcutaneous tumor model were irradiated under different conditions: sham (control), FLASH-RT (FLASH1: delivering the total dose in 1 fraction; FLASH3: delivering the total dose with two 30 second pauses to simulate a three-field delivery where the gantry rotation is occurring within 30 seconds), and conventional dose rate radiotherapy (CONV-RT). Various total doses were administered to the corresponding normal tissues (whole thorax, 30 Gy; whole abdomen, 12 Gy; and skin, 36 Gy) and tumors (CT26, 16.5 Gy; and LLC, 18 Gy). Survival status, normal tissue damage, and tumor growth suppression were recorded in each group. ResultsThe average dose rate of the CHEXs exceeded 40 Gy/s. For whole-thorax and skin irradiation, both FLASH1 and FLASH3 demonstrated protective effects. For whole-abdomen irradiation, FLASH1 exhibited a superior protective effect. No significant differences in tumor growth responses were observed between the FLASH1, FLASH3, and CONV-RT groups (P>0.05). ConclusionThis study confirmed that the FLASH effect could be triggered using CHEXs FLASH radiotherapy, and demonstrated that three irradiations with single gantry rotation two 30 s pauses can trigger the FLASH effect, indicating the potential benefit of CHEXs 3D conformal radiotherapy. Our findings indicate that further clinical trials on CHEXs are warranted.

cancer biology↗

bioRxiv2024

Cell division protein A (CdpA) assembles and anchors the two FtsZ rings at midcell in haloarchaea

Many archaea appear to divide through the coordinated activities of two FtsZ homologues (FtsZ1 and FtsZ2) and another bacterial cell division homologue (SepF), which are part of the midcell division ring. Here, we identify an additional protein (HVO_0739, renamed CdpA) that is involved in cell division in Haloferax volcanii, with homologues in other Haloarchaea. CdpA localizes at the mid-cell division ring, and this requires the presence of the ring-assembly protein FtsZ1. The division constriction protein FtsZ2 also influenced the proper midcell assembly and structure of CdpA. In the absence of CdpA, cells frequently failed to divide properly, and FtsZ1 formed poorly condensed pseudo-helical structures spanning across a broad region of the cell, whereas FtsZ2 showed mispositioned foci, nano-rings, and filaments. The rate of directional movement of FtsZ1 and FtsZ2 structures around the division ring appeared minimally affected by loss of CdpA, which resulted in continual repositioning of the aberrant FtsZ structures in the cells. In contrast to the FtsZ proteins, CdpA formed relatively immobile foci around the ring. Protein domain function studies, pull-down assays, and multimer structure predictions suggest that CdpA is part of a membrane complex that tethers FtsZ2 and other division proteins to the midcell membrane. Our discovery of an archaeal FtsZ organisation and midcell anchor protein offers new insights into cell division mechanisms that are similar across the tree of life.

microbiology↗

bioRxiv2024

A safe and effective method for thin cornea cross-linking

The mechanical properties of the collagen matrix determine the corneal regularity. Thus, corneal thinning, cone-like protrusion, and loss of corneal astigmatism characterize corneal ecstatic diseases, including keratoconus and post-LASIK ectasia. Currently, riboflavin (RF)/ultraviolet A (UVA) based corneal collagen cross-linking (CXL) is commonly used in clinics to stiffen cornea and halt disease progression in patients. However, due to tissue damage, especially irreversible endothelium loss, standard RF/UVA protocol is only allowed in eyes with corneal thickness over 400 m after epithelium debridement. Thus, lots of patients with thin cornea have limited therapeutic options. Here, we introduced a new strategy to cross-link cornea collagens using synthesized photo-initiators lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) and visible blue light (BL). The LAP/BL protocol could effectively increase corneal stiffness, similar to the RF/UVA protocol in both porcine and rabbit cornea. When the LAP/BL protocol was used, both epithelial wound healing, stromal cell repopulation, and corneal edema recovery rates were accelerated compared with the RF/UVA protocol. More importantly, as BL is used instead of UVA, corneal endothelium was mostly preserved in both rabbit and mouse models even when cornea thickness was as thin as 100 m. In summary, we propose that the LAP/BL protocol is a safe and effective choice for thin cornea CXL.

bioengineering↗