Biology subjects

Kan, C.

Publications and source records attributed to Kan, C..

6 recordsLinked to original sources

bioRxiv2025

HLA-DQ2/8 genotype imprints strain-level gut microbiome and constrains pantothenate availability in healthy adults

HLA-DQ2/8 haplotypes are established genetic risk factors for autoimmune diseases and are known to influence gut microbiota assembly in early life. However, their impact on the adult microbiome and functional consequences for host physiology remain unclear. Here, we performed a genotype-stratified multi-omics analysis of 60 healthy adults, including 28 HLA-DQ2/8 carriers and 32 non-carriers. We found that host HLA-DQ2/8 genotype was significantly associated with gut microbiome composition, with an effect size exceeding that of sex and BMI. HLA-DQ2/8 carriers exhibited higher gut microbial alpha-diversity, lower virulence factor abundance, and a distinct species profile enriched in butyrate-producing taxa. We identified pervasive intra-species phylogenetic and functional divergence linked to the DQ2/8 genotype. This diversification reflects predicted HLA-restricted microbial peptide-binding specificities, suggesting a possible role for antigen presentation-mediated immune selection, a mechanism further supported by AlphaFold3 structural modeling. We found an enrichment of microbial pathways for pantothenate and coenzyme A (CoA) biosynthesis in carriers, primarily driven by functionally divergent Blautia obeum strains. This functional shift paralleled lower levels of serum pantothenate and HDL-cholesterol in the host. Our findings suggest a potential genotype-microbiome-host axis where antigen presentation-mediated immune selection may modulate microbial adaptation, with possible implications for the host availability of essential cofactor precursors and lipid metabolism.

microbiology↗

bioRxiv2024

KIF18A in HCC Metastasis: Dual Role in Anoikis Resistance and Chromosome Instability

The study explores the role of KIF18A, a gene linked to whole-genome doubling (WGD) and chromosomal instability (CIN), in the metastatic progression of hepatocellular carcinoma (HCC). We found that KIF18A is a critical link between CIN and anoikis resistance, key factors in HCC metastasis. Through the bulk-seq analysis, we identified the pressures of anoikis and CIN faced by tumor cells during HCC metastasis and identified hub genes central to this process. Our results reveal that E2F activation during HCC progression leads to the transcription of KIF18A, promoting the survival and metastasis of CIN tumors. Overexpression of KIF18A leads to longer tumor life, more micronuclei, and increased survival and metastasis through non-canonical NF-kB activation. Deletion of KIF18A stabilizes the nuclear membrane of the micronucleus, silences cGAS-STING and PI3K-AKT pathways, and inhibits classical NF-kB. The studys limitations include the need for further animal studies to validate the findings and explore the transient activation of the cGAS-STING pathway. Additionally, future research could focus on the potential therapeutic implications of targeting KIF18A in cancer treatment.

cancer biology↗

bioRxiv2024

Allo-Allo: Data-efficient prediction of allosteric sites

Allostery, a fundamental structural mechanism where ligand binding at a protein site affects protein function at another site, plays a crucial role in key drug-target proteins like GPCRs. Unfortunately, existing methods for predicting allosteric sites have limited performance- they are particularly constrained by scarce ground-truth experimental data. We introduce Allo-Allo, a data-efficient, sequence-based method that predicts allosteric sites by leveraging protein language models (PLMs). Honing in on ESM-2 attention heads that capture allosteric residue associations, Allo-Allo achieves a 67% higher AUPRC than state-of-the-art methods. Our innovative, data-efficient pipeline not only outperforms alternate, commonly-used PLM-based prediction architectures but also generalizes well. Notably, mutations in Allo-Allo-predicted sites show significant association with elevated disease risk scores from AlphaMissense, highlighting its translational potential. Beyond Allo-Allos biological and translational applicability, its architecture presents a powerful framework for other data-scarce problems in protein analysis.

bioinformatics↗

bioRxiv2024

T1234: A distortion-matched structural scan solution to misregistration of high resolution fMRI data

PurposeHigh-resolution fMRI at 7T is challenged by suboptimal alignment quality between functional data and structural scans. This study aims to develop a rapid acquisition method that provides distortion-matched, artifact-mitigated structural reference data. MethodsWe introduce an efficient sequence protocol termed T1234, which offers adjustable distortions. This approach involves a T1-weighted 2-inversion 3D-EPI sequence with four spatial encoding directions optimized for high-resolution fMRI. A forward Bloch model was used for T1 quantification and protocol optimization. Twenty participants were scanned at 7T using both structural and functional protocols to evaluate the utility of T1234. ResultsResults from two protocols are presented. A fast distortion-free protocol reliably produced whole-brain segmentations at 0.8mm isotropic resolution within 3:00-3:40 minutes. It demonstrates robustness across sessions, participants, and three different 7T SIEMENS scanners. For a protocol with geometric distortions that matched functional data, T1234 facilitates layer-specific fMRI signal analysis with enhanced laminar precision. ConclusionThis structural mapping approach enables precise registration with fMRI data. T1234 has been successfully implemented, validated, and tested, and is now available to users at our center and at over 50 centers worldwide.

neuroscience↗

bioRxiv2024

Enhancing reproducibility and decentralization in single cell research with biocytometry

Biomedicine today is experiencing a shift towards decentralized data collection, which promises enhanced reproducibility and collaboration across diverse laboratory environments. This inter-laboratory study evaluates the performance of biocytometry, a method utilizing engineered bioparticles for enumerating cells based on their surface antigen patterns. In a decentralized framework, spanning 78 assays conducted by 30 users across 12 distinct laboratories, biocytometry consistently demonstrated significant statistical power in discriminating numbers of target cells at varying concentrations as low as 1 cell per 100,000 background cells. User skill levels varied from expert to beginner capturing a range of proficiencies. Measurement was performed in a decentralized environment without any instrument cross-calibration or advanced user training outside of a basic instruction manual. The results affirm biocytometry to be a viable solution for immunophenotyping applications demanding sensitivity as well as scalability and reproducibility and paves the way for decentralized analysis of rare cells in heterogeneous samples.

cell biology↗

bioRxiv2022

CLE42 Delays Leaf Senescence by Antagonizing Ethylene Pathway in Arabidopsis

Leaf senescence is the final stage of leaf development and is influenced by numerous internal and environmental factors. CLE family peptides are plant-specific peptide hormones that regulate various developmental processes. However, the role of CLE in regulating leaf senescence remains unclear. Here, we found that CLE42 is a negative regulator of leaf senescence by using a CRISPR/Cas9-produced CLE mutant collection. The cle42 mutant displayed earlier senescence phenotypes, while overexpression of CLE42 delayed age-dependent and dark-induced leaf senescence. Moreover, application of the synthesized 12-aa peptide (CLE42p) also delayed leaf senescence under natural and dark conditions. CLE42 and CLE41/44 displayed functional redundancy in leaf senescence, and the cle41 cle42 cle44 triple mutant displayed more pronounced earlier senescence phenotypes than any single mutant. Analysis of differentially expressed genes obtained by RNA-Seq methodology revealed that ethylene pathway was suppressed by overexpressing CLE42. Moreover, CLE42 suppressed ethylene biosynthesis and thus promoted the protein accumulation of EBF, which in turn decreased the function of EIN3. Accordingly, mutation of EIN3/EIL1 or overexpression of EBF1 suppressed the earlier senescence phenotypes of the cle42 mutant. Together, our results reveal that the CLE peptide hormone regulates leaf senescence by communicating with ethylene pathway.

plant biology↗