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Biology subjects

Jeon, Y.

Publications and source records attributed to Jeon, Y..

At least 19 recordsLinked to original sources

Sensitizing tumor response to topoisomerase I antibody drug conjugate by selective CDK7 inhibition

This study investigates the transcriptional impact of Q901, a highly selective CDK7 inhibitor in clinical development. Q901 primarily disrupted MYC and E2F-dependent transcription program, downregulating cell cycle control and DNA damage repair pathways. CDK7 binding at the promoter-proximal regions was dramatically stabilized by Q901, leading to reduced occupancy of MYC, E2F, and RNA Polymerase II (RNAPII). These findings offered a novel therapeutic strategy to enhance cancer susceptibility to TOP1-DNA protein crosslinks (TOP1-DPCs) induced by TOP1 inhibitors. Resistance to TOP1 inhibitors arises through activation of DNA repair pathway when elongating RNAPII encounters TOP1-DPCs. By suppressing RNAPII transition from initiation to elongation and DNA repair pathways, Q901 stabilizes TOP1-DPCs and sensitizes tumor to TOP1 inhibitors. Preclinical studies demonstrated enhanced tumor suppression when combining Q901 with TOP1 inhibitor-based antibody-drug conjugates (TOP1i-ADCs), highlighting its potential as a therapeutic option for cancers resistant to TOP1i-ADC therapy. TeaserOvercoming ADC cross-resistance through combination approach.

cancer biology↗

Telomere-to-Telomere Accurate and Gapless Korean Standard Reference Genome

We present KOREF1-G-TTAGGA, the first Telomere-to-Telomere Accurate and Gapless Genome Assembly, standing as the Korean standard reference genome. The paternal and maternal haplotypes spanned 2.91 and 3.03 Gb. Genome-wide, at least 99.15% of assembled sequences were reliably haplotype-resolved, and over 95% remained accurate even in the most error-prone loci, including centromeric satellite arrays and segmental duplications. Rare-k-mer copy-number concordance within satellite arrays held up 98.9% and 98.8% per haplotype. Bionano optical maps fully spanned all canonical rDNA arrays on the five acrocentric chromosomes. The assembly quality index (AQI) of 99.77 and 99.69 exceeded the reference-quality threshold of 90, and more than 99.99% of gene and cCRE sequence was free of structural error. Both haplotypes further showed high base-level accuracy, with consensus quality value (QV) of 81.19 and 79.03, corresponding to one error per 131 and 80 Mb. KOREF1-G-TTAGGA is among the highest-quality East Asian telomere-to-telomere assemblies. It moreover anchors a decade-spanning multi-ome reference dataset for defining individual molecular states. Together, these resources define the personal referenceome as a foundation for individual biology and precision medicine, with the assemblies, annotations, and all multi-omic data openly available at https://koreanreference.org.

genomics↗

10,239 whole genomes with multiomic and clinical health information as the Korean population multiomic reference dataset

We present Korea10K, the largest genomic dataset of the Korean population, comprising 10,239 high-coverage whole genomes (mean depth 30x) with matched multiomic profiles and phenotype data. Korea10K achieves complete and near-complete discovery of very rare and ultra-rare alleles, respectively, at 9,000 Korean genomes. This dataset provides the high-quality population-specific imputation panel, enabling accurate inference of low-frequency variants. Admixture analyses confirm the genetic homogeneity of the Korean population, despite its diverse Y-chromosomal, mitochondrial, and HLA repertoires. This pattern reflects a long and continuous lineage history characterized by persistent internal admixture and genomic homogenization over thousands of years on the Korean peninsula. We also identified 16.8 million genomic variants that directly modify CG sites by creating or abolishing CG dinucleotides, providing the population-scale evidence of coordinated genomic-epigenomic regulatory mechanism in Koreans.

genomics↗

AGO1 in neural progenitor cells orchestrates brain development and sociability via LIN28A-REELIN axis

AGO1, an essential RNA binding protein (RBP) in RNA interference, is associated with autism spectrum disorder (ASD). However, the precise functions of AGO1 in brain development and related disorders remain largely unexplored. Here, we report the critical roles of AGO1 in neural progenitor cells (NPCs) in promoting sociability and shaping the structure of the developing brain. Ago1 knockout (KO) in the mouse brain leads to hyposociability, a characteristic symptom of ASD. In human forebrain organoids, AGO1 KO disrupts the formation of ventricle-like structures and delays cortical layer development. We discovered that AGO1 KO results in a loss of polarity in NPCs, which subsequently reduces neuronal development. These AGO1 KO phenotypes originate from the failure to suppress LIN28A in NPCs. AGO1 is primarily localized in the nucleus within NPCs and binds to the LIN28A promoter region, thereby inhibiting LIN28A transcription. We found that increased LIN28A in AGO1 KO NPCs reduces REELIN expression, a key regulator of brain development, by binding directly to the REELIN mRNA. The aberrant polarity phenotype in AGO1 KO NPCs was successfully ameliorated by either LIN28A knockdown or recombinant REELIN treatment. Collectively, our findings elucidate the intricate molecular mechanisms orchestrated by nuclear AGO1 in NPCs and underscores its pivotal roles in brain development, providing significant insights into ASD.

neuroscience↗

Human ribomes reveal DNA-embedded ribonucleotides as a new type of epigenetic mark

Ribonucleoside monophosphates (rNMPs) are abundant in DNA, but their distribution and function in human nuclear genomes remain unknown. Here, we mapped nearly one million rNMPs per genome across diverse human cell types, defining a nuclear "ribome" with non-random distribution patterns. rNMPs are enriched in C/G-rich sequences, epigenetically marked regions, and telomeres. Conserved ribonucleotide-enriched zones (REZs) overlap with CpG islands and R-loops. rNMP concentration near transcription start sites (TSSs) correlates positively with gene expression. Wild-type cells display a broader gene-expression range than ribonuclease H2A (RNH2A) knockouts, in which loss of rNMP cleavage causes pronounced retention of embedded rG and strand-biased rC near TSSs, both increasing with gene expression. These findings establish DNA-embedded rNMPs as a novel epigenetic mark that modulates human gene expression.

molecular biology↗

Identification of reactive CpGs and RNA expression in early COVID-19 through cis-eQTM analysis reflecting disease severity and recovery

Multi-omics analyses of severe COVID-19 cases are crucial in deciphering the complex interplay between genetic and epigenetic factors. Here, we present an analysis of Expression Quantitative Trait Methylation (eQTM) to investigate the complex interplay of methylation and gene expression pattern during the acute phase of severe COVID-19. We identified 16 differentially expressed genes and 30 nearby differentially methylated CpG sites. Six key genes--SRXN1, FURIN, IL18RAP, FOXO3, GCNT4, and FKBP5--were either up-regulated or down-regulated near hypomethylated CpG sites. These genes are associated with viral infiltration, immune activation, lung damage, and oxidative stress-related multi-organ failure, which are the hallmarks of severe COVID-19. Interestingly, during the recovery phase, methylation and gene expression levels returned to baseline, underscoring the rapid and reversible nature of these molecular changes. These findings provide insight into the dynamics of epigenetic and transcriptomic shifts according to the infectious stage, supporting potential prognostic and therapeutic approaches for severe COVID-19.

bioinformatics↗

Collectin-11 regulates osteoclastogenesis and bone maintenance via a complement-dependent mechanism.

The human developmental disorder 3MC syndrome is characterized by skeletal deformities associated with a deficiency of the pattern recognition molecule collectin-11 (CL-11), yet the underlying molecular and cellular mechanisms remain unclear. Here, we demonstrate that CL-11 deletion alone does not cause bone abnormalities in mice; however, combined deficiencies involving CL-11 and complement components MASP-2 (lectin pathway), CFB, or C3 (alternative amplification pathway) lead to significant vertebral bone loss and spinal curvature by 12 weeks of age. Ex vivo osteoclast (OCL) differentiation from bone marrow-derived cells of these double-knockout (DKO) mice was markedly impaired, but differentiation capacity was substantially restored by supplementation with CL-11. Furthermore, CL-11 and membrane attack complex (C5b-9) deposition were co-localized to OCLs and their precursors in normal bone tissues from embryonic stages to adulthood. These findings identify CL-11 as a critical osteoclastogenesis and bone maintenance regulator in conjunction with complement system-mediated signalling pathways and highlight CL-11 as a potential therapeutic target in diseases involving dysregulated osteoclast function and bone remodelling. Significance statementOur research in mice provides new insights into how mutations in the immune surveillance molecule collectin-11 contribute to skeletal abnormalities in humans. Evidence from our study suggests that normal osteoclasts interact with collectin-11 and complement, and that the disruption of this cooperation results in impaired bone maintenance in adulthood. These findings not only advance our understanding of osteoclast function but also highlight the therapeutic potential of targeting collectin-11 in conditions associated with osteoclast dysfunction.

immunology↗

Light-activated tetanus neurotoxin for conditional proteolysis and inducible synaptic inhibition in vivo

The light chain of tetanus neurotoxin (TeNT) is a 52 kD metalloprotease that potently inhibits synaptic transmission by cleaving the endogenous vesicle fusion protein VAMP2. To mitigate the toxicity of TeNT and harness it as a conditional tool for neuroscience, we engineered Light-Activated TeNT (LATeNT) via insertion of the light-sensitive LOV domain into an allosteric site. LATeNT was optimized by directed evolution and shown to have undetectable activity in the dark mammalian brain. Following 30 seconds of weak blue light exposure, however, LATeNT potently inhibited synaptic transmission in multiple brain regions. The effect could be reversed over 24 hours. We used LATeNT to discover an interneuron population in hippocampus that controls anxiety-like behaviors in mouse, and to control the secretion of endogenous insulin from pancreatic beta cells. Synthetic circuits incorporating LATeNT converted drug, Ca2+, or receptor activation into transgene expression or reporter protein secretion. Due to its large dynamic range, rapid kinetics, and highly specific mechanism of action, LATeNT should be a robust tool for conditional proteolysis and spatiotemporal control of synaptic transmission in vivo.

biochemistry↗

spaDesign: A Statistical Framework to Improve the Design of Sequencing-based Spatial Transcriptomics Experiments

MotivationRigorous experimental design is essential for obtaining biologically meaningful findings and high-throughput spatial transcriptomics studies are not an exception. While some efforts have been made to improve the design of these studies, it is still significantly understudied yet how to optimize key experimental factors of these experiments. In the case of sequencing-based spatial transcriptomics studies, determining the minimum sequencing depth is an important experimental factor to decide. ResultsTo address this critical limitation, here we propose spaDesign, a statistical framework to improve the design of sequencing-based spatial transcriptomics experiments. spaDesign is a statistically rigorously designed framework that employs Poisson Gaussian process and Fisher-Gaussian kernel mixture. It can easily simulate a range of spatial transcriptomics data with various sequencing depths, effect sizes, and spatial patterns, which allows rigorous estimation of needed total sequencing depths to detect spatial domains based on spatial transcriptomics experiments. We demonstrated the utility and power of spaDesign using 10X Visium data of the human brain and the chicken heart. AvailabilityThe R package and associated tutorial are freely available at https://github.com/JuanXie19/spaDesign.

bioinformatics↗

Xist RNA binds select autosomal genes and depends on Repeat B to regulate their expression

Xist, a pivotal player in X chromosome inactivation (XCI), has long been perceived as a cis-acting long noncoding RNA that binds exclusively to the inactive X chromosome (Xi). However, Xists ability to diffuse under select circumstances has also been documented, leading us to suspect that Xist RNA may have targets and functions beyond the Xi. Here, using female mouse embryonic stem cells (ES) and mouse embryonic fibroblasts (MEF) as models, we demonstrate that Xist RNA indeed can localize beyond the Xi. However, its binding is limited to [~]100 genes in cells undergoing XCI (ES cells) and in post-XCI cells (MEFs). The target genes are diverse in function but are unified by their active chromatin status. Xist binds discretely to promoters of target genes in neighborhoods relatively depleted for Polycomb marks, contrasting with the broad, Polycomb-enriched domains reported for human XIST RNA. We find that Xist binding is associated with down-modulation of autosomal gene expression. However, unlike on the Xi, Xist binding does not lead to full silencing and also does not spread beyond the target gene. Over-expressing Xist in transgenic ES cells similarly leads to autosomal gene suppression, while deleting Xists Repeat B motif reduces autosomal binding and perturbs autosomal down-regulation. Furthermore, treating female ES cells with the Xist inhibitor, X1, leads to loss of autosomal suppression. Altogether, our findings reveal that Xist targets [~]100 genes beyond the Xi, identify Repeat B as a crucial domain for its in-trans function in mice, and indicate that autosomal targeting can be disrupted by a small molecule inhibitor.

genomics↗

Identification of 17 novel epigenetic biomarkers associated with anxiety disorders using differential methylation analysis followed by machine learning-based validation

BackgroundThe changes in DNA methylation patterns may reflect both physical and mental well-being, the latter being a relatively unexplored avenue in terms of clinical utility for psychiatric disorders. In this study, our objective was to identify the methylation-based biomarkers for anxiety disorders and subsequently validate their reliability. MethodsA comparative differential methylation analysis was performed on whole blood samples from 94 anxiety disorder patients and 296 control samples using targeted bisulfite sequencing. Subsequent validation of identified biomarkers employed an artificial intelligence- based risk prediction models: a linear calculation-based methylation risk score model and two tree-based machine learning models: Random Forest and XGBoost. Results17 novel epigenetic methylation biomarkers were identified to be associated with anxiety disorders. These biomarkers were predominantly localized near CpG islands, and they were associated with two distinct biological processes: 1) cell apoptosis and mitochondrial dysfunction and 2) the regulation of neurosignaling. We further developed a robust diagnostic risk prediction system to classify anxiety disorders from healthy controls using the 17 biomarkers. Machine learning validation confirmed the robustness of our biomarker set, with XGBoost as the best-performing algorithm, an area under the curve of 0.876. ConclusionOur findings support the potential of blood liquid biopsy in enhancing the clinical utility of anxiety disorder diagnostics. This unique set of epigenetic biomarkers holds the potential for early diagnosis, prediction of treatment efficacy, continuous monitoring, health screening, and the delivery of personalized therapeutic interventions for individuals affected by anxiety disorders.

bioinformatics↗

Enriched zones of embedded ribonucleotides are associated with DNA replication and coding sequences in the human mitochondrial genome

Abundant ribonucleoside triphosphate (rNTP) incorporation in DNA by DNA polymerases in the form of ribonucleoside monophosphates (rNMPs) is a widespread phenomenon in nature, resulting in DNA structural change and genome instability. The rNMP distribution, characteristics, hotspots, and association with DNA metabolic processes in human mitochondrial DNA (hmtDNA) remain mostly unknown. Here, we utilize the ribose-seq technique to capture embedded rNMPs in mtDNA of six different human cell types with wild-type or mutant ribonuclease (RNase) H2 genotype. The rNMPs are preferentially embedded in the DNA of the light strand in most cell types studied, but not in the liver-tissue cells, in which the rNMPs are dominant on the heavy strand of hmtDNA. We uncover common rNMP hotspots and conserved rNMP-enriched zones across the entire hmtDNA, including in the replication-control region, which may result in the suppression of mtDNA replication. We also show that longer coding sequences have a significantly higher rNMP-embedment frequency per nucleotide. While the composition of the embedded rNMPs varies among the different cell types, by studying the genomic context of embedded rNMPs, we detected common rNMP-embedment patterns in hmtDNA. The genomic contexts of rNMPs found in hmtDNA are mainly distinct from those found in yeast mtDNA, highlighting a unique signature of rNTP incorporation by hmtDNA polymerase {gamma}.

genomics↗

Korea4K: whole genome sequences of 4,157 Koreans with 107 phenotypes derived from extensive health check-ups

We present 4,157 whole-genome sequences (Korea4K) coupled with 107 health check-up parameters as the largest whole genomic resource of Koreans. Korea4K provides 45,537,252 variants and encompasses most of the common and rare variants in Koreans. We identified 1,356 new geno-phenotype associations which were not found by the previous Korea1K dataset. Phenomics analyses revealed 24 genetic correlations, 1,131 pleiotropic variants, and 127 causal relationships from Mendelian randomization. Moreover, the Korea4K imputation reference panel showed a superior imputation performance to Korea1K. Collectively, Korea4K provides the most extensive genomic and phenomic data resources for discovering clinically relevant novel genome-phenome associations in Koreans.

genomics↗

RNA-mediated double-strand break repair in human cells

Double-strand breaks (DSBs) in DNA are challenging lesions to repair. Human cells employ at least three DSB repair mechanisms, with a preference for non-homologous end joining (NHEJ) over homologous recombination (HR) and microhomology-mediated end joining (MMEJ)1,2. In contrast to HR, NHEJ and MMEJ do not utilize a DNA template molecule to recover damaged and/or lost nucleotides2. NHEJ directly ligates broken DNA ends, while MMEJ exploits the alignment of short microhomologies on the DSB sides and is associated with deletions of the sequence between the microhomologies3,4. It is unknown whether and to what extent a transcript RNA has a direct role in DSB-repair mechanisms in mammalian cells. Here, we show that both coding and non-coding transcript RNA facilitates DSB repair in a sequence-specific manner in human cells. Depending on its sequence complementarity with the broken DNA ends, the transcript RNA could promote the repair of a DSB or gap in its DNA gene via NHEJ or MMEJ, or mediate RNA-templated repair. The transcript RNA influences DSB repair by NHEJ and MMEJ even when the transcription level is low. The results demonstrate an unexpected role of transcript RNA in directing the way DSBs are repaired in human cells and maintaining genome stability.

molecular biology↗

AIMP1-derived peptide secreted from hair follicle stem cells activates dermal papilla cells to promote hair growth

Hair follicle stem cells (HFSCs) and dermal papilla cells (DPCs) are crucial in the biogenesis and maintenance of hair follicles (HFs). In this study, a fragment derived from aminoacyl-tRNA synthetase-interacting multifunctional protein1 (AIMP1) was secreted from HFSCs to activate DPCs to maintain hair follicle homeostasis. A histological analysis revealed that AIMP1 levels in hair follicles decreased with hair loss. Hair regrowth in AIMP1-induced mice was faster than that in non-induced mice. Deletion mapping revealed 41 amino acids (TN41, aa 6-46) as the active region of AIMP1. The N-terminal peptide fragment of AIMP1 generated by MMP1 was secreted from Wnt-treated HFSCs to activate DPCs via FGFR2. TN41 activated Akt and ERK, increased {beta}-catenin, and enhanced DPCs activation. TN41 also promoted hair shaft elongation in cultured human hair follicles and improved the hair-inducing activity of cultured DPC spheroids. In summation, the AIMP1 fragment secreted from HFSCs appears to stimulate active hair regrowth through activating DPCs.

cell biology↗

Promoting axon regeneration by enhancing the non-coding function of the injury-responsive coding gene Gpr151

Gene expression profiling in response to nerve injury has been mainly focused on protein functions of coding genes to understand mechanisms of axon regeneration and to identify targets of potential therapeutics for nerve repair. However, the protein functions of several highly injury-induced genes including Gpr151 for regulating the regenerative ability remain unclear. Here we present an alternative approach focused on non-coding functions of the coding genes, which led to the identification of the non-coding function of Gpr151 RNA interacting with RNA- binding proteins such as CSDE1. Gpr151 promotes axon regeneration by the function of its 5- untranslated region (5UTR) and expression of an engineered form of the 5UTR improves regenerative capacity in vitro and in vivo in both sciatic nerve and optic nerve injury models. Our data suggest that searching injury-induced coding genes potentially functioning by their non- coding regions is required for the RNA-based gene therapy for improving axon regeneration.

neuroscience↗

Disproportionate presence of adenosine in mitochondrial and chloroplast DNA of Chlamydomonas reinhardtii

Ribonucleoside monophosphates (rNMPs) represent the most common non-standard nucleotides found in the genomic DNA of cells. The distribution of rNMPs in DNA has been studied only in limited genomes, such as yeast nuclear and mitochondrial DNA, as well as human mitochondrial DNA. In this study, we used the ribose-seq protocol and the Ribose-Map bioinformatics toolkit to reveal the distribution of rNMPs incorporated into the whole genome of a photosynthetic unicellular green alga, Chlamydomonas reinhardtii. The study presents the discovery of a disproportionate incorporation of adenosine in the mitochondrial and chloroplast DNA, in contrast to the nuclear DNA, relative to the nucleotide content of these C. reinhardtii genomes. Our results demonstrate that the rNMP content in the DNA of the algal organelles reflects an elevated ATP level present in the algal cells. In addition, we reveal specific rNMP biases and patterns in the mitochondrial, chloroplast and nuclear DNA of C. reinhardtii.

molecular biology↗

Complete genome sequence and analysis of nine Egyptian females with clinical information from different geographic regions in Egypt

Egyptians are at a crossroad between Africa and Eurasia, providing useful genomic resources for analyzing both genetic and environmental factors for future personalized medicine. Two personal Egyptian whole genomes have been published previously and here nine female whole genome sequences with clinical information have been added to expand the genomic resource of Egyptian personal genomes. Here we report the analysis of whole genomes of nine Egyptian females from different regions using Illumina short-read sequencers. At 30x sequencing coverage, we identified 12 SNPs that were shared in most of the subjects associated with obesity which are concordant with their clinical diagnosis. Also, we found mtDNA mutation A4282G is common in all the samples and this is associated with chronic progressive external ophthalmoplegia (CPEO). Haplogroup and Admixture analyses revealed that most Egyptian samples are close to the other north Mediterranean, Middle Eastern, and European, respectively, possibly reflecting the into-Africa influx of human migration. In conclusion, we present whole-genome sequences of nine Egyptian females with personal clinical information that cover the diverse regions of Egypt. Although limited in sample size, the whole genomes data provides possible geno-phenotype candidate markers that are relevant to the regions diseases.

bioinformatics↗