Human Genome Research Articles

Cell-free DNA release following psychosocial and physical stress in women and men.

Cell-free DNA (cfDNA) is continuously shed by all cells in the body, but the regulation of this process and its physiological functions are still largely unknown. Previous research has demonstrated that both nuclear (cf-nDNA) and mitochondrial (cf-mtDNA) cfDNA levels increase in plasma in response to acute psychosocial and physical stress in males. This study further investigated these findings by testing 31 female participants (16 using oral hormonal contraception and 15 not using oral hormonal contraception), and the results were subsequently compared with those of 16 male participants. In addition, cf-nDNA and cf-mtDNA were comparatively quantified in both plasma and saliva at four time points, 2 min before and 2, 15, and 45 min after stress induction. A novel method was implemented to facilitate the straightforward collection of capillary blood by non-medical personnel for plasma analysis. While cf-mtDNA is readily detectable in body fluids due to its high copy number, the quantification of cf-nDNA is challenging due to its low abundance. To overcome this, a multiplex quantitative polymerase chain reaction (qPCR) protocol targeting L1PA2 elements, which are prevalent in the human genome, was utilized. The analysis indicated significantly elevated levels of cf-nDNA in both plasma and saliva in all participants, irrespective of gender, following psychosocial and physical stress. Conversely, neither plasma nor saliva exhibited a consistent or stress-induced release pattern for cf-mtDNA. CfDNA is a promising biomarker that is consistently released after stress in both men and women and can be detected in both plasma and saliva. However, further research is necessary to elucidate the mechanisms of cfDNA release from specific cells and to understand its biological function in the body.

Personalising dietary advice for disease prevention: concepts and experiences.

Personalised nutrition (PN) as a new endeavour emerged in the background of the human genome project with the ease to analyse genetic heterogeneity. First commercial offers with recommendations for diet and lifestyle changes, usually based on a few polymorphisms, entered markets soon after the presentation of the human genome blueprint. Although PN has seen many attempts, meanwhile, with the inclusion of other biomedical measures such as microbiome and/or continuous glucose monitoring, scientific assessments of such approaches in various settings revealed limited success. Although personalisation improved general compliance over generic advice, particular benefits in referring to biomedical measures and individual risks did, in most cases, not provide any significant advantage. Moreover, scholars criticised such approaches as of limited impact from a public health perspective by attracting mainly technology-open individuals of high social status and proper financial capabilities. Based on these experiences, new avenues for personalising dietary advice are developed, and those are going beyond pure biomedical data by assessing the entire food environment of the individual with its capabilities and constraints in the given life setting. Embedded into digital environments for data collection but also for bidirectional communication, new possibilities emerge. Artificial intelligence methods allow for the multitude of input data and highly complex decision trees to be derived to customize advice. And that can be delivered on the spot and in time in any language whenever decisions are made on what to buy or what to eat. But systems can also be employed to increase physical activity levels and for the adoption of a more healthy lifestyle in general.

HgutMgene-Miner: In silico genome mining tool for deciphering the drug-metabolizing potential of human gut microbiome.

The biotransformation of drugs by enzymes from the human microbiome can produce active or inactive products, impacting the bioactivity and function of these drugs inside the human host. However, understanding the biotransformation reactions of drug molecules catalyzed by bacterial enzymes in human microbiota is still limited. Hence, to characterize drug utilization capabilities across all the microbial phyla inside the human gut, we have used a knowledge-based approach to develop HgutMgene-Miner software which predicts xenobiotic metabolizing enzymes (XMEs) through genome mining. HgutMgene-Miner derives its predictive power from the MicrobiomeMetDB database, which systematically catalogs all known biotransformation reactions of xenobiotics and primary metabolites mediated by host-associated microbial enzymes. Over 10,000 isolate genomes from 830 different bacterial species found in the Unified Human Gastrointestinal Genome (UHGG) collection have been analyzed by HgutMgene-Miner. This led to the identification of 89,377 xenobiotic metabolizing enzymes (XMEs) across 13 phyla, with the greatest diversity in Bacteroidota, Firmicutes_A, Firmicutes, and Proteobacteria. Bacteroides, Clostridium, and Alitsipes were found to be the richest genera, while Actinomyces were found to encode the fewest XMEs, primarily metabolizing Diclofenac, a nonsteroidal anti-inflammatory drug. Overall, we discovered XMEs in 220 genera, exceeding the number experimentally reported in fewer than 10 genera. Notably, Eggerthella lenta's cgr2 involved in Digoxin inactivation was identified in very distant Holdemania genera, likewise Clostridium leptum's nitroreductase, involved in Nitrazepam metabolism, was found in Fusobacterium. These findings highlight the extensive and diverse distribution of XMEs across microbial taxa.

RDNA Copy Number Variation and Methylation During Normal and Premature Aging.

Ribosomal RNA is the main component of the ribosome, which is essential for protein synthesis. The diploid human genome contains several hundred copies of the rDNA transcription unit (TU). Droplet digital PCR and deep bisulfite sequencing were used to determine the absolute copy number (CN) and the methylation status of individual rDNA TU in blood samples of healthy individuals. The absolute CN ranged from 243 to 895 (median 469). There was no difference in absolute CN between males and females and no gain or loss of copies with age (15-71 years). The number of rDNA TU with a completely unmethylated (0%) or lowly methylated (1%-10%) promoter region significantly decreased, whereas the number of copies with higher (11%-100%) methylation increased with age. The number of presumably active TU with a hypomethylated (0%-10%) promoter varied from 94 to 277 (median 180), independent from absolute CN. In contrast, the number of inactive hypermethylated (11%-100%) copies strongly increased with absolute CN. Promoter hypermethylation compensates to some extent for the enormous CN variation among individuals. Patients with Werner syndrome, a premature aging syndrome displayed the same CN variation and age-related methylation changes as controls. The role of rDNA CN variation as a modulating factor in human health and disease is largely unexplored. In particular, very low and high CN may be associated with increased disease risk.

ParSite is a multicolor DNA labeling system that allows for simultaneous imaging of triple genomic loci in living cells.

The organization of the human genome in space and time is critical for transcriptional regulation and cell fate determination. However, robust methods for tracking genome organization or genomic interactions over time in living cells are lacking. Here, we developed a multicolor DNA labeling system, ParSite, to simultaneously track triple genomic loci in the U2OS cells. The tricolor ParSite system is derived from the T. thermophilus ParB/ParSc (TtParB/ParSc) system by rational design. We mutated the interface between TtParB and ParSc and generated a new pair of TtParBm and ParSm for genomic DNA labeling. The insertions of 16 base-pair palindromic ParSc and ParSm into genomic loci allow dual-color DNA imaging in living cells. A pair of genomic loci labeled by ParSite could be colocalized with p53-binding protein 1 (53BP1) in response to CRISPR/Cas9-mediated double-strand breaks (DSBs). The ParSite permits tracking promoter and terminator dynamics of the APP gene, which spans 290 kilobases in length. Intriguingly, the hybrid ParS (ParSh) of half-ParSc and half-ParSm enables for the visualization of a third locus independent of ParSc or ParSm. We simultaneously labeled 3 loci with a genomic distance of 36, 89, and 352 kilobases downstream the C3 repeat locus, respectively. In sum, the ParSite is a robust DNA labeling system for tracking multiple genomic loci in space and time in living cells.

Overcoming challenges associated with broad sharing of human genomic data.

Since the Human Genome Project, the consensus position in genomics has been that data should be shared widely to achieve the greatest societal benefit. This position relies on imprecise definitions of the concept of 'broad data sharing'. Accordingly, the implementation of data sharing varies among landmark genomic studies. In this Perspective, we identify definitions of broad that have been used interchangeably, despite their distinct implications. We further offer a framework with clarified concepts for genomic data sharing and probe six examples in genomics that produced public data. Finally, we articulate three challenges. First, we explore the need to reinterpret the limits of general research use data. Second, we consider the governance of public data deposition from extant samples. Third, we ask whether, in light of changing concepts of broad, participants should be encouraged to share their status as participants publicly or not. Each of these challenges is followed with recommendations.

Stratification system with dual human endogenous retroviruses for predicting immunotherapy efficacy in metastatic clear-cell renal cell carcinoma

BackgroundEndogenous retrovirus (ERV) elements are genomic footprints of ancestral retroviral infections within the human genome. While the dysregulation of ERV transcription has been linked to immune cell infiltration in various...

Human Endogenous Retrovirus K in Astrocytes Is Altered in Parkinson's Disease.

Parkinson's disease (PD) is the most common neurodegenerative movement disease. Human endogenous retroviruses (HERVs) are proviral remnants of ancient retroviral infection of germ cells that now constitute about 8% of the human genome. Under certain disease conditions, HERV genes are activated and partake in the disease process. However, virtually nothing is known about the pathological relationship, if any, between HERV and PD. The objectives of this study were to unravel the pathological relationship between human endogenous retrovirus K (HERV-K) and PD, determine the localization of HERV-K in the brain, determine whether HERV-K levels are altered in PD brain and blood, and examine whether HERV-K could serve as a biomarker for PD. In situ HERV-K and glial fibrillary acidic protein (GFAP) expression in the superior frontal and fusiform cortices of PD and control brain were analyzed using immunofluorescence and confocal microscopy. HERV-K load and copy number in PD and control blood were measured by digital droplet polymerase chain reaction and GFAP by single-molecule array. HERV-K load was analyzed in relation to the Hoehn and Yahr Scale and Movement Disorder Society Unified Parkinson's Disease Rating Scale Part III. HERV-K is predominantly expressed in astrocytes and colocalized with astrocytic GFAP, with decreased expression of both HERV-K and GFAP in PD brain compared with controls. Consistent with this, HERV-K levels were decreased in PD blood compared with controls and were correlated to blood GFAP levels. HERV-K levels were inversely correlated to PD severity and duration. These findings suggest that HERV-K is related to astrocyte function and to PD progression, and that HERV-K could be neuroprotective. © 2025 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Diversity and consequences of structural variation in the human genome.

The biomedical community is increasingly invested in capturing all genetic variants across human genomes, interpreting their functional consequences and translating these findings to the clinic. A crucial component of this endeavour is the discovery and characterization of structural variants (SVs), which are ubiquitous in the human population, heterogeneous in their mutational processes, key substrates for evolution and adaptation, and profound drivers of human disease. The recentemergence of new technologies and the remarkable scale ofsequence-based population studies have begun to crystalize our understanding of SVs as a mutational class and their widespread influence across phenotypes. In this Review, we summarize recent discoveries and new insights into SVs in the human genome in terms of their mutational patterns, population genetics, functional consequences, and impact on human traits and disease. We conclude by outlining three frontiers to be explored by the field over the next decade.

SUMMER: an integrated nanopore sequencing pipeline for variants detection and clinical annotation on the human genome

Long-read sequencing has emerged as a transformative technology in recent years, offering significant potential for the molecular diagnosis of unresolved genetic disorders. Despite its promise, the comprehensive detection and clinical annotation of genomic variants remain intricate and technically demanding. We present SUMMER, an integrated and structured workflow specifically designed to process raw Nanopore sequencing reads. SUMMER facilitates an in-depth analysis of multiple variant types, including SNV, SV, short tandem repeat and mobile element insertion. For clinical applications, SUMMER employs SvAnna to prioritize SV candidates based on phenotype relevance and utilizes Straglr to provide reference distributions of non-pathogenic unit counts for 55 known pathogenic short tandem repeats. By addressing critical challenges in variant detection and annotation, SUMMER seeks to advance the clinical utility of long-read sequencing in diagnostic genomics. SUMMER is available on the web at https://github.com/carolhuaxia/summer.

Sequencing and characterizing human mitochondrial genomes in the biobank-based genomic research paradigm.

Human mitochondrial DNA (mtDNA) harbors essential mutations linked to aging, neurodegenerative diseases, and complex muscle disorders. Due to its uniparental and haploid inheritance, mtDNA captures matrilineal evolutionary trajectories, playing a crucial role in population and medical genetics. However, critical questions about the genomic diversity patterns, inheritance models, and evolutionary and medical functions of mtDNA remain unresolved or underexplored, particularly in the transition from traditional genotyping to large-scale genomic analyses. This review summarizes recent advancements in data-driven genomic research and technological innovations that address these questions and clarify the biological impact of nuclear-mitochondrial segments (NUMTs) and mtDNA variants on human health, disease, and evolution. We propose a streamlined pipeline to comprehensively identify mtDNA and NUMT genomic diversity using advanced sequencing and computational technologies. Haplotype-resolved mtDNA sequencing and assembly can distinguish authentic mtDNA variants from NUMTs, reduce diagnostic inaccuracies, and provide clearer insights into heteroplasmy patterns and the authenticity of paternal inheritance. This review emphasizes the need for integrative multi-omics approaches and emerging long-read sequencing technologies to gain new insights into mutation mechanisms, the influence of heteroplasmy and paternal inheritance on mtDNA diversity and disease susceptibility, and the detailed functions of NUMTs.

Assessing Human Ribosomal DNA Variation and Its Association With Phenotypic Outcomes.

Although genome-scale analyses have provided insights into the connection between genetic variability and complex human phenotypes, much trait variation is still not fully understood. Genetic variation within repetitive elements, such as the multi-copy, multi-locus ribosomal DNA (rDNA), has emerged as a potential contributor to trait variation. Whereas rDNA was long believed to be largely uniform within a species, recent studies have revealed substantial variability in the locus, both within and across individuals. This variation, which takes the form of copy number, structural arrangement, and sequence differences, has been found to be associated with human phenotypes. This review summarizes what is currently known about human rDNA variation, its causes, and its association with phenotypic outcomes, highlighting the technical challenges the field faces and the solutions proposed to address them. Finally, we suggest experimental approaches that can help clarify the elusive mechanisms underlying the phenotypic consequences of rDNA variation.

Structural insights into human topoisomerase 3β DNA and RNA catalysis and nucleic acid gate dynamics

Type IA topoisomerases (TopoIAs) are present in all living organisms. They resolve DNA/RNA catenanes, knots and supercoils by breaking and rejoining single-stranded DNA/RNA segments and allowing the passage of another nucleic acid segment through the break. Topoisomerase III-β (TOP3B), the only RNA topoisomerase in metazoans, promotes R-loop disassembly and translation of mRNAs. Defects in TOP3B lead to severe neurological diseases. We present a series of cryo-EM structures of human TOP3B with its cofactor TDRD3 during cleavage and rejoining of DNA or RNA, thus elucidating the roles of divalent metal ions and key enzyme residues in each step of the catalytic cycle. We also obtained the structure of an open-gate configuration that addresses the long-standing question of the strand-passage mechanism. Our studies reveal how TOP3B catalyzes both DNA and RNA relaxation, while TOP3A acts only on DNA.

Incomplete human reference genomes can drive false sex biases and expose patient-identifying information in metagenomic data

As next-generation sequencing technologies produce deeper genome coverages at lower costs, there is a critical need for reliable computational host DNA removal in metagenomic data. We find that insufficient host filtration using prior human genome references can introduce false sex biases and inadvertently permit flow-through of host-specific DNA during bioinformatic analyses, which could be exploited for individual identification. To address these issues, we introduce and benchmark three host filtration methods of varying throughput, with concomitant applications across low biomass samples such as skin and high microbial biomass datasets including fecal samples. We find that these methods are important for obtaining accurate results in low biomass samples (e.g., tissue, skin). Overall, we demonstrate that rigorous host filtration is a key component of privacy-minded analyses of patient microbiomes and provide computationally efficient pipelines for accomplishing this task on large-scale datasets.

P53 mediated regulation of LINE1 retrotransposon derived R-loops.

Long Interspersed Nuclear Element 1 (LINE1/L1) retrotransposons, which comprise 17% of the human genome, typically remain inactive in healthy somatic cells but are reactivated in several cancers. We previously demonstrated that p53 silences L1 transposons in human somatic cells, potentially acting as a tumor-suppressive mechanism. However, the precise molecular mechanisms underlying p53-mediated repression of L1 and its life cycle intermediates remain unclear. In this study, we used DRIP-sequencing experiments to investigate RNA-DNA hybrids, which are key intermediates formed during L1 retrotransposition. Our findings reveal that L1 mRNA-genomic DNA (cis L1 R-loops) and L1 mRNA-complementary DNA (trans L1 R-loops) hybrids, are de-repressed in p53-/- cells. This increase is synergistic with L1 activation by HDAC inhibitors (HDACi). However, treatment with a reverse transcriptase inhibitor reduces this accumulation, indicating that retrotransposition activity plays a significant role in R-loop accumulation. Interestingly, in p53 wild-type cells, hyperactivated L1 transposons are re-silenced upon HDACi withdrawal. L1 resilecing in wt cells coincided with the recruitment of repressive marks, specifically H3K9me3 and H3K27me3, simultaneously preventing the addition of activating marks like H3K4me3, and H3K9ac at the L1 5'UTR. Mechanistically, we demonstrate that p53 cooperates with histone methyltransferases SETDB1 and G9A to deposit H3K9me3 marks at the L1 promoter, thereby silencing transposons. This study is the first to reveal novel roles of p53 in preventing the formation of L1-derived RNA-DNA hybrids (R-loops) and re-silencing of hyperactivated L1 elements by co-operating with histone methyltransferases, underscoring its critical role in maintaining genomic stability.

Reciprocal and non-reciprocal effects of clinically relevant SETBP1 protein dosage changes.

Many genes in the human genome encode proteins that are dosage sensitive, meaning they require protein levels within a narrow range to properly execute function. To investigate if clinically relevant variation in protein levels impacts the same downstream pathways in human disease, we generated cell models of two SETBP1 syndromes: Schinzel-Giedion Syndrome (SGS) and SETBP1 haploinsufficiency disease (SHD), where SGS is caused by too much protein, and SHD is caused by not enough SETBP1. Using patient and sex-matched healthy first-degree relatives from both SGS and SHD SETBP1 cases, we assessed how SETBP1 protein dosage affects downstream pathways in human forebrain progenitor cells. We find that extremes of SETBP1 protein dose reciprocally influence important signalling molecules such as AKT, suggesting that the SETBP1 protein operates within a narrow dosage range and that extreme doses are detrimental. We identified SETBP1 nuclear bodies as interacting with the nuclear lamina and suggest that SETBP1 may organize higher order chromatin structure via links to the nuclear envelope. SETBP1 protein doses may exert significant influence on global gene expression patterns via these SETBP1 nuclear bodies. This work provides evidence for the importance of SETBP1 protein dose in human brain development, with implications for two neurodevelopmental disorders.

Targeted deaminase-free T-to-G and C-to-K base editing in rice by fused human uracil DNA glycosylase variants.

Targeted deaminase-free T-to-G and C-to-K base editing in rice by fused human uracil DNA glycosylase variants.

Massively parallel characterization of transcriptional regulatory elements.

The human genome contains millions of candidate cis-regulatory elements (cCREs) with cell-type-specific activities that shape both health and many disease states1. However, we lack a functional understanding of the sequence features that control the activity and cell-type-specific features of these cCREs. Here we used lentivirus-based massively parallel reporter assays (lentiMPRAs) to test the regulatory activity of more than 680,000 sequences, representing an extensive set of annotated cCREs among three cell types (HepG2, K562 and WTC11), and found that 41.7% of these sequences were active. By testing sequences in both orientations, we find promoters to have strand-orientation biases and their 200-nucleotide cores to function as non-cell-type-specific 'on switches' that provide similar expression levels to their associated gene. By contrast, enhancers have weaker orientation biases, but increased tissue-specific characteristics. Utilizing our lentiMPRA data, we develop sequence-based models to predict cCRE function and variant effects with high accuracy, delineate regulatory motifs and model their combinatorial effects. Testing a lentiMPRA library encompassing 60,000 cCREs in all three cell types further identified factors that determine cell-type specificity. Collectively, our work provides an extensive catalogue of functional CREs in three widely used cell lines and showcases how large-scale functional measurements can be used to dissect regulatory grammar.

DNA Methylation: Its Role and Interaction with Epigenetic Modifications in Cancer

DNA methylation is an epigenetic mark involving the addition of a methyl group to DNA, particularly at cytosine residues. This methylation plays an important role in regulating gene expression through direct gene repression or through the control of other epigenetic modifications such as histone modification or chromatin remodeling. DNA methylation is catalyzed by de novo and maintenance DNMT methyltransferase type enzymes and requires the transfer of a methyl group to cytosine to transform it into 5-methyl-cytosine. Currently, several investigations have highlighted the involvement of aberrant DNA methylation with certain tumors. Indeed, the methylation of antioncogenes and/or the demethylation of oncogenes are the major alterations that are strongly linked to human cancers. DNMTs play a central role in the epigenetic regulation of the human genome, both in normal and pathological processes. Recent discoveries on the differentiated roles of DNMTs in DNA methylation, and their implication in various cancers, open the way to new therapeutic approaches targeting these enzymes to treat epigenetic diseases. It is essential to continue exploring the roles of DNMTs to better understand their implication in tumorigenesis mechanisms and to develop more effective treatment strategies.

Exercise intensity and training alter the innate immune cell type and chromosomal origins of circulating cell-free DNA in humans

Exercising regularly promotes health, but these benefits are complicated by acute inflammation induced by exercise. A potential source of inflammation is cell-free DNA (cfDNA), yet the cellular origins, molecular causes, and immune system interactions of exercise-induced cfDNA are unclear. To study these, 10 healthy individuals were randomized to a 12-wk exercise program of either high-intensity tactical training (HITT) or traditional moderate-intensity training (TRAD). Blood plasma was collected pre- and postexercise at weeks 0 and 12 and after 4 wk of detraining upon program completion. Whole-genome enzymatic methylation sequencing (EM-seq) with cell-type proportion deconvolution was applied to cfDNA obtained from the 50 plasma samples and paired to concentration measurements for 90 circulating cytokines. Acute exercise increased the release of cfDNA from neutrophils, dendritic cells (DCs), and macrophages proportional to exercise intensity. Exercise training reduced cfDNA released in HITT participants but not TRAD and from DCs and macrophages but not neutrophils. For most participants, training lowered mitochondrial cfDNA at rest, even after detraining. Using a sequencing analysis approach we developed, we concluded that rapid ETosis, a process of cell death where cells release DNA extracellular traps, was the likely source of cfDNA, demonstrated by enrichment of nuclear DNA. Further, several cytokines were induced by acute exercise, such as IL-6, IL-10, and IL-16, and training attenuated the induction of only IL-6 and IL-17F. Cytokine levels were not associated with cfDNA induction, suggesting that these cytokines are not the main cause of exercise-induced cfDNA. Overall, exercise intensity and training modulated cfDNA release and cytokine responses, contributing to the anti-inflammatory effects of regular exercise.