Search Results (48)

Chronic hepatitis B virus (HBV) infection remains one of the main causes of hepatocellular carcinoma (HCC), even though vaccination and long-term viral suppression have reduced new infections and circulating viral replication. This residual cancer risk suggests that serum HBV DNA alone does not capture the full biology of HBV-related carcinogenesis. Hepatitis B virus X protein (HBx) is a relevant entry point because it maintains the transcriptional competence of covalently closed circular DNA (cccDNA), engages host chromatin regulators, and may persist in tumors as cccDNA-derived, integration-derived, full-length, truncated, or fusion forms. This review focuses on a specific question: does the available literature support HBx-associated reactivation of the IGF2 locus in chronic HBV infection and HBV-related hepatocarcinogenesis, and, if so, at which regulatory layer is the claim defensible? The most direct evidence remains promoter-proximal. Classic mechanistic work shows acute HBx-dependent activation of IGF2 promoter P4 through Sp1- and PKC/ERK-dependent signaling. Human tissue and cell-based studies also support a broader fetal-promoter compartment, including P3/P4 transcript enrichment, local promoter hypomethylation, MBD2-HBx-CBP/p300 recruitment, and increased histone H3/H4 acetylation. These observations do not, however, establish HBV exclusivity, uniform loss of imprinting, or direct HBx-mediated rewiring of the human IGF2/H19 topological domain. Recent integration-aware and long-read studies further argue against treating tumor-stage HBx as a single biological variable. In the present evidence framework, HBx-associated IGF2 locus reactivation is therefore more appropriately viewed as a stage-aware, promoter-resolved, biomarker-oriented hypothesis than as a universal mechanism or a treatment algorithm for HBV-related HCC. Full article

Ischemic heart disease (IHD) is a chronic and progressive condition characterized by reduced blood flow, mainly due to atherosclerosis. It is currently the leading cause of mortality among cardiovascular diseases. In recent years, per- and polyfluoroalkyl substances (PFAS), a group of ubiquitous and highly persistent environmental contaminants, have emerged as potential risk factors for IHD. PFAS are well-established endocrine disruptors and have been associated with hypercholesterolemia, hypertriglyceridemia, and insulin resistance. Despite the limited number of epidemiological studies and inconsistent findings from occupational settings, accumulating evidence suggests that elevated exposure to certain PFAS compounds may increase the risk of IHD and vascular dysfunction, including processes related to atherosclerosis development, sometimes with dose–response relationships and sex-specific patterns. Mechanistic evidence supports this link, indicating that PFAS exposure induces molecular and cellular alterations relevant to cardiovascular pathophysiology, including increased oxidative stress and vascular inflammation, and disruption of lipid metabolism. In addition, PFAS may affect epigenetic regulation, telomere length, and mitochondrial DNA copy number, which are emerging biomarkers associated with atherosclerosis and IHD and may indicate early cardiovascular vulnerability. Future research integrating innovative approaches and advanced analytical techniques may help address current knowledge gaps and clarify the mechanistic pathways linking PFAS exposure to clinical cardiovascular outcomes. Full article

Wastewater from food processing industries contains synthetic dyes and preservatives that may pose phytotoxic and genotoxic risks. The present work represents an exploratory study based on a wastewater source and sampling period. Wastewater was characterized by physicochemical analysis and high-performance liquid chromatography (HPLC). Onion seeds and bulbs were exposed to 0% (control), 20%, 40%, 60%, 80%, and 100% wastewater dilution. DNA was extracted from root cells using the cetyltrimethylammonium bromide (CTAB) method. The DNA damage was analyzed by the comet assay. HPLC analysis confirmed the presence of sorbic acid, citric acid, benzoic acid, butylated hydroxyanisole (BHA), and butylated Hydroxytoluene (BHT) by showing corresponding peaks. The mean root length in wastewater was significantly reduced by 55%, 50%, and 65% on days 3, 5, and 7, respectively, relative to the control. On day 3, the highest genotoxicity at 100% wastewater was indicated by 96.69% tail DNA, a tail moment of 108.3 a.u., an Olive tail moment of 58.01 a.u., and a comet length of 136 µm. Enhanced DNA damage persisted on days 5 and 7, with comet lengths reaching 127–149 µm and 111–182 µm, respectively. Although the observed effects may reflect general cytotoxicity arising from a complex wastewater mixture and showed that untreated food processing wastewater presents a significant genotoxic risk and requires effective treatment prior to reuse. Full article

The Balkan mountain ranges are major hotspots of genetic diversity and endemism, yet many species remain poorly studied. One such species is Alyssum bosniacum, a narrow endemic of the Central Dinaric Alps. To fill this gap, we examined 143 individuals from 15 populations across the species’ range using flow-cytometric ploidy determination, amplified fragment length polymorphisms (AFLPs), nuclear microsatellites, and chloroplast DNA sequences. Microsatellite data revealed two genetic clusters, showing moderate differentiation and relatively high diversity. AFLP profiles indicated shallow but geographically structured variation, while chloroplast haplotypes showed limited divergence and regional clustering. Our data suggest possible persistence in multiple microrefugia within the Central Dinaric Alps, although further evidence is needed to confirm this scenario. Despite range fragmentation, genetic variation within the population remains high, indicating evolutionary resilience and supporting the species’ long-term future population stability under current conditions. Full article

In this study, the changes in the DNA native conformation induced by pH changes in the alkaline and acidic regions were examined. It was shown by the methods of low gradient viscometry and flow birefringence that protonation and deprotonation of nitrogen bases inside the double helix cause a change in the persistent length of DNA. The pK values shift with the change in the ionic strength of the solution (NaCl concentration). The additional charges appearing on the DNA bases are not shielded by counterions from the solution. The increase and decrease in the volume of the DNA coil in solution resulting from protonation and deprotonation of base pairs, respectively, are mainly determined by changes in the persistent length of the macromolecule. The stability of the double-helical conformation of DNA ensures the steadiness of the equilibrium rigidity of this macromolecule. The emergence of charges on the bases, resulting from DNA protonation or deprotonation, weakens and even disrupts the hydrogen bonds between complementary bases. However, at the first stage, this occurs without altering the stacking interactions of base pairs, as reflected in the absorption spectra of DNA and in the stability of the DNA persistent length at different pH levels. Full article

Upon an organism’s death, enzymatic DNA repair ceases, exposing the genome to destructive factors such as free cellular nucleases and proliferating microorganisms, which can cause DNA loss. DNA preservation is highly dependent on environmental conditions, and less favorable environments accelerate degradation. Despite this, advanced extraction and analytical methods now enable the study of poorly preserved and degraded DNA. DNA typing is a foundation of forensic genomics, enabling the identification of individuals and the individualization of biological evidence through the generation of unique genetic profiles. Although DNA is relatively stable, environmental exposure initiates its degradation into progressively shorter fragments, complicating analysis. The extent of DNA preservation in biological evidence depends on numerous factors, and this review focuses on the environmental factors—including temperature, humidity, ultraviolet radiation, pH, chemical agents, and microbial activity—as the most influential variables. In samples with degraded DNA, the maximum amplicon length achievable through polymerase chain reaction (PCR) is inherently limited. This review discusses genetic markers and analytical strategies improvements that enable the examination of highly degraded samples, particularly when conventional short tandem repeat (STR) typing fails. In these situations, successful identification requires targeting short DNA fragments, which are more likely to persist. Single-nucleotide polymorphisms (SNPs) are a valuable alternative, as their high allelic variability and short amplicon requirements make them more amenable to amplification from fragmented templates than STRs. Advances in next-generation sequencing (NGS) technologies have further enhanced this capacity by enabling high-resolution SNP profiling, thereby improving outcomes in challenging forensic cases. Full article

Persistent diarrhea remains a significant cause of morbidity in young children, yet the role of gut microbiota has not been fully clarified. This prospective study evaluated the diversity and predicted functions of the gut microbiota in 30 children aged 6–24 months with persistent diarrhea of unknown etiology (patient group, PG) and 30 healthy controls (healthy group, HG). Nearly full-length 16S rRNA genes from fecal bacterial metagenomic DNA were sequenced and taxonomically annotated. Subsequently, all downstream analyses, including diversity assessment, differential abundance and functional prediction analyses, and data visualization, were performed using R software (version 4.5.0, 2025). The PG showed lower Shannon and higher Simpson indices than the HG (p < 0.05), reflecting reduced microbial diversity. At the phylum level, Firmicutes predominated in the PG, whereas Actinobacteriota, Bacteroidota, and Verrucomicrobiota were more abundant in the HG (|log₂FC| > 1 and FDR < 0.05). At the genus and species levels, the PG exhibited a marked depletion of essential commensals such as Bifidobacterium longum, Faecalibacterium, Lactobacillus, and Eubacterium, alongside an enrichment of opportunistic taxa including Klebsiella, Enterococcus lactis, and Streptococcus spp. (FDR < 0.05). Functional predictions using PICRUSt2 indicated an enrichment of carbohydrate metabolism and reductions in amino acid metabolism, B-vitamin pathways, and the biosynthesis of endogenous antibiotics (FDR < 0.05). These findings suggest that the PG harbors a dysbiotic gut microbiota characterized by reduced diversity, depletion of key commensal taxa, expansion of opportunistic bacteria, and potentially adverse shifts in metabolic functions. Full article

Protein–DNA and protein–RNA interactions are central to gene regulation and genetic disease, yet experimental identification remains costly and complex. Machine learning (ML) offers an efficient alternative, though challenges persist in representing protein sequences due to residue variability, dimensionality issues, and the risk of losing biological context. Traditional approaches such as k-mer counting or neural network encodings provide standardized sequence representations but often demand high computational resources and may obscure functional information. To address these limitations, a novel encoding method based on interpolation of physicochemical properties (PCPs) is introduced. Discrete PCPs values are transformed into continuous functions using logarithmic enhancement, highlighting residues that contribute most to nucleic acid interactions while preserving biological relevance across variable sequence lengths. Statistical features extracted from the resulting spectra via Tsfresh are then used for binary classification of DNA- and RNA-binding proteins. Six classifiers were evaluated, and the proposed method achieved up to 99% accuracy, precision, recall, and F1 score when amino acid highlighting was applied, compared with 66% without highlighting. Benchmarking against k-mer and neural network approaches confirmed superior efficiency and reliability, underscoring the potential of this method for protein interaction prediction. Our framework may be extended to multiclass problems and applied to the study of protein variants, offering a scalable tool for broader protein interaction prediction. Full article

In Lolium perenne, a novel growth habit mutant, named VIROIZ, was recovered following colchicine treatment, and it was confirmed to maintain the diploid chromosome number (2n = 2x = 14). The mutation affected the stem morphology by inducing prolific axillary shoot formation at nodal zones, resulting in a spreading growth habit that can extend to ~70 cm in width. Inheritance analysis based on single-plant evaluations in crosses with wild-type plants (F₁, n = 285; F₂, n = 380) and in selfed progeny (S₁, n = 255) consistently showed ~40% expression of the spreading phenotype, deviating from classical Mendelian ratios and indicating complex genetic control. Phenotypic selection further distinguished divergent classes: positively selected lines (C1⁺) averaged 3.90 axillary tillers per stem, whereas negatively selected lines (C1⁻) averaged only 0.22. Partial sequencing of 11 candidate genes implicated in shoot architecture, covering 40–90% of full-length DNA, did not provide a conclusive explanation for the altered stem growth. Notably, a single point mutation was observed in CRT3 (an endoplasmic reticulum chaperone that interacts with brassinosteroid signaling) highlighting it as a primary target for future studies. Cytological analysis of meiosis in F₁ hybrids between VIROIZ and wild-type plants revealed irregular chromosome pairing with persistent univalents (2–4 per cell), supporting the presence of structural chromosomal rearrangements that may disrupt gene organization and function in VIROIZ. The non-Mendelian segregation of the spreading phenotype, together with the observed meiotic irregularities, suggests that the mutation affects regulatory genes responsive to hormonal signals controlling axillary meristem initiation. The mutant represents a valuable resource for turf-type L. perenne breeding and for studying hormonal regulation of shoot morphogenesis in Poaceae. Full article

Epigenetic modifications play a crucial role in gene regulation and have been implicated in various physiological processes and disease conditions. DNA methylation (DNAm) has been implicated in the etiology and progression of many stress-related psychiatric behaviors, such as depression. The ability to manipulate DNAm may provide a means to reverse and treat such disorders. Although CRISPR-based technologies have enabled locus-specific DNAm editing, their clinical applicability may be limited due to immunogenicity concerns and off-target effects. In this study, we introduce a novel approach for targeted DNAm manipulation using single-stranded methylated DNA probes. The probes were designed against the GRE of FKBP5 and the promoter region of MAOA. In both human embryonic kidney HEK293 and mouse pituitary AtT-20 cells, transfection with their respective methylated probes significantly increased DNAm at targeted CpG sites in a persistent and dose-dependent manner. Importantly, the induced methylation effectively attenuated glucocorticoid-induced upregulation of FKBP5 gene expression. Alteration of methylation was specific to single-stranded probes, as double-stranded methylated probes and unmethylated probes showed no significant effects. Some limitations include the need to further characterize factors that influence probe efficiency, such as probe length and CpG density; develop an efficient in vivo probe delivery system; and perform a more extensive consideration of possible off-target effects. Despite these limitations, our findings suggest that methylated DNA probes have the potential to function as a simple tool for targeted epigenetic manipulation and serve as a safer alternative to CRISPR-based epigenome editing tools for the treatment of stress-related disorders such as depression. Full article

R-loops are nucleic acid structures composed of an RNA-DNA hybrid (RDH) duplex and a displaced single-stranded DNA (ssDNA), which are fundamentally involved in key biological functions, including transcription and the preservation of genome stability. In an R-loop, the RDH duplex is bent by the folded secondary structures of the displaced ssDNA. Previous experiments and simulations indicated the high bendability of DNA below the persistence length. However, the bendability of a short RDH duplex remains unclear. Here, we report that an RDH duplex exhibits higher bendability than a DNA duplex on the short length scale using single-molecule cyclization experiments. Our molecular dynamics simulations show that an RDH duplex has larger intrinsic curvature and structural fluctuations and more easily forms kinks than DNA, which promote the bending flexibility of RDH from unlooped structures. Interestingly, we found that an RDH duplex composed of a C-rich DNA strand and a G-rich RNA strand shows significantly higher bendability than that composed of a G-rich DNA strand and a C-rich RNA strand in the same CpG island promoter regions, which may contribute to the formation of an R-loop. These findings shape our understanding towards biological processes involving R-loops through the high and sequence-dependent bendability of an RDH duplex. Full article

A proviral reservoir persists within the central nervous system (CNS) of people with HIV, but its characteristics remain poorly understood. Research has primarily focused on cerebrospinal fluid (CSF), as acquiring brain tissue is challenging. We examined size, cellular tropism, and infection-dynamics of the viral reservoir in post-mortem brain tissue from five individuals on and off antiretroviral therapy (ART) across three brain regions. Microglia-enriched fractions (CD11b⁺) were isolated and levels of intact proviral DNA were quantified (IPDA). Full-length envelope reporter viruses were generated and characterized in CD4⁺ T cells and monocyte-derived microglia. HIV DNA was observed in microglia-enriched fractions of all individuals, but intact proviruses were identified only in one ART-treated individual, representing 15% of the total proviruses. Phenotypic analyses of clones from this individual showed that 80% replicated efficiently in microglia and CD4⁺ T cells, while the remaining viruses replicated only in CD4⁺ T cells. No region-specific effects were observed. These results indicate a distinct HIV brain reservoir in microglia for all individuals, although intact proviruses were detected in only one. Given the unique immune environment of the CNS, the characteristics of microglia, and the challenges associated with targeting these cells, the CNS reservoir should be considered in cure strategies. Full article

Background/Objectives: Inflammatory bowel disease (IBD) is a persistent inflammatory condition affecting the gastrointestinal tract, distinguished by the impairment of the intestinal epithelial barrier, dysregulation of the gut microbiota, and abnormal immune responses. Cajanus cajan (L.) Millsp., traditionally used in Chinese herbal medicine for gastrointestinal issues such as bleeding and dysentery, has garnered attention for its potential therapeutic benefits. However, its effects on IBD remain largely unexplored. Methods: In this study, the major compounds from Cajanus cajan leaf extract (CCLE) were initially characterized by LCMS-IT-TOF. The IBD model was developed in C57BL/6 mice by administering continuous 4% (w/v) dextran sodium sulfate (DSS) aqueous solution over a period of seven days. The body weight, colon length, disease activity index (DAI), and histopathological examination using hematoxylin and eosin (H&E) staining were performed in the IBD model. The levels of the main inflammatory factors, specifically TNF-α, IL-1β, IL-6, and myeloperoxidase (MPO), were quantified by employing enzyme-linked immunosorbent assay (ELISA) kits. Additionally, the levels of tight junction proteins (ZO-1, Occludin) and oxidative stress enzymes (iNOS, SOD1, CAT) were investigated by qPCR. Subsequently, flow cytometry was employed to analyze the populations of various immune cells within the spleen, thereby assessing the impact of the CCLE on the systemic immune homeostasis of IBD mice. Finally, 16S rDNA sequencing was conducted to examine the composition and relative abundance of gut microbiota across different experimental groups. In addition, molecular docking analysis was performed to assess the interaction between the principal components of CCLE and the aryl hydrocarbon receptor (AHR). Results: We identified seven bioactive compounds in CCLE: catechin, cajachalcone, 2-hydroxy-4-methoxy-6-(2-phenylcinyl)-benzoic acid, longistylin A, longistylin C, pinostrobin, amorfrutin A, and cajaninstilbene acid. Our results demonstrated that oral administration of CCLE significantly alleviates gastrointestinal symptoms in DSS-induced IBD mice by modulating the balance of gut-derived pro- and anti-inflammatory cytokines. This modulation is associated with a functional correction in M1/M2 macrophage polarization and the Th17/Treg cell balance in splenic immune cells, as well as shifts in the populations of harmful bacteria (Erysipelatoclostridium and Staphylococcus) and beneficial bacteria (Odoribacter, unidentified Oscillospiraceae, Lachnoclostridium, and Oscillibacter) in the gut. Furthermore, cajaninstilbene acid, longistylin A, and longistylin C were identified as potential AhR agonists. Conclusions: The present results suggested that CCLE, comprising stilbenes like cajaninstilbene acid, longistylin A, and longistylin C, protects the epithelial barrier’s structure and function against DSS-induced acute IBD by restoring gut microbiota balance and systemic immune response as AhR agonists. Overall, CCLE represents a promising natural product-based therapeutic strategy for treating IBD by restoring gut microbiota balance and modulating systemic immune responses. Full article

Persistent high-risk human papillomaviruses (HR HPVs) infection leads to the development of squamous intraepithelial lesions in cervical cells that may lead to cancer. The telomere length, telomerase activity, and species composition of the vaginal microbiome may influence the dynamic of changes and the process of carcinogenesis. In the present study, we analyze relative telomere length (RTL), relative hTERT expression (gene for the telomerase component—reverse transcriptase) in cervical smear cells and vaginal microbiomes. Total RNA and DNA were isolated from tissue samples of 109 patients from the following groups: control, carrier, low-grade or high-grade squamous intraepithelial lesion (L SIL and H SIL, respectively), and cancer. The quantitative PCR method was used to measure telomere length and telomerase expression. Vaginal microbiome bacteria were divided into community state types using morphotype criteria. Significant differences between histopathology groups were confirmed for both relative telomere length and relative hTERT expression (p < 0.001 and p = 0.001, respectively). A significant difference in RTL was identified between carriers and H SIL (p adj < 0.001) groups, as well as between carriers and L SIL groups (p adj = 0.048). In both cases, RTL was lower among carriers. The highest relative hTERT expression level was recorded in the H SIL group, and the highest relative hTERT expression level was recorded between carriers and the H SIL group (p adj < 0.001). A correlation between genotype and biocenosis was identified for genotype 16+A (p < 0.001). The results suggest that identification of HPV infection, telomere length assessment, and hTERT expression measurement together may be more predictive than each of these analyses performed separately. Full article

Telomere shortening, chromosomal damage, and mitochondrial dysfunction are major initiators of cell aging and biomarkers of many diseases. However, the underlying correlations between nuclear and mitochondrial DNA alterations remain unclear. We investigated the relationship between telomere length (TL) and micronucleus (MN) and their association with mitochondrial DNA copy number (mtDNAcn) in peripheral blood mononuclear cells (PBMCs) in response to 100 μM and 200 μM of hydrogen peroxide (H₂O₂) at 44, 72, and 96 h. Significant TL shortening was observed after both doses of H₂O₂ and at all times (all p < 0.05). A concomitant increase in MN was found at 72 h (p < 0.01) and persisted at 96 h (p < 0.01). An increase in mtDNAcn (p = 0.04) at 200 µM of H₂O₂ was also found. In PBMCs treated with 200 µM H₂O₂, a significant inverse correlation was found between TL and MN (r = −0.76, p = 0.03), and mtDNA content was directly correlated with TL (r = 0.6, p = 0.04) and inversely related to MN (r = −0.78, p = 0.02). Telomere shortening is the main triggering mechanism of chromosomal damage in stimulated T lymphocytes under oxidative stress. The significant correlations between nuclear DNA damage and mtDNAcn support the notion of a telomere–mitochondria axis that might influence age-associated pathologies and be a target for the development of relevant anti-aging drugs. Full article