DNA and cell biology最新文献

The increasing use of silver nanoparticles (AgNPs) in aquaculture has raised concerns regarding their potential toxic effects on fish health, particularly on vital organs, such as the liver and kidneys. Licorice (Glycyrrhiza glabra) root, known for its medicinal and antioxidant properties, has gained attention as a natural agent capable of mitigating such toxicity. Furthermore, licorice extract can be used in the eco-friendly green synthesis of AgNPs, acting as both a reducing and stabilizing agent, as confirmed by characterization techniques including X-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy. This study aimed to evaluate the protective effects of dietary licorice root powder against AgNP-induced histopathological and physiological damage in common carp (Cyprinus carpio). A total of 150 fish were randomly assigned to seven dietary treatment groups for 56 days, including a control group, three groups receiving increasing doses of AgNPs (2.5, 5, and 7.5 mg/kg feed), and three groups receiving corresponding combinations of same amount of AgNPs with licorice root powder (2.5, 5, and 7.5 g/kg feed). Histopathological evaluation revealed that AgNPs alone induced severe liver and kidney damage, including hydropic degeneration, necrosis, and inflammatory infiltration. In contrast, fish receiving licorice-supplemented diets showed significantly reduced tissue lesions, indicating hepatoprotective and nephroprotective effects. In conclusion, licorice root powder effectively mitigated AgNP-induced toxicity and improved organ health in common carp. The combination of licorice and AgNPs offers a promising alternative to antibiotics in aquaculture, enhancing sustainability and fish welfare. Further studies are recommended to investigate the underlying molecular mechanisms and optimize application strategies in fish diets and to investigate another model of animal.

Bromodomain-containing protein 4 (BRD4) is a pivotal transcriptional regulator implicated in cancer, fibrosis, and inflammation, yet its phospho-regulatory network remains underexplored. This study leverages an extensive analysis of 1000 qualitative and 225 quantitative global phosphoproteome datasets to decode the BRD4 phosphorylation landscape. We identified S601 and S1117 as predominant phosphorylation sites, driving the majority of BRD4 phospho-signaling. Co-regulation analysis revealed 755 and 972 proteins positively cophosphorylated with S601 and S1117, respectively, including key interactors like TRIM28 (S473) and PRKAR2A (S78), which enhance transcriptional activity and cAMP signaling. Upstream kinases MAPK14 and GRK5 emerged as high-confidence regulators of S1117 and S601, respectively, with correlations in breast cancer highlighting disease relevance. In addition, 93 phosphosites in 71 transcription factors co-regulated with S1117 and 69 in 53 with S601 underscore the role of BRD4 in transcription control. These findings unveil a complex phospho-signaling network, offering novel therapeutic targets for BRD4-associated diseases and a foundation for future experimental validation.

Three recent studies report the first biochemical reconstitution of DNA double-strand break (DSB) formation by SPO11, the topoisomerase-derived transesterase that initiates meiotic recombination in sexually reproducing organisms. A central conclusion of these studies is that SPO11 is sufficient to catalyze DSBs in vitro, but cleavage is limited by the poor propensity of SPO11 to dimerize, thereby providing an effective mechanism to prevent uncontrolled breaks. The studies yield new insights into the mechanism of DNA DSB formation and raise new questions regarding the functions of SPO11 partners, the impact of the DNA substrate, the coordination between cleavage events, and the reversibility of the reaction.

The common broad-spectrum protectant fungicide known as Dithianon is utilized in agriculture to manage pests; however, it could pose risks to human health. Dithianon may be associated with health problems due to its affinity for DNA. The interaction between Dithianon and calf thymus DNA (CT-DNA) was examined using UV-Vis absorption, fluorescence spectroscopy, and viscosity measurements with Neutral Red (NR) dye as a spectral probe in a physiological buffer. Dithianon, intercalated in DNA (K [DNA-Dithianon] = 2.3 × 10⁵ M^-1), causes the displacement of the NR dye from the NR-DNA complex. The binding constants (K_f), the number of binding sites (n ≈ 1), and thermodynamic parameters of the interaction of DNA-Dithianon were determined using the fluorescence quenching method at various temperatures. Dithianon's ability to intercalate in DNA base pairs was further supported by the variations in CT-DNA base stacking observed in circular dichroic spectrum measurements and the rise in viscosity of the CT-DNA solution. The interaction energy between Dithianon and the DNA was primarily due to hydrophobic Van der Waals interactions. This study offers a comprehensive understanding of how dithianon interacts with CT-DNA, providing insights into the toxic effects of the fungicide.

Myocardial infarction (MI) is a major contributor to death in contemporary society, and this mechanism involves n6-methyladenosine (m⁶A) modification. In this study, we studied the m⁶A mechanisms involved in MI. For this purpose, an H9C2 cell MI model and MI rat model were developed. Cell Counting Kit-8 was applied to determine the effect of granzyme K (GZMK) differential expression on cell survival. In addition, 2,3,5-triphenyl tetrazolium chloride, hematoxylin-eosin, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining, and enzyme-linked immunosorbent assay were performed to determine the effect of GZMK differential expression on myocardial injury markers, apoptosis, and inflammatory factors. The m⁶A-modification effect between Wilms' tumor 1-associate protein (WTAP) and GZMK was detected via methylated RNA immunoprecipitation. The expression of WTAP and GZMK in MI model cardiomyocytes was measured by quantitative reverse transcription polymerase chain reaction and western blotting. WTAP and GZMK were found to be highly expressed in MI H9C2 cells. Moreover, GZMK knockdown boosted cardiomyocyte proliferation, dampened the markers of myocardial injury and inflammation, and injured apoptosis in the MI model, whereas GZMK overexpression aggravated cardiomyocyte MI injury. GZMK was positively mediated by WTAP in cardiomyocytes and was subjected to WTAP-mediated m⁶A modification. The low expression of GZMK reduced the MI area, attenuated myocardial tissue damage and inflammation, and arrested cardiomyocyte apoptosis in the MI rats. Thus, for the first time, we demonstrated that GZMK was modified by WTAP via m⁶A modification, which promoted its expression in MI, thereby aggravating MI-induced myocardial injury.

Retinoblastoma (RB) arising from the retina's primitive neural precursor cells is a highly aggressive pediatric ocular malignancy. Ubiquitin-conjugating enzyme E2C (UBE2C) is implicated in carcinogenesis, but its role and mechanism in RB remain unexplored. Here, we aimed to explore the effect of UBE2C and its regulatory mechanism in an N6-methyladenosine (m⁶A) modification method in RB. The expression of UBE2C and methyltransferase-like 3 (METTL3) was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. After using shRNA and overexpression vectors to modulate the expression of UBE2C and METTL3 in RB cells, cell viability, proliferation, apoptosis, and phosphoinositide 3-kinase-protein kinase B (PI3K-AKT) pathway activity were assessed via cell counting kit-8, 5-ethynyl-2'-deoxyuridine, flow cytometry, and Western blotting assays, respectively. The correlation between METTL3 and UBE2C in RB cells was verified by qRT-PCR, Western blotting, methylated RNA immunoprecipitation, mRNA stability assays. The results showed that UBE2C with high expression in RB enhanced RB cell survival via elevating cell viability and proliferation, as well as suppressing apoptosis. UBE2C activated the PI3K-AKT pathway by promoting the PI3K and AKT proteins. METTL3 upregulated UBE2C expression and enhanced UBE2C mRNA stability via m⁶A modification. In addition, upregulating METTL3 partly restored the negative effects of UBE2C downregulation on RB cells. In conclusion, METTL3 drives UBE2C overexpression through m⁶A modification, thereby activating the PI3K-AKT pathway to foster RB progression. This study identifies the METTL3/UBE2C/PI3K-AKT axis as a novel therapeutic target for RB.

Tail fat weight is a key economic trait in fat-tailed sheep; reducing tail fat deposition is of significant importance for improving the economic efficiency of sheep farming. In this article, we measured the live weight before slaughter, tail fat weight, and carcass weight of Hu male sheep at 6 months of age and performed the descriptive statistical analysis. The results indicated the coefficient of variation of tail fat-related-traits ranged from 25% to 50%. Simultaneously, we selected IGFBP3 and TUSC5 as candidate genes based on their close association with fat deposition. Target regions were amplified using gene-specific primers in PCR, followed by Sanger sequencing of PCR products to identify genetic variants. Polymorphisms were subsequently validated using the KASPar genotyping assay. Finally, quantitative reverse transcription PCR (qRT-PCR) was performed to determine the expression levels of IGFBP3 and TUSC5. Our findings revealed a missense mutation (g.83695349 C>T) in exon 1 of the IGFBP3 gene and a synonymous mutation (g.41771645 C>T) in exon 2 of the TUSC5 gene. Association analysis showed that these mutations were significantly correlated (p < 0.05) with tail fat weight traits. Moreover, the tail fat weight of the mutant genotypes (CT and TT) was significantly reduced compared with that of the CC genotype, suggesting that the gene may exert a negative regulatory effect on this trait, thereby leading to the reduction of tail fat weight. Furthermore, the genotype combinations showed a significant relationship with tail fat traits. Moreover, qRT-PCR results showed that TUSC5 and IGFBP3 genes were expressed in all experimental tissues of Hu sheep, and the highest expression was observed in tail fat compared with other tissues (heart, liver, spleen, lung, kidney, rumen, duodenum, muscle, and lymph). Notably, their expression levels were significantly lower in the large-tail fat group than in the small-tail fat group. Overall, these results will provide novel candidate variation for reducing tail fat deposition in sheep breeding practice.

Why plants need fertilization to produce seeds has long been discussed. We recently identified a new specialized tissue required for seed formation at the ovule's chalazal end, showing the final form of the phloem end and supporting its transport function; however, it is blocked by callose deposition. Callose is removed after central cell fertilization (open state), allowing nutrients to be transported to the seed. However, if fertilization fails, callose deposition persists (closed state), preventing the tissue from transporting nutrients. A β-1,3-glucanase gene, AtBG_ppap, was identified, and the AtBG_ppap mutant showed the closed state, producing smaller seeds due to incomplete callose degradation. Contrarily, the AtBG_ppap overexpression line produced larger seeds due to continuous callose degradation, showing that the tissue is the "gateway" for the seed nutrients.

Autoimmune and inflammatory diseases are rising globally yet widely effective therapies remain elusive. Most treatments have limited efficacy, significant potential side effects, or eventually lose response, underscoring the urgent need for new therapeutic approaches. We recently discovered that ETS2, a transcription factor, functions as a master regulator of macrophage-driven inflammation-and is causally linked to the pathogenesis of multiple inflammatory diseases via human genetics. The pleotropic inflammatory effects of ETS2 included upregulation of many cytokines that are individually targeted by current disease therapies, including TNFα, IL-23, IL1β, and TNF-like ligand 1A signaling. With the move toward combination treatment-to maximize efficacy-targeting ETS2 presents a unique opportunity to potentially induce a broad therapeutic effect. However, there will be multiple challenges to overcome since direct ETS2 inhibition is unlikely to be feasible. Here, we discuss these challenges and other unanswered questions about the central role that ETS2 plays in macrophage inflammation.

STING, an endoplasmic reticulum-localized protein with multiple transmembrane domains, has been implicated in colorectal cancer (CRC) development. This study investigated the association between STING rs7380824 polymorphism and CRC susceptibility using both bioinformatics analysis and a case-control study. Bioinformatics predictions from SIFT and PolyPhen indicated that the rs7380824 variant, which results in an amino acid substitution from arginine (R) to glutamine (Q) at position 293, is likely to be deleterious, with a SIFT score of 0.000 and a PolyPhen score of 0.999. A total of 870 CRC patients and 870 healthy controls were genotyped using polymerase chain reaction-restriction fragment length polymorphism. Logistic regression analysis demonstrated that individuals carrying the CT and TT genotypes had an increased risk of CRC with OR (95% CI) of 1.564 (1.115-2.192) and 1.551 (1.271-1.893), respectively. Stratified analysis showed that the rs7380824 C > T variant increased CRC risk in all age and gender groups. Furthermore, non-smokers with the CT or TT genotype had a higher CRC risk (OR = 1.661, 95% CI: 1.333-2.071, p < 0.001), while no significant association was observed among smokers (p = 0.238). Similarly, non-drinkers carrying the CT or TT genotype showed an increased CRC risk (OR = 1.746, 95% CI: 1.395-2.185, p < 0.001), whereas no significant difference was detected among drinkers (p = 0.265). This study identifies STING rs7380824 polymorphism as a significant contributor to CRC susceptibility, with bioinformatics predictions and case-control analysis confirming its deleterious impact and the association with increased CRC risk. In addition, these findings underscore the interplay between genetic and environmental factors in CRC development, highlighting STING's potential as a genetic biomarker for CRC risk assessment in the Chinese population.