Search Results (5,402)

DNA viruses rely extensively on host cellular machinery, including replication factors and transcriptional systems, to persist after infection. These mechanisms make studying and targeting DNA viral proteins challenging, as they also play key roles in mammalian processes. Traditional strategies include CRISPR-mediated gene disruption and small interfering RNA (siRNA) to target host proteins. However, Proteolysis Targeting Chimeras (PROTACs) offer a novel strategy by enabling the selective and rapid degradation of specific viral or host proteins involved in the DNA viral lifecycle. PROTACs are heterobifunctional molecules composed of three key components: a ligand that binds the target protein, a chemical linker, and a ligand that recruits an E3 ubiquitin ligase. By simultaneously binding both the target protein and the E3 ligase, PROTACs form a ternary complex. This proximity enables the E3 ligase to ubiquitinate the target protein, marking it for recognition and subsequent degradation by the intracellular proteasome. This approach represents a promising avenue for targeting previously undruggable proteins and improving therapeutic outcomes in virus-associated malignancies. In this perspective, we describe studies that use PROTACs as tools to modulate host proteins to investigate DNA viral processes with temporal control of host protein expression, as well as the use of PROTACs as antivirals to directly target DNA viral proteins. We also provide a detailed chart summarizing known host-targeting PROTACs and their potential applications across different stages of DNA viral lifecycles, highlighting opportunities for future DNA virus research. Full article

Radiation-induced biological responses emerge through complex interactions across multiple biological scales, ranging from molecular damage to tissue remodeling and organism-level outcomes. Although traditional radiobiology has primarily focused on DNA damage and linear dose–response relationships, increasing evidence suggests that radiation responses are highly context-dependent and cannot be fully explained by genomic alterations alone. In particular, low-dose and chronic radiation exposures often induce biological effects that involve dynamic regulatory processes beyond direct mutational burden. The narrative review proposes a conceptual multiscale framework for predictive radiobiology that integrates genomic damage, post-transcriptional regulation, network rewiring, and tissue microenvironmental interactions. Within this framework, “predictive radiobiology” refers to the integrative prediction of radiation-induced outcomes, including radiosensitivity, tissue remodeling, fibrosis progression, therapeutic response, and long-term carcinogenic risk. We discuss how radiation-induced signaling extends beyond DNA double-strand breaks to include RNA-binding protein-mediated regulation, adaptive network responses, and extracellular matrix-dependent cellular plasticity. Recent advances in multi-omics, single-cell analysis, spatial biology, and three-dimensional organotypic models have revealed that radiation responses are governed by interconnected molecular and tissue-level processes. Furthermore, artificial intelligence and systems-level computational approaches provide new opportunities for modeling non-linear and context-dependent radiation effects across biological scales. We further discuss current limitations, including data integration challenges, reproducibility issues, and the translational gap between experimental models and clinical applications. Collectively, this conceptual framework highlights the need for integrative and multiscale approaches to improve mechanistic understanding and predictive modeling in modern radiobiology. Full article

A series of critical interactions within the viral core between viral RNA (vRNA) and HIV-1 Integrase (IN) has previously been reported. In these studies, contact points between vRNA and IN were identified using RNA-seq and MS-based protein foot-printing approaches. Several IN amino acids located in its C-terminal domain (CTD) were found to be essential for vRNA binding, and their alanine substitution severely impacted the correct morphogenesis of the mature viral core. Here, we have used the TAR element to extend these studies by performing a comprehensive mapping of the interaction by deploying RNA crosslinking and NMR methodologies. Together, these approaches were able to identify additional contact points between the TAR vRNA and IN. Our results reveal several new basic amino acids located in the IN CTD critical for the vRNA-IN interaction, viral replication and correct morphology of the mature viral core. Full article

The senescence-associated secretory phenotype (SASP) contributes to various age-related pathologies. Methyl caffeate exhibits strong SASP-inhibitory activity; however, its molecular targets and the precise mechanisms underlying its effects remain unclear. Therefore, in this study, we performed affinity chromatography using methyl caffeate-immobilized beads to identify its intracellular binding proteins. The functional roles of the identified target were validated via knockdown experiments, assessment of SASP factor (interleukin [IL]-6 and IL-8) expression at the mRNA and secretion levels, and analysis of nuclear factor-κB and p38 mitogen-activated protein kinase signaling pathways. IQ motif-containing GTPase-activating protein 1 (IQGAP1) was identified as a methyl caffeate-binding partner. IQGAP1 knockdown significantly reduced IL-6 and IL-8 expression levels, mimicking the effects of methyl caffeate treatment. Furthermore, IQGAP1 depletion suppressed nuclear factor-κB activation and p38 phosphorylation. Overall, this study identified IQGAP1 as a critical scaffold protein essential for SASP induction and a target of methyl caffeate. Our findings provide key insights into SASP regulation, facilitating the development of SASP-modulating therapeutics targeting specific IQGAP1 domains. Full article

Background: Esophageal squamous cell carcinoma (ESCA) represents one of the most common aggressive malignancies worldwide. Insulin-like growth factor binding protein 1 (IGFBP1), a typical member of the IGF superfamily, is closely linked to adverse prognosis in numerous cancers. Up to now, little is known about its functional relevance to cell migration and tumor progression in ESCA. This work focuses on clarifying the relationship between IGFBP1 expression and the progression and migratory characteristics of ESCA. Methods: mRNA expression profiles from ESCA patients were obtained from the TCGA and GEO databases. Differential expression analysis was performed using R software(version 4.2.2), followed by an intersection of DEGs between datasets. The STRING database was applied to establish PPI networks. Cytoscape software(Version 3.7.2) was then used for visual presentation and hub gene identification. IGFBP1 expression was validated in ESCA tissues versus adjacent normal tissues. Prognostic correlation was assessed using GEPIA, while diagnostic and predictive values were evaluated through ROC analysis and Cox regression. Genetic alterations of IGFBP1 were analyzed via cBioPortal. Immune cell infiltration patterns were investigated using TIMER. Functional enrichment analyses (GO, KEGG) were performed on IGFBP1-associated DEGs. In the in vitro experiments, esophageal cancer cell lines (such as Eca109 and TE-1) and normal human esophageal epithelial cell lines (such as HEEC) were selected. The transcriptional level of IGFBP1 was examined using RT-qPCR, while Western blot analysis was conducted to validate its protein expression changes. Changes in the proliferative capacity of cancer cells after IGFBP1 silencing were detected by the CCK-8 assay, and cell migration capacity was determined via wound scratch assays to clarify the related biological effects. Results: Overall, 2870 DEGs were screened from the GEO database, 153 DEGs were screened from the TCGA database, and 34 genes were found to be common to both databases; 10 core genes were screened from the PPI network. IGFBP1 was abnormally expressed in esophageal cancer. Cox regression confirmed that IGFBP1 is an independent risk factor, and prognostic analysis indicated that IGFBP1 is closely associated with poor prognosis. Gene mutation analysis showed that amplification mutations are the most common type of IGFBP1 gene mutation, and genetic alterations in IGFBP1 in ESCA patients are significantly associated with overall survival (OS) (p = 0.0002568). GO analysis indicated that IGFBP1-related differentially expressed genes were enriched in organic anion transport, epidermal development, apical cell components, and metal ion transmembrane transporter activity. Pathway enrichment based on the KEGG database illustrated the main enrichment of target genes in neuroactive ligand–receptor interactions, calcium signaling and cAMP signaling pathways. Additionally, remarkable differences in immune cell infiltration were observed between IGFBP1 high-expression and low-expression subgroups through tumor immune profiling. IGFBP1 expression differed significantly between esophageal cancer cells and normal esophageal epithelial cells, as detected by RT-qPCR (p < 0.05). Moreover, knockdown of IGFBP1 markedly inhibited the proliferation (p < 0.05) and migration abilities (p < 0.05) of TE-1 and Eca109 cells. Conversely, IGFBP1 overexpression facilitated these cellular processes. Conclusions: As a key oncogenic driver for ESCA, IGFBP1 may participate in the oncogenesis of ESCA, possibly influencing clinical outcomes via IGF signaling and the tumor microenvironment. Its dual functions in tumor and immune systems suggest it might be a candidate for ESCA immunotherapy research. Full article

RNA-binding proteins (RBPs) are essential regulators of all aspects of RNA metabolism, including splicing, stability, localisation, translation, and degradation. Through their ability to recognise specific cis-elements in target transcripts, often via RNA-recognition motifs or other conserved domains, RBPs enable rapid cellular adaptation to stress and maintain proteostasis, particularly in post-mitotic tissues with limited transcriptional flexibility. Accumulating evidence positions RBPs as both modulators and drivers of the molecular hallmarks of ageing, including genomic instability, loss of proteostasis, mitochondrial dysfunction, cellular senescence, and chronic inflammation. This review synthesises peer-reviewed studies on the multifaceted roles of RNA-binding proteins in organismal ageing and age-related diseases. Key themes include the tissue- and age-dependent changes in expression of turnover and translation regulatory RBPs such as HuR (ELAVL1), AUF1 (HNRNPD), TIA-1, and tristetraprolin (ZFP36), which alter the stability of mRNAs encoding cell-cycle regulators, pro-inflammatory cytokines, and stress-response proteins. Systematic downregulation of core splicing factors, including PTBP1 and several heterogeneous nuclear ribonucleoproteins, drives widespread senescence-associated splicing alterations in pathways governing cell division, autophagy, DNA repair, and mitochondrial function, suggesting a causal contribution to the senescent phenotype. Prion-like RBPs such as TDP-43 and FUS exhibit age-dependent mislocalisation, nuclear depletion, and cytoplasmic aggregation, contributing to splicing defects, impaired RNA transport, and neurodegeneration in amyotrophic lateral sclerosis, frontotemporal dementia, and limbic-predominant age-related TDP-43 encephalopathy. Interactions between RBPs and non-coding RNAs, together with disrupted liquid–liquid phase separation dynamics, further exacerbate age-related decline. By integrating mechanistic studies from cellular and animal models with observations in human cohorts, this review underscores RBPs as central nodes linking multiple ageing hallmarks and highlights their potential as biomarkers and therapeutic targets to promote healthy ageing. Limitations of current models and priorities for future translational research are discussed. Full article

The melon fly, Zeugodacus cucurbitae (Coquillett), is a globally significant agricultural pest causing substantial economic losses. Odorant-binding proteins (OBPs) are critical of the insect olfactory system, yet their specific physiological functions in Z. cucurbitae remain largely uncharacterized. In this study, we functionally characterized ZcucOBP14 and investigated its putative involvement in host chemoreception and insecticide tolerance. Sequence alignment and phylogenetic analysis indicated that ZcucOBP14 belongs to the Minus-C OBP subfamily, and quantitative reverse transcription PCR (RT-qPCR) showed that it was predominantly expressed in both the head and abdomen. Fluorescence binding assays revealed that ZcucOBP14 exhibited broad binding affinity to 11 host plant volatiles, three sex pheromones, and two insecticides. Subsequent electroantennography (EAG) and behavioral bioassays identified isopulegol, 1-hexanol, linalool, and α-pinene as key ligands regulating the behavioral responses of Z. cucurbitae. RNA interference (RNAi)-mediated knockdown of ZcucOBP14 significantly reduced EAG responses to key ligands, eliminated behavioral preference, and increased insecticide-induced mortality by 20%. Molecular docking further identified that Tyr71, Ile67, Trp50, Val107, Phe116 and Leu70 were critical residues involved in ligand interactions. Collectively, these findings highlight the indispensable role of ZcucOBP14 in olfactory perception and its contribution to insecticide tolerance, laying a solid theoretical foundation for the development of novel behavior-modifying agents, attractants, and optimized integrated pest management (IPM) strategies against this pest. Full article

Background/Objectives: As important post-transcriptional and epigenetic regulators of gene expression, miRNAs play a pivotal role in modulating host–virus interactions. While prior reviews have addressed either direct miRNA–HIV genome interactions or miRNA-mediated immune modulation in isolation, the integrated dual functionality of these molecules has not been systematically characterized. This review aimed to comprehensively explore how miRNAs that target the HIV-1 genome simultaneously modulate key innate and adaptive host immune signaling pathways. The conceptual novelty of this study is determined not by the identification of previously unknown miRNA-target gene pairs, but by the systemic integration of two regulatory levels (direct inhibition of the viral genome and modulation of the host cell immune signaling pathways) within a unified analytical framework. Such an integrated approach reveals a proviral regulatory network that remains non-obvious when each of these levels is examined separately. Methods: A narrative review was conducted using PubMed, Scopus, Web of Science, and Google Scholar (all years through 2025). In Stage 1, publications reporting experimentally confirmed interactions between host miRNAs and the HIV-1 genome were identified, yielding a curated set of 15 miRNAs. In Stage 2, target genes for each miRNA were retrieved from miRTarBase, TarBase (experimentally validated) and TargetScan 8.0 (in silico predicted). In Stage 3, target genes were manually mapped to key immune signaling pathways (TLR, NF-κB, JAK-STAT). In Stage 4, targeted literature searches were performed for each miRNA–target gene pair to identify direct experimental evidence of interaction. All stages were performed by two independent researchers, with discrepancies resolved by a third. Results: Fifteen host miRNAs with experimentally confirmed binding to the HIV-1 genome were identified, targeting viral genes including nef, pol, vpr, gag, env, vif, and the 3′-UTR. Thirteen of these miRNAs were found to regulate components of major immune pathways. miR-92a-3p, miR-29a/b-3p, miR-150-5p, and miR-125b-5p emerged as the most pleiotropic regulators, simultaneously suppressing TLR signaling (TLR3, TLR7, TLR8, MyD88, TRAF3/6, IRAK1/4), NF-κB components (REL, RELA, NFKB1), JAK-STAT effectors (STAT1–3, STAT5A/B, JAK2), and negative regulators of cytokine signaling (SOCS and PIAS family proteins). miR-133b and miR-196b-5p were found to selectively regulate SOCS/PIAS proteins without involvement in other analyzed pathways, suggesting potential for selective therapeutic targeting. Conclusions: The analyzed miRNAs exhibit functional dualism, acting as direct post-transcriptional suppressors of the HIV-1 genome while simultaneously functioning as epigenetic modulators of host immune signaling. These two modes of action are not independent but together form a conceptual framework of a self-reinforcing proviral regulatory network that, based on the synthesis of published evidence, is proposed to promote viral latency and immune evasion. The identified miRNAs represent promising, albeit complex, targets for novel therapeutic strategies aimed at eliminating latent HIV reservoirs. Full article

To clarify the cellular origin of matrix metalloproteinase-9 (MMP9) and explore targeted research, we utilized single-cell RNA sequencing analysis, which revealed that MMP9 is predominantly enriched in specific macrophages within the activated B-cell-like (ABC) subtype. Guided by this target information, we applied a generative AI pipeline incorporating RFdiffusion, ProteinMPNN, and AlphaFold to de novo design protein binders targeting the hemopexin (PEX) domain of MMP9. ELISA experiments confirmed the in vitro binding capability of these designs; among them, MMP9-30 displayed the strongest binding, with an apparent EC50 of approximately 1.1 μM, followed by MMP9-34, while MMP9-97 showed the weakest interaction. This study successfully integrates single-cell sequencing with AI-assisted protein design, providing a preliminary exploratory framework for subsequent MMP9-targeted research and protein binder development. Full article

Background: Triple-negative breast cancer (TNBC) remains a clinical challenge due to its aggressive nature and the frequent emergence of therapeutic resistance. While the role of protein-coding genes in DNA repair is well-documented, the regulatory contributions of the non-coding genome, specifically long intergenic non-coding RNAs (lincRNAs), remain largely undefined. Objectives: In this study, we characterize the biological significance of LincRNA-BC7, a novel transcript identified within the breast cancer field effect. Methods: Through a combined in silico and in vitro approach, we investigated the transcriptional dynamics of the LincRNA-BC7/miR-663a/BRCA1 axis in response to the PARP inhibitor, Olaparib. Results: Our results demonstrate that Olaparib induces selective cytotoxicity in BRCA1-deficient MDA-MB-231 cells while sparing non-cancerous HEK293 cells, a response accompanied by a significant downregulation of LincRNA-BC7 and a reciprocal upregulation of BRCA1. Bioinformatics analysis through BLASTN, miRBase, and KEGG revealed that LincRNA-BC7 contains highly complementary binding sites for miR-663a, suggesting it functions as a competing endogenous RNA (ceRNA) or “molecular sponge.” Conclusions: By sequestering miR-663a, LincRNA-BC7 appears to modulate the expression of critical signaling nodes within the PI3K-AKT and TP53 pathways, thereby influencing cellular sensitivity to DNA-damaging agents. These findings suggest that LincRNA-BC7 is a key determinant of the aggressive TNBC phenotype and the response to PARP inhibition. Our study establishes the LincRNA-BC7/miR-663a axis as a novel biomarker for precision risk stratification and a promising therapeutic target to enhance treatment outcomes in BRCA1-associated breast cancers. Full article

Background/Objectives: The bean beetle (Callosobruchus maculatus) exhibits population density-dependent plasticity in the terminal oocyte maturation rate. DNA methyltransferase 1 (DNMT1) plays a conserved function in reproduction that is independent of DNA methylation. However, whether DNMT1 is involved in the population density-dependent reproductive plasticity of bean beetles remains unclear. Methods: Two and twenty pairs of beetles were reared with approximately 100 seeds per bottle to establish a low-density population and a high-density population, respectively. Quantitative real-time PCR was used to unveil the mRNA levels of DNMT1, MBD2/3, and insulin-like peptides (ILPs). RNA interference was used to determine the function of DNMT1 and MBD2/3 in terminal oocyte development. The length of terminal oocytes was measured under a microscope. Results: Individuals reared under high-population-density conditions showed a faster terminal oocyte maturation rate compared to those under low-density conditions. The bean beetle genome encodes DNMT1 but lacks DNMT3, and only a single methyl-DNA-binding domain protein (MBD2/3) was identified. Population density could modulate the expression levels of both DNMT1 and MBD2/3. RNA interference (RNAi)-mediated knockdown demonstrated that suppressing either DNMT1 or MBD2/3 significantly reduced the terminal oocyte maturation rate. Moreover, silencing DNMT1 and MBD2/3 resulted in decreased expression of ILP3 and all ILPs in the fat body, respectively. ILPs are known to be involved in regulating terminal oocyte development. Conclusions: Taken together, these findings suggest that DNMT1 and MBD2/3 modulate the population density-dependent terminal oocyte maturation rate in the bean beetle by influencing the expression of ILPs. Full article

The epicardium is an embryonic tissue layer essential for heart morphogenesis, providing progenitor cells and regulatory signals that support myocardial growth and coronary vessel formation. Epicardial cells arise from the proepicardium (PE) and spread over the myocardium to form the embryonic epicardium (EE), a transition that requires tight coordination between proliferation, migration, and lineage priming. However, the molecular mechanisms controlling this developmental timing remain incompletely understood. Here, we identify Trim71 as a key regulator of epicardial cell behaviour during the PE-to-EE transition. Trim71 is enriched in the PE and subsequently downregulated as cells acquire migratory competence. Functional analyses show that loss of Trim71 function decreases proliferation while promoting migration, as well as inducing the expression of epicardial commitment markers, suggesting that Trim71 is a controller of a progenitor-like state. We further demonstrate that Trim71 is necessary for these processes through a reciprocal feedback loop with the microRNAs let-7c and miR-30c. Our findings establish Trim71 as a temporal gatekeeper that coordinates the balance between progenitor maintenance and migration during early epicardial development. This Trim71-miRNAs axis constitutes a novel post-transcriptional layer of regulation that ensures the correct timing of epicardium development during cardiogenesis. Full article

Rheumatoid arthritis (RA) is a systemic immune-related disease characterized by chronic synovial inflammation and progressive joint destruction. However, the molecular mechanisms and diagnostic biomarkers underlying RA remain unclear. In this study, we aimed to identify potential biomarkers for clinical diagnosis of RA and to investigate their association with immune infiltration. By integrating differentially expressed genes analysis (DEGs) and weighted gene co-expression network analysis (WGCNA), we identified PSMB9 as a hub gene associated with RA. Gene set enrichment analysis (GSEA) and immune infiltration analysis revealed a strong association between RA and macrophage infiltration. Single-cell RNA sequencing datasets also suggest that PSMB9 is not only highly expressed in macrophage but is also present in synovial cells. We employed cellular thermal shift assay (CETSA) combined with Western blot to validate the interaction between sinomenine (SIN) and the target protein. CETSA results demonstrated that, compared with the control group, SIN increased the thermal stability of PSMB9, suggesting direct binding between the two. Western blot experiments further confirmed that PSMB9 protein expression was significantly downregulated following SIN treatment. PSMB9 may serve as potential diagnostic biomarker and therapeutic targets for RA. Moreover, our data suggest SIN may exert anti-inflammatory effects through regulation of PSMB9. This study also provides an additional insight into the underlying mechanisms involved in the progression of RA and discover a new molecular target for SIN. Full article

Neuritogenesis is essential for neuronal development and circuit formation. Although cAMP signaling downstream of Gs-coupled receptors is considered pro-neuritogenic, activation of these Gs-coupled receptors can produce divergent cellular outcomes. We previously showed that prostaglandin E₂ (PGE₂) induces neurite outgrowth in NSC-34 motor neuron-like cells predominantly through Gs-coupled E-prostanoid receptor 2 (EP2) signaling. The I-prostanoid receptor (IP) is also Gs-coupled, but whether its ligand PGI₂ elicits neuritogenesis remains unclear. Here, we compare the neuritogenic and signaling responses to PGE₂ and PGI₂ in NSC-34 cells. PGE₂ and the EP2 agonist butaprost increased the proportion of neurite-bearing cells, whereas PGI₂ and the IP agonist beraprost had no effect. PGI₂ and PGE₂ induced comparable cAMP accumulation and protein kinase A substrate phosphorylation, and elicited peak cAMP response element binding protein (CREB) phosphorylation at 1 h. However, only PGE₂ maintained significant CREB phosphorylation at 3–6 h. RNA sequencing at 4 h revealed broadly concordant transcriptional responses, while direct comparison identified Fst as the only gene expressed at higher levels under PGE₂ than under PGI₂. These findings suggest that the temporal profile of CREB phosphorylation, rather than the magnitude of early cAMP-PKA signaling, may be associated with differences in neuritogenic outcomes of Gs-coupled prostanoid signaling. Full article

Background/Objectives: The σ factor of bacterial RNA polymerase (RNAP) directs promoter recognition, recruits RNAP to initiate transcription, and is released from the elongation complex to participate in subsequent rounds of initiation. However, the dynamic recycling mechanism of the primary σ factor, σ⁷⁰ (RpoD), during transcription in Escherichia coli remains poorly understood. Methods: We employed in vivo and in vitro interaction assays to screen for σ⁷⁰-interacting partners under different growth conditions. Protein localization studies were performed using fluorescence microscopy. The transcriptomic profile of ΔclpB, ΔdnaK, ΔhtpG, or ΔyhgF mutant was assessed by RNA-seq. Results: The molecular chaperones ClpB, DnaK, HtpG, and the RNA-binding protein YhgF interacts with RpoD both in vivo and in vitro, and the interaction in vivo is growth medium-dependent (LB vs. ABTGcasa). During exponential growth, each of these proteins co-localizes with the nucleoid. The transcriptome profile in ΔclpB, ΔhtpG or ΔyhgF mutant is mutant-specific to some extent; differentially expressed genes (DEGs) associated with amino acid metabolism and lipopolysaccharide biosynthesis are down-regulated in ΔclpB, ΔhtpG or ΔyhgF mutant in a manner that is growth medium-dependent, in agreement with the medium-dependent interaction of RpoD with the chaperones and YhgF. In contrast, the absence of DnaK resulted in delays to initiation of replication with a slow growth, and decreases cell motility, accompanied by down-regulated flagellar assembly and up-regulated amino acid metabolism genes. In summary, ClpB, DnaK, HtpG, and YhgF may regulate transcription by directly interacting with σ⁷⁰. The σ factor recycling guides global transcription to select genes for transcription and subsequently allows cells to cope with the changing environments by responding to the nutrient level as a signal. Full article