Potato mop-top virus (PMTV) is a significant pathogen causing potato "spraing" disease worldwide. The PMTV 8K protein functions as a weak viral suppressor of RNA silencing (VSR), has viroporin activity and plays a role in pathogenicity by promoting viral long-distance movement and modulating host responses. Uniquely, PMTV can establish systemic infection in the absence of the 8K protein, though the infection is slightly delayed. To elucidate the molecular mechanisms underlying PMTV-host interactions, we conducted comprehensive RNA-seq analysis comparing wild-type PMTV with a mutant lacking the 8K gene (PMTV-Δ8K) in Nicotiana benthamiana. Our transcriptomic analysis shows that wild-type PMTV and PMTV-Δ8K elicit largely distinct transcriptional responses in the host, with more unique than shared differentially expressed genes. The analysis also revealed extensive reprogramming of metabolic pathways, stress responses, and defense mechanisms. Notably, wild-type PMTV induced more defense-related transcription factors, including 27 WRKY genes compared to 8 in PMTV-Δ8K infections. RNA silencing pathway genes displayed distinct expression patterns, with AGO2, RDR1, and AGO-MEL1 showing notably enhanced upregulation (up to 9.7-fold) in PMTV-Δ8K infections. Functional analysis identified chloroplast-associated genes GNS2, CHUP1, and KIN5l as host restriction factors. Virus-induced gene silencing experiments confirmed that GNS2 and CHUP1 restrict viral accumulation under both infection scenarios (wild-type PMTV and PMTV-Δ8K), while localization studies revealed that TGB2 protein and GNS2 co-localize at chloroplast structures. These findings provide insights into PMTV pathogenesis, suggest that 8K is a multifunctional protein operating through diverse mechanisms, and advance understanding of viral suppression strategies.

A positive feedback loop between the lncRNA TaHTMAR and TaHGSNAT is essential for thermo-sensitive male fertility in wheat.

P2A-mediated Co-translation Bypasses GESENI, a Cryptic Gene Silencing System in Arabidopsis Sperm Cells.

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with a poor prognosis and increasing global incidence. Although the epigenetic regulator plant homeodomain finger protein 1 (PHF1) is known for its transcriptional silencing function in cancer, its role in PDAC progression and translational regulation remains largely unexplored. Here, we report that PHF1 is significantly upregulated in PDAC and promotes the proliferation, migration, and invasion of PDAC cells. Mechanistically, PHF1 physically interacts with the fibrillarin (FBL)/NOP56/NOP58 snoRNP complex, facilitating its assembly and enhancing the internal ribosome entry site (IRES)‐dependent translation of Snail. Depletion of PHF1 reduces Snail levels, leading to ferroptosis sensitization in KRAS‐mutated PDAC cells. Additionally, PHF1 knockdown markedly reduces overall tumor burden in Kras‐mutated mice. In conclusion, our findings identify PHF1 as an oncogene that promotes PDAC progression and demonstrate that its inhibition induces ferroptosis via suppression of IRES‐dependent Snail translation. Thus, our findings reveal a previously unrecognized translational regulatory role of PHF1 and suggest its targeting as a promising therapeutic strategy for PDAC.

Gene silencing meets chemotherapy: A dual topical strategy using lipid nanoparticles against squamous cell carcinoma.

ABSTRACTBackgroundSarcopenic obesity, where excess body fat coexists with reduced muscle mass and function, is becoming increasingly common in ageing populations and contributes to poor physical and metabolic health. Although adipose tissue–secreted factors are implicated in muscle decline, the specific mechanisms remain unclear. Extracellular vesicles (EVs), which carry regulatory cargo such as microRNAs (miRNAs) between cells, may play a key role in this adipose–muscle communication.MethodsEVs were isolated from adipose‐conditioned media (ACM) collected from lean and non‐lean human donors using ultracentrifugation. Donors were grouped by BMI (lean: 20.7–24.4; non‐lean: 25.3–39.3) and age (younger: 31–56 years; older: 60–84 years). EVs were characterised using nanoparticle tracking analysis (NTA), ExoView, nanoscale flow cytometry (CytoFLEX Nano) and transmission electron microscopy (TEM). Primary human myoblasts were differentiated into myotubes and treated for 24 h with lean or non‐lean EVs (1.3 × 109 particles/mL) or left untreated. Myotube thickness was measured by immunofluorescence microscopy. Transcriptomic changes were assessed by bulk RNA sequencing. EV miRNA cargo was profiled by small RNA‐seq and validated by qPCR. The role of miR‐150‐5p was tested using antagomir inhibition.ResultsNon‐lean EVs significantly reduced myotube thickness in older adult‐derived myotubes compared to both untreated controls (8.7 ± 1.66 μm vs. 12.4 ± 1.72 μm, p < 0.01) and lean EV‐treated myotubes (8.7 ± 1.66 μm vs. 13.2 ± 3.84 μm, p < 0.05), indicating a donor BMI‐specific effect. This atrophy was restricted to myotubes derived from older donors. The same experimental approach was applied to younger adult‐derived myotubes; no reduction in myotube thickness was observed.MAFbx expression was significantly increased in response to non‐lean EVs (p < 0.05). RNA‐seq revealed 471 differentially expressed genes (DEGs) in EV‐treated versus untreated cells and 293 DEGs between lean and non‐lean EV conditions, with enrichment in inflammatory (TNF and IL1B), oxidative stress, mitochondrial and chromatin pathways. Small RNA‐seq identified seven differentially expressed miRNAs (annotated using miRBase release 22.1), including miR‐150‐5p and miR‐193b‐5p, both significantly upregulated in non‐lean EVs and validated by qPCR. Inhibiting miR‐150‐5p partially rescued myotube thickness (10.5 ± 1.37 μm vs. 8.7 ± 1.66 μm, p < 0.05) and reduced MAFbx expression.ConclusionsEVs from non‐lean adipose tissue drive muscle atrophy and transcriptional changes in an age‐dependent manner. These effects are partially mediated by miR‐150‐5p, highlighting a mechanistic role for EV cargo in adipose‐muscle signalling. Targeting EV‐derived miRNAs may offer a novel strategy to combat muscle loss in obesity and ageing.

Small interfering RNAs (siRNAs) offer significant therapeutic potential; however, extrahepatic applications, particularly to the skin, remain a challenge. Limited work has explored siRNA therapies for the skin, the largest organ in the human body, where dermatological conditions affect over one-third of the population worldwide. The skin's external location makes it easily accessible for direct, local administration. Here, we present the in vivo intradermal delivery of therapeutic siRNAs into a porcine model whose skin structure most closely resembles that of human skin, demonstrating functional, and sustained gene silencing. We characterize two siRNA conjugates in human ex vivo and porcine in vivo skin models, showing that increased hydrophobicity significantly enhances skin retention and efficacy of siRNAs. Using a validated JAK1-targeting compound, we demonstrate that local delivery of siRNA enables accumulation across multiple cell types and suppression of JAK1-dependent inflammatory pathway in human skin ex vivo. In porcine models, intradermal injections result in prolonged skin siRNA retention for more than eight weeks, limited systemic tissue exposure, and sustained gene silencing for at least one month. These results underscore the importance of tailored siRNA conjugate design for achieving optimal skin biodistribution and therapeutic efficacy, providing a foundation for siRNA-based treatments for a broad range of dermatological conditions.

Molecular mechanism of SmERF B3-4 in regulating lignin biosynthesis by modulating Sm4CL11 in Salix matsudana.

Integrated transcriptomic and metabolomic profiling and functional characterization of the MaXTH23 gene in boron stress adaptation in mulberry (Morus alba L.).

The membrane unsaturation in the liver is associated with abnormal biosynthesis and accumulation of cholesterol and triglycerides, which is a hallmark of metabolic dysfunction-associated steatotic liver disease (MASLD). The lysophosphatidylcholine acyltransferase 3 (LPCAT3) incorporates arachidonic acid (AA) into the membrane phospholipids and increases the degree of unsaturation. The metabolites of AA are involved in the lipogenesis under high nutrient conditions. However, the mechanistic insights by which LPCAT3 contribute to lipogenesis and MASLD remain unknown. This study found that LPACT3 is upregulated in the liver tissues of diet-induced MASLD and associated with a prominent increase in the arachidonic acid content in the liver, expression of lipogenic genes, and enlargement of liver cells filled with lipid droplets. Most importantly, the prostaglandin E2 (PGE2) was notably elevated in the plasma of the high-fat-fed mice. Gene silencing of LPCAT3 notably depleted the AA and PGE2 in the hepatocytes and attenuated the high-palmitic acid and glucose-induced accumulation of triglycerides and cholesterol. Exogenous addition of PGE2 markedly reversed the reduced triglyceride and cholesterol accumulation in the LPCAT3 silenced cells. These results indicate that the LPCAT3-arachidonic acid-PGE2 axis plays a crucial role in lipogenesis in response to excess nutrients in the liver. Most importantly, targeted pharmacologic therapy using GalNac-LPCAT3 siRNA specifically inhibits LPCAT3 expression in the liver and protects against high-fat-induced inflammation, lipogenesis and hepatic dysfunction without affecting hepatic VLDL secretion. This GalNAc-LPCAT3 siRNAbiomimeticcombined represented safe, effective, and versatile carriers for developing hepatocyte-specific gene therapeutics and preventing MASLD.

RNA interference (RNAi), a naturally occurring gene silencing mechanism found in almost all eukaryotic organisms, has proven to be an adaptable and powerful tool in therapeutics, bioengineering, and agriculture. Differential responses to RNAi, however, are a key limiting factor, in which cellular uptake of exogenous dsRNA in target organisms remains poorly understood. Here, to fill this knowledge gap, we integrated omics tools with phenotypic assays to characterize dsRNA uptake mechanisms across tissues in the migratory locust, Locusta migratoria (Orthoptera). Our findings clearly demonstrate that cellular uptake of dsRNA is tissue-dependent, involving multiple cell membrane receptors and pathways. In hemocytes, uptake is rapid and mediated by clathrin-mediated endocytosis and macropinocytosis. Epidermal cells utilize clathrin- and caveolin-mediated endocytosis, while midgut cells employ caveolin-mediated endocytosis and Sid-like channel transport. Comparatively, clathrin-mediated endocytosis appears to be the most conserved mechanism across insects, including the red flour beetle, Tribolium castaneum (Coleoptera), and the Asian corn borer, Ostrinia furnacalis (Lepidoptera). Taken together, dsRNA enters the cells of different tissue types through diverse pathways. This systematic and comprehensive study not only advances our understanding of the cellular uptake of extracellular dsRNA and the resultant differential sensitivity to RNAi in insects, but also facilitates the ongoing integration of this species-specific biotechnology into sustainable integrated pest management practices.

Reporter systems in actinomycetes: Versatile tools for natural product discovery and production.

Covering: 2000 to August 2025The search for new antimicrobial natural products from microorganisms has been limited by the transcriptional silencing of biosynthetic genes when microbes are cultivated outside their ecological environments. Nevertheless, applying knowledge of the ecological roles, for example, microbial defense against plant pathogens, can improve drug discovery efforts. Interactions between plants and their microbiota, during adaptation to pathogen stress, provide ecological cues that induce microenvironments suppressive to pathogens. This article highlights research linking pathogen-induced plant stress signals to the activation of microbial natural product biosynthesis, emphasizing the need for further studies on how plant metabolites can influence biosynthesis in plant-associated microbes.

Guanidinylated polymers enable safe and efficient dsRNA delivery in plant cells.

Dry powder inhalation of siRNA therapeutics: Emerging strategies for pulmonary gene silencing.

Cationic liposome-based silencing of thioredoxin reductase-1 for sensitization of MDA-MB 231 cells to gamma radiation.

Comparative genomics of the peach rot fungus Didymosphaeria rubi-ulmifolii reveal carbohydrate-active enzyme expansion and unique wood-decay strategies.

Small interfering RNA (siRNA) therapeutics are an emerging modality for treating genetic and metabolic diseases, with 8 approved drugs now in clinical use. Despite substantial advances in delivery technologies, including lipid nanoparticles and N-acetylgalactosamine conjugates, inefficient intracellular trafficking, particularly endosomal escape, remains a critical limitation. Here, we identify cellular cholesterol as a key regulator of siRNA intracellular trafficking, endosomal escape, and pharmacologic efficacy. Using a 2D hepatocyte cell culture model and cationic-lipid-mediated delivery, we show that pharmacologic cholesterol reduction via statin treatment significantly impairs siRNA-mediated gene silencing with minimal effects on cellular uptake, indicating a post-internalization trafficking defect. Cholesterol supplementation restores silencing, confirming its essential role in functional siRNA activity. Confocal imaging reveals increased siRNA entrapment in late endosomes following statin treatment, consistent with impaired endosomal escape. Notably, chloroquine, an endosomal escape enhancer, rescues gene silencing under cholesterol-reduced conditions. Mechanistically, we identify annexin A2 (ANXA2) as a critical mediator of this cholesterol-sensitive trafficking pathway, as ANXA2 knockdown abrogates the restorative effect of cholesterol supplementation. Together, these findings uncover a previously unrecognized cholesterol- and ANXA2-dependent mechanism regulating siRNA efficacy. While these mechanistic insights are specific to cationic-lipid-based delivery, they highlight intracellular cholesterol as an important determinant of siRNA endosomal escape. Future studies using microphysiological systems or in vivo models will be essential to validate and extend these findings beyond this 2D cell culture model. SIGNIFICANCE STATEMENT: This study uncovers cholesterol as an essential and previously unrecognized determinant of small interfering RNA therapeutic efficacy, acting through annexin A2 to enable endosomal escape, a critical bottleneck in RNA drug delivery. The findings position cholesterol modulation as a viable approach to improve the intracellular delivery and therapeutic effectiveness of RNA-based drugs.

KDM2A demethylase: A versatile epigenetic regulator in development, cancer, and therapeutic horizons.

The TET/5hmC mediated epigenetic landscape in glioma: From molecular mechanisms to therapeutic targeting and future perspectives.