Search Results (224)

Singlet oxygen (¹O₂), a reactive oxygen species, can oxidize lipids, proteins, and DNA at high concentrations, leading to cell death. Despite its extremely short half-life (10⁻⁵ s), ¹O₂ acts as a critical signaling molecule, triggering a retrograde pathway from chloroplasts to the nucleus to regulate nuclear gene expression. In this study, rice seeds were treated with 0, 5, 20 and 80 μM Rose Bengal (RB, a photosensitizer) under moderate light for 3 days to induce ¹O₂ generation. Treatment with 20 μM RB reduced stomatal density by approximately 25% in three-leaf-stage rice seedlings, while increasing the contents of pectin, hemicellulose, and cellulose in root cell walls by 30–40%. Under drought, salinity, or shading stress, 20 μM RB treatment significantly improved rice tolerance, as evidenced by higher relative water contents (49–58%) and chlorophyll contents (60–76%) and lower malondialdehyde (37–43%) and electrolyte leakage (29–37%) compared to the control. Moreover, RT-qPCR analysis revealed that the significant up-regulation of stomatal development genes (OsTMM and OsβCA1) and cell wall biosynthesis genes (OsF8H and OsLRX2) was associated with RB-induced ¹O₂ production. Thus, under controlled environmental conditions, ¹O₂ may regulate stomatal development and cell wall remodeling to enhance rice tolerance to multiple abiotic stresses. These results provide new perspectives for the improvement of rice stress tolerance. Full article

Leaves are essential for photosynthesis and transpiration, directly influencing plant growth and development. Leaf morphology, such as length, width, and area, affects photosynthetic efficiency and transpiration rates. In this study, we investigated the role of PtoWOX1 in leaf morphogenesis by generating both overexpression and CRISPR/Cas9 knockout lines in P. tomentosa. The results showed that PtoWOX1A and PtoWOX1B encode nuclear-localized transcription factors highly expressed in young leaves, particularly in palisade and epidermal cells. Knockout of PtoWOX1 resulted in reduced leaf width and area, enlarged upper epidermal cells, and lower stomatal density. Overexpression led to wrinkled leaf surfaces and reduced margin serration. Anatomical analysis revealed altered palisade cell arrangement and increased leaf thickness in knockout lines, accompanied by higher chlorophyll content and enhanced photosynthetic rates. Additionally, PtoWOX1A interacts with PtoYAB3B, suggesting a complex that regulates leaf margin development. These findings clarify the function of PtoWOX1 in regulating mid-lateral axis development and leaf margin morphology and provide new insights for the molecular breeding of poplar. Full article

Poly(ADP-ribosyl)ation is a crucial posttranslational modification that governs gene expression, chromatin remodeling, and cellular homeostasis. This dynamic process is mediated by the opposing activities of poly(ADP-ribose) polymerases (PARPs), which synthesize poly(ADP-ribose) (pADPr), and poly(ADP-ribose) glycohydrolase (PARG), which degrades it. While PARP function has been extensively studied, the structural and mechanistic basis of PARG-mediated pADPr degradation remain incompletely understood. To investigate the role of PARG in pADPr metabolism, we employed CRISPR/Cas9-based genome editing to generate a novel Parg^29b mutant mouse embryonic stem cell (ESC) line carrying a precise deletion within the PARG catalytic domain. This deletion completely abolished pADPr hydrolytic activity, resulting in massive nuclear pADPr accumulation, yet ESC viability, proliferation, and cell cycle progression remained unaffected. Using Drosophila melanogaster as a model system, we demonstrated that this mutation completely disrupted the pADPr pathway and halted developmental progression, highlighting the essential role of PARG and pADPr turnover in organismal development. Our results define a critical structural determinant of PARG catalytic function, underscore the distinct requirements for pADPr metabolism in cellular versus developmental contexts, and provide a genetically tractable model for studying the regulation of poly(ADP-ribose) dynamics and therapeutic responses to PARP inhibition in vivo. Full article

AT-hook motif nuclear-localized (AHL) genes play critical roles in chromatin remodeling and gene transcription regulation, profoundly influencing plant growth, development, and stress responses. While AHL genes have been extensively characterized in multiple plant species, their biological functions in pepper (Capsicum annuum L.) remain largely uncharacterized. In this study, we identified 45 CaAHL genes in the pepper genome through bioinformatics approaches. Comprehensive analyses were conducted to examine their chromosomal distribution, phylogenetic relationships, and the structural and functional features of their encoded proteins. Phylogenetic clustering classified the CaAHL proteins into six distinct subgroups. Transcriptome profiling revealed widespread expression of CaAHL genes across diverse tissues—including roots, stems, leaves, flowers, seeds, pericarp, placenta, and fruits—at various developmental stages. Quantitative real-time PCR further demonstrated that CaAHL1, CaAHL33, and CaAHL23 exhibited consistently high expression throughout flower bud development, whereas CaAHL36 showed preferential upregulation at early bud development stages. Expression profiling under hormone treatments and abiotic stresses indicated that CaAHL36 and CaAHL23 are auxin-inducible but are repressed by ABA, cold, heat, salt, and drought stress. Subcellular localization assays in Nicotiana benthamiana leaf epidermal cells showed that both CaAHL36 and CaAHL23 were predominantly localized in the nucleus, with faint expression also detected in the cytoplasm. Collectively, this study provides foundational insights into the CaAHL gene family, laying the groundwork for future functional investigations of these genes in pepper. Full article

Drought stress is a predominant abiotic constraint adversely affecting global rice (Oryza sativa) production and threatening food security. While the transcriptional and post-transcriptional regulation of drought-responsive pathways has been widely investigated, the emerging field of epitranscriptomics, particularly RNA chemical modifications such as N6-methyladenosine (m⁶A), adds a new dimension to gene regulation under stress. The most prevalent internal modification in eukaryotic messenger RNA influences RNA metabolism by interacting dynamically with enzymes that add, remove, or recognize the modification. Recent studies in rice reveal that m⁶A deposition is not static but dynamically regulated in response to water-deficit conditions, influencing transcript stability, splicing, nuclear export, and translation efficiency of key drought-responsive genes. This review critically synthesizes current findings on the distribution and functional implications of m⁶A and other epitranscriptomic marks (e.g., 5-methylcytosine [m⁵C], pseudouridine [Ψ]) in modulating rice responses to drought. We discuss the regulatory circuitry involving m⁶A effectors such as OsMTA, OsFIP37, and YTH domain proteins and their integration with known drought-signaling pathways including ABA and reactive oxygen species (ROS) cascades. We also highlight emerging high-resolution technologies such as m⁶A-seq, direct RNA sequencing, and nanopore-based detection that facilitate epitranscriptomic profiling in rice. Finally, we propose future directions for translating epitranscriptomic knowledge into crop improvement, including CRISPR/Cas-based modulation of RNA modification machinery to enhance drought tolerance. Full article

In addition to the male genome, the fertilizing spermatozoon delivers to the oocyte several factors whose deficiency can cause embryo dysfunction. Sperm oocyte-activating factor, identified as phoshoplipase C zeta (PLCζ), drives oocyte exit from meiotic arrest through a signaling pathway initiated by periodic rises of free cytosolic Ca²⁺ concentration (calcium oscillations). Sperm centrioles, together with oocyte proteins, form centrosomes that are responsible for aster formation, pronuclear migration, and DNA polarization before nuclear syngamy and subsequent mitotic divisions. Sperm DNA fragmentation can be at the origin of aneuploidies, while epigenetic issues, mainly abnormal methylation of DNA-associated histones, cause asynchronies of zygotic gene activation among embryonic cells. Sperm long and short non-coding RNAs are important epigenetic regulators affecting critical developmental processes. Dysfunction of sperm PLCζ, centrioles, DNA, and RNA mostly converge to aneuploidy, developmental arrest, implantation failure, miscarriage, abortion, or offspring disease. With the exception of DNA fragmentation, the other sperm issues are more difficult to diagnose. Specific tests, including heterologous human intracytoplasmic sperm injection (ICSI) into animal oocytes, genetic testing for mutations in PLCZ1 (the gene coding for PLCζ in humans) and associated genes, and next-generation sequencing of sperm transcriptome, are currently available. Oral antioxidant treatment and in vitro selection of healthy spermatozoa can be used in cases of sperm DNA fragmentation, while ICSI with assisted oocyte activation is useful to overcome oocyte-activation defects. No clinically confirmed therapy is yet available for sperm RNA issues. Full article

Brain ischemia-reperfusion (IR) injury is a critical pathological process that leads to extensive neuronal death, with hippocampal pyramidal cells, particularly those in the cornu Ammonis 1 (CA1) subfield, being highly vulnerable. Until now, human olfactory mitral cell resistance to IR injury has not been directly studied, but olfactory dysfunction in humans is frequently reported in systemic vascular conditions such as ischemic heart failure and may serve as an early clinical marker of neurological or cardiovascular disease. Mitral cells, the principal neurons of the olfactory bulb (OB), exhibit remarkable resistance to IR injury, suggesting the presence of unique molecular adaptations that support their survival under ischemic stress. Several factors may contribute to the resilience of mitral cells. They have a lower susceptibility to excitotoxicity, mitigating the harmful effects of excessive glutamate signaling. Additionally, they maintain efficient calcium homeostasis, preventing calcium overload—a major trigger for cell death in vulnerable neurons. Mitral cells may also express high baseline levels of antioxidant enzymes and their activities, counteracting oxidative stress. Their robust mitochondrial function enhances energy production and reduces susceptibility to metabolic failure. Furthermore, neuroprotective signaling pathways, including phosphatidylinositol-3-kinase (PI3K)/Akt, mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), and nuclear factor erythroid-2-related factor 2 (Nrf2)-mediated antioxidative responses, further bolster their resistance. In addition to these intrinsic mechanisms, the unique microvascular architecture and metabolic support within the olfactory bulb provide an extra layer of protection. By comparing mitral cells to ischemia-sensitive neurons, key vulnerabilities—such as oxidative stress, excitotoxicity, calcium dysregulation, and mitochondrial dysfunction—can be identified and potentially mitigated in other brain regions. Understanding these molecular determinants of neuronal survival may offer valuable insights for developing novel neuroprotective strategies to combat IR injury in highly vulnerable areas, such as the hippocampus and cortex. Full article

Background/Objectives: Abnormal bile acid (BA) pool may play an important role in inducing liver damage in sepsis. Farnesoid X receptor (FXR) is a main negative feedback regulator of BA metabolism. This study aims to explore the protective effect and mechanism of the FXR agonist obeticholic acid (OCA) on liver dysfunction when sepsis occurs. Methods: A rat model of sepsis was induced by cecal ligation and puncture (CLP) for 24 h. Systematic inflammation, tissue injury, hepatic FXR, and BA transporter expression were investigated in the CLP rats and sham-operated control rats with and without OCA pre-treatment (10 mg/kg, gavage) at 2 h before operation. Liquid chromatography–tandem mass spectrometry (LC-MS/MS) assay was performed to access BA composition in the rats’ serum and livers. The injury and inflammatory effects of the elevated unconjugated BAs found in the CLP rats was further verified in a hepatic cell line BRL-3A in vitro. Results: Hepatic FXR was repressed in CLP rats, whereas OCA upregulated liver FXR and hepatic BA transporter expression, reduced total serum BA concentration, ameliorated the elevation of serum levels of IL-1β and IL-6, and improved liver and ileal tissue injuries. OCA administration reduced the elevated unconjugated BAs in both serum and liver, and effectively inhibited increases in cholic acid (CA), deoxycholic acid (DCA), and 7-ketoDCA concentrations in CLP rat livers. These BA fractions promoted the release of aspartate aminotransferase (AST) from BRL-3A cells and increased IL-6, CXCL2, and monocyte chemoattractant protein-1 (MCP-1) expression in the cells, along with enhanced transcription factor nuclear factor-κB activation. Conclusions: Liver inflammation and dysfunction during sepsis is attributable to significant changes in bile acid composition in the blood and liver. FXR activation reduces systemic inflammation and liver dysfunction by regulating bile acid homeostasis, especially inflammatory unconjugated bile acid components. Full article

Background/Objectives: Breast cancer continues to be a major global health challenge, driving the urgent need for innovative therapeutic strategies. This study evaluates the anticancer and immunomodulatory potential of skimmianine in breast cancer through a comprehensive approach, integrating biochemical, histopathological, immunohistochemical, and bioinformatics analyses. Methods: Thirty-six female Wistar albino rats were divided into three groups: control, 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast cancer, and DMBA + skimmianine (n = 12/group). Breast cancer was induced with a single oral dose of 50 mg/kg DMBA in sesame oil. After 16 weeks, skimmianine (40 mg/kg) was administered intraperitoneally for four weeks. Serum CA15-3 levels were measured via enzyme-linked immunosorbent assay (ELISA). Histopathological assessment was performed using hematoxylin and eosin (H&E) staining, and proliferating cell nuclear antigen (PCNA) and tumor necrosis factor-alpha (TNF-α) were evaluated immunohistochemically. Pathway and hub gene analyses were performed using Cytoscape, functional annotation with Enrichr, and immune analyses via the Tumor and Immune System Interaction Database (TISIDB) and Sangerbox. Results: The tumor burden in the animals increased after DMBA induction compared to the control groups (0.00 ± 0.00% vs. 89.00 ± 6.60%, respectively, p < 0.001), while skimmianine treatment significantly reduced the tumor burden in the animals (49.00 ± 9.40%, vs. DMBA group, p = 0.191). Histopathological analysis showed DMBA-induced structural disorganization and malignant clustering, whereas skimmianine preserved ductal structures and mitigated the damage. Compared to the control group, DMBA administration markedly elevated serum CA15-3 levels (0.23 ± 0.06 ng/mL vs. 8.57 ± 1.01 ng/mL, respectively), along with PCNA (13.0 ± 3.0% vs. 25.0 ± 4.0%, respectively) and TNF-α (8.4 ± 1.7% vs. 34.0 ± 5.3%, respectively) expression, indicating active tumor progression. Skimmianine treatment significantly reduced CA15-3 (3.72 ± 0.58 ng/mL), PCNA (20.0 ± 4.1%), and TNF-α (25.0 ± 3.9%) levels (p < 0.001). In silico analyses indicated skimmianine’s effects on PCNA influence cell cycle pathways, while TNF-α suppression impacts toll-like receptor (TLR) signaling (adjusted p < 0.05). PCNA- and TNF-α-related anticancer effects were especially notable in basal molecular and C2 immune subtypes (p < 0.05). Related hub proteins may regulate immune dynamics by reducing immunosuppression and tumor-promoting inflammation (p < 0.05). Conclusions: Skimmianine shows promise as a breast cancer therapy by simultaneously targeting tumor growth and immune regulation, with PCNA and TNF-α identified as potential key players. Full article

Background: Polygalacturonase (PG) genes regulate plant organ abscission by degrading pectin in the cell wall. However, their association with pedicel abscission susceptibility in pepper remains poorly understood. Methods: 47 CaPG genes were identified were identified in the ‘Zunla1’ genome and characterized by structural, evolutionary, and comparative genomic analyses. Their expression profiles across various tissues and fruit development stages were examined using transcriptome data. Ethephon treatment and qRT-PCR were employed to assess gene responses during ethylene-induced pedicel abscission. Results: The 47 CaPG genes were distributed across 12 chromosomes, with CaPG1 to CaPG5 unanchored. Most proteins were hydrophilic, nuclear-localized, and had promoters enriched in light-responsive elements. Collinearity analysis revealed limited segmental duplication, and Ka/Ks values indicated strong purifying selection. Phylogenetic and collinearity analyses showed that CaPG genes are more closely related to those in tomato than in Arabidopsis or maize. Expression profiling revealed tissue- and stage-specific patterns, with 21 CaPG genes associated with pedicel abscission susceptibility. Ethephon treatment enhanced abscission and upregulated several CaPG genes. Conclusions: This study offers insights into the CaPG gene family’s structure, evolution, and function. Specific CaPG genes likely contribute to ethylene-mediated pedicel abscission, providing potential targets for improving fruit-retention traits in pepper. Full article

The mitochondrial phosphate carrier (mPiC), encoded by the nuclear gene SLC25A3, is synthesized with an N-terminus mitochondrial targeting sequence (MTS), enabling its import into the mitochondria. mPiC imports inorganic phosphate (P_i) into the mitochondrial matrix for ATP production and other matrix phosphorylation reactions, as well as regulates mitochondrial Ca²⁺ uptake and buffering of matrix Ca²⁺. PiC also imports copper (Cu), crucial to COX subunit holoenzyme assembly. Variants in SLC25A3 exist and lead to mPiC deficiency (MPCD), cause a rare autosomal recessive disease with no current cure; patients with MPCD usually die within the first year of life. We have developed a novel therapeutic approach using TAT-mPiC fusion protein for cellular delivery since the TAT peptide enables delivery of proteins across biological membranes. We designed, produced, and purified the TAT-mPiC fusion protein. The fusion protein is delivered into the mitochondria and localizes within the mIM, its natural cellular location, as a processed protein. Treatment of mPiC-knockdown cells with TAT-mPiC fusion protein increased cell growth and improved bioenergetic capabilities, as measured by oxygen consumption rate (OCR), ATP production, and reduction in lactate secretion. Most importantly, TAT-mPiC restored P_i and Cu delivery into the mitochondrial matrix. TAT-mPiC fusion protein also restored the mitochondrial activity of cells harboring various mitochondrial defects. This study presents the first successful delivery of a mitochondrial transmembrane carrier using the TAT-fusion system, offering a potential early treatment strategy for newborns with mPiC deficiency. Full article

Schizophrenia is a chronic and severe psychiatric disorder affecting approximately 1% of the global population, characterized by disrupted synaptic plasticity and brain connectivity. While substantial evidence supports its classification as a neurodevelopmental disorder, non-canonical neurodegenerative features have also been reported, with increasing attention given to astrocytic dysfunction. Overall, in this study, we explore the role of astrocytes as a structural and functional link between neurodevelopment and neurodegeneration in schizophrenia. Specifically, we examine how astrocytes contribute to forming an aberrant substrate during early neurodevelopment, potentially predisposing individuals to later neurodegeneration. Astrocytes regulate neurotransmitter homeostasis and synaptic plasticity, influencing early vulnerability and disease progression through their involvement in Ca²⁺ signaling and dopamine–glutamate interaction—key pathways implicated in schizophrenia pathophysiology. Astrocytes differentiate via nuclear factor I-A, Sox9, and Notch pathways, occurring within a neuronal environment that may already be compromised in the early stages due to the genetic factors associated with the ‘two-hits’ model of schizophrenia. As a result, astrocytes may contribute to the development of an altered neural matrix, disrupting neuronal signaling, exacerbating the dopamine–glutamate imbalance, and causing excessive synaptic pruning and demyelination. These processes may underlie both the core symptoms of schizophrenia and the increased susceptibility to cognitive decline—clinically resembling neurodegeneration but driven by a distinct, poorly understood molecular substrate. Finally, astrocytes are emerging as potential pharmacological targets for antipsychotics such as clozapine, which may modulate their function by regulating glutamate clearance, redox balance, and synaptic remodeling. Full article

The transcription factor erythroid 2-related factor 2 (Nrf2) is a central regulator of cellular defense mechanisms against oxidative stress and inflammation. Keap1 (Kelch-like ECH-associated protein 1) regulates Nrf2 activity by ubiquitination-mediated cytoplasmic retention, thereby suppressing its nuclear translocation and subsequent transcriptional activation of genes encoding phase II detoxifying enzymes. Using a structure-based virtual screening approach, we screened ~16,000 natural compounds to identify Keap1-Nrf2 PPI inhibitors. Nine compounds were identified based on their high binding affinities and favorable interactions with Keap1, primarily through non-covalent interactions. To validate the binding stability of these inhibitors, molecular dynamics (MD) simulations were performed, confirming the robustness of the Keap1–inhibitor complexes over time. Subsequent in vitro assays on human epithelial keratinocyte cells (HaCaT) revealed that six of these compounds notably upregulated Nrf2 mRNA expression, regis tering increases from 23% to 50% in comparison to the control. Notably, chebulinic acid emerged as the most potent compound, demonstrating the greatest elevation in Nrf2 expression. Penetration studies further showed that chebulinic acid, when encapsulated in silk fibroin, achieved a 0.14% penetration rate after 24 h though it could not penetrate into the stratum corneum alone. This result highlighted the potential of chebulinic acid in the use of anti-aging skincare formulations. Collectively, our findings affirmed that molecular docking is a reliable and effective approach for the identification of novel anti-aging agents targeting the Keap1-Nrf2 pathway. Full article

Poly(A) Binding Protein Nuclear 1 (PABPN1) is a nuclear poly(A)-binding protein that is highly conserved in eukaryotes. It plays multifaceted roles in RNA processing and metabolism, with its dysregulation closely linked to various diseases. PABPN1 contains an alanine-rich N-terminus, a central coiled-coil domain (CC), a conserved RNA recognition motif (RRM) and a C-terminal extension. PABPN1 influences mRNA splicing and stability through its RNA-binding capabilities, thereby modulating gene expression. While PABPN1 is known to interact with RNA, the molecular mechanism underlying this interaction with RNA awaits further investigation. Here, we designed and purified a PABPN1 fragment encompassing the RNA-binding domain (CCRRM fragment, amino acids 114–254). Using a combination of 3D modeling, small-angle X-ray scattering (SAXS) and selective 2′-hydroxyl acylation analyzed by primer extension (SHAPE) assay, our result indicated that CCRRM exhibits a high affinity for poly(A) RNA, a moderate affinity for GU-rich and CU-rich sequences, and negligible binding to AU-rich and CA-rich sequences. RNA binding induces conformation change in the CC. These results suggest that PABPN1 could potentially be involved in cytoplasmic polyadenylation and may influence the regulation of mRNA translation and degradation, although further investigation is required to confirm this role. Full article

This study designed three sgRNAs (sgRNA139, sgRNA128, and sgRNA109) targeting the prolactin gene receptor (PRLR) in fetal cattle, utilized Cas9 to cleave endogenous DNA, and screened stable cell lines for somatic cell nuclear transfer experiments to investigate the impact of different editing sites on embryonic development. The results showed that sgRNA139 had the highest cleavage efficiency (Fcut = 0.65, Indels = 42.19%), while sgRNA109 had the lowest (Fcut = 0.45, Indels = 35.31%). No significant differences were observed in cell growth status after electroporation (p > 0.05), and the transfection efficiency exceeded 90% after five days of culture. In the evaluation of key embryonic development indicators, sgRNA109 significantly reduced the cleavage rate and blastocyst rate (p < 0.01), whereas sgRNA139 showed no significant effect on the cleavage rate (p > 0.05), but its blastocyst rate was slightly lower than that of the control group (p > 0.05). This study demonstrates that highly specific sgRNAs and stable edited cell lines used as donor cells can significantly regulate the later stages of embryonic development. This study not only provides new experimental evidence for the functional study of the PRLR but also lays an important theoretical foundation for the innovation of molecular breeding technologies in dairy cattle. Full article