Search Results (353)

Acetylcholine (ACh) is the first identified neurotransmitter and an evolutionarily conserved signaling molecule. Although its role in classical synaptic transmission within the central and peripheral nervous systems has been extensively studied, growing evidence indicates that cholinergic signaling extends beyond neuronal synapses and operates in a broad range of non-neuronal cells. Thus, the cholinergic system represents a complex and widely distributed signaling network with both neuronal and non-neuronal components. Within the nervous system, cholinergic neurons display marked molecular heterogeneity, largely driven by the genomic organization and alternative splicing of the choline acetyltransferase (ChAT) gene. Distinct ChAT mRNA splice variants contribute to region- and cell-type specific cholinergic phenotypes in central and peripheral neurons, including the enteric nervous system, which exemplifies a highly autonomous peripheral cholinergic network. Beyond the nervous system, non-neuronal cholinergic signaling has been identified in epithelial, cardiac, immune, and other cell types, where ACh acts as an autocrine and paracrine regulator of key physiological processes. This review summarizes current knowledge on ACh biosynthesis, focusing on ChAT and its splice variants as molecular determinants of cholinergic diversity and function across neuronal and non-neuronal contexts. Full article

OAS1 (2′–5′-oligoadenylate synthetase 1) and OAS3 have been identified through a genome-wide association study as major loci associated with COVID-19. The rs10774671A>G variant affects alternative splicing and generates two distinct mRNA and protein isoforms. The A allele produces the shorter p42 isoform, which has been associated with increased susceptibility, greater disease severity, and higher mortality from COVID-19, whereas the G allele produces the longer p46 isoform, which has been associated with a protective effect. In addition, the functional variants OAS1 rs4767027C>T, OAS1 rs1131454A>G, and OAS3 rs10735079A>G have also been associated with susceptibility to and/or severity of COVID-19. Therefore, the aim of this study was to determine whether four variants in the OAS1 and OAS3 genes are associated with susceptibility to COVID-19 and with the clinical signs and symptoms of the disease. We included 305 patients with COVID-19 and 288 healthy controls. We genotyped the OAS1 rs10774671A>G, rs4767027C>T, rs1131454A>G, and OAS3 rs10735079A>G variants using TaqMan^® assays. The association between OAS1 and OAS3 variants and disease susceptibility or severity was assessed using binary logistic regression adjusted for age and sex. The Hardy–Weinberg equilibrium was evaluated using SNPStats, whereas haplotypes and linkage disequilibrium were analyzed with Haploview. Statistical power was calculated using Quanto. Logistic regression analysis adjusted for age and sex revealed an association between the OAS1 rs10774671A risk allele and susceptibility to COVID-19 (G vs. A: OR = 1.9, p = 0.007). In contrast, no associations with COVID-19 susceptibility were observed for the rs4767027C>T, rs1131454A>G, or rs10735079A>G variants. However, the rs1131454A>G and rs10735079A>G variants showed associations with sore throat. Overall, our findings suggest that OAS1 acts as a susceptibility factor for COVID-19 and the rs1131454A>G and rs10735079A>G SNVs are associated with sore throat in the Mexican population. Full article

Successful organ regeneration depends on coordinated cell-to-cell communication mediated by ligand–receptor interactions that regulate proliferation, differentiation, and axonal guidance. Sea cucumbers, particularly Holothuria glaberrima, exhibit remarkable regenerative capacity following evisceration, regenerating their complete intestinal system within weeks. To identify molecular signals orchestrating these events, we characterized five ligand–receptor groups of axonal guidance molecules (Netrin/UNC5-DSCAM, Ephrin/Eph receptors, Semaphorin/Plexin, RGMα/Neogenin, and SLIT/ROBO) using transcriptomic databases from regenerating intestines and the radial nerve cord. Comparative analyses confirmed these as highly conserved orthologs, retaining characteristic structural domains essential for guidance signaling. Multiple alternatively spliced isoforms were detected, with tissue-specific variants suggesting functional diversification. Differential gene expression analysis across intestinal regeneration stages (12 h to 21 days post-evisceration) revealed distinct temporal patterns: Netrin-1 showed significant upregulation at 7–14 days post-evisceration, coinciding with nerve fiber invasion into the intestinal anlage, while the Ephrin, Semaphorin, and SLIT–ROBO pathways exhibited late-stage expression associated with luminal tissue formation. Single-cell RNA sequencing from 9-dpe regenerating intestines localized Netrin to coelomic epithelial cells and UNC5B to differentiating epithelial cells, with CellChat analysis predicting strong epithelial-to-epithelial signaling. These findings strongly suggest that axonal guidance molecules play dual roles during intestinal regeneration: directing neural innervation in early-to-mid stages and orchestrating tissue boundary formation at later stages. Full article

Prostate cancer (PCa) progression is critically driven by androgen receptor (AR) signaling, which integrates hormonal cues with metabolic programs supporting tumor growth, survival, and therapy resistance. Emerging evidence suggests that intermittent fasting (IF) and related dietary interventions—such as time-restricted eating (TRE), alternate-day fasting (ADF), and fasting-mimicking diet (FMD)—modulate systemic metabolism, including reductions in insulin and insulin-like growth factor 1 (IGF-1), and induce intracellular nutrient stress that can influence AR activity, splice variant expression (e.g., AR-V7), and downstream metabolic pathways. This systematic literature review (Scopus, PubMed, Web of Science; publications up to December 2025; search terms: “prostate cancer,” “androgen receptor,” “AR splice variants,” “intermittent fasting,” “fasting mimicking diet”, “metabolism,” “therapy resistance”) summarizes preclinical and clinical studies addressing the impact of IF on AR signaling, lipogenesis, mitochondrial function, redox homeostasis, and therapy response. Preclinical studies indicate that IF can reduce AR expression, impair nuclear translocation, modulate AR splice variants such as AR-V7 via nutrient-sensitive splicing mechanisms, and enhance sensitivity to androgen deprivation therapy and AR-targeted agents. Mechanistically, IF-induced metabolic stress engages AMP-activated protein kinase (AMPK), mechanistic target of rapamycin (mTOR), and sirtuin pathways, alters lipid and mitochondrial metabolism, and transiently increases reactive oxygen species (ROS), creating vulnerabilities in prostate tumor cells. Translational evidence suggests potential benefits of integrating IF with standard therapy, but effects may depend on fasting regimen, caloric intake, macronutrient composition, and patient metabolic context, including risk of lean mass loss. This review highlights the metabolic crosstalk between IF and AR signaling and emphasizes the need for future clinical studies incorporating biomarker-guided approaches and body composition monitoring to fully exploit this intersection for improved therapeutic outcomes in prostate cancer. Full article

Alternative splicing (AS) and alternative polyadenylation (APA), as post-transcriptional regulatory mechanisms, are involved in various biological processes through the generation of transcript variants. However, genome-wide studies of AS and APA during spleen development are scarce. This study aimed to characterize transcript diversity and changes in transcript isoforms in the spleen at two developmental stages using full-length isoform sequencing integrated with short-read RNA sequencing. We revealed widespread transcript diversity and identified 17,294 unannotated transcripts, most of which originated from known genes in the current pig genome annotation. The top 500 genes with the highest isoform diversity were mainly associated with disease occurrence and immune function, as revealed by Kyoto Encyclopedia of Genes and Genomes enrichment analysis. We also observed changes in major transcript usage and polyadenylation site selection during spleen development. Our results indicated that genes regulated immunological development mainly by switching dominant transcript isoforms rather than altering overall expression levels. In addition, genes exhibited a tendency of age-dependent preference for distal polyadenylation sites. Furthermore, transcription factors important for spleen development were identified, and the regulatory axes MYBL2/WEE1 and E2F1/WEE1 were constructed for the first time using molecular biology techniques. These findings not only refined the current pig genome annotation, but also provided a foundation for exploring the molecular mechanisms responsible for spleen development. Full article

Background: The global transcriptome reprogramming in grapevines in response to powdery mildew remains poorly understood, despite its economic implications, especially the new cultivars. Methods: Thus, this study aimed to elucidate these changes through RNA sequencing in ‘Yeniang No. 2’ grapevine leaves infected with powdery mildew compared to healthy ones. Results: A total of six samples were subjected to transcriptome sequencing, resulting in 36.85 Gb of clean data. A minimum of 5.89 Gb of clean data was generated for each sample, with at least 92.24% of the clean data attaining a quality score of Q30. Clean reads from each sample were aligned to the designated reference genome. The mapping ratio varied between 88.77% and 89.66%. The high-quality sequencing data revealed 1219 differentially expressed genes (DEGs), of which the infection upregulated 790 and downregulated 429. Functional enrichment analyses revealed a significant activation of key defense-related pathways. These included plant–pathogen interaction, phenylpropanoid and flavonoid biosynthesis for creating antimicrobial compounds, glutathione metabolism for reducing oxidative stress, and oxidative phosphorylation for enhanced energy production. This indicates a coordinated, multi-faceted defense strategy. The study also uncovered a complex layer of post-transcriptional regulation, identifying 1883 novel genes and 22,210 alternative splicing events, primarily skipped exons and intron retention. Key hub proteins identified within interaction networks, along with these splicing changes, underscore a sophisticated defense involving transcriptional reprogramming and metabolic shifts. Conclusions: The genes and molecular markers discovered are valuable resources for marker-assisted breeding. Leveraging these findings, particularly hub genes and favorable splice variants, can accelerate the development of new grapevine cultivars with durable resistance to powdery mildew. Full article

Background: Prostate cancer remains a leading cause of male cancer-related mortality, largely driven by the dysregulated activation of the androgen receptor (AR) signaling pathway. The emergence of resistance, particularly in castration-resistant prostate cancer (CRPC), necessitates the discovery of innovative therapeutic approaches. This systematic review aims to consolidate contemporary evidence regarding natural products as bioactive alternatives capable of targeting the AR signaling axis. Methods: Adhering to PRISMA guidelines, a systematic search was conducted across PubMed, Scopus, and ScienceDirect databases. The review identified and qualitatively analyzed 15 original research studies that investigated the efficacy and mechanisms of various natural compounds in modulating AR signaling. Results: The analysis reveals that natural products deactivate the AR signaling axis through diverse mechanisms. Neoisoliquiritin and α-terthienyl were found to suppress AR expression, activity, and nuclear translocation. Notably, α-mangostin facilitates the degradation of the AR-V7 splice variant, a key driver of treatment resistance. Manzamine A inhibits AR biosynthesis by targeting the transcription factor E2F8. Furthermore, alternative pathways are modulated through 5-α-reductase inhibition (Annona muricata compounds) and the activation of the non-classical membrane receptor ZIP9 by (-)-epicatechin to induce apoptosis. Conclusions: The emergence of resistance, particularly in castration-resistant prostate cancer (CRPC), necessitates the exploration of innovative therapeutic approaches. This systematic review consolidates contemporary evidence regarding natural products as potential bioactive alternatives for modulating the androgen receptor (AR) signaling axis. Rather than providing a definitive clinical roadmap, this work establishes a preclinical framework for identifying substances that may deactivate the receptor, break down its resistant forms, or prevent nuclear translocation. Full article

Background: This study aimed to develop a superior aptamer-based therapeutic for targeted glioblastoma intervention by conducting a comparative analysis of two DNA aptamers: the original U2 sequence, selected against glioblastoma cells exhibiting high EGFRvIII expression, and its modified, shortened, and stabilized variant, Gol1. Methods: The effects of the investigated aptamers on primary human glioblastoma cells with graded receptor expression levels and on a rat 101/8 glioblastoma tissue model were rigorously studied. Results: The results demonstrated the significant superiority of the stabilized Gol1 aptamer, which exhibited exceptional binding affinity for the EGFRvIII receptor. Pronounced antiproliferative and antimigratory effects against EGFRvIII-positive human tumor cells, ultimately inducing complete cell death. Transcriptomic analysis revealed a sophisticated dual mechanism of action for Gol1: the specific activation of neuronal differentiation genes concurrent with the suppression of key alternative splicing factors. Crucially, in vivo confirmation showed highly selective accumulation of the FAM-labeled Gol1 aptamer exclusively within tumor tissue, with a maximum concentration gradient observed in the invasive border zone and a complete absence of accumulation in intact brain parenchyma. Conclusions: These comprehensive findings confirm that the Gol1 aptamer constitutes a highly promising and versatile platform for developing novel targeted theranostic strategies against glioblastoma, offering a precise approach for both diagnostic imaging and therapeutic intervention. Full article

The human ALKBH gene family comprises nine Fe²⁺/α-ketoglutarate-dependent dioxygenases that catalyze the oxidative demethylation of DNA, RNA, and proteins, thereby influencing key cellular processes. Consequently, dysregulation of these enzymes has been implicated in various human diseases, particularly cancer. Although the transcriptomic profiles of certain members (e.g., ALKBH8, FTO) have been characterized, a comprehensive analysis of the entire ALKBH family remains unclear. In the present study, we investigated the alternative splice variants of the ALKBH genes through direct RNA sequencing across cancerous and non-cancerous cell lines. Novel splicing events were validated by NGS, while RT-qPCR was employed to assess transcript abundance and expression patterns. Additionally, in silico analysis was performed to predict the coding potential of the detected transcripts. Results: Bioinformatics analysis revealed previously uncharacterized alternative transcripts for the human ALKBH gene family members. Expression profiling demonstrated distinct expression patterns between cancerous and non-malignant cells, suggesting a potential role of these demethylases in tumor biology. The investigation of their coding capacity revealed that most of the newly detected transcripts were predicted to encode protein isoforms, highlighting the structural and predicted coding potential of the ALKBH family. Conclusions: Our findings provide the first comprehensive overview of the transcriptional diversity within the human ALKBH gene family. These results enhance our understanding of the demethylation mechanisms and their dysregulation in cancer. Full article

Anthocyanins, as natural pigments with high nutritional value, have been extensively studied in terms of their biosynthetic pathways. However, the specific impact of alternative splicing (AS) on anthocyanin biosynthesis in potatoes and its potential regulatory mechanisms remain unclear. This study analyzed full-length transcriptome (SMRT) and Illumina RNA-seq datasets from three developmental stages of multiple potato (Solanum tuberosum L.) cultivars. After RNA-seq correction, numerous AS events were identified in both white and colored samples. To dissect the regulatory role of AS in anthocyanin biosynthesis, we further analyzed the AS patterns of anthocyanin biosynthesis-related structural genes and transcription factors (TFs). Through this targeted analysis, we found that a subset of these structural genes and TFs exhibited AS, generating functionally diverse transcript variants. Among these, the candidate gene StB3-like (Soltu.DM.04G010530), a B3 family TF associated with anthocyanin synthesis, was selected for preliminary functional validation. This gene produced three alternatively spliced transcripts (StB3-like-1, -2, -3). Transient co-expression with StAN1 (Soltu.DM.10G020850) in tobacco showed that StB3-like-2 and StB3-like-3 significantly increased anthocyanin accumulation, whereas StB3-like-1 had no effect. These results confirm that different transcripts produced by the alternative splicing of the same gene differentially regulate anthocyanin accumulation in a StAN1-dependent manner, laying the groundwork for further investigation into the role of alternative splicing in potato anthocyanin accumulation. Full article

Phytochelatin synthases (PCSs) are pivotal enzymes in heavy metal detoxification, yet also implicated in sulfur homeostasis and redox regulation. In this study, we report the molecular and functional characterization of the PCS gene from the green alga Scenedesmus acutus (SaPCS), comparing wild-type and chromium-tolerant strains of this microalga. RT-qPCR, immunoblotting and mass spectrometry analyses revealed that SaPCS expression and protein abundance are primarily regulated by sulfur availability rather than by chromium stress. Two protein isoforms (~70 kDa full-length and ~34 kDa truncated) were detected, both more abundant in the chromium-tolerant strain than the wild-type and responsive to sulfur availability. Furthermore, three alternatively spliced transcript variants (SaPCSa, SaPCSb, SaPCSc) lacking the C-terminal domain coding region but retaining a functional or partially disrupted N-terminal catalytic domain were identified, contributing to the post-transcriptional diversification of PCSs. Mass spectrometry analyses showed negligible phytochelatin production in response to chromium treatment, indicating that detoxification of this metal in S. acutus relies mainly on glutathione (GSH) conjugation and the ascorbate–GSH antioxidant cycle. Overall, these results suggest that SaPCS may promote chromium tolerance by modulating sulfur and redox metabolism rather than by driving phytochelatin accumulation, highlighting the remarkable functional plasticity of PCSs in algal stress responses. Full article

Background/Objectives: Approximately 10–15% of cancers rely on Alternate Lengthening of Telomeres (ALT), which is a telomerase-independent, BIR (Break-Induced Replication)-based pathway for maintaining long-term replicative potential. Methods: As ALT is over-represented in mesenchymal-type tumors, we investigated, via RNA-seq, the extent to which the EMT-promoting factor ZEB1 regulates this pathway. Results: The ALT-associated genes targeted by ZEB1, including PML, RMI2, POLD4, RPA3 (induced), SLX4, and WRN (repressed), in the aggregate, suggest that it regulates ALT at multiple steps in that pathway. ZEB1-deficient cells showed a significant reduction in telomere length as well as in two hallmarks of ALT, C-circle levels and the size and number of ALT-associated PML Bodies (APBs), which are the telomere-aggregating compartments in which BIR occurs. As one of the most highly regulated genetic targets of ZEB1 was the pro-epithelial alternative splicing factor ESRP1, we investigated whether the repression of this factor was required to generate the PML splice variant isoform IV, which is the major structural component of APBs. We found an inverse relationship between the expression of this protein and levels of PML isoform IV mRNA. Conclusions: These findings suggest a novel role for ZEB1 in promoting ALT both transcriptionally and post-transcriptionally at multiple levels. Full article

Tau proteins are microtubule-associated proteins that regulate axonal structure, dynamics, and transport, and their dysregulation underlies several neurodegenerative diseases. The MAPT gene produces multiple tau isoforms through alternative splicing, including the high-molecular-weight isoform known as Big tau, which contains an insert of the large 4a exon of approximately 250 amino acids. Big tau is predominantly expressed in neurons of the peripheral nervous system (PNS), cranial motor nuclei, and select neurons of the central nervous system (CNS) such as the cerebellum and brainstem. Developmental expression studies indicate a switch from low-molecular-weight isoforms of tau to Big tau during axonal maturation, suggesting that Big tau optimizes cytoskeletal dynamics to accommodate long axonal projections. Comparative sequence and biophysical analyses show that the exon-4a insert is highly acidic, intrinsically disordered, and evolutionarily conserved in its length but not its primary sequence, implying a structural role. Emerging modeling and in vitro assays suggest that the extended projection domain provided by the exon-4a insert spatially and electrostatically shields the aggregation-prone PHF6 and PHF6* motifs in tau’s microtubule-binding domain, thereby reducing β-sheet driven aggregation. This mechanism may explain why tauopathies that involve aggregation of tau have little effect on the PNS and specific regions of the CNS such as the cerebellum, where Big tau predominates. Transcriptomic and proteomic data further suggest that alternative Big tau variants, including 4a-L, are expressed in certain cancerous tissues, indicating broader roles in cytoskeletal remodeling beyond neurons. Despite its putative anti-aggregation properties, the physiological regulation, interaction partners, and in vivo mechanisms of Big tau remain poorly defined. This review summarizes what is known about Big tau and what is missing toward a better understanding of how expansion via inclusion of exon 4a modifies tau’s structural and functional properties. Our purpose is to inspire future studies that could lead to novel therapeutic strategies to mitigate tau aggregation in neurodegenerative diseases. Full article

Sexual size dimorphism (SSD) refers to the phenomenon where males and females of the same species exhibit differences in overall or partial body size, and it is widespread among mammals, birds, reptiles, and fish. Notably, this dimorphism is significantly influenced by the sexually dimorphic secretion of growth hormone (gh), a key pituitary-derived growth regulator. Commonly, the secretion of gh is positively regulated by glucagon family members such as growth hormone-releasing hormone (ghrh) and adenylate cyclase-activating polypeptide 1 (adcyap1). To explore the stimulators for pituitary hormones (especially gh) in the teleost, we performed genome-wide identification and functional characterization of the glucagon family on Chinese tongue sole (Cynoglossus semilaevis) that exhibits typical female-biased sexual size dimorphism. Four members of adcyap1/vasoactive intestinal polypeptide(vip)/ghrh family and ten members of their receptor family were identified. Expression pattern analysis revealed high expression of adenylate cyclase-activating polypeptide 1b (adcyap1b) and its receptors in the brain. Moreover, two alternative splice variants for the adcyap1b gene were discovered, resulting from the skipping of exon 4. Following the acquisition of the two eukaryotic recombinant protein splice variants (ADCYAP1b_tv1 and ADCYAP_tv2) from HEK 293T cells, incubation experiments were conducted using C. semilaevis pituitary cell line. The results demonstrated that both variants promoted the expression of gh, pro-opiomelanocortin (pomc), and corticoliberin (crh), but ADCYAP1b_tv1 had a significantly stronger effect and uniquely stimulated prolactin (prl) and somatolactin (sl). This study demonstrates a functional divergence between the two ADCYAP1b splice variants in teleosts, with ADCYAP1b_tv1 acting as a more potent and versatile pituitary hormone stimulator. Further research on their receptor-binding affinity and downstream signaling pathways would be valuable for exploring the mechanism underlying sexual size dimorphism. Full article

Alternative splicing (AS) is a crucial post-transcriptional regulatory mechanism in eukaryotes. Plants can cope with complex environmental changes through AS. In this paper, we found that AS plays an important role in plant responses to biotic and abiotic stresses. First, we note that under biotic stress (e.g., disease, insects), AS regulates the expression of immune-related genes and produces splice variants with different functions to regulate plant disease resistance. Second, under abiotic stress (e.g., drought, cold, heat, salt), plants generate functional splice variants via different AS events and change the original function of the gene. At the same time, we also found that splicing factors and regulatory elements, such as serine/arginine-rich proteins associated with AS, are also involved in the regulation of the expression of related resistance genes to improve plant stress resistance. Therefore, this review summarizes the recent progress on the main types of AS events, the functions of related splicing factors, and the action routes and regulatory mechanisms of splice variants. We hope to provide a reference for further understanding of the stress response mechanism of plant AS and provide a theoretical basis for the breeding of resistant varieties. Full article