Search Results (229)

The aberrant activation of glycolysis plays a pivotal role in the progression of liver diseases. Pyruvate kinase M2 (PKM2), one of the rate-limiting enzymes of glycolysis, not only regulates cellular metabolism but also translocates to the nucleus in its dimeric form, acting as a co-factor to modulate gene transcription. To further explore the regulatory mechanisms of PKM2, this review outlines the effects of post-translational modifications on PKM2’s structure, activity, and localization, and discusses the integrative role of PKM2 in epigenetics and metabolism, providing a foundation for the development of PKM2 regulators. Due to PKM2’s distinct biochemical properties, targeting PKM2 with specific regulators may offer a promising therapeutic strategy for the treatment of liver diseases. Full article

Hydrogen sulfide (H₂S), nitric oxide (NO), and carbon monoxide (CO) are now recognized as key gasotranmitters that regulate vascular function, contributing to vasodilation, angiogenesis, inflammation control, and oxidative balance. Initially regarded as toxic gases, they are produced on demand by specific enzymes, including cystathionine γ-lyase (CSE), endothelial nitric oxide synthase (eNOS), and heme oxygenase-1 (HO-1). Their activity is tightly controlled by redox-sensitive pathways. Reactive oxygen species (ROS), particularly superoxide and hydrogen peroxide, modulate gasotransmitter biosynthesis at the transcriptional and post-translational levels. Moreover, ROS affect gasotransmitter availability through oxidative modifications, including thiol persulfidation, nitrosative signaling, and carbonylation. This redox regulation ensures a tightly coordinated response to environmental and metabolic cues within the vascular system. This review synthesizes the current understanding of redox–gasotransmitter interactions, highlighting how ROS modulate the vascular roles of H₂S, NO, and CO. Understanding these interactions provides critical insights into the pathogenesis of cardiovascular diseases and offers potential redox-targeted therapies. Full article

The liver orchestrates metabolic homeostasis through dynamic post-translational modifications. β-hydroxybutyrylation (Kbhb), a ketone body-driven modification, regulates epigenetics and metabolism in humans and mice but remains unexplored in livestock. Here, we characterize the porcine hepatic β-hydroxybutyrylome using high-resolution mass spectrometry, identifying 4982 Kbhb sites on 2122 proteins—the largest dataset to date. β-hydroxybutyrylation predominantly targets non-histone proteins (99.68%), with enrichment in fatty acid β-oxidation, TCA cycle, and oxidative phosphorylation pathways. Subcellular localization revealed cytoplasmic (38.1%), mitochondrial (18.1%), and nuclear (15.3%) dominance, reflecting BHB-CoA synthesis sites. Motif analysis identified conserved leucine, phenylalanine, and valine residues at modified lysines, suggesting enzyme-substrate specificity. β-hydroxybutyrate treatment elevated global Kbhb levels, increasing TCA intermediates (e.g., α-ketoglutarate, +9.56-fold) while reducing acetyl-CoA, indicating enhanced mitochondrial flux. Cross-species comparisons showed tissue-specific Kbhb distribution (nuclear in human cells vs. mitochondrial in mice), highlighting metabolic adaptations. This study establishes pigs as a model for Kbhb research, linking it to energy regulation and providing insights into metabolic reprogramming. Full article

The complex pathological mechanisms of atherosclerosis (AS) involve lipid metabolism disorders, inflammatory responses, and plaque instability, resulting in significant challenges to effective clinical management. Current therapeutic approaches, such as statins and stent implantation, suffer from issues including single-target action, notable side effects, and the risk of restenosis. Nanoparticle-based drug delivery systems have demonstrated considerable promise by enabling the codelivery of multiple agents directly to atherosclerotic lesions, thereby improving therapeutic efficacy and minimizing systemic toxicity. Among various nanomaterials, organic nanoparticles have recently emerged as a research hotspot in the field of AS treatment due to their excellent biocompatibility, degradability, and potential for targeted modification. This review systematically summarizes the recent advances and emerging trends in the application of organic nanoparticles for AS treatment, employing bibliometric analysis to delineate research frontiers. We employed bibliometric tools to analyze 1999 articles on organic nanocarriers for AS therapy indexed in the Web of Science Core Collection. The analysis included co-occurrence and clustering techniques to explore influential keywords and key contributors. Temporal analysis was applied to identify emerging research hotspots and track the evolution of this field. The literature reveals three major current focal areas: (1) the development of engineered biomimetic organic nanoparticles; (2) the design of multifunctional polymer-based organic nanocarriers; and (3) the innovation of organic-coated stents. This article not only provides a comprehensive overview of cutting-edge organic nanotechnologies for AS therapy, but also critically discusses the challenges in clinical translation, offering insights into future directions for the development of safe, effective, and personalized nanomedicine strategies against AS. Full article

Nanovaccines have emerged as a transformative platform in immunotherapy, distinguished by their capabilities in targeted antigen delivery, enhanced immunogenicity, and multifunctional integration. By leveraging nanocarriers, these vaccines achieve precise antigen transport, improve immune activation efficiency, and enable synergistic functions such as antigen protection and adjuvant co-delivery. This review comprehensively explores the foundational design principles of nanovaccines, delves into the diversity of nanovaccine design strategies—including the selection of primary carrier materials, functionalization modification, synergistic delivery of immune adjuvants, and self-assembled nano-delivery systems—and highlights their applications in cancer immunotherapy, infectious disease and autoimmune diseases. Furthermore, it critically examines existing technical challenges and translational barriers, providing an integrative reference to guide future research and development in this dynamic field. Full article

Hepatitis B virus (HBV) remains a major global health challenge, with over 296 million people chronically infected worldwide. Despite the availability of antiviral therapies, a functional cure is rarely achieved, highlighting the need for novel therapeutic strategies. RNA 5-methylcytosine (m⁵C) is a pivotal epitranscriptomic mark implicated in RNA stability, transport, and translation. Emerging evidence shows that m⁵C is conserved within HBV RNA and plays critical roles in the viral life cycle. This review provides a comprehensive overview of the molecular mechanisms governing m⁵C deposition and recognition, summarizes recent advances in m⁵C biology, and highlights the emerging role of epitranscriptomic m⁵C regulation in HBV infection. We discuss the identification of HBV-specific m⁵C sites, the functions of key regulatory enzymes, and their interplay in viral RNA stabilization and evasion of innate immune responses. Interplay between m⁵C and other RNA modifications—particularly N6-methyladenosine (m⁶A)—is examined alongside virus-specific m⁵C regulation in EV71, HIV, HCV, EBV, and SARS-CoV-2. Potential links between m⁵C dysregulation and HBV-induced hepatocarcinogenesis are outlined, and emerging therapeutic strategies targeting the m⁵C machinery are highlighted. Together, these insights position the epitranscriptomic landscape as a promising avenue for innovative antiviral strategies. Full article

Multidrug resistance (MDR) remains a formidable barrier to successful cancer treatment, driven by mechanisms such as efflux pump overexpression, enhanced DNA repair, evasion of apoptosis and the protective characteristics of the tumour microenvironment. Nanoparticle-based delivery systems have emerged as promising platforms capable of addressing these challenges by enhancing intracellular drug accumulation, enabling targeted delivery and facilitating stimuli-responsive and controlled release. This review provides a comprehensive overview of the molecular and cellular mechanisms underlying MDR and critically examines recent advances in nanoparticle strategies developed to overcome it. Various nanoparticle designs are analysed in terms of their structural and functional features, including surface modifications, active targeting ligands and responsiveness to tumour-specific cues. Particular emphasis is placed on the co-delivery of chemotherapeutic agents with gene regulators, such as siRNA, and the use of nanoparticles to deliver CRISPR/Cas9 gene editing tools as a means of re-sensitising resistant cancer cells. While significant progress has been made in preclinical settings, challenges such as tumour heterogeneity, limited clinical translation and immune clearance remain. Future directions include the integration of precision nanomedicine, scalable manufacturing and non-viral genome editing platforms. Collectively, nanoparticle-based drug delivery systems offer a multifaceted approach to combat MDR and hold great promise for improving therapeutic outcomes in resistant cancers. Full article

Colchicine is a potent alkaloid with well-established anti-inflammatory properties. It shows significant promise in treating classic immune-mediated inflammatory diseases, as well as associated cardiovascular diseases, including atherosclerosis. However, its clinical use is limited by a narrow therapeutic window, dose-limiting systemic toxicity, variable bioavailability, and clinically significant drug–drug interactions, partly mediated by modulation of P-glycoprotein and cytochrome P450 3A4 metabolism. This review explores advanced delivery strategies designed to overcome these limitations. We critically evaluate lipid-based systems, such as solid lipid nanoparticles, liposomes, transferosomes, ethosomes, and cubosomes; polymer-based nanoparticles; microneedles; and implants, including drug-eluting stents. These systems ensure targeted delivery, improve pharmacokinetics, and reduce toxicity. Additionally, we discuss chemical derivatization approaches, such as prodrugs, codrugs, and strategic ring modifications (A-, B-, and C-rings), aimed at optimizing both the efficacy and safety profile of colchicine. Combinatorial nanoformulations that enable the co-delivery of colchicine with synergistic agents, such as glucocorticoids and statins, as well as theranostic platforms that integrate therapeutic and diagnostic functions, are also considered. These innovative delivery systems and derivatives have the potential to transform colchicine therapy by broadening its clinical applications while minimizing adverse effects. Future challenges include scalable manufacturing, long-term safety validation, and the translation of research into clinical practice. Full article

tRNA modifications are crucial for efficient protein synthesis, impacting codon recognition, tRNA stability, and translation rates. RNA viruses hijack the host’s translational machinery, including the pool of modified tRNA, to translate their own genomes. However, the mismatch between viral and host codon usage can lead to a limited availability of specific tRNA leading to ribosome stalling, posing a significant challenge for efficient protein translation. While some viruses address this challenge through codon optimization, we show here that SARS-CoV-2 (Coronavirus) and the Zika virus (ZIKV; Flavivirus) adopt a different approach, manipulating the host tRNA epitranscriptome. Analysis of codon bias indices confirmed a substantial divergence between viral and host codon usage, revealing a strong preference in viral genes for codons decoded by tRNAs requiring U34 wobble modification. Monitoring tRNA modification dynamics in infected cells showed that both SARS-CoV2 and ZIKV enhance U34 tRNA modifications during infection. Strikingly, impairing U34 tRNAs profoundly impacted viral replication, underscoring the strict reliance of SARS-CoV-2 and ZIKV on manipulating the host tRNA epitranscriptome to support the efficient translation of their genome. Full article

Intrinsically disordered regions (IDRs), defined as protein segments lacking stable tertiary structures, are ubiquitously present in the human proteome and enriched with disease-associated mutations. IDRs harbor molecular recognition features (MoRFs) and post-translational modification sites (e.g., phosphorylation), enabling dynamic intermolecular interactions through conformational plasticity. Furthermore, IDRs drive liquid–liquid phase separation (LLPS) of biomacromolecules via multivalent interactions such as electrostatic attraction and pi–pi interactions, generating biomolecular condensates that are essential throughout the cellular lifecycle. These condensates separate intracellular space, forming a physical barrier to avoid interference between other molecules, thereby improving reaction specificity and efficiency. As a dynamically equilibrated process, LLPS formation and maintenance are regulated by multiple factors, endowing the condensates with rapid responsiveness to environmental cues and functional versatility in modulating diverse signaling cascades. Consequently, disruption of LLPS homeostasis can derail its associated biological processes, ultimately contributing to disease pathogenesis. Moreover, precisely because liquid–liquid phase separation (LLPS) is co-regulated by multiple factors, it may provide novel insights into the pathogenic mechanisms of disorders such as autism spectrum disorder (ASD), which result from the cumulative effects of multiple etiological factors. Full article

Background/Objectives: Neurodevelopmental disorders (NDDs) represent a clinically diverse group of conditions that affect brain development, often leading to varying degrees of functional impairment. Many NDDs, particularly syndromic forms, are caused by genetic mutations affecting critical cellular pathways. Ribosomopathies, a subgroup of NDDs, are linked to defects in ribosomal function, including those involving the synthesis of diphthamide, a post-translational modification of translation elongation factor 2 (eEF2). Loss-of-function (LoF) mutations in genes involved in diphthamide biosynthesis, such as DPH1, DPH2, and DPH5, result in developmental delay (DD), intellectual disability (ID), and multisystemic abnormalities. DPH5-related diphthamide deficiency syndrome has recently been reported as an ultrarare disorder linked to LoF mutations in DPH5, encoding a methyltransferase required for diphthamide synthesis. Methods: Clinical, neurological, and dysmorphological evaluations were performed by a multidisciplinary team. Brain MRI was acquired on a 3T scanner. Craniofacial abnormalities were assessed using the GestaltMatcher phenotyping tool. Whole exome sequencing (WES) was conducted on leukocyte-derived DNA with a trio-based approach. Bioinformatic analyses included variant annotation, filtering, and pathogenicity prediction using established databases and tools. Results: The affected subject carried a previously reported missense change, p.His260Arg, suggesting the occurrence of genotype–phenotype correlations and a hypomorphic behavior of the variant, likely explaining the overall milder phenotype compared to the previously reported patients with DPH5-related diphthamide deficiency syndrome. Conclusions: Overall, the co-occurrence of short stature, relative macrocephaly, congenital heart defects, variable DD/ID, minor skeletal and ectodermal features, and consistent craniofacial features suggests a differential diagnosis with Noonan syndrome and related phenotypes. Full article

Background: Organic anion transporter 3 (OAT3) in the kidney proximal tubule cells plays a critical role in renal clearance of numerous endogenous metabolites and exogenous drugs and toxins. In this study, we discovered that epidermal growth factor (EGF) regulates the expression and activity of OAT3 through palmitoylation, a novel mechanism that has never been described in the OAT field. Methods/Results: Our results showed that treatment of OAT3-expressing cells with EGF led to a ~40% increase in OAT3 expression and OAT3-mediated transport of estrone sulfate, a prototypical substrate for OAT3. EGF-stimulated OAT3 transport activity was abrogated by H-89, a protein kinase A (PKA) inhibitor, indicating that an EGF-PKA signaling pathway is involved in the regulation of OAT3. We also showed that treatment of OAT3-expressing cells with EGF resulted in an enhancement of OAT3 palmitoylation, a novel type of post-translational modification for OATs, and such an enhancement was blocked by H-89, suggesting that the EGF-PKA signaling pathway participated in the modulation of OAT3 palmitoylation. Palmitoylation was catalyzed by a group of palmitoyltransfereases, and we showed that OAT3 palmitoylation and expression were inhibited by 2-BP, a general inhibitor for palmitoyltransfereases. We also explored the relationship among EGF/PKA signaling, OAT palmitoylation, and OAT transport activity. We treated OAT3-expressing cells with EGF or Bt2-cAMP, a PKA activator, in the presence and absence of 2-BP, followed by the measurement of OAT3-mediated transport of estrone sulfate. We showed that both EGF- and Bt2-cAMP-stimulated OAT3 transport activity were abolished by 2-BP, suggesting that palmitoylation mediates the regulation of EGF/PKA on OAT3. Finally, we showed that osimertinib, an anti-cancer drug/EGFR inhibitor, blocked EGF-stimulated OAT3 transport activity. Conclusions: In summary, we provided the first evidence that palmitoylation transduces the EGF/PKA signaling pathway to the modulation of OAT3 expression and function. Our study also provided an important implication that during comorbidity therapies, EGFR inhibitor drugs could potentially decrease the transport activity of renal OAT3, which would subsequently alter the therapeutic efficacy and toxicity of many co-medications that are OAT3 substrates. Full article

Male infertility contributes to approximately half of all infertility cases, with most cases associated with oxidative stress. Spermatozoa depend on finely tuned redox signaling for critical processes such as capacitation, motility, and fertilization competence; however, their unique structural and metabolic features render them particularly vulnerable to oxidative damage. Reversible oxidative modifications regulate enzymatic activity, signaling cascades, and structural stability, supporting normal sperm function, whereas irreversible oxidative damage impairs motility, acrosome reaction, and DNA integrity, contributing to male infertility. The intricate balance between physiological redox signaling and pathological oxidative stress demonstrates the potential of redox modifications as biomarkers for infertility diagnosis and as targets for antioxidant-based therapeutic interventions. This review explores the role of redox-induced protein modifications in sperm function, focusing on thiol oxidation, S-nitrosylation, sulfhydration, glutathionylation, CoAlation, and protein carbonylation. By uncovering the mechanisms of these redox modifications, we provide a framework for their modulation in the development of targeted redox interventions to improve male fertility. Full article

Negative-sense RNA viruses comprise a wide array of viral families, such as Orthomyxoviridae, Paramyxoviridae, Rhabdoviridae, and Morbillivirus, all of which are adept at inciting significant epidemic outbreaks. Throughout their replication cycle, these viruses engage in a variety of RNA modifications, during both the co-transcriptional and post-transcriptional phases, which are mediated by specific enzymatic activities. These chemical alterations play a critical role in shaping viral fitness, particularly in terms of evading innate immune responses. Key chemical modifications, such as adenosine methylation, 2′-O methylation of nucleosides, and adenosine-to-inosine editing, play critical roles in determining the stability, translational efficiency, and immune recognition of viral RNA. These modifications can reduce the activation of immune sensors, thereby suppressing interferon production and broader antiviral responses. In contrast, certain modifications may enhance immune recognition, which opens avenues for novel vaccine and antiviral strategy development. A comprehensive understanding of these RNA chemical modifications and their implications for virus–host interactions is essential for advancing therapeutic strategies aimed at manipulating innate immunity and optimizing the efficacy of RNA-based vaccines. This review examines the mechanisms and implications of RNA chemical modifications in negative-sense RNA viruses, emphasizing their dual roles in either evading or activating the innate immune system. Full article

Background/Objectives: Exposure of high-fat diet (HFD)-fed mice to polychlorinated biphenyls (PCBs) results in metabolic dysfunction-associated steatotic liver disease (MASLD) and progression to metabolic dysfunction-associated steatohepatitis (MASH). The mechanisms by which HFD diet and PCBs increase MASLD are unclear. Previously, we identified differences in HFD-fed mouse liver tRNA modifications with single oral exposures to the dioxin-like PCB126, the non-dioxin-like PCB mixture Aroclor 1260 (Ar1260), or the combination of Ar1260 + PCB126. Methods: Here, we used small RNA sequencing and the tRNA analysis of expression (tRAX) pipeline to examine if PCB exposures alter the tRNA transcriptome, including tRNA-derived fragments (tRFs), in the livers of the PCB-exposed mice. Results: Each PCB exposure produced distinct hepatic tRNA transcriptomes with more tRNAs decreased than increased. Only tRNA-Glu-TTC-1 was reduced with all three PCB exposures. More changes in tRFs were identified with Ar1260 alone or in combination with PCB126 than with PCB126 alone. Four tRF-3s were upregulated in both PCB126 and Ar1260 + PCB126 co-exposed mice, suggesting PCB126 as responsible for this increase. We previously reported that PCB126 exposure increased hepatic Angiogenin (ANG) protein which generates tRF-3s. Four previously reported tRNA modifications corresponded to positions of PCB-associated tRNA modifications identified by tRAX: m1A, m6A, ms2t6A, and Ψ. Conclusions: Overall, the differences in hepatic tRNAs and tRFs with three different PCB exposures suggest that PCB exposures play an unexplored role in regulating translation in mouse liver. Full article