Search Results (1,179)

Background/Objectives: Drug repurposing has emerged as a promising strategy for identifying novel anticancer agents among clinically established drugs. Fexofenadine, a second-generation H1 antihistamine, has been proposed as a candidate for repurposing in oncology; however, the molecular mechanisms underlying its biological activity remain insufficiently characterized. This study investigated the effects of fexofenadine on oxidative stress, mitochondrial function, apoptosis, and pro-survival signaling pathways in cervical and lung cancer cells. Methods: HeLa and A549 cancer cells, as well as non-tumorigenic Beas-2B epithelial cells, were exposed to fexofenadine under in vitro conditions. Cell viability, apoptosis, reactive oxygen species generation, mitochondrial membrane potential, DNA damage, autophagy-associated responses, and PI3K/AKT and MAPK/ERK pathway activation were assessed using flow cytometry, fluorescence microscopy, electron microscopy, and biochemical assays. Three-dimensional spheroid cultures and N-acetyl-L-cysteine rescue experiments were additionally employed to evaluate biological relevance and the contribution of oxidative stress. Results: Fexofenadine induced concentration-dependent accumulation of reactive oxygen species, mitochondrial membrane depolarization, Bcl-2 inactivation, caspase-3/7 activation, DNA damage, and apoptotic cell death in HeLa and A549 cells. Antioxidant pretreatment with N-acetyl-L-cysteine significantly reduced oxidative stress, attenuated mitochondrial dysfunction, and partially suppressed apoptosis. Fexofenadine was associated with reduced PI3K/AKT and MAPK/ERK pathway activation and promoted autophagy-associated responses. In three-dimensional spheroid cultures, treatment disrupted spheroid integrity and increased apoptotic cell death. Non-tumorigenic Beas-2B cells exhibited lower sensitivity to treatment than malignant cells. Conclusions: Fexofenadine disrupts redox homeostasis and is associated with reduced activation of pro-survival signaling pathways, resulting in oxidative stress-associated mitochondrial dysfunction and apoptosis in cancer cells. These findings provide mechanistic support for further evaluation of fexofenadine as a candidate for anticancer drug repurposing, while additional pharmacokinetic and in vivo studies are required to determine its translational relevance. Full article

Major depressive disorder (MDD) is not reducible to a single neurotransmitter deficit. Current explanations commonly involve monoaminergic dysfunction, hypothalamic–pituitary–adrenal axis dysregulation, immune-inflammatory activation, impaired neuroplasticity and synaptic dysfunction, together with metabolic and neurovascular abnormalities. Lipidomic studies have repeatedly identified glycerophospholipid abnormalities in MDD, but their mechanistic meaning remains unresolved because changes in bulk lipid abundance do not explain how altered lipid metabolism becomes a receptor-level neural signal. This review develops a testable interpretation of the lysophosphatidylcholine (LPC)–autotaxin (ATX)–lysophosphatidic acid (LPA)–LPA receptor (LPAR) axis in which LPC species generated during phospholipid turnover provide ATX substrates, ATX activity determines local LPA generation, LPA production and inactivation shape ligand availability, and LPAR signaling links the lipid product to neural output. This structure shifts the focus from total lipid abundance to matched assessment of lipid species, enzyme activity, anatomical site and receptor subtype. Human studies report lower serum and cerebrospinal fluid (CSF) ATX in MDD, lower CSF LPA 22:6 in MDD and schizophrenia, and negative total LPA findings that caution against biomarker oversimplification. Depression-relevant and broader stress- or anxiety-related experimental studies show that ATX, LPA and LPAR perturbation can affect hippocampal function, synaptic physiology, emotional behavior and stress resilience. The key unresolved issue is whether brain-accessible LPC species, active ATX, locally generated LPA, LPA inactivation capacity and receptor-specific output can be demonstrated within the same MDD-relevant fluid, brain-interface site or neural circuit. Future work should therefore move from fluid-level association toward pathway closure through targeted and spatial lipidomics, anatomical ATX activity mapping, LPA inactivation assays, blood–brain barrier (BBB)/interface analysis, LPAR perturbation and matched circuit or behavioral readouts. Full article

Retroviruses induce immunosuppression in their infected hosts. This phenomenon is well described for the immunodeficiency viruses, with human immunodeficiency virus type 1 (HIV-1) representing the best-studied example, but it also occurs in other retroviral infections. Immunosuppressive properties were first characterized in murine leukemia viruses (MuLV). Additional well-studied examples include feline leukemia virus (FeLV) and koala retrovirus (KoRV). Investigations into the mechanisms underlying retrovirus-induced immunosuppression revealed that not only inactivated viral particles but also their purified transmembrane (TM) envelope proteins exhibit immunosuppressive activity. However, in certain retroviral infections, additional viral proteins contribute to the immunosuppression in vivo. Within the TM envelope proteins, a highly conserved region—designated the immunosuppressive (isu) domain—was identified. Synthetic peptides corresponding to this domain suppress a wide range of in vitro immune responses, possibly by regulating Ras-Raf-MEK-MAPK and PI3K-AKT-mTOR pathways. They modulate cytokine release and alter gene expression in immune cells, mirroring the activity of the corresponding TM envelope protein. Mutations in the sequence abrogate the effect. Numerous TM envelope proteins have demonstrated immunosuppressive activity in vivo in a tumor rejection model, and mutations within the isu domain also abrogate this function. These studies have important implications for reproduction, particularly through the immunosuppressive syncytins in the placenta, for tumor development, where similar mechanisms may protect cancer cells from the host immune system, and for vaccine development and xenotransplantation. Notably, immunization with TM envelope proteins carrying mutations in the isu domain elicits stronger immune responses compared with the wild-type proteins. Finally, the potential of retroviral TM envelope proteins to protect xenotransplants from immune rejection will be discussed. Full article

Mitochondrial diseases have traditionally been viewed as energy deficiencies, but current evidence positions mitochondria as central regulators of multiple cell death pathways. This review systematically analyzes the molecular mechanisms of apoptosis and ferroptosis in the context of both primary mitochondrial diseases—caused by mutations in mtDNA or nuclear DNA directly affecting oxidative phosphorylation—and secondary mitochondrial dysfunction associated with broader pathological conditions. Apoptosis is an energy-dependent process characterized by mitochondrial outer membrane permeabilization, cytochrome c release, and caspase cascade activation, whereas ferroptosis involves iron-dependent lipid peroxidation, glutathione depletion, and inactivation of glutathione peroxidase 4 (GPX4), leading to accumulation of oxidized phospholipids predominantly in endoplasmic reticulum and plasma membranes; mitochondrial ultrastructural changes—including volume reduction and cristae loss—represent characteristic morphological features of ferroptosis rather than its primary site of initiation. Key findings reveal that reactive oxygen species overproduction, disruption of reducing equivalent metabolism, iron dyshomeostasis, and calcium overload simultaneously prime cells for both death pathways. Cytochrome c, p53, and BCL-2 family proteins serve as integration hubs, with cardiolipin peroxidation and phospholipid composition influencing pathway switching. Tissue specificity is pronounced in primary mitochondrial diseases: retinal ganglion cells in Leber’s hereditary optic neuropathy, cardiomyocytes in mtDNA-associated cardiomyopathies, and hepatocytes in mtDNA depletion syndromes exhibit distinct dominant death pathways. It should be noted, however, that for many conditions discussed, the evidence for ferroptosis involvement relies on indirect markers—such as lipid peroxidation products, decreased GPX4, and iron deposition—rather than on pharmacological rescue with ferrostatin-1 or liproxstatin-1 and rigorous exclusion of alternative death modalities; this limitation is discussed critically throughout the review. Diagnostic criteria combining morphological, biochemical, and pharmacological tools enable differentiation of death pathways. The review concludes that combined inhibition—using mitochondria-targeted antioxidants, GPX4 modulators, iron chelators, and mPTP blockers—together with personalized diagnostic algorithms offers the most promising therapeutic strategy. Understanding the apoptosis–ferroptosis crosstalk is essential for developing targeted interventions in mitochondrial diseases. Full article

Gemcitabine-based chemotherapy has long served as a standard treatment for urothelial carcinoma (UC), particularly in perioperative and metastatic settings. However, therapeutic efficacy is frequently limited by intrinsic or acquired resistance. Gemcitabine functions as a prodrug whose activity depends on coordinated processes involving cellular uptake, intracellular activation, metabolic inactivation, and nucleotide metabolism. Increasing evidence suggests that resistance in UC is mediated by multiple interconnected mechanisms beyond alterations in gemcitabine transport, activation, and inactivation alone. Key molecular determinants include human equilibrative nucleoside transporter 1 (hENT1), deoxycytidine kinase (dCK), cytidine deaminase (CDA), and ribonucleotide reductase regulatory subunit M1 (RRM1), which is involved in nucleotide pool maintenance and DNA synthesis. In addition, replication stress responses, apoptosis evasion pathways, and tumor microenvironment-associated factors also contribute to gemcitabine resistance. Stress-adaptive pathways involving Y-box binding protein 1 (YB-1), hypoxia-inducible factor-1 alpha (HIF-1α), and autophagy-related mechanisms may further promote survival under chemotherapy-induced stress conditions. In addition, extracellular mucin-associated mechanisms may alter intratumoral drug accessibility and contribute to resistance. In this review, we summarize UC-specific evidence regarding gemcitabine resistance and discuss how these pathways collectively shape an integrated resistant phenotype. Full article

Background/Objectives: Functional constipation (FC) commonly affects middle-aged and older adults, but current pharmacological treatments have limitations. Postbiotics may offer safety advantages, but clinical evidence is limited. This randomized controlled trial evaluated the efficacy and safety of a heat-inactivated two-strain Lacticaseibacillus paracasei fermented milk in adults with FC. Methods: One hundred adults aged 45–75 years with Rome IV-defined FC received the fermented milk or placebo for 4 weeks. The primary outcome was the change in weekly spontaneous bowel movement (SBM) frequency from baseline to week 4. Secondary outcomes included complete spontaneous bowel movement (CSBM) frequency, whole-gut transit time (WGTT), constipation symptom scores, quality of life, serum biomarkers, and adverse events. Primary analysis was per-protocol (n = 96); intention-to-treat analysis was applied to primary and key secondary outcomes. Results: Dropout was 4% (n = 4, 2 per group), and adherence was >80% in both groups. The intervention showed no significant benefit over placebo for the primary outcome or for most secondary clinical outcomes. Although both groups improved within-group, no significant between-group differences were observed at week 4 for changes in SBM (MD = −0.14, 95% CI: −0.85, 0.57; p = 0.683), CSBM (MD = 0.27, 95% CI: −0.61, 1.15; p = 0.543), or WGTT (MD = −1.55 h, 95% CI: −7.65, 4.55; p = 0.614). Symptom and quality-of-life scores also did not differ between groups. Exploratory biomarker analyses showed significantly greater increases in serum VIP and ACh in the intervention group (VIP: MD = 105.23 ng/L, p < 0.001; ACh: MD = 42.95 ng/L, p = 0.035). No adverse events were reported. Conclusions: Four weeks of this postbiotic was safe but did not significantly improve bowel function or symptoms in the overall FC population. The increases in serum VIP and ACh suggest engagement of neurotransmitter-related pathways; however, these exploratory findings do not imply causation or clinical efficacy and warrant confirmation in longer-duration trials (Clinical Trial Registry: ChiCTR2500111771). Full article

N-acetylserotonin methyltransferase (ASMT) is among the key enzymes involved in the final steps of melatonin biosynthesis. Here, we have shown that inactivation of ASMT in A. thaliana results in reduced endogenous melatonin levels, modulating other plant hormone pathways and affecting stress-related responses. Transcriptomic analysis of the asmt-null mutant revealed that the differentially expressed genes were predominantly enriched in terms associated with auxin responses and signalling, as well as with abscisic acid (ABA)-mediated stress responses. In addition, the expression of genes involved in the ethylene, salicylic acid, jasmonic acid and brassinosteroid pathways was altered in the mutant. Assays of a β-glucuronidase (GUS) construct in which a fragment containing 1000 bp upstream of the ASMT start codon was fused to the GUS reporter gene confirmed that ASMT is involved in the responses to ABA, gibberellic and indole acetic acids, trans-zeatin, ethylene and epibrassinolide, which is consistent with the results of the in silico analysis of the ASMT promoter. Furthermore, the expression of a number of genes, such as SLG1, HIS1-3, AtAIRP1 and several LEA genes, whose transcriptional regulation is associated with water management and contributes to impaired tolerance to dehydration stress, was altered in the mutant. The pleiotropic effects of ASMT gene disruption facilitate the identification of new potential melatonin targets and provide insights into the specific mechanisms of melatonin action. Full article

Antibiotic-resistant bacteria are widely distributed and threaten public health. Photocatalytic antimicrobial technology can effectively inactivate multidrug-resistant bacteria without readily inducing resistance. We previously showed that oxygen-rich vacancy Bi₂MoO₆ (OBM) exhibits excellent activity against methicillin-resistant Staphylococcus aureus (MRSA), but the underlying molecular mechanisms remain poorly understood. Here, we employed integrated transcriptomics and metabolomics, with qRT-PCR validation, to systematically elucidate the antibacterial mechanism of OBM against MRSA. OBM treatment induced profound transcriptional and metabolic alterations: 231 differentially expressed genes and 206 differentially abundant metabolites were identified. Functional enrichment analysis revealed cooperative involvement in multiple critical pathways, including inhibition of amino acid biosynthesis and protein translation, disruption of cell wall and membrane integrity, induction of oxidative stress, collapse of energy metabolism (suppression of oxidative phosphorylation and impaired ATP synthesis), and imbalance in nucleotide metabolism (down-regulation of DNA helicase and mismatch repair genes, dysregulation of purine/pyrimidine metabolism). These findings demonstrate that OBM photocatalytically inactivates MRSA through a multi-target systemic attack at both the transcriptional and metabolic levels, providing a novel theoretical foundation for the development of photocatalytic materials aimed at controlling MRSA and other drug-resistant bacteria. Full article

Background: Adipose tissue is increasingly recognized as a highly dynamic endocrine and immunometabolic organ with marked functional heterogeneity. It serves as a reservoir for the active form of vitamin D₃, 1α,25-dihydroxyvitamin D₃ or calcitriol (1α,25-D₃), since it expresses enzymes responsible for its activation and inactivation and contains the vitamin D receptor (VDR). Through both classical and non-classical mechanisms, calcitriol modulates adipocyte proliferation and differentiation, protein expression and energy metabolism. This review aims to explore the signal transduction mechanisms of calcitriol in adipocytes, detailing the classical pathways mediated by the nuclear VDR (VDRn), as well as non-classical pathways involving membrane-associated VDR (VDRm), microRNAs, AMP-activated protein kinase (AMPK), and sirtuin 1 (SIRT1). Methods: A literature search was conducted using PubMed, ScienceDirect, and MDPI-indexed journals, prioritizing studies published within the last 10 years to ensure the inclusion of up-to-date evidence. Results: This review summarizes current knowledge on both classical and non-classical signaling pathways that are activated by calcitriol and highlights key molecular targets with potential relevance for drug development and therapeutic intervention. Through VDRn, calcitriol regulates the expression of proteins involved in inflammation and energy metabolism. Additionally, it modulates cellular processes such as energy production and secretion via the AMPK/SIRT1 axis and microRNA-mediated pathways, contributing to mitochondrial function and metabolic homeostasis. Conclusions: Calcitriol plays a central role in adipocyte biology by integrating multiple signaling pathways that regulate metabolic and inflammatory responses. These mechanisms highlight its potential as a therapeutic target and biomarker in metabolic diseases. Moreover, microRNAs emerge as critical posttranscriptional regulators in these processes, reinforcing their relevance as both biomarkers and targets for future interventions. Full article

Invertebrates rely exclusively on innate immunity but exhibit memory-like responses termed immune priming or trained immunity. In the commercially vital whiteleg shrimp (Litopenaeus vannamei), infection by Vibrio parahaemolyticus causes severe economic losses, yet the molecular networks driving secondary immune recall remain poorly understood. In this study, we established a two-step immune challenge model in L. vannamei using formaldehyde-inactivated V. parahaemolyticus and performed transcriptomic analysis on hemocytes to compare primary and secondary immune responses. Differentially expressed gene (DEG) screening and enrichment analyses (GO, KEGG, and GSEA) suggest that shrimp hemocytes undergo a broad and coordinated transcriptional reprogramming rather than uniform upregulation of immune genes. Transcriptomic data show potential associations between secondary immune priming and the modulation of cell fate processes: genes related to cell cycle progression (e.g., CDK1, CCNB3) and spindle assembly (e.g., MPS1) were significantly upregulated alongside apoptosis inhibition (CASP6 downregulation). Concurrently, metabolic remodeling was observed through the upregulation of lipid synthesis (SREBF1, FASN) and carbohydrate uptake pathways, potentially providing anabolic support for hemocyte growth and immune activation. Furthermore, the humoral effector responses appear to be strengthened, characterized by upregulated antimicrobial peptides (PEN, ALF) and the proPO melanization cascade (PPAF3, PPO3), whereas the expression of intracellular NLR was relatively suppressed, which might help mitigate excessive immune inflammation and immunopathological damage. Collectively, these transcriptomic findings identify a putative coordinated transcriptional signature of hemocyte recall responses in L. vannamei. This study expands our understanding of innate immune memory in invertebrates and provides candidate molecular markers for further study in disease-resistant breeding research in shrimp aquaculture. Full article

Proactive disease transmission pathway analyses break complex transmission routes into simpler steps, making risks and uncertainties easier to identify. This approach is especially valuable for African Swine Fever (ASF), a difficult-to-control disease in low-biosecurity settings or when biosecurity practices are inconsistently applied. To support targeted biosecurity planning, a pathway analysis was conducted that is specific to pork harvest facilities in the United States. The analysis focused on two federally inspected plants that slaughter market hogs and produce primal cuts. Inputs, outputs, and potential transmission pathways were identified through a literature review, site visits, and facility personnel interviews. Because ASF virus remains stable at low temperatures and in many pork products, particular attention was given to pathways involving storage conditions, waste materials, and processing steps such as heating or pH modification. Processing steps were evaluated against existing process control plans and ASF inactivation thresholds to determine mitigation status. Of 42 identified pathways, 39 were classified as unmitigated or of unknown mitigation status. These unmitigated or unknown pathways—broadly involving pigs, people, vehicles, and waste—represent the highest priorities for further risk assessment work and for exploring ways to develop or strengthen biosecurity protocols that reduce ASF transmission. Full article

4-Ethylguaiacol (4-EG) is a volatile phenolic compound associated with smoky, woody, and spicy aroma notes in fermented foods and beverages, including Baijiu. In this study, a 4-EG-producing strain, designated JN11, was obtained by screening isolates from Baijiu pit mud and identified as Bacillus coagulans based on morphological, physiological, biochemical, and 16S rRNA analyses. In sorghum juice medium, strain JN11 produced 271.6 ± 2.7 μg/L 4-EG. To investigate the upstream decarboxylation step involved in volatile phenol formation, the phenolic acid decarboxylase gene, BcPAD, was cloned and heterologously expressed in Escherichia coli BL21(DE3). The BcPAD gene comprises 504 bp and encodes a 167-amino-acid protein. Recombinant BcPAD exhibited maximal activity at pH 6.0 and 50 °C and retained more than 60% residual activity after 5 h at 30–40 °C. Fe³⁺ increased enzyme activity to 115.36% of the control, whereas Zn²⁺ markedly inhibited enzyme activity and SDS completely inactivated the enzyme. BcPAD showed the highest activity toward p-coumaric acid, with a specific activity of 460.6 ± 18.3 U/mg and a catalytic efficiency (Kcat/Km) of 12.1 ± 1.4 mM⁻¹·s⁻¹, while lower activities were observed toward caffeic acid and ferulic acid, and no activity was detected toward sinapic acid. Homology modeling and molecular docking suggested that the superior catalytic performance toward p-coumaric acid may be related to favorable hydrogen-bonding interactions and substrate orientation within the active site. Although 4-EG production was observed during fermentation by strain JN11, BcPAD was biochemically characterized as a phenolic acid decarboxylase likely responsible for the upstream formation of vinyl derivatives in the proposed pathway. These findings improve our understanding of phenolic acid decarboxylases from B. coagulans and provide a basis for further investigation of the roles of strain JN11 and BcPAD in volatile phenol formation during Baijiu production. Full article

Target of rapamycin (TOR) is a conserved protein kinase that integrates nutrient and energy signals to control growth and metabolism, yet its proteome-level impact in microalgae remains poorly understood. Here, we conducted quantitative proteomics analysis of the unicellular red alga Cyanidioschyzon merolae under rapamycin-induced TOR inactivation to characterize global changes in protein abundance. TOR inhibition triggered widespread metabolic remodeling, including coordinated shifts in carbon and nitrogen allocation, and pronounced changes in protein synthesis, photosynthesis, and energy metabolism. Specifically, proteins associated with ribosome biogenesis and ribosomal subunits declined broadly, indicating impaired translation, alongside pronounced reductions in photosynthetic components, including PSI/PSII subunits and chlorophyll biosynthesis enzymes. In contrast, triacylglycerol (TAG) biosynthesis and starch metabolism were enhanced, indicating a shift towards carbon storage. Notably, a diacylglycerol acyltransferase (DGAT; CMQ199C) and a UDP-glucose pyrophosphorylase (UGP; CMS159C) were strongly induced (2.02-fold and 3.48-fold, respectively), identifying them as candidate targets for enhancing TAG and starch accumulation. Proteins associated with nitrogen assimilation were also upregulated, supporting TOR-dependent regulation of nitrogen metabolism at the protein level. Together, these results indicate that TOR orchestrates proteome-level reprogramming in C. merolae, coordinating growth, energy production, and carbon storage across interconnected metabolic pathways. Full article

Autophagy is a conserved catabolic process that degrades damaged proteins and organelles to preserve cellular homeostasis. Autophagy plays two opposing roles during viral infection. On the one hand, it can be subverted by viruses to facilitate replication and immune evasion. On the other hand, it limits viral infection by delivering viral components to lysosomes. The interaction between autophagy and important picornaviruses that infect cattle and poultry, such as SVV, EMCV, FMDV, and DHAV, is the main topic of this paper. However, comprehensive summaries focusing specifically on livestock and poultry remain limited. We summarize current research showing that these viruses evade host protection by manipulating several steps of the autophagic pathway, from initiation to lysosomal fusion, to produce replication-favorable environments. Notably, by directing the breakdown of viral capsid proteins, specific autophagy receptors such as SQSTM1/p62, NDP52, and optineurin (OPTN) serve as antiviral effectors. In response, picornaviruses have developed proteolytic strategies to inactivate these receptors, such as SVV 3C-mediated cleavage of SQSTM1 and OPTN. Moreover, different immune evasion tactics are shown by virus-specific engagement of organelle-selective autophagy, such as ER-phagy (SVV) or mitophagy (DHAV). The development of broad-spectrum antiviral treatments and autophagy-based biomarkers for livestock disease progression may benefit from an understanding of the convergent and different ways picornaviruses take advantage of the autophagic machinery. Full article

Vibrio splendidus is an important opportunistic pathogen that causes diseases in aquatic animals, and its persisters increase the difficulty of aquaculture disease control. The stringent response is a central pathway in bacteria for coping with environmental stress, and the signaling molecule (p)ppGpp, synthesized under the regulation of RelA/SpoT homologs, is closely associated with persister formation and virulence modulation. However, the regulatory mechanisms linking the stringent response to persister formation and virulence in V. splendidus remain unclear. In this study, the core gene deletion strains ΔrelA and ΔrelAΔspoT were constructed via homologous recombination. Combined with D₂O single-cell Raman spectroscopy, transcriptomics, and phenotypic assays, we systematically characterized the biological effects of stringent response inactivation. The results showed that the loss of relA and spoT significantly reduced persister formation and key virulence traits while enhancing biofilm formation. Single-cell Raman spectroscopy analysis indicated that persisters remained metabolically active, accompanied by changes in different cellular components. Transcriptome analysis revealed that the absence of stringent response affected multiple pathways, including ribosomal function, energy metabolism, two-component systems, and quorum sensing. Additionally, the sigma factor RpoS may potentially exert a compensatory function in ΔrelAΔspoT strain, but this requires further validation. In conclusion, the stringent response positively regulates persister formation and virulence in V. splendidus, despite the existence of complex regulatory mechanisms. This study provides a theoretical basis for the development of anti-infective strategies targeting stringent response in aquatic pathogens. Full article