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12 pages, 3854 KB  
Article
Crosstalk of Tumor-Derived Extracellular Vesicles with Immune Recipient Cells and Cancer Metastasis
by Han Jie, Alicja C Gluszko and Theresa L. Whiteside
Cancers 2026, 18(2), 196; https://doi.org/10.3390/cancers18020196 - 7 Jan 2026
Abstract
Background. Contributions of tumor-derived extracellular vesicles, TEX, to tumor progression and metastasis involve their crosstalk with immune cells in the tumor microenvironment. This crosstalk results in metabolic reprogramming of immune cells from anti-tumor to pro-tumor activity. Mechanistic underpinnings of the TEX entry [...] Read more.
Background. Contributions of tumor-derived extracellular vesicles, TEX, to tumor progression and metastasis involve their crosstalk with immune cells in the tumor microenvironment. This crosstalk results in metabolic reprogramming of immune cells from anti-tumor to pro-tumor activity. Mechanistic underpinnings of the TEX entry and delivery of molecular signals responsible for metabolic reprogramming may be unique for different types of immune cells. Methods. An in vitro model of THP-1 myeloid cells co-incubated with TEX illustrates the role TEX play in polarization of macrophages to TAMs. Results. In THP-1 cells, the dominant signaling pathway of melanoma cell-derived TEX involves HSP-90/TLR2. This leads to activation of the NF-κB and MAP kinase pathways and initiates THP-1 cell polarization from M0 to M2 with strong expression of immunosuppressive PD-L1. TEX may be seen as “danger” by the myeloid cells, which utilize the pattern recognition receptors (PRR), such as PAMPs or DAMPs, for engaging the complementary ligands carried by TEX. The same melanoma TEX signaling to T cells via DAMPs induced mitochondrial stress, resulting in T-cell apoptosis. Conclusions. As the signaling receptors/ligands in TEX are determined by the tumor, it appears that the tumor equips TEX with an address recognizing specific PRRs expressed on different recipient immune cells. Thus, TEX, acting like pathogens, are equipped by the tumor to alter the context of intercellular crosstalk and impose a distinct autophagy-not-apoptosis signature in recipient THP-1 cells. The tumor might endorse TEX to promote tumor progression and metastasis by enabling them to engage the signaling system normally used by immune cells for defense against pathogens. Full article
(This article belongs to the Special Issue Exosomes in Cancer Metastasis (2nd Edition))
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34 pages, 48857 KB  
Article
In Silico Prediction of Potential pTLR7/pSTING Dual-Targeting Ligands via Virtual Screening and Molecular Dynamics Simulation
by Chang Liu, Zhe Qin, Lixia Bai, Xiao Xu, Wenbo Ge, Zhun Li and Jianyong Li
Int. J. Mol. Sci. 2026, 27(1), 338; https://doi.org/10.3390/ijms27010338 - 28 Dec 2025
Viewed by 198
Abstract
Toll-like receptor 7 (TLR7) and Stimulator of Interferon Genes (STING) ligands possess a series of immunomodulatory effects such as anti-infection, anti-tumor, and autoimmune-disease-alleviating effects. In this study, porcine TLR7 (pTLR7) and porcine STING (pSTING) were selected as targets, and molecular docking and virtual [...] Read more.
Toll-like receptor 7 (TLR7) and Stimulator of Interferon Genes (STING) ligands possess a series of immunomodulatory effects such as anti-infection, anti-tumor, and autoimmune-disease-alleviating effects. In this study, porcine TLR7 (pTLR7) and porcine STING (pSTING) were selected as targets, and molecular docking and virtual screening methods were used for screening of dual-target livestock immunomodulators. Finally, two compounds were screened with molecular docking scores higher than the positive control compounds. They have good binding ability with pTLR7 and pSTING proteins, as well as satisfactory predictive safety and pharmacokinetic properties. Molecular dynamics (MD) simulation results also indicated that the above ligands can form stable complexes with two target proteins. The average binding free energies of compound 2 with pTLR7 and pSTING were −28.65 kcal/mol and −30.12 kcal/mol, respectively, and of compound 7 with pTLR7 and pSTING were −35.93 kcal/mol and −31.70 kcal/mol, respectively, which were comparable to that of positive control ligands. The similarity of target proteins between pigs, humans, and mice, as well as the interactions between ligands and TLR7 and STING in different species, were analyzed. And analysis of predicted structure–activity relationship (SAR) was conducted. Briefly, compound 2 and compound 7 were predicted to form stable complexes with pTLR7 and pSTING, with satisfactory predicted physicochemical properties and pharmacokinetic characteristics, and represented candidates for experimental validation. This study supplies a research basis for the development, design, and structural modification of immune enhancers for animals. Full article
(This article belongs to the Section Molecular Immunology)
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29 pages, 3722 KB  
Review
Glial Cells in the Early Stages of Neurodegeneration: Pathogenesis and Therapeutic Targets
by Eugenia Ahremenko, Alexander Andreev, Danila Apushkin and Eduard Korkotian
Int. J. Mol. Sci. 2025, 26(24), 11995; https://doi.org/10.3390/ijms262411995 - 12 Dec 2025
Viewed by 723
Abstract
Astrocytes and microglia constitute nearly half of all central nervous system cells and are indispensable for its proper function. Both exhibit striking morphological and functional heterogeneity, adopting either neuroprotective (A2, M2) or proinflammatory (A1, M1) phenotypes in response to cytokines, pathogen-associated molecular patterns [...] Read more.
Astrocytes and microglia constitute nearly half of all central nervous system cells and are indispensable for its proper function. Both exhibit striking morphological and functional heterogeneity, adopting either neuroprotective (A2, M2) or proinflammatory (A1, M1) phenotypes in response to cytokines, pathogen-associated molecular patterns (PAMPs)/damage-associated molecular patterns (DAMPs), toll-like receptor 4 (TLR4) activation, and NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome signaling. Crucially, many of these phenotypic transitions arise during the earliest stages of neurodegeneration, when glial dysfunction precedes overt neuronal loss and may act as a primary driver of disease onset. This review critically examines glial-centered hypotheses of neurodegeneration, with emphasis on their roles in early disease phases: (i) microglial polarization from an M2 neuroprotective state to an M1 proinflammatory state; (ii) NLRP3 inflammasome assembly via P2X purinergic receptor 7 (P2X7R)-mediated K+ efflux; (iii) a self-amplifying astrocyte–microglia–neuron inflammatory feedback loop; (iv) impaired microglial phagocytosis and extracellular-vesicle–mediated propagation of β-amyloid (Aβ) and tau; (v) astrocytic scar formation driven by aquaporin-4 (AQP4), matrix metalloproteinase-9 (MMP-9), glial fibrillary acidic protein (GFAP)/vimentin, connexins, and janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) signaling; (vi) cellular reprogramming of astrocytes and NG2 glia into functional neurons; and (vii) mitochondrial dysfunction in glia, including Dynamin-related protein 1/Mitochondrial fission protein 1 (Drp1/Fis1) fission imbalance and dysregulation of the sirtuin 1/peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Sirt1/PGC-1α) axis. Promising therapeutic strategies target pattern-recognition receptors (TLR4, NLRP3/caspase-1), cytokine modulators (interleukin-4 (IL-4), interleukin-10 (IL-10)), signaling cascades (JAK2–STAT, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), phosphoinositide 3-kinase–protein kinase B (PI3K–AKT), adenosine monophosphate-activated protein kinase (AMPK)), microglial receptors (triggering receptor expressed on myeloid cells 2 (TREM2)/spleen tyrosine kinase (SYK)/ DNAX-activating protein 10 (DAP10), siglec-3 (CD33), chemokine C-X3-C motif ligand 1/ CX3C motif chemokine receptor 1 (CX3CL1/CX3CR1), Cluster of Differentiation 200/ Cluster of Differentiation 200 receptor 1 (CD200/CD200R), P2X7R), and mitochondrial biogenesis pathways, with a focus on normalizing glial phenotypes rather than simply suppressing pathology. Interventions that restore neuroglial homeostasis at the earliest stages of disease may hold the greatest potential to delay or prevent progression. Given the complexity of glial phenotypes and molecular isoform diversity, a comprehensive, multitargeted approach is essential for mitigating Alzheimer’s disease and related neurodegenerative disorders. This review not only synthesizes pathogenesis but also highlights therapeutic opportunities, offering what we believe to be the first concise overview of the principal hypotheses implicating glial cells in neurodegeneration. Rather than focusing on isolated mechanisms, our goal is a holistic perspective—integrating diverse glial processes to enable comparison across interconnected pathological conditions. Full article
(This article belongs to the Special Issue Early Molecular Markers of Neurodegeneration)
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17 pages, 3320 KB  
Article
Genome-Wide Identification, Characterization, and Expression Profiles of TLR Genes in Darkbarbel Catfish (Pelteobagrus vachelli) Following Aeromonas hydrophila Infection
by Zhengyong Wen, Lisha Guo, Jianchao Chen, Qiyu Chen, Yanping Li, Yunyun Lv, Qiong Shi and Shengtao Guo
Biology 2025, 14(12), 1724; https://doi.org/10.3390/biology14121724 - 1 Dec 2025
Viewed by 414
Abstract
Toll-like receptors (TLRs) are central to pathogen recognition in teleost innate immunity. In this study, we surveyed 41 genomes from four representative teleost orders (i.e., Cypriniformes, Siluriformes, Perciformes, and Pleuronectiformes) for 15 TLR genes (TLR1–9, 12, 13, 18, 20–22) revealed a [...] Read more.
Toll-like receptors (TLRs) are central to pathogen recognition in teleost innate immunity. In this study, we surveyed 41 genomes from four representative teleost orders (i.e., Cypriniformes, Siluriformes, Perciformes, and Pleuronectiformes) for 15 TLR genes (TLR1–9, 12, 13, 18, 20–22) revealed a conserved core (TLR2/3/7 in nearly all examined species) alongside lineage-specific losses (TLR4/9/18/20/21/22), indicating both strong conservation and dynamic diversification of the TLR repertoire. We further identified and characterized 12 TLR genes in economically important darkbarbel catfish (Pelteobagrus vachellii). Corresponding cDNAs span 2089–4456 bp and encode proteins of 789–1,087 aa, with canonical extracellular LRR arrays and C-terminal TIR domains but notable “non-classical” features (such as absence of signal peptides in TLR1/13; no transmembrane segment in TLR7; multiple transmembranes in TLR3/8/13/18/22), suggesting subcellular and functional heterogeneity of various TLR genes. Subsequent gene-structure comparisons uncovered gene-specific exon–intron organizations and variable UTR lengths, implicating differential post-transcriptional regulation. Predicted 3D structures retain the traditional hallmark LRR horseshoe fold with subtle variations potentially tuning ligand specificity. Genomic synteny with Pseudobagrus ussuriensi and Pangasianodon hypophthalmus reveals conserved chromosomal organization, and phylogeny construction resolves each TLR subtype into well-supported monophyletic clades, which underscore evolutionary stability. Functionally, exogenous Aeromonas hydrophila challenge triggered rapid, tissue-dependent TLR up-regulation in the kidney, liver, and especially gill (with some transcripts > 1000-fold), highlighting coordinated mucosal and systemic surveillance in darkbarbel catfish. Taken together, these valuable data provide a comprehensive framework for the structural, evolutionary, and inducible expression landscape of catfish TLRs and establish a foundation for in-depth studies on antibacterial immunity in diverse teleost species. Full article
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38 pages, 1595 KB  
Review
The Role of Toll-like Receptors and Viral Infections in the Pathogenesis and Progression of Pulmonary Arterial Hypertension—A Narrative Review
by Agnieszka Styczeń, Martyna Krysa, Paulina Mertowska, Ewelina Grywalska, Tomasz Urbanowicz, Maciej Krasiński, Malwina Grobelna, Weronika Topyła-Putowska, Mansur Rahnama-Hezavah and Michał Tomaszewski
Int. J. Mol. Sci. 2025, 26(22), 11143; https://doi.org/10.3390/ijms262211143 - 18 Nov 2025
Viewed by 1092
Abstract
Aberrant activation of innate immunity promotes the development of pulmonary arterial hypertension (PAH); however, the role of pattern recognition by Toll-like receptors (TLRs) within the pulmonary vasculature remains unclear. To consolidate knowledge (as of June 2025) about TLRs and their interactions with viruses [...] Read more.
Aberrant activation of innate immunity promotes the development of pulmonary arterial hypertension (PAH); however, the role of pattern recognition by Toll-like receptors (TLRs) within the pulmonary vasculature remains unclear. To consolidate knowledge (as of June 2025) about TLRs and their interactions with viruses in PAH and to identify therapeutic implications. A narrative review of experimental and clinical studies investigating ten TLRs in the context of the pulmonary vascular microenvironment and viral infections. Activation of TLR1/2, TLR4, TLR5/6, TLR7/8, and TLR9 converges on the MyD88–NF-κB/IL-6 axis, thereby enhancing endothelial-mesenchymal transition, smooth muscle proliferation, oxidative stress, thrombosis, and maladaptive inflammation, ultimately increasing pulmonary vascular resistance. Conversely, TLR3, through TRIF–IFN-I, preserves endothelial integrity and inhibits vascular remodeling; its downregulation correlates with PAH severity, and poly (I:C) restitution has been shown to improve hemodynamics and right ventricular function. HIV-1, EBV, HCV, endogenous retrovirus K, and SARS-CoV-2 infections modulate TLR circuits, either amplifying pro-remodeling cascades or attenuating protective pathways. The “TLR rheostat” is shaped by polymorphisms, ligand biochemistry, compartmentalization, and biomechanical forces. The balance between MyD88-dependent signaling and the TRIF–IFN-I axis determines the trajectory of PAH. Prospective therapeutic strategies may include TLR3 agonists, MyD88/NF-κB inhibitors, modulation of IL-6, and combination approaches integrating antiviral therapy with targeted immunomodulation in a precision approach. Full article
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28 pages, 8091 KB  
Article
Identification of Bacterial Networks and Relationship to Host Responses in Early Periodontitis Population over 24 Months
by Aaron R. Biesbrock, Sancai Xie, Ping Hu, Cheryl S. Tansky, Xingtao Wei, Hao Ye, Benjamin Circello, Avi Zini, Guy Tobias, Makio Tamura and Mirjana Parlov
Int. J. Mol. Sci. 2025, 26(22), 10823; https://doi.org/10.3390/ijms262210823 - 7 Nov 2025
Viewed by 633
Abstract
This research examined the effects of daily application of an oral hygiene regimen on the subgingival microbiome over 24 months. Generally healthy adults (107 enrolled, 87 completed) with early periodontitis used a home-care regimen (stannous fluoride paste, cetylpyridinium chloride rinse, power toothbrush, and [...] Read more.
This research examined the effects of daily application of an oral hygiene regimen on the subgingival microbiome over 24 months. Generally healthy adults (107 enrolled, 87 completed) with early periodontitis used a home-care regimen (stannous fluoride paste, cetylpyridinium chloride rinse, power toothbrush, and floss) or usual care (control). Subgingival plaque samples were analyzed enzymatically for bacterial toxins. TLR ligands were measured using TLR-SEAP and TLR-ATP assays. Proinflammatory cytokines and metalloproteinases were quantified via immunoassays. Subgingival DNA was sequenced using a shotgun approach to assess microbial diversity. Increasing levels of bacteria, toxins, TLR activation, inflammatory cytokines, and MMPs were observed for periodontitis versus gingivitis and gingivitis versus healthy sites. The regimen significantly reduced levels of the critical proinflammatory cytokine IL-1β, as well as MMP-1 and MMP-9, at 24 months. By month 6, TLR ligands within subgingival plaques decreased. The abundance of pathogenic bacteria correlated with levels of virulence factors, proinflammatory cytokines, MMPs, and severity of clinical measures. Two distinct constellations of pathogenic bacteria were identified. Gingival sites were categorized into responders and non-responders per clinical symptoms and biomarkers. The regimen yielded more responder sites (70%) versus the control (47%), p = 0.0002914. The regimen reduced pathogenic bacteria, IL-1β, MMP1, and MMP-9, paralleling clinical reductions in periodontal disease. Full article
(This article belongs to the Special Issue Molecular Biology of Periodontal Disease and Periodontal Pathogens)
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15 pages, 3483 KB  
Article
In Vivo Iterative Adjuvant Screening Identifies an Intranasal Vaccine Formulation for Elicitation of Protective Mucosal Immune Responses Against SARS-CoV-2
by Yang Jiao, Sara H. Mahmoud, Chengjin Ye, Yuan Luo, Wei-Chiao Huang, Qinzhe Li, Shiqi Zhou, Yiting Song, Moriya Tsuji, Luis Martinez-Sobrido and Jonathan F. Lovell
Pharmaceutics 2025, 17(11), 1422; https://doi.org/10.3390/pharmaceutics17111422 - 3 Nov 2025
Viewed by 731
Abstract
Background: Intranasal (I.N.) vaccination holds promise to elicit mucosal immunity that counters respiratory pathogens at the site of infection. For subunit protein vaccines, immunostimulatory adjuvants are typically required. Methods: We screened a panel of 22 lipid-phase adjuvants to identify which ones elicited antigen-specific [...] Read more.
Background: Intranasal (I.N.) vaccination holds promise to elicit mucosal immunity that counters respiratory pathogens at the site of infection. For subunit protein vaccines, immunostimulatory adjuvants are typically required. Methods: We screened a panel of 22 lipid-phase adjuvants to identify which ones elicited antigen-specific IgA with I.N. immunization of liposome-displayed SARS-CoV-2 receptor-binding domain (RBD). Results: Initial screening showed the TLR-4 agonist Kdo2-Lipid A (KLA) effectively elicited RBD-specific IgA. A second round of screening identified further inclusion of the invariant NKT cell ligands α-Galactosylceramide (α-GalCer) and its synthetic analog 7DW8-5 as complementary adjuvants for I.N. immunization, resulting in orders-of-magnitude-greater mucosal IgA response relative to intramuscular (I.M.) immunization. The inclusion of cationic lipids conferred capacity for mucosal adhesion and maintained immune responses. In K18 hACE2 transgenic mice, vaccination significantly reduced viral replication and prevented mortality from SARS-CoV-2 challenge. Conclusions: These results point towards the potential for the use of KLA and α-GalCer for I.N. subunit vaccines. Full article
(This article belongs to the Section Nanomedicine and Nanotechnology)
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29 pages, 3985 KB  
Article
Differential Responses of Human iPSC-Derived Microglia to Stimulation with Diverse Inflammogens
by Chiara Wolfbeisz, Julian Suess, Nadine Dreser, Heidrun Leisner, Markus Brüll, Madeleine Fandrich, Nicole Schneiderhan-Marra, Oliver Poetz, Thomas Hartung and Marcel Leist
Cells 2025, 14(21), 1687; https://doi.org/10.3390/cells14211687 - 28 Oct 2025
Viewed by 1905
Abstract
Human microglia are central regulators and actors in brain infections and neuro-inflammatory pathologies. However, access to such cells is limited, and studies systematically mapping the spectrum of their inflammatory states are scarce. Here, we generated microglia-like cells (MGLCs) from human induced pluripotent stem [...] Read more.
Human microglia are central regulators and actors in brain infections and neuro-inflammatory pathologies. However, access to such cells is limited, and studies systematically mapping the spectrum of their inflammatory states are scarce. Here, we generated microglia-like cells (MGLCs) from human induced pluripotent stem cells and characterized them as a robust, accessible model system for studying inflammatory activation. We validated lineage identity through transcriptome profiling, revealing selective upregulation of microglial signature genes and enrichment of microglia/macrophage-related gene sets. MGLCs displayed distinct morphologies and produced stimulus- and time-dependent cytokine secretion profiles upon exposure to diverse inflammatory stimuli, including pro-inflammatory cytokines (TNFα, interferon-γ) and agonists of the Toll-like receptors TLR2 (FSL-1), TLR3 (Poly(I:C)), TLR4 (lipopolysaccharide, LPS), and TLR7 (imiquimod). Transcriptome profiling and bioinformatics analysis revealed distinct activation signatures. Functional assays demonstrated stimulus-specific engagement of NFκB and JAK-STAT signaling pathways. The shared NFκB nuclear translocation response of TLR ligands and TNFα was reflected in overlapping transcriptome profiles: they shared modules (e.g., oxidative stress response and TNFα-related signaling) identified by weighted gene co-expression network analysis. Finally, the potential consequences of microglia activation for neighboring cells were studied on the example of microglia-astrocyte crosstalk. The capacity of MGLC supernatants to stimulate astrocytes was measured by quantifying astrocytic NFκB translocation. MGLCs stimulated with FSL-1, LPS, or Poly(I:C) indirectly activated astrocytes via a strictly TNFα-dependent mechanism, highlighting the role of soluble mediators in the signal propagation. Altogether, this platform enables a dissection of microglia activation states and multi-parametric characterization of subsequent neuroinflammation. Full article
(This article belongs to the Collection Feature Papers in 'Cells of the Nervous System' Section)
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14 pages, 700 KB  
Review
Molecular Constraints of Sperm Sex Sorting via TLR7/8 Activation
by Alikhan Magauiya, Kausar Torebek, Filipp Georgijevič Savvulidi, Martin Ptáček, Christopher LeBrun, Lucie Langerová, Elbosyn Sagdat, Saltanat Baikoshkarova and Nurlan Malmakov
Animals 2025, 15(20), 2976; https://doi.org/10.3390/ani15202976 - 14 Oct 2025
Viewed by 1110
Abstract
In modern livestock, the demand for sperm sex selection technologies is high, as the ability to deliberately produce offspring of a specific sex offers significant economic advantages. Traditionally, sperm sorting is performed using Fluorescence-Activated Cell Sorting. However, the flow cytometric method is expensive, [...] Read more.
In modern livestock, the demand for sperm sex selection technologies is high, as the ability to deliberately produce offspring of a specific sex offers significant economic advantages. Traditionally, sperm sorting is performed using Fluorescence-Activated Cell Sorting. However, the flow cytometric method is expensive, technically complex, and associated with reduced sperm viability. An alternative promising method involves the use of Toll-like TLR7/8 receptors for the selective binding of spermatozoa of a particular sex. It was discovered previously that the activation of TLR7/8 by its ligand(s) selectively inhibits the motility of X-bearing sperm without affecting the motility of Y-bearing sperm. The swim-up technique, which separates sperm based on sex chromosome type by isolating fractions enriched in either X- or Y-bearing gametes due to differences in their motility, can be used with this method. Sperm sex sorting via the TLR7/8 activation is cheap, technically non-complex, and does not affect sperm viability negatively. The goal of this review is to provide an overview of the TLR7/8-dependent sperm sorting method. Further, we discuss why the method of sperm sorting via TLR7/8 activation is successfully implemented in some animal species (such as murine, caprine, ovine, and bovine) but fails in others, like swine and canine. Full article
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32 pages, 1390 KB  
Review
Discovery of Personalized Treatment for Immuno-Metabolic Depression—Focus on 11beta Hydroxysteroid Dehydrogenase Type 2 (11betaHSD2) and Toll-like Receptor 4 (TLR4) Inhibition with Enoxolone
by Harald Murck
Pharmaceuticals 2025, 18(10), 1517; https://doi.org/10.3390/ph18101517 - 10 Oct 2025
Viewed by 1963
Abstract
Treatment options for major depression are limited: only about one-third of patients achieve remission with first line treatments with no established predictive markers. Parameters associated with treatment refractory depression, including metabolic markers (increased BMI, increased triglyceride levels), inflammation markers (C-reactive protein, CRP), autonomic [...] Read more.
Treatment options for major depression are limited: only about one-third of patients achieve remission with first line treatments with no established predictive markers. Parameters associated with treatment refractory depression, including metabolic markers (increased BMI, increased triglyceride levels), inflammation markers (C-reactive protein, CRP), autonomic disturbances (reduced blood pressure, reduced heart rate variability), and brain morphology changes (increased volume of the choroid plexus and brain ventricle volumes), may serve such purpose. These features can be linked mechanistically to an increase in aldosterone plasma concentration due to a reduced mineralocorticoid receptor (MR) sensitivity. The primary CNS target of aldosterone is the nucleus of the solitary tract (NTS), which is also the entry point of the vagus nerve. This nucleus integrates signals from endocrine, inflammatory, chemoreceptive, and physiological parameters, including blood pressure. In search of a mechanism to overcome this pathology, we identified a molecule which is derived from the licorice plant glycyrrhiza glabra, namely glycyrrhizin and its biologically active metabolite enoxolone. These molecules potentially reverse the above-described pathology. They inhibit the enzyme 11beta hydroxysteroid-dehydrogenase type 2 (11betaHSD2) and the toll-like receptor 4 (TLR4). 11betaHSD2 regulates the activity of the mineralocorticoid receptor (MR) by degrading cortisol/corticosterone, which allows aldosterone to bind to the MR. TLR4 is the ligand for lipopolysaccharide (LPS, endotoxin) and trigger of innate immunity. Consequently, patients with increased inflammation markers, increased aldosterone, or low blood pressure may preferentially benefit from the treatment with glycyrrhizin/enoxolone. Importantly, these patients can be identified BEFORE treatment is initiated. Clinically, patients sharing these biological indicators are primarily young females or patients with a history of childhood trauma. A combination of enoxolone with standard antidepressants may therefore avoid a trial-and-error approach and allow to achieve recovery faster. Full article
(This article belongs to the Special Issue Discovery of Novel Antidepressants and Anxiolytics)
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17 pages, 4925 KB  
Article
Bacterial Infections and Their Cell Wall Ligands Differentially Modulate Doxorubicin Sensitivity in Triple-Negative Breast Cancer Cells
by Sima Kianpour Rad, Runhao Li, Kenny K. L. Yeo, Fangmeinuo Wu, Yoko Tomita, Timothy J. Price, Wendy V. Ingman, Amanda R. Townsend and Eric Smith
Microorganisms 2025, 13(10), 2317; https://doi.org/10.3390/microorganisms13102317 - 7 Oct 2025
Cited by 1 | Viewed by 780
Abstract
Background: Triple-negative breast cancer (TNBC) is an aggressive subtype with limited treatment options and poor clinical outcomes. Emerging evidence suggests that the tumor-associated microbiome may influence disease progression and therapy response. Methods: We investigated how the Gram-negative bacterium Pseudomonas aeruginosa and Gram-positive bacterium [...] Read more.
Background: Triple-negative breast cancer (TNBC) is an aggressive subtype with limited treatment options and poor clinical outcomes. Emerging evidence suggests that the tumor-associated microbiome may influence disease progression and therapy response. Methods: We investigated how the Gram-negative bacterium Pseudomonas aeruginosa and Gram-positive bacterium Staphylococcus aureus, together with their cell wall components lipopolysaccharide (LPS) and lipoteichoic acid (LTA), modulate doxorubicin (DOX) efficacy in TNBC cells. Using gentamicin protection combined with flow cytometry of eFluor 450-labeled bacteria and CFU quantification, we assessed bacterial uptake, persistence, and effects on drug response in MDA-MB-468, MDA-MB-231, and MDA-MB-453 cells. Results: Both bacteria entered TNBC cells and survived for several days in a cell line-dependent manner. Notably, bacterial infection and purified cell wall ligands (LPS and LTA) significantly increased DOX accumulation and enhanced cytotoxicity in MDA-MB-468 and MDA-MB-231, but not in MDA-MB-453. The similar effects of LPS and LTA implicate Toll-like receptor signaling (TLR2 and TLR4) in modulating drug uptake. Conclusions: These findings demonstrate that bacterial infection and associated ligands can enhance doxorubicin uptake and cytotoxicity in TNBC cells, implicating TLR signaling as a potential contributor. Our results highlight the importance of host–microbe interactions in shaping chemotherapy response and warrant further investigation into their therapeutic relevance. Full article
(This article belongs to the Collection Microbiomes and Cancer: A New Era in Diagnosis and Therapy)
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14 pages, 2598 KB  
Article
Impact of Particulate Matter on the Exacerbation of Immunoglobulin A Nephropathy: An Animal Experimental Study
by Minhyeok Lee, Yeon Woo Lee, Daeun Kang, Ji Woong Son, Wan Jin Hwang, Sin Yung Woo, Mi Jin Hong, Yusin Pak, Se-Hee Yoon, Won Min Hwang, Sung-Ro Yun and Yohan Park
Int. J. Mol. Sci. 2025, 26(19), 9387; https://doi.org/10.3390/ijms26199387 - 25 Sep 2025
Viewed by 752
Abstract
Particulate matter (PM) exposure is linked to chronic kidney disease; however, its effect on immunoglobulin A (IgA) nephropathy (IgAN) remains unclear. We investigated whether PM exposure exacerbates IgAN in a mouse model. HIGA mice (IgAN model) and BALB/c controls were exposed to PM [...] Read more.
Particulate matter (PM) exposure is linked to chronic kidney disease; however, its effect on immunoglobulin A (IgA) nephropathy (IgAN) remains unclear. We investigated whether PM exposure exacerbates IgAN in a mouse model. HIGA mice (IgAN model) and BALB/c controls were exposed to PM in a sealed chamber for 13 weeks. Lung Toll-like receptor 9 (TLR9) expression, serum aberrantly glycosylated IgA, A proliferation-inducing ligand (APRIL) levels, mesangial IgA deposition, and kidney pathology were assessed. RNA sequencing of splenic B cells was performed to evaluate immune-related gene expression. PM exposure increased lung TLR9 expression in both strains, particularly around pigment-laden macrophages. HIGA mice showed elevated aberrant IgA and APRIL levels, with aggravated mesangial expansion and IgA deposition. Transcriptomic analysis revealed immune dysregulation in splenic B cells of PM-exposed HIGA mice. Our findings provide experimental evidence that PM exposure aggravates IgAN via TLR9-mediated mucosal immune activation, leading to aberrant IgA glycosylation and mesangial deposition. These findings emphasize that reducing PM exposure may benefit patients with IgAN. Full article
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25 pages, 8714 KB  
Article
Cell Line-Dependent Internalization, Persistence, and Immunomodulatory Effects of Staphylococcus aureus in Triple-Negative Breast Cancer
by Sima Kianpour Rad, Runhao Li, Kenny K. L. Yeo, Clare Cooksley, Gohar Shaghayegh, Sarah Vreugde, Fangmeinuo Wu, Yoko Tomita, Timothy J. Price, Wendy V. Ingman, Amanda R. Townsend and Eric Smith
Cancers 2025, 17(18), 2947; https://doi.org/10.3390/cancers17182947 - 9 Sep 2025
Cited by 2 | Viewed by 2062
Abstract
Background: Triple-negative breast cancer (TNBC) is an aggressive subtype with limited therapeutic options and inconsistent response to immune checkpoint inhibitors (ICIs). Emerging evidence indicates that tumor-associated bacteria may shape immune signaling and alter immunotherapy outcomes. Here, we investigated whether Staphylococcus aureus invades TNBC [...] Read more.
Background: Triple-negative breast cancer (TNBC) is an aggressive subtype with limited therapeutic options and inconsistent response to immune checkpoint inhibitors (ICIs). Emerging evidence indicates that tumor-associated bacteria may shape immune signaling and alter immunotherapy outcomes. Here, we investigated whether Staphylococcus aureus invades TNBC cells, persists intracellularly, and modulates PD-L1 expression. Methods: Using eFluor450-labeled S. aureus for flow cytometry, gentamicin protection assays, CFU quantification, and transmission electron microscopy, we assessed bacterial uptake and persistence in six TNBC cell lines and a non-tumorigenic control. PD-L1, TLR2, and STAT1 activation were evaluated after infection or TLR2 ligand treatment ± IFN-γ. Results: At multiplicity of infection (MOI) of 10, S. aureus internalized into 67% of MDA-MB-468 and 54% of MDA-MB-231, with intermediate uptake in Hs578T (27%) and BT-549 (24%) and only 0.5–9% in low-uptake lines (MDA-MB-453, CAL-51, MCF-12A). High-uptake lines exhibited marked cytotoxicity and reduced proliferation, with MDA-MB-468 showing an 82% drop in viability at 2 h and a 74% decrease after 5 d, whereas low-uptake lines showed minimal impact. Persistence lasted >7 d in MDA-MB-231 but only 3–5 days in others. IFN-γ plus S. aureus significantly amplified PD-L1, with up to a 2.9-fold increase in MDA-MB-468 and 1.5-fold in MDA-MB-231, but no effect in low-uptake lines. TLR2 agonists modestly increased PD-L1 in high-TLR2-expressing lines and synergized with IFN-γ. These effects were accompanied by STAT1 phosphorylation, supporting a TLR2/STAT1 axis linking bacterial sensing to immune checkpoint regulation. Conclusions: Together, these findings identify S. aureus as a modulator of immune signaling in TNBC and highlight the potential for microbial factors to influence ICI responsiveness. Targeting tumor–bacteria interactions may represent a novel strategy to enhance immunotherapy efficacy in breast cancer. Full article
(This article belongs to the Special Issue New Insights into Microbial-Based Cancer Therapy)
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15 pages, 2856 KB  
Article
Imiquimod (R837), a TLR7-Specific Agonist, Regulates Boar Sperm Motility via PI3K/GSK3α/β/Hexokinase Pathway
by Weijing Zhang, Adedeji O. Adetunji, Wenxian Zeng, Eslam M. Bastawy, Lingjiang Min, Nengshui Ding and Zhendong Zhu
Biology 2025, 14(9), 1182; https://doi.org/10.3390/biology14091182 - 2 Sep 2025
Viewed by 1041
Abstract
Mammalian sperm has a high metabolic activity and primarily relies on glycolysis and mitochondrial oxidative phosphorylation for energy supply. It has been reported that imiquimod (R837), a specific ligand of TLR7 protein, reduces the motility of sperm. However, the specific molecular mechanism by [...] Read more.
Mammalian sperm has a high metabolic activity and primarily relies on glycolysis and mitochondrial oxidative phosphorylation for energy supply. It has been reported that imiquimod (R837), a specific ligand of TLR7 protein, reduces the motility of sperm. However, the specific molecular mechanism by which TLR7 modulates boar sperm is unclear. In this study, the effect of R837, a Toll-like receptor 7 (TLR7) agonist, on boar sperm motility was investigated. Sperm samples were incubated with varying concentrations of R837 (0 to 0.8 µM) at different time points (30, 60, and 90 min). Findings reveal for the first time that TLR7 protein, a key component of the immune system’s Toll-like receptors, is predominantly localized in the middle section of the boar sperm tail, with a smaller concentration observed in the neck. Also, immunofluorescence (IF) revealed that approximately half of the boar sperm sample expressed TLR7. Furthermore, the TLR7 agonist influenced glycolytic hexokinase activity and mitochondrial function via the PI3K-GSK3β signaling pathway. It also selectively inhibited motility in the lower-layer sperm, while motility in the upper-layer sperm remained unaffected. Additionally, this study determined that incubation conditions for boar sperm with 0.2 μM R837 at 37 °C for 60 min yielded the most pronounced inhibition of forward motility in the lower layer of sperm, without compromising the integrity of the acrosome or plasma membrane. The present study reveals the crucial role of R837 in boar sperm motility and highlights TLR7 as an important protein that regulates boar sperm energy metabolism. Full article
(This article belongs to the Special Issue The Biology of Animal Reproduction)
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21 pages, 2662 KB  
Article
CX3CR1–TLR4 Axis as a Shared Neuroimmune Target in COVID-19 and Epilepsy: Integrative Transcriptomics and Gabapentin Repositioning
by Nannan Pan, Penghui Cao, Ben Chen, Li Chen, Xuezhen Liao and Yuping Ning
Biomedicines 2025, 13(9), 2133; https://doi.org/10.3390/biomedicines13092133 - 31 Aug 2025
Cited by 1 | Viewed by 1138
Abstract
Introduction: Neuroinflammation is a common pathological hallmark of Coronavirus Disease 2019 (COVID-19) and epilepsy; however, their shared immunogenomic mechanisms remain poorly defined. This study explores shared immune-inflammatory transcriptomic signatures and identifies potential repositioning therapeutics. Methods: We integrated single-cell RNA-seq data from peripheral blood [...] Read more.
Introduction: Neuroinflammation is a common pathological hallmark of Coronavirus Disease 2019 (COVID-19) and epilepsy; however, their shared immunogenomic mechanisms remain poorly defined. This study explores shared immune-inflammatory transcriptomic signatures and identifies potential repositioning therapeutics. Methods: We integrated single-cell RNA-seq data from peripheral blood mononuclear cells (PBMCs) of COVID-19 patients and healthy donors (GSE149689), and bulk RNA-seq data from hippocampal tissue of patients with Temporal Lobe Epilepsy with Hippocampal Sclerosis (TLE-HS) and healthy controls (GSE256068). Common Differentially Expressed Genes (DEGs) were identified and subjected to GO/KEGG enrichment, a PPI network, hub gene detection (cytoHubba), and transcriptional regulation analysis (ENCODE-based TF/miRNA networks). Drug repositioning was performed using the LINCS L1000 database. Results: We identified 25 DEGs shared across datasets, including 22 upregulated genes enriched in cytokine–cytokine receptor interaction, NF-κB, and Toll-like receptor pathways. PPI analysis revealed a CX3CR1–TLR4-centered immune module. Gabapentin emerged as a promising repositioning candidate with potential to downregulate CX3CR1, TLR4, and selectin P ligand (SELPLG). Receiver Operating Characteristic (ROC) analysis confirmed the diagnostic value of these targets (AUC > 0.90 in epilepsy). A mechanistic model was proposed to illustrate Gabapentin’s dual action on microglial polarization and cytokine suppression. Conclusions: Our results reveal a shared CX3CR1–TLR4–NF-κB inflammatory axis in COVID-19 and epilepsy, supporting Gabapentin as a potential dual-action immunomodulator. These findings reveal a previously underappreciated immunomodulatory role for Gabapentin, providing mechanistic rationale for its repositioning in neuroinflammatory conditions beyond seizure control. Full article
(This article belongs to the Section Neurobiology and Clinical Neuroscience)
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